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Sample records for continuous emulsion polymerization

  1. Impact of Industrial Grade Modified PVA to Vinyl Acetate Semi-continuous Emulsion Polymerization and Properties of Final Product

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    Mindaugas DUBININKAS

    2013-03-01

    Full Text Available Successful vinyl acetate radical emulsion polymerization in water with different type of industrial grade poly(vinyl alcohol were produced by semi continuous way. The poly(vinyl alcohol type has crucial impact on dispersion rheological as well on films and bonding strength properties. It should be stated that the films containing modified poly (vinyl alcohol has better water resistance and mechanical properties. Poly(vinyl alcohol with higher ethylene moieties content and high hydrolization degree determines extremely low viscosity of final dispersion.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3823

  2. Polymerization in emulsion microdroplet reactors

    Science.gov (United States)

    Carroll, Nick J.

    The goal of this research project is to utilize emulsion droplets as chemical reactors for execution of complex polymerization chemistries to develop unique and functional particle materials. Emulsions are dispersions of immiscible fluids where one fluid usually exists in the form of drops. Not surprisingly, if a liquid-to-solid chemical reaction proceeds to completion within these drops, the resultant solid particles will possess the shape and relative size distribution of the drops. The two immiscible liquid phases required for emulsion polymerization provide unique and complex chemical and physical environments suitable for the engineering of novel materials. The development of novel non-ionic fluorosurfactants allows fluorocarbon oils to be used as the continuous phase in a water-free emulsion. Such emulsions enable the encapsulation of almost any hydrocarbon compound in droplets that may be used as separate compartments for water-sensitive syntheses. Here, we exemplify the promise of this approach by suspension polymerization of polyurethanes (PU), in which the liquid precursor is emulsified into droplets that are then converted 1:1 into polymer particles. The stability of the droplets against coalescence upon removal of the continuous phase by evaporation confirms the formation of solid PU particles. These results prove that the water-free environment of fluorocarbon based emulsions enables high conversion. We produce monodisperse, cross-linked, and fluorescently labeled PU-latexes with controllable mesh size through microfluidic emulsification in a simple one-step process. A novel method for the fabrication of monodisperse mesoporous silica particles is presented. It is based on the formation of well-defined equally sized emulsion droplets using a microfluidic approach. The droplets contain the silica precursor/surfactant solution and are suspended in hexadecane as the continuous oil phase. The solvent is then expelled from the droplets, leading to

  3. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

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    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  4. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid.

    Science.gov (United States)

    Liu, Hongzhu; Bian, Jiming; Wang, Zhonggang; Hou, Chuan-Jin

    2017-01-22

    Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), n-butyl acrylate (BA), Veova 10, and acrylic acid (AA). The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV) accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  5. Polymerization rate and mechanism of ultrasonically initiated emulsion polymerization of n-butyl acrylate.

    Science.gov (United States)

    Xia, Hesheng; Wang, Qi; Liao, Yongqin; Xu, Xi; Baxter, Steven M; Slone, Robert V; Wu, Shuguang; Swift, Graham; Westmoreland, David G

    2002-07-01

    The factors affecting the induction period and polymerization rate in ultrasonically initiated emulsion polymerization of n-butyl acrylate (BA) were investigated. The induction period takes only an instant in ultrasonically initiated emulsion polymerization of BA without any added initiator by enhancing the N2 flow rate. Increasing temperature, power output and SDS concentration, decreasing the monomer concentration results in further decreasing induction period and enhanced polymerization rate. Under optimized reaction conditions the conversion of BA reaches 92% in 11 min. The polymerization rate can be controlled by varying reaction parameters. The apparatus of ultrasonically initiated semi-continuous and continuous emulsion polymerization were set up and the feasibility was first studied. Based on the experimental results, a free radical polymerization mechanism for ultrasonically initiated emulsion polymerization was proposed, including the sources of the radicals, the process of radical formation, the locus of polymerization and the polymerization process. Compared with conventional emulsion polymerization, where the radicals come from thermal decomposition of a chemical initiator, ultrasonically initiated emulsion polymerization has attractive features such as no need for a chemical initiator, lower reaction temperature, faster polymerization rate, and higher molecular weight of the polymer prepared.

  6. DISPERSION PRODUCTION BY SEMI-CONTINUOUS RADICAL VINYL ACETATE EMULSION POLYMERIZATION WITH SILANE CO-MONOMER AND CHARACTERIZATION OF FINAL PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    Mindaugas Dubininkas; Gintaras Buika

    2013-01-01

    Vinyl acetate radical emulsion polymerization in water with GF51 silane co-monomer was performed by semi continuous way.The GF51 impacts on dispersion rheology as well on films and bonding strength properties were determined.It should be stated that even low quantities of GF51 (up to 6% from VAc) determined high viscosity of dispersions.The GF51 modified films have low water absorption and high affinity to glass.Molecular mass and thermal properties of GF51 modified polymers were determined accordingly.

  7. Kinetics of crosslinking in emulsion polymerization

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    Ghielmi, A.; Fiorentino, S.; Morbidelli, M. [Universitaetstrasse Zuerich (Switzerland)] [and others

    1996-12-31

    A mathematical model for evaluating the chain length distribution of nonlinear polymers produced in emulsions is presented. The heterogeneous emulsion polymerization process is described. The aim of the analysis is the distribution of active polymer chains and pairs of chains with a given growth time in latex particles in state.

  8. High temperature structural, polymeric foams from high internal emulsion polymerization

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    Hoisington, M.A.; Duke, J.R.; Apen, P.G.

    1996-02-01

    In 1982, a high internal phase emulsion (HIPE) polymerization process to manufacture microcellular, polymeric foam systems was patented by Unilever. This patent discloses a polymerization process that occurs in a water-in-oil emulsion in which the water represents at least 76% of the emulsion by volume. The oil phase consists of vinyl monomers such as styrene and acrylates that are crosslinked by divinyl monomers during polymerization. After polymerization and drying to remove the water phase, the result is a crosslinked polymer foam with an open cell microstructure that is homogeneous throughout in terms of morphology, density, and mechanical properties. Since 1982, numerous patents have examined various HIPE polymerized foam processing techniques and applications that include absorbents for body fluids, cleaning materials, and ion exchange systems. All the published HIPE polymerized foams have concentrated on materials for low temperature applications. Copolymerization of styrene with maleic anhydride and N-substituted maleimides to produce heat resistant thermoplastics has been studied extensively. These investigations have shown that styrene will free radically copolymerize with N-substituted maleimides to create an alternating thermoplastic copolymer with a Tg of approximately 200{degrees}C. However, there are many difficulties in attempting the maleimide styrene copolymerization in a HIPE such as lower polymerization temperatures, maleimide solubility difficulties in both styrene and water, and difficulty obtaining a stable HIPE with a styrene/maleimide oil phase. This work describes the preparation of copolymer foams from N-ethylmaleimide and Bis(3-ethyl-5-methyl-4-maleimide-phenyl)methane with styrene based monomers and crosslinking agents.

  9. Sterically and electrosterically stabilized emulsion polymerization. Kinetics and preparation.

    Science.gov (United States)

    Capek, Ignác

    2002-10-21

    The principal subject discussed in the current paper is the radical polymerization in the aqueous emulsions of unsaturated monomers (styrene, alkyl (meth)acrylates, etc.) stabilized by non-ionic and ionic/non-ionic emulsifiers. The sterically and electrosterically stabilized emulsion polymerization is a classical method which allows to prepare polymer lattices with large particles and a narrow particle size distribution. In spite of the similarities between electrostatically and sterically stabilized emulsion polymerizations, there are large differences in the polymerization rate, particle size and nucleation mode due to varying solubility of emulsifiers in oil and water phases, micelle sizes and thickness of the interfacial layer at the particle surface. The well-known Smith-Ewart theory mostly applicable for ionic emulsifier, predicts that the number of particles nucleated is proportional to the concentration of emulsifier up to 0.6. The thin interfacial layer at the particle surface, the large surface area of relatively small polymer particles and high stability of small particles lead to rapid polymerization. In the sterically stabilized emulsion polymerization the reaction order is significantly above 0.6. This was ascribed to limited flocculation of polymer particles at low concentration of emulsifier, due to preferential location of emulsifier in the monomer phase. Polymerization in the large particles deviates from the zero-one approach but the pseudo-bulk kinetics can be operative. The thick interfacial layer can act as a barrier for entering radicals due to which the radical entry efficiency and also the rate of polymerization are depressed. The high oil-solubility of non-ionic emulsifier decreases the initial micellar amount of emulsifier available for particle nucleation, which induces non-stationary state polymerization. The continuous release of emulsifier from the monomer phase and dismantling of the non-micellar aggregates maintained a high level of

  10. Effect of Polymerization Condition on Particle Size Distribution in St/BA/MAA Emulsion Polymerization Process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A series of St/BA/MAA emulsion polymerizations was carried out. By using PCS (photon correlation spectroscopy), the particle size distribution(PSD) of the whole St/BA/MAA emulsion polymerization process was gotten easily and quickly. The effect of polymerization condition on PSD in St/BA/MAA emulsion process was discussed.

  11. A COMPARISON OF DIFFERENT MODELING APPROACHES FOR THE SIMULATION OF THE TRANSIENT AND STEADY-STATE BEHAVIOR OF CONTINUOUS EMULSION POLYMERIZATIONS IN PULSED TUBULAR REACTORS

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    C. Sayer

    2002-03-01

    Full Text Available Dynamic mathematical models are developed to simulate styrene emulsion polymerization reactions carried out in pulsed tubular reactors. Two different modeling approaches, the tanks-in-series model and the axial dispersion model, are compared. The models developed were validated with experimental data from the literature and used to study the dynamics during transient periods, e.g., the start-up of the reactor and the response to disturbances. The effect of the Peclet number on process variables such as conversion and particle concentration was also verified.

  12. The Morphology of Emulsion Polymerized Latex Particles

    Science.gov (United States)

    Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M < 10{sup 6} g/mol SANS gave zero angle scattering intensities much higher than expected on the basis of a random distribution of labeled molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.

  13. Fluorescent-magnetic Janus particles prepared via seed emulsion polymerization.

    Science.gov (United States)

    Kaewsaneha, Chariya; Bitar, Ahmad; Tangboriboonrat, Pramuan; Polpanich, Duangporn; Elaissari, Abdelhamid

    2014-06-15

    Anisotropic polymeric colloidal or Janus particles possessing simultaneous magnetic and fluorescent properties were successfully prepared via the swelling-diffusion or the in situ emulsion polymerization method. In the swelling-diffusion process, magnetic emulsions (an organic ferrofluid dispersed in aqueous medium) were synthesized and used for seeds of submicron magnetic Janus particles. After swelling the anisotropic particles obtained by 1-pyrene-carboxaldehyde fluorescent dye dissolved in tetrahydrofuran, well-defined fluorescent-magnetic Janus particles were produced. In the in situ emulsion polymerization, styrene monomer mixed with fluorescent dye monomers, i.e., 1-pyrenylmethyl methacrylate (PyMMA) or fluorescein dimethacrylate (FDMA), and an oil-soluble initiator (2,2'-azobis(2-isobutyronitrile)) were emulsified in the presence of magnetic seed emulsions. The confocal microscopic images showed the fluorescent-magnetic Janus particles with high fluorescent intensity when a fluorescent crosslinker monomer FDMA was employed.

  14. A Kinetic Study of the Emulsion Polymerization of Vinyl Acetate

    DEFF Research Database (Denmark)

    Friis, N.; Nyhagen, L.

    1973-01-01

    The emulsion polymerization of vinyl acetate was studied at 50°C. It was found that the rate of polymerization was proportional to the 0.5 power of the initiator concentration and the 0.25 power of the number of particles. The number of particles was proportional to the power 0.5 ± 0.05 of the em...

  15. Thermal Emulsion Polymerization without any Conventional Initiators and Emulsifiers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Stable poly(styrene-co-sodium styrene suffonate) (P(St-NaSS) nanoparticles with broader size distribution were synthesized by thermal emulsion polymerization without any conventional initiators and emulsifiers. The obtained polymer nanoparticles have higher ξpotential, and the particle sizes have broad distribution. The stability of polymer particles originated from the addition of small amounts of ionic comonomer, NaSS, which can act as an emulsifier in somewhat. The monomer conversion could reach up to about 28 wt% in 48 h, and did not increase by further polymerization when higher polymerization temperature (120℃) was employed. This polymerization system may be give some further understand for mechanism of emulsion polymerization.

  16. Investigation on the Inverse Emulsion Polymerization of Acrylic Acid

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time. It was concluded that the inverse micelles were primarily the polymerization reaction sites.

  17. Kinetics of vinyl acetate emulsion polymerization in a pulsed tubular reactor: comparison between experimental and simulation results

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    Sayer C.

    2002-01-01

    Full Text Available A new reactor, the pulsed sieve plate column (PSPC, was developed to perform continuous emulsion polymerization reactions. This reactor combines the enhanced flexibility of tubular reactors with the mixing behavior provided by sieved plates and by the introduction of pulses that is important to prevent emulsion destabilization. The main objective of this work is to study the kinetics of vinyl acetate (VA emulsion polymerization reactions performed in this PSPC. Therefore, both experimental studies and reaction simulations were performed. Results showed that it is possible to obtain high conversions with rather low residence times in the PSPC.

  18. Stabilization of emulsions using polymeric surfactants based on inulin.

    Science.gov (United States)

    Tadros, Th F; Vandamme, A; Levecke, B; Booten, K; Stevens, C V

    2004-05-20

    The use of polymeric surfactants for stabilization of emulsions is described. A brief account of general classification and description of polymeric surfactants is given. This is followed by a description of the adsorption and conformation of polymeric surfactants at interfaces. The theoretical approaches for studying polymer adsorption are briefly described. This is followed by a section on the experimental techniques that can be applied to study adsorption and conformation of polymers at the interface. Examples are given to illustrate the experimental techniques. A section is devoted to the interaction between droplets containing adsorbed polymer layers (steric stabilization). The last section gives results on oil-in-water (O/W) emulsions stabilised with a novel graft copolymeric surfactant based on inulin that has been modified by introducing alkyl groups. Two oils were used, namely Isopar M (isoparaffinic oil) and cyclomethicone. Emulsions prepared using the inulin-based surfactant have large droplets, but this could be significantly reduced by addition of a cosurfactant in the oil phase, namely Span 20. The stability of the emulsions was investigated in water, in 0.5, 1.0, 1.5 and 2 mol dm(-3) NaCl and in 0.5, 1.0, 1.5 and 2 mol dm(-3) MgSO(4). These emulsions were stable for more than 1 year up to 50 degrees C in NaCl concentrations up to 2 mol dm(-3) and 1 mol dm(-3) MgSO(4). This high stability in high electrolyte concentrations could be attributed to the nature of the hydrophilic (stabilizing) polyfructose chain. This was confirmed using cloud point measurements, which showed high hydration of the polyfructose chain in such high electrolyte concentrations. This ensured the long-term physical stability resulting from the strong steric repulsion between the polyfructose chains.

  19. Nanoencapsulation of blocked isocyanates through aqueous emulsion polymerization

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    2008-05-01

    Full Text Available Blocked isocyanates were successfully encapsulated into polystyrene and hydroxyl and amine functionalized polymeric nanospheres via emulsion polymerization. The nanocapsules were characterized via Fourier transform infrared spectroscopy, differential scanning calorimetry and transmission electronic microscopy. The blocked isocyanates generated free isocyanate functionality upon thermal annealing of nanocapsules. This research establishes a novel encapsulating method for release and retention of free isocyanates in aqueous media. These nanocapsules can provide active isocyanates in coatings and adhesive applications, and represent a novel application of nanoencapsulated materials for controlled or delayed active material utilization.

  20. Effect of ultrasonic pretreatment on emulsion polymerization of styrene.

    Science.gov (United States)

    Nagatomo, Daichi; Horie, Takafumi; Hongo, Chizuru; Ohmura, Naoto

    2016-07-01

    This study investigated the effect of pretreatment of ultrasonic irradiation on emulsion polymerization of styrene to propose a process intensification method which gives high conversion, high reaction rate, and high energy efficiency. The solution containing styrene monomer was irradiated by a horn mounted on the ultrasonic transducer with the diameter of 5mm diameter and the frequency of 28 kHz before starting polymerization. The pretreatment of ultrasound irradiation as short as 1 min drastically improved monomer dispersion and increased reaction rate even under the agitation condition with low rotational speed of impeller. Furthermore, the ultrasonic pretreatment resulted in higher monomer concentration in polymer particles and produced larger polymer particles than conventional polymerization without ultrasonic pretreatment.

  1. Detonation behavior of emulsion explosives sensitized with polymeric microballoons

    Science.gov (United States)

    Mendes, Ricardo; Ribeiro, José; Plaksin, Igor; Campos, José

    2013-06-01

    The differences between the detonation behavior of ammonium nitrate based emulsion explosive sensitized with polymeric or with glass microballoons is presented and discussed. Expancel® are hollow polymeric microballoons that contain a hydrocarbon gas. The mean particle size of those particles is 30 μm and their wall thickness is about 0.1 μm. The detonation velocity and the failure diameter of the emulsion explosive sensitized with different amounts of these particles were measured, in cylindrical charges, by ionization pins and optical fibers. The detonation velocity of emulsion explosives shows a non-monotonic evolution with the density with the maximum being reached far below the maximum density. The detonation fails when the density approaches the one of the matrix. The failure diameter increases with increasing density. For low densities the detonation velocity is almost independent of the charge diameter and it is close to the values predict by BKW EoS. The effect of the nature and size of the microballoons on the detonation front curvature and failure diameter was also determined.

  2. Partitioning of Laponite Clay Platelets in Pickering Emulsion Polymerization.

    Science.gov (United States)

    Brunier, Barthélémy; Sheibat-Othman, Nida; Chevalier, Yves; Bourgeat-Lami, Elodie

    2016-01-12

    Partitioning of laponite disklike clay platelets between polymer particles and bulk aqueous phase was investigated in Pickering surfactant-free emulsion polymerization of styrene. Adsorption of laponite clay platelets plays an important role in the stabilization of this system, influencing the particle size and the number of particles, and, hence, the reaction rate. Adsorption isotherms show that, while the laponite clay platelets are almost fully exfoliated in water, they form multilayers on the surface of the polymer particles by the end of polymerization, as confirmed by transmission electron microscopy (TEM). This observation is supported by quartz crystal microbalance, conductivity, and TEM measurements, which reveal interactions between the clay and polystyrene, as a function of the ionic strength. The strong adsorption of clay platelets leaves a low residual concentration in the aqueous phase that cannot cause further nucleation of polymer particles, as demonstrated during seeded emulsion polymerization experiments in the presence of a high excess of clay. A Brunauer-Emmett-Teller (BET)-type model for laponite adsorption on polystyrene particles matches the adsorption isotherms.

  3. Pickering emulsion templated interfacial atom transfer radical polymerization for microencapsulation.

    Science.gov (United States)

    Li, Jian; Hitchcock, Adam P; Stöver, Harald D H

    2010-12-01

    This Article describes a new microencapsulation method based on a Pickering emulsion templated interfacial atom transfer radical polymerization (PETI-ATRP). Cationic LUDOX CL nanoparticles were coated electrostatically with an anionic polymeric ATRP initiator, poly(sodium styrene sulfonate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PSB), prepared by radical copolymerization of sodium styrene sulfonate and 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). The resulting PSB-modified CL particles were surface active and could be used to stabilize oil-in-water Pickering emulsions. ATRP of water-soluble cross-linking monomers, confined to the oil-water interface by the surface-bound PSB, then led to nanoparticle/polymer composite shells. This method allowed encapsulation of core solvents (xylene, hexadecane, perfluoroheptane) with different solubility parameters. The microcapsule (MC) wall chemistry could accommodate different monomers, demonstrating the versatility of this method. Double-walled MCs were formed by sequentially carrying out PETI-ATRP and in situ polymerization of encapsulated monomers. The double-walled structure was verified by both transmission electron microscopy (TEM) and scanning transmission X-ray microscopy (STXM).

  4. Optimal control of batch emulsion polymerization of vinyl chloride

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    Damslora, Andre Johan

    1998-12-31

    The highly exothermic polymerization of vinyl chloride (VC) is carried out in large vessels where the heat removal represents a major limitation of the production rate. Many emulsion polymerization reactors are operated in such a way that a substantial part of the heat transfer capacity is left unused for a significant part of the total batch time. To increase the reaction rate so that it matches the heat removal capacity during the course of the reaction, this thesis proposes the use of a sufficiently flexible initiator system to obtain a reaction rate which is high throughout the reaction and real-time optimization to compute the addition policy for the initiator. This optimization based approach provides a basis for an interplay between design and control and between production and research. A simple model is developed for predicting the polymerization rate. The model is highly nonlinear and open-loop unstable and may serve as an interesting case for comparison of nonlinear control strategies. The model is fitted to data obtained in a laboratory scale reactor. Finally, the thesis discusses optimal control of the emulsion polymerization reactor. Reduction of the batch cycle time is of major economic importance, as long as the quality parameters are within their specifications. The control parameterization had a major influence on the performance. A differentiable spline parameterization was applied and the optimization is illustrated in a number of cases. The best performance is obtained when the reactor temperature is obtained when the optimization is combined with some form of closed-loop control of the reactor temperature. 112 refs., 48 figs., 4 tabs.

  5. Hierarchical Porous Polymer Beads Prepared by Polymerization-induced Phase Separation and Emulsion-template in a Microfluidic Device

    Institute of Scientific and Technical Information of China (English)

    Wei-cai Wang; Yan-xiong Pan; Kai Shi; Chao Peng; Xiang-ling Ji

    2014-01-01

    Porous polymer beads (PPBs) containing hierarchical bimodal pore structure with gigapores and meso-macropores were prepared by polymerization-induced phase separation (PIPS) and emulsion-template technique in a glass capillary microfluidic device (GCMD).Fabrication procedure involved the preparation of water-in-oil emulsion by emulsifying aqueous solution into the monomer solution that contains porogen.The emulsion was added into the GCMD to fabricate the (water-in-oil)-in-water double emulsion droplets.The flow rate of the carrier continuous phase strongly influenced the formation mechanism and size of droplets.Formation mechanism transformed from dripping to jetting and size of droplets decreased from 550 μm to 250 μm with the increase in flow rate of the carrier continuous phase.The prepared droplets were initiated for polymerization by on-line UV-irradiation to form PPBs.The meso-macropores in these beads were generated by PIPS because of the presence ofporogen and gigapores obtained from the emulsion-template.The pore morphology and pore size distribution of the PPBs were investigated extensively by scanning electron microscopy and mercury intrusion porosimetry (MIP).New pore morphology was formed at the edge of the beads different from traditional theory because of different osmolarities between the water phase of the emulsion and the cartier continuous phase.The morphology and proportion of bimodal pore structure can be tuned by changing the kind and amount of porogen.

  6. Synthesis of anisotropic nanoparticles by seeded emulsion polymerization.

    Science.gov (United States)

    Mock, Eric B; De Bruyn, Hank; Hawkett, Brian S; Gilbert, Robert G; Zukoski, Charles F

    2006-04-25

    Anisotropic polystyrene nanoparticles of diameters below 0.5 microm were prepared by coating the surface of cross-linked polystyrene latex particles with a thin hydrophilic polymer layer prior to swelling the particles with styrene and then initiating second-stage free-radical polymerization. Conditions were found so that all particles had uniform asymmetry. The effect of surface chemistry on the development of particle anisotropy during seeded emulsion polymerization of sub-0.5 microm diameter particles was studied. The extent and uniformity of the anisotropy of the final particles depended strongly on the presence of the hydrophilic surface coating. Systematic variation of the degree of hydrophilicity of the surface coating provided qualitative insight into the mechanism responsible for anisotropy. Conditions were chosen so that the surface free energy favored the extrusion of a hydrophobic bulge of monomer on the hydrophilic surface of the particle during the swelling phase: the presence of a hydrophilic layer on the particle surface causes this asymmetry to be favored above uniform wetting of the particle surface by the monomer. Kinetic effects, arising from the finite time required for the seed to swell with the monomer, also play a role.

  7. PREPARATION AND CHARACTERIZATION OF AFFINITY POLYMER BASIC MICROSPHERES BY SOAP-FREE EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Jing-ning Lv; Shi-jiang Fang; Lei Chen

    2009-01-01

    Poly(styrene-co-glycidyl methacrylate) latex microspheres with uniform size and high-density epoxy groups on the surface were prepared by soap-free emulsion polymerization with batch wise operation mode in the presence of 2,2'azobis(2-methylpropionamidine) dihydrochloride as an initiator.The kinetics of soap-free emulsion polymerization and the effects of polymerization factors were examined.In addition,the optimum polymerization conditions of poly(styrene-coglycidyl methacrylate) latex microspheres for immobilization of biomolecules were obtained.

  8. Influences of Electrolytes on Soap-Free P(ST-MMA-AA) Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    Zeping LI; Ronglong LI; Yi DU; Chengyou KAN; Deshan LIU

    2005-01-01

    @@ 1Introduction Functional polymer microspheres are kinds of polymer particles with special structures, morphologies or functional groups[1] , and have been gained much attention because of their specific properties and their application since 1980s. Although some researches have investigated that the latex particle size and its distribution,as well as the stability of polymerization and the resultant latex were strongly influenced by introducing electrolyte into the emulsion polymerization system[2] , few of them focused on the systematic study of electrolytes on the soap-free emulsion polymerization, which is considered as a conventional approach to synthesize functional polymer microspheres with clean surfaces[2]. In this presentation, the influences of variety and dosage of electrolytes on soap-free emulsion polymerization of St, MMA and AA were studied, and a series of micron or submicron sized latex particles with narrow distribution were obtained.

  9. Effects of water phase concentration on the emulsion polymerization of polyaniline

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The emulsion polymerization of aniline in three-phase system of xylene-functionalized protonic acid-water was carried out using (NH4)2S2O4 as oxidant. The influences of water phase concentration on the viscosity, conductivity, transmittance of polyaniline(PAN) latex and its powders were studied. The results show that the properties of PAN prepared through the emulsion polymerization are influenced by the amount of water used in the polymerization. The morphology of PAN varies with the water phase concentration used in the polymerization, which may result in the change of properties of PAN latex and its powders. When the volume fraction of water (φ) is about 20%-30%, the prepared PAN powder has higher conductivity, and the PAN latex has appropriate viscosity and particle size. The consumption of xylene was reduced at high φ value.

  10. An easily regenerable enzyme reactor prepared from polymerized high internal phase emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, Guihua, E-mail: guihuaruan@hotmail.com [Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guangxi 541004 (China); Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004 (China); Wu, Zhenwei; Huang, Yipeng; Wei, Meiping; Su, Rihui [Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guangxi 541004 (China); Du, Fuyou, E-mail: dufu2005@126.com [Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guangxi 541004 (China); Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Area, Guilin University of Technology, Guilin 541004 (China)

    2016-04-22

    A large-scale high-efficient enzyme reactor based on polymerized high internal phase emulsion monolith (polyHIPE) was prepared. First, a porous cross-linked polyHIPE monolith was prepared by in-situ thermal polymerization of a high internal phase emulsion containing styrene, divinylbenzene and polyglutaraldehyde. The enzyme of TPCK-Trypsin was then immobilized on the monolithic polyHIPE. The performance of the resultant enzyme reactor was assessed according to the conversion ability of N{sub α}-benzoyl-L-arginine ethyl ester to N{sub α}-benzoyl-L-arginine, and the protein digestibility of bovine serum albumin (BSA) and cytochrome (Cyt-C). The results showed that the prepared enzyme reactor exhibited high enzyme immobilization efficiency and fast and easy-control protein digestibility. BSA and Cyt-C could be digested in 10 min with sequence coverage of 59% and 78%, respectively. The peptides and residual protein could be easily rinsed out from reactor and the reactor could be regenerated easily with 4 M HCl without any structure destruction. Properties of multiple interconnected chambers with good permeability, fast digestion facility and easily reproducibility indicated that the polyHIPE enzyme reactor was a good selector potentially applied in proteomics and catalysis areas. - Graphical abstract: Schematic illustration of preparation of hypercrosslinking polyHIPE immobilized enzyme reactor for on-column protein digestion. - Highlights: • A reactor was prepared and used for enzyme immobilization and continuous on-column protein digestion. • The new polyHIPE IMER was quite suit for protein digestion with good properties. • On-column digestion revealed that the IMER was easy regenerated by HCl without any structure destruction.

  11. Online observation of emulsion polymerization by fluorescence technique

    CERN Document Server

    Rudschuck, S; Fuhrmann, J

    1999-01-01

    An online observation of local polarity via fluorescence spectroscopy was used to study the formation and growth of polymer particles during an emulsifier-free heterogeneous polymerization. The reaction mixture consisted of styrene dispersed in water and the polymerization was initiated by a macro-initiator (hydrolyzed propene-maleic acid copolymer with t-butyl perester groups). Pyrenyl probes were attached to the backbone of the initiator to analyze the heterogeneous reaction. The experimental results allow a clear distinction of different time regions during the heterogeneous polymerization. Information about the heating period, the latex formation, the particle growth and the final stage of the polymerization process (gel point) were obtained. (11 refs).

  12. Microstructure Control in the emulsion polymerization of fluorinated monomers

    Energy Technology Data Exchange (ETDEWEB)

    Apostolo, Marco [Ausimont R and D, Bollate (Italy); Morbidelli, Massimo [ETH Zentrum, Zuerich (Switzerland)

    1997-03-01

    In this paper a mathematical model able to evaluate the microstructure of fluorinated polymers is presented. The model uses the pseudo-homo polymerization approach to describe the kinetic evolution of polymerization reactions involving any number of monomer species. The molecular weight distribution is evaluated combining the classical leading moments method with a recently proposed model based on the numerical fractionation technique.

  13. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Deng, Bo; Li, Linfan; Jiang, Haiqing; Li, Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA).

  14. Reverse atom transfer radical polymerization of styrene in emulsion initiated by AIBN or V50

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kai; ZHANG Hongwen; LI Hongtu; WANG Jingyuan

    2005-01-01

    Reverse atom transfer radical polymerization of styrene was conducted in emulsion by using Cu(II)/2,2′- bipydine or Cu(II)/phen complexes, AIBN or V50 as the initiator, Brij-98 or OP-10 as the surfactant. The results of GPC showed that both polymerization processes exhibit living characters when using AIBN as the initiator. However, when V50 was used, the monomer conversion was fairly low and the whole polymerization was not controlled well. The measurement of particle size and its distribution told us that the latex particles were mean and stable when using Brij-98 as the surfactant.

  15. Incorporation of iodine in polymeric microparticles and emulsions

    Science.gov (United States)

    Kolontaeva, Olga A.; Khokhlova, Anastasia R.; Markina, Natalia E.; Markin, Alexey V.; Burmistrova, Natalia A.

    2016-04-01

    Application of different methods for formation of microcontainers containing iodine is proposed in this paper. Two types of microcontainers: microemulsions and microparticles have been investigated, conditions and methods for obtaining microcontainers were optimized. Microparticles were formed by layer-by-layer method with cores of calcium carbonate (CaCO3) as templates. Incorporation of complexes of iodine with polymers (chitosan, starch, polyvinyl alcohol) into core, shell and hollow capsules was investigated and loadings of microparticles with iodine were estimated. It was found that the complex of iodine with chitosan adsorbed at CaCO3 core is the most stable under physiological conditions and its value of loading can be 450 μg of I2 per 1 g of CaCO3. Moreover, chitosan was chosen as a ligand because of its biocompatibility and biodegradability as well as very low toxicity while its complex with iodine is very stable. A small amount of microparticles containing a iodine-chitosan complex can be used for prolonged release of iodine in the human body since iodine daily intake for adults is around 100 μg. "Oil-in-water" emulsions were prepared by ultrasonication of iodinated oils (sunflower and linseed) with sodium laurilsulfate (SLS) as surfactant solution. At optimal conditions, the homogenous emulsions remained stable for weeks, with total content of iodine in such emulsion being up to 1% (w/w). The oil:SLS ratio was equal to 1:10 (w/w), optimal duration and power of ultrasound exposure were 1.5 min and 7 W, correspondingly. Favorable application of iodized linseed oil for emulsion preparation with suitable oil microdroplets size was proved.

  16. STUDIES ON HIGH SOLID CONTENT AND STABLE EMULSIFIER—FREE EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    TangGuangliang; HaoGuangjie; 等

    1998-01-01

    In this article,AHPS(3-allyloxy-2-hydroxy-1-propanesulfonate salt) was synthesized to use in emulsifier-free emulsion polymerization of BA/BMA/MMA system for high solid content latexes.Storage stability,flow behavior of the latexes,morphology of the obtained latex particles,dynamic viscoelastic behavior,tensile strength and water resistance properties of the resulted copolymers were investigated.The experimental results show that with the addition of AHPS,stability of the emulsion is greatly improved that there appears no apparent precipitation during the polymerization and storage at room temperature for 6 months and at -10℃ for four months.Flow of the latexes follows the Bingham body laws,diameter of the latex particles is about 0.6μm,of which is larger than that of by conventional emulsion polymerization(0.12μm).In addition,not only water resistance of the copolymers obtained by emulsifier-free emulstion polymerization is greatly improved,but also tensile strength is obviously enhanced.

  17. Pigment encapsulation by emulsion polymerization using macro-RAFT copolymers.

    Science.gov (United States)

    Nguyen, Duc; Zondanos, Hollie S; Farrugia, Jason M; Serelis, Algirdas K; Such, Chris H; Hawkett, Brian S

    2008-03-04

    A new method is described, based on living amphipathic random macro-RAFT copolymers, which enables the efficient polymeric encapsulation of both inorganic and organic particulate materials via free-radical polymerization. The mechanism for this new approach is examined in the context of the polymer coating of zirconia- and alumina-coated titanium dioxide particles and its breadth of application demonstrated by the coating of organic phthalocyanine blue pigment particles. The particulate materials were first dispersed in water using a macro-RAFT copolymer as a stabilizer. Monomer and water-soluble initiator were then added to the system, and the monomer polymerized to form the coating. If nucleation of new polymer particles in the aqueous phase was to be avoided, it was found necessary to use a macro-RAFT copolymer that did not form micelles; within this constraint, a broad range of RAFT agents could be used. The macro-RAFT agents used in this work were found not to transfer competitively in the aqueous phase and therefore did not support growth of aqueous-phase polymer. Successful encapsulation of particles was demonstrated by TEM. The process described enables 100% of the particles to be encapsulated with greater than 95% of the polymer finishing up in the polymeric shells around the particles. Moreover, the coating reaction can be carried out at greater than 50% solids in many cases and avoids the agglomeration of particles during the coating step.

  18. Epoxy-acrylic core-shell particles by seeded emulsion polymerization.

    Science.gov (United States)

    Chen, Liang; Hong, Liang; Lin, Jui-Ching; Meyers, Greg; Harris, Joseph; Radler, Michael

    2016-07-01

    We developed a novel method for synthesizing epoxy-acrylic hybrid latexes. We first prepared an aqueous dispersion of high molecular weight solid epoxy prepolymers using a mechanical dispersion process at elevated temperatures, and we subsequently used the epoxy dispersion as a seed in the emulsion polymerization of acrylic monomers comprising methyl methacrylate (MMA) and methacrylic acid (MAA). Advanced analytical techniques, such as scanning transmission X-ray microscopy (STXM) and peak force tapping atomic force microscopy (PFT-AFM), have elucidated a unique core-shell morphology of the epoxy-acrylic hybrid particles. Moreover, the formation of the core-shell morphology in the seeded emulsion polymerization process is primarily attributed to kinetic trapping of the acrylic phase at the exterior of the epoxy particles. By this new method, we are able to design the epoxy and acrylic polymers in two separate steps, and we can potentially synthesize epoxy-acrylic hybrid latexes with a broad range of compositions.

  19. Coating individual single-walled carbon nanotubes with nylon 6,10 through emulsion polymerization.

    Science.gov (United States)

    Chen, Wei-Chiang; Wang, Randy K; Ziegler, Kirk J

    2009-08-01

    Solvent microenvironments are formed around individual single-walled carbon nanotubes (SWNTs) by mixing SWNT suspensions with water-immiscible organic solvents. These microenvironments are used to encapsulate the SWNTs with the monomer sebacoyl chloride. Hexamethylene diamine is then injected into the aqueous phase so the formation of nylon 6,10 is restricted to the interface between the microenvironment and water. This emulsion polymerization process results in uniform coatings of nylon 6,10 around individual SWNTs. The nylon-coated SWNTs remain dispersed in the aqueous phase and are highly luminescent at pH values ranging from 3 to 12. This emulsion polymerization method provides a general approach to coat nanotubes with various polymers.

  20. Preparation of poly (methyl methacrylate)/nanometer calcium carbonate composite by in-situ emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    史建明; 包永忠; 黄志明; 翁志学

    2004-01-01

    Methyl methacrylate (MMA) emulsion polymerization in the presence of nanometer calcium carbonate (nano-CaCO3) surface modified with (-methacryloxypropyltrimethoxysilane (MPTMS) was carried out to prepare poly (methyl methacrylate) (PMMA)/nano-CaCO3 composite. The reaction between nano-CaCO3 and MPTMS, and the grafting of PMMA onto nano-CaCO3 were confirmed by infrared spectrum. The grafting ratio and grafting efficiency of PMMA on nano-CaCO3 modified with MPTMS were much higher than that on nano-CaCO3 modified with stearic acid. The grafting ratio of PMMA increased as the weight ratio between MMA and nano-CaCO3 increased, while the grafting efficiency of PMMA decreased. Transmission electron micrograph showed that nano-CaCO3 covered with PMMA was formed by in-situ emulsion polymerization.

  1. Preparation of Emulsion Polymerization from Styrene Vinylpyrrolidone and Studying their Thermal Stability and Electrical Conductivity

    Directory of Open Access Journals (Sweden)

    Azza Mazrouaa

    2014-01-01

    Full Text Available Copolymer styrene and vinylpyrrolidone were prepared using different techniques. The emulsion polymerization technique was chosen as it gives the highest molecular weight with polymer particles in the nanorange. The polymer nanocomposites were prepared using Pickering emulsion polymerization stabilized by adding inorganic nanosized particles. Ag nanometal and nanometal oxides of CuO, ZnO and AgO were added into the copolymer for enhancing its thermal stability and electrical conductivity. The nanocomposite chemical structure was confirmed by using FTIR, 1HNMR spectroscopy and TEM. Transmission electron microscopy, TEM photos show that the copolymer particles are almost in the nanoscale region. The thermal stability (TGA of styrene-co-vinylpyrrolidone in the presence of the nanometal and nanometal oxides was slightly increased. The electrical conductivity of these nanocomposites using dc at different temperatures was measured. The data reveal that the nanocomposites are enhanced by adding the nanometal and nanometal oxides.

  2. Influence of Suspended Emulsion Polymerization Conditions on Particle Characteristics of Polyvinyl Chloride Resin

    Institute of Scientific and Technical Information of China (English)

    包永忠; 魏真理; 翁志学; 黄志明

    2003-01-01

    Suspended emulsion polymerization of vinyl chloride was carried out in a 5 L autoclave. The influence of agitation, polymerization conversion, dispersant and surfactant on the average particle size (PS) and particle size distribution (PSD), particle morphology and porosity of polyvinyl chloride (PVC) resin was investigated. It showed that the agitator had great influence on the smooth operation of polymerization, PS and PSD. The PS increased and PSD became narrow as polymerization conversion became high. The porosity decreased with the increase of conversion. A convenient choice of additives, both dispersants and non-ionic surfactants, allows one to adjust PS and PSD. The PS decreased with the addition of polyvinyl alcohol or hydroxypropyl methylcellulose dispersants,and increased with the addition of Span surfactants. The addition of dispersants or surfactants also affected the morphology and porosity of resin, and PVC resin with looser agglomeration and homogeneous distribution of primary particles was prepared.

  3. Preparation of semi-IPN(BA–VAc–VAE) by emulsion polymerization and its properties investigation

    Indian Academy of Sciences (India)

    Shi Luo; Zonghui Liu; Bailing Liu; Qi Liu

    2011-12-01

    A semi-interpenetrating polymer network (semi-IPN) combining vinyl acetate–ethylene (VAE) and butyl acrylate (BA), as well as vinyl acetate (VAc), was prepared through emulsion polymerization with the help of self-made dispersant and diethylene glycol diacrylate (DEGDA), the cross-linking agent. Both the dispersant and DEGDA had significant contribution on the preparation of semi-IPN(BA–VAc–VAE). And, the DEGDA had a strong influence on the conversion of polymerization system. The effects of emulsifiers and their amounts on the stability of obtained emulsions have been determined, and the best choices have been made after series experiments. The optical microscopy (OM), FTIR and DSC methods were adopted to characterize the structure and composition, morphology, and Tg of the prepared emulsions, respectively. Various comparisons have been made between the semi-IPN and VAE emulsions, and the experimental results indicated that the semi-IPN(BA–VAc–VAE) had been developed with improved properties in both water resistance and adhesion.

  4. INFLUENCES OF WATER-SOLUBLE CATIONIC MONOMERS ON THE POLYMERIZATION RATE IN THE INVERSE EMULSION

    Institute of Scientific and Technical Information of China (English)

    HOU Sijian; HA Runhua

    1996-01-01

    This investigation deals with the free radical polymerization both of (2-methacryloyloxyethyl) trimethyl ammonium chloride (QACEMA) and of diallyldimethyl ammonium chloride (DADMAC) in inverse emulsion. The influences of some factors, such as the concentration of monomers, initiator and emulsifier are discussed. The polymerization rate equations of above two monomers can be written as follows:Rp = k[M]1.21[I]0.82[E]0.57 (for QACEMA)Rp = k′[M]1.34[I]0.90[E]0.62 (for DADMAC)

  5. Emulsion Polymerization of Tung Oil-Based Latexes with Asolectin as a Biorenewable Surfactant

    Directory of Open Access Journals (Sweden)

    Ashley Johns

    2016-11-01

    Full Text Available Bio-based vesicles, with potential application in drug delivery and/or catalyst encapsulation, have been prepared by the free radical emulsion co-polymerization of tung oil, divinylbenzene (DVB, n-butyl methacrylate (BMA, and asolectin in a xylene/water mixture. The free radical polymerization was initiated by di-tert-butyl peroxide (DTBP at 100 °C in a convection oven. Molecular weights of approximately 11,000 Da were measured by Matrix-assisted Laser Desorption/Ionization-Time of Flight (Maldi-TOF for tung oil-asolectin copolymers, verifying that significant polymerization occurs under the cure conditions employed. The cure of the co-monomer mixture employed in this work was monitored by Dielectric Analysis (DEA, while changes in the Raman spectrum of all co-monomers before and after the cure, along with differential scanning calorimetry (DSC analysis, have been used to verify the need of a post-cure step and completion of the polymerization reaction. Scanning Transmission Electron Microscopy (STEM images of the emulsion after polymerization indicate that vesicles were formed, and vesicle size distribution of samples prepared with different amounts of tung oil were determined using a Zetasizer.

  6. Polymerization of vinyl acetate in bulk and emulsion by gamma irradiation

    Science.gov (United States)

    Mesquita, Andrea C.; Mori, Manoel N.; Andrade e Silva, Leonardo G.

    2004-09-01

    The vinyl acetate polymerization to produce poly(vinyl acetate) was carried out in bulk and emulsion using a 60Co gamma irradiator Gammacell-220 type. The irradiation was carried out in a dose rate of 5.25 and 5.30 kGy/h, respectively. The polymers obtained were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and gel permeation chromatography (GPC). Tests of density, hardness and Vicat softening temperature were carried out.

  7. Seeded emulsion polymerization as a powerful tool for the biofunctionalization of quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Habercorn, Lasse; Merkl, Jan-Philip; Kloust, Hauke Christian; Feld, Artur; Schmidtke, Christian; Wolter, Christopher; Janschel, Marcus [Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg (Germany); Ostermann, Johannes [Center for Applied Nanotechnology GmbH, Grindelallee 117, 20146 Hamburg (Germany); Weller, Horst [Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg (Germany); Center for Applied Nanotechnology GmbH, Grindelallee 117, 20146 Hamburg (Germany)

    2016-05-18

    With the polymer encapsulation of quantum dots via seeded emulsion polymerization we present a powerful tool for the preparation of fluorescent nanoparticles with an extraordinary stability in aqueous solution. The method of the seeded emulsion polymerization allows a straightforward and simple in situ functionalization of the polymer shell under preserving the optical properties of the quantum dots. These requirements are inevitable for the application of semiconductor nanoparticles as markers for biomedical applications. Polymer encapsulated quantum dots have shown only a marginal loss of quantum yields when they were exposed to copper(II)-ions. Under normal conditions the quantum dots were totally quenched in presence of copper(II)-ions. Furthermore, a broad range of in situ functionalized polymer-coated quantum dots were obtained by addition of functional monomers or surfactants like fluorescent dye molecules, antibodies or specific DNA aptamers. Furthermore the emulsion polymerization can be used to prepare multifunctional hybrid systems, combining different nanoparticles within one construct without any adverse effect of the properties of the starting materials.{sup 1,2}.

  8. Emulsion polymerization of vinyl acetate: Safe optimization of a hazardous complex process

    Energy Technology Data Exchange (ETDEWEB)

    Copelli, S.; Derudi, M. [Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica ' G. Natta' , via Mancinelli 7, 20131 Milano (Italy); Sempere, J.; Serra, E. [IQS Universitat Ramon Llull, Departament d' Enginyeria Quimica, Via Augusta 390, 08017 Barcelona (Spain); Lunghi, A.; Pasturenzi, C. [Stazione Sperimentale per i Combustibili, viale A. De Gasperi 3, 20097 S. Donato M.se (Italy); Rota, R., E-mail: renato.rota@polimi.it [Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica ' G. Natta' , via Mancinelli 7, 20131 Milano (Italy)

    2011-08-15

    Highlights: {yields} Polymerizations can be hazardous complex processes difficult to be safely optimized. {yields} We used a topological criterion to safely optimize an emulsion homopolymerization. {yields} The procedure was validated through experiments on vinyl acetate homopolymerization. {yields} The reported approach can be generalized to other complex hazardous reacting systems. - Abstract: Fast and exothermic discontinuous emulsion polymerization processes are particularly difficult to optimize from both safety and productivity point of view because of the occurrence of side undesired reactions (e.g. chain transfer to monomer, backbiting, propagation of tertiary radicals, termination by disproportion, etc.) and the hazards of boiling phenomena and stable foam formation under atmospheric pressure. Moreover, the relevant number of loading, heating and cooling steps, required before starting the monomer addition (that is, the desired reaction), makes a strict product quality reproducibility very difficult to obtain. Under these operating conditions, it is necessary to employ a suitable combined theoretical and experimental procedure able to detect the optimum process dosing time at both the laboratory and the industrial scale. In this work, it is shown how to use the topological criterion theory together with proper adiabatic calorimeter and RC1 experimental data to safely optimize the synthesis of polyvinyl acetate through the radical emulsion polymerization of vinyl acetate by the means of an indirectly cooled isoperibolic semibatch reactor.

  9. Formation and stability studies of multiple (w/o/w) emulsions prepared with newly synthesized rosin-based polymeric surfactants.

    Science.gov (United States)

    Dhanorkar, V T; Gogte, B B; Dorle, A K

    2001-07-01

    The multiple (water-in-oil-in-water, w/o/w) emulsions were prepared using newly synthesized rosin-based polymeric surfactants. The oil phase used was liquid paraffin. These emulsions were evaluated for stability by various methods: conductivity, viscosity, particle size, and visual inspection. The stability studies were carried out at 37 degrees C and 4 degrees C for 1 month. The multiple emulsion prepared with polymer 7 was found to be more stable compared to the emulsions prepared with polymer 2.

  10. Investigation of Four Different Laponite Clays as Stabilizers in Pickering Emulsion Polymerization.

    Science.gov (United States)

    Brunier, Barthélémy; Sheibat-Othman, Nida; Chniguir, Mehdi; Chevalier, Yves; Bourgeat-Lami, Elodie

    2016-06-21

    Clay-armored polymer particles were prepared by emulsion polymerization in the presence of Laponite platelets that adsorb at the surface of latex particles and act as stabilizers during the course of the polymerization. While Laponite RDS clay platelets are most often used, the choice of the type of clay still remains an open issue that is addressed in the present article. Four different grades of Laponite were investigated as stabilizers in the emulsion polymerization of styrene. First, the adsorption isotherms of the clays, on preformed polystyrene particles, were determined by ICP-AES analysis of the residual clay in the aqueous phase. Adsorption of clay depended on the type of clay at low concentrations corresponding to adsorption as a monolayer. Adsorption of clay particles as multilayers was observed for all the grades above a certain concentration under the considered ionic strength (mainly due to the initiator ionic species). The stabilization efficiency of these clays was investigated during the polymerization reaction (free of any other stabilizer). The clays did not have the same effect on stabilization, which was related to differences in their compositions and in their adsorption isotherms. The different grades led to different polymer particles sizes and therefore to different polymerization reaction rates. Laponite RDS and S482 gave similar results, ensuring the best stabilization efficiency and the fastest reaction rate; the number of particles increased as the clay concentration increased. Stabilization with Laponite XLS gave the same particles size and number as the latter two clays at low clay concentrations, but it reached an upper limit in the number of nucleated polymer particles at higher concentrations indicating a decrease of stabilization efficiency at high concentrations. Laponite JS did not ensure a sufficient stability of the polymer particles, as the polymerization results were comparable to a stabilizer-free polymerization system.

  11. Preparation of CO₂/N₂-triggered reversibly coagulatable and redispersible polyacrylate latexes by emulsion polymerization using a polymeric surfactant.

    Science.gov (United States)

    Zhang, Qi; Yu, Guoqiang; Wang, Wen-Jun; Li, Bo-Geng; Zhu, Shiping

    2012-05-29

    We report here a novel approach for making reversibly coagulatable and redispersible polyacrylate latexes by emulsion (co)polymerization of methyl methacrylate (MMA) using a polymeric surfactant, poly(2-(dimethylamino)ethyl methacrylate)(10) -block-poly(methyl methacrylate)(14) . The surfactant was protonated with HCl prior to use. The resulted PMMA latexes were readily coagulated with trace amount of caustic soda. The coagulated latex particles, after washing with deionized water, could be redispersed into fresh water to form stable latexes again by CO(2) bubbling with ultrasonication. The recovered latexes could then be coagulated by N(2) bubbling with gentle heating. These coagulation and redispersion processes were repeatable by the CO(2) /N(2) bubbling.

  12. Synthesis of polyanthranilic acid–Au nanocomposites by emulsion polymerization: development of dopamine sensor

    Indian Academy of Sciences (India)

    Bhavana Gupta; Ambrose Melvin; Rajiv Prakash

    2014-10-01

    Polyanthranilic acid (PANA) and polyanthranilic acid–gold (PANA–Au) nanocomposites have been synthesized through emulsion polymerization technique. Use of gold chloride as an oxidant for anthranilic acid not only provides a new route for chemical synthesis of PANA, but also explores a facile method for the formation of nanocomposites. Emulsion polymerization helps in slowing down kinetics of polymerization in comparison to one-phase polymerization and thereby induces formation of monodispersed, both pure and Au nanoparticles, embedded PANA sphere. Reaction progress of nanocomposite formation is studied by UV–Vis spectroscopy for 0–24 h. PANA–Au nanocomposites are characterized by SEM, equipped with EDS, TGA, FT–IR, XRD and electrochemical techniques. XRD of nanocomposites depicts the amorphous nature of polymer and crystalline nature of Au with crystallite size of ∼ 24 nm. Differential pulse voltammetry has shown the electro-active nature of PANA. The nanocomposites with improved thermal properties show good dispersion in common organic solvents, and it can be explored for application in interference-free dopamine sensors with sensitivity 12.5 A/mM. Acidic group (–COOH) on the polymer makes the sensor free from ascorbic acid interference.

  13. Preparation of Self-crosslinked Fluorocarbon Polymer Emulsion with Core-shell Structure by the Method of Soap-free Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    CHEN Lijun; SHI Hongxin; XIANG Juping; WU Hongke

    2009-01-01

    Using methyl methacrylate(MMA),butyl acrylate(BA)and hexafluorobutyl acry-late(HFBA)as main raw materials,we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free emulsion polymerization when the conception of particle design and polymer morphology was adopted.Moreover,the influence of mole ratio of BA to MAA,pH value on the oligomer was studied.And the effects of the added amount of oligomer,self-crosslinked monomer and HFBA,mass ratio of BA to MMA,reaction temperature and the initiator on the polymerization technology and the performance of the product,were investigated and optimized.The structure and performance of the fluorocarbon polymer emulsion were characterized and tested with FTIR,TEM, MFT and contact angle and water absorption of the latex film.The experimental results show that the optimal conditions for preparing fluorocarbon polymer emulsion are as follows:for preparing the oligomer,mol ratio of BA to MAA is equal to 1.0:1.60,and pH value is controlled within the range of 8.0 and 9.0;for preparing fluorocarbon polymer emulsion,the added amount of oligmer[P(BA/MANa)] is 6%;mass ratio of BA to MMA is 40:60;the added amount of self-crosslinked monomer is 2%,the added amount of HFBA is 15%;reaction temperature is 80℃;the mixture of potassium persulfate and sodium bisulfite is used as the initiator.The film-forming stability of the fluorocarbon polymer emul-sion and the performance of the latex film,which is prepared with the soap-free emulsion polymeri-zation,are better than that prepared with the conventional emulsion polymerization.

  14. Reactivity of vegetable oil macromonomers in thiol-ene, cationic, and emulsion polymerizations

    Science.gov (United States)

    Black, Micah Stephen

    Vegetable oils were, and continue, to be a mainstay in unsaturated polyester ("alkyd") technology. Our endeavor is to use vegetable oil-based polymers in environmentally-friendly coatings. The role of vegetable oil cis-unsaturation has not been fully explored in polymers. To that end, vegetable oil macromonomers (VOMMs) in three different systems were investigated to determine the involvement of cis-unsaturation in chain transfer, auto-oxidation, and copolymerization reactions. VOMMs were incorporated into UV curable thiol-ene coatings, UV cationic coatings, and acrylic solution copolymers and fundamental studies were conducted to determine how and to what extent cis-unsaturation contributes to film performance properties. In thiol-ene UV curable coatings, cis-unsaturation was involved in the initial curing reaction and to lesser degrees, in postcure crosslinking. Its behavior was determined to be dependent on the ene component. Thiol-ene photopolymerization yielded homogeneous networks but formulations containing VOMMs exhibited greater heterogeneity due to non-uniformity in the VOMM chemical structures, and the concurrent reactions occurring during thiol-ene photopolymerization and "dark cure". Partially epoxidized soybean oil was synthesized to contain varying levels of residual cis-unsaturation. Cationic photopolymerization of partially epoxidized soybean oil yielded lightly crosslinked films, but the influence of free radical decomposition byproducts has not been fully investigated. The low involvement of the cis-unsaturation in photopolymerization was attributed to its low reactivity and/or radical combination with antioxidants and molecular oxygen dissolved in the films. When used in emulsion polymerization, VOMMs lower the minimum filming temperature during coalescence and increase the Tg after application via auto-oxidation. Free radical polymerization of VOMMs is accompanied by chain transfer reactions between polymer radicals and VOMMs that reduces

  15. Facile fabrication of Pickering emulsion polymerized polystyrene/laponite composite nanoparticles and their electrorheology.

    Science.gov (United States)

    Kim, Young Jae; Liu, Ying Dan; Choi, Hyoung Jin; Park, Soo-Jin

    2013-03-15

    Polystyrene (PS)/laponite composite nanoparticles were fabricated using a surfactant-free Pickering emulsion polymerization method, in which emulsions of styrene dispersed in water were stabilized by hydrophilic laponite modified with cetyltrimethylammonium bromide. The PS/laponite nanoparticles, of which their surface was covered compactly by laponite clay platelets, were observed by scanning electron microscopy. Fourier-transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis confirmed their chemical composition, crystallographic structure, and thermal properties and weight loss percentage of the laponite located on the surface of the PS particle, respectively. When an external electrical field was applied, the chain-like structure of the laponite coated nano-sized PS particle exhibiting electrorheological characteristics was observed by optical microscopy. The electrorheological performance of the bulk properties was also examined using a rotational rheometer equipped with a high voltage generator.

  16. Nanoscale trifunctional bovine hemoglobin for fabricating molecularly imprinted polydopamine via Pickering emulsions-hydrogels polymerization.

    Science.gov (United States)

    Sun, Yanhua; Zhong, Shian

    2017-07-29

    In this work, a novel strategy was developed for the selective recognition of protein based on oil-in-water Pickering emulsions-hydrogels polymerization and interfacial imprinting method. For the first time, nanoscale trifunctional bovine hemoglobin (BHb) played three roles simultaneously during the process, including emulsifier, template protein and sacrificial material for further exposing recognition sites. Prior to acting as stabilizers, bovine hemoglobin colloidal particles (BCPs) were firstly prepared by acidification and heat denaturation. Then the BCPs acted as "surfactant" to stabilize the Pickering emulsions composed of functional monomers in the water phase. After dopamine polymerized, the template proteins were removed, forming the BHb imprinted cavities on the surface of the polymeric materials. During this process, the interfacial BCPs also fell off, leaving more imprinted cavities exposed. FT-IR spectroscopy confirmed that BCPs were completely removed from the synthesized imprinted materials. The interconnected macropores structures of the materials encouraged nearly all of the rebinding sites located on its surface. Thus the prepared Hydro-MIPs exhibited rapid and selective recognition toward BHb. Owing to the hierarchical porous structure, the BHb imprinted polymers based on Pickering emulsions-hydrogels (Hydro-MIPs) possessed enhanced rebinding kinetics, and the maximum rebinding capacity is 449mgg(-1), 3.97 times higher than that of the non-imprinted polymers (Hydro-NIPs). Besides these, the regeneration ability test suggested that the Hydro-MIPs could be used repeatedly without distinct loss in adsorption capacity. Overall, the combination of high selectivity, good mass transfer efficiency, easy preparation and trifunctional BHb provide a new insight into bioseparation and proteomics research in biological area. Copyright © 2017. Published by Elsevier B.V.

  17. Emulsion Polymerization of Etyl Acrylate: The Effect of Surfactant, Initiator Concentration and PolymerizationTechnique on Particle Size Distribution

    Directory of Open Access Journals (Sweden)

    Nitri Arinda

    2009-04-01

    Full Text Available Emulsion polymerization was conducted using ethyl acrylate monomer. Theeffect of sodium lauryl sulfate concentration, ammonium persulfate concentration, the various of polymerizationtechniques and feeding time to the conversion, particle size and its distribution were observed. The purpose of thisresearch is to obtain the optimum condition of ethyl acrylate homopolymer with particle size around 100 nm, to get theparticle size distribution monodisperse and to get solid content value of the experiment closed to its theoretical value.The optimum condition then could be applied in shell polymerization of core-shell polymers. The results of the researchshowed that semicontinuous technique obtained optimum sodium lauryl sulfate concentration at 20 CMC (criticalmicelle concentration and ammonium persulfate concentration is 3%. By using batch technique that the biggestparticle size is 123 nm with conversion 95.8% and monodisperse. The shorter of feeding time the more monomer ofethyl acrylate being polymerized, it is showed by the higher conversion up to 94.4% and the bigger particle size is107.9 nm.

  18. Rheological and droplet size analysis of W/O/W multiple emulsions containing low concentrations of polymeric emulsifiers

    OpenAIRE

    Vasiljević, Dragana D.; JELENA V. PAROJČIĆ; Primorac, Marija M.; Vuleta, Gordana M.

    2009-01-01

    Multiple emulsions are complex dispersion systems which have many potential applications in pharmaceutics, cosmetics and the food industry. In practice, however, significant problems may arise because of their thermodynamic instability. In this study, W/O/W multiple emulsion systems containing low concentration levels of lipophilic polymeric primary emulsifiers cetyl dimethicone copolyol and PEG–30 dipolyhydroxystearate were evaluated. The concentrations of the primary emulsifiers were set at...

  19. SYNTHESIS OF BOWL-LIKE PARTICLES BY EMULSION POLYMERIZATION AND RELEASE BEHAVIOR OF SOLVENT FROM THE PARTICLES

    Institute of Scientific and Technical Information of China (English)

    HAO Guangjie; SHEN Xiaoyi; LIANG Zhiwu; GUO Tianying; ZHANG Banghua

    2004-01-01

    Poly(styrene-glycidyl methacrylate) particles having bowl-shaped hollow structures were synthesized by swollen seed emulsion polymerization. The PS emulsion synthesized through soap-free emulsion polymerization was swollen by toluene, and then the mixture of second monomers was added under polymerization condition. So a thin shell of poly(styrene-glycidyl methacrylate) cross-linked by triethylene glycol diacrylate was formed around the swollen PS particle. The bowl-shaped particles were obtained after the collapsing of the thin shell when the toluene emanated from the particles, but the shapes were effected by the degrees of cross-linking. The shape of the particles was observed by SEM. The release behavior of solvent from the particles was examined by TG.

  20. MMA/DVB emulsion surface graft polymerization initiated by UV light.

    Science.gov (United States)

    Wang, Yongxin; Yang, Wantai

    2004-07-20

    Methyl methacrylate/1,2-divinylbenzene (MMA/DVB) in an opaque emulsion were successfully grafted onto the surface of polymeric substrate under the irradiation of UV light with benzophenone (BP) as a photoinitiator that was previously coated on the substrate surface. Monomer conversion, grafting efficiency, and grafting yields were determined by the gravimetric method. ATR-IR, AFM, and TEM were used to characterize the surface composition, to observe the topography of the grafted substrates, and to view inter-film colloid particles formed by cross-linking. The results reveal that, with the opaque MMA/DVB emulsion system and CPP film as substrate, the monomer conversion is in the range of 15-55%, the grafting efficiency is about 80%, the grafting yield reaches 5%, and the thickness of the graft layer can be controlled in the range 0.09-1.5 microm. Images of AFM show that the graft layer is piled up by nanoparticles (about 30-50 nm in diameter), which are linked together and tied to the substrate surface with covalent bonds. A possible model of surface graft polymerization including surface initiating, nucleation, and shish kebab growing is put forward to interpreting the above results.

  1. An easily regenerable enzyme reactor prepared from polymerized high internal phase emulsions.

    Science.gov (United States)

    Ruan, Guihua; Wu, Zhenwei; Huang, Yipeng; Wei, Meiping; Su, Rihui; Du, Fuyou

    2016-04-22

    A large-scale high-efficient enzyme reactor based on polymerized high internal phase emulsion monolith (polyHIPE) was prepared. First, a porous cross-linked polyHIPE monolith was prepared by in-situ thermal polymerization of a high internal phase emulsion containing styrene, divinylbenzene and polyglutaraldehyde. The enzyme of TPCK-Trypsin was then immobilized on the monolithic polyHIPE. The performance of the resultant enzyme reactor was assessed according to the conversion ability of Nα-benzoyl-l-arginine ethyl ester to Nα-benzoyl-l-arginine, and the protein digestibility of bovine serum albumin (BSA) and cytochrome (Cyt-C). The results showed that the prepared enzyme reactor exhibited high enzyme immobilization efficiency and fast and easy-control protein digestibility. BSA and Cyt-C could be digested in 10 min with sequence coverage of 59% and 78%, respectively. The peptides and residual protein could be easily rinsed out from reactor and the reactor could be regenerated easily with 4 M HCl without any structure destruction. Properties of multiple interconnected chambers with good permeability, fast digestion facility and easily reproducibility indicated that the polyHIPE enzyme reactor was a good selector potentially applied in proteomics and catalysis areas.

  2. Capillary-assisted fabrication of biconcave polymeric microlenses from microfluidic ternary emulsion droplets.

    Science.gov (United States)

    Nisisako, Takasi; Ando, Takuya; Hatsuzawa, Takeshi

    2014-12-29

    In this study, a simple capillary-based approach for producing biconcave polymeric microlenses with uniform size and shape from ternary emulsion droplets is presented. Monodisperse ternary emulsion droplets (0.6-4.0 nL) are produced which contain a photocurable segment of an acrylate monomer and two non-curable segments of silicone oil (SO) by using a microfluidic sheath-flowing droplet generator on a glass chip. The curvature radius of the interfaces separating the droplet segments, as well as the droplet size, and production rate can be flexibly varied by changing the flow conditions of the organic and aqueous phases. Subsequently, off-chip suspension photopolymerization yields non-spherical polymeric microparticles with two spherical concave surfaces templated by two SO segments at random positions. By ultraviolet light irradiation of ternary droplets with two SO segments trapped by the interior wall of a cylindrical microcapillary (internal diameter: 130 μm), biconcave microlenses can be produced with two spherical concave surfaces with a common lens axis. The produced lenses are suitable for use as optical diverging lenses.

  3. Core-corona PSt/P(BA-AA) composite particles by two-stage emulsion polymerization

    Science.gov (United States)

    Xie, Delong; Ren, Xiaolin; Zhang, Xinya; Liao, Shijun

    2016-03-01

    Raspberry-shaped composite particles with polystyrene (PSt) as core and poly(n-butyl acrylate-co-acrylic acid) (P(BA-AA)) as corona were synthesized via emulsion polymerization. The random copolymer, P(BA-AA), was pre-prepared and used as a polymeric surfactant, its emulsifying properties adjusted by changing the mass ratio of BA and AA. The morphology of the resulting core-corona composite particles, P(St/P(BA-AA)), could be regulated and controlled by varying the concentrations of P(BA-AA) or the mass ratio of BA:AA in P(BA-AA). The experimental results indicate that 3.0-6.0 wt% of P(BA-AA) is required to obtain stable composite emulsions, and P(BA-AA) with a mass ratio of BA:AA = 1:2 is able to generate distinct core-corona structures. A mechanism of composite particle formation is proposed based on the high affinity between the PSt core and the hydrophobic segments of P(BA-A). The regular morphology of the colloidal film is expected to facilitate potential application of core-corona particles in the field of light scattering. Furthermore, the diversity of core-corona particles can be expanded by replacing P(BA-AA) corona particles with other amphiphilic particles.

  4. Emulsion polymerization of vinyl acetate: safe optimization of a hazardous complex process.

    Science.gov (United States)

    Copelli, S; Derudi, M; Sempere, J; Serra, E; Lunghi, A; Pasturenzi, C; Rota, R

    2011-08-15

    Fast and exothermic discontinuous emulsion polymerization processes are particularly difficult to optimize from both safety and productivity point of view because of the occurrence of side undesired reactions (e.g. chain transfer to monomer, backbiting, propagation of tertiary radicals, termination by disproportion, etc.) and the hazards of boiling phenomena and stable foam formation under atmospheric pressure. Moreover, the relevant number of loading, heating and cooling steps, required before starting the monomer addition (that is, the desired reaction), makes a strict product quality reproducibility very difficult to obtain. Under these operating conditions, it is necessary to employ a suitable combined theoretical and experimental procedure able to detect the optimum process dosing time at both the laboratory and the industrial scale. In this work, it is shown how to use the topological criterion theory together with proper adiabatic calorimeter and RC1 experimental data to safely optimize the synthesis of polyvinyl acetate through the radical emulsion polymerization of vinyl acetate by the means of an indirectly cooled isoperibolic semibatch reactor.

  5. Stable modification of PDMS surface properties by plasma polymerization: application to the formation of double emulsions in microfluidic systems.

    Science.gov (United States)

    Barbier, Valessa; Tatoulian, Michaël; Li, Hong; Arefi-Khonsari, Farzaneh; Ajdari, Armand; Tabeling, Patrick

    2006-06-06

    We describe a method based on plasma polymerization for the modification and control of the surface properties of poly(dimethylsiloxane) (PDMS) surfaces. By depositing plasma polymerized acrylic acid coatings on PDMS, we succeeded to fabricate stable (several days) hydrophilic and patterned hydrophobic/hydrophilic surfaces. We used this approach to generate direct and (for the first time in this material) double emulsions in PDMS microchannels.

  6. Heterogeneous polymerizations in supercritical carbon dioxide continuous phases

    Energy Technology Data Exchange (ETDEWEB)

    DeSimone, J.M.; Maury, E.E.; Combes, J.R.; Menceloglu, Y.Z. [Univ. of North Carolina, Chapel Hill, NC (United States)

    1993-12-31

    Heterogeneous emulsion polymerizations are important industrial methods for the synthesis of various polymeric materials. These processes generally use water as the dispersing medium. The authors propose to utilize carbon dioxide as the dispersing medium which would make the polymer recovery easier and would circumvent the contamination of water. In CO{sub 2} - based emulsion process one can have either a hydrophilic dispersed phase (hydrophilic monomer) or a hydrophobic dispersed phase (hydrophobic monomer). The surfactant has to be designed to partition itself at the CO{sub 2} - monomer/polymer interface and the initiator has to be soluble in the dispersing medium. The design of the initiator and graft copolymer surfactants will be presented. One example of a graft copolymer is a copolymer of poly(ethylene oxide) macromonomer synthesized by living anionic polymerization and a fluoroacrylate monomer resulting in a graft copolymer having hydrophilic grafts and a {open_quotes}CO{sub 2}-philic{close_quotes} backbone (due to the fluorine chains). The phase behavior of these surfactants will be discussed at the meeting.

  7. Role of nanoclay shape and surface characteristics on the morphology and thermal properties of polystyrene nanocomposites synthesized via emulsion polymerization

    CSIR Research Space (South Africa)

    Greesh, N

    2013-10-01

    Full Text Available This work evaluates the role of the surface properties and shape of clay type on the morphology, thermal, and thermo-mechanical properties of the polystyrene (PS)/clay nanocomposites prepared via free-radical emulsion polymerization. Attapulgite...

  8. MORPHOLOGY EVOLUTION OF POLY(St-co-BuA)/SILICA NANOCOMPOSITE PARTICLES SYNTHESIZED BY EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Hua Li; Shu-xue Zhou; Bo You; Li-min Wu

    2006-01-01

    Poly(St-co-BuA)/silica nanocomposite latexes were synthesized via conventional emulsion polymerization in the presence of 3-(trimethoxysilyl)propyl methacrylate modified colloidal nano-silica. The effects of surface property, particle size and content of colloidal nano-silica as well as the concentrations of monomer and surfactant on the morphology of nanocomposite latex particles were investigated by transmission electron microscope (TEM) and scanning electron microscope (SEM) in detail. Various interesting morphologies such as grape-like, Chinese gooseberry-like, pomegranate-like and normal core-shell structures were observed. Droplet nucleation mechanism competing with micelle nucleation mechanism was proposed to explain the morphological evolution of the nanocomposite particles.

  9. Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

    2016-10-15

    Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

  10. Preparation of poly(Urethane-urea) nanoparticles containing acai oil by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Valerio, Alexsandra; Araujo, Pedro H.H.; Sayer, Claudia, E-mail: csayer@enq.ufsc.br [Universidade Federal de Santa catarina (UFSC), SC (Brazil). Dept. de Quimica e Engenharia de Alimentos

    2013-07-01

    Polyurethane nanoparticles (NPs) are promising candidates for the controlled and targeted delivery of therapeutics in a variety of biomedical applications. In this work, a report is made of NPs produced by mini emulsion polymerization with isophorone diisocyanate (IPDI) and castor oil, glycerol, and poly(ethylene glycol) (PEG) with molar masses 400 and 1000 as monomers and Tween 80, Span 80 and Lutensol AT 25 as surfactant and acai oil as costabilizer. Stable dispersions with sizes between 100 - 500 nm were achieved. The effects from polyol, types and concentration of surfactant and reaction temperature on the size of the NPs and weight average molar mass were evaluated. Morphological characterization was accomplished using images from Transmission Electron Microscopy (TEM) and Scanning Electron Microscope (SEM). (author)

  11. Rheological Properties in Aqueous Solution for Hydrophobically Modified Polyacrylamides Prepared in Inverse Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Shirley Carro

    2017-01-01

    Full Text Available Inverse emulsion polymerization technique was employed to synthesize hydrophobically modified polyacrylamide polymers with hydrophobe contents near to feed composition. Three different structures were obtained: multisticker, telechelic, and combined. N-Dimethyl-acrylamide (DMAM, n-dodecylacrylamide (DAM, and n-hexadecylacrylamide (HDAM were used as hydrophobic comonomers. The effect of the hydrophobe length of comonomer, the initial monomer, and surfactant concentrations on shear viscosity was studied. Results show that the molecular weight of copolymer increases with initial monomer concentration and by increasing emulsifier concentration it remained almost constant. Shear viscosity measurements results show that the length of the hydrophobic comonomer augments the hydrophobic interactions causing an increase in viscosity and that the polymer thickening ability is higher for combined polymers.

  12. Sequence-controlled methacrylic multiblock copolymers via sulfur-free RAFT emulsion polymerization

    Science.gov (United States)

    Engelis, Nikolaos G.; Anastasaki, Athina; Nurumbetov, Gabit; Truong, Nghia P.; Nikolaou, Vasiliki; Shegiwal, Ataulla; Whittaker, Michael R.; Davis, Thomas P.; Haddleton, David M.

    2017-02-01

    Translating the precise monomer sequence control achieved in nature over macromolecular structure (for example, DNA) to whole synthetic systems has been limited due to the lack of efficient synthetic methodologies. So far, chemists have only been able to synthesize monomer sequence-controlled macromolecules by means of complex, time-consuming and iterative chemical strategies such as solid-state Merrifield-type approaches or molecularly dissolved solution-phase systems. Here, we report a rapid and quantitative synthesis of sequence-controlled multiblock polymers in discrete stable nanoscale compartments via an emulsion polymerization approach in which a vinyl-terminated macromolecule is used as an efficient chain-transfer agent. This approach is environmentally friendly, fully translatable to industry and thus represents a significant advance in the development of complex macromolecule synthesis, where a high level of molecular precision or monomer sequence control confers potential for molecular targeting, recognition and biocatalysis, as well as molecular information storage.

  13. Emulsion polymerization of polystyrene-co-acrylic acid with Cu2O incorporation

    Science.gov (United States)

    Fahmiati, Sri; Harmami, Sri Budi; Meliana, Yenny; Haryono, Agus

    2017-01-01

    In this research, poly(styrene-co-acrylic acid-Cu) was prepared via emulsion polymerization.Cu contents were varied as 10%, 15% and 20% and mol ratio of styrene to acrylic acid as 1:1 and 2:1. Structure and surface of poly(styrene-co-acrylic acid-Cu) were characterized by FTIR (Fourier Transformed Infra Red), NMR (Nuclear Magnetic Resonance), and SEM/EDX (Scanning Electron Microcope/ Energy Dispersive X-Ray) spectroscopy. The NMR spectra showed that the polymer was formed, however FTIR spectra showed that there were still unreacted monomers. SEM-EDX confirmed that copper (Cu) was dispersed uniformly on poly(styrene-co-acrylic acid-Cu) matrix.

  14. Anisotropic nanoparticles with controllable morphologies from non-cross-linked seeded emulsion polymerization.

    Science.gov (United States)

    Niu, Qun; Pan, Mingwang; Yuan, Jinfeng; Liu, Xiao; Wang, Xiaomei; Yu, Haifeng

    2013-09-01

    A simple and elegant approach to fabricate anisotropic P(VC-co-AAEM)/PS nanoparticles with controllable morphologies via emulsifier-free seeded emulsion polymerization is presented. Non-cross-linked P(VC-co-AAEM) seeds with hydrophilic surface are first synthesized through copolymerization of vinyl chloride (VC) and acetoacetoxyethyl methacrylate (AAEM), which are used to prepare P(VC-co-AAEM)/PS NPs with multiple bulges by SEP of styrene. Electron microscopy observation indicates that the content of AAEM in seeds is crucial to control the phase separation and morphology of the composite NPs. Moreover, the thermodynamic immiscibility between PVC and PS is the driving force for the formation of PS bulges onto the P(VC-co-AAEM) seeds. The resultant anisotropic NPs with non-cross-linked feature may promisingly serve as compatibilizers for further polymer processing. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Rheological and droplet size analysis of W/O/W multiple emulsions containing low concentrations of polymeric emulsifiers

    Directory of Open Access Journals (Sweden)

    DRAGANA D. VASILJEVIĆ

    2009-07-01

    Full Text Available Multiple emulsions are complex dispersion systems which have many potential applications in pharmaceutics, cosmetics and the food industry. In practice, however, significant problems may arise because of their thermodynamic instability. In this study, W/O/W multiple emulsion systems containing low concentration levels of lipophilic polymeric primary emulsifiers cetyl dimethicone copolyol and PEG–30 dipolyhydroxystearate were evaluated. The concentrations of the primary emulsifiers were set at 1.6 and 2.4 % w/w in the final emulsions. Rheological and droplet size analysis of the investigated samples showed that the type and concentration of the primary lipophilic polymeric emulsifier markedly affected the characteristics of the multiple emulsions. The multiple emulsion prepared with 2.4 % w/w PEG–30 dipolyhydroxystearate as the primary emulsifier exhibited the highest apparent viscosity, yield stress and elastic modulus values, as well as the smallest droplet size. Furthermore, these parameters remained relatively constant over the study period, confirming the high stability of the investigated sample. The results obtained indicate that the changes observed in the investigated samples over time could be attributed to the swelling/breakdown mechanism of the multiple droplets. Such changes could be adequately monitored by rheological and droplet size analysis.

  16. PARTICLE MORPHOLOGY OF POLY(VINYL CHLORIDE) RESIN PREPARED BY SUSPENDED EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Yong-zhong Bao; Zhen-li Wei; Zhi-xue Weng; Zhi-ming Huang

    2003-01-01

    Suspended emulsion polymerization was used to prepare poly(vinyl chloride) (PVC) resin. Fine PVC particles were formed at low polymerization conversions. The amount of fine particles decreases as conversion increases and disappears at conversions greater than 30%. Scanning electron micrographs show that PVC grains are composed of loosely coalesced primary particles, especially for PVC resins prepared in the presence of poly(vinyl alcohol) dispersant. The size of primary particles increases and porosity decreases with the increase of conversion. In view of the particle features of PVC resin, a particle formation mechanism including the formation of primary particles and grains is proposed. The formation process of primary particles includes the formation of particle nuclei, coalescence of particle nuclei to form primary particles,and growth of primary particles. PVC grains are formed by the coagulation of primary particles. The loose coalescence of primary particles is caused by the colloidal stability of primary particles and the low swelling degree of vinyl chloride in the primary particles.

  17. NONCONVENTIONAL EMULSION POLYMERIZATION OF ACRYLONITRILE CATALYZED BY in situ METAL COMPLEX

    Institute of Scientific and Technical Information of China (English)

    Bijayashree Samal; Prafulla K.Sahoo

    2007-01-01

    Nano-sized polyacrylonitrile (PAN) particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier.The emulsion polymerization was studied at varying concentrations of the initiator,monomer,complex and solvent over a temperature range of 30-70℃.The overall activation energy(Ea,49.79 kJ/mol),energy of dissociation of initiator(Ed,82.68kJ/mol),number of micelles(0.163 × 1018)and the viscosity average molecular weight of the polymer were computed.The distribution of particle sizes was determined by transmission electron microscopy(TEM).It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order.The average diameters of PAN nano particles,obtained by TEM,were in the range of 50-150 nm at the maximum conversion.The experimental particle size was mainly dependent on the concentration of the complex and temperature.

  18. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  19. Superparamagnetic polymer emulsion particles from a soap-free seeded emulsion polymerization and their application for lipase immobilization.

    Science.gov (United States)

    Cui, Yanjun; Chen, Xia; Li, Yanfeng; Liu, Xiao; Lei, Lin; Zhang, Yakui; Qian, Jiayu

    2014-01-01

    Using emulsion copolymer of styrene (St), glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) as seed latexes, the superparamagnetic polymer emulsion particles were prepared by seeded emulsion copolymerization of butyl methacrylate (BMA), vinyl acetate (VAc) and ethylene glycol dimethacrylate in the presence of the seed latexes and superparamagnetic Fe3O4/SiOx nanoparticles (or Fe3O4-APTS nanoparticles) through a two-step process, without addition of any emulsifier. The magnetic emulsion particles named P(St-GMA-HEMA)/P(BMA-VAc) were characterized by transmission electron microscope and vibrating sample magnetometry. The results showed that the magnetic emulsion particles held a structure with a thinner shell (around 100 nm) and a bigger cavity (around 200 nm), and possessed a certain level of magnetic response. The resulting magnetic emulsion particles were employed in the immobilization of lipase by two strategies to immobilized lipase onto the resulting magnetic composites directly (S-1) or using glutaraldehyde as a coupling agent (S-2), thus, experimental data showed that the thermal stability and reusability of immobilized lipase based on S-2 were higher than that of S-1.

  20. Physical and material properties of an emulsion-based lipstick produced via a continuous process.

    Science.gov (United States)

    Beri, A; Pichot, R; Norton, I T

    2014-04-01

    Water-in-oil emulsions in lipsticks could have the potential to improve moisturizing properties and deliver hydrophilic molecules to the lips. The aim of this work was to investigate the effect of a continuous process (scraped surface heat exchanger (SSHE) and pin stirrer (PS)) on the physical and material properties of an emulsion-based lipstick by altering the processing conditions of both the SSHE and PS. Emulsion formation was achieved using a SSHE and PS. Emulsions were analysed using nuclear magnetic resonance restricted diffusion (droplet size), texture analysis and rheology (mechanical properties). Results showed that a higher impeller rotational velocity (IRV) (1500 r.p.m.) and a lower exit temperature (52°C) produce the smallest droplets (~ 4 μm), due to greater disruptive forces and a higher viscosity of the continuous phase. The addition of a PS reduces the droplet size (14-6 μm) if the SSHE has a low IRV (500 r.p.m.), due to greater droplet disruption as the emulsion passes through the PS unit. Results also show that if the jacket temperature of a SSHE is 65°C, so that crystallization occurs in both process and post-production, droplets can be integrated into the network resulting in a stiffer wax network (G' - 0.12, in comparison to 0.02 MPa). This is due to small crystals creating a shell around water droplets which can form connections with the continuous network forming a structured network. The addition of a pin stirrer can disrupt a formed network reducing the stiffness of the emulsion (0.3-0.05 MPa). This work suggests the potential use of a continuous process in producing an emulsion-based lipstick, particularly when wax crystals are produced in the process. Future work should consider the moisturizing or lubricating properties of wax continuous emulsions and the release of hydrophilic compounds from the aqueous phase.

  1. Synthesis and characterization of PMMA/Al2O3 composite particles by in situ emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    Hui Liu; Hongqi Ye; Tianquan Lin; Tao Zhou

    2008-01-01

    In order to improve its dispersibility, superfine alumina (Al2O3) was encapsulated with poly (methyl methacrylate) (PMMA) by in situ emulsion polymerization. It was found that only when the concentration of sodium dodecyl sulfate (SDS) was much higher than its critical micelle concentration, could PMMA/Al2O3 composite particles with high percentage of grafting (PG) be prepared. The same results were obtained between the experimental and stoichiometric amounts of tris (dodecylbenzenesulfonate) isopropoxide (NDZ), indicating that single-molecule-layer adsorption had taken place between NDZ and Al2O3. Analysis using FTIR. TEM and XPS showed that PMMA/Al2O3 composite particles with core-shell structure had been successfully synthesized by in sire emulsion polymerization. Compared to Al2O3, thermal stability and dispersibility of the composite particles showed marked improvement.

  2. Preparation of poly (methyl methacrylate)/nanometer calcium carbonate composite by in-situ emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    史建明; 包永忠; 黄志明; 翁志学

    2004-01-01

    Methyl methacrylate (MMA) emulsion polymerization in the presence of nanometer calcium carbonate(nano-CaCO3) surface modified with γ-methacryloxypropyltrimethoxysilane (MPTMS) was carried out to prepare poly (methyl methacrylate) (PMMA)/nano-CaCO3 composite. The reaction between nano-CaCO3 and MPTMS, and the grafting of PMMA onto nano-CaCO3 were confirmed by infrared spectrum. The grafting ratio and grafting efficiency of PMMA on nano-CaCO3 modified with MPTMS were much higher than that on nano-CaCO3 modified with stearic acid. The grafting ratio of PMMA increased as the weight ratio between MMA and nano-CaCO3 increased, while the grafting efficiency of PMMA decreased. Transmission electron micrograph showed that nano-CaCO3 covered with PMMA was formed by in-situ emulsion polymerization.

  3. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  4. Synthesis of polymer latex particles decorated with organically-modified laponite clay platelets via emulsion polymerization.

    Science.gov (United States)

    Herrera, Norma Negrete; Persoz, Stéphanie; Putaux, Jean-Luc; David, Laurent; Bourgeat-Lami, Elodie

    2006-02-01

    We report a new route to colloidal nanocomposites consisting of polymer latex particles covered with Laponite clay nanoplatelets. These composite particles are prepared by seeded emulsion (co)polymerization of styrene and butyl acrylate from Laponite clay suspensions previously functionalized by ion exchange using either a free radical initiator: 2,2-azobis (2-methylpropionamidine) hydrochloride (AIBA) or a cationic vinyl monomer: 2-(methacryloyloxy) ethyl trimethyl ammonium chloride (MADQUAT). The successful intercalation of the cationic reactive molecules was confirmed by elemental analysis, FTIR, 13C solid-state NMR and WAXD. The organically-modified clays were dispersed into water with the help of tetrasodium pyrophosphate and an anionic surfactant. stable latexes, produced under different experimental conditions, were successfully obtained from the clay suspensions. Cryo-TEM images of the resulting latexes showed spherical composite particles with diameters in the 50-250 nm range with clay sheets located on their surface. This paper reports on the effect of the processing conditions on the particle morphology and latex stability, and describes the mechanism of formation of the nanocomposite particles.

  5. Ionic liquid – Assisted emulsion polymerization of aniline in organic medium

    Energy Technology Data Exchange (ETDEWEB)

    Calheiros, Loan F. [Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas, 21941-598, Rio de Janeiro (Brazil); Soares, Bluma G., E-mail: bluma@metalmat.ufrj.br [Universidade Federal do Rio de Janeiro, PEMM-COPPE, Centro de Tecnologia, 21941-972, Rio de Janeiro (Brazil); Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas, 21941-598, Rio de Janeiro (Brazil); Barra, Guilherme M.O. [Universidade Federal de Santa Catarina, Mechanical Engineering Department, Florianópolis, SC (Brazil); Livi, Sébastien [Université de Lyon, F-69003, Lyon (France); INSA Lyon, F-69621, Villeurbanne (France); CNRS, UMR 5223, Ingénierie des Matériaux Polymères (France)

    2016-08-15

    Polyaniline doped with dodecylbenzene sulfonic acid (PAni.DBSA) with different conductivities and morphologies was prepared by inverted emulsion polymerization, in toluene using ammonium peroxydisulfate as the oxidizing agent, in the presence of two different imidazolium – based ionic liquids, such as, 1-methyl-3-butyl imidazolium tetrafluorate (bmim.BF{sub 4}) and 1-(11-carboxyundecyl)-3-methylimidazolium bromide (mimC{sub 10}COOH.Br). The influence of ionic liquid on the morphology and particle size of formed PAni.DBSA samples was investigated by field emission - scanning electron microscopy (FEG-SEM) and dynamic light scattering (DLS) measurements. Ultraviolet–visible measurements were also employed to confirm the structure of the conducting polymer. PAni.DBSA samples were also characterized by thermogravimetric analysis, cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). PAni.DBSA samples prepared in the presence of ionic liquids have shown improved dispersability in epoxy resin as indicated by optical micrograph. - Highlights: • Imidazolium-based ionic liquids as soft templates for polyaniline synthesis. • PAni with higher conductivity and different morphologies was achieved in the presence of IL. • Good IL/aniline salt interaction resulted in confinement inside PAni particles. • IL confinement confirmed by TGA and XPS analyses. • Excellent dispersability of PAni. DBSA prepared with ionic liquids, in epoxy matrix.

  6. Hg(II) adsorption using amidoximated porous acrylonitrile/itaconic copolymers prepared by suspended emulsion polymerization.

    Science.gov (United States)

    Ji, Chunnuan; Qu, Rongjun; Chen, Hou; Liu, Xiguang; Sun, Changmei; Ma, Caixia

    2016-01-01

    Initially, porous acrylonitrile/itaconic acid copolymers (AN/IA) were prepared by suspended emulsion polymerization. Successively, the cyano groups in AN/IA copolymers were converted to amidoxime (AO) groups by the reaction with hydroxylamine hydrochloride. The structures of the AN/IA and amidoximated AN/IA (AO AN/IA) were characterized by infrared spectroscopy, scanning electron microscopy, and porous structural analysis. The adsorption properties of AO AN/IA for Hg(II) were investigated. The results show that AO AN/IA has mesopores and macropores, and surface area of 11.71 m(2) g(-1). It was found that AO AN/IA has higher affinity for Hg(II), with the maximum adsorption capacity of 84.25 mg g(-1). The AO AN/IA also can effectively remove Hg(II) from different binary metal ion mixture systems. Furthermore, the adsorption kinetics and thermodynamics were studied in detail. The adsorption equilibrium can quickly be achieved in 4 h determined by an adsorption kinetics study. The adsorption process is found to belong to the second-order model, and can be described by the Freundlich model.

  7. Effect of carbon-black treatment by radiation emulsion polymerization on temperature dependence of resistivity of carbon-black-filled polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Jia Shaojin [Key Lab of Insulation and Thermal of Aging of Shanghai, Department of Polymer Engineering and Science, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240 (China) and Department of Chemical Engineering, Shanghai University, Chengzhong Road 20, Shanghai 201800 (China)]. E-mail: jiashaojin2@yahoo.com.cn; Jiang Pingkai [Key Lab of Insulation and Thermal of Aging of Shanghai, Department of Polymer Engineering and Science, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240 (China); Zhang Zhicheng [Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang Zhongguang [Key Lab of Insulation and Thermal of Aging of Shanghai, Department of Polymer Engineering and Science, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240 (China)

    2006-04-15

    High dispersibility and stability of carbon black particles in low-density-polyethylene (LDPE) matrix were obtained by radiation emulsion polymerization on carbon particles surface, and electrical resistivities of its simple were examined. First carbon particles treatment on radiation emulsion polymerization on surface were synthesized by the reaction with a polymer-emulsion systems containing reactive group in the molecular unit, carbon particles and emulsifier. Then, the carbon particles treatment on radiation emulsion polymerization on surface was dispersed into LDPE, and its composites were prepared for electrical measurements. The effect of radiation crosslinking of the composite on the Positive temperature coefficient (PTC) and negative temperature coefficient (NTC) phenomenon was investigated. The experimental results showed that PTC and NTC effects of the composites were obviously influenced by the irradiation dose. Various microstructure-exploring means were used to study the conductive composite, such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM)

  8. Effect of carbon-black treatment by radiation emulsion polymerization on temperature dependence of resistivity of carbon-black-filled polymer blends

    Science.gov (United States)

    Shaojin, Jia; Pingkai, Jiang; Zhicheng, Zhang; Zhongguang, Wang

    2006-04-01

    High dispersibility and stability of carbon black particles in low-density-polyethylene (LDPE) matrix were obtained by radiation emulsion polymerization on carbon particles surface, and electrical resistivities of its simple were examined. First carbon particles treatment on radiation emulsion polymerization on surface were synthesized by the reaction with a polymer-emulsion systems containing reactive group in the molecular unit, carbon particles and emulsifier. Then, the carbon particles treatment on radiation emulsion polymerization on surface was dispersed into LDPE, and its composites were prepared for electrical measurements. The effect of radiation crosslinking of the composite on the Positive temperature coefficient (PTC) and negative temperature coefficient (NTC) phenomenon was investigated. The experimental results showed that PTC and NTC effects of the composites were obviously influenced by the irradiation dose. Various microstructure-exploring means were used to study the conductive composite, such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM).

  9. PREPARATION OF MICRON-SIZED NONSPHERICAL POLYSTYRENE/POLY(STYRENE-co-ETHYLENEGLYCOL DIMETHACRYLATE)PARTICLES BY SEEDED SOAP-FREE EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Ze-feng Wang; Tao Wang; Li-na Bian; Li-min Zhou; Shah Shi; Shin-ichi Kuroda

    2011-01-01

    Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene (St) and ethyleneglycol dimethacrylate (EGDMA,used as a crosslinker) on spherical,linear polystyrene (PS) seed particles.The morphology of the resulting PS/poly(St-co-EGDMA) particles was dependent on the crosslinker concentration and polymerization temperature.

  10. Differences between the detonation behavior of emulsion explosives sensitized with glass or with polymeric micro-balloons

    Science.gov (United States)

    Mendes, R.; Ribeiro, J.; Plaksin, I.; Campos, J.; Tavares, B.

    2014-05-01

    The differences between the detonation behaviour of ammonium nitrate based emulsion explosives sensitized with polymeric and those sensitized with glass micro-balloons is presented and discussed. Expancel® are hollow polymeric micro-balloons that contain a hydrocarbon gas. The mean particle size of these particles is 30 μm with a wall thickness of about 0.1 μm. The detonation velocity and the failure diameter of the emulsion explosive sensitized with different amounts of these particles have been measured in cylindrical charges by optical fibers. The detonation velocity demonstrates non-linear behaviour in relation to density and reaches the maximum value for a density lower than that of the matrix. The detonation fails when the density approaches that of the matrix. The detonation in the emulsion explosives extinguishes itself at a porosity value that seems to be independent from the nature of the sensitizing agent. For low densities, the detonation velocity is almost independent of the charge diameter, and is close to the values predicted by BKW equation of state.

  11. Polystyrene/nano-SiO2 composite microspheres fabricated by Pickering emulsion polymerization: Preparation, mechanisms and thermal properties

    Directory of Open Access Journals (Sweden)

    W. H. Zhang

    2012-07-01

    Full Text Available We report the preparation, mechanisms and thermal properties of core-shell structured polymer/inorganic nanoparticle composite microspheres prepared by Pickering emulsion polymerization. Stable Pickering emulsion was firstly fabricated by using surface-modified nano-SiO2 particles as stabilizer. And then, two kinds of polystyrene/nano-SiO2 (PS/SiO2 composite microspheres with different sizes and morphologies were synthesized using hydrophobic azobisisobutyronitrile (AIBN and hydrophilic ammonium persulfate (APS as initiator, respectively. The possible mechanisms of Pickering emulsion polymerization initiated by different initiators were proposed according to the results of transmission electron microscope (TEM and scanning electron microscope (SEM. The chemical structure and molecular weight of the composite microspheres were characterized by Fourier transform infrared spectroscopy (FTIR, X-ray diffractometer (XRD and gel permeation chromatography coupled with a multi-angle laser light scattering photometer (GPC-MALLS. Thermogravimetric analysis (TGA and differential scanning calorimeter (DSC were used to comparatively analyze the thermal properties of nanocomposites and corresponding pure polymer. The results indicated that the decomposition temperature and glass transition temperature (Tg of nanocomposites were elevated to a certain degree due to the existence of nano-SiO2.

  12. Preparation of Inert Polystyrene Latex Particles as MicroRNA Delivery Vectors by Surfactant-Free RAFT Emulsion Polymerization.

    Science.gov (United States)

    Poon, Cheuk Ka; Tang, Owen; Chen, Xin-Ming; Pham, Binh T T; Gody, Guillaume; Pollock, Carol A; Hawkett, Brian S; Perrier, Sébastien

    2016-03-14

    We present the preparation of 11 nm polyacrylamide-stabilized polystyrene latex particles for conjugation to a microRNA model by surfactant-free RAFT emulsion polymerization. Our synthetic strategy involved the preparation of amphiphilic polyacrylamide-block-polystyrene copolymers, which were able to self-assemble into polymeric micelles and "grow" into polystyrene latex particles. The surface of these sterically stabilized particles was postmodified with a disulfide-bearing linker for the attachment of the microRNA model, which can be released from the latex particles under reducing conditions. These nanoparticles offer the advantage of ease of preparation via a scaleable process, and the versatility of their synthesis makes them adaptable to a range of applications.

  13. Radiation induced emulsion graft polymerization of 4-vinylpyridine onto PE/PP nonwoven fabric for As(V) adsorption

    Science.gov (United States)

    Akkaş Kavaklı, Pınar; Kavaklı, Cengiz; Seko, Noriaki; Tamada, Masao; Güven, Olgun

    2016-10-01

    A novel nonwoven fabric adsorbent having 4-vinylpyridine functional groups was prepared by using radiation-induced emulsion graft polymerization method and grafting 4-vinylpyridine monomer onto a polyethylene-coated polypropylene nonwoven fabric (NWF) in aqueous emulsion solution. The grafting conditions of the 4-vinylpyridine monomer onto the NWF were optimised and 150% Dg VP-g-NWF was prepared using 30 kGy pre-irradiation dose, 5% VP monomer concentration and 0.5% (w/w) Tween 20 in aqueous emulsion. Grafted 4-vinylpyridine chains on the NWF were then quaternized for the preparation of QVP-g-NWF adsorbent. All fabric structures were characterized by using Fourier-transform infrared spectrometer, x-ray photoelectron spectrometer and scanning electron microscope. QVP-g-NWF adsorbent was used in batch adsorption experiments for As(V) ions by studying the pH, contact time, and initial As(V) ion concentration parameters. Results showed that QVP-g-NWF adsorbent has significant As(V) adsorption and experimental As(V) adsorption capacity was 98.04 mg As(V)/g polymer from 500 mg/L initial As(V) concentration at pH 7.00.

  14. High-internal-phase-emulsion polymeric monolith coupled with liquid chromatography-electrospray tandem mass spectrometry for enrichment and sensitive detection of trace cytokinins in plant samples.

    Science.gov (United States)

    Du, Fuyou; Sun, Lin; Zhen, Xian; Nie, Honggang; Zheng, Yanjie; Ruan, Guihua; Li, Jianping

    2015-08-01

    High-internal-phase-emulsion polymers (polyHIPEs) show great promise as solid-phase-extraction (SPE) materials because of the tremendous porosity and highly interconnected framework afforded by the high-internal-phase-emulsion (HIPE) technique. In this work, polyHIPE monolithic columns as novel SPE materials were prepared and applied to trace enrichment of cytokinins (CKs) from complex plant samples. The polyHIPE monoliths were synthesized via the in-situ polymerization of the continuous phase of a HIPE containing styrene (STY) and divinylbenzene (DVB) in a stainless column, and revealed highly efficient and selective enrichment ability for aromatic compounds. Under the optimized experimental conditions, a method using a monolithic polyHIPE column combined with liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) was developed for the simultaneous extraction and sensitive determination of trans-zeatin (tZ), meta-topolin (mT), kinetin (K), and kinetin riboside (KR). The proposed method had good linearity, with correlation coefficients (R (2)) from 0.9957 to 0.9984, and low detection limits (LODs, S/N = 3) in the range 2.4-47 pg mL(-1) for the four CKs. The method was successfully applied to the determination of CKs in real plant samples, and obtained good recoveries ranging from 68.8 % to 103.0 % and relative standard deviations (RSDs) lower than 16 %.

  15. Synthesis of submicron-sized peanut-shaped poly(methyl methacrylate)/polystyrene particles by seeded soap-free emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    Shan Shi; Tao Wang; Yan Tao Tang; Li Min Zhou; Shin Ichi Kuroda

    2011-01-01

    Submicron-sized peanut-shaped poly(methyl methacrylate)/polystyrene (PMMA/PS) particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut-shaped particles showed a novel internal morphology: PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.

  16. Preparation of cross-linked microcapsules with spherical pores by in-situ polymerization in (W/O/W) emulsion system; (W/O/W) fukugo emulsion no in situ jugo wo riyoshita kakyo chuku microcapsule no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Ijichi, K.; Hatate, Y. [Kagoshima University, Kagoshima (Japan). Faculty of Engineering; Kiyoyama, S.; Shiomori, K.; Baba, Y.; Kawano, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

    1997-03-10

    The preparation of a microcapsule with submicron order spherical pores in particles was investigated by an in-situ polymerization method in the oil phase of a (W/O/W) emulsion system. Micro-encapsulation is useful as an immobilization method that can maintain or protect functional components in solid and control the emission of them to the air. However, it is hard to fine-control the spherical pores in particles. The toluene solution to which styrene monomer, divinyl-benzene, polymerization initiator, and surface active agent were added was used for oil phase. A sodium chloride or potassium nitrate solution was used for water phase. These solutions were emulsified to obtain W/O emulsion. The W/O emulsion was dispersed and emulsified into the outer water phase (surface active agent and polyvinyl alcohol) to obtain (W/O/W) emulsion. Styrene and divinyl-benzene were polymerized at a temperature of 333 K, then reduced in pressure and dried as a microcapsule. As a result, a microcapsule (of 10 to 20 {mu}m in diameter) with unevenness and spherical pores on the particle surface and in its inside was obtained. 6 refs., 6 figs., 1 tab.

  17. Annatto Polymeric Microparticles: Natural Product Encapsulation by the Emulsion-Solvent Evaporation Method

    Science.gov (United States)

    Teixeira, Zaine; Duran, Nelson; Guterres, Silvia S.

    2008-01-01

    In this experiment, the extract from annatto seeds was encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) particles by the emulsion-solvent evaporation method. The particles were washed and centrifuged to remove excess stabilizer and then freeze-dried. The main compound of annatto seeds, bixin, has antioxidant properties as well…

  18. Annatto Polymeric Microparticles: Natural Product Encapsulation by the Emulsion-Solvent Evaporation Method

    Science.gov (United States)

    Teixeira, Zaine; Duran, Nelson; Guterres, Silvia S.

    2008-01-01

    In this experiment, the extract from annatto seeds was encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) particles by the emulsion-solvent evaporation method. The particles were washed and centrifuged to remove excess stabilizer and then freeze-dried. The main compound of annatto seeds, bixin, has antioxidant properties as well…

  19. Porous and Magnetic Molecularly Imprinted Polymers via Pickering High Internal Phase Emulsions Polymerization for Selective Adsorption of λ-Cyhalothrin

    Science.gov (United States)

    Wu, Yunlong; Ma, Yue; Pan, Jianming; Gu, Runxing; Luo, Jialu

    2017-01-01

    A novel macroporous magnetic molecularly imprinted polymer (MMIPs) of was prepared by W/O Pickering (high internal phase emulsions) HIPEs polymerization, and then it was adopted as adsorbent for selective adsorption of λ-cyhalothrin (LC). In static conditions, adsorption capacity of LC increased rapidly in the first 60 min and reached to equilibrium in ~2.0 h. Excellent conformity of the second-order model confirmed the chemical nature of the interaction between the LC and imprinted sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption capacity at 298 K was 404.4 μmol g−1. Thermodynamic parameters suggested the specific adsorption at 298 K was an exothermic, spontaneous, and entropy decreased process. Competitive recognition studies of the MMIPs were performed with diethyl phthalate (DEP) and the structurally similar compound fenvalerate (FL), and the MMIPs, which displayed high selectivity for LC.

  20. Hollow microsphere with mesoporous shell by Pickering emulsion polymerization as a potential colloidal collector for organic contaminants in water.

    Science.gov (United States)

    Guan, Yinyan; Meng, Xiaohui; Qiu, Dong

    2014-04-08

    Submicrometer hollow microspheres with mesoporous shells were prepared by a simple one-pot strategy. Colloidal silica particles were used as a particle stabilizer to emulsify the oil phase, which was composed of a polymerizable silicon monomer (TPM) and an inert organic solvent (PEA). The low interfacial tension between colloidal silica particles and TPM helped to form a Pickering emulsion with small droplet sizes. After the polymerization of TPM, the more hydrophobic PEA formed a liquid core, leading to a hollow structure after its removal by evaporation. BET results indicated that the shell of a hollow particle was mesoporous with a specific surface area over 400 m(2)·g(-1). With PEA as the core and silica as the shell, each resultant hollow particle had a hydrophobic cavity and an amphiphilic surface, thus serving as a good colloidal collector for hydrophobic contaminants in water.

  1. Surface properties of latex film and solvent-borne film resulted from fluorinated acrylate copolymers prepared by emulsion polymerization

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The fluorinated acrylate copolymer, poly (BMA-co-DFHMA, was prepared by emulsion polymerization using a preemulsified monomer addition process. The FTIR and 1H –NMR were used to characterize the copolymer structure. The contact angle of water on the solvent-borne film increased dramatically and reached an equilibrium value (103° when the PDFHMA content in the copolymer was only 0.97 mol%. However, the contact of water on the latex film increased slowly, and reached the equilibrium value of 99° until the fluorinated component content was as highly as 9 mol%. A similar result was observed for the oil contact angle on the two types of films. XPS results showed that when the F/C ratio on film surfaces reached equilibrium, the required content of fluorinated component in the copolymer for the solvent-borne film was much lower than that for the latex film.

  2. Synthesis of composite particles through emulsion polymerization based on silica/fluoroacrylate-siloxane using anionic reactive and nonionic surfactants.

    Science.gov (United States)

    Qu, Ailan; Wen, Xiufang; Pi, Pihui; Cheng, Jiang; Yang, Zhuoru

    2008-01-01

    The composite particles with core/shell structure resulting from the combination of silica seed and hydrophobic copolymer (dodecafluoroheptyl methacrylate (DFMA), gamma-methacryloxypropyltriisopropoxidesilane (MAPTIPS), methyl methacrylate, butyl acrylate) were synthesized by emulsion polymerization. The amount of the silica seeds, concentration of reactive surfactant, as well as the addition of DFMA and MAPTIPS, have strong influences on the morphology of composite particles. It has been shown that it would be possible to produce stable organic/inorganic composite particles with inhomogeneous core/shell structure encapsulated by hydrophobic fluorinated acrylate even though using unmodified silica particles and admixture of anionic and nonionic surfactants. However, there was an obvious difference on the morphologies of core-shell structure whether the DFMA and MAPTIPS were added or not. It was concluded that two kinds of polymerization approaches might coexist in the presence of DFMA and MAPTIPS for raw silica. One clear advantage of this process is that there is only one silica bead for each composite particle. This kind of stable core-shell structural hybrid latex is useful for preparing high performance hydrophobic coating.

  3. Nonionic Polymerizable Emulsifier in High-Solids-Content Acrylate Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    LU Deping; HUANG Hongzhi; SHEN Ling; XIE Jin; GUAN Rong

    2012-01-01

    Stable high-solids-content acrylate emulsion were obtained with a nonionic polymerizable emulsifier allyloxy nonylphenoxy poly (ethyleneoxy) (10) ether (ANPEO10),and a conventional emulsifier OP-10 as a reference sample.1H NMR proves that the polymerizable emulsifier ANPEO10 has been incorporated into the resulted acrylate polymers.TEM demonstrates that there are some differences in the particle morphologies.AFM proves that the polymerizable emulsifier ANPEO10 migrating to the surface of the emulsion film was much less than the conventional emulsifier OP-10.The polymerizable emulsifier ANPEO10 can enhance the adhesion with glass plate compared to the conventional emulsifier.Furthermore,with increasing amount of emulsifier,the surface free energy of the films first decreased and then increased,and the adhesion with glass plate is initially enhanced and then attenuated.The water-resistance and solvent-resistance of the films prepared by the polymerizable emulsifier ANPEO10 are superior to those prepared by the conventional emulsifier OP-10.

  4. Preparation of polystyrene/SiO2 microsphere via Pickering emulsion polymerization: Synergistic effect of SiO2 concentrations and initiator sorts

    Science.gov (United States)

    Zhou, Haiou; Shi, Tiejun; Zhou, Xun

    2013-02-01

    In this paper, polystyrene (PS)/SiO2 microspheres were successfully prepared via Pickering emulsion polymerization stabilized solely by ethacryloxypropyltrimethoxysilane (MPTMS) modified SiO2 nanoparticles. The formation mechanisms of PS/SiO2 microspheres with different morphology were investigated under various Pickering emulsion polymerization conditions. The results showed that SiO2 concentrations and initiator sorts would synergistically impact on the morphology of products corresponding to distinct formation mechanisms. When SiO2 concentrations was low and water-solute initiator potassium persulfate (KPS) was used, aqueous nucleation was dominant, which was deduced to the formation of dispersive microspheres sparsely anchored by SiO2 particles. When SiO2 concentrations was increased and oil-solute initiator azobisisobutyronitrile (AIBN) was applied, nucleation in oil phase prevailed which lead to the formation of microspheres densely packed by SiO2 particles.

  5. In situ emulsion cationic polymerization of isoprene onto the surface of graphite oxide sheets

    Science.gov (United States)

    Pazat, Alice; Beyou, Emmanuel; Barrès, Claire; Bruno, Florence; Janin, Claude

    2017-02-01

    Grafting of polymers onto graphite oxide sheets (GO) has been widely studied in recent years due to the numerous applications of GO-based composites. Herein, polyisoprene (PI) chains were anchored on the surface of GO by in situ cationic polymerization using a "grafting through" approach with allyltrimethoxysilane-modified GO (GO-ATMS). First, the functionalization of GO sheets through the hydrolysis-condensation of allyltrimethoxysilane (ATMS) molecules was qualitatively evidenced by infra-red spectroscopy and X-ray photoelectron spectrometry and a weight content of 4% grafted ATMS was calculated from thermogravimetric analysis. Then, isoprene was in situ polymerized through a one-pot cationic mechanism by using a highly water-dispersible Lewis acid surfactant combined catalyst. For comparison, it was shown that the cationic polymerization of isoprene in presence of un-functionalized GO sheets led to a polyisoprene weight content on the solid filler divided by 3 compared to GO-ATMS. Finally, the compounding of the modified GO/PI composites was performed at a processing temperature of 80 °C with 2 phr and 15 phr loadings and it was shown a decrease of the air permeability coefficient of 27% for the vulcanizates with 15 phr loading.

  6. Application of mercapto-silica polymerized high internal phase emulsions for the solid-phase extraction and preconcentration of trace lead(II).

    Science.gov (United States)

    Su, Rihui; Ruan, Guihua; Chen, Zhengyi; Du, Fuyou; Li, Jianping

    2015-12-01

    A new class of solid-phase extraction column prepared with grafted mercapto-silica polymerized high internal phase emulsion particles was used for the preconcentration of trace lead. First, mercapto-silica polymerized high internal phase emulsion particles were synthesized by using high internal phase emulsion polymerization and carefully assembled in a polyethylene syringe column. The influences of various parameters including adsorption pH value, adsorption and desorption solvents, flow rate of the adsorption and desorption procedure were optimized, respectively, and the suitable uploading sample volumes, adsorption capacity, and reusability of solid phase extraction column were also investigated. Under the optimum conditions, Pb(2+) could be preconcentrated quantitatively over a wide pH range (2.0-5.0). In the presence of foreign ions, such as Na(+) , K(+) , Ca(2+) , Zn(2+) , Mg(2+) , Cu(2+) , Fe(2+) , Cd(2+) , Cl(-) and NO3 (-) , Pb(2+) could be recovered successfully. The prepared solid-phase extraction column performed with high stability and desirable durability, which allowed more than 100 replicate extractions without measurable changes of performance. The feasibility of the developed method was further validated by the extraction of Pb(2+) in rice samples. At three spiked levels of 40.0, 200 and 800 μg/kg, the average recoveries for Pb(2+) in rice samples ranged from 87.3 to 105.2%.

  7. EMULSION POLYMERIZATION OF THIOPHENE – THE NEW WAY OF CONDUCTING POLYMERS SYNTHESIS

    Directory of Open Access Journals (Sweden)

    Jacek Nowaczyk

    2015-08-01

    Full Text Available The aim of this study was to investigate the new method of polythiophene polymerization. It was made an attempt of the chemical oxidation of thiophene in aqueous medium without the addition of any surfactant. The oxidative compound applied in the synthesis was gaseous ozone. Resulting polymer was obtained in the form of nano-spheres dispersed in water. The method developed in this study allow to obtain the polythiophene nanoparticles. Further study is required to fully identify the resulting product properties in comparison with polymer obtained in other methods.

  8. Fire retardancy of emulsion polymerized poly (methyl methacrylate)/cerium(IV) dioxide and polystyrene/cerium(IV) dioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Guipeng [Department of Chemistry and Fire Retardant Research Facility, Marquette University, PO Box 1881, Milwaukee, WI 53201 (United States); Lu, Hongdian [Department of Chemical and Materials Engineering, Hefei University, Hefei, Anhui 230022 (China); Zhou, You; Hao, Jianwei [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Wilkie, Charles A., E-mail: charles.wilkie@marquette.edu [Department of Chemistry and Fire Retardant Research Facility, Marquette University, PO Box 1881, Milwaukee, WI 53201 (United States)

    2012-12-10

    Highlights: Black-Right-Pointing-Pointer We prepare PMMA and PS containing ceria. Black-Right-Pointing-Pointer Characterization by XRD and TEM shows that some of the ceria is well-dispersed in the polymers. Black-Right-Pointing-Pointer The addition of ceria to both polymers leads to reduced thermal stability. Black-Right-Pointing-Pointer In PMMA, the fire retardancy is enhanced but there is little effect in PS. - Abstract: In situ emulsion polymerization was employed to obtain poly (methyl methacrylate) (PMMA)/cerium(IV) dioxide and polystyrene (PS)/cerium(IV) dioxide nanocomposites at two different cerium(IV) dioxide loadings (2.3 wt% and 4.6 wt%). Transmission electron microscope results indicated uniform dispersion of cerium (IV) dioxide in the polymer matrix. Both PMMA and PS nanocomposites exhibit lower thermal stability than the pristine polymers. Microscale combustion calorimeter (MCC) and cone calorimetry are used to evaluate the fire retardancy of the polymer nanocomposites. PMMA/cerium(IV) dioxide showed significant heat release rate (HRR) reduction at low loadings (<5 wt%), while PS/cerium(IV) dioxide exhibits less HRR reduction at the same loadings. An explanation of the role of cerium (IV) dioxide in fire retardancy of polymer/ceria nanocomposites based on XPS results is suggested.

  9. Synthesis and Characterization of Encapsulated Nanosilica Particles with an Acrylic Copolymer by in Situ Emulsion Polymerization Using Thermoresponsive Nonionic Surfactant

    Directory of Open Access Journals (Sweden)

    Daryoosh Vashaee

    2013-08-01

    Full Text Available Nanocomposites of encapsulated silica nanoparticles were prepared by in situ emulsion polymerization of acrylate monomers. The synthesized material showed good uniformity and dispersion of the inorganic components in the base polymer, which enhances the properties of the nanocomposite material. A nonionic surfactant with lower critical solution temperature (LCST was used to encapsulate the silica nanoparticles in the acrylic copolymer matrix. This in situ method combined the surface modification and the encapsulation in a single pot, which greatly simplified the process compared with other conventional methods requiring separate processing steps. The morphology of the encapsulated nanosilica particles was investigated by dynamic light scattering (DLS and transmission electron microscopy (TEM, which confirmed the uniform distribution of the nanoparticles without any agglomerations. A neat copolymer was also prepared as a control sample. Both the neat copolymer and the prepared nanocomposite were characterized by Fourier transform infrared spectroscopy (FTIR, thermal gravimetric analyses (TGA, dynamic mechanical thermal analysis (DMTA and the flame resistance test. Due to the uniform dispersion of the non-agglomerated nanoparticles in the matrix of the polymer, TGA and flame resistance test results showed remarkably improved thermal stability. Furthermore, DMTA results demonstrated an enhanced storage modulus of the nanocomposite samples compared with that of the neat copolymer, indicating its superior mechanical properties.

  10. High Molecular Weight Thermally Stable Poly (Sodium Methacrylate / Magnetites Nanocomposites Via Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Rasha A. El-Ghazawya,

    2014-04-01

    Full Text Available Core/shell type magnetite nanocomposites (MN were synthesized using sodium methacrylate (NMA monomer. Functionalized and bare magnetite nanoparticles were prepared by conventional co-precipitation method giving particles with 3-10 nm in diameter. Microemulsion polymerization was used for constructing core/shell structure with magnetite nanoparticles as core and poly (sodium methacrylate as shell. Chemical structure and morphology of the synthesized PNMA/magnetite nanocomposites were investigated using FTIR and TEM, respectively. The synthesized nanocomposites show effective encapsulation of different treated magnetite nanoparticles in the polymer matrix and exhibited good thermal stability. Such magnetite nanocomposites with high molecular weight and thermal stability have potential application in enhanced oil recovery application.

  11. Influence of diblock copolymer PCL-mPEG and of various iodinated oils on the formulation by the emulsion-solvent diffusion process of radiopaque polymeric nanoparticles.

    Science.gov (United States)

    Hallouard, François; Briançon, Stéphanie; Anton, Nicolas; Li, Xiang; Vandamme, Thierry; Fessi, Hatem

    2013-11-01

    This pioneer study in the domain of blood pool contrast media formulation presents the influence of poly-ɛ-caprolactone-monomethoxy poly(ethylene glycol) (PCL-mPEG) and oils on the formulation of polymeric nanoparticles by emulsion-solvent diffusion. The nature of the oil used had no influence on the encapsulation rate, even if particles were formulated with a mix of PCL/PCL-mPEG. It did, however, influence the particle size and polydispersity, with macroglycerides appearing to be the lipid structure best suited to obtain the smallest monodisperse particles. When we used PCL-mPEG to form a PEG-hydrated layer to surround the nanoparticles, its tension active property had a favorable effect on particle size and polydispersity. We also showed the strong deleterious effect on particle size and polydispersity when the polymer proportion was increased to over 1% (w/v) in the pre-emulsion organic phase. Conversely, increasing the oil proportion in this organic phase simply resulted in a slight to insignificant deleterious effect on size and polydispersity, enabling the oil proportion to be enhanced up to 3% (w/v). Finally, we showed the favorable combined effect of oil iodination and the presence of PCL-mPEG on particles formulated by emulsion-solvent diffusion leading to the preparation of smaller polymeric iodine-containing particles.

  12. 反应型乳化剂在丙烯酸酯无皂乳液聚合中的应用%Application of reactive emulsifier in soap-free emulsion polymerization of acrylates

    Institute of Scientific and Technical Information of China (English)

    徐维环; 李少香

    2015-01-01

    A soap-free acrylate emulsion was prepared by semi-continuous seeded emulsion polymerization using butyl acrylate (BA), styrene (St), and methyl methacrylate (MMA) as monomers and sodium allyloxy hydroxy propanesulfonate (HAPS), ammonium allyloxy nonylphenol polyoxyethylene(10) ether sulfate (DNS-86), allyloxy nonylphenoxy poly(ethyleneoxy) (10) ether (ANPEO10), or allyloxy nonylphenoxy poly(ethyleneoxy) (10) ether monophosphoric acid (ANPEO10-P1) or the mixture of them as reactive emulsifier. The effects of type and amount of reactive emulsifier on properties of emulsion were analyzed. The chemical structure of the emulsion was characterized by Fourier-transform infrared spectroscopy (FT-IR). The water resistance and flame retardance of the inflating water-based fire-retardant coatings prepared by presented acrylate soap-free emulsion and commercial acrylic emulsion were compared through water resistance test and cone calorimetry. The results showed that the emulsion has the best chemical, thermal, and storage stabilities when only DNS-86 is used. The comprehensive performance of the emulsion obtained with 2.5%-3.0%DNS-86 is optimal:the largest solid content and monomer conversion, while the smallest average particle size, polydispersity index, and water contact angle of the film obtained therefrom. The performances of inflating water-based fire-retardant coating prepared by the home-made soap-free acrylate emulsion are apparently superior to that obtained by the commercial acrylic emulsion.%采用半连续种子乳液聚合法,反应型乳化剂烯丙氧基羟丙磺酸钠(HAPS)、烯丙氧基壬基酚聚氧乙烯醚硫酸铵(DNS-86)、烯丙氧基壬基酚聚氧乙烯醚(ANPEO10)、烯丙氧基壬基酚聚氧乙烯醚单磷酸(ANPEO10-P1)单独及复配使用,以丙烯酸丁酯(BA)、苯乙烯(St)、甲基丙烯酸甲酯(MMA)为单体合成了丙烯酸酯无皂乳液。研究了反应型乳化剂种类和用量对乳液性能的影响,用傅里叶

  13. Xyloglucan-Functional Latex Particles via RAFT-Mediated Emulsion Polymerization for the Biomimetic Modification of Cellulose.

    Science.gov (United States)

    Hatton, Fiona L; Ruda, Marcus; Lansalot, Muriel; D'Agosto, Franck; Malmström, Eva; Carlmark, Anna

    2016-04-11

    Herein, we report a novel class of latex particles composed of a hemicellulose, xyloglucan (XG), and poly(methyl methacrylate) (PMMA), specially designed to enable a biomimetic modification of cellulose. The formation of the latex particles was achieved utilizing reversible addition-fragmentation chain transfer (RAFT) mediated surfactant-free emulsion polymerization employing XG as a hydrophilic macromolecular RAFT agent (macroRAFT). In an initial step, XG was functionalized at the reducing chain end to bear a dithioester. This XG macroRAFT was subsequently utilized in water and chain extended with methyl methacrylate (MMA) as hydrophobic monomer, inspired by a polymerization-induced self-assembly (PISA) process. This yielded latex nanoparticles with a hydrophobic PMMA core stabilized by the hydrophilic XG chains at the corona. The molar mass of PMMA targeted was varied, resulting in a series of stable latex particles with hydrophobic PMMA content between 22 and 68 wt % of the total solids content (5-10%). The XG-PMMA nanoparticles were subsequently adsorbed to a neutral cellulose substrate (filter paper), and the modified surfaces were analyzed by FT-IR and SEM analyses. The adsorption of the latex particles was also investigated by quartz crystal microbalance with dissipation monitoring (QCM-D), where the nanoparticles were adsorbed to negatively charged model cellulose surfaces. The surfaces were analyzed by atomic force microscopy (AFM) and contact angle (CA) measurements. QCM-D experiments showed that more mass was adsorbed to the surfaces with increasing molar mass of the PMMA present. AFM of the surfaces after adsorption showed discrete particles, which were no longer present after annealing (160 °C, 1 h) and the roughness (Rq) of the surfaces had also decreased by at least half. Interestingly, after annealing, the surfaces did not all become more hydrophobic, as monitored by CA measurements, indicating that the surface roughness was an important factor to

  14. Influence of pumpkin seed oil in continuous phase on droplet size and stability of water-in-oil emulsions

    Directory of Open Access Journals (Sweden)

    Nikolovski Branislava G.

    2011-01-01

    Full Text Available The aim of this work was to contribute to the optimized production of water-in-oil emulsions with pumpkin seed oil in the oil phase using a high-speed homogenizer. Pumpkin seed oil is a valuable natural source of essential fatty acids and biologically active micronutrients that contribute to its nutritive value and medical uses, and reduce interfacial tension between water and the oil phases. Therefore, pumpkin seed oil can be considered as a prosperous oil phase whose use can possibly decrease the amount of some emulsifier that is normally involved in every emulsification process. A central composite rotatable experimental design was implemented to analyze the impact of the contents of polyglycerol polyricinoleate and pumpkin seed oil in the continuous phase, as well as water phase content in the emulsion on droplet size distribution and the response surface methodology was used to obtain optimal conditions for water-in-oil emulsion preparation. Mean size diameter of water droplets was in a range from 400 to 850 nm, with mean peak width of 100 to 220 nm, respectively. The influence of all three investigated factors on the emulsification was determined. Additionally, the emulsions prepared with pumpkin seed oil showed a higher stability during the storage time compared to the emulsions with sunflower oil.

  15. Bio-Functional, Lanthanide-Labeled Polymer Particles by Seeded Emulsion Polymerization and their Characterization by Novel ICP-MS Detection.

    Science.gov (United States)

    Thickett, Stuart C; Abdelrahman, Ahmed I; Ornatsky, Olga; Bandura, Dmitry; Baranov, Vladimir; Winnik, Mitchell A

    2010-01-01

    We present the synthesis and characterization of monodisperse, sub-micron poly(styrene) (PS) particles loaded with up to and including 10(7) lanthanide (Ln) ions per particle. These particles have been synthesized by seeded emulsion polymerization with a mixture of monomer and a pre-formed Ln complex, and analyzed on a particle-by-particle basis by a unique inductively coupled plasma mass cytometer. Seed particles were prepared by surfactant-free emulsion polymerization (SFEP) to obtain large particle sizes in aqueous media. Extensive surface acid functionality was introduced using the acid-functional initiator ACVA, either during seed latex synthesis or in the second stage of polymerization. The loading of particles with three different Ln ions (Eu, Tb, and Ho) has proven to be close to 100 % efficient on an individual and combined basis. Covalent attachment of metal-tagged peptides and proteins such as Neutravidin to the particle surface was shown to be successful and the number of bound species can be readily determined. We believe these particles can serve as precursors for multiplexed, bead-based bio-assays utilizing mass cytometric detection.

  16. 反相乳液聚合法合成聚丙烯酸纳米及微米颗粒%Synthesis of poly( acrylic acid) nano- and microparticles using an inverse emulsion polymerization method

    Institute of Scientific and Technical Information of China (English)

    葛建芳; 丁文; 卢凤纪

    2001-01-01

    Latices of water-swollen poly(acrylic acid) nano- and microparticles were synthesized using an inverse(w/o) emulsion polymerization method. They are stabilized by a co- emulsifier system consisting of Span80 and Tween80 dispersed in aliphatic hydrocarbons. The initial polymerization medium contains emulsion droplets and inverse micelles which solubilize a part of the monomer solution. The polymerization is initiated by free radicals, and particle dispersions with a narrow size distribution are obtained. The particle size is dependent on the type of radical initiator used. With water- soluble initiators, for example ammonium persulfate, microparticles were obtained in the size range of micro - size. When lipophilic radical initiators, such as azo - bis - isobutyronitrile, are used, almost exclusively nanoparticles are generated , due to the limited solubility of oligomeric poly(acrylic acid) chains in the lipophilic continuous phase.%采用反相乳液聚合方法,合成纳米及微米级尺寸的聚丙烯酸吸水性颗粒.将Span-80和Twoon-80组成的协同乳化体系分散于烷烃介质,使聚合体系稳定化.聚合初期,单体存在于乳化液滴和胶束中.在自由基引发下,聚合得到的聚丙烯酸颗粒大小均一,且其尺寸取决于引发剂的类型.若使用水溶性引发剂,如过硫酸铵,得到微米级的颗粒;若使用油溶性的偶氮二异丁腈作引发剂,由于丙烯酸的齐聚物分子链在油性连续相中溶解受限,则得到纳米级颗粒.

  17. Polymeric emulsion and crosslink-mediated synthesis of super-stable nanoparticles as sustained-release anti-tuberculosis drug carriers.

    Science.gov (United States)

    Choonara, Yahya E; Pillay, Viness; Ndesendo, Valence M K; du Toit, Lisa C; Kumar, Pradeep; Khan, Riaz A; Murphy, Caragh S; Jarvis, Debbie-Leigh

    2011-10-15

    This study focused on evaluating four emulsion-based processing strategies for polymeric nanoparticle synthesis to explicate the mechanisms of nanoparticle formation and the influence on achieving sustained-release of two anti-tuberculosis drugs, isoniazid and rifampicin. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were formulated with and without sorbitan mono-oleate as a stabilizer using emulsion-solvent-surfactant-evaporation (ESSE) and emulsion-solvent-evaporation (ESE) approaches. An alginate solution gelled by ionic crosslinking with calcium chloride was employed to prepare alginate hydrogel nanoparticles via reverse-emulsion-cationic-gelification (RECG) and reverse-emulsion-surfactant-cationic-gelification (RESCG) approaches. In vitro drug release analysis was performed. The size, zeta potential and morphology of the nanoparticles were analyzed. Molecular mechanics energy relationships (MMER) were employed to explore the spatial disposition of alginate and PLGA with respect to the emulsifying profile of sorbitan monooleate and to corroborate the experimental findings. Results revealed that particle size of the PLGA nanoparticles was influenced by the stabilizer concentration. Nanoparticles synthesized by the ESSE approach had smaller sizes of 240±8.7 nm and 195.5±5.4 nm for rifampicin- and isoniazid-loaded nanoparticles, respectively. This was a substantial size reduction from nanoparticles generated by the ESE approach (>1000 nm). The RESCG approach produced stable and higher nanoparticle yields with desirable size (277±1.0 nm; 289±1.2 nm), a low polydispersity index (27.1±0.3 mV; 28.5±0.5 mV) and drug entrapment efficiency of 73% and 75% for isoniazid and rifampicin, respectively. Drug release from the ESSE and RESCG synthesized nanoparticles displayed desirable release of the two anti-TB drugs with sustained zero-order kinetics over a period of 8h. MMER supported the mechanisms of nanoparticle formation with a sphericalized interlaced network

  18. Synthesis of crosslinked poly(styrene--divinylbenzene--sulfopropyl methacrylate) nanoparticles by emulsion polymerization: Tuning the particle size and surface charge density

    Indian Academy of Sciences (India)

    Dhamodaran Arunbabu; Mousumi Hazarika; Somsankar Naik; Tushar Jana

    2009-12-01

    We have synthesized highly charged, crosslinked poly (styrene--divinylbenzene--sulfopropyl methacrylate) copolymer colloidal particles using emulsion polymerization. The effects of concentration of the emulsifier and the initiator on the particle size and the charge density of the colloidal particles are studied. Colloidal particle size is highly dependent upon the concentration of the emulsifier and the initiator. The colloidal particle diameter decreases with increasing concentration of the emulsifier and increases with increasing concentration of the initiator in the polymerization mixture. Number of particles, surface charge density and charges per particle are also functions of both the emulsifier and the initiator concentration. The surface charge density and the number of charges per sphere increase with increasing particle diameter. These copolymer colloid particles self assemble readily and diffract visible light. Polymer hydrogel imbibed with these colloids shows the light diffraction.

  19. The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

    Directory of Open Access Journals (Sweden)

    K. A. Shaffei

    2009-01-01

    Full Text Available Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of polybutyl acrylate were achieved by using bis (2-ethylhexyl maleate (BEHM. The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

  20. Studies on the formation of polymeric nano-emulsions obtained via low-energy emulsification and their use as templates for drug delivery nanoparticle dispersions.

    Science.gov (United States)

    Calderó, G; Montes, R; Llinàs, M; García-Celma, M J; Porras, M; Solans, C

    2016-09-01

    Ethylcellulose nanoparticles have been obtained from O/W nano-emulsions of the water/polyoxyethylene 10 oleyl ether/[ethyl acetate+4wt% ethylcellulose] system by low energy-energy emulsification at 25°C. Nano-emulsions with droplet sizes below 200nm and high kinetic stability were chosen for solubilising dexamethasone (DXM). Phase behaviour, conductivity and optical analysis studies of the system have evidenced for the first time that both, the polymer and the drug play a role on the structure of the aggregates formed along the emulsification path. Nano-emulsion formation may take place by both, phase inversion and self-emulsification. Spherical polymeric nanoparticles containing surfactant, showing sizes below 160nm have been obtained from the nano-emulsions by organic solvent evaporation. DXM loading in the nanoparticles was high (>90%). The release kinetics of nanoparticle dispersions with similar particle size and encapsulated DXM but different polymer to surfactant ratio were studied and compared to an aqueous DXM solution. Drug release from the nanoparticle dispersions was slower than from the aqueous solution. While the DXM solution showed a Fickian release pattern, the release behaviour from the nanoparticle dispersions was faster than that expected from a pure Fickian release. A coupled diffusion/relaxation model fitted the results very well, suggesting that polymer chains undergo conformational changes enhancing drug release. The contribution of diffusion and relaxation to drug transport in the nanoparticle dispersions depended on their composition and release time. Surfactant micelles present in the nanoparticle dispersion may exert a mild reservoir effect. The small particle size and the prolonged DXM release provided by the ethylcellulose nanoparticle dispersions make them suitable vehicles for controlled drug delivery applications.

  1. Sulfonate-containing Copolymers Prepared by Semi-Continuous Emulsion Copolymerizaiton of Styrene and Sodium Styrene Sulfonate

    Institute of Scientific and Technical Information of China (English)

    Shiming HUANG; Wei XIE; Chengyou KAN; Yajie LI; Deshan LIU

    2005-01-01

    @@ 1Introduction Soap-free emulsion copolymerization of styrene (St) and sodium sulfonate styrene (NaSS) could yield homodisperse sulfonate-containing particles with clean surface. But the incorporation of NaSS could never be increased beyond 2.6 % by weight in the conventional batch and seeded emulsion copolymerization in the absence of emulsifier because large amounts of soluble polyelectrolyte would unstablize the reaction system if excessive amount of NaSS was used[1]. In our work, semi-continuous copolymerizations were carried out in the presence of mixed emulsifiers, and a new method to purify the latex polymer was developed. The influences of the NaSS mole ratio in the total monomers and the monomer addition time on the S content in the purified copolymer were investigated by elemental analysis.

  2. Use of alginate, chitosan and cellulose nanocrystals as emulsion stabilizers in the synthesis of biodegradable polymeric nanoparticles.

    Science.gov (United States)

    Rescignano, Nicoletta; Fortunati, Elena; Armentano, Ilaria; Hernandez, Rebeca; Mijangos, Carmen; Pasquino, Rossana; Kenny, José Maria

    2015-05-01

    Biopolymeric nanoparticles (NPs) based on a biodegradable poly(DL-Lactide-co-Glycolide) PLGA copolymer matrix combined with alginate, chitosan and nanostructured cellulose crystals as three different natural emulsion stabilizers, were synthesized by a double emulsion (water/oil/water) method with subsequent solvent evaporation. The morphological, thermal, chemical and rheological properties of the novel designed NPs and the effect of the different emulsion stabilizers used during the synthesis were deeply investigated in order to optimize the synthesis procedure and the development of biodegradable nanoparticles coated with natural polymers. The morphological analysis of the produced nanoparticles showed that all the different formulations presented a spherical shape with smooth surface. Infrared spectroscopy investigations showed that the PLGA copolymer maintained its backbone structure and confirmed the presence of chitosan, alginate and cellulose nanocrystals (CNC) on the nanoparticle surface. The obtained results suggest that PLGA nanoparticles with CNC as emulsion stabilizer might represent promising formulations opening new perspective in the field of self-assembly of biodegradable nanomaterials for medical and pharmaceutical applications.

  3. Emulsion polymerization of methylmethacrylate initiated by ultraviolet irradiation%紫外光引发甲基丙烯酸甲酯乳液聚合

    Institute of Scientific and Technical Information of China (English)

    张敏娟; 张爱珍; 张力

    2013-01-01

    A 60 W high pressure mercury lamp was used as the light source to initiate the emulsion polymerization of methylmethacrylate (MMA) monomer in the presence of azodiisobuty-ronitrile as the major photoinitiator. The effects of irradiation time, concentration of monomer, and concentration of photointiator on the conversion rate of MMA monomer were investigated. A transmission electron microscope was performed to observe the morphology of as-obtained emulsion and determine the size of the emulsion particles as well. Results show that the conversion rate rises with the increase of irradiation time and monomer concentration as well. The highest conversion rate is obtained at a photoinitiator concentration of 3% (mass fraction) , and the conversion rates tends to decline with further increase of the photoinitiator concentration above 3%.%以60 W高压汞灯为光源,以偶氮二异丁氰(AIBN)为主要光引发剂,以甲基丙烯酸甲酯(MMA)为单体进行乳液聚合,考察了光照时间、单体浓度、光引发剂浓度等因素对单体转化率的影响;采用透射电镜观察了乳胶粒的形态,并测定了其尺寸.结果表明,转化率随光照时间和单体浓度的增加而上升;当光引发剂质量分数为3%时单体转化率最高.

  4. Preparation of multihollow P(St-MAA) particles by sequence soap-free/soap emulsion polymerization and followed by stepwise alkali/acid posttreatment

    Institute of Scientific and Technical Information of China (English)

    Rong Long Li; Cheng You Kan; Ze Ping Li; Yi Du; Yan Nan Cui

    2007-01-01

    The effects of ionic emulsifier, sodium dodecylbenzene sulfate (SDBS), on the formation of the multihollow structures in sub-micron sized polymer particles produced by alkali/acid posttreatment were investigated.The original latex particles with narrow size distribution were synthesized by a new sequence emulsifier-free/emulsifier emulsion copolymerization of styrene (St) and methacrylic acid (MAA).Results indicated that the pore size decreased and the pore number increased with the increase of SDBS amount, and the morphology of the posttreated latex particles was also significantly influenced by the introducing time of SDBS in the preparation of the original latex particles, and a suitable introducing time was 3 h of polymerization.

  5. INFLUENCES OF ACID POST-TREATMENT ON THE MORPHOLOGY OF SOAP-FREE P(MMA-EA-MAA) PARTICLES PREPARED BY SEEDED EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Kai Kang; Cheng-you Kan; Yi Du; De-shan Liu

    2005-01-01

    Soap-free poly(methyl methacrylate-ethyl acrylate-methacrylic acid) latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

  6. Molecularly imprinted polymer microspheres prepared by Pickering emulsion polymerization for selective solid-phase extraction of eight bisphenols from human urine samples.

    Science.gov (United States)

    Yang, Jiajia; Li, Yun; Wang, Jincheng; Sun, Xiaoli; Cao, Rong; Sun, Hao; Huang, Chaonan; Chen, Jiping

    2015-05-01

    The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30-60 μm), a specific surface area (S(BET)) of 281.26 m(2) g(-1) and a total pore volume (V(t)) of 0.459 cm(3) g(-1). Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2-2.2 ng mL(-1). The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL(-1) for each BP) were in the range of 81.3-106.7% with RSD values below 8.3%.

  7. STUDY ON THE FORMATION MECHANISM OF MONODISPERSE PARTICLES IN THE EMULSIFIER-FREE EMULSION POLYMERIZATION OF METHYL METHACRYLATE AND BUTYL ACRYLATE

    Institute of Scientific and Technical Information of China (English)

    Hong-quan Xie; Gui-ying Liao; Yu Gao

    2003-01-01

    The formation mechanism of monodisperse polymer latex particles in the emulsifier-free emulsion polymerization of methyl methacrylate and butyl acrylate with potassium persulfate as initiator was investigated. A multi-step formation mechanism for the monodisperse polymer particles was proposed. The nucleation mechanism is considered to be the coagulation of the precursor particles by homogeneous nucleation when the primary particles reach a critical size with high surface charge density and sufficient stability. It had been proved by a special experiment that the early latex particles formed by the coagulation were stable. The primary particles grow by absorbing monomers and radicals in the polymerization system and then become colloidally unstable again due to the understandable decrease of particle surface charge density, which leads to the aggregation of the growing particles and the formation of larger latex particles therefrom. After the nucleation period,the preferential aggregation of the smaller particles in the propagation process leads to the change of the particles towards a uniform size and narrower particle size distribution. The coexistence and competition of homogeneous nucleation,coagulation, propagation and aggregation result in the increase of the polydispersity index (U = D43/D10) in the first stage,then its decrease in the later stage because of the competition of propagation and aggregation, and the gradual formation of the monodisperse particles.

  8. Synthesis of poly (methyl methacrylate)-b-polystyrene with high molecular weight by DPE seeded emulsion polymerization and its application in proton exchange membrane.

    Science.gov (United States)

    Wang, Wenwen; Zhang, Hepeng; Geng, Wangchang; Gu, Junwei; Zhou, Yanyang; Zhang, Junping; Zhang, Qiuyu

    2013-09-15

    In this article, we present poly (methyl methacrylate)-b-polystyrene (PMMA-b-PS) with different block ratios and high molecular weight, which was synthesized by environmentally friendly seeded emulsion polymerization with 1,1-diphenylethylene (DPE) as a chain transfer agent. Polymerization kinetics in the first and second stage was investigated. Stable latex and homogeneous latex particles were obtained with the characterization of laser light scattering (LLS) and transmission electron microscopy (TEM). SEC and (1)H NMR revealed the successful preparation of block copolymers with high molecular weight and two different block ratios. The morphology of microphase separation of block copolymer thin films was investigated by AFM, and long-range order lamellar morphology was observed after vapor-annealing. The block copolymer with block ratio of almost 1:1 and higher molecular weight than that of previous PMMA-b-PS was sulfonated with acetyl sulfate, and the sulfonation was confirmed by FTIR, (1)H NMR, and TGA. Then, the sulfonated PMMA-b-PS was casted as membranes. The electrochemical impedance spectroscopy displayed that membranes possessed favorable proton conductivity and fine dimensional stability, and they could be candidates as proton exchange membranes.

  9. Molecularly imprinted polymer microspheres prepared by Pickering emulsion polymerization for selective solid-phase extraction of eight bisphenols from human urine samples

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jiajia [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yun; Wang, Jincheng [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Sun, Xiaoli; Cao, Rong [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Sun, Hao [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Department of Chemistry, Liaoning University, Shenyang 110000 (China); Huang, Chaonan [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jiping, E-mail: chenjp@dicp.ac.cn [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China)

    2015-05-04

    Highlights: • BPA imprinted polymer microspheres were prepared by Pickering emulsion polymerization. • Regular spherical shape and narrow diameter distribution. • Good specific adsorption capacity for BPA. • Good class-selectivity and clean-up efficiency for bisphenols in human urine under SPE mode. • Good recoveries and sensitivity for bisphenols using the MIPMS-SPE coupled with HPLC-DAD method. - Abstract: The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption–desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30–60 μm), a specific surface area (S{sub BET}) of 281.26 m{sup 2} g{sup −1} and a total pore volume (V{sub t}) of 0.459 cm{sup 3} g{sup −1}. Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2–2.2 ng mL{sup −1}. The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL{sup −1} for each BP) were in the range of 81.3–106.7% with RSD values below 8.3%.

  10. Synthesis of palladium nanoparticles using a continuous flow polymeric micro reactor.

    Science.gov (United States)

    Song, Yujun; Kumar, Challa S S R; Hormes, Josef

    2004-09-01

    A continuous flow polymeric micro reactor, fabricated using a negative photo resist SU-8 on a 10 x 10 cm PEEK (polyetheretherketone) substrate by standard UV lithography, was utilized to synthesize palladium nanoparticles. The nanoparticles were characterized by Transmission Electron Microscopy, Selected Area Electron Diffraction and X-ray Diffraction. The Pd nanoparticles synthesized in the micro reactor were found to have a narrower size distribution when compared with those obtained by the conventional batch process.

  11. AQUEOUS STABLE FREE RADICAL POLYMERIZATION PROCESSES

    Institute of Scientific and Technical Information of China (English)

    Andrea R. Szkurhan; Michael K. Georges

    2004-01-01

    An overview of aqueous polymerizations, which include emulsion, miniemulsion and suspension polymerizations,under stable free radical polymerization (SFRP) conditions is presented. The success of miniemulsion and suspension SFRP polymerizations is contrasted with the difficulties associated with obtaining a stable emulsion polymerization. A recently developed unique microprecipitation technique is referenced as a means of making submicron sized particles that can be used to achieve a stable emulsion SFRP process.

  12. 悬浮态乳液聚合条件对聚氯乙烯树脂颗粒特性的影响%Influence of Suspended Emulsion Polymerization Conditions on Particle Characteristics of Polyvinyl Chloride Resin

    Institute of Scientific and Technical Information of China (English)

    包永忠; 魏真理; 翁志学; 黄志明

    2003-01-01

    Suspended emulsion polymerization of vinyl chloride was carried out in a 5 L autoclave. The influenceof agitation, polymerization conversion, dispersant and surfactant on the average particle size (PS) and particle sizedistribution (PSD), particle morphology and porosity of polyvinyl chloride (PVC) resin was investigated. It showedthat the agitator had great influence on the smooth operation of polymerization, PS and PSD. The PS increasedand PSD became narrow as polymerization conversion became high. The porosity decreased with the increase ofconversion. A convenient choice of additives, both dispersants and non-ionic surfactants, allows one to adjust PSand PSD. The PS decreased with the addition of polyvinyl alcohol or hydroxypropyl methylcellulose dispersants,and increased with the addition of Span surfactants. The addition of dispersants or surfactants also affected themorphology and porosity of resin, and PVC resin with looser agglomeration and homogeneous distribution of primaryparticles was prepared.

  13. Research progress review of solid particles stabilized Pickering emulsion and polymerization%固体颗粒稳定的 Pickering 乳液及其聚合研究述评

    Institute of Scientific and Technical Information of China (English)

    刘瑞雪; 段瑞卿; 岳英英; 张晓静; 方少明

    2014-01-01

    Recent advances in Pickering emulsion stabilized by solid particles and Pickering emulsion poly-merization were reviewed.It pointed out that the main stability theories of Pickering emulsion were the in-terface theory and the contact angle theory.The influence factors of Pickering emulsion included solid par-ticle concentration,pH value and the type of electrolyte,etc.SiO2 ,Laponite and magnetite had been commonly used as solid stabilizers in Pickering emulsion polymerization.The shortages on Pickering emul-sion research were also pointed out,such as neglecting the influence of electrical properties of solid parti-cles and deficient research on lamellar colloidal particles as Pickering emulsion stabilizer.Preparing the new Pickering emulsion less affected by monomer with stable properties,so as to enrich Pickering emulsion and its joint technology will be the research focus in the future.%综观国内外学者近年对固体颗粒稳定的 Pickering 乳液及其聚合的研究,相关理论有界面理论和接触角理论,对其影响因素的分析主要有固体颗粒浓度、水相 pH 值和水相电解质。研究者已经将SiO2,Laponite 粘土,磁铁矿等一系列无机固体颗粒成功地应用于 Pickering 乳液中,并制备出一系列性能各异的材料,但研究工作仍存在一些不足,如忽略固体颗粒的电性质对 Pickering 乳液的影响,对 Pickering 乳液的片状胶体颗粒稳定剂的研究不系统等。制备受单体影响小、性能稳定的新型 Pick-ering 乳液聚合稳定剂,从而不断丰富 Pickering 乳液及其聚合技术将是未来研究的热点。

  14. 淀粉-丙烯酰胺反相乳液聚合%Starch-acrylamide polymer was prepared by inverse emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    武世新; 杨红丽

    2012-01-01

    采用反相乳液聚合,以淀粉、丙烯酰胺为原料,过硫酸铵为引发剂制备了淀粉丙烯酰胺聚合物.实验表明,最佳反应条件为:引发剂加量为单体总量的0.1%,油水体积比为1∶1,反应温度为60℃,反应时间为4h.淀粉丙烯酰胺聚合物的除浊率可达89%,吸水率达350%.%The polymer was prepared by inverse emulsion polymerization, starch and acrylamide as raw materials. Ammonium persulfate as the initiator prepared starch-acrylamide polymer. The experimental showed that the optimum reaction conditions were as follows:mass ratio of initiator to monomer is 0. 1% , oil to water volume ratio is 1:1, reaction temperature is 60 ℃ ,and reaction time is 4 h. The starch-acrylamide polymer turbidity removal rate up to 89% ,and water absorption up to 350%.

  15. Interfacial Polymerization of Dopamine in a Pickering Emulsion: Synthesis of Cross-Linkable Colloidosomes and Enzyme Immobilization at Oil/Water Interfaces.

    Science.gov (United States)

    Qu, Yanning; Huang, Renliang; Qi, Wei; Su, Rongxin; He, Zhimin

    2015-07-15

    Colloidosomes are promising carriers for immobilizing enzyme for catalytic purposes in aqueous/organic media. However, they often suffer from one or more problems regarding catalytic performance, stability, and recyclability. Here, we report a novel approach for the synthesis of cross-linkable colloidosomes by the selective polymerization of dopamine at oil/water interfaces in a Pickering emulsion. An efficient enzyme immobilization method was further developed by covalently bonding enzymes to the polydopamine (PDA) layer along with the formation of such colloidosomes with lipase as a model enzyme. In this enzyme system, the PDA layer served as a cross-linking layer and enzyme support for simultaneously enhancing the colloidosomes' stability and improving surface availability of the enzymes for catalytic reaction. It was found that the specific activity of lipases immobilized on the colloidosome shells was 8 and 1.4 times higher than that of free lipase and encapsulated lipase positioned in the aqueous cores of colloidosomes, respectively. Moreover, the immobilized lipases demonstrated excellent operational stability and recyclability, retaining 86.6% of enzyme activity after 15 cycles. It is therefore reasonable to expect that this novel approach for enzyme immobilization has great potential to serve as an important technique for the construction of biocatalytic systems.

  16. Continuous treatments of estrogens through polymerization and regeneration of electrolytic cells

    Energy Technology Data Exchange (ETDEWEB)

    Cong, Vo Huu, E-mail: cong@aoni.waseda.jp; Sakakibara, Yutaka, E-mail: sakaki@waseda.jp

    2015-03-21

    Highlights: • Trace natural and synthetic estrogens were removed effectively by electrochemical oxidation process. • Removal efficiency of 93–98% was achieved through electrochemical polymerization. • Passivated electrodes were completely recovered to their initial conditions in continuous operation. • Removal performance could be controlled and enhanced by a mathematical model. - Abstract: This study proposes a novel electrolytic method for simultaneous removal of trace estrogens and regeneration of electrolytic cells for long-term wastewater treatment. Continuous treatments of estrogens estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) were theoretically and experimentally studied using an electrolytic reactor equipped with a multi-packed granular glassy carbon electrode reactor. Experimental results demonstrated that E1, E2 and EE2 were effectively removed through electro-polymerization on the granular glassy carbon (and Pt/Ti) anode counter. Polymer formed during continuous treatment was quickly decomposed and electrodes were regenerated completely by ·OH radicals produced through the reduction of ozone. Calculated overall energy consumptions were less than 10 Wh/m{sup 3}, demonstrating extremely low energy consumptions. In addition, a mathematical model developed based on the limiting mass transfer rate and post-regeneration could represent general trends in time series data observed in experiments.

  17. Continuous treatments of estrogens through polymerization and regeneration of electrolytic cells.

    Science.gov (United States)

    Cong, Vo Huu; Sakakibara, Yutaka

    2015-03-21

    This study proposes a novel electrolytic method for simultaneous removal of trace estrogens and regeneration of electrolytic cells for long-term wastewater treatment. Continuous treatments of estrogens estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) were theoretically and experimentally studied using an electrolytic reactor equipped with a multi-packed granular glassy carbon electrode reactor. Experimental results demonstrated that E1, E2 and EE2 were effectively removed through electro-polymerization on the granular glassy carbon (and Pt/Ti) anode counter. Polymer formed during continuous treatment was quickly decomposed and electrodes were regenerated completely by ˙OH radicals produced through the reduction of ozone. Calculated overall energy consumptions were less than 10 Wh/m(3), demonstrating extremely low energy consumptions. In addition, a mathematical model developed based on the limiting mass transfer rate and post-regeneration could represent general trends in time series data observed in experiments.

  18. Modelagem da polimerização simultânea de estireno em suspensão e emulsão Modeling styrene simultaneous suspension and emulsion polymerization systems

    Directory of Open Access Journals (Sweden)

    Marcelo K. Lenzi

    2004-06-01

    Full Text Available Apesar dos processos de polimerização em suspensão e emulsão serem processos heterogêneos, cada um origina características peculiares para a distribuição de tamanho de partículas, distribuição de pesos moleculares, taxa de nucleação das partículas de polímero, taxa de polimerização, entre outras. Neste trabalho, são realizadas polimerizações de estireno simultaneamente em suspensão e emulsão. A carga inicial do reator equivale à receita de uma polimerização em suspensão tradicional, enquanto os constituintes da emulsão são adicionados ao longo da batelada. Analisa-se como as propriedades finais do polímero e o curso da polimerização dependem do momento em que a carga característica da emulsão é adicionada à polimerização em suspensão. Apresenta-se, também, um modelo matemático para a descrição do sistema, sendo que o modelo proposto possui boa concordância com dados experimentais de conversão, pesos moleculares médios e curva de distribuição de pesos moleculares. A morfologia da partícula de polímero e os pesos moleculares médios mudam significativamente, dependendo do momento da adição da emulsão, podendo até mesmo ser obtidas curvas de distribuição de pesos moleculares bimodais. Verificou-se que as partículas apresentam características do tipo núcleo/casca, sendo o núcleo formado pelas partículas obtidas pela polimerização em suspensão e a casca formada pelas partículas do processo em emulsão.Although both emulsion and suspension polymerization processes are performed in heterogeneous media, each process presents its own typical characteristics, such as the particle size distribution, molecular weight distribution, polymer particle nucleation rates, rates of polymerization, and so on. In this work styrene polymerizations are carried out in suspension and emulsion processes simultaneously. The initial reactor charge resembles the recipe of standard styrene suspension

  19. 浓乳液法聚苯乙烯/聚甲基丙烯酸丁酯自增容合金的制备%AUTO-COMPATILIZATION OF POLYSTYRENE/POLY (BUTYL METHACRYLATE) BLEND VIA CONCENTRATED EMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    黄皓浩; 杜中杰; 励杭泉

    2001-01-01

    将由水相引发部分预聚的苯乙烯(St)浓乳液与部分预聚的甲基丙烯酸丁酯(BMA)浓乳液混合,并使混合物继续聚合至完全,利用单体在不同乳胶粒间的扩散所生成的两种准嵌段共聚物来降低聚苯乙烯与聚甲基丙烯酸丁酯两相间的界面张力,使之起到增容作用,改善聚苯乙烯/聚甲基丙烯酸丁酯合金性能,获得自增容合金。%Two concentrated emulsions in water were prepared: one from butyl methacrylate(BMA) and other from styrene(St). After the concentrated emulsions were partially pre-polymerized, they were mixed and subjected to complete polymerization. Because monomers diffused across water into cells each other during the subsequent polymerization, two types of quasi-block copolymers were generated. Such quasi-block copolymer as compatibilizers existed at the interfaces and decreased the interfacial tension. The compatibilization made the domain of the dispersed phase finer and the interface between the matrix and the toughener smeared and thus improved the combination of the two components. As a result, auto-compatible blend, possessing excellent toughness, was obtained.

  20. Preparation of Fe{sub 3}O{sub 4}/poly(styrene-butyl acrylate-[2-(methacryloxy)ethyl]trimethylammonium chloride) by emulsifier-free emulsion polymerization and its interaction with DNA

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaolong; Liu Guoqiang; Yan Wei [Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Yeung, Kelvin W.K. [Division of Spine Surgery, Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam (Hong Kong); Wu Shuilin; Yi Changfeng [Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Division of Spine Surgery, Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam (Hong Kong); Xu Zushun, E-mail: zushun25@yahoo.com.cn [Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Division of Spine Surgery, Department of Orthopaedics and Traumatology, University of Hong Kong, Pokfulam (Hong Kong)

    2012-04-15

    Cationic magnetic polymer particles Fe{sub 3}O{sub 4}/poly(styrene-butyl acrylate-[2-(methacryloxy)ethyl]trimethylammonium chloride), a type of potential gene carrier, were prepared by emulsifier-free emulsion polymerization with oleic acid modified magnetite Fe{sub 3}O{sub 4}, styrene, butyl acrylate and [2-(methacryloxy)ethyl]trimethylammonium chloride) (METAC). The morphology of the particles was characterized by transmission electron microscopy and the composites of particles were characterized by FT-IR spectroscopy, X-ray diffraction. These results showed that magnetic particles were well dispersed in polymers with the content of about 15%(wt/wt). The composites exhibited superparamagnetism and possessed a certain level of magnetic response. The interactions between the particles with calf-thymus DNA (ct DNA) were confirmed by zeta potential measurement, UV-vis spectroscopy and fluorescence spectroscopy. The DNA-binding capacity determined by the agarose gel electrophoresis showed good binding capacity of the emulsion to DNA. These results suggested the potential of the cationic magnetic polymer emulsion as gene target delivery carrier. - Highlights: Black-Right-Pointing-Pointer A new type of cationic magnetic polymer particles was synthesized by emulsifier-free emulsion polymerization. Black-Right-Pointing-Pointer Structural, morphological, and magnetic properties of the composite were evaluated. Black-Right-Pointing-Pointer The interaction between cationic magnetic polymer particles with DNA was confirmed by zeta potential measurements. Black-Right-Pointing-Pointer UV-vis spectrophotometry, fluorescent spectroscopy and agarose gel electrophoresis. Black-Right-Pointing-Pointer This process may have potential applications to gene carrier and DNA separation.

  1. Effects of Hydrophilic Monomer Types and Level on Polystyrene-Acrylate/montmorillonite Nanocomposite Made by Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    F.A.Zhang; L.Chen; J.Q.Ma; X.Yang

    2007-01-01

    1 Results Nanocomposite has attracted more and more interest all over the world.Polystyrene (PS) is a commercialized and mass-productive polymer,continuous research efforts have been devoted to the development of polystyrene/montmorillonite (PS/MMT) nanocomposites[1-2].But the polarity of styrene (St) is too small to intercalate the space between the clay layers.The polarity of hydrophilic monomer is so strong that it can intercalate the MMT easily,the intercalated smectic clays maybe exfoliated by usin...

  2. Influences of redox initiator on properties and polymerization mechanism of acrylate emulsion%氧化还原引发剂对丙烯酸酯乳液性能及聚合机制的影响

    Institute of Scientific and Technical Information of China (English)

    崔金海; 范薇; 抚庆全; 姬学亮

    2011-01-01

    以过硫酸钾(KPS)和亚硫酸氢钠(NaHSO3)为自由基聚合体系的氧化-还原型引发剂,以十二烷基硫酸钠(SDS)和脂肪醇聚氧乙烯醚硫酸钠(AES)为阴/非离子型复合乳化剂,制备甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和甲基丙烯酸(MAA)共聚物乳液.研究了引发剂种类及用量对该乳液性能及聚合过程等影响,探讨并提出了酸性条件下丙烯酸酯乳液体系的新型引发机制.结果表明:在其他条件保持不变的前提下,当m(KPS)∶m(NaHSO3)=1.00∶0.45、w(KPS+NaHSO3)=0.6%时,乳液的单体转化率(98%)和黏度(5.900 Pa·s)相对最高,反应时间(2.0h)相对较短且初始聚合温度(60℃)相对最低,此时乳液质量最稳定.%With potassium persulfate(KPS) and sodium bisulfite (NaHSO3) as oxidant-reducer initiator of free radical polymerization system,sodium dodecyl sulfate(SDS) and sodium fatty alcohol ether sulfate(AES) as anionic-nonionic emulsifier, an acrylate copolymer emulsion based on methyl methacrylate (MMA), butyl acrylate (BA), methacrylic acid (M AA) was prepared. The influences of initiator types and contents on properties and polymerization process of the emulsion were investigated, and a new type polymerization initiating mechanism was discussed and presented for the acrylate emulsion system under acidic condition. The results showed that the emulsion had reversely maximal monomer conversion rate(98%) and viscosity(5.900 Pa·s),reversely shorter reaction time(2.0 h) .reversely lowest incipient polymerization temperature (60 ℃) and jarlessest quality when mass ratio of m(KPS):m(NaHSO3) was 1.00:0.45 and total mass fraction of KPS and NaHSO3 was 0.6%.

  3. A Novel Continuously Initiated Polymerization by One-Atmosphere Low Temperature Plasma Device

    Institute of Scientific and Technical Information of China (English)

    You qingliang; Meng yuedong; Wang jianhua; Ou qiongrong; Xu xu; Zhong shaofeng

    2005-01-01

    A novel atmospheric plasma device developed in this paper, which is more effective and convenient to study the plasma-initiated polymerization (PIP) than conventional setup. The structure and mechanism of the device is introduced. Some plasma-initiated polymerization experiments are carried out on the device, and the conversion of AA (Acrylic acid) and AM (Acryl amide) atmospheric (N2) plasma polymerization are respectively 89% and 94% after 120 h post polymerization, whereby IR spectra of the product (AA, AM). Our PIP result are confirmed.

  4. 紫外光引发Pickering乳液聚合制备中空复合微球的研究%Synthesis of Hollow Microspheres by Pickering Emulsion Polymerization Initiated by Ultraviolet Light

    Institute of Scientific and Technical Information of China (English)

    张卫红; 范晓东; 田威; 范伟伟; 程广文

    2011-01-01

    Hollow composite microspheres can be prepared rapidly by Pickering emulsion polymerization initiated by ultraviolet light.Firstly,nano-SiO2 were endowed with amphipathy and photosensitivity by grafting with 2-hydroxy-4'-(2-hydroxyethoxy)-2-methyl-propiophenone(IHT-PI 659).Secondly,stable Pickering emulsion was fabricated by using this functional nano-SiO2 particles as stabilizer.Finally,the SiO2/polymethylmethacrylate composite microspheres with hollow structure were successfully synthesized by Pickering emulsion polymerization initiated by ultraviolet light at room temperature.The products were characterized by Fourier transformation infrared spectrum(FTIR),thermogravimetric analysis(TGA),transmission electron microscopy(TEM) and scanning electron microscope(SEM).A possible mechanism for the formation of the hollow composites by photo-initiation Pickering emulsion polymerization was also proposed.%用光引发剂2-羟基-4'-(2-羟乙氧基)-2-甲基苯丙酮(IHT-PI 659)对纳米SiO2表面进行接枝使之兼具两亲性及光引发特性;以该功能性纳米SiO2为稳定剂构筑O/W(水包油)型Pickering乳液;用紫外光引发处于内油相的甲基丙烯酸甲酯单体聚合,制备出具有中空结构的SiO2/PMMA复合微球,采用傅里叶变换红外光谱(FTIR)、热失重分析仪(TGA)、透射电镜(TEM)及扫描电子显微镜(SEM)对复合微球进行了表征,并提出了紫外光引发Pickering乳液聚合制备中空复合微球的机理.

  5. ACUTE EFFECTS OF CONTINUOUS NASOGASTRIC TUBE-FEEDING ON GASTRIC FUNCTION - COMPARISON OF A POLYMERIC AND A NONPOLYMERIC FORMULA

    NARCIS (Netherlands)

    KLEIBEUKER, JH; BOERSMAVANEK, W

    1991-01-01

    The acute effects of continuous intragastric administration of 1500 ml (4200 kJ/liter) of a polymeric and of a nonpolymeric formula on gastric function were studied in 15 healthy subjects. During 450 min 1500 ml, containing 6300 kJ (1500 kcal), was given through a nasogastric tube. At regular interv

  6. Clickable Polylactic Acids by Fast Organocatalytic Ring-Opening Polymerization in Continuous Flow

    NARCIS (Netherlands)

    Berg, van den Sebastiaan A.; Zuilhof, Han; Wennekes, Tom

    2016-01-01

    The use of microreactor technology for the ring-opening polymerization of l-lactide catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene allows for rapid optimization of reaction parameters (reaction temperature and residence time). At moderate catalyst loading, good control over the polymerization i

  7. 辐射法制备水性聚氨酯-丙烯酸酯乳液及性能%Preparation of waterborne polyurethane-acrylate through radiation-induced emulsion polymerization and its related performance

    Institute of Scientific and Technical Information of China (English)

    孙学武; 葛沛; 汪太生; 王龙海; 吕建平

    2011-01-01

    ;辐射乳液聚合是一种在高能射线辐照下使介质分解成自由基而引发乳液聚合的方法。作者以二羟甲基丙酸(DMPA)、聚醚二元醇(N-220)、甲基丙烯酸-β-羟丙酯(HPMA)和异佛尔酮二异氰酸酯(IPDI)等为原料合成碳-碳双键封端的水性聚氨酯预聚物,用丙烯酸酯丁酯(BA)和甲基丙烯酸甲酯(MMA)混合单体降低体系黏度。经过机械乳化、中和、钴60γ-射线辐射聚合,制得了水性聚氨酯-丙烯酸酯(PUA)复合乳液。用红外光谱(FTIR)、粒径分析、热重分析(TGA)等对乳液粒子和膜性能进行了分析和表征。结果表明,与化%Radiation induced emulsion polymerization is one method that in high-energy rays the medium is decomposed into free radicals triggering emulsion polymerization.In this paper,a double bond terminated polyurethane prepolymer was synthesized with DMPA,N210,HPMA and IPDI,as raw materials.The obtained prepolymer was then mixed with MMA and BA to decrease its viscosity.Polyurethane-acrylate(PUA)could be obtained through mechanical emulsification,neutralization and copolymerization with MMA and BA by 60Co radiation(initiator).Casting film of PUA was characterized with FTIR,TGA,mechanical properties and water resistance tests.The results showed that the properties of PUA prepared through radiation induced emulsion polymerization were superior to that prepared with chemical initiator polymerization.Compared with the chemical method,the average particle size was decreased from 143.5 nm to 100 nm;solid content was increased from 37.5% to 38.6%;tensile strength was increased from 15.3 MPa to 18.3 MPa;water absorption rate of casting film was decreased from 7.4% to 5.6%;and initial thermal decomposition was increased from 320 ℃ to 380 ℃.The findings could provide guidance for the synthesis of PUA and related research.

  8. Preparation of nano composite latex of poly(butyl acrylate-co-methyl methacrylate) P (BA-co-MMA) and layered double hydroxide (LDH) by mini emulsion polymerization; Preparacao de latex nanocomposito de poli(acrilato de butila-co-metacrilato de metila) P (BA-co-MMA) e hidroxido duplo lamelar (HDL) por meio da tecnica de polimerizacao em miniemulsao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodrigo D.; Lona, Liliane M.F., E-mail: liliane@feq.unicamp.br [Universidade Estadual de Campinas - Unicamp, Faculdade de Engenharia Quimica, SP (Brazil); Dube, Marc A. [Universidade de Ottawa. Departamento de Engenharia Quimica e Biologica, Ottawa, ON (Canada)

    2011-07-01

    In the present work, the synthesis of polymeric nonconsumption (PNCs) of P(BA-coMMA) and layered LDH through mini emulsion polymerization (MEP) was studied. The commercial organically modified LDH Perkalite F100S was used as filler and octadecyl acrylate (ODA) as costabilizer of the mini emulsions. Two types of surfactant, a cationic and nonionic one, were investigated and the cationic one could not stabilize the system when the LDH was present. The polymerization kinetics was not significantly affected by the presence of LDH which kept the pH of the system constant during the reaction. The dispersion of the inorganic material in the polymeric matrix was evaluated by X-ray diffraction which suggested exfoliation of the LDH. (author)

  9. Scale-up of the Reversible Addition-Fragmentation Chain Transfer (RAFT Polymerization Using Continuous Flow Processing

    Directory of Open Access Journals (Sweden)

    Nenad Micic

    2014-01-01

    Full Text Available A controlled radical polymerization process using the Reversible Addition-Fragmentation Chain Transfer (RAFT approach was scaled up by a factor of 100 from a small laboratory scale of 5 mL to a preparative scale of 500 mL, using batch and continuous flow processing. The batch polymerizations were carried out in a series of different glass vessels, using either magnetic or overhead stirring, and different modes of heating: Microwave irradiation or conductive heating in an oil bath. The continuous process was conducted in a prototype tubular flow reactor, consisting of 6 mm ID stainless steel tubing, fitted with static mixers. Both reactor types were tested for polymerizations of the acid functional monomers acrylic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in water at 80 °C with reaction times of 30 to 40 min. By monitoring the temperature during the exothermic polymerization process, it was observed that the type and size of reactor had a significant influence on the temperature profile of the reaction.

  10. 无皂RAFT乳液聚合制备聚苯乙烯的阳离子型胶乳%Soap-Free Emulsion Polymerization of Styrene Using Macro-RAFT Agent to Make Cationic Latex

    Institute of Scientific and Technical Information of China (English)

    厉正赏; 罗英武

    2013-01-01

    A cationic amphiphilic macro-RAFT (reversible addition-fragmentation chain transfer) agent, P4VPm-b-PSn-CPDTTC (m=10, 15, 20, 30, n≈6), was synthesized as a surfactant in RAFT emulsion polymerization of styrene. The effects of neutralization degree and length of 4-vinylpyridine block of the agent on the soap-free emulsion polymerization were examined. The results show that a higher neutralization degree results in a longer inhibition period, and a longer 4-vinylpyridine block leads to a shorter inhibition period and a higher polymerization rate. The obtained latex particles have the average diameter of about 40 nm with a very wide range of particle size distribution. On the early stage of polymerization, the number-average molecular weight Mn of the obtained latex agreed well with what was predicted theoretically, but later on, it started to deviate; all of the polydispersity index (PDI) first rose, and then fell. At the end of polymerization, the PDIs were very high, and they increased with the increase of the neutralization degree.%设计合成了一系列可阳离子化两亲性大分子逆加成-断裂链转移(RAFT)试剂P4VPm-b-PSn-CPDTTC (m=10,15,20,30,n≈6),并考察了大分子RAFT试剂中和程度及4-乙烯基吡啶(4VP)段长度对苯乙烯的无皂RAFT乳液聚合的影响.结果发现,中和程度越高,阻聚期越长;4VP段越长,阻聚期越短,而聚合速率则越快;所得胶乳的粒径为40 nm左右,粒径分布很宽,反应前期数均分子量(Mn)的实验值与理论值吻合较好,中后期开始偏离;分子量分布指数(PDI)都是先升高后降低,反应结束后PDI很高,且随中和程度的增加而升高.

  11. 高转化率配方乳聚丁苯橡胶聚合过程中间产物性能考察%The intermediates properties of SBR in emulsion polymerization by a recipe with high monomer conversion

    Institute of Scientific and Technical Information of China (English)

    金彦江; 沈本贤; 隋军; 崔明海; 杨磊; 赵基钢

    2011-01-01

    The monomer conversion of styrene butadiene rubber(SBR) polymerization was studied by a lab scale autocalve with the large-scale production recipe of high conversion for SBR in Jilin Petrochemical Company. And then the intermediates properties such as the combining styrene content, organic acids and soap content, Mooney viscosity in emulsion polymerization were all determined. The results showed that the performances of synthesized product with the polymerization time of 10 hours and monomer conversion up to 70% can meet up with the superior grade requirements of GB/T 8655-2006,while the combining styrene content and Mooney viscosity of synthesized product with the polymerization time of 12 hours and monomer conversion of 75% can not meet up with the superior grade requirements of GB/T 8655-2006.%采用中国石油吉林石化公司乳聚丁苯橡胶高转化率大生产配方,考察了实验室聚合反应釜聚合反应单体转化率随反应时间的变化,测定了生胶的结合苯乙烯含量、有机酸和皂含量、门尼粘度等性质,结果表明:反应10h,转化率为70%左右时生胶的各项性质均达到标准GB/T 8655-2006中规定的优等品指标要求;当反应12h,转化率达到75%时,生胶的结合苯乙烯含量和门尼粘度不符合要求.

  12. Kinetics Model of Graft Co-Polymerization of Acrylamide onto Mechanically-Activated Starch in Inverse Emulsion%反相乳液法mSt-g-AM接枝共聚反应的动力学模型

    Institute of Scientific and Technical Information of China (English)

    谢新玲; 童张法; 黄祖强; 张友全

    2014-01-01

    The graft co-polymerization reaction mechanism of acrylamide and mechanically-activated starch in an inverse emulsion system was investigated. The effects of concentrations of initiator (with ammonium persulfate as the initiator), monomer, starch, and emulsifier on the reaction rate of graft co-polymerization (Rg) were determined. The kinetic model was studied and modified to fit the experimental results. The results show that the relationship between R g and the concentration of components in the polymerization system can be expressed for all of the four components by the following equation:Rg∞[mSt]1.24 [I]0.76 [M]1.54 [E]0.33 , which is consistent with the kinetic equation from theoretical studies:Rp∞[mSt]0.5~1 [I]0.5~1 [M]1~1.5 [E]0.6 . It can be concluded that the graft co-polymerization reaction of hydrophilic monomer onto starch in inverse emulsion follows the mechanism of free radical polymerization. Unimolecular and bimolecular termination of free radicals are both presented in the reaction process. The relation between the grafted monomer and the reacted monomer is:1/X=1+K1[M]0.5/[Mst]0.5+K2[Mst]0.5[I]0.5/[M]+K3[I]0.5/[Mst]0.5 .%采用反相乳液法进行淀粉与丙烯酰胺接枝共聚反应的机理研究,考察以过硫酸铵引发机械活化淀粉(mSt)与丙烯酰胺(AM)接枝共聚反应速率Rg与引发剂浓度[I]、乳化剂浓度[E]、单体浓度[M]和淀粉浓度[mSt]的关系,推导并验证该反应体系的动力学模型及反应机理。结果表明,本实验得出的动力学关系式为:Rg∞[mSt]1.24[I]0.76[M]1.54[E]0.33,与理论推导出的动力学关系式:Rp∞[mSt]0.5~1[I]0.5~1[M]1~1.5[E]0.6基本一致,机械活化淀粉与丙烯酰胺在反相乳液中进行接枝共聚反应符合自由基聚合机理;在聚合过程中,引发剂分解副反应、诱导分解及“笼壁效应”导致引发效率降低,单基终止和双基终止反应同时存在;推导出共聚物消耗单体量与参加反

  13. Determination of molecular weight and other characteristics of co- and terpolymers using automatic continuous online monitoring of polymerization reactions (ACOMP)

    Science.gov (United States)

    Enohnyaket, Pascal E. A.

    The Automatic Continuous Online Monitoring of Polymerization reactions (ACOMP), is a technique developed by the Reed Research Group at Tulane University. By simultaneously monitoring and combining signals from a continuously dilute reactor stream, detectors such as a multi-angle light scattering detector, near infra-red spectrometer, viscometer, differential refractive index, and a full wavelength UV/Visible detector were used in a model-independent fashion to follow the weight-average molecular weight, intrinsic viscosity, the concentrations of each comonomer, and hence the evolution of the average instantaneous and cumulative compositions along the chains as comonomers are consumed. The goal of this dissertation is to make the ACOMP system more useful in very complex polymerization situations by improving it with additional detectors and formalisms (such as a new expression for computing the molecular weight a copolymer of nth degree) and to exploit its robustness in situations where traditional routes fail or are of limited value. By providing a continuum of data, ACOMP allows polymer scientists to better understand and control new reaction schemes. At the pilot plant, it can be used to optimize reaction conditions. Because the ACOMP system is relatively cheap, user friendly, can be environmentally friendly, less bulky and very efficient, it is my desire to use ACOMP to solve some of the problems in the petroleum, plastic and drug manufacturing industries in Cameroon (and Africa).

  14. Preparation of self-crosslinked acrylate emulsion with high elasticity and its rheological properties

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-jun; WU Feng-qin; LI Dong-shuang; YANG Jian; LI Rong-xian

    2008-01-01

    Using butyl acrylate (BA), methyl methacrylate (MMA), methacrylic acid (MAA) and mixed emulsifier as raw materials, the self-crosslinked emulsion was prepared via pre-emulsified and semi-continuous seeded emulsion polymerization technology in the presence of N-hydroxymethyl acrylamide and poly solidum maleate. The influence of mass ratio of BA to MMA, amount of N-hydroxymethyl acrylamide and poly solidum maleate on the rheological properties of the self-crosslinked emulsion was studied. Possible cross-linked mechanism of self-crosslinked monomer was investigated. And the relationship between emulsion viscosity and shear rate was investigated. The results show that the self-crosslinked acrylate emulsion with high elasticity can be synthesized when the mass fractions of BA is 60%, MMA is 40%, and added amount of N-hydroxymethyl acrylamide is 2.5%-3.0% and added amount of poly solidum maleate is 0.3%-0.4%. The self-crosslinkage process of N-hydroxymethyl acrylamide involves two steps. One is copolymer zation of N-hydroxymethyl acrylamide and acrylate, the other is cross-linkage among polymer molecules via condensation reaction of methylol. The emulsion is of rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

  15. Preparation of PMMA/SBA-15 Composites Via In-Situ Emulsion Polymerization%原位乳液聚合法制备PMMA/SBA-15复合材料

    Institute of Scientific and Technical Information of China (English)

    宋程; 张发爱; 余彩莉

    2011-01-01

    Poly (methyl methacrylate) (PMMA)/SBA-15 (0,1% ,2. 5% ,5% ) composite materials are prepared with different loadings of mesoporous molecular sieve SBA-15 via in-situ emulsion polymerization, and the properties of as-prepared composite emulsions are investigated by infrared spectroscopy (IR) and X-ray diffraction (XRD).The results show that the PMMA/SBA-15 composites are prepared successfully. The composite emulsions demonstrate high monomer conversion and coagulum, low viscosity, relatively large particle size, and wide range of distribution. The PMMA/SBA-15 composite film exhibites greater storage modulus and higher Young's modulus when compared with pure PMMA (especially, the composite with 2. 5% SBA -15 displayed the greatest storage and Young's modulus). The glass transition temperature of the composites increases with the increase of mesoporous silica loading. TGA confirms that the thermal stabilities of PMMA/SBA-15 composites are not influenced apparently.%采用原位乳液聚合法制备了聚甲基丙烯酸甲酯(PMMA) /SBA-15介孔复合材料,研究了不同用量介孔硅SBA-15(0、1%、2.5%、5%)对PMMA/SBA-15介孔复合材料性能的影响.红外光谱(IR)和X射线衍射(XRD)分析表明成功制备了PMMA/SBA-15复合材料.以乳液聚合法制备的PMMA/SBA-15复合材料具有较高的单体转化率和固体含量,随着SBA-15用量的增加,聚合过程中凝聚率增大、粘度减小,复合乳液具有较大的粒径及更宽的粒径分布.动态力学分析(DMA)测试表明:PMMA/SBA-15复合材料储能模量和杨氏模量明显增大,且在SBA-15用量为2.5%时复合材料模量最高.差示扫描量热( DSC)测试表明:随着SBA-15用量增加,复合材料玻璃化温度提高.热重分析(TGA)结果证实复合材料热稳定性没有明显变化.

  16. 无皂乳液聚合法制备PS/TiO2核-壳复合微球%Preparation of PS/TiO2 core-shell composite microspheres by soap-free emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    李海东; 高文杰; 程凤梅; 白福臣

    2012-01-01

    A series of polystyrene microspheres was prepared via soap-free emulsion polymerization. Polystyrene microspheres was sulphonated, absorbed water and then the reaction was happened between sulfonated polysty- rene and TiO2 in ethanol with TBOT as a reaction precursor, the surface of sulphonated polystyrene micro- spheres was covered by TiO2 and organic-inorganic compound microspheres was acquired. Tangible functional group was grafted on compound microspheres surface, and core-shell -shell heterozygosity microspheres was ob- tained by grafting methyl methacrylate (MMA) on heterozygosity microspheres surface with soap-free emulsion polymerization. The organic-inorganic compound microspheres were characterized by means of Fourier trans- form infrared spectrometer, scanning electron microscope and thermal gravimetric analysis etc. The results show that PS,PS/TiO2 and PS/TiO2/PMMA microspheres surface smooth, spherical degree good and single good dispersancy;controllable shell thickness by change of the quantity of TBOT to PS/TiO2 composite micro- spheres.%采用无皂乳液聚合法制备聚苯乙烯(PS)微球,将所制备的PS微球经磺化吸水后,利用钛酸丁酯作前驱体在乙醇中反应,使TiO2包覆在磺化苯乙烯微球表面,得到有机-无机Ps/TiO2复合微球。在所得的杂化微球表面接枝上可聚官能团,利用无皂乳液聚合将聚甲基丙烯酸甲酯聚合到微球表面,得到核-壳-壳杂化微球。用FT—IR、SEM和TGA等方法对所制得的复合微球进行表征。结果表明PS、PS/TiO2及PS/TiO2/PMMA微球表面光滑,球形度好,单分散性良好;通过改变TBOT的加入量可以控制TiO。对PS微球的包覆厚度。

  17. Lipid emulsions

    Directory of Open Access Journals (Sweden)

    Robins, Margaret M.

    2000-04-01

    Full Text Available Emulsions are liquid-liquid mixtures with one liquid contained as droplets within the other. The droplets are typically 1mm in diameter, and the properties of the emulsions are very dependent on the droplet structure, which is stabilised by surface-active emulsifier molecules. Most food emulsions are made from the raw ingredients using an homogenisation process to form small droplets. The paper describes methods of measuring droplet size and emulsion stability, and discusses the physical origin of emulsion texture, flavour and appearance.Las emulsiones son mezclas líquido-líquido con un líquido contenido en forma de gotas dentro de otro líquido. Las gotas tienen normalmente 1 mm de diámetro y las propiedades de las emulsiones dependen en gran medida de la estructura de la gota, la cual está estabilizada por las moléculas emulsionantes. La mayoría de las emulsiones alimenticias están constituidas a partir de materias primas usando un proceso de homogeneización que permite formar gotas pequeñas. El artículo describe métodos de medida del tamaño de gota y estabilidad de las emulsiones, y discute el origen físico de la textura, flavor y apariencia de la emulsión.

  18. Fluid Dynamic Characterization of a Polymeric Heart Valve Prototype (Poli-Valve) tested under Continuous and Pulsatile Flow Conditions

    Science.gov (United States)

    De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D.; Costantino, Maria Laura

    2016-01-01

    Introduction Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy, the latter display better fluid dynamic behaviour but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the haemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of two groups of newly developed supra-annular tri-leaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. Methods Two types of Poli-Valves made of SBC differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. An ad - hoc designed pulse duplicator allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the valve’s behaviour. Results Both types Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by ISO 5840 Standard. Results were compared with five mechanical heart valves (MHVs) and five tissue heart valves (THVs), currently available on the market. Conclusion Based on these results, polymeric heart valves based on styrenic block copolymers, as Poli-Valves are, can be considered as promising alternative for heart valve replacement in near future. PMID:26689146

  19. Synthesis of reactive emulsifiers and their application in acrylate emulsion polymerization%反应性乳化剂的制备及其在纯丙乳液聚合中的应用

    Institute of Scientific and Technical Information of China (English)

    徐进进; 闵洁; 虞鑫海; 田太洲

    2014-01-01

    将马来酸酐分别与苯甲醇、正辛醇、十二醇、十四醇和脂肪醇聚氧乙烯醚AEO-7通过酯化、中和反应生成相应的产物,依次记为ME-B,ME-8,ME-12,ME-14和M-AEO-7,测试并对比了各产物乳化力和临界胶束浓度的大小。结果表明ME-12和M-AEO-7的综合性能较佳。采用红外光谱对2者的结构进行表征。分别将十二烷基硫酸钠SDS、ME-12和M-AEO-7用于纯丙乳液聚合中,发现采用自制的反应性乳化剂所得乳液的聚合稳定性和乳胶膜的耐水性比SDS有所提高。将ME-12分别和AEO-3(AEO-5或AEO-7)以1∶1或1∶1.5质量比复配使用,仅在mME-12∶mAEO-7=1∶1.5时乳液的耐电解质稳定性才较好,而单独采用M-AEO-7即能得到耐电解质性能极佳的聚合物乳液。%Maleic anhydride was esterified with benzyl alcohol,n-octanol, lauryl alcohol, tetradecyl alcohol and fatty alcohol ethoxylates AEO-7,respectively,and then neutralized.The corresponding products were marked as ME-B, ME-8, ME-12, ME-14 and M-AEO-7. The emulsifying power and critical micelle concentration were measured and compared, the results showed that comprehensive performance of ME-12 and M-AEO-7 were better, and their structures were confirmed by infrared spectroscopy. Sodium dodecyl sulfate SDS, ME-12 and M-AEO-7 were used for acrylate emulsion polymerization, it found that the polymerization stability of the resulting emulsions and water resistance of its latex films prepared with homemade reactive emulsifiers were better than that for SDS. The ME-12 was also used by combing with AEO-3(AEO-5 or AEO-7) in the ratio of 1 to 1 or 1 to 1.5(by weight) respectively, it turned out that only when the ratio of ME-12 to AEO-7 was 1 to 1.5, the stability against the electrolytes was better. However, using M-AEO-7 alone was able to get the polymer emulsion with excellent electrolyte resistance.

  20. Preparation of acrylonitrile butadiene rubber by soap-free emulsion polymerization%无皂乳液聚合制备丁二烯-丙烯腈橡胶

    Institute of Scientific and Technical Information of China (English)

    桂强; 梁琨; 钟启林; 马朋高; 张元寿; 王真琴

    2011-01-01

    In this paper,soap-free acrylonitrile butadiene rubber was prepared using sulfate polymerisable emulsifier KD SE-10 by emulsion copolymerization at low temperature. The article studied the influence of the amount of polymerisable emulsifier on mooney viscosity, bound acrylonitrile content, the gel ratio, tensile strength and molecular weight. And the amount of KD SE-10 was determined as 2. 7%~3.0wt%. Acrylonitrile butadiene rubber prepared has the remarkable characteristics of high-strength,excellent oil resistance and narrow molecular weight distribution.%采用硫酸盐类可聚合乳化剂烯丙氧基壬基苯氧基丙醇聚氧乙烯醚硫酸铵(KD SE-10)通过低温乳液聚合法制备无皂丁腈橡胶.详细考察了可聚合乳化剂用量对门尼粘度、结合丙烯腈含量、凝胶量、拉伸强度、相对分子质量的影响情况,并确定了KD SE-10用量为2.7%~3.0%(质量分数).制得的无皂丁腈橡胶相比普通丁腈橡胶具有显著的高强度、更优良的耐油性、相对分子质量分布窄的特点.

  1. Encapsulation of emulsion droplets by organo–silica shells

    NARCIS (Netherlands)

    Zoldesi, C.; Steegstra, Patrick; Imhof, Arnout

    2007-01-01

    Surfactant-stabilized emulsion droplets were used as templates for the synthesis of hollow colloidal particles. Monodisperse silicone oil droplets were prepared by hydrolysis and polymerization of dimethyldiethoxysiloxane monomer, in the presence of surfactant: sodium dodecyl sulphate (SDS, anionic)

  2. CORROSION RESISTANCE OF THE FLAKY ALUMINUM POWDER COATED BY EMULSION POLYMERIZATION%乳液聚合法包覆片状铝粉及其耐腐蚀性研究

    Institute of Scientific and Technical Information of China (English)

    梁伟; 叶红齐; 陈玉琼; 刘秀云

    2011-01-01

    以丙烯酸丁酯、苯乙烯为单体,十二烷基硫酸钠为乳化剂,过硫酸铵为引发剂,通过乳液共聚包覆在片状铝粉的表面,并探讨单体配比、反应温度、反应时间对包覆铝粉耐酸腐蚀性能的影响.结果表明,在单体丙烯酸丁酯与苯乙烯的配比mBA/mSt为1∶1、反应温度为80℃、反应时间为4 h时,包覆铝粉的耐酸腐蚀性能较好.运用红外光谱和扫描电镜对包覆样品进行分析表征.%To improve the corrosion resistance of the flaky aluminum powder, the flaky aluminum powder was coated by emulsion polymerization, which used butyl acrylate and styrene as monomers, sodium dodecyl sulfate as emulsifier and ammonium persulfate as initiator. The effect of the proportion of butyl acrylate and styrene, reaction temperature and reaction time on the corrosion resistance of the coated aluminum powder was examined. The results show: its acid resistance is improved obviously; the coated aluminum powder obtained under the conditions that the proportion of butyl acrylate and styrene (mBA/mSt) is 1:1, reaction temperature is 80 ℃ and reaction time is 4 h has good acid resistance. Moreover, the encapsulated samples were analyzed and characterized by Fourier transform infrared spectroscope and scanning electron microscope.

  3. A multi-module microfluidic platform for continuous pre-concentration of water-soluble ions and separation of oil droplets from oil-in-water (O/W) emulsions using a DC-biased AC electrokinetic technique.

    Science.gov (United States)

    Das, Dhiman; Phan, Dinh-Tuan; Zhao, Yugang; Kang, Yuejun; Chan, Vincent; Yang, Chun

    2017-03-01

    A novel continuous flow microfluidic platform specifically designed for environmental monitoring of O/W emulsions during an aftermath of oil spills is reported herein. Ionized polycyclic aromatic hydrocarbons which are toxic are readily released from crude oil to the surrounding water phase through the smaller oil droplets with enhanced surface area. Hence, a multi-module microfluidic device is fabricated to form ion enrichment zones in the water phase of O/W emulsions for the ease of detection and to separate micron-sized oil droplets from the O/W emulsions. Fluorescein ions in the water phase are used to simulate the presence of these toxic ions in the O/W emulsion. A DC-biased AC electric field is employed in both modules. In the first module, a nanoporous Nafion membrane is used for activating the concentration polarization effect on the fluorescein ions, resulting in the formation of stable ion enrichment zones in the water phase of the emulsion. A 35.6% amplification of the fluorescent signal is achieved in the ion enrichment zone; corresponding to 100% enrichment of the fluorescent dye concentration. In this module, the main inlet is split into two channels by using a Y-junction so that there are two outlets for the oil droplets. The second module located downstream of the first module consists of two oil droplet entrapment zones at two outlets. By switching on the appropriate electrodes, either one of the two oil droplet entrapment zones can be activated and the droplets can be blocked in the corresponding outlet.

  4. Progress in the study on graphene reinforcing emulsion polymerization rubber%石墨烯补强乳液聚合橡胶研究进展

    Institute of Scientific and Technical Information of China (English)

    蔡文婧; 梁滔; 魏绪玲; 龚光碧; 高磊; 汪冬冬

    2015-01-01

    石墨烯具有优异的力学和电学性能,是制备橡胶纳米复合材料的重要填料。介绍了石墨烯与氧化石墨烯的结构、性质和表征;重点阐述了石墨烯与氧化石墨烯补强乳聚丁苯和丁腈橡胶的原理、方法以及橡胶纳米复合材料的性能;主要通过非官能化和官能化石墨烯、石墨烯混合填料对乳聚丁苯丁腈橡胶进行补强;补强方法包括原位聚合法、溶液混合法、熔融混合法和胶乳共凝聚法;改善了橡胶的机械性能、导电导热性和气体阻隔性等性能。并对石墨烯作为橡胶补强剂的发展作了展望。%Graphene has been considered to be an important filler for the preparation of rubber nanocomposites due to its superior mechanical and electronical performances .In this review ,the structures ,properties and char‐acterizations of graphene and graphene oxide were introduced .Emphasis on the principles ,methods of graphene and graphene oxide reinforcing ESBR ,NBR .Meanwhile ,the performances of rubber nanocomposites were dis‐cussed in detail .ESBR and NBR were mainly reinforced by functional and unfunctional graphene ,graphene hy‐brid fillers .There were four methods to reinforce rubber :situ polymerization ,solution mixing ,melt mixing , latex heterocoagulation ,and then significantly improving the performances of rubber ,such as mechanical prop‐erties ,electrical conductivity ,thermal conductivity ,gas barrier properties ,and so on .In addition ,the develop‐ments of graphene as a reinforcing agent in rubber were prospected .

  5. Fluid dynamic characterization of a polymeric heart valve prototype (Poli-Valve) tested under continuous and pulsatile flow conditions.

    Science.gov (United States)

    De Gaetano, Francesco; Serrani, Marta; Bagnoli, Paola; Brubert, Jacob; Stasiak, Joanna; Moggridge, Geoff D; Costantino, Maria Laura

    2015-11-01

    Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. 2 types of Poli-Valves made of SBC and differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. A pulse duplicator designed ad hoc allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the behavior of the valve. Both types of Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by the ISO 5840 Standard. Results were compared with 5 mechanical heart valves (MHVs) and 5 tissue heart valves (THVs), currently available on the market. Based on these results, PHVs based on styrenic block copolymers, as are Poli-Valves, can be considered a promising alternative for heart valve replacement in the near future.

  6. MODELING OF THE EMULSION STABILITY USING FRACTAL DIMENSIONS

    Directory of Open Access Journals (Sweden)

    PREDRAG JOVANIĆ

    2008-09-01

    Full Text Available There are many developed strategies in the emulsion stability evaluation, for purpose of determining the life circle of emulsions. Most of them are based on the reological properties of the emulsions. There are very few which relay on the direct emulsion observations. In this paper we present the developed method for the emulsion stability evaluation by the direct observation of optical properties. As the stability quantification measure we propose the fractal dimension approach. The method is based on the measure of the emulsion transmittance properties, which are directly dependent on the emulsion stability at the moment of measurement. As the test emulsion the oil in the water emulsion was used. The system is classified as the stable emulsion and our intention was to find the moment when the emulsion starts to break. The emulsion transmittance properties were measured using an acquisition system, consisting of a CCD camera and a fast PC configuration equipped with the capturing software. The fractal dimensions were determined by the so called box counting method. The experimental emulsions were measured continuously within the period of 1200 h, from the moment of the emulsion creation. The changes of fractal dimensions were observed which indicates that the emulsion changed its state and therefore the stability during the time. Three regions of the emulsion life circle were divided according to the fractal dimensions measurement, which can be connected with the stable, unstable, and meta-stable states of the emulsion life circle. In the end, the model of the emulsion behavior was developed for the purpose of quantifying the changes in the experimental emulsion.

  7. Isorefractive high internal phase emulsion organogels for light induced reactions.

    Science.gov (United States)

    Zhang, Tao; Guo, Qipeng

    2016-03-25

    Isorefractive high internal phase emulsion (HIPE) organogels have been fabricated and investigated for light induced reactions. High transparency facilitates both the UV and visible light induced reactions within HIPE organogels. Transparent HIPE organogels are advantageous for light induced polymerizations, accelerating such polymerizations and enabling the preparation of large polyHIPE monoliths.

  8. Pickering乳液聚合制备聚苯乙烯/纳米SiO2复合微球与其性质%Properties of Polystyrene/Nano-SiO2 Composite Microspheres Prepared by Picketing Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    张卫红; 范晓东; 田威; 黄怡

    2012-01-01

    Stable Pickering emulsion was fabricated using amphiphilic nano-SiO2 particles as stabilizer.Then,two kinds of polystyrene/nano-SiO2(PS/SiO2) composite microspheres,which had different size and different morphology,were synthesized with oil-soluble azobisisobutyronitrile(AIBN) and water-soluble ammonium persulfate(APS) as initiator respectively.The possible mechanisms of Pickering emulsion polymerization initiated by different initiator were discussed.The product was characterized by means of FT-IR,multi angle laser light scattering photometer(GPC-MALLS),TGA and DSC.When AIBN was used as the initiator,the diameters of the microspheres were micron-sized(0.5 μm~2.0 μm).While the sub-micron-sized(0.1 μm~0.5 μm) microspheres were obtained by using APS as the initiator.And the weight-average molecular weight(w) of two kinds of polymer is 4.780×104 g/mol and 3.411×105 g/mol,respectively.The results of TGA and DSC indicated that the thermal properties of composite were elevated duo to the existence of nano-SiO2.%以两亲性纳米SiO2为稳定剂构筑Pickering乳液,分别采用偶氮二异丁腈(AIBN)及过硫酸铵(APS)作为引发剂引发苯乙烯单体聚合,制得了不同尺寸及形貌的聚苯乙烯/纳米SiO2(PS/SiO2)复合微球,并分析了Pickering乳液聚合的机理。通过傅里叶变换红外光谱仪(FT-IR)、凝胶渗透色谱-多角度激光光散射联用仪(GPC-MALLS)、热失重分析(TGA)及差示扫描量热仪(DSC)对产物进行了表征,结果表明,AIBN引发所得复合微球为微米级(0.5μm~2.0μm),而APS引发产物为亚微米级(0.1μm~0.5μm),两者引发所得聚合物重均分子量(-Mw)分别为4.780×10^4g/mol及3.411×10^5g/mol;复合微球的热性能因纳米SiO2的存在而得到增强。

  9. POLYMERIC SURFACTANT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    P.M. Saville; J.W. White

    2001-01-01

    Polymeric surfactants are amongst the most widespread of all polymers. In nature, proteins and polysaccharides cause self organization as a result of this surfactancy; in industry, polymeric surfactants play key roles in the food, explosives and surface coatings sectors. The generation of useful nano- and micro-structures in films and emulsions as a result of polymer amphiphilicity and the application of mechanical stress is discussed. The use of X-ray and neutron small angle scattering and reflectivity to measure these structures and their dynamic properties will be described. New results on linear and dendritic polymer surfactants are presented.

  10. MULTI-SCALE STRUCTURES IN EMULSION AND MICROSPHERE COMPLEX SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Guanghui Ma; Fangling Gong; Guohua Hu; Dongxia Hao; Rong Liu; Renwei Wang

    2005-01-01

    Multi-scale structures involved in emulsion and microsphere complex systems are presented and discussed. The stability and spatio-temporal structures of emulsions, as well as nano-structures formed on the surface of microspheres after polymerization, are affected by the molecular emulsifier/stabilizer structures and the adsorbed emulsifier/stabilizer nano-structures on the oil/water interface. The broad size distribution and variation of surface features of droplets are responsible for variations of the adsorbed emulsifier/stabilizer structures and the stability of the emulsions.On the other hand, preparation of a uniformly sized emulsion and employment of a combined emulsifier/stabilizer system can preserve the stability of the emulsions and microspheres. The above phenomena should be modeled by a multiscale method, in order to maintain the stability of individual emulsion systems and realize the desired nano-structures of microspheres by choosing adequate emulsifier/stabilizer and experimental parameters.

  11. Pickering乳液聚合制备共价键连接的磁性复合微球%Preparation of Covalently-Bonded Magnetic Microspheres by Pickering Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    杜筱; 尹德忠; 刘浩; 马荔; 贾佳

    2012-01-01

    Fe3O4/PMMA Magnetic microspheres with PMMA core and Fe3O4 nanoparticles shell were prepared by Pickering emulsion polymerization. Fe3 O4 Nanoparticles were modified sequentially by TEOS and KH570, which endowed Fe3O4 particles with reactive C=C groups on surface and suitable surface hydrophilicity for Pickering stabilization. The magnetic microspheres were characterized by grain size analyzer,optical microscopy, SEM,FTIR,TGA, and vibration sample magnetometer (VSM). The results indicated that Fe3 O4 in the shell was connected with polymer core by covalent bond which was formed by copolymerization of MMA and reactive C=C group on Fe3O4 stabilizer. The microspheres were spherical in shape,with a diameter of 15-20 /urn, a magnetic content was 4. 9% and a specific saturated magnetization intensity of 2. 38 emu · g-1 .which could be separated easily in a outer magnetic field.%以先后用TEOS和KH570改性的表面含双键的Fe3O4纳米粒子为唯一乳化剂,以甲基丙烯酸甲酯(MMA)为单体,制备了稳定的Pickering乳液,并通过Pickering乳液聚合制备了以PMMA为核、Fe3O4为壳的Fe3O4/PMMA磁性复合微球.用粒度分析仪、光学显微镜、扫描电镜、傅立叶红外光谱仪、热失重分析仪、振动样品磁强计对所制备的改性Fe3O4纳米粒子和磁性复合微球的结构、形态和性能进行了表征.结果表明:通过Fe3O4表面双键与单体的共聚,使微球表面的Fe3O4通过化学键与PMMA连接,所制备磁性复合微球粒径为15~20μm、磁含量为4.9%、比饱和磁化强度为2.38 emu · g-1,可在外磁场下方便地分离.

  12. 一种新型乳化炸药专用高分子乳化剂的研发与应用%The development and application of a new polymeric emulsifier designed for emulsion explosives

    Institute of Scientific and Technical Information of China (English)

    颜小东; 叶志文; 崔晓荣; 尤静娴

    2014-01-01

    Polyisobutylene succinic acid sorbitol ester was synthesized using polyisobutylene succinic anhydride and sorbitol as raw material .The structure of the product was characterized by infrared spectrum . To investigate the application of the emulsifier in emulsion explosives ,the emulsifying ability ,the morphology and stability of the emulsion matrix ,thermal stability and detonation performance preparaed with the product were tested .Compared to the emulsion and emulsion explosives prepared by Span‐80 and T152 as emulsifiers ,the rusults show that the emulsifying ability of the emulsifier is beween Span‐80 and T152 ,but smaller size of the emulsion matrix and longer storage period .Besides ,the detonation velocity is excellent ,the thermal stability in emulsion explosives is good .%以聚异丁烯丁二酸酐、山梨醇为原料合成聚异丁烯丁二酸山梨醇酯乳化剂,用红外光谱对产物进行结构表征。并通过与Span‐80、T152作乳化力、乳胶基质形貌、乳胶基质稳定性的对比实验及该乳化剂在乳化炸药中的热安定性和爆炸性能来考察制备的乳化剂在乳化炸药中的应用情况。结果表明,该乳化剂的乳化力介于Span‐80和T152之间,但用该乳化剂制备的乳胶基质的粒径更小、稳定性更高,制备的乳化炸药热安定性好,爆炸性能优异。

  13. Na-caseinate/oil/water systems: emulsion morphology diagrams.

    Science.gov (United States)

    Tan, Hui Lin; McGrath, Kathryn M

    2012-09-01

    The concentrated (dispersed phase 50-70 wt%) composition space of Na-caseinate, a family of milk proteins, stabilised emulsions was investigated for three different oils: soybean oil, palm olein and tetradecane with pH 6.8 phosphate buffer continuous phase. The variation of emulsion stability and microstructure were explored using static light scattering, diffusion nuclear magnetic resonance, cryo-scanning electron microscopy, rheology and the time varying macroscopic phase separation of the emulsions. For soybean oil and palm olein a rich diversity of emulsion microstructures and stabilities are realised. Five emulsion domains, each having a different microstructure and macroscopic stability have been identified within the composition space probed. For the lowest concentrations of emulsifier bridging flocculation is evident and emulsions are of low stability. Increasing Na-caseinate concentration leads to an increased stability and the existence of distinct individual oil droplets, visualised using cryo-scanning electron microscopy. Further increases in Na-caseinate concentration reduce emulsion stability due to depletion flocculation. Na-caseinate self-assembly is then initiated. At sufficiently high Na-caseinate and/or oil concentrations the continuous phase of the emulsion is a three-dimensional protein network and emulsion stability is again enhanced. At the limits of the emulsion composition space a gel-like paste is formed. The diversity of emulsion microstructure is reduced when tetradecane is the discrete phase. Na-caseinate self-assembly is limited and there is no evidence for formation of a protein network.

  14. Structure- and oil type-based efficacy of emulsion adjuvants.

    Science.gov (United States)

    Jansen, Theo; Hofmans, Marij P M; Theelen, Marc J G; Manders, Frans; Schijns, Virgil E J C

    2006-06-29

    Oil-based emulsions are well-known immunopotentiators for inactivated, "killed" vaccines. We addressed the relationship between emulsion structure and levels of in vivo antibody formation to inactivated New Castle Disease virus (NDV) and Infectious Bronchitis virus (IBV) as antigens in 3-week-old chickens. The use of a polymeric emulsifier allowed for direct comparison of three types of emulsions, water-in-oil (W/O), oil-in-water (O/W) and W/O-in-water (W/O/W), while maintaining an identical content of components for each vehicle. They were prepared with either non-metabolizable, mineral oil or metabolizable, Miglyol 840. In addition, we assessed the inherent release capacity of each emulsion variant in vitro. Remarkably, we noted that W/O-type emulsions induced the best immune responses, while they released no antigen during 3 weeks. In general, mineral oil vaccines showed superior efficacy compared to Miglyol 840-based vaccines.

  15. Non-aqueous Isorefractive Pickering Emulsions

    OpenAIRE

    Thompson, K. L.; Lane, J.A.; Derry, M.J.; Armes, S. P.

    2015-01-01

    Non-aqueous Pickering emulsions of 16–240 μm diameter have been prepared using diblock copolymer worms with ethylene glycol as the droplet phase and an n-alkane as the continuous phase. Initial studies using n-dodecane resulted in stable emulsions that were significantly less turbid than conventional water-in-oil emulsions. This is attributed to the rather similar refractive indices of the latter two phases. By utilizing n-tetradecane as an alternative oil that almost precisely matches the re...

  16. Characteristics and behavior of emulsion at nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Gonda, K.; Nemoto, T.; Oka, K.

    1982-05-01

    The characteristics and behavior of the emulsion formed in mixer-settlers during nuclear fuel reprocessing were studied with the dissolver solution of spent fuel burned up to 28,000 MWd/MTU and a palladium colloidal solution, respectively. The emulsion was observed to be oil in water where nonsoluble residues of spent fuel were condensed as emulsifiers. Emulsion formed at interfaces in the settler showed electric conductivity due to continuity of the aqueous phase of the emulsion and viscosity due to the creamy state of the emulsion. The higher the palladium particle concentration was, the larger the amount of emulsion formed. This result agreed well with experience obtained in the Tokai Reprocessing Plant operation that both nonsoluble residues and emulsion formation increased remarkably on fuels in which burnup exceeded 20 000 MWd/MTU.

  17. Emulsifier for water-in-oil emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Weete, J.D.; Griffith, G.L.

    1990-07-24

    This patent describes a water-in-oil emulsion. It comprises: a continuous oil phase, a discontinuous aqueous phase, and an emulsion stabilizing amount of a thermally altered lecithin composition which has been prepare by heating lecithin at a temperature in the range of from about 100{degrees}C, to about 250{degrees}C, for a period of time ranging from about 15 to about 480 minutes.

  18. Encapsulation of aluminum phosphate nanoparticles (AiPO{sub 4}) functionalized with 3-mercapto-propyl trimethoxy-silane (MPTMS) by mini emulsion polymerization; Encapsulacao de nanoparticulas de fosfato de aluminio (AiPO{sub 4}) funcionalizadas com trimetoxsilano propil metacrilato (MPTMS) vip polimerizacao em miniemulsao

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Leticia A. da; Machado, Ricardo A.F.; Araujo, Pedro H.H. de; Sayer, Claudia, E-mail: leticia@enq.ufsc.br [Universidade Federal de Santa Catarina - UFSC, Florianopolis, SC (Brazil); Sudol, Edward D.; El-Aasser, Mohamed S. [Lehigh University, Bethlehem, Pensilvania (United States)

    2011-07-01

    This work aims the use of the mini emulsion polymerization process for the attainment of a copolymer latex made of styrene butyl {eta}-acrylate (50/50) in the presence of 3 wt.% of AlPO{sub 4} with the surface chemically modified with 3-Mercapto-Propyl trimethoxy-Silane (MPTMS) in three different concentrations (5, 10 and 20 wt.% based on AlPO{sub 4}). The confirmation of the AlPO{sub 4} functionalization was made by FTIR. The encapsulation efficiency was analyzed through the density gradient column, energy dispersive X-ray and transmission electron microscopy and the average particles size and its distribution by capillary hydrodynamic fractionation. Results had shown that it was possible to encapsulate the AlPO{sub 4} and that the sample functionalized with 20 wt% of MPTMS resulted in a latex with greater density and a weight average particle size of (Dw) 116 nm. (author)

  19. Detection of coalescing agents in water-borne latex emulsions using an environment sensitive fluorescent probe

    NARCIS (Netherlands)

    Raja, T.N.; Brouwer, A.M.; Biemans, K.; Nabuurs, T.; Tennebroek, R.

    2010-01-01

    In this paper we report the determination of partitioning of coalescing agents (organic co-solvents) in water-borne latex emulsions by means of a fluorescence method. An environment-sensitive fluorescent probe 1 was copolymerized via emulsion polymerization. The presence of organic co-solvents insid

  20. Rheological characterization of polysaccharide-surfactant matrices for cosmetic O/W emulsions.

    Science.gov (United States)

    Bais, D; Trevisan, A; Lapasin, R; Partal, P; Gallegos, C

    2005-10-15

    Rheometrical techniques can be profitably used for polysaccharide matrices in order to evaluate their suitability for the preparation of stable cosmetic O/W emulsions. In particular, the rheological properties of aqueous scleroglucan systems were investigated under continuous and oscillatory shear conditions in a polymer concentration range (0.2-1.2% w/w) embracing the sol/gel transition. The effects due to the addition of two different surfactants (up to 10% w/w) were examined at constant polymer concentration (0.4% w/w). The selected additives are a nonionic polymeric siliconic surfactant (dimethicone copolyol) and a cationic surfactant (tetradecyltrimethylammonium bromide), respectively. Polysaccharide-surfactant interactions leading to complex formation were detected also through rheology. The combined action of both nonionic and cationic surfactants in the polymer solution was examined at two different surfactant concentration levels (5 and 10% w/w), demonstrating the beneficial effects produced on the mechanical properties of the polymer matrix by the coexistence of both surfactants. Such beneficial effects are confirmed by the stability and rheology shown by the emulsions prepared. In this way, the results point out the good agreement between the rheology of the continuous phase and the final characteristics of the emulsion obtained.

  1. The interactions between oil droplets and gel matrix affect the lubrication properties of sheared emulsion-filled gels

    NARCIS (Netherlands)

    Chojnicka, A.; Sala, G.; Kruif, de C.G.; Velde, van de F.

    2009-01-01

    In this work the lubrication behaviour of emulsions, gels, and emulsion-filled gels was studied in relation to their composition and structure. It was found that emulsions had much lower friction coefficients than their continuous phases. Emulsions with 40 wt% oil had the same friction coefficient a

  2. Synthetic Polymers at Interfaces: Monodisperse Emulsions Multiple Emulsions and Liquid Marbles

    Science.gov (United States)

    Sun, Guanqing

    The adsorption of polymeric materials at interfaces is an energetically favorable process which is investigated in much diversified fields, such as emulsions, bubbles, foams, liquid marbles. Pickering emulsion, which is emulsion stabilized by solid particles has been investigated for over one century and preparation of Pickering emulsion with narrow size distribution is crucial for both the theoretical study of the stabilization mechanism and practical application, such as templated fabrication of colloidosomes. The precise control over the size and functionality of polymer latices allows the preparation of monodisperse Pickering emulsions with desired sizes through SPG membrane emulsification at rather rapid rate compared to microfludic production. Double or multiple emulsions have long been investigated but its rapid destabilization has always been a major obstacle in applying them into practical applications. The modern living polymerization techniques allow us to prepare polymers with designed structure of block copolymers which makes it possible to prepare ultra-stable multiple emulsions. The precise tuning of the ratio of hydrophobic part over the hydrophilic can unveil the stabilization mechanism. Liquid marble is a new type of materials of which liquid droplets are coated by dry particles. The coating of an outer layer of dry particles renders the liquid droplets non-sticky at solid surface which is useful in transportation of small amount of liquid without leakage at extreme low friction force. The property of liquid marbles relies largely on the stabilizers and the drying condition of polymeric latices is shown to have great influence on the property of liquid marbles. Firstly, an introduction to the interfacial and colloidal science with special attention to topics on emulsions, multiple emulsion and liquid marbles is given in Chapter 1. The unique features of an interface and a discussion on the definition of colloids are introduced prior to the

  3. Surface modification and characterization of nanometer TiO2 for nanometer styrene-acrylate emulsion polymerization%用于合成纳米苯丙乳液的纳米TiO2表面改性及表征

    Institute of Scientific and Technical Information of China (English)

    邵谦; 王成国; 朱云峰; 葛圣松

    2006-01-01

    A process for modification of nanometer TiO2 by silane coupling agent was studied. The structure and the dispersibility of modified TiO2 were investigated by FTIR and TEM. The results showed that a chemical coupling reaction could take place between the coupling agent and TiO2 surface. As a result, the coupling agent was absorbed chemically on the surface of nanometer TiO2 to improve its dispersibility and stability in organics. Nanometer TiO2/styrene-acrylate composite emulsion was prepared by in-situ polymerization with modified TiO2. The TEM photograph indicated that the composite exhibited a core-shell structure with nanometer TiO2 as core and organic polymer as shell. The properties of composite emulsion were determined: water resistance of coating film of latex was 120h; hardness of coating film of latex was H grade, which was obviously superior to normal styrene-acrylate emulsion without nano-particles. Furthermore, this kind of nano-emulsion also owns perfect antibacterial characteristic. It could be used to prepare nanometer waterborne coatings.%研究了利用硅烷偶联剂改性纳米TiO2的方法,并通过FTIR、TEM等手段表征化学改性产物的结构和改性后纳米二氧化钛的分散性,结果表明偶联剂与二氧化钛表面发生化学偶联反应,使二氧化钛表面被偶联剂包覆,从而使二氧化钛改性产物在有机物中具有良好的分散性能.通过TEM分析用改性后的纳米TiO2原位合成的纳米TiO2/苯丙乳液复合体系具有以纳米TiO2粒子为核,以聚合物为壳的核壳结构,该乳液涂膜的耐水性达120h不泛白,硬度为H级,明显优于非纳米苯丙乳液,且具有很好的抑菌作用,可用于制备纳米水性涂料.

  4. Edge-modified amphiphilic Laponite nano-discs for stabilizing Pickering emulsions.

    Science.gov (United States)

    Yang, Ying; Liu, Zhi; Wu, Dayong; Wu, Man; Tian, Ye; Niu, Zhongwei; Huang, Yong

    2013-11-15

    We investigated the effect of amphiphilic Laponite nano-discs, which were edge-modified by hydrophobic chains, on the properties of Pickering emulsions and Pickering emulsions polymerization. Comparing to unmodified Laponites, these amphiphilic nano-discs can greatly reduce the surface tension, resulting in very stable Pickering emulsions. These particles uniquely combine the Pickering effect with amphiphilic properties similar to the surfactant. Taking advantage of these amphiphilic Pickering emulsifiers, miniemulsion polymerization of styrene was performed. Homogeneous polystyrene nanoparticles with size around 150 nm could thus be prepared.

  5. A study of hydrate formation and dissociation from high water cut emulsions and the impact on emulsion inversion

    Energy Technology Data Exchange (ETDEWEB)

    Greaves, D.P.; Boxall, J.A.; Mulligan, J.; Dendy Sloan, E.; Koh, C.A. [Colorado School of Mines, Golden, CO (United States). Dept. of Chemical Engineering, Center for Hydrate Research

    2008-07-01

    The challenges facing the petroleum industry regarding clathrate hydrate formation were discussed, with particular reference to the costly and dangerous pipeline blocking plugs that form upon hydrate accumulation and agglomeration. Although a variety of inhibitors are used to prevent hydrate plug formation, they are not designed for high water content production. As oil and gas are produced from less profitable or older wells, there is a greater probability of higher water cuts. Therefore, this study focused on methane hydrate formation and dissociation from these high water content (greater than 60 per cent volume) emulsions of water-in-oil (W/O) and oil-in-water (O/W). At high water cuts, the system can quickly agglomerate with hydrate formation, while dissociation can lead to a significant change in the emulsion type. Although inhibition can be costly at high water cuts, it must be considered because of the risk of immediate agglomeration and plug formation with hydrates. In this study, the hydrate formation and dissociation from W/O emulsions destabilized the emulsion, with the final emulsion formulation favouring a water continuous state following re-emulsification. After dissociation, the W/O emulsion formed a multiple o/W/O emulsion or inverted at even higher water cuts, forming an O/W emulsion with 68 per cent water volume. In contrast, hydrate formation and dissociation from O/W emulsions with more than 71 per cent water volume stablized the O/W emulsion. 24 refs., 13 figs.

  6. Encapsulation of titanium dioxide nanoparticles in PLA microspheres using supercritical emulsion extraction to produce bactericidal nanocomposites

    Science.gov (United States)

    Campardelli, R.; Della Porta, G.; Gomez, V.; Irusta, S.; Reverchon, E.; Santamaria, J.

    2013-10-01

    In this work, PLA microparticles containing TiO2 (anatase) nanoparticles have been produced using the Continuous Supercritical Emulsion Extraction technique (SEE-C). A stabilized anatase colloidal suspension (15 ± 5 nm) in ethanol aqueous solution was obtained by precipitation from solutions of titanium alkoxides and directly used as the water internal phase of a water-in-oil in water double emulsion or suspended as a powder in the organic phase of a solid-in-oil in water emulsion. Micro- (0.9 ± 0.5 μm) and submicro-particles (203 ± 40 nm) have been produced, with TiO2 nominal loadings of 1.2, 2.4, and 3.6 wt%. High TiO2 encapsulation efficiencies up to about 90 % have been obtained. PLA/TiO2 particles have been characterized by TEM and XPS to investigate the dispersion of the metal oxide in the polymeric matrix. The photo-assisted bactericidal activity of TiO2-containing microparticles against a biofilm-forming strain of Staphylococcus aureus was investigated in specific assays under UV light. Pure TiO2 nanoparticles and PLA/TiO2 particles showed the same bactericidal activity.

  7. Inorganic/organic hybrid microcapsules: melamine formaldehyde-coated Laponite-based Pickering emulsions.

    Science.gov (United States)

    Williams, Mark; Olland, Birte; Armes, Steven P; Verstraete, Pierre; Smets, Johan

    2015-12-15

    A facile synthesis route to novel inorganic/organic hybrid microcapsules is reported. Laponite nanoparticles are surface-modified via electrostatic adsorption of Magnafloc, an amine-based polyelectrolyte allowing the formation of stable oil-in-water Pickering emulsions. Hybrid microcapsules can be subsequently prepared by coating these Pickering emulsion precursors with dense melamine formaldehyde (MF) shells. Employing a water-soluble polymeric stabiliser, poly(acrylamide-co-sodium acrylate) leads to stable hybrid microcapsules that survive an alcohol challenge and the ultrahigh vacuum conditions required for SEM studies. Unfortunately, the presence of this copolymer also leads to secondary nucleation of excess MF latex particles in the aqueous continuous phase. However, since the Magnafloc is utilised at submonolayer coverage when coating the Laponite particles, the nascent cationic MF nanoparticles can deposit onto anionic surface sites on the Laponite, which removes the requirement for the poly(acrylamide-co-sodium acrylate) component. Following this electrostatic adsorption, the secondary amine groups on the Magnafloc chains can react with the MF, leading to highly robust cross-linked MF shells. The absence of the copolymer leads to minimal secondary nucleation of MF latex particles, ensuring more efficient deposition at the surface of the emulsion droplets. However, the MF shells appear to become more brittle, as SEM studies reveal cracking on addition of ethanol.

  8. Encapsulation of titanium dioxide nanoparticles in PLA microspheres using supercritical emulsion extraction to produce bactericidal nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Campardelli, R., E-mail: rcampardelli@unisa.it; Della Porta, G. [University of Salerno, Department of Industrial Engineering (Italy); Gomez, V.; Irusta, S. [University of Zaragoza, Aragon Institute of Nanoscience (INA) (Spain); Reverchon, E., E-mail: ereverchon@unisa.it [University of Salerno, Department of Industrial Engineering (Italy); Santamaria, J., E-mail: jesus.santamaria@unizar.es [University of Zaragoza, Aragon Institute of Nanoscience (INA) (Spain)

    2013-10-15

    In this work, PLA microparticles containing TiO{sub 2} (anatase) nanoparticles have been produced using the Continuous Supercritical Emulsion Extraction technique (SEE-C). A stabilized anatase colloidal suspension (15 {+-} 5 nm) in ethanol aqueous solution was obtained by precipitation from solutions of titanium alkoxides and directly used as the water internal phase of a water-in-oil in water double emulsion or suspended as a powder in the organic phase of a solid-in-oil in water emulsion. Micro- (0.9 {+-} 0.5 {mu}m) and submicro-particles (203 {+-} 40 nm) have been produced, with TiO{sub 2} nominal loadings of 1.2, 2.4, and 3.6 wt%. High TiO{sub 2} encapsulation efficiencies up to about 90 % have been obtained. PLA/TiO{sub 2} particles have been characterized by TEM and XPS to investigate the dispersion of the metal oxide in the polymeric matrix. The photo-assisted bactericidal activity of TiO{sub 2}-containing microparticles against a biofilm-forming strain of Staphylococcus aureus was investigated in specific assays under UV light. Pure TiO{sub 2} nanoparticles and PLA/TiO{sub 2} particles showed the same bactericidal activity.

  9. RETRACTED: Size-controlled spherical polymer nanoparticles: synthesis with tandem acoustic emulsification followed by soap-free emulsion polymerization and one-step fabrication of colloidal crystal films of various colors.

    Science.gov (United States)

    Hirai, Yuki; Nakabayashi, Koji; Kojima, Maya; Atobe, Mahito

    2014-11-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article was retracted at the request of the Editor. The above paper is essentially a duplicate of an original Article in “Size-Controlled Synthesis of Polymer Nanoparticles with Tandem Acoustic Emulsification Followed by Soap-Free Emulsion Polymerization” ACS Macro Lett., 2013, 2 (6), pp 482–484, 10.1021/mz4001817. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Synthesis of Ammonium Polyacrylate by Inverse Emulsion Polymerization for Red Mud Settlement and Its Corresponding Performance Study%赤泥沉降用聚丙烯酸铵的反相乳液聚合及其性能研究

    Institute of Scientific and Technical Information of China (English)

    乐发垫; 陈文汨

    2016-01-01

    The ammonium polyacrylate emulsion was prepared by using new Gemini polymeric emulsifier together with OP-10 and oil phase Isopar M. The effects on monomer conversion and intrinsic viscosity of polymer by factors of HLB value, dosage of initiator, concentration of monomer, addition of EDTA, polymerization temperature and time were investigated. Results showed that under the following optimum polymerization conditions, including the mass fraction of monomer at 45%, HLB value at 8, the concentration of initiator ( V50) accounting for 0.15% of monomer concentration, the concentration of EDTA at 0.3%, the polymerization temperature of 50 ℃ and polymerization time of 6 h, the mass ratio of oil phase to water phase was 1∶3 and the monomer conversion rate reached 97. 44% with intrinsic viscosity at 885.45 mL/g, showing a good performance in red mud settlement.%采用新型Gemini乳化剂与OP⁃10复配, Isopar M为油相合成聚丙烯酸铵乳液,研究了HLB值、引发剂用量、单体浓度、EDTA添加量、聚合温度与时间等因素对单体转化率及聚合物特性黏度的影响。结果表明:控制单体的质量分数为45%,在HLB值为8、引发剂( V50)浓度占单体浓度的0.15%、EDTA浓度为0.3%、聚合温度50℃、时间6 h条件下,合成效果最佳。在最佳条件下,乳液的油水比达到1∶3,单体转化率达到97.44%,特性粘度为885.45 mL/g,且赤泥沉降效果良好。

  11. Thermodynamically Stable Pickering Emulsions

    NARCIS (Netherlands)

    Sacanna, S.; Kegel, W.K.; Philipse, A.P.

    2007-01-01

    We show that under appropriate conditions, mixtures of oil, water, and nanoparticles form thermodynamically stable oil-in-water emulsions with monodisperse droplet diameters in the range of 30–150 nm. This observation challenges current wisdom that so-called Pickering emulsions are at most metastabl

  12. Emulsion Science Basic Principles

    CERN Document Server

    Leal-Calderon, Fernando; Schmitt, Véronique

    2007-01-01

    Emulsions are generally made out of two immiscible fluids like oil and water, one being dispersed in the second in the presence of surface-active compounds.They are used as intermediate or end products in a huge range of areas including the food, chemical, cosmetic, pharmaceutical, paint, and coating industries. Besides the broad domain of technological interest, emulsions are raising a variety of fundamental questions at the frontier between physics and chemistry. This book aims to give an overview of the most recent advances in emulsion science. The basic principles, covering aspects of emulsions from their preparation to their destruction, are presented in close relation to both the fundamental physics and the applications of these materials. The book is intended to help scientists and engineers in formulating new materials by giving them the basics of emulsion science.

  13. 40 CFR 428.20 - Applicability; description of the emulsion crumb rubber subcategory.

    Science.gov (United States)

    2010-07-01

    ... emulsion crumb rubber subcategory. 428.20 Section 428.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS RUBBER MANUFACTURING POINT SOURCE CATEGORY Emulsion Crumb Rubber Subcategory § 428.20 Applicability; description of the emulsion crumb rubber...

  14. Preparation of Pickering double emulsions using block copolymer worms.

    Science.gov (United States)

    Thompson, Kate L; Mable, Charlotte J; Lane, Jacob A; Derry, Mathew J; Fielding, Lee A; Armes, Steven P

    2015-04-14

    The rational formulation of Pickering double emulsions is described using a judicious combination of hydrophilic and hydrophobic block copolymer worms as highly anisotropic emulsifiers. More specifically, RAFT dispersion polymerization was utilized to prepare poly(lauryl methacrylate)-poly(benzyl methacrylate) worms at 20% w/w solids in n-dodecane and poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate)-poly(benzyl methacrylate) worms at 13% w/w solids in water by polymerization-induced self-assembly (PISA). Water-in-oil-in-water (w/o/w) double emulsions can be readily prepared with mean droplet diameters ranging from 30 to 80 μm using a two-stage approach. First, a w/o precursor emulsion comprising 25 μm aqueous droplets is prepared using the hydrophobic worms, followed by encapsulation within oil droplets stabilized by the hydrophilic worms. The double emulsion droplet diameter and number of encapsulated water droplets can be readily varied by adjusting the stirring rate employed during the second stage. For each stage, the droplet volume fraction is relatively high at 0.50. The double emulsion nature of the final formulation was confirmed by optical and fluorescence microscopy studies. Such double emulsions are highly stable to coalescence, with little or no change in droplet diameter being detected over storage at 20 °C for 10 weeks as judged by laser diffraction. Preliminary experiments indicate that the complementary o/w/o emulsions can also be prepared using the same pair of worms by changing the order of homogenization, although somewhat lower droplet volume fractions were required in this case. Finally, we demonstrate that triple and even quadruple emulsions can be formulated using these new highly anisotropic Pickering emulsifiers.

  15. Preparation of drug nanoparticles by emulsion evaporation method

    Energy Technology Data Exchange (ETDEWEB)

    Le Thi Mai Hoa; Dang Mau Chien [Laboratory for Nanotechnology, Vietnam National University of Ho Chi Minh City, 6 Community, Linh Trung Ward, Thu Duc District, Ho Chi Minh City (Viet Nam); Nguyen Tai Chi; Nguyen Minh Triet; Le Ngoc Thanh Nhan [Faculty of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, 41 Dinh Tien Hoang, Ben Nghe Ward, 1 District, Ho Chi Minh City (Viet Nam)], E-mail: ltmhoa@vnuhcm.edu.vn

    2009-09-01

    Polymeric drug nanoparticles were prepared by emulsion solvent evaporation method. In this study, prepared the polymeric drug nanoparticles consist of ketoprofen and Eudragit E 100. The morphology structure was investigated by scanning electron microscopy (SEM). The interactions between the drug and polymer were investigated by Fourier transform infrared spectroscopy (FTIR). The size distribution was measured by means of Dynamic Light Scattering. The nanoparticles have an average size of about 150 nm. The incorporation ability of drugs in the polymeric nanoparticles depended on the integration between polymer and drug as well as the glass transition temperature of the polymer.

  16. Influences of Electrolytes on the Soap-free Emulsion Copolymerization of St-MMA-AA

    Institute of Scientific and Technical Information of China (English)

    Rong Long LI; Cheng You KAN; Yi DU; Ze Ping LI

    2006-01-01

    Monodisperse functional polymer microspheres with different particle size and with clean surface were prepared by batch soap-free emulsion polymerization of styrene, methyl methacrylate and acrylic acid in the presence of salts, and the influences of type and amount of electrolytes on polymerization process and particle morphology were investigated. Results showed that there was a critical concentration for different electrolyte to make polymerization process and the resultant emulsion stable, and the particle size increased with the increase of electrolyte concentration. The effect of metal ions was Ca2+>>K+>Na+>Li+, and the effect of haloids was Br->Cl->F-.

  17. MODELING PARTICLE SIZE DISTRIBUTION IN HETEROGENEOUS POLYMERIZATION SYSTEMS USING MULTIMODAL LOGNORMAL FUNCTION

    Directory of Open Access Journals (Sweden)

    J. C. Ferrari

    Full Text Available Abstract This work evaluates the usage of the multimodal lognormal function to describe Particle Size Distributions (PSD of emulsion and suspension polymerization processes, including continuous reactions with particle re-nucleation leading to complex multimodal PSDs. A global optimization algorithm, namely Particle Swarm Optimization (PSO, was used for parameter estimation of the proposed model, minimizing the objective function defined by the mean squared errors. Statistical evaluation of the results indicated that the multimodal lognormal function could describe distinctive features of different types of PSDs with accuracy and consistency.

  18. In-Water and Neat Batch and Continuous-Flow Direct Esterification and Transesterification by a Porous Polymeric Acid Catalyst

    Science.gov (United States)

    Baek, Heeyoel; Minakawa, Maki; Yamada, Yoichi M. A.; Han, Jin Wook; Uozumi, Yasuhiro

    2016-05-01

    A porous phenolsulphonic acid—formaldehyde resin (PAFR) was developed. The heterogeneous catalyst PAFR was applied to the esterification of carboxylic acids and alcohols, affording the carboxylic acid esters in a yield of up to 95% where water was not removed from the reaction mixture. Surprisingly, the esterification in water as a solvent proceeded to afford the desired esters in high yield. PAFR provided the corresponding esters in higher yield than other homogeneous and heterogeneous catalysts. The transesterification of alcohols and esters was also investigated by using PAFR, giving the corresponding esters. PAFR was applied to the batch-wise and continuous-flow production of biodiesel fuel FAME. The PAFR-packed flow reactor that was developed for the synthesis of carboxylic acids and FAME worked for four days without loss of its catalytic activity.

  19. Research and application progress of magnetic polymeric microspheres via monomer polymerization method%磁性高分子复合微球的研究与应用进展

    Institute of Scientific and Technical Information of China (English)

    林计志; 吴波; 邓慧娟; 张建安; 吴明元; 吴庆云; 杨建军

    2012-01-01

    Preparation of magnetic polymeric microspheres via monomer polymerization methods was reviewed, including soap-free emulsion polymerization, seeded emulsion polymerization, Pickering emulsion polymerization, miniemulsion polymerization, inverse emulsion polymerization, in situ emulsion polymerization, and dispersion polymerization to prepare non-hollow magnetic polymeric microspheres. The fabrication methods of magnetic hollow polymeric microspheres were also introduced. The applications of these materials in the fields of immobilized enzyme, purification of DNA, and carrier of drugs were described. Finally, the future trends of magnetic polymeric microspheres were prospected.%论述了单体聚合法制备磁性高分子复合微球的研究近况,主要介绍了非中空磁性高分子复合微球的无皂乳液聚合、种子乳液聚合、Pickering乳液聚合、细乳液聚合、反相乳液聚合、原位乳液聚合及分散聚合等制备方法及中空微球的设计与制备方法.概述了磁性高分子复合微球在固定化酶、DNA分离提纯、药物载体等方面的应用.最后对磁性高分子复合微球的发展趋势进行了展望.

  20. Polymeric microspheres

    Science.gov (United States)

    Walt, David R.; Mandal, Tarun K.; Fleming, Michael S.

    2004-04-13

    The invention features core-shell microsphere compositions, hollow polymeric microspheres, and methods for making the microspheres. The microspheres are characterized as having a polymeric shell with consistent shell thickness.

  1. Preparation of poly(vinyl alcohol)-grafted graphene oxide/poly(vinyl alcohol) nanocomposites via in-situ low-temperature emulsion polymerization and their thermal and mechanical characterization

    Science.gov (United States)

    Zhang, Shengchang; Liu, Pengqing; Zhao, Xiangsen; Xu, Jianjun

    2017-02-01

    An in-situ polymerization combined with chemical grafting modification method for preparing Poly(vinyl alcohol)-grafted graphene oxide/Poly(vinyl alcohol) (PVA-g-GO/PVA) nanocomposites was reported. Firstly, Poly(vinyl acetate)-grafted graphene oxide/Poly(vinyl acetate) nanocomposites were prepared, and then the PVA-g-GO/PVA nanocomposites could be obtained through alcoholysis reaction. X-ray photoelectron spectrometer and fourier-transform infrared spectrometer confirmed that the PVAc or PVA chains were successfully grafted to GO sheets during in-situ polymerization and alcoholysis. And the results from transmission electron microscopy, scanning electron microscopy and X-ray diffraction showed that the well compatibility and homogenous dispersion of PVA-g-GO in PVA matrix could be achieved. Differential scanning calorimetric, thermogravimetry analysis and tensile test were employed to study the thermal and mechanical properties of the PVA-g-GO/PVA nanocomposites. The results indicated that a 53% improvement of tensile strength and a 36% improvement of Young's modulus were achieved by addition of 0.5 wt% of GO sheets. And the glass transition temperature of PVA-g-GO/PVA nanocomposites was increased, and their thermal stability and crystallization degree were both decreased. Due to well dispersion of fillers and strong interfacial interactions at the filler-matrix interface, in-situ polymerization combined with chemical grafting modification was a good choice to prepare graphene/PVA nanocomposite with excellent mechanical properties.

  2. Emulsions inside Gargamelle

    CERN Multimedia

    1978-01-01

    A feasibility test was made with a 2.5 litre emulsion stack installed within the chamber. The stack was contained in a thermally insulated aluminium alloy pressure vessel (photo). See Annual Report 1978 p. 79 Fig. 5.

  3. Electron-beam cured emulsion pressure-sensitive adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Mallya, P.; Plamthottam, S.S.; Ozari, Y.

    1993-08-03

    A cured pressure-sensitive adhesive is described which comprises a branched chain emulsion polymer having a glass transition temperature of at least 20 C below the use temperature, and formed by emulsion polymerization of at least one first monomer which, when homo polymerized, has a glass transition temperature less than [minus]25 C and at least one second monomer which, when homo polymerized, has a glass transition temperature greater than [minus]25 C., and said emulsion polymer being cured in the presence of from about 0.2 to about 10% by weight based on the weight of the emulsion-polymer of a multifunctional additive and exposure to electron beam radiation at a dosage of up to 100 kGy and sufficient to provide a 70 C shear of at least 10 kiloseconds and a 180 C peel of at least about 250 N/m, and a loop tack of at least about 200 N/m at a coat weight of from about 40 to 60 g/m[sup 2].

  4. Preparation, characterization, and in vitro gastrointestinal digestibility of oil-in-water emulsion-agar gels.

    Science.gov (United States)

    Wang, Zheng; Neves, Marcos A; Kobayashi, Isao; Uemura, Kunihiko; Nakajima, Mitsutoshi

    2013-01-01

    Soybean oil-in-water (O/W) emulsion-agar gel samples were prepared and their digestibility evaluated by using an in vitro gastrointestinal digestion model. Emulsion-agar sols were obtained by mixing the prepared O/W emulsions with a 1.5 wt % agar solution at 60 °C, and their subsequent cooling at 5 °C for 1 h formed emulsion-agar gels. Their gel strength values increased with increasing degree of polymerization of the emulsifiers, and the relative gel strength increased in the case of droplets with an average diameter smaller than 700 nm. Flocculation and coalescence of the released emulsion droplets depended strongly on the emulsifier type; however, the emulsifier type hardly affected the ζ-potential of emulsion droplets released from the emulsion-agar gels during in vitro digestion. The total FFA content released from each emulsion towards the end of the digestion period was nearly twice that released from the emulsion-agar gel, indicating that gelation of the O/W emulsion may have delayed lipid hydrolysis.

  5. Magnetoresistive emulsion analyzer.

    Science.gov (United States)

    Lin, Gungun; Baraban, Larysa; Han, Luyang; Karnaushenko, Daniil; Makarov, Denys; Cuniberti, Gianaurelio; Schmidt, Oliver G

    2013-01-01

    We realize a magnetoresistive emulsion analyzer capable of detection, multiparametric analysis and sorting of ferrofluid-containing nanoliter-droplets. The operation of the device in a cytometric mode provides high throughput and quantitative information about the dimensions and magnetic content of the emulsion. Our method offers important complementarity to conventional optical approaches involving ferrofluids, and paves the way to the development of novel compact tools for diagnostics and nanomedicine including drug design and screening.

  6. Enhancing saltiness in emulsion based foods

    Directory of Open Access Journals (Sweden)

    Lad Mita

    2012-07-01

    Full Text Available Abstract Background The concept of enhancing saltiness perception in emulsions and a liquid food formulated with the emulsions (ambient vegetable soup through increasing salt concentration in the continuous phase while retaining the fat content of the (aqueous continuous product was evaluated. This was accomplished by increasing the droplet phase volume using duplex emulsion technology. Viscosity and droplet size distribution was measured. Saltiness evaluation was based on simple paired comparison testing (2-Alternate Forced Choice tests, BS ISO 5495:2007. Results Single and duplex emulsions and emulsion-based products had comparable mean oil droplet diameters (25 to 30 μm; however, viscosity of the duplex emulsion systems was considerably higher. Sensory assessment of saltiness of emulsion pairs (2AFC indicated duplex technology enhanced saltiness perception compared to a single emulsion product at the same salt content (6.3 g/100 g in both simple emulsions and the formulated food product (P = 0.0596 and 0.0004 respectively although assessors noted the increased viscosity of the duplex systems. The formulated food product also contained pea starch particles which may have aided product mixing with saliva and thus accelerated tastant transport to the taste buds. Lowering salt content in the duplex systems (to levels of aqueous phase salt concentration similar to the level in the single systems resulted in duplex systems being perceived as less salty than the single system. It appears that the higher viscosity of the duplex systems could not be “overruled” by enhanced mixing through increased droplet phase volume at lowered salt content. Conclusions The results showed that salt reduction may be possible despite the added technology of duplex systems increasing the overall measured viscosity of the product. The changes in viscosity behavior impact mouthfeel, which may be exploitable in addition to the contribution towards salt

  7. Design and development of oral nanoparticulated insulin in multiple emulsion.

    Science.gov (United States)

    Siddhartha, T Venkata; Senthil, V; Kishan, Ilindra Sai; Khatwal, Rizwan Basha; Madhunapantula, SubbaRao V

    2014-01-01

    The present research aimed at developing an injection-free nanoparticulated formulation in multiple emulsion form, for oral delivery of insulin, which otherwise undergoes degradation in the gastric environment if administered orally. Insulin-polymeric nanoparticles were prepared using layer by layer (LbL) adsorption method and incorporated into an emulsion to form a nanoparticulated multiple emulsion. Using 0.6 M sodium chloride, the insulin nanoaggregates of 300-400 nm size were obtained about a yield of 94%. The characteristics of a representative nanoparticle were as follows: particle size - 391.9±0.41 nm, polydispersity index -0.425, zeta potential- +20.6 mv, encapsulation efficiency- 86.7±1.42% and percentage entrapment efficiency of the insulin-polymeric nanoparticles in the inner aqueous phase of emulsion was 84.6%. The FT-IR analysis confirms that there were no drug interactions with the polymers. Stability analysis carried out for 3 months at 8-40 °C, showed only minor changes at the end period. The release kinetics of the nanoparticulated multiple emulsion at pH 7.4 followed first order kinetics and obeyed the Fickian law. However, at pH 2.0 the release kinetics from nanoparticulated multiple emulsion followed zero order kinetics without obeying to the Fickian law. In conclusion, our data demonstrate that the nanoparticulated multiple emulsion formulation has good release characteristics and imparted a tolerable protection for insulin at different pH conditions, which may be exploited for oral administration.

  8. Effects of continuous tube feeding of dietary fat emulsions on eicosanoid production and on fatty acid composition during an acute septic shock in rats.

    Science.gov (United States)

    Utsunomiya, T; Chavali, S R; Zhong, W W; Forse, R A

    1994-10-06

    The effects of a short-term (5 days) continuous intragastric tube feeding of diets containing n - 6 polyunsaturated fatty acids (PUFA) from safflower oil (SO) or n - 3 PUFA from menhaden oil (MO) on the production of proinflammatory mediators, and on the number of animals surviving after an intravenous injection of lipopolysaccharide (LPS) were investigated in rats. The phospholipid fatty acid composition of cell membranes from several organs and of plasma were also analyzed. No marked differences in the number of animals surviving or in the production of tumor necrosis factor-alpha were observed between the 2 groups of animals. However, 90 min after LPS exposure the plasma levels of prostaglandin (PG) E2 and 6-keto-PGF1 alpha decreased significantly (40% and 60%, respectively) for the group of rats fed MO diet compared to those fed SO diet (P < 0.05). Following continuous infusion of liquid MO diet, the amount of arachidonic acid (AA) detected was significantly lower in plasma (23%), spleen (43%), lungs (41%), and liver (38%), but was unchanged in the heart tissues. The percent of eicosapentaenoic acid (EPA) incorporated into phospholipids of plasma, spleen, lungs, liver, and heart were 7.6, 4.4, 2.1, 7.2, and 1.1%, respectively. These data indicate that after continuous MO feeding, a significant decrease in the production of proinflammatory eicosanoids was associated with a marked reduction in AA content. Further, these data suggest that nutritional intervention may have a therapeutic potential to ameliorate clinical symptoms due to excessive productions of eicosanoids during acute septic complications.

  9. Fabrication and manipulation of polymeric magnetic particles with magnetorheological fluid

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Lopez, Jaime [Centro de Acustica Aplicada y Evaluacion No Destructivos (CAEND), CSIC-UPM, C/Serrano 144, 28006, Madrid (Spain); Shum, Ho Cheung, E-mail: ashum@hku.hk [Department of Mechanical Engineering, University of Hong Kong, 7/F Haking Wong Building, Pokfulam Road (Hong Kong); Elvira, Luis; Montero de Espinosa, Francisco [Centro de Acustica Aplicada y Evaluacion No Destructivos (CAEND), CSIC-UPM, C/Serrano 144, 28006, Madrid (Spain); Weitz, David A., E-mail: weitz@seas.harvard.edu [Department of Physics and School of Engineering and Applied Sciences, Harvard University, 9 and 15 Oxford Street, Cambridge, MA 02138 (United States)

    2013-01-15

    Polymeric magnetic microparticles have been created using a microfluidic device via ultraviolet (UV) polymerization of double emulsions, resulting in cores of magnetorheological (MR) fluids surrounded by polymeric shells. We demonstrate that the resultant particles can be manipulated magnetically to achieve triggered rupture of the capsules. This illustrates the great potential of our capsules for triggered release of active ingredients encapsulated in the polymeric magnetic microparticles. - Highlights: Black-Right-Pointing-Pointer Polymeric microparticles encapsulating MR fluids have been fabricated. Black-Right-Pointing-Pointer A double-emulsion-templated approach using microfluidic techniques has been used. Black-Right-Pointing-Pointer The monodisperse microparticles obtained are easily manipulated under magnetic field. Black-Right-Pointing-Pointer These microparticles have great potential for encapsulation-and-release applications.

  10. Tunable Pickering emulsions with polymer-grafted lignin nanoparticles (PGLNs).

    Science.gov (United States)

    Silmore, Kevin S; Gupta, Chetali; Washburn, Newell R

    2016-03-15

    activities, and polymer-nanoparticle interactions are critical for optimizing interfacial activities. Controlled radical polymerization is a powerful tool for polymer grafting that can leverage the intrinsic interfacial functions of lignin for the formation of Pickering emulsions.

  11. 机械活化淀粉接枝丙烯酰胺/丙烯酸反相乳液聚合动力学*%Kinetics of graft co-polymerization of acrylamide/acrylic onto mechanically-activated starch in inverse emulsion

    Institute of Scientific and Technical Information of China (English)

    谢新玲; 童张法; 李丽琴; 黄祖强; 张友全; 赵秋菊

    2014-01-01

    淀粉接枝共聚物是一种新型功能性材料。以机械活化淀粉(mSt)为接枝母体,丙烯酰胺(AM)和丙烯酸(AA)为接枝单体,研究了在淀粉/单体/乳化剂/油/水反相乳液体系中引发机械活化淀粉与丙烯酰胺/丙烯酸接枝共聚反应的动力学,考察了引发剂浓度[I]、单体浓度[M]、淀粉乳浓度[mSt]和乳化剂浓度[E]等因素对表观聚合速率Rp 的影响。结果表明,在本文考察范围内动力学关系式为 Rp ∝[mSt ]1.5[M]1.7[I]0.9[E]0.92,单体浓度和淀粉乳液浓度对聚合反应速率影响显著,聚合反应速率随体系温度升高而加快,在45~60℃范围内,聚合反应的表观活化能为89.5 kJ/mol,聚合过程中单基终止与双基终止反应同时存在。%The graft copolymer of strach was a new kind of functional material.The kinetics of graft co-poly-merization of in the inverse emulsion system,mechanically-activated starch(mSt)/monomer/emulsifier/oil/wa-ter,were investigated with mechanically-activated starch and acrylamide(AM)/acrylic(AA)as the raw materi-al.The rate orders of graft co-polymerization with respect to the concentrations of initiator,monomer,starch, and emulsifier were determined.The results show that the dependence of the polymerization rate RP on the components concentration in the polymerization system can be expressed for all four components by the follow-ing equation:RP∝[mSt]1.5 [M]1.7 [I]0.9 [E]0.92 .The influences of concentrations of starch and monomer on the rate orders of graft co-polymerization are predominant in four factors.The overall activation energy for the pol-ymerization process was 89.5 kJ/mol,and the unimolecular and bimolecular terminations of free radicals are concomitant presence in the reaction process.

  12. Emulsions for interfacial filtration.

    Energy Technology Data Exchange (ETDEWEB)

    Grillet, Anne Mary; Bourdon, Christopher Jay; Souza, Caroline Ann; Welk, Margaret Ellen; Hartenberger, Joel David; Brooks, Carlton, F.

    2006-11-01

    We have investigated a novel emulsion interfacial filter that is applicable for a wide range of materials, from nano-particles to cells and bacteria. This technology uses the interface between the two immiscible phases as the active surface area for adsorption of targeted materials. We showed that emulsion interfaces can effectively collect and trap materials from aqueous solution. We tested two aqueous systems, a bovine serum albumin (BSA) solution and coal bed methane produced water (CBMPW). Using a pendant drop technique to monitor the interfacial tension, we demonstrated that materials in both samples were adsorbed to the liquid-liquid interface, and did not readily desorb. A prototype system was built to test the emulsion interfacial filter concept. For the BSA system, a protein assay showed a progressive decrease in the residual BSA concentration as the sample was processed. Based on the initial prototype operation, we propose an improved system design.

  13. Surfactantes reativos não-iônicos em polimerização em emulsão de látices de acetato de vinila - vinil neodecanoato: influência nas propriedades de barreira à água Nonionic reactive surfactants in emulsion polymerization of vinyl acetate - vinyl neodecanoate latexes: influence on the water barrier properties

    Directory of Open Access Journals (Sweden)

    Jorge M. de Oliveira

    2009-01-01

    Full Text Available A indústria de tintas é grande consumidora de látex obtido por polimerização em emulsão. Os surfactantes, essenciais à estabilidade do látex, exercem papel fundamental na produção e na aplicação destes polímeros. Contudo, podem também produzir efeitos adversos nas propriedades do produto, em razão de sua adsorção física às partículas de polímero. Os surfactantes não ligados podem migrar através do filme para as interfaces, formando agregados que podem aumentar a sensibilidade à água, afetando desta forma as propriedades de barreira. Um caminho promissor para minimizar este efeito dos surfactantes convencionais tem sido o uso de surfactantes polimerizáveis, ou reativos, que estão covalentemente ligados ao polímero e, desta forma, não podem ser dessorvidos e migrarem durante a formação do filme. Neste trabalho foram preparados látices de acetato de vinila - vinil neodecanoato (VeoVa 10®, estabilizados com surfactantes não-iônicos convencionais e reativos, e avaliado o desempenho dos filmes obtidos a partir destes látices. Os resultados demonstraram que o uso de surfactantes não-iônicos polimerizáveis pode, sob determinadas condições, trazer ganhos para as propriedades de barreira.The paint industry is a huge consumer of latex from emulsion polymerization. The surfactants, essential to the stability of the latex, play a crucial role in the production and application of emulsion polymers. However, they can also have adverse effects on product properties due to their physical adsorption on the polymer particles. The unbound surfactants can migrate through the film toward the interfaces forming aggregates which increase water sensitivity of the film, thus affecting its barrier properties. A promising way to reduce the negative effects of the conventional surfactants is to use polymerizable or reactive surfactants (surfmers that are covalently linked to the polymer, which avoids its desorption and migration

  14. Droplet migration in emulsion systems measured using MR methods.

    Science.gov (United States)

    Hollingsworth, K G; Johns, M L

    2006-04-15

    The migration of emulsion droplets under shear flow remains a largely unexplored area of study, despite the existence of an extensive literature on the analogous problem of solid particle migration. A novel methodology is presented to track the shear-induced migration of emulsion droplets based on magnetic resonance imaging (MRI). The work is in three parts: first, single droplets of one Newtonian fluid are suspended in a second Newtonian fluid (water in silicone oil (PDMS)) and are tracked as they migrate within a Couette cell; second, the migration of emulsion droplets in Poiseuille flow is considered; third, water-in-silicone oil emulsions are sheared in a Couette cell. The effect of (a) rotational speed of the Couette, (b) the continuous phase viscosity, and (c) the droplet phase concentration are considered. The equilibrium extent of migration and rate of migration increase with rotational speed for two different emulsion systems and increased continuous phase viscosity, leads to a greater equilibrium extent of migration. The relationship between the droplet phase concentration and migration is however complex. These results for semi-concentrated emulsion systems and wide-gap Couette cells are not well described by existing models of emulsion droplet migration.

  15. Rheology of Emulsion-Filled Gels Applied to the Development of Food Materials

    Directory of Open Access Journals (Sweden)

    Ivana M. Geremias-Andrade

    2016-08-01

    Full Text Available Emulsion-filled gels are classified as soft solid materials and are complex colloids formed by matrices of polymeric gels into which emulsion droplets are incorporated. Several structural aspects of these gels have been studied in the past few years, including their applications in food, which is the focus of this review. Knowledge of the rheological behavior of emulsion-filled gels is extremely important because it can measure interferences promoted by droplets or particle inclusion on the textural properties of the gelled systems. Dynamic oscillatory tests, more specifically, small amplitude oscillatory shear, creep-recovery tests, and large deformation experiments, are discussed in this review as techniques present in the literature to characterize rheological behavior of emulsion-filled gels. Moreover, the correlation of mechanical properties with sensory aspects of emulsion-filled gels appearing in recent studies is discussed, demonstrating the applicability of these parameters in understanding mastication processes.

  16. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Kawahara, H.; Asada, T. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Naka, T. [Institute of Advanced Research, Nagoya University (Japan); Naganawa, N.; Kuwabara, K.; Nakamura, M. [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

    2014-08-15

    Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R and D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion.

  17. Preparation of hybrid thiol-acrylate emulsion-templated porous polymers by interfacial copolymerization of high internal phase emulsions.

    Science.gov (United States)

    Langford, Caitlin R; Johnson, David W; Cameron, Neil R

    2015-05-01

    Emulsion-templated highly porous polymers (polyHIPEs), containing distinct regions differing in composition, morphology, and/or properties, are prepared by the simultaneous polymerization of two high internal phase emulsions (HIPEs) contained within the same mould. The HIPEs are placed together in the mould and subjected to thiol-acrylate photopolymerization. The resulting polyHIPE material is found to contain two distinct semicircular regions, reflecting the composition of each HIPE. The original interface between the two emulsions becomes a copolymerized band between 100 and 300 μm wide, which is found to be mechanically robust. The separate polyHIPE layers are distinguished from one another by their differing average void diameter, chemical composition, and extent of contraction upon drying.

  18. Ultrasonic Studies of Emulsion Stability in the Presence of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    A. Józefczak

    2015-01-01

    Full Text Available Pickering emulsions are made of solid particle-stabilized droplets suspended in an immiscible continuous liquid phase. A magnetic emulsion can be obtained using magnetic particles. Solid magnetic nanoparticles are adsorbed strongly at the oil-water interface and are able to stabilize emulsions of oil and water. In this work emulsions stabilized by magnetite nanoparticles were obtained using high-energy ultrasound waves and a cavitation mechanism and, next, their stability in time was tested by means of acoustic waves with a low energy, without affecting the structure. An acoustic study showed high stability in time of magnetic emulsions stabilized by magnetite particles. The study also showed a strong influence of an external magnetic field, which can lead to changes of the emulsion properties. It is possible to control Pickering emulsion stability with the help of an external stimulus—a magnetic field.

  19. Synthesis of polyacrylonitrile using AGET-ATRP in emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jing; Chen, Hou, E-mail: lduchenhou@hotmail.com; Liu, Delong; Ji, Naiyi; Zong, Guangxi

    2013-01-01

    The technique of activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP) of acrylonitrile (AN) has been first attempted in emulsion using the procedure of 'one-pot', 'two-step' with polyethylene glycol monooleyl ether (Brij 35) as surfactant, cupric chloride (CuCl{sub 2}) as catalyst, hexamethylenetetramine (HMTA) as ligand, carbon tetrachloride (CCl{sub 4}) as initiator and ascorbic acid (VC) as reducing agent. The polymerization proceeds in controlled/living manner as indicated by first-order kinetics of the polymerization rate with respect to the monomer concentration, linear increase of the molecular weight of polyacrylonitrile (PAN) with monomer conversion and narrow polydispersity. Monomer conversion increases initially with the increase of ligand HMTA and then decreases. The ratio of [AN1] to [AN2] at 1:3 not only gives better control on the molecular weight and the molecular weight distribution, but also provides a more rapid polymerization rate. The rate of polymerization shows a trend of increase along with CCl{sub 4} content. The apparent activation energy of the polymerization is calculated to be 46.6 kJ/mol. Chain extension of PAN with AN was also carried out and the chain extended PAN with 20520 molecular weight and 1.36 polydispersity was successfully obtained. - Graphical abstract: Kinetic plot for AGET ATRP of AN in emulsion AGET-ATRP of AN has first investigated in emulsion with HMTA as ligand, CCl{sub 4} as initiator and VC as reducing agent. The polymerizations have been successfully conducted in a controlled manner in the presence of air as evidenced by a linear first-order kinetic plot and linear increase of molecular weight with monomer conversion. Highlights: Black-Right-Pointing-Pointer AGET-ATRP of AN is first investigated in emulsion. Black-Right-Pointing-Pointer HMTA is used as ligand. Black-Right-Pointing-Pointer Chain extension of PAN with AN verifies the living nature of the

  20. Emulsion Inks for 3D Printing of High Porosity Materials.

    Science.gov (United States)

    Sears, Nicholas A; Dhavalikar, Prachi S; Cosgriff-Hernandez, Elizabeth M

    2016-08-01

    Photocurable emulsion inks for use with solid freeform fabrication (SFF) to generate constructs with hierarchical porosity are presented. A high internal phase emulsion (HIPE) templating technique was utilized to prepare water-in-oil emulsions from a hydrophobic photopolymer, surfactant, and water. These HIPEs displayed strong shear thinning behavior that permitted layer-by-layer deposition into complex shapes and adequately high viscosity at low shear for shape retention after extrusion. Each layer was actively polymerized with an ultraviolet cure-on-dispense (CoD) technique and compositions with sufficient viscosity were able to produce tall, complex scaffolds with an internal lattice structure and microscale porosity. Evaluation of the rheological and cure properties indicated that the viscosity and cure rate both played an important role in print fidelity. These 3D printed polyHIPE constructs benefit from the tunable pore structure of emulsion templated material and the designed architecture of 3D printing. As such, these emulsion inks can be used to create ultra high porosity constructs with complex geometries and internal lattice structures not possible with traditional manufacturing techniques.

  1. Influence of Initiator on Synthesis and Properties of Polyurethane-acrylate Hybrid Emulsion

    Institute of Scientific and Technical Information of China (English)

    HU Guowen; SHEN Huifang; FIU Heqing; CHEN Huanqin

    2008-01-01

    The prepolymer polyurethanes(PUs)based on isophorone diisocyanate(IPDI),poly(propylene glycol)(PPG),1,4-butanedioi(BDO)and dimethylopropionic acid(DMPA)were synthesized at 75-80℃ for 7-8 hours,using dibutyltin dilauate(DBTDL)as catalyzer,and polyturethane-acrylate hybrid emulsion was prepared after methyl methacrylate(MMA)was polymerized,using potassium persulfate and azobisisobutyronitrile(AIBN)as initiator,respectively.The influences of these factors such as the kind of initiator,the feed method of initiator and the addition of initiator on properties of polyurethane-acrylate were studied.The FTIR and GPC of aqueous polyurethane were analyzed.The FTIR spectra show that the degree of microphase-separate between the soft segments and rigid segments is high.The analysis of molecular weights stated that molecular weights increased most significantly after amine was added.The experimental results reveal that the appearance of emulsion is excellent,the film is harder and the water absorption radio of the film is less when oil-solubility AIBN is used as initiator.The semi-continuous can increase the molecular weight of polymer and the optimum amount of the initiator was 3% for MMA.

  2. Cellulose nanofibrils for one-step stabilization of multiple emulsions (W/O/W) based on soybean oil.

    Science.gov (United States)

    Carrillo, Carlos A; Nypelö, Tiina E; Rojas, Orlando J

    2015-05-01

    Cellulose nanofibrils (CNF) were incorporated in water-in-oil (W/O) microemulsions and emulsions, as well as water-in-oil-in-water (W/O/W) multiple emulsions using soybean oil. The addition of CNF to the aqueous phase expanded the composition range to obtain W/O/W emulsions. CNF also increased the viscosity of the continuous phase and reduced the drop size both of which increased the stability and effective viscosity of the emulsions. The effects of oil type and polarity on the properties of the W/O/W emulsions were tested with limonene and octane, which compared to soybean oil produced a smaller emulsion drop size, and thus a higher emulsion viscosity. Overall, CNF are a feasible alternative to conventional polysaccharides as stability enhancers for normal and multiple emulsions that exhibit strong shear thinning behavior.

  3. Pickering emulsions stabilized by paraffin wax and Laponite clay particles.

    Science.gov (United States)

    Li, Caifu; Liu, Qian; Mei, Zhen; Wang, Jun; Xu, Jian; Sun, Dejun

    2009-08-01

    Emulsions containing wax in dispersed droplets stabilized by disc-like Laponite clay particles are prepared. Properties of the emulsions prepared at different temperatures are examined using stability, microscopy and droplet-size analysis. At low temperature, the wax crystals in the oil droplets can protrude through the interface, leading to droplet coalescence. But at higher temperatures, the droplet size decreases with wax concentration. Considering the viscosity of the oil phase and the interfacial tension, we conclude that the wax is liquid-like during the high temperature emulsification process, but during cooling wax crystals appear around the oil/water interface and stabilize the droplets. The oil/water ratio has minimal effect on the emulsions between ratios of 3:7 and 7:3. The Laponite is believed to stabilize the emulsions by increasing the viscosity of the continuous phase and also by adsorbing at the oil/water interface, thus providing a physical barrier to coalescence.

  4. Processing emulsions from desalting of crude oil using centrifuges

    Energy Technology Data Exchange (ETDEWEB)

    Steiger, W.; Westenthanner, F.; Reichl, J. [Flottweg GmbH und Co. KGaA, Vilsbiburg (Germany)

    2006-12-15

    Crude oil directly from the well contains brine. This brine is separated using static settling in tanks. Thereby a layer of emulsion is built up in the interface between oil and the brine, which reduces the available tank volume and makes the separation process difficult. In order to break the emulsion there are several approaches, e.g., use of emulsion breaker, treatment using electrical field, ultra sonic, microwave, etc., This article describes a successful commissioning of a centrifuge, a FLOTTWEG, TRICANTER {sup registered}, in the ural-central region. The FLOTTWEG TRICANTER {sup registered} enables a continuous 3-phase-separation, i. e., separation of the emulsion into oil, water and solids without chemical additives. (orig.)

  5. 核壳型聚氨酯-聚丙烯酸酯复合乳液的合成及流变性能研究%Synthesis of core-shell polyurethane-polyacrylate complex emulsion and its rheological properties

    Institute of Scientific and Technical Information of China (English)

    张敬芳; 李雪峰; 王夏琴

    2012-01-01

    以水性聚氨酯(PU)乳液为种子,甲基丙烯酸甲酯(MMA)、苯乙烯(St)、丙烯酸丁酯(BA)、丙烯酸(AA)等为核层单体,采用半连续种子乳液聚合工艺,合成了具有核壳结构的水性聚氨酯-聚丙烯酸酯(PUA)复合乳液.通过透射电镜(TEM)、差示扫描量热分析(DSC)、傅里叶红外光谱(FTIR)、粒径分析等方法对乳液及其所成乳胶膜的结构和性能进行了测定.另外,还对PUA复合乳液及以其作为粘合剂所制成的数码喷墨印花墨水(乳液墨水)进行了流变性能研究,结果表明:PUA复合乳液在高速率剪切条件下呈现牛顿流体的特性,粘性在乳液体系中占主导地位;乳液墨水也表现出相似的流变学性能,乳液粒子与颜料粒子之间存在一定的相互作用.%Core-shell waterborne polyurethane-polyacrylate complex emulsion was prepared by semi-continuous seed emulsion polymerization using waterborne polyurethane (PU) emulsion as seed, methyl meth-acrylate (MMA), styrene (St), butyl acrylate (BA), and acrylic acid (AA) as core layer monomers. The structure and properties of emulsion and its latex film were characterized by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier transmission infrared (FTIR). The rheological properties of PUA complex emulsion and its utilization as the binder for pigment inks of digital inkjet printing were thoroughly investigated. The results showed that PUA complex emulsion exhibited Newtonian fluid behaviors under high viscosity shearing condition and viscous behaviors dominated in the emulsion system. The emulsion ink occurred similar rheological properties, and there was some interaction between the emulsion and pigment particles.

  6. 有机无机杂化丙烯酸乳液的制备及涂膜性质研究%Preparation of Organic and Inorganic Hybrid Acrylic Emulsion and Properties of Its Films

    Institute of Scientific and Technical Information of China (English)

    刘芳; 黄伟

    2011-01-01

    为了制备一种疏水抗覆冰涂料,采用种子半连续乳液聚合法,通过添加乙烯基三乙氧基硅烷(A-151)和纳米二氧化硅粉末,分别合成了纯丙乳液、硅丙乳液和纳米二氧化硅/硅丙复合乳液,并将乳液涂覆在铝片表面,室温干燥成膜.利用红外光谱、粒度分析、扫描电镜等测试手段对3种乳液及其涂膜性能进行表征.结果表明:添加A-151可以使涂膜交联度提高到95%,吸水率降低到5%;添加纳米二氧化硅,可提高乳液涂膜的热分解温度,使乳液粒径大小分布均匀.此方法中,A-151和纳米二氧化硅改性的乳液涂膜疏水作用有限,仅使接触角增加到约30°.%A hydrophobic anti -icing coating was prepared with pure acrylic emulsion, silicon -acrylate emulsion and nano - silica/silicone - acrylate composite emulsion respectively, which were prepared by the semi - continuous emulsion polymerization process, with addition of vinyl triethoxye silane (A - 151) and nauosilica powder. Films were prepared these emulsion applied on the surface of aluminum sheet separately and dried at room temperature. The structure of these three kind of emulsions and films were charactered by FT-IR, particle size analysis and SEM. The results showed that addition of A - 151 can increase the crosslinking degree of film to 95% , while the water absorbability reduced to 5%. The thermal decomposition temperatures of these films went higher by using nano - silica. Nano - silica was also helpful for the uniform distribution of diameter of emulsions' particles. The contact angle of the films of silicone - acrylate emulsion and nano - silica/silicone - acrylate composite emulsion was increased slightly to 30°.

  7. Rheology of unstable mineral emulsions

    Directory of Open Access Journals (Sweden)

    Sokolović Dunja S.

    2013-01-01

    Full Text Available In this paper, the rheology of mineral oils and their unstable water emulsion were investigated. The oil samples were domestic crude oil UA, its fractions UA1, UA4 and blend semi-product UP1, while the concentration of oil in water emulsions was in the range from 1 up to 30%. The results were analyzed based on shear stress. The oil samples UA, UA1 and UP1 are Newtonian fluids, while UA4 is pseudoplastic fluid. The samples UA and UA4 show higher value of shear stress (83.75 Pa, 297 Pa, then other two samples UA1 and UP1 (18.41 Pa, 17.52 Pa. Rheology of investigated oils due to its complex chemical composition should be analyzed as a simultaneous effect of all their components. Therefore, structural composition of the oils was determined, namely content of paraffins, naphthenes, aromatics and asphaltenes. All samples contain paraffins, naphthenes and aromatics but only oils UA and UA4 contain asphaltenes as well. All investigated emulsions except 30% EUA4 are Newtonian fluids. The EUA4 30% emulsion shows pseudoplastic behaviour, and it is the only 30% emulsion among investigated ones that achieves lower shear stress then its oil. The characteristics of oil samples that could have an influence on their properties and their emulsion rheology, were determined. These characteristics are: neutralization number, interfacial tension, dielectric constant, and emulsivity. Oil samples UA and UA4 have significantly higher values of neutralization number, dielectric constants, and emulsivity. The sample UA has the lowest value of interface tension and the greatest emulsivity, indicating that this oil, among all investigated, has the highest preference for building emulsion. This could be the reason why 20% and 30% emulsions of the oil UA achieve the highest shear stress among all investigated emulsions.

  8. Dual release of proteins from porous polymeric scaffolds

    NARCIS (Netherlands)

    Sohier, J.; Vlugt, T.J.H.; Cabrol, N.; Blitterswijk, van C.; Groot, de K.; Bezemer, J.M.

    2006-01-01

    To create porous scaffolds releasing in a controlled and independent fashion two different proteins, a novel approach based on protein-loaded polymeric coatings was evaluated. In this process, two water-in-oil emulsions are forced successively through a prefabricated scaffold to create coatings, con

  9. Condensation Polymerization

    Indian Academy of Sciences (India)

    S Ramakrishnan

    2017-04-01

    The very idea that large polymer molecules can indeed existwas hotly debated during the early part of the 20th century.As highlighted by Sivaram in his articles on Carothersand Flory, Staudinger’s macromolecular hypothesis was finallyaccepted, and the study of polymers gained momentumbecause of the remarkable efforts of the these two individualswho laid down the foundations concerning the processes thatled to the formation of large polymer molecules, and to thosethat led to an understanding of many of their extraordinaryphysical properties. Condensation polymerizations, as thename suggests, utilizes bond-forming reactions that generatea small molecule condensate, which often needs to be continuouslyremoved to facilitate the formation of the polymer. Inthis article, I shall describe some of the essential principles ofcondensation polymerizations or more appropriately calledstep-growth polymerizations; and I will also describe someinteresting extensions that lead to the formation of polymernetworks and highly branched polymers.

  10. Synthesis and application of a monodispersed acetate-acrylate emulsion%一种单分散醋-丙乳液的合成与应用研究

    Institute of Scientific and Technical Information of China (English)

    王建方; 毛明富; 龚雁; 倪忠斌; 陈明清

    2011-01-01

    A kind of vinyl acetate-acrylate emulsion was synthesized by pre-emulsified and semi-continuous seed emulsion polymeri-zation using vinyl acetate(Vac)and butyl acrylale(BA)as comonomer in the presence of glycidylmethacrylate(CMA)as functional monomer. The size,size distribution and morphologies of the emulsion particles were characterized by transmission electron micros-copy (TEM) and laser light scattering(LLS). It was found that the size of emulsion particles is about 120 nm and presented good mono-dispeisibility. Zeta potential and theological determination results showed that the emulsion particles have plenty negative charges,the surface Zeta potential was-57.2mV. Emulsion presented pseudoplastic fluid property which the storage time was above 9 months under room temperature. It means that the emulsion have good dispersion stability.%以醋酸乙烯酯(VAc)、丙烯酸正丁酯(BA)和甲基丙烯缩水甘油酯(GMA)为共聚单体,采用预乳化-半连续种子乳液聚合的方法,合成了一类改性醋丙乳液.用透射电子显微镜(TEM)、激光光散射(LLS)等测定了乳胶粒的粒径、粒径分布和粒子形态,发现其粒径在120 nm左右,并呈现较好的单分散特性;Zeta电位和流变测定结果显示:该乳胶粒子表面的Zeta电位为-57.2 mV,说明其带有较多的负电荷,乳液呈现出假塑性流体的特征,室温条件下该乳液储存时间可长达9个月以上,具有较好的分散稳定性.

  11. Pickering乳液聚合制备草莓型PSt/SiO_2有机-无机复合微球%Preparation of Raspberry-Like PSt/Si02 Organic-Inorganic Nanocomposite Microspheres Through Pickering Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    张玉红; 董正凤; 王治国; 何培新

    2012-01-01

    Polystyrene /SiO2 composite microspheres were successfully prepared by Pickering emulsion polymerization using a cationic azo initiator (2, 2'-azobis (isobutyramidine) dihydrochloride (AIBA)) in combination with a commercially available glycerol-functionalized ultrafine aqueous silica sol in the absence of any auxiliary comonomer. Transmission electron microscope (TEM) indicates polystyrene/silica particles with raspberry-like morphology. The particle sizes and final silica content range from 190 nm to 300 nm and 28 % to 44 %, respectively. The influences of initial silica content, AIBA content, reaction temperature on the average diameters and silica contents of the composite microspheres were studied. The result indicates that with the initial silica content increase, the diameter of the composite microspheres tends to decrease and the silica contents adsorbed on the latexes surface increase. The silica content increases with the increase of the AIBA amount. With the reaction temperature increase, the average diameter increases, but the variance of silica content is less.%在纳米硅溶胶分散介质中,以苯乙烯(St)为单体,偶氮二异丁脒盐酸盐(AIBA)为引发剂,不添加任何辅助单体,通过Pickering乳液聚合,成功制备了PSt/SiO2有机-无机复合微球,透射电镜研究显示,复合微球具有草莓型形态。所得复合微球粒径在190 nm-300 nm之间,二氧化硅吸附量介于28%-44%之间。研究了初始硅溶胶用量、AIBA用量和反应温度等因素对复合微球粒子粒径和二氧化硅吸附量的影响。结果发现,初始硅溶胶用量增大,复合微球粒径减小、二氧化硅吸附量增大;引发剂用量增加,二氧化硅吸附量增大;反应温度升高,复合微球粒径增大,但对二氧化硅吸附量影响较小。

  12. Recognizing Amino Acid Chirality with Surface-Imprinted Polymers Prepared in W/O Emulsions

    Directory of Open Access Journals (Sweden)

    Min Jae Shin

    2013-01-01

    Full Text Available A molecularly imprinted polymer was prepared by a surface molecular imprinting technique in water-in-oil (W/O emulsion. In this technique, the solid polymer, which is molecularly imprinted at the internal cavity surface, is prepared by polymerizing W/O emulsions consisting of a water-soluble imprinted molecule, a functional host molecule, an emulsion stabilizer, and a crosslinking agent. Dioleoyl phosphate was used as an emulsion stabilizer, and this compound also acted as a monomer and a host functional group in the imprinted cavity. Divinylbenzene was used as a crosslinker. Tryptophan methyl ester and phenylalanine methyl ester were used as the target template materials. These imprinted polymers exhibited enantiomeric selectivity in absorption experiments, and the maximum separation factor was 1.58. The enantiomeric selectivity with tryptophan methyl ester was higher than that with phenylalanine methyl ester.

  13. Synthesis of polyacrylonitrile using AGET-ATRP in emulsion.

    Science.gov (United States)

    Ma, Jing; Chen, Hou; Liu, Delong; Ji, Naiyi; Zong, Guangxi

    2013-01-01

    The technique of activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP) of acrylonitrile (AN) has been first attempted in emulsion using the procedure of "one-pot", "two-step" with polyethylene glycol monooleyl ether (Brij 35) as surfactant, cupric chloride (CuCl2) as catalyst, hexamethylenetetramine (HMTA) as ligand, carbon tetrachloride (CCl4) as initiator and ascorbic acid (VC) as reducing agent. The polymerization proceeds in controlled/living manner as indicated by first-order kinetics of the polymerization rate with respect to the monomer concentration, linear increase of the molecular weight of polyacrylonitrile (PAN) with monomer conversion and narrow polydispersity. Monomer conversion increases initially with the increase of ligand HMTA and then decreases. The ratio of [AN1] to [AN2] at 1:3 not only gives better control on the molecular weight and the molecular weight distribution, but also provides a more rapid polymerization rate. The rate of polymerization shows a trend of increase along with CCl4 content. The apparent activation energy of the polymerization is calculated to be 46.6 kJ/mol. Chain extension of PAN with AN was also carried out and the chain extended PAN with 20520 molecular weight and 1.36 polydispersity was successfully obtained.

  14. NON-ISOTHERMAL REACTION KINETICS ANALYISIS OF POLYACRYLATE EMULSION CHEMICAL STABILITY

    Institute of Scientific and Technical Information of China (English)

    陈孝康; 孙鹤才

    1995-01-01

    We solved the problem of obtaining conclusions to the procss involved a continuously concentration changing in the emulsion by determination volume rate Vt/V. which give a direct insight easily. The explanation of the mathematical was given. The shelf-life of emulsion was obtained.

  15. Rheological properties of highly concentrated protein-stabilized emulsions.

    Science.gov (United States)

    Dimitrova, Tatiana D; Leal-Calderon, Fernando

    2004-05-20

    We prepared concentrated quasi monodisperse hexadecane-in-water emulsions stabilized by various proteins and investigated their rheological properties. Some protein-stabilized emulsions possess remarkably high elasticity and at the same time they are considerably fragile--they exhibit coalescence at yield strain and practically do not flow. The elastic storage modulus G' and the loss modulus G" of the emulsions were determined for different oil volume fractions above the random close packing. Surprisingly, the dimensionless elastic moduli G'/(sigma/a), sigma being the interfacial tension, and a being the mean drop radius, obtained for emulsions stabilized by different proteins do not collapse on a single master curve. They are almost always substantially higher than the corresponding values obtained for equivalent Sodium Dodecyl Sulfate (SDS)-stabilized emulsions. The unusually high elasticity cannot be attributed to a specificity of the continuous phase, because the osmotic equation of state of our emulsions is found identical to the one obtained for samples stabilized by classical surfactants. In parallel, we mimicked the thin films that separate the droplets in the concentrated emulsion and found that the protein adsorption layers contain a substantial number of sticky surface aggregates. These severely obstruct local rearrangements of individual drops in respect to their neighbors which leads to coalescence at yield strain. Furthermore, we found that G'/(sigma/a) is correlated (for a given oil volume fraction) to the dilatational elastic modulus, of the protein layer adsorbed on the droplets. The intrinsic elasticity of the protein layers, together with the blocked local rearrangements are considered as the main factors determining the unusual bulk elasticity of the studied emulsions.

  16. Enhanced reductive dechlorination in columns treated with edible oil emulsion

    Science.gov (United States)

    Long, Cameron M.; Borden, Robert C.

    2006-09-01

    The effect of edible oil emulsion treatment on enhanced reductive dechlorination was evaluated in a 14 month laboratory column study. Experimental treatments included: (1) emulsified soybean oil and dilute HCl to inhibit biological activity; (2) emulsified oil only; (3) emulsified oil and anaerobic digester sludge; and (4) continuously feeding soluble substrate. A single application of emulsified oil was effective in generating strongly reducing, anaerobic conditions for over 14 months. PCE was rapidly reduced to cis-DCE in all three live columns. Bioaugmentation with a halorespiring enrichment culture resulted in complete dechlorination of PCE to ethene in the soluble substrate column (yeast extract and lactate). However, an additional treatment with a pulse of yeast extract and bioaugmentation culture was required to stimulate complete dechlorination in the emulsion treated columns. Once the dechlorinating population was established, the emulsion only column degraded PCE from 90-120 μM to below detection with concurrent ethene production in a 33 day contact time. The lower biodegradation rates in the emulsion treated columns compared to the soluble substrate column suggest that emulsified oil barriers may require a somewhat longer contact time for effective treatment. In the HCl inhibited column, partitioning of PCE to the retained oil substantially delayed PCE breakthrough. However, reduction of PCE to more soluble degradation products ( cis-DCE, VC and ethene) greatly reduced the impact of oil-water partitioning in live columns. There was only a small decline in the hydraulic conductivity ( K) of column #1 (low pH + emulsion, Kfinal/ Kinitial = 0.57) and column #2 (live + emulsion, Kfinal/ Kinitial = 0.73) indicating emulsion injection did not result in appreciable clogging of the clayey sand. However, K loss was greater in column #3 (sludge +emulsion, Kfinal/ Kinitial = 0.12) and column #4 (soluble substrate, Kfinal/ Kinitial = 0.03) indicating clogging due

  17. Generation of colloidal granules and capsules from double emulsion drops

    Science.gov (United States)

    Hess, Kathryn S.

    Assemblies of colloidal particles are extensively used in ceramic processing, pharmaceuticals, inks and coatings. In this project, the aim was to develop a new technique to fabricate monodispersed colloidal assemblies. The use of microfluidic devices and emulsion processing allows for the fabrication of complex materials that can be used in a variety of applications. A microfluidic device is used to create monodispersed water/oil/water (w/o/w) double emulsions with interior droplets of colloidal silica suspension ranging in size from tens to hundreds of microns. By tailoring the osmotic pressure using glycerol as a solute in the continuous and inner phases of the emulsion, we can control the final volume size of the monodispersed silica colloidal crystals that form in the inner droplets of the double emulsion. Modifying the ionic strength in the colloidal dispersion can be used to affect the particle-particle interactions and crystal formation of the final colloidal particle. This w/o/w technique has been used with other systems of metal oxide colloids and cellulose nanocrystals. Encapsulation of the colloidal suspension in a polymer shell for the generation of ceramic-polymer core-shell particles has also been developed. These core-shell particles have spawned new research in the field of locally resonant acoustic metamaterials. Systems and chemistries for creating cellulose hydrogels within the double emulsions have also been researched. Water in oil single emulsions and double emulsions have been used to create cellulose hydrogel spheres in the sub-100 micron diameter range. Oil/water/oil double emulsions allow us to create stable cellulose capsules. The addition of a second hydrogel polymer, such as acrylate or alginate, further strengthens the cellulose gel network and can also be processed into capsules and particles using the microfluidic device. This work could have promising applications in acoustic metamaterials, personal care products, pharmaceuticals

  18. Programmed emulsions for sodium reduction in emulsion based foods.

    Science.gov (United States)

    Chiu, Natalie; Hewson, Louise; Fisk, Ian; Wolf, Bettina

    2015-05-01

    In this research a microstructure approach to reduce sodium levels in emulsion based foods is presented. If successful, this strategy will enable reduction of sodium without affecting consumer satisfaction with regard to salty taste. The microstructure approach comprised of entrapment of sodium in the internal aqueous phase of water-in-oil-in-water emulsions. These were designed to destabilise during oral processing when in contact with the salivary enzyme amylase in combination with the mechanical manipulation of the emulsion between the tongue and palate. Oral destabilisation was achieved through breakdown of the emulsion that was stabilised with a commercially modified octenyl succinic anhydride (OSA)-starch. Microstructure breakdown and salt release was evaluated utilising in vitro, in vivo and sensory methods. For control emulsions, stabilised with orally inert proteins, no loss of structure and no release of sodium from the internal aqueous phase was found. The OSA-starch microstructure breakdown took the initial form of oil droplet coalescence. It is hypothesised that during this coalescence process sodium from the internalised aqueous phase is partially released and is therefore available for perception. Indeed, programmed emulsions showed an enhancement in saltiness perception; a 23.7% reduction in sodium could be achieved without compromise in salty taste (p sodium reduction in liquid and semi-liquid emulsion based foods.

  19. Food-grade Pickering emulsions stabilised with solid lipid particles.

    Science.gov (United States)

    Pawlik, Aleksandra; Kurukji, Daniel; Norton, Ian; Spyropoulos, Fotis

    2016-06-15

    Aqueous dispersions of tripalmitin particles (with a minimum size of 130 nm) were produced, via a hot sonication method, with and without the addition of food-grade emulsifiers. Depending on their relative size and chemistry, the emulsifiers altered the properties of the fat particles (e.g. crystal form, dispersion state and surface properties) by two proposed mechanisms. Firstly, emulsifiers modify the rate and/or extent of polymorphic transitions, resulting in the formation of fat crystals with a range of polarities. Secondly, the adsorption of emulsifiers at the particle interface modifies crystal surface properties. Such emulsifier-modified fat particles were then used to stabilise emulsions. As the behaviour of these particles was predisposed by the kind of emulsifier employed for their manufacture, the resulting particles showed different preferences to which of the emulsion phases (oil or water) became the continuous one. The polarity of the fat particles decreased as follows: Whey Protein Isolate > Soy Lecithin > Soy Lecithin + Tween 20 > Tween 20 > Polyglycerol Polyricinoleate > no emulsifier. Consequently, particles stabilised with WPI formed oil-in-water emulsions (O/W); particles stabilised solely with lecithin produced a highly unstable W/O emulsion; and particles stabilised with a mixture of lecithin and Tween 20 gave a stable W/O emulsion with drop size up to 30 μm. Coalescence stable, oil-continuous emulsions (W/O) with drop sizes between 5 and 15 μm were produced when the tripalmitin particles were stabilised with solely with Tween 20, solely with polyglycerol polyricinoleate, or with no emulsifier at all. It is proposed that the stability of the latter three emulsions was additionally enhanced by sintering of fat particles at the oil-water interface, providing a mechanical barrier against coalescence.

  20. Thermodynamically Stable Pickering Emulsions Stabilized by Janus Dumbbells

    Science.gov (United States)

    Tu, Fuquan; Park, Bum Jun; Lee, Daeyeon

    2013-03-01

    Janus particles have two sides with different, often opposite, surface properties. Janus dumbbell is one type of Janus particles that consists of two partially fused spherical lobes. It is possible to independently control the geometry and surface wettability of Janus dumbbells. Janus dumbbells can also be produced in a large quantity, making them useful for practical applications such as emulsion stabilization. In this work, we calculate the free energy of emulsion formation using amphiphilic Janus dumbbells as solid surfactants. In contrast to kinetically stable emulsions stabilized by homogeneous particles, emulsion stabilized by Janus dumbbells can be thermodynamically stable. There also exists an optimal radius of droplets that can be stabilized by infinite or limited number of amphiphilic dumbbells in the continuous phase. We demonstrate that the optimal radius of dumbbell-stabilized droplets can be predicted based on the volume of the dispersed phase and the volume fraction of dumbbells in the continuous phase. We believe our calculation will provide guidelines for using Janus dumbbells as colloid surfactants to generate stable emulsions.

  1. NUCLEATION PROCESS AND NUCLEATION MECHANISM OF MMA/BA SEEDED SEMI-CONTINUOUS EMULSION POLYMERIZATION%MMA/BA种子半连续乳液聚合成核过程及机理研究

    Institute of Scientific and Technical Information of China (English)

    张心亚; 孙志娟; 江庆梅; 陈焕钦

    2009-01-01

    引入一种不溶于水的染色剂(BL-S)作示踪剂,研究甲基丙烯酸甲酯(MMA)/丙烯酸丁酯(BA)种子半连续乳液聚合中各变量对成核过程及成核机理的影响,运用最终乳胶粒中染色剂的含量(Pdye)、最终乳胶粒子数(Ncp)、胶束成核和均相成核所形成的粒子数目(Nm和Nh)等参数对聚合过程中的成核情况进行定量分析.结果发现,当引发剂浓度[I]增大时,Pdye、Nh、Nm和Nh/Ncp均随之增大,同时Nm/Ncp相应地减小,且Nm/Ncp=-0.0262[I]+0.8833,表明均相成核随[I]的增大而增加,但胶束成核的比例减小.乳化剂浓度[E]在不同范围内对成核机理的影响不同,在[E]=0.7216×10-2 mol·L-1时,体系中胶束成核和均相成核比例相等,各为50%;当[E]>0.7216×10-2 mol·L-1时,随[E]增大,成核时间t1,2逐渐缩短,Nm/Ncp增加,Nh/Ncp减小,胶束成核所占比例大于均相成核,胶束成核逐渐上升为主要成核方式;反之当[E]<0.7216×10-2 mol·L-1时,体系中胶束成核所占比例小于均相成核,均相成核为主要成核方式.当MMA的摩尔分率fMMA由0增至0.6时,Nm/Ncp从80.93%下降至50%,体系中以胶束成核为主,均相成核为辅;当fMMA由0.6增至1时,Nm/Ncp已降至40%,而Nh/Ncp增至60%,体系中已转变成均相成核为主,胶束成核为辅.在常规和种子半连续乳液聚合中,t1,2分别为12 min和6 min,而Pdye变化较小,表明聚合方式只影响粒子的形成过程和成核时间的长短,对成核方式影响甚微.

  2. Simulation and Control of Nylon-6 Continuous Polymerization Process%尼龙6连续聚合过程的流程模拟与调控

    Institute of Scientific and Technical Information of China (English)

    赵玲; 邢玉林; 秦春曦; 奚桢浩

    2014-01-01

    基于流程模拟软件Aspen Polymer Plus建立了己内酰胺水解聚合生产尼龙6的两段式工艺过程模型,利用该模型对某厂2万吨/年两段式生产工艺进行模拟,各聚合阶段内己内酰胺、环状二聚体含量、聚合物分子量,以及各聚合阶段温度分布和两聚合塔塔顶出水量等结果均与工业值吻合良好,模型可靠。在此基础上,进一步模拟考察了聚合反应过程中进料水含量、分子量调节剂含量、各聚合阶段温度和各聚合塔压力等因素对己内酰胺转化率、环状二聚体生成以及聚合产品分子量的影响,并进行了参数灵敏性分析。结果表明:较低的进料水含量、降低反应温度和前聚塔压力及提高后聚塔的真空度均有利于降低聚合产品中环状二聚体的含量;两个聚合塔下半段的温度变化对环状二聚体产生有显著影响,提高后聚塔真空度可显著提高聚合物分子量。以尼龙6连续聚合过程的环状二聚体含量调控为目标,在优化的操作条件下,尼龙6聚合物中环状二聚体的含量可降低约16%。%Abstrct:A model of two-steps Nylon-6 polymerization process was set up by Aspen Polymer Plus. As the simulational results fit all of the industrial operational data of 20 kt/a manufacture process well, including the composition of caprolactam and cyclic dimer, polymer molecular weight, temperature distribution, and the water yield from the top of two VK tubes, which indicated that the model was reliable. A sensitivity was analyzed by the model to evaluate the adjust ability of operational parameters, including the water and acetic acid contents in feed, temperature distribution and pressure of each VK tube in polymerization process. The results showed that low water content in feed, low reaction temperature, low pressure of the first tube and high vacuum of the secend tube contributed to less cyclic dimer fraction in polymer product. The

  3. Synthesis of Covalently Cross-Linked Colloidosomes from Peroxidized Pickering Emulsions

    Directory of Open Access Journals (Sweden)

    Nadiya Popadyuk

    2016-10-01

    Full Text Available A new approach to the formation of cross-linked colloidosomes was developed on the basis of Pickering emulsions that were stabilized exclusively by peroxidized colloidal particles. Free radical polymerization and a soft template technique were used to convert droplets of a Pickering emulsion into colloidosomes. The peroxidized latex particles were synthesized in the emulsion polymerization process using amphiphilic polyperoxide copolymers poly(2-tert-butylperoxy-2-methyl-5-hexen-3-ine-co-maleic acid (PM-1-MAc or poly[N-(tert-butylperoxymethylacrylamide]-co-maleic acid (PM-2-MAc, which were applied as both initiators and surfactants (inisurfs. The polymerization in the presence of the inisurfs results in latexes with a controllable amount of peroxide and carboxyl groups at the particle surface. Peroxidized polystyrene latex particles with a covalently grafted layer of inisurf PM-1-MAc or PM-2-MAc were used as Pickering stabilizers to form Pickering emulsions. A mixture of styrene and/or butyl acrylate with divinylbenzene and hexadecane was applied as a template for the synthesis of colloidosomes. Peroxidized latex particles located at the interface are involved in the radical reactions of colloidosomes formation. As a result, covalently cross-linked colloidosomes were obtained. It was demonstrated that the structure of the synthesized (using peroxidized latex particles colloidosomes depends on the amount of functional groups and pH during the synthesis. Therefore, the size and morphology of colloidosomes can be controlled by latex particle surface properties.

  4. To Model Chemical Reactivity in Heterogeneous Emulsions, Think Homogeneous Microemulsions.

    Science.gov (United States)

    Bravo-Díaz, Carlos; Romsted, Laurence Stuart; Liu, Changyao; Losada-Barreiro, Sonia; Pastoriza-Gallego, Maria José; Gao, Xiang; Gu, Qing; Krishnan, Gunaseelan; Sánchez-Paz, Verónica; Zhang, Yongliang; Dar, Aijaz Ahmad

    2015-08-25

    Two important and unsolved problems in the food industry and also fundamental questions in colloid chemistry are how to measure molecular distributions, especially antioxidants (AOs), and how to model chemical reactivity, including AO efficiency in opaque emulsions. The key to understanding reactivity in organized surfactant media is that reaction mechanisms are consistent with a discrete structures-separate continuous regions duality. Aggregate structures in emulsions are determined by highly cooperative but weak organizing forces that allow reactants to diffuse at rates approaching their diffusion-controlled limit. Reactant distributions for slow thermal bimolecular reactions are in dynamic equilibrium, and their distributions are proportional to their relative solubilities in the oil, interfacial, and aqueous regions. Our chemical kinetic method is grounded in thermodynamics and combines a pseudophase model with methods for monitoring the reactions of AOs with a hydrophobic arenediazonium ion probe in opaque emulsions. We introduce (a) the logic and basic assumptions of the pseudophase model used to define the distributions of AOs among the oil, interfacial, and aqueous regions in microemulsions and emulsions and (b) the dye derivatization and linear sweep voltammetry methods for monitoring the rates of reaction in opaque emulsions. Our results show that this approach provides a unique, versatile, and robust method for obtaining quantitative estimates of AO partition coefficients or partition constants and distributions and interfacial rate constants in emulsions. The examples provided illustrate the effects of various emulsion properties on AO distributions such as oil hydrophobicity, emulsifier structure and HLB, temperature, droplet size, surfactant charge, and acidity on reactant distributions. Finally, we show that the chemical kinetic method provides a natural explanation for the cut-off effect, a maximum followed by a sharp reduction in AO efficiency with

  5. Emulsion stability: determination from turbidity

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, S.R.; Fogler, H.S.

    1981-01-01

    The relationship between particle size and concentration and turbidity has been developed for a polydispersed system. The stability of acoustically prepared emulsions of C36H74 in water were determined from turbidimetry and found to be in agreement with the stability determined by the freezing method. The turbidimetry method can be used for determining the stability of various emulsions easily and inexpensively. 11 references.

  6. Put the breaks on wastewater emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Alther, G. [Biomin, Inc., Ferndale, MI (United States)

    1998-03-01

    Emulsions in wastewater pose a vexing problem for facilities attempting to recycle water and stay in compliance with permissible discharge limits. But the challenges are no less formidable for routine maintenance. The removal of emulsions, a major constituent of which are fats, oils and greases (FOGs), is necessary to prevent them from depositing on pipes and fouling filtration media. Some of the havoc caused by emulsions can be avoided if emulsions are broken and removed from wastewater streams. Successful emulsion breaking requires a basic understanding of emulsions, their chemical composition, and the technologies required to remove them from water. The paper discusses emulsion basics and emulsion breaking, including counteracting emulsions, testing procedures, physical separation methods, removal strategies, bentonite-based powders, and post-polishing.

  7. Shear Driven Synthesis of Polymeric Micro- and Nanomaterials

    Science.gov (United States)

    Tian, Tian

    usually categorizes emulsion as oil in water (O/W) and water in oil (W/O) dispersions. Oil in oil emulsion can also be formulated from the immiscible organic liquid pairs. Using the phase separation in the PS-cyclohexane system, the emulsion are formed under continuous shearing while the continuous phase is solvent-rich and the disperse phase is polymer-rich. By shearing the emulsions, the fibers sizes are reduced around 10X due to the smaller initial polymer droplet size. The fiber sizes are further reduced to 100 nm which enhances the competitive advantages of liquid shear technique. Controlled drug release combines the advantages of increased therapeutic efficacy, reduced toxicity and lower administration frequency. By dispersing model drugs in the spinning polymer solution, these drugs are successfully encapsulated inside the biodegradable matrix and the encapsulation efficiency is modulated by polymer concentration and fiber size while the release profile of the drug is determined by the degradation rate of the polymer matrix.

  8. 不同环保型操作的性质及对乳聚丁苯橡胶性能的影响%Properties of different environmental-friendly processing oils and their influences on properties of emulsion polymerized styrene-butadiene rubber

    Institute of Scientific and Technical Information of China (English)

    胡海华; 刘春芳; 赵洪国; 吴宇; 何连成; 李波

    2013-01-01

    分析了牌号为NAP-10和AP 15以及处理的馏出芳烃抽出物(TDAE)的性质,考察了以其作操作油对乳聚丁苯橡胶(ESBR)门尼黏度、硫化特性、力学性能、耐老化性能、耐磨性能以及制品外观的影响,并与芳烃油作操作油进行了对比.结果表明,NAP-10、TDAE和AP 15中的多环芳烃质量分数均小于3.00%,属于环保型操作油.3种环保型操作油对ESBR的软化能力和加工安全性均高于芳烃油.采用3种环保型操作油制备的ESBR硫化胶的力学性能、耐老化性能和耐磨性能略逊于以芳烃油为操作油的硫化胶,且放置一段时间后橡胶制品均有油品析出现象,随着操作油中芳烃含量的增加,油品析出减少,其中用AP 15作操作油制备的硫化胶的耐磨性能和制品外观最好.%The properties of brand NAP-10, AP 15 and triple distillate aromatic extracts (TDAE) were analyzed, their influences as processing oils on properties, such as Mooney viscosity, curing characteristics, mechanical properties, aging resistance and abrasion resistance as well as appearance of manufactures of emulsion polymerized styrene-butadiene rubber ( ESBR ) were investigated and compared with those of aromatic oil as processing oil. The results showed that the mass fraction of polycy-clic aromatic hydrocarbons in NAP-10, AP 15 and TDAE were less than 3. 00% , so they were all environmental-friendly processing oils. The softening ability and processing safety when using these three as processing oil of ESBR were higher than those of aromatic oil as processing oil. The mechanical properties, aging resistance and abrasion resistance of ESBR vulcanizates with the three kinds of environmental-friendly processing oils were inferior to those of ESBR vulcanizates with aromatic oil, and there were oil stains on surface of ESBR manufactures after stored for a period, the phenomenon decreased with increasing aromatics content in the processing oils. The abrasion resistance

  9. Preparation of Polyacrylamide with High Relative Molecular Mass and High Cationic Degree Through Inverse Emulsion Polymerization%反相乳液聚合制备高相对分子质量和高阳离子度的聚丙烯酰胺

    Institute of Scientific and Technical Information of China (English)

    段文猛; 邓清月; 李爽; 马中亮

    2011-01-01

    以丙烯酰胺(AM)和丙烯酰氧乙基三甲基氯化铵(DAC)为单体,采用反相乳液聚合制备了高相对分子质量和高阳离子度的聚丙烯酰胺( P( AM - DAC));考察了乳化剂和引发剂的种类,乳化剂、引发剂、AM和阳离子单体DAC用量,乳化剂亲水亲油平衡值(HLB)对P( AM - DAC)的特性黏数的影响.实验结果表明,含脂肪醇聚氧乙烯醚(MOA) - 3/MOA -9复合乳化剂的乳液体系稳定性最好,偶氮二异丁基脒盐酸盐(V -50)的引发效果最好.采用正交实验确定了最佳合成条件:MOA-3/MOA-9复合乳化剂质量分数(基于反应体系的总质量)和HLB值分别为4.8%和8.6、AM和DAC的总质量分数为40%(基于反应体系的总质量)、V -50质量分数为0.09%(基于单体的总质量)、DAC摩尔分数55%(基于单体总的物质的量).在最佳合成条件下合成的P(AM-DAC)的特性黏数最大(1 378.7 mL/g),对含聚污水的絮凝效果好.%Polyacrylamide ( P ( AM-DAC)) with high relative molecular mass and high cationic degree was prepared from acrylamide (AM) and acryloyloxyethyltrimethyl ammonium chloride(DAC) as a cationic monomer through inverse emulsion polymerization. The effects of the types of emulsifiers and initiators, the dosages of emulsifiers, initiators and monomers, and the emulsifier hydrophilic-lipophilic balance ( HLB) on the intrinsic viscosity of P ( AM-DAC) were studied by orthogonal experiments. The results showed that under the optimum conditions of 4. 8% (w) (based on the total mass of the reaction system) fatty alcohol-polyoxyethylene ether MOA-3/MOA-9 with HLB of 8.6 as the composite emulsifier, 0. 09% ( w) (based on the total monomer mass) 2, 2'-azobis ( 2-methylpropionam-ide) dihydrochloride( V-50) as the initiator, 40% (w) total monomers (based on the total mass of the reaction system) and 55% (x) DAC (based on the total amount of substance of monomer), the intrinsic viscosity of the produced P( AM-DAC) reached the maximum (1 378.7 m

  10. The Modification of the Acrylate Emulsion for Water-Based Coatings

    Institute of Scientific and Technical Information of China (English)

    Chen Wei-Feng; Fa-Ai Zhang

    2005-01-01

    @@ 1Introduction The developments of the environment friendly materials and technology are largely promoted recently.There also come some new kinds of coatings including water-based coating, powder coating, high-solid coating and UV-cured coating[1]. The emulsion polymerization is the main method for preparing the polymer for coatings. One of the most widely used polymers is acrylate resin which is not well in some properties, such as weather resistance, endurance and water resistance[2]. We hope to improve the various properties of the acrylic emulsion by adding silicone made from tetraethyl orthosilicate(TEOS), making it better applied in coating field.

  11. Biokompatible Polymere

    Science.gov (United States)

    Ha, Suk-Woo; Wintermantel, Erich; Maier, Gerhard

    Der klinische Einsatz von synthetischen Polymeren begann in den 60-er Jahren in Form von Einwegartikeln, wie beispielsweise Spritzen und Kathetern, vor allem aufgrund der Tatsache, dass Infektionen infolge nicht ausreichender Sterilität der wiederverwendbaren Artikel aus Glas und metallischen Werkstoffen durch den Einsatz von sterilen Einwegartikeln signifikant reduziert werden konnten [1]. Die Einführung der medizinischen Einwegartikel aus Polymeren erfolgte somit nicht nur aus ökonomischen, sondern auch aus hygienischen Gründen. Wegen der steigenden Anzahl synthetischer Polymere und dem zunehmenden Bedarf an ärztlicher Versorgung reicht die Anwendung von Polymeren in der Medizin von preisgünstigen Einwegartikeln, die nur kurzzeitig intrakorporal eingesetzt werden, bis hin zu Implantaten, welche über eine längere Zeit grossen Beanspruchungen im menschlichen Körper ausgesetzt sind. Die steigende Verbreitung von klinisch eingesetzten Polymeren ist auf ihre einfache und preisgünstige Verarbeitbarkeit in eine Vielzahl von Formen und Geometrien sowie auf ihr breites Eigenschaftsspektrum zurückzuführen. Polymere werden daher in fast allen medizinischen Bereichen eingesetzt.

  12. Radiological decontamination strippable coatings using PVA and PVP based core-shell polymeric scintillation materials

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ho Sang; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    Strippable coatings are innovative technologies for decontamination that effectively reduce loose contamination. These coatings are polymer mixtures, such as water-based organic polymers that are applied to a surface by paintbrush, roller or spray applicator. In this study, the core-shell composite polymer for decontamination from the surface contamination was synthesized by the method of emulsion polymerization and blends of polymers. The strippable polymer emulsion is composed of the poly(styrene-ethyl acrylate) [poly(St-EA)] composite polymer, poly(vinyl alcohol) (PVA) and polyvinylpyrrolidone (PVP). The morphology of the composite emulsion particle was core-shell structure, with polystyrene (PS) as the core and poly(ethyl acrylate) (PEA) as the shell. Core-shell polymers of styrene (St)/ethyl acrylate (EA) pair were prepared by sequential emulsion polymerization in the presence of sodium dodecyl sulfate (SDS) as an emulsifier using ammonium persulfate (APS) as an initiator. Related tests and analysis confirmed the success in synthesis of composite polymer. The products are characterized by FT-IR spectroscopy, TGA that were used, respectively, to show the structure, the thermal stability of the prepared polymer. Two-phase particles with a core-shell structure were obtained in experiments where the estimated glass transition temperature and the morphologies of emulsion particles. Decontamination factors (DF) of the strippable polymeric emulsion were evaluated with the polymer blend contents

  13. The Research on Modeling and Simulation of TFE Polymerization Process

    Directory of Open Access Journals (Sweden)

    Jing Gao Sun

    2014-01-01

    Full Text Available PTFE (polytetrafluoroethylene is the fluorinated straight-chain polymer, made by the polymerization of tetrafluoroethylene monomer; it is used widely because of its excellent performance and can be obtained by the polymerization of body, solutions, suspensions, and emulsions. But only the last two are the main ways. This research paper makes simulation based on Polymer Plus. It uses the emulsion polymerization method at background to carry out a semibatch reactor system. Upon the actual production conditions, simulation process under the steady state conditions is used to analyze the effects of the changes on operating conditions; the corresponding dynamic model is created to analyze the impact of the changes of conditions on the entire system. Moreover, the amount of APS which plays an important part in this reaction is discussed for getting the most suitable amount of initiator. Because of less research work on this job, it is so difficult to find the related data from the literature. Therefore, this research will have a great significance for the process of the tetrafluoroethylene emulsion polymerization in the future.

  14. Structural and thermal properties of the Poly(styrene-ethyl acrylate) polymeric scintillation material for surface radioactive contamination measurement

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ho Sang; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    Emulsion polymerization is a unique chemical process widely used to produce waterborne resins with various colloidal and physicochemical properties. These emulsion polymers find a wide range of applications such as synthetic rubbers, thermoplastics, coatings, adhesives, binders, rheological modifiers, plastics pigments, standards for the calibration of instruments, polymeric supports for the purification of proteins and drug delivery system, etc. Polystyrenes are widely employed as matrices in order to dope scintillating dyes for alpha and beta radiation sensors. For example, BC-400 (Bicron Direct Saint-Gobain, MA), a polyvinyltoluene-based scintillator doped with PPO and POPOP, is the best existing plastic scintillator for alpha particle detection. Using emulsion polymerization technique described in a previous communication, experiments have been performed to investigate the detection performance with the scintillators contents. In this paper, the properties of the polymer for radioactive contaminant measurement observed under various condition of polymerization and variously EA contents.

  15. Comparison of Pickering and network stabilization in water-in-oil emulsions.

    Science.gov (United States)

    Ghosh, Supratim; Tran, Tu; Rousseau, Dérick

    2011-06-07

    We compared the efficacy of Pickering crystals, a continuous phase crystal network, and a combination thereof against sedimentation and dispersed phase coalescence in water-in-oil (W/O) emulsions. Using 20 wt % water-in-canola oil emulsions as our model, glycerol monostearate (GMS) permitted Pickering-type stabilization, whereas simultaneous usage of hydrogenated canola oil (HCO) and glycerol monooleate (GMO) primarily led to network-stabilized emulsions. A minimum of 4 wt % GMS or 10 wt % HCO was required for long-term sedimentation stability. Although there were no significant differences between the two in mean droplet size with time, the free water content of the network-stabilized emulsions was higher than Pickering-stabilized emulsions, suggesting higher instability. Microscopy revealed the presence of crystal shells around the dispersed phase in the GMS-stabilized emulsions, whereas in the HCO-stabilized emulsion, spherulitic growth in the continuous phase and on the droplet surface occurred. The displacement energy (E(disp)) to detach crystals from the oil-water interface was ∼10(4) kT, and was highest for GMS crystals. Thermal cycling to induce dispersed phase coalescence of the emulsions resulted in desorption of both GMS and GMO from the interface, which we ascribed to solute-solvent hydrogen bonding between the emulsifier molecules and the solvent oil, based on IR spectra. Overall, Pickering crystals were more effective than network crystals for emulsion stabilization. However, the thermal stability of all emulsions was hampered by the diffusion of the molten emulsifiers from the interface.

  16. Microfluidic Production of Multiple Emulsions

    Directory of Open Access Journals (Sweden)

    Goran T. Vladisavljević

    2017-03-01

    Full Text Available Microfluidic devices are promising tools for the production of monodispersed tuneable complex emulsions. This review highlights the advantages of microfluidics for the fabrication of emulsions and presents an overview of the microfluidic emulsification methods including two-step and single-step methods for the fabrication of high-order multiple emulsions (double, triple, quadruple and quintuple and emulsions with multiple and/or multi-distinct inner cores. The microfluidic methods for the formation of multiple emulsion drops with ultra-thin middle phase, multi-compartment jets, and Janus and ternary drops composed of two or three distinct surface regions are also presented. Different configurations of microfluidic drop makers are covered, such as co-flow, T-junctions and flow focusing (both planar and three-dimensional (3D. Furthermore, surface modifications of microfluidic channels and different modes of droplet generation are summarized. Non-confined microfluidic geometries used for buoyancy-driven drop generation and membrane integrated microfluidics are also discussed. The review includes parallelization and drop splitting strategies for scaling up microfluidic emulsification. The productivity of a single drop maker is typically <1 mL/h; thus, more than 1000 drop makers are needed to achieve commercially relevant droplet throughputs of >1 L/h, which requires combining drop makers into twodimensional (2D and 3D assemblies fed from a single set of inlet ports through a network of distribution and collection channels.

  17. Triple Emulsion Drops with An Ultrathin Water Layer: High Encapsulation Efficiency and Enhanced Cargo Retention in Microcapsules.

    Science.gov (United States)

    Choi, Chang-Hyung; Lee, Hyomin; Abbaspourrad, Alireza; Kim, June Hwan; Fan, Jing; Caggioni, Marco; Wesner, Chris; Zhu, Taotao; Weitz, David A

    2016-05-01

    Triple emulsion drops with an ultrathin water layer are developed to achieve high encapsulation efficiency of hydrophobic cargo in a hydrophobic polymeric shell, directly dispersed in water. Furthermore, enhanced retention of volatile hydrophobic cargo is achieved by forming a hydrogel network within this water layer that serves as a physical barrier.

  18. Interfacial protein engineering for spray-dried emulsions - part I: effects on protein distribution and physical properties.

    Science.gov (United States)

    Moisio, Timo; Damerau, Annelie; Lampi, Anna-Maija; Piironen, Vieno; Forssell, Pirkko; Partanen, Riitta

    2014-02-01

    Distribution of protein and oil in aqueous and spray-dried emulsions and the effect of protein cross-linking on emulsion properties and matrix-water interactions were investigated. Sodium caseinate and sunflower oil were used to make emulsions which were spray dried using maltodextrin as a wall material. 3% Na-caseinate concentration showed optimum emulsion and process stability as observed in CLSM images, droplet size data and in the amount of heptane-extractable oil from spray-dried emulsions. Transglutaminase cross-linking prior to emulsification slightly increased the amount of protein both on the oil droplet interface and on the particle surface as confirmed by analysis of continuous phase protein in the feed emulsion and by XPS measurements from the powder surface. DSC and water sorption measurements were used to study the physical state of the matrix. Glass transition occurred between RH 54% and 75% at room temperature and it was not affected by cross-linking.

  19. Some peculiarities of bitumen emulsion modification

    Directory of Open Access Journals (Sweden)

    A. Batyrbayev

    2013-09-01

    Full Text Available Polymer modification of bitumen emulsions obtained from bitumen of domestic production with the use of several commercial emulsifiers was studied. The influence of the polymer modifier concentration on bitumen emulsion physical-mechanical properties was considered. Possibility of obtaining of modified bitumen emulsion with high impact resistance was shown.

  20. Emulsion properties of sunflower (Helianthus annuus) proteins

    NARCIS (Netherlands)

    Gonzalez-Perez, S.; Koningsveld, van G.A.; Vereijken, J.M.; Merck, K.B.; Gruppen, H.; Voragen, A.G.J.

    2005-01-01

    Emulsions were made with sunflower protein isolate (SI), helianthinin, and sunflower albumins (SFAs). Emulsion formation and stabilization were studied as a function of pH and ionic strength and after heat treatment of the proteins. The emulsions were characterized with respect to average droplet si

  1. Boiling heat transfer in dilute emulsions

    CERN Document Server

    Roesle, Matthew Lind

    2013-01-01

    Boiling Heat Transfer in Dilute Emulsions synthesizes recent advances and established understanding on the subject of boiling in dilute emulsions. Experimental results from various sources are collected and analyzed, including contemporary experiments that correlate visualization with heat transfer data. Published models of boiling heat transfer in dilute emulsions, and their implementation, are described and assessed against experimental data.

  2. Microfluidic methods to study emulsion formation

    NARCIS (Netherlands)

    Muijlwijk, Kelly

    2017-01-01

    Emulsions are dispersions of one liquid in another that are commonly used in various products, and methods such as high-pressure homogenisers and colloid mills are used to form emulsions. The size and size distribution of emulsion droplets are important for the final product properties and thus need

  3. Reactions and Polymerizations at the Liquid-Liquid Interface.

    Science.gov (United States)

    Piradashvili, Keti; Alexandrino, Evandro M; Wurm, Frederik R; Landfester, Katharina

    2016-02-24

    Reactions and polymerizations at the interface of two immiscible liquids are reviewed. The confinement of two reactants at the interface to form a new product can be advantageous in terms of improved reaction kinetics, higher yields, and selectivity. The presence of the liquid-liquid interface can accelerate the reaction, or a phase-transfer catalyst is employed to draw the reaction in one phase of choice. Furthermore, the use of immiscible systems, e.g., in emulsions, offers an easy means of efficient product separation and heat dissipation. A general overview on low molecular weight organic chemistry is given, and the applications of heterophase polymerization, occurring at or in proximity of the interface, (mostly) in emulsions are presented. This strategy can be used for the efficient production of nano- and microcarriers for various applications.

  4. Dispersion Polymerization of Polystyrene Particles Using Alcohol as Reaction Medium

    Science.gov (United States)

    Cho, Young-Sang; Shin, Cheol Hwan; Han, Sujin

    2016-02-01

    In this study, monodisperse polystyrene nanospheres were prepared by dispersion polymerization using alcohol as reaction medium to prepare colloidal clusters of the latex beads. Polyvinylpyrrolidone (PVP) and 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTC) were used as dispersion stabilizer and comonomer, respectively. The particle size could be controlled by adjusting the reactant compositions such as the amount of stabilizer, comonomer, and water in the reactant mixture. The size and monodispersity of the polymeric particles could be also controlled by changing the reaction medium with different alcohols other than ethanol or adjusting the polymerization temperature. The synthesized particles could be self-organized inside water-in-oil emulsion droplets by evaporation-driven self-assembly to produce colloidal clusters of the polymeric nanospheres.

  5. Continuous flow analytical microsystems based on low-temperature co-fired ceramic technology. Integrated potentiometric detection based on solvent polymeric ion-selective electrodes.

    Science.gov (United States)

    Ibanez-Garcia, Nuria; Mercader, Manel Bautista; Mendes da Rocha, Zaira; Seabra, Carlos Antonio; Góngora-Rubio, Mario Ricardo; Chamarro, Julian Alonso

    2006-05-01

    In this paper, the low-temperature co-fired ceramics (LTCC) technology, which has been commonly used for electronic applications, is presented as a useful alternative to construct continuous flow analytical microsystems. This technology enables not only the fabrication of complex three-dimensional structures rapidly and at a realistic cost but also the integration of the elements needed to carry out a whole analytical process, such as pretreatment steps, mixers, and detection systems. In this work, a simple and general procedure for the integration of ion-selective electrodes based on liquid ion exchanger is proposed and illustrated by using ammonium- and nitrate-selective membranes. Additionally, a screen-printed reference electrode was easily incorporated into the microfluidic LTCC structure allowing a complete on-chip integration of the potentiometric detection. Analytical features of the proposed systems are presented.

  6. The effect of oil components on the physicochemical properties and drug delivery of emulsions: tocol emulsion versus lipid emulsion.

    Science.gov (United States)

    Hung, Chi-Feng; Fang, Chia-Lang; Liao, Mei-Hui; Fang, Jia-You

    2007-04-20

    An emulsion system composed of vitamin E, coconut oil, soybean phosphatidylcholine, non-ionic surfactants, and polyethylene glycol (PEG) derivatives (referred to as the tocol emulsion) was characterized in terms of its physicochemical properties, drug release, in vivo efficacy, toxicity, and stability. Systems without vitamin E (referred to as the lipid emulsion) and without any oils (referred to as the aqueous micelle system) were prepared for comparison. A lipophilic antioxidant, resveratrol, was used as the model drug for emulsion loading. The incorporation of Brij 35 and PEG derivatives reduced the vesicle diameter to tocol emulsion>lipid emulsion. Treatment of resveratrol dramatically reduced the intimal hyperplasia of the injured vascular wall in rats. There was no significant difference in this reduction when resveratrol was delivered by either emulsion or the aqueous micelle system. The percentages of erythrocyte hemolysis by the emulsions and aqueous micelle system were approximately 0 and approximately 10%, respectively. Vitamin E prevented the aggregation of emulsion vesicles. The mean vesicle size of the tocol emulsion remained unchanged during 30 days at 37 degrees C. The lipid emulsion and aqueous micelle system, respectively, showed 11- and 16-fold increases in vesicle size after 30 days of storage.

  7. Effect of inorganic additives on solutions of nonionic surfactants V: Emulsion stability.

    Science.gov (United States)

    Schott, H; Royce, A E

    1983-12-01

    Electrolytes often break emulsions to which they were added as active ingredients, adjuvants, or impurities. The stability of oil-in-water emulsions containing octoxynol 9 NF as the emulsifier and various added electrolytes was investigated by measuring droplet size, turbidity, and oil separation on storage at various temperatures and in a centrifugal field at 25 degrees. Electrolytes were added to hexadecane emulsions after emulsification (direct addition); alternatively, hexadecane was emulsified in octoxynol 9-electrolyte mixtures (reverse addition). Xylene emulsions were prepared by direct addition only. Hexadecane emulsions containing 0.10% octoxynol 9 were considerably more stable than xylene emulsions containing 0.60% because the surfactant is practically insoluble in hexadecane, but miscible in all proportions with xylene. An emulsifier soluble in the disperse phase as well as the continuous phase evidently forms less stable interfacial films. The electrolytes investigated were sulfuric and hydrochloric acids, magnesium nitrate, and aluminum nitrate, which salt octoxynol 9 in by complexation between its ether groups and their cations; sodium thiocyanate, which salts the surfactant in by destructuring water; and sodium chloride and sodium sulfate, which salt octoxynol 9 out. The addition of these electrolytes at concentrations up to 2 or 3 m to hexadecane emulsions produced fast and extensive creaming, little or no flocculation, no coalescence, and only minor changes in droplet size or turbidity on storage at room temperature. The extent of coalescence during centrifugation was actually reduced by the additives. Such stability is unusual. Droplet size and turbidity depended mainly on octoxynol 9 concentration. The greatest decrease in the former and increase in the latter occurred when the concentration was increased from 0.10 to approximately 0.4%. All emulsions became slightly coarser on storage at 25 degrees. Stability at 50 degrees was impaired by

  8. Detection of coalescing agents in water-borne latex emulsions using an environment sensitive fluorescent probe.

    Science.gov (United States)

    Raja, Tanzeela Nazir; Brouwer, Albert M; Biemans, Koen; Nabuurs, Tijs; Tennebroek, Ronald

    2010-07-30

    In this paper we report the determination of partitioning of coalescing agents (organic co-solvents) in water-borne latex emulsions by means of a fluorescence method. An environment-sensitive fluorescent probe was copolymerized via emulsion polymerization. The presence of organic co-solvents inside the polymer particles is revealed by the photophysical properties of the probe. In particular, the position of the fluorescence emission maximum of co-polymerized can be used to measure the amount of coalescing agent present in the polymer particles. The spectral shifts are shown to be due to the softening of the matrix, rather than to solvation of the probe by the added co-solvent.

  9. Dietary protein and fat emulsions, processed by ultrasound and pulsed magnetic field

    Directory of Open Access Journals (Sweden)

    E. I. Verboloz

    2017-01-01

    Full Text Available For the baking of baked goods in order to save fats, different types of endorsement and protein-fatty emulsions which are used as ingredients in goods and for the protection of metal moulds from burning. Usually emulsion is prepared on bakery enterprises by National State Standard Р 51785–2001, involving mechanical beating up of ingredients. The authors suggested and studied the way of manufacturing of more stable food protein-fatty emulsions using ultrasonic transmitter with rigid neodymium magnets on its thickener. As ingredients, there were applied curd whey diluted with water, unpurified sunflower oil and sunflower phosphatides. Ratio of whey and water is 1:7. Physical effects of ultrasound and field of magnets in contact layer of liquid ingredients being dispersed have increased the viscosity and dispersion of protein-fatty emulsions. Hypothesis of increase of stability and sterility of protein-fatty emulsion by the selection of parameters of magnetic field and power of ultrasound transmitter is confirmed experimentally. Microscopic analysis shows high degree of homogeneity of emulsion under the time of processing 3-4 minutes and intensity of ultrasound 2 W/cm2, that is energetically profitable. There was revealed synergism of influence of physical effects of ultrasound and magnetic field on the durability and steadiness of emulsion to mechanical and temperature effect and also cidal effect, prolonging terms of product using. Manufacture of emulsions by the declared way using the ultrasound and magnetic field of constant neodymium magnets decreases number of injected elements-emulsifiers by 3-4 times or excludes their use at all. Existing piezoelectric ultrasound units as well as neodymium magnets have small sizes and low energy consumption, easily built into the line of continuous manufacture of emulsion for the bread production. Such emulsions are less demanding to the storage and transportation.

  10. A novel continuous two-phase partitioning bioreactor operated with polymeric tubing: Performance validation for enhanced biological removal of toxic substrates.

    Science.gov (United States)

    Tomei, M Concetta; Mosca Angelucci, Domenica; Daugulis, Andrew J

    2017-02-01

    A continuous two-phase partitioning bioreactor (C-TPPB), operated with coiled tubing made of the DuPont polymer Hytrel 8206, was tested for the bioremediation of 4-chlorophenol, as a model toxic compound. The tubing was immersed in the aqueous phase, with the contaminated water flowing tube-side, and an adapted microbial culture suspended in the bioreactor itself, with the metabolic demand of the cells creating a concentration gradient to cause the substrate to diffuse into the bioreactor for biodegradation. The system was operated over a range of loadings (tubing influent concentration 750-1500 mg L(-1)), with near-complete substrate removal in all cases. Distribution of the contaminant at the end of the tests (96 h) highlighted biological removal in the range of 87-95%, while the amount retained in the polymer ranged from ∼1 to 8%. Mass transfer of the substrate across the tubing wall was not limiting, and the polymer demonstrated the capacity to buffer the substrate loadings and to adapt to microbial metabolism. The impact of C-TPPB operation on biomass activity was also investigated by a kinetic characterization of the microbial culture, which showed better resistance to substrate inhibition after C-TPPB operation, thereby confirming the beneficial effect of sub-inhibitory controlled conditions, characteristic of TPPB systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Polar, Functional Diene-Based Materials: Free Radical Polymerization of 2-Cyanomethyl-1,3-Butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Y [Iowa State Univ., Ames, IA (United States)

    2000-09-12

    This thesis presented here focuses on the synthesis of 2-cyanomethyl-l ,3-butadiene and the free-radical polymerization of this monomer. In addition to the bulk, solution and emulsion polymerizations,, copolymerization with styrene and acrylonitrile will also be discussed. The comonomers were chosen due to the potential applications mentioned above. Furthermore, the thermal properties and rnicrostructures of the homopolymers and the copolymers are examined.

  12. Studies on the runaway reaction of ABS polymerization process.

    Science.gov (United States)

    Hu, Kwan-Hua; Kao, Chen-Shan; Duh, Yih-Shing

    2008-11-15

    Taiwan has the largest acrylonitrile-butadiene-styrene (ABS) copolymer production in the world. Preventing on unexpected exothermic reactions and related emergency relief hazard is essential in the safety control of ABS emulsion polymerization. A VSP2 (Vent Sizing Package 2) apparatus is capable of studying both normal and abnormal conditions (e.g., cooling failure, mischarge, etc.) of industrial process. In this study, the scenarios were verified from the following abnormal conditions: loss of cooling, double charge of initiator, overcharge of monomer, without charge of solvent, and external fire. An external fire with constant heating will promote higher self-heat rate and this is recommended as the worst case scenario of emulsion polymerization on butadiene. Cooling failure coupled with bulk system of reactant was determined to be the credible worst case in ABS emulsion polymerization. Finally, the emergency vent sizing based on thermokinetics from VSP associated with DIERS methodology were used for evaluating the vent sizing and compared to that of the industrial plants.

  13. Double emulsions as fat replacers

    NARCIS (Netherlands)

    Oppermann, Anika

    2017-01-01

    The use of double (w1/o/w2) emulsions, in which part of the oil is replaced by small water droplets, is a promising strategy to reduce oil content in food products. For successful applications, (1) significant levels of fat reduction (i.e. significant amounts of water inside the oil droplets) have

  14. Food enrichment with marine phospholipid emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    . The main objective of this study was to explore the possibilities of using marine PL for food enrichment. In order to achieve the objective, the study was divided into 4 stages: i) evaluation of physico-chemical properties of marine PL emulsions, ii) evaluation of hydrolytic and oxidative stability...... of marine PL emulsions, iii) evaluation of non-enzymatic browning reactions in marine PL emulsions, iv) evaluation of sensory properties and oxidative stability of yoghurt enriched with marine PL. The obtained results showed that marine PL have good emulsifying properties and it was feasible to prepare...... marine PL emulsions with and without addition of fish oil. The oxidative stability of marine PL emulsions was significantly influenced by the chemical composition of marine PL used for emulsions preparation. For instance, emulsions with good oxidative stability could be obtained when using raw materials...

  15. EFFECTS OF ω-ACRYLOYL POLY(ETHYLENE OXIDE) MACROMONOMER ON EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND n-BUTYL ACRYLATE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macromonomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxide with diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction terminating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emulsion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containing various concentrations of PEO-A was studied. In all cases stable emulsion coplymerizations of MMA and BA were obtained. The stabilizing effect was found to be dependent on the molecular weight and the feed amount of the macromonomer.

  16. Preparation of sulphonate-containing core/shell latex particles via seeded emulsion copolymerization

    Institute of Scientific and Technical Information of China (English)

    Ji Shuai Wang; Wei Deng; Yun Shen Chen; Cheng You Kan

    2010-01-01

    In this study,P(St-MAA)seed latex particles were first prepared via soap-free emulsion polymerization of styrene(St)and methacrylic acid(MAA),then the seed particles were allowed to swell with St at room temperature,and the P(St-MAA)/P(St-NaSS)core/shell latex particles were then synthesized via seeded emulsion copolymerization of St and sodium styrene sulphonate(NaSS)using AIBN as initiator in the presence of N,N'-methylenebisacrylamide(BAA,water-soluble crosslinker).Results showed that the polymerization could be carried out smoothly when the ratio of BAA to total monomers was less than 3 mol%,the narrow dispersed P(St-MAA)seed particles with the diameter of 150 nm and the P(St-MAA)/P(St-NaSS)core/shell latexes with the particle size of about 200 nm were synthesized.When the 25/75 mole ratio of NaSS/(St+MAA)and 2 mol% of BAA were used in the seeded emulsion polymerization,the resulted P(St-MAA)/P(St-NaSS)latex product showed a low weight loss after water extraction,and the NaSS unit content in the whole particle and in the shell reached 11.7 mol% and 34.6 mol%,respectively.

  17. Dynamic self-assembly of 'living' polymeric chains

    Science.gov (United States)

    Deng, Binghui; Shi, Yunfeng

    2017-01-01

    We report a dynamic self-assembly system of 'living' polymeric chains sustained by chemistry using reactive molecular dynamics simulations. The linear polymeric chains consist of self-assembled nanoparticles connected by metastable linker molecules. As such, the polymeric chains, once assembled, undergo spontaneous dissociation driven by thermodynamics. However, with a continuous supply of linker molecules and the stored chemical energy therein, the polymeric chains can survive and maintain a steady state averaged chain length. These dynamically self-assembled polymeric chains are analogous to biological systems that both are thermodynamically metastable, yet dynamically stable upon continuous influx of matter and energy.

  18. Double emulsions stabilized by a charged complex of modified pectin and whey protein isolate.

    Science.gov (United States)

    Lutz, Rachel; Aserin, Abraham; Wicker, Louis; Garti, Nissim

    2009-08-01

    Double emulsions based on naturally occurring stabilizers for food applications were studied. Two charged biopolymers, whey protein isolate (WPI) and enzymatic modified pectins, interacted in aqueous solution to form a charge-charge complex that was utilized as a hydrophilic polymeric steric stabilizer improving the double emulsion stability. The main factors that influence the interaction between protein and pectin were investigated in relation to double emulsion stability: creaming, coalescence, and water transport between aqueous phases. The pH determined the size of the complex formed. Thus at pH 6, where a soluble complex was obtained between some molecular positively charged patches on the protein and negatively charged fractions of the hydrocolloids, the double emulsion was the most stable. With the smallest droplet size (ca. 15 microm), the lowest creaming, highest yield, and minimized water transport were obtained. The best concentration and ratio to form the soluble complex are 4 wt% WPI and 0.5 wt% pectin (for 30 wt% of the W/O inner phase). The influence of the charge distribution (degree of order of the carboxylic groups) of the pectin on the associated complex was also investigated, and it was found that the more "ordered" pectin (U63) formed the most stable double emulsion against water transport.

  19. Development of O/W emulsions containing Euterpe oleracea extract and evaluation of photoprotective efficacy

    Directory of Open Access Journals (Sweden)

    Cláudia Cecilio Daher

    2014-09-01

    Full Text Available Euterpe oleraceaMart. is a palm tree popularly known as açai, which is primarily found in northern Brazil. The açai's fruits contain anthocyanins, a class of polyphenols to which antioxidant properties have been attributed. The aim of this work was to develop O/W sunscreens emulsions containing açai glycolic extract (AGE and to evaluate both their physical stability and photoprotective efficacy. Emulsions containing AGE and sunscreens were formulated using different types and concentrations of polymeric surfactant (acrylates/C 10-30 alkyl acrylate crosspolymer and sodium polyacrylate. The influence of two rheology modifiers (polyacrylamide (and C13-14/isoparaffin (and Laureth-7 and Carbomer on the stability was also investigated. Physical stability was evaluated by preliminary and accelerated studies. Emulsions with 1.0% sodium polyacrylate were stable and exhibited non-newtonian pseudoplastic behavior and thixotropy. Photoprotective efficacy was evaluated by in vivo Sun Protection Factor (SPF and determination of Protection Factor of UVA (PF-UVA. When AGE was added to the sunscreen emulsion, no significant increase in the in vivo SPF value was observed. The emulsion containing AGE showed PF-UVA = 14.97, 1.69 of the SPF/PF-UVA ratio and a critical wavelength value of 378 nm, and may therefore be considered a sunscreen with UVA and UVB protection.

  20. Effects of visible and UV light on the characteristics and properties of crude oil-in-water (O/W) emulsions.

    Science.gov (United States)

    Genuino, Homer C; Horvath, Dayton T; King'ondu, Cecil K; Hoag, George E; Collins, John B; Suib, Steven L

    2012-04-01

    The effects of visible and UV light on the characteristics and properties of Prudhoe Bay (PB) and South Louisiana (SL) emulsions were investigated to better understand the role of sunlight on the fate of spilled crude oils that form emulsions with a dispersant in the aquatic environment. Before irradiation, crude oil emulsions showed the presence of dispersed crude oil micelles in a continuous water phase and crude oil components floating on the surface. The crude oil micelles decreased in size with irradiation, but emulsions retained their high degree of polydispersity. UV irradiation reduced the stability of emulsions more effectively than visible light. The reduction of micelles size caused the viscosity of emulsions to increase and melting point to decrease. Further, irradiation increased acid concentrations and induced ion formation which lowered the pH and increased the conductivity of emulsions, respectively. Ni and Fe in PB emulsions were extracted from crude oil with UV irradiation, which may provide an efficient process for metal removal. The emulsions were stable toward freeze/thaw cycles and their melting temperatures generally decreased with irradiation. Evidence of ˙OH production existed when emulsions were exposed to UV but not to visible light. The presence of H(2)O(2) enhanced the photodegradation of crude oil. Overall, the changes in emulsion properties were attributed to direct photodegradation and photooxidation of crude oil components.

  1. Dielectric Properties of Flocculated Water-in-Oil Emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Skodvin, T.

    1995-12-31

    When an offshore oil field is near completion, water occupies a large fraction of the available pore volume. Thus, in collecting the oil and gas reserves, one has to deal with a high co-production of either formation- or injected water. This doctoral thesis focuses on the effect of water-in-oil emulsions on the dielectric properties, in particular the effect of flocculation. Various dielectric models are applied to obtain methods for qualitative and quantitative characterization of the flocculated state. Permittivity and measurement of dielectric properties are discussed as a basis for the interpretation of the dielectric properties of the emulsions. Various flocculation models are presented. It is concluded that the dielectric properties of water-in-oil emulsions are strongly influenced by continuously ongoing processes in the system. Because of flocculation and sedimentation the traditional dielectric mixture models cannot satisfactorily predict the dielectric behaviour. The experimentally obtained permittivities for the emulsions can be reproduced by including flocculation in the models and treating the floc aggregates as spheroids or subsystems with dielectric properties given by the degree of flocculation. The models discussed have difficulties reproducing the complete frequency behaviour found experimentally. This is probably because the dielectric relaxation may be influenced by processes not included in the models, such as the effects of dipolar or multipolar interactions between the droplets. For further research it is recommended that rheological and dielectric measurements be combined. 227 refs., 61 figs., 16 tabs.

  2. Lock and key colloids through polymerization-induced buckling of monodisperse silicon oil droplets

    NARCIS (Netherlands)

    Sacanna, S.|info:eu-repo/dai/nl/311471676; Irvine, W.T.M.; Rossi, L.|info:eu-repo/dai/nl/314410376; Pine, D.J.

    2011-01-01

    We have developed a new simple method to fabricate bulk amounts of colloidal spheres with well defined cavities from monodisperse emulsions. Herein, we describe the formation mechanism of ‘‘reactive’’ silicon oil droplets that deform to reproducible shapes via a polymerization-induced buckling

  3. 交联改性苯丙乳液在水性油墨中的应用%Application of styrene-acrylate emulsion modified by crosslinker in water-based ink

    Institute of Scientific and Technical Information of China (English)

    连坤鹏; 朱力勇; 刘润林; 赵英华

    2011-01-01

    分别以邻苯二甲酸二烯丙酯(DAP)、杂环甲基丙烯酸酯单体(TRM WAM Ⅲ)和乙酰乙酸基甲基丙烯酸乙酯(AAEMA)作为传统苯丙乳液的交联改性剂,采用预乳化半连续乳液聚合法制备交联改性苯丙乳液;然后以此为连接料,制备水性油墨.研究了传统苯丙乳液、交联改性苯丙乳液以及进口同类产品对水性油墨的摩擦牢度、稳定性能和耐水性能等影响.结果表明:交联改性苯丙乳液均具有较好的钙离子稳定性和冻融稳定性;由TRM WAM Ⅲ改性苯丙乳液配制而成的水性油墨,具有相对较好的摩擦牢度(干态、湿态摩擦等级分别为9.0、6.0)、稳定性能、耐水性能(耐水时间25 s)、光泽和着色力(100%);该改性乳液的综合性能已接近进口同类产品(JONCRYL 74-A),并且其在水性油墨中的应用具有可行性.%With diallyl phthalate(DAP),heterocyclic methacrylate monomer(TRM WAM Ⅲ),and acetoacetatebased ethyl methacrylate (AAEMA) as cross linker of traditional styrene-acrylate emulsion respectively, a styreneacrylate emulsion modified by crosslinker was prepared by pre-emulsified semi-continuous emulsion polymerization.Then a water-based ink was prepared with styrene-acrylate emulsion modified by crosslinker as ink vehicle. The influences of some emulsions such as traditional styrene-acrylate emulsion,styrene-acrylate emulsion modified by crosslinker and similar import product were investigated on some properties such as rubbing fastness,stability and water resistance of water-based ink. The results showed that the styrene-acrylate emulsion modified by crosslinker had better calcium ion stability and freeze-thaw stability. The water-based ink ,which was made from styreneacrylate emulsion modified by TRM WAM Ⅲ ,had relatively better rubbing fastness(dry or wet rubbing grades at 9.0 or 6.0) ,stability,water resistance(water resistance time at 25 s) ,luster and tinting strength(100%). The styreneacrylate emulsion

  4. On the Viscosity of Emulsions

    CERN Document Server

    Kroy, K; Djabourov, M; Kroy, Klaus; Capron, Isabelle; Djabourov, Madeleine

    1999-01-01

    Combining direct computations with invariance arguments, Taylor's constitutive equation for an emulsion can be extrapolated to high shear rates. We show that the resulting expression is consistent with the rigorous limits of small drop deformation and that it bears a strong similarity to an a priori unrelated rheological quantity, namely the dynamic (frequency dependent) linear shear response. More precisely, within a large parameter region the nonlinear steady-state shear viscosity is obtained from the real part of the complex dynamic viscosity, while the first normal stress difference is obtained from its imaginary part. Our experiments with a droplet phase of a binary polymer solution (alginate/caseinate) can be interpreted by an emulsion analogy. They indicate that the predicted similarity rule generalizes to the case of moderately viscoelastic constituents that obey the Cox-Merz rule.

  5. Conducting Polymeric Materials

    DEFF Research Database (Denmark)

    Hvilsted, Søren

    2016-01-01

    The overall objective of this collection is to provide the most recent developments within the various areas of conducting polymeric materials. The conductivity of polymeric materials is caused by electrically charged particles, ions, protons and electrons. Materials in which electrons...

  6. Layered Polymeric Optical Systems Using Continuous Coextrusion

    Science.gov (United States)

    2009-01-01

    band[13]. The possibility of fabricating tunable photonic crystals was explored using thermoplastic polyurethane (TPU, n = 1.55) layered against Pebax... losses within the cavity reflection band. Typical emission spectra are shown in Figure 9. The thickness of the dielectric layer determines the spacing...fabrication of refractive index patterns, including gradients and superlattices. The periodic dielectric nature leads to interference effects

  7. Photoacoustic analysis of dental resin polymerization

    Science.gov (United States)

    Coloiano, E. C. R.; Rocha, R.; Martin, A. A.; da Silva, M. D.; Acosta-Avalos, D.; Barja, P. R.

    2005-06-01

    In this work, we use the photoacoustic technique to monitor the curing process of diverse dental materials, as the resins chemically activated (RCA). The results obtained reveal that the composition of a determined RCA significantly alters its activation kinetics. Photoacoustic data also show that temperature is a significant parameter in the activation kinetics of resins. The photoacoustic technique was also applied to evaluate the polymerization kinetics of photoactivated resins. Such resins are photoactivated by incidence of continuous light from a photodiode. This leads to the polymerization of the resin, modifying its thermal properties and, consequently, the level of the photoacoustic signal. Measurements show that the polymerization of the resin changes the photoacoustic signal amplitude, indicating that photoacoustic measurements can be utilized to monitor the polymerization kinetic and the degree of polymerization of photoactivated dental resins.

  8. Self-breaking retarded acid emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Scherubel, G.A.

    1979-02-20

    A subterranean formation is acidized with an acid-in-oil emulsion consisting of an aqueous acidizing solution, an oil, an alkyl C/sub 8/ to C/sub 18/ primary fatty amine, and at least one diethanolamide of at least one C/sub 8/ to C/sub 18/ fatty acid. The present invention is an improved acid-in-oil acidizing emulsion, and acidizing method such as an emulsion, the emulsion being of the type containing an effective amount of at least one C/sub 8/ to C/sub 18/ primary amine as a cationic surfactant to increase the normal reaction. The diethanolamine is a nonionic surfactant which causes the emulsion to break as the acidizing capacity of the emulsion becomes substantially depleted, i.e., spent, on the formation. 41 claims.

  9. Influence of maltodextrin dextrose equivalent value on rheological and dispersion properties of sunflower oil in water emulsions

    Directory of Open Access Journals (Sweden)

    Dokić Petar P.

    2004-01-01

    Full Text Available Effect of dextrose equivalent (DE of maltodextrin present in continuous phase on flow along with dispersion properties of sunflower oil in water emulsions has been investigated. Both, rheological and disperse characteristics of the emulsions were greatly influenced by continuous phase viscosity and thus by the DE value of maltodextrin.. The smaller DE value the greater high shear viscosity and the smaller the droplet size. Irrespective of the amount and DE value of maltodextrin used was, all the emulsions showed a pseudoplastic behaviour.

  10. Oil-in-water emulsions flow through constricted micro-capillarities

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, Oswaldo Robles; Carvalho, Marcio da Silveira [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. of Mechanical Engineering

    2010-07-01

    The effect of the oil concentration and the drop size distribution on the characteristics of the flow of an emulsion through a constricted capillary was experimentally analyzed and quantified by the ratio of the pressure drop of the continuous phase flow to the pressure drop of the emulsion flow, at the same flow rate. The results confirm that the ratio between the capillary constriction diameter and the oil drop size is one of the most important parameters for this flow. For large oil drop size emulsions, the deformation of the drop as it flows through the constriction leads to a high extra pressure drop at low capillary numbers. For small oil drop size emulsions, the extra pressure drop is a function of the viscosity ratio and the disperse phase concentration. (author)

  11. Controlling Pickering Emulsion Destabilisation: A Route to Fabricating New Materials by Phase Inversion

    Directory of Open Access Journals (Sweden)

    Catherine P. Whitby

    2016-07-01

    Full Text Available The aim of this paper is to review the key findings about how particle-stabilised (or Pickering emulsions respond to stress and break down. Over the last ten years, new insights have been gained into how particles attached to droplet (and bubble surfaces alter the destabilisation mechanisms in emulsions. The conditions under which chemical demulsifiers displace, or detach, particles from the interface were established. Mass transfer between drops and the continuous phase was shown to disrupt the layers of particles attached to drop surfaces. The criteria for causing coalescence by applying physical stress (shear or compression to Pickering emulsions were characterised. These findings are being used to design the structures of materials formed by breaking Pickering emulsions.

  12. Synthesis and characterization of nano-SiO{sub 2} modified fluorine-containing polyacrylate emulsifier-free emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jianhua, E-mail: zhoujianh@21cn.com [College of Resource and Environment, Shaanxi University of Science and Technology, Xi’an 710021 (China); Shaanxi Research Institute of Agricultural Products Processing Technology, Xi’an 710021 (China); Chen, Xin; Duan, Hao; Ma, Jianzhong; Ma, Yurong [College of Resource and Environment, Shaanxi University of Science and Technology, Xi’an 710021 (China)

    2015-03-15

    Graphical abstract: Nano-SiO{sub 2} modified fluorine-containing polyacrylate emulsifier-free emulsion was synthesized by emulsifier-free emulsion polymerization and sol–gel process using ethyl silicate as precursor for nano-SiO{sub 2}. - Highlights: • Nano-SiO{sub 2} modified fluorine-containing polyacrylate emulsifier-free emulsion was successfully synthesized by emulsion polymerization using surfmer and sol–gel process. • The contact angle results showed that the finished fabric had an excellent water and oil repellency. • The nano-SiO{sub 2} modified fluorine-containing polyacrylate emulsifier-free emulsion proved to be highly solvent-resistant and water-resistant. • The transmission electron microscopy (TEM) indicated that the nano-SiO{sub 2} presented on the surface of latex particles. • The atomic force microscope (AFM) and energy dispersive X-ray spectrometer (EDX) confirmed that the hybrid film had a rough surface and the organic fluorine segment could migrate onto the film–air interface. - Abstract: Nano-SiO{sub 2} modified fluorine-containing polyacrylate emulsifier-free emulsion, consisting of methyl methacrylate, butyl acrylate, dodecafluoroheptyl methacrylate and ethyl silicate, was successfully synthesized by emulsion polymerization using surfmer and sol–gel process. When increasing ethyl silicate content, the latex centrifugal stability decreased, and the latex particle size increased. The contact angle results showed that the finished fabric had an excellent water and oil repellency. Furthermore, compared with fluorine-containing polyacrylate emulsifier-free emulsion, the obtained nano-SiO{sub 2} modified fluorine-containing polyacrylate emulsifier-free emulsion proved to be highly solvent-resistant and water-resistant. In addition, the transmission electron microscopy (TEM) indicated that the nano-SiO{sub 2} presented on the surface of latex particles. The atomic force microscope (AFM) and energy dispersive X-ray spectrometer

  13. Pickering emulsions for skin decontamination.

    Science.gov (United States)

    Salerno, Alicia; Bolzinger, Marie-Alexandrine; Rolland, Pauline; Chevalier, Yves; Josse, Denis; Briançon, Stéphanie

    2016-08-01

    This study aimed at developing innovative systems for skin decontamination. Pickering emulsions, i.e. solid-stabilized emulsions, containing silica (S-PE) or Fuller's earth (FE-PE) were formulated. Their efficiency for skin decontamination was evaluated, in vitro, 45min after an exposure to VX, one of the most highly toxic chemical warfare agents. Pickering emulsions were compared to FE (FE-W) and silica (S-W) aqueous suspensions. PE containing an oil with a similar hydrophobicity to VX should promote its extraction. All the formulations reduced significantly the amount of VX quantified on and into the skin compared to the control. Wiping the skin surface with a pad already allowed removing more than half of VX. FE-W was the less efficient (85% of VX removed). The other formulations (FE-PE, S-PE and S-W) resulted in more than 90% of the quantity of VX removed. The charge of particles was the most influential factor. The low pH of formulations containing silica favored electrostatic interactions of VX with particles explaining the better elimination from the skin surface. Formulations containing FE had basic pH, and weak interactions with VX did not improve the skin decontamination. However, these low interactions between VX and FE promote the transfer of VX into the oil droplets in the FE-PE.

  14. Impact of acoustic cavitation on food emulsions.

    Science.gov (United States)

    Krasulya, Olga; Bogush, Vladimir; Trishina, Victoria; Potoroko, Irina; Khmelev, Sergey; Sivashanmugam, Palani; Anandan, Sambandam

    2016-05-01

    The work explores the experimental and theoretical aspects of emulsification capability of ultrasound to deliver stable emulsions of sunflower oil in water and meat sausages. In order to determine optimal parameters for direct ultrasonic emulsification of food emulsions, a model was developed based on the stability of emulsion droplets in acoustic cavitation field. The study is further extended to investigate the ultrasound induced changes to the inherent properties of raw materials under the experimental conditions of sono-emulsification.

  15. An overview of Preparation, Evaluation and Applications of Multiple Emulsions

    Directory of Open Access Journals (Sweden)

    Sandip Prajapati

    2013-04-01

    Full Text Available Multiple emulsions are also known as emulsions of emulsions, liquid membrane system or double emulsion. Multiple emulsions are polydispersed systems where both oil in water & water in oil emulsions exist simultaneously. This review focuses on preparation, characterization and potential applications of multiple emulsions. Multiple emulsions can be classified as water-in oil-in water (W/O/W or oil-in-water-in-oil (O/W/O emulsions. This review described five methods to prepare multiple emulsions viz. two-step emulsification method, modified two-step emulsification method, phase inversion method, membrane emulsification & micro channel emulsification method. The Multiple emulsion is characterized by average globule size & size distribution, area of interfaces, number of globules, rheological evaluation, zeta potential, percentage drug entrapment, In-vitro drug release. Multiple emulsions have been proposed to have numerous uses including their use as prolonged drug delivery system.

  16. How emulsions composition and structure affect sensory perception of low-viscosity model emulsions

    NARCIS (Netherlands)

    Vingerhoeds, M.H.; Wijk, de R.A.; Zoet, F.D.; Nixdorf, R.R.; Aken, van G.A.

    2008-01-01

    The oral residence time of low-viscosity emulsions, like milk, is relatively short. Despite this short residence time, people can easily perceive differences between these emulsions. Our research is dedicated to unravel the oral behaviour of emulsions in relation to sensory perception. The aim of

  17. How emulsions composition and structure affect sensory perception of low-viscosity model emulsions

    NARCIS (Netherlands)

    Vingerhoeds, M.H.; Wijk, de R.A.; Zoet, F.D.; Nixdorf, R.R.; Aken, van G.A.

    2008-01-01

    The oral residence time of low-viscosity emulsions, like milk, is relatively short. Despite this short residence time, people can easily perceive differences between these emulsions. Our research is dedicated to unravel the oral behaviour of emulsions in relation to sensory perception. The aim of th

  18. Preparation of an Adhesive in Emulsion for Maxillofacial Prosthetic

    Directory of Open Access Journals (Sweden)

    Joaquín Palacios-Alquisira

    2010-10-01

    Full Text Available Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA‑MMA‑EA and (AA‑MMA‑2EHA with different molar ratios. The formulation based on (AA‑MMA‑2EHA with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives.

  19. Preparation of an Adhesive in Emulsion for Maxillofacial Prosthetic

    Science.gov (United States)

    Sánchez-García, Judith A.; Ortega, Alejandra; Barceló-Santana, Federico H.; Palacios-Alquisira, Joaquín

    2010-01-01

    Maxillofacial prostheses is a dental medicine specialty aimed at restoring anatomical facial defects caused by cancer, trauma or congenital malformations through an artificial device, which is commonly attached to the skin with the help of an adhesive. The purpose of our research was to develop a pressure-sensitive adhesive (PSA) based on acrylic monomers, characterizing and determining its drying kinetics, that is to say the time it takes to lose 50 to 90% of its moisture. The adhesive synthesis was realized by means of emulsion polymerization; the composition of formulations was: (AA-MMA-EA) and (AA-MMA-2EHA) with different molar ratios. The formulation based on (AA-MMA-2EHA) with 50 w% of solids, presented good adhesive properties such as tack, bond strength, and short drying time. We propose this formulation as a PSA, because it offers an alternative for systemically compromised patients, by less irritation compared to organic solvent-based adhesives. PMID:21152308

  20. Synthesis and Optical Performances of a Waterborne Polyurethane-Based Polymeric Dye

    Directory of Open Access Journals (Sweden)

    Xianhai Hu

    2015-01-01

    Full Text Available A waterborne polyurethane-based polymeric dye (WPU-CFBB was synthesized by anchoring 1, 4-bis(methylaminoanthraquinone (CFBB to waterborne polyurethane chains. The number molecular weight, glass transition temperature, and average emulsion particle size for the polymeric dye were determined, respectively. This polymeric dye exhibited intriguing optical behaviors. The polymeric dye engendered two new absorption bands centered at about 520 nm and 760 nm if compared with CFBB in UV-vis spectra. The 760 nm peak showed hypsochromic shift with the decrease of average particle sizes. The polymeric dye dramatically demonstrated both hypsochromic and bathochromic effects with increasing temperature. The fluorescence intensity of the polymeric dye was much higher than that of CFBB. It was found that the fluorescence intensities would be enhanced from 20°C to 40°C and then decline from 40°C to 90°C. The fluorescence of the polymeric dye emulsion was very stable and was not sensitive to quenchers.

  1. On the transport of emulsions in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Cortis, Andrea; Ghezzehei, Teamrat A.

    2007-06-27

    Emulsions appear in many subsurface applications includingbioremediation, surfactant-enhanced remediation, and enhancedoil-recovery. Modeling emulsion transport in porous media is particularlychallenging because the rheological and physical properties of emulsionsare different from averages of the components. Current modelingapproaches are based on filtration theories, which are not suited toadequately address the pore-scale permeability fluctuations and reductionof absolute permeability that are often encountered during emulsiontransport. In this communication, we introduce a continuous time randomwalk based alternative approach that captures these unique features ofemulsion transport. Calculations based on the proposed approach resultedin excellent match with experimental observations of emulsionbreakthrough from the literature. Specifically, the new approach explainsthe slow late-time tailing behavior that could not be fitted using thestandard approach. The theory presented in this paper also provides animportant stepping stone toward a generalizedself-consistent modeling ofmultiphase flow.

  2. A Dewetting Model for Double-Emulsion Droplets

    Directory of Open Access Journals (Sweden)

    Zhanxiao Kang

    2016-11-01

    Full Text Available The evolution of double-emulsion droplets is of great importance for the application of microdroplets and microparticles. We study the driving force of the dewetting process, the equilibrium configuration and the dewetting time of double-emulsion droplets. Through energy analysis, we find that the equilibrium configuration of a partial engulfed droplet depends on a dimensionless interfacial tension determined by the three relevant interfacial tensions, and the engulfing part of the inner phase becomes larger as the volume of the outer phase increases. By introducing a dewetting boundary, the dewetting time can be calculated by balancing the driving force, caused by interfacial tensions, and the viscous force. Without considering the momentum change of the continuous phase, the dewetting time is an increasing function against the viscosity of the outer phase and the volume ratio between the outer phase and inner phase.

  3. On the transport of emulsions in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Cortis, Andrea; Ghezzehei, Teamrat A.

    2007-06-27

    Emulsions appear in many subsurface applications includingbioremediation, surfactant-enhanced remediation, and enhancedoil-recovery. Modeling emulsion transport in porous media is particularlychallenging because the rheological and physical properties of emulsionsare different from averages of the components. Current modelingapproaches are based on filtration theories, which are not suited toadequately address the pore-scale permeability fluctuations and reductionof absolute permeability that are often encountered during emulsiontransport. In this communication, we introduce a continuous time randomwalk based alternative approach that captures these unique features ofemulsion transport. Calculations based on the proposed approach resultedin excellent match with experimental observations of emulsionbreakthrough from the literature. Specifically, the new approach explainsthe slow late-time tailing behavior that could not be fitted using thestandard approach. The theory presented in this paper also provides animportant stepping stone toward a generalizedself-consistent modeling ofmultiphase flow.

  4. Bioreactor droplets from liposome-stabilized all-aqueous emulsions

    Science.gov (United States)

    Dewey, Daniel C.; Strulson, Christopher A.; Cacace, David N.; Bevilacqua, Philip C.; Keating, Christine D.

    2014-08-01

    Artificial bioreactors are desirable for in vitro biochemical studies and as protocells. A key challenge is maintaining a favourable internal environment while allowing substrate entry and product departure. We show that semipermeable, size-controlled bioreactors with aqueous, macromolecularly crowded interiors can be assembled by liposome stabilization of an all-aqueous emulsion. Dextran-rich aqueous droplets are dispersed in a continuous polyethylene glycol (PEG)-rich aqueous phase, with coalescence inhibited by adsorbed ~130-nm diameter liposomes. Fluorescence recovery after photobleaching and dynamic light scattering data indicate that the liposomes, which are PEGylated and negatively charged, remain intact at the interface for extended time. Inter-droplet repulsion provides electrostatic stabilization of the emulsion, with droplet coalescence prevented even for submonolayer interfacial coatings. RNA and DNA can enter and exit aqueous droplets by diffusion, with final concentrations dictated by partitioning. The capacity to serve as microscale bioreactors is established by demonstrating a ribozyme cleavage reaction within the liposome-coated droplets.

  5. Metallic nanoshells on porphyrin-stabilized emulsions

    Science.gov (United States)

    Wang, Haorong; Song, Yujiang; Shelnutt, John A; Medforth, Craig J

    2013-10-29

    Metal nanostructures formed by photocatalytic interfacial synthesis using a porphyrin-stabilized emulsion template and the method for making the nanostructures. Catalyst-seeded emulsion droplets are employed as templates for hollow-nanoshell growth. The hollow metal nanospheres may be formed with or without inclusions of other materials.

  6. Suppression of Ostwald ripening in active emulsions

    Science.gov (United States)

    Zwicker, David; Hyman, Anthony A.; Jülicher, Frank

    2015-07-01

    Emulsions consisting of droplets immersed in a fluid are typically unstable since they coarsen over time. One important coarsening process is Ostwald ripening, which is driven by the surface tension of the droplets. Stability of emulsions is relevant not only in complex fluids but also in biological cells, which contain liquidlike compartments, e.g., germ granules, Cajal bodies, and centrosomes. Such cellular systems are driven away from equilibrium, e.g., by chemical reactions, and thus can be called active emulsions. In this paper, we study such active emulsions by developing a coarse-grained description of the droplet dynamics, which we analyze for two different chemical reaction schemes. We first consider the simple case of first-order reactions, which leads to stable, monodisperse emulsions in which Ostwald ripening is suppressed within a range of chemical reaction rates. We then consider autocatalytic droplets, which catalyze the production of their own droplet material. Spontaneous nucleation of autocatalytic droplets is strongly suppressed and their emulsions are typically unstable. We show that autocatalytic droplets can be nucleated reliably and their emulsions stabilized by the help of chemically active cores, which catalyze the production of droplet material. In summary, different reaction schemes and catalytic cores can be used to stabilize emulsions and to control their properties.

  7. Altering Emulsion Stability with Heterogeneous Surface Wettability

    Science.gov (United States)

    Meng, Qiang; Zhang, Yali; Li, Jiang; Lammertink, Rob G. H.; Chen, Haosheng; Tsai, Peichun Amy

    2016-06-01

    Emulsions–liquid droplets dispersed in another immiscible liquid–are widely used in a broad spectrum of applications, including food, personal care, agrochemical, and pharmaceutical products. Emulsions are also commonly present in natural crude oil, hampering the production and quality of petroleum fuels. The stability of emulsions plays a crucial role in their applications, but controlling the stability without external driving forces has been proven to be difficult. Here we show how heterogeneous surface wettability can alter the stability and dynamics of oil-in-water emulsions, generated by a co-flow microfluidic device. We designed a useful methodology that can modify a micro-capillary of desired heterogeneous wettability (e.g., alternating hydrophilic and hydrophobic regions) without changing the hydraulic diameter. We subsequently investigated the effects of flow rates and heterogeneous wettability on the emulsion morphology and motion. The experimental data revealed a universal critical timescale of advective emulsions, above which the microfluidic emulsions remain stable and intact, whereas below they become adhesive or inverse. A simple theoretical model based on a force balance can be used to explain this critical transition of emulsion dynamics, depending on the droplet size and the Capillary number–the ratio of viscous to surface effects. These results give insight into how to control the stability and dynamics of emulsions in microfluidics with flow velocity and different wettability.

  8. Self-breaking retarded acid emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Scherubel, G.A.

    1980-10-07

    An acid-in-oil acidizing emulsion, and acidizing method use an emulsion of the type containing an effective amount of at least one C8 to C18 primary amine as a cationic surfactant to increase the normal reaction time of the acid with an acid soluble formation. The composition and method aspects are both affected by the inclusion in the emulsion of an effective amount of a nonionic surfactant. Specifically, the emulsion resides in a composition for acidizing a subterranean formation, the composition being of the acidizing solution-in-oil emulsion type containing an effective amount of an alkyl C8 to C18 primary amine to reduce the normal reaction rate of the emulsion, and an effective amount of at least one diethanolamide of at least one C8 to C18 fatty acid so that the emulsion substantially completely breaks when the acidizing capacity of the emulsion becomes substantially spent as a result of reaction with such a formation. 19 claims.

  9. Stability of Water/Poly(ethylene oxide)43-b-poly(ε-caprolactone)14/Cyclohexanone Emulsions Involves Water Exchange between the Core and the Bulk.

    Science.gov (United States)

    Flores, Mario E; Martínez, Francisco; Olea, Andrés F; Shibue, Toshimichi; Sugimura, Natsuhiko; Nishide, Hiroyuki; Moreno-Villoslada, Ignacio

    2015-12-31

    The formation of emulsions upon reverse self-association of the monodisperse amphiphilic block copolymer poly(ethylene oxide)43-b-poly(ε-caprolactone)14 in cyclohexanone is reported. Such emulsions are not formed in toluene, chloroform, or dichloromethane. We demonstrate by magnetic resonance spectroscopy the active role of the solvent on the stabilization of the emulsions. Cyclohexanone shows high affinity for both blocks, as predicted by the Hansen solubility parameters, so that the copolymer chains are fully dissolved as monomeric chains. In addition, the solvent is able to produce hydrogen bonding with water molecules. Water undergoes molecular exchange between water molecules associated with the polymer and water molecules associated with the solvent, dynamics of major importance for the stabilization of the emulsions. Association of polymeric chains forming reverse aggregates is induced by water over a concentration threshold of 5 wt %. Reverse copolymer aggregates show submicron average hydrodynamic diameters, as seen by dynamic light scattering, depending on the polymer and water concentration.

  10. Internal flow in droplets within a concentrated emulsion flowing in a microchannel

    Science.gov (United States)

    Leong, Chia Min; Gai, Ya; Tang, Sindy K. Y.

    2016-11-01

    Droplet microfluidics has enabled a wide variety of high-throughput biotechnical applications through the use of monodisperse micro-droplets as bioreactors. Previous fluid dynamics studies of droplet microfluidics have focused on single droplets or emulsions at low volume fractions. The study of concentrated emulsions at high volume fractions is important for further increasing the throughput of droplet microfluidics, but the fluid dynamics of such emulsions in confined microchannels is not well understood. This paper describes the use of microscopic particle image velocimetry to quantify the flow inside individual droplets within a concentrated emulsion having volume fraction φ ˜ 85% flowing as a monolayer in a straight microfluidic channel. The effects of confinement (namely, the number of rows of droplets across the width of the channel) and viscosity ratio on the internal flow patterns inside the drops at a fixed capillary number of 10-3 and a Reynolds number of 10-2 to 10-1 are studied. The results show that rotational structures inside the droplets always exist and are independent of viscosity ratio for the conditions tested. The structures depend on droplet mobility, the ratio of the velocity of the droplet to the velocity of the continuous phase. These values, in turn, depend on the confinement of the emulsion and the location of the droplets in the channel. Although this work presents two-dimensional measurements at the mid-height of the microchannel only, the results reveal flow patterns that are never described before in single drops or dilute emulsions.

  11. Superheated emulsions: neutronics and thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    d`Errico, F. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari]|[Yale Univ., New Haven, CT (United States). School of Medicine; Curzio, G. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari; Nath, R. [Yale Univ., New Haven, CT (United States). School of Medicine; Apfel, R.E. [Yale Univ., New Haven, CT (United States). Dept. of Mechanical Engineering; Dietz, E.; Guldbakke, S.; Siebert, B.R.L. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Egger, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Gualdrini, G.F. [ENEA, Bologna (Italy)

    1997-09-01

    The results of some recent theoretical and experimental investigations on the physics of superheated emulsions are presented. Computational fluid thermodynamics allowed for a detailed description of the temporal and spatial history of the energy deposition process by a charged particle in a superheated liquid. Despite the assumptions it is based upon, this model gives information in agreement with experimental data on bubble nucleation. The experimental findings concern the role of interfacial reactions between drops and emulsifier, the existence of inhibition temperatures for the detector`s response, and the progressive sensitisation to protons. (author).

  12. Aging mechanism in model Pickering emulsion

    Science.gov (United States)

    Fouilloux, Sarah; Malloggi, Florent; Daillant, Jean; Thill, Antoine

    We study the stability of a model Pickering emulsion system. A special counter-flow microfluidics set-up was used to prepare monodisperse Pickering emulsions, with oil droplets in water. The wettability of the monodisperse silica nanoparticles (NPs) could be tuned by surface grafting and the surface coverage of the droplets was controlled using the microfluidics setup. A surface coverage as low as 23$\\%$ is enough to stabilize the emulsions and we evidence a new regime of Pickering emulsion stability where the surface coverage of emulsion droplets of constant size increases in time, in coexistence with a large amount of dispersed phase. Our results demonstrate that the previously observed limited coalescence regime where surface coverage tends to control the average size of the final droplets must be put in a broader perspective.

  13. Food enrichment with marine phospholipid emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    Many studies have shown that marine phospholipids (PL) provide more advantages than fish oil. They seem to have better bioavailability, better resistance towards oxidation and higher content of eicosapentaenoic acids and docosahexaenoic acids than fish oil, which essentially contains triglycerides...... marine PL emulsions with and without addition of fish oil. The oxidative stability of marine PL emulsions was significantly influenced by the chemical composition of marine PL used for emulsions preparation. For instance, emulsions with good oxidative stability could be obtained when using raw materials...... with high purity, low fish oil content and high PL, cholesterol and α-tocopherol content. In addition, non-enzymatic browning reactions may also affect the oxidative stability of the marine PL emulsion. These reactions included Strecker degradation and pyrrolization, and their occurrence were due...

  14. Heat Transfer in Boiling Dilute Emulsion with Strong Buoyancy

    Science.gov (United States)

    Freeburg, Eric Thomas

    Little attention has been given to the boiling of emulsions compared to that of boiling in pure liquids. The advantages of using emulsions as a heat transfer agent were first discovered in the 1970s and several interesting features have since been studied by few researchers. Early research focuses primarily on pool and flow boiling and looks to determine a mechanism by which the boiling process occurs. This thesis looks at the boiling of dilute emulsions in fluids with strong buoyant forces. The boiling of dilute emulsions presents many favorable characteristics that make it an ideal agent for heat transfer. High heat flux electronics, such as those seen in avionics equipment, produce high heat fluxes of 100 W/cm2 or more, but must be maintained at low temperatures. So far, research on single phase convection and flow boiling in small diameter channels have yet to provide an adequate solution. Emulsions allow the engineer to tailor the solution to the specific problem. The fluid can be customized to retain the high thermal conductivity and specific heat capacity of the continuous phase while enhancing the heat transfer coefficient through boiling of the dispersed phase component. Heat transfer experiments were carried out with FC-72 in water emulsions. FC-72 has a saturation temperature of 56 °C, far below that of water. The parameters were varied as follows: 0% ≤ epsilon ≤ 1% and 1.82 x 1012 ≤ RaH ≤ 4.42 x 1012. Surface temperatures along the heated surface reached temperature that were 20 °C in excess of the dispersed phase saturation temperature. An increase of ˜20% was seen in the average Nusselt numbers at the highest Rayleigh numbers. Holography was used to obtain images of individual and multiple FC-72 droplets in the boundary layer next to the heated surface. The droplet diameters ranged from 0.5 mm to 1.3 mm. The Magnus effect was observed when larger individual droplets were injected into the boundary layer, causing the droplets to be pushed

  15. The Study of Fluoroacrylate Modified Hydroxyl Acrylic Emulsion%氟改性羟基丙烯酸乳液的研究

    Institute of Scientific and Technical Information of China (English)

    贺亮洪; 梁亮; 曾凡初; 齐增清; 弋天宝

    2011-01-01

    以丙烯酸全氟烷基酯(Zonyl TM)为功能单体,阴离子、非离子乳化剂为复合乳化剂,采用预乳化半连续乳液聚合法合成了氟改性羟基丙烯酸乳液,并将合成的乳液与氨基树脂制得性能优异的丙烯酸氨基清漆.系统地研究了氟单体、交联单体、丙烯酸含量及苯乙烯和甲基丙烯酸甲酯的配比等因素对涂膜性能的影响,对影响清漆的混容性及贮存稳定性的各因素进行了讨论.此外,含氟乳胶膜对水的接触角及红外光谱表征结果表明,Zonyl TM有效参与了共聚反应,提高了涂膜的耐水性及耐化学品性.%Fluoroacrylate modified hydroxyl acrylic emulsion was synthesized by pre - emulsion and semi - continuous emulsion polymerization, with perfluoroalky acrylate(Zonyl TM) as functional monomer, and a mixture of anionic and nonionic emulsifier as emulsifier, which was then used together with melamine resin to give high performance acrylic - melamine varnish. The effects of fluorine - containing monomer, crosslinking monomer, acrylic acid amount and the ratio of styrene and methyl methacrylate on the film performance were systematically investigated. And the factors influencing the compatibility and storage stability of varnish were discussed. Additionally, water contact and the FT - IR of the fluorine - containing emulsion film were analyzed. The results showed that Zonyl TM was effectively involved in the eopolymerization and improved the water resistance and chemical resistance of'the film.

  16. Synthesis of Self - Crosslinking Modified Styrene -Acrylate Emulsion and Its Performance for Wood Paints%木器漆用自交联改性苯丙乳液的合成以及性能研究

    Institute of Scientific and Technical Information of China (English)

    李顺; 兰支利; 尹笃林; 邓靖; 黄波

    2012-01-01

    Using styrene,butyl acrylate,acrylic acid,HEMA,N -MA.DAAM and siloxane monomer as raw materials, ammonium persulfate(APS) as initiator to prepare the title self - crosslinking modified styrene - acrylate emulsion through pre - emulsification technology and semi - continuous seed emulsion polymerization process. The influences of the amount and percentage of crosslinking monomers, amount of siloxane monomer,and amount of initiator and temperature on the emulsion performance were discussed. The results showed that the better comprehensive performance of emulsion could be obtained when the amount of crosslinking monomer was 5% ,m(DAAM): m(N - MA) =3:2,amount of siloxane monomer between 0. 5% to 1. 0% , initiator 0. 4% and polymerization temperature between 83-87 ℃.%以苯乙烯、丙烯酸丁酯、丙烯酸、甲基丙烯酸羟乙酯、N-羟甲基丙烯酰胺(N -MA)、双丙酮丙烯酰胺(DAAM)及有机硅单体为主要原料,过硫酸铵(APS)为引发剂,采用预乳化工艺和半连续种子乳液聚合法制备自交联改性苯丙乳液.考察了交联单体用量、交联单体配比、有机硅单体用量、引发剂用量以及聚合温度等因素对乳液性能的影响.研究结果表明:当交联单体用量为单体总量的5%,m(DAAM):m(N - MA) =3:2,有机硅加入量为0.5%~1.O%,引发剂用量为单体用量的0.4%,聚合温度为83~87℃时,所得乳液的综合性能优良.

  17. Arresting relaxation in Pickering Emulsions

    Science.gov (United States)

    Atherton, Tim; Burke, Chris

    2015-03-01

    Pickering emulsions consist of droplets of one fluid dispersed in a host fluid and stabilized by colloidal particles absorbed at the fluid-fluid interface. Everyday materials such as crude oil and food products like salad dressing are examples of these materials. Particles can stabilize non spherical droplet shapes in these emulsions through the following sequence: first, an isolated droplet is deformed, e.g. by an electric field, increasing the surface area above the equilibrium value; additional particles are then adsorbed to the interface reducing the surface tension. The droplet is then allowed to relax toward a sphere. If more particles were adsorbed than can be accommodated by the surface area of the spherical ground state, relaxation of the droplet is arrested at some non-spherical shape. Because the energetic cost of removing adsorbed colloids exceeds the interfacial driving force, these configurations can remain stable over long timescales. In this presentation, we present a computational study of the ordering present in anisotropic droplets produced through the mechanism of arrested relaxation and discuss the interplay between the geometry of the droplet, the dynamical process that produced it, and the structure of the defects observed.

  18. Polymerization Using Phosphazene Bases

    KAUST Repository

    Zhao, Junpeng

    2015-09-01

    In the recent rise of metal-free polymerization techniques, organic phosphazene superbases have shown their remarkable strength as promoter/catalyst for the anionic polymerization of various types of monomers. Generally, the complexation of phosphazene base with the counterion (proton or lithium cation) significantly improves the nucleophilicity of the initiator/chain end resulting in highly enhanced polymerization rates, as compared with conventional metalbased initiating systems. In this chapter, the general features of phosphazenepromoted/catalyzed polymerizations and the applications in macromolecular engineering (synthesis of functionalized polymers, block copolymers, and macromolecular architectures) are discussed with challenges and perspectives being pointed out.

  19. Novel anhydrous emulsions: formulation as controlled release vehicles.

    Science.gov (United States)

    Suitthimeathegorn, Orawan; Jaitely, Vikas; Florence, Alexander T

    2005-07-25

    Novel anhydrous emulsions, which may offer some advantages as depot or reservoir vehicles for lipophilic drugs in controlled delivery systems, were formulated using castor oil as the disperse phase and dimethicone or cyclopentasiloxane as the continuous phase. Among the emulsifiers studied only silicone surfactants (cyclomethicone/dimethicone copolyols) which were miscible in silicone oil stabilized the emulsions. Cyclomethicone/PEG/PPG-18/18 Dimethicone and Cyclopentasiloxane/PEG/PPG-18/18 Dimethicone were more effective in lowering the interfacial tension between castor oil and both dimethicone and cyclopentasiloxane. Emulsions formulated using either of these two surfactants were found to be stable against phase separation and exhibited least globule growth over 168 h. The average particle size was found to be 2-6 microm in these systems formed by probe sonication. Slow release patterns of 3H-dehydroepiandrosterone (DHEA) and 3H-dexamethasone solubilized in the disperse castor oil phase into an aqueous dialyzing medium were observed over 48 h.

  20. Oxidative enzymatic gelation of sugar beet pectin for emulsion stabilization

    DEFF Research Database (Denmark)

    Abang Zaidel, Dayang Norulfairuz; Meyer, Anne S.

    2013-01-01

    emulsions has recently been investigated in model food emulsions. This paper reviews the pectin chemistry, enzymatic oxidative gelation mechanisms, interaction mechanisms of the sugar beet pectin with the emulsion droplets and explores how the gelation affects the rheology and stability of emulsion systems...

  1. Causes of formation and characteristics of water-fuel emulsions

    Directory of Open Access Journals (Sweden)

    П. Ф. Максютинський

    2000-09-01

    Full Text Available Considered are the causes of formation and characteristics of water-fuel emulsions in fuel tanks of aircrafts - dispersion and stability (time of water emulsion fallout Determined is distribution of emulsion water in fuel according to microdrops size caused by mechanical dispersion. It is shown that water-fuel emulsion formed by ultrasonic dispersion is similar to that formed by condensation

  2. The research about microscopic structure of emulsion membrane in O/W emulsion by NMR and its influence to emulsion stability.

    Science.gov (United States)

    Xie, Yiqiao; Chen, Jisheng; Zhang, Shu; Fan, Kaiyan; Chen, Gang; Zhuang, Zerong; Zeng, Mingying; Chen, De; Lu, Longgui; Yang, Linlin; Yang, Fan

    2016-03-16

    This paper discussed the influence of microstructure of emulsion membrane on O/W emulsion stability. O/W emulsions were emulsified with equal dosage of egg yolk lecithin and increasing dosage of co-emulsifier (oleic acid or HS15). The average particle size and centrifugal stability constant of emulsion, as well as interfacial tension between oil and water phase were determined. The microstructure of emulsion membrane had been studied by (1)H/(13)C NMR, meanwhile the emulsion droplets were visually presented with TEM and IFM. With increasing dosage of co-emulsifier, emulsions showed two stable states, under which the signal intensity of characteristic group (orient to lipophilic core) of egg yolk lecithin disappeared in NMR of emulsions, but that (orient to aqueous phase) of co-emulsifiers only had some reduction at the second stable state. At the two stable states, the emulsion membranes were neater in TEM and emulsion droplets were rounder in IFM. Furthermore, the average particle size of emulsions at the second stable state was bigger than that at the first stable state. Egg yolk lecithin and co-emulsifier respectively arranged into monolayer and bilayer emulsion membrane at the two stable states. The microstructure of emulsion membrane was related to the stability of emulsion. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Double Emulsion Droplets as Microreactors for Synthesis of Magnetic Macroporous Polymer Beads

    Institute of Scientific and Technical Information of China (English)

    Wei-cai Wang; Chao Peng; Kai Shi; Yan-xiong Pan; Hai-shan Zhang; Xiang-ling Ji

    2014-01-01

    An easy method is presented to fabricate monodisperse magnetic macroporous polymer beads (MMPBs).Waterin-oil high intemal phase emulsion (HIPE) is prepared by emulsifying aqueous iron ions solution in an oil phase containing monomers.The HIPE is introduced into a simple microfluidic device to fabricate monodisperse (water-in-oil)-in-water double emulsion droplets.The droplets serve as microreactors to synthesize Fe3O4 nanoparticles and are on-line polymerized to form MMPBs.The prepared MMPBs display uniform size,interconnected porous structure,superparamagnetic behavior and uniform distribution of Fe3O4 in polymer matrix.The MMPBs are characterized by scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FTIR),X-ray diffraction (XRD),transmission electron microscopy (TEM),vibrating sample magnetometry (VSM).We believe that this method is a universal technique in preparing macroporous nanocomposite beads.

  4. Stable emulsions prepared by self-assembly of hyaluronic acid and chitosan for papain loading.

    Science.gov (United States)

    Zhao, Donghua; Wei, Wei; Zhu, Ye; Sun, Jianhua; Hu, Qiong; Liu, Xiaoya

    2015-04-01

    A simple, green and effective process is developed to fabricate hyaluronic acid (HA)/chitosan (CS) complex colloidal particles through electrostatic interactions. The obtained complexes can be used as biocompatible emulsifiers and novel potential carriers for papain loading. An HA/CS mass ratio of 2 is the optimal condition leading to the smallest Dh (420.9 nm). The complexes with eight different mass ratios are used to stabilize white oil/water emulsions. The structure of the complexes at the oil-water interface varies in response to the mass ratio and can be classified into two typical structures, similar to typical polymeric surfactants and solid particulate emulsifiers. Furthermore, papain is introduced into the complex systems. Formation of the papain/HA/CS complexes in a compact form can protect the enzyme. Here, a novel strategy is introduced to fabricate a biocompatible emulsion from the HA/CS complexes and demonstrate that the stable complex is a suitable enzyme delivery system.

  5. Reconstitution of cortical actin networks within water-in-oil emulsions.

    Science.gov (United States)

    Abu Shah, Enas; Malik-Garbi, Maya; Keren, Kinneret

    2015-01-01

    We describe the reconstitution of dynamic cortical actin networks within cell-like compartments. The approach is based on encapsulation of Xenopus egg extract within water-in-oil emulsions. The growth of cortical actin networks is catalyzed by an amphiphilic actin nucleation-promoting factor that localizes to the water/oil interface. We first describe the preparation of cell-free Xenopus egg extract that provides all the soluble components of the actin machinery. We then describe the preparation of the amphiphilic, fluorescent actin nucleation-promoting factor that directs actin polymerization to the interface. Finally, we describe the steps required for assembly of dynamic actin cortices within water-in-oil emulsions, including the emulsification process and the sample preparation procedures. We provide recommendations for handling sensitive system components and discuss potential uses of this reconstitution approach for cytoskeletal research. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Characterizing emulsions by observation of single droplet collisions--attoliter electrochemical reactors.

    Science.gov (United States)

    Kim, Byung-Kwon; Boika, Aliaksei; Kim, Jiyeon; Dick, Jeffrey E; Bard, Allen J

    2014-04-02

    We report an electrochemical study of the collisions of single droplets in an emulsion by two methods. In the first method, an electroactive redox species, for example, ferrocene, inside a toluene-in-water emulsion droplet (but not in the continuous phase) is measured by chronoamperometry during a collision with an ultramicroelectrode (UME). Here, a blip or spike type of collision signal is observed, representing electrolysis of the droplet contents. In the second method, electrochemical oxidation of an electroactive redox species in the continuous aqueous phase is hindered by a droplet blocking collision. In this case, a staircase current decrease is observed. From an analysis of single soft particle collision data, one can find the emulsion droplet size distribution and the droplet contents.

  7. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

    oilcontaining formations or saline aquifers. The term globule refers to the water or liquid carbon dioxide droplets sheathed with ultrafine particles dispersed in the continuous external medium, liquid CO{sub 2} or H{sub 2}O, respectively. The key to obtaining very small globules is the shear force acting on the two intermixing fluids, and the use of ultrafine stabilizing particles or nanoparticles. We found that using Kenics-type static mixers with a shear rate in the range of 2700 to 9800 s{sup -1} and nanoparticles between 100-300 nm produced globule sizes in the 10 to 20 μm range. Particle stabilized emulsions with that kind of globule size should easily penetrate oil-bearing formations or saline aquifers where the pore and throat size can be on the order of 50 μm or larger. Subsequent research focused on creating particle stabilized emulsions that are deemed particularly suitable for Permanent Sequestration of Carbon Dioxide. Based on a survey of the literature an emulsion consisting of 70% by volume of water, 30% by volume of liquid or supercritical carbon dioxide, and 2% by weight of finely pulverized limestone (CaCO{sub 3}) was selected as the most promising agent for permanent sequestration of CO{sub 2}. In order to assure penetration of the emulsion into tight formations of sandstone or other silicate rocks and carbonate or dolomite rock, it is necessary to use an emulsion consisting of the smallest possible globule size. In previous reports we described a high shear static mixer that can create such small globules. In addition to the high shear mixer, it is also necessary that the emulsion stabilizing particles be in the submicron size, preferably in the range of 0.1 to 0.2 μm (100 to 200 nm) size. We found a commercial source of such pulverized limestone particles, in addition we purchased under this DOE Project a particle grinding apparatus that can provide particles in the desired size range. Additional work focused on attempts to generate particle stabilized

  8. Squalene and squalane emulsions as adjuvants.

    Science.gov (United States)

    Allison, A C

    1999-09-01

    Microfluidized squalene or squalane emulsions are efficient adjuvants, eliciting both humoral and cellular immune responses. Microfluidization stabilizes the emulsions and allows sterilization by terminal filtration. The emulsions are stable for years at ambient temperature and can be frozen. Antigens are added after emulsification so that conformational epitopes are not lost by denaturation and to facilitate manufacture. A Pluronic block copolymer can be added to the squalane or squalene emulsion. Soluble antigens administered in such emulsions generate cytotoxic T lymphocytes able to lyse target cells expressing the antigen in a genetically restricted fashion. Optionally a relatively nontoxic analog of muramyl dipeptide (MDP) or another immunomodulator can be added; however, the dose of MDP must be restricted to avoid systemic side effects in humans. Squalene or squalane emulsions without copolymers or MDP have very little toxicity and elicit potent antibody responses to several antigens in nonhuman primates. They could be used to improve a wide range of vaccines. Squalene or squalane emulsions have been administered in human cancer vaccines, with mild side effects and evidence of efficacy, in terms of both immune responses and antitumor activity.

  9. Downhole emulsion breaker injection into the lift gas stream

    Energy Technology Data Exchange (ETDEWEB)

    Lagerlef, D.L.; Sindelar, S.T.; McLelland, W.G.; Blumer, D.J.

    1995-12-31

    A program is in operation at Prudhoe Bay, Alaska which injects emulsion breaker downhole with lift gas to enhance production. This paper addresses the reasons emulsions can limit production in a gas lifted well and the benefits that can be realized by breaking the emulsion downhole. A discussion of the simple but effective produced fluids emulsion screening test and the field implementation of downhole emulsion breaker in wells at Prudhoe Bay are included in this paper.

  10. Making Polymeric Microspheres

    Science.gov (United States)

    Rhim, Won-Kyu; Hyson, Michael T.; Chung, Sang-Kun; Colvin, Michael S.; Chang, Manchium

    1989-01-01

    Combination of advanced techniques yields uniform particles for biomedical applications. Process combines ink-jet and irradiation/freeze-polymerization techniques to make polymeric microspheres of uniform size in diameters from 100 to 400 micrometer. Microspheres used in chromatography, cell sorting, cell labeling, and manufacture of pharmaceutical materials.

  11. Core-shell-structured silica/polyacrylate particles prepared by Pickering emulsion: influence of the nucleation model on particle interfacial organization and emulsion stability.

    Science.gov (United States)

    Ji, Jing; Shu, Shi; Wang, Feng; Li, Zhilin; Liu, Jingjun; Song, Ye; Jia, Yi

    2014-01-01

    This work reports a new evidence of the versatility of silica sol as a stabilizer for Pickering emulsions. The organization of silica particles at the oil-water interface is a function of the nucleation model. The present results show that nucleation model, together with monomer hydrophobicity, can be used as a trigger to modify the packing density of silica particles at the oil-water interface: Less hydrophobic methylmethacrylate, more wettable with silica particles, favors the formation of core-shell-structured composite when the composite particles are prepared by miniemulsion polymerization in which monomers are fed in batch (droplet nucleation). By contrast, hydrophobic butylacrylate promotes the encapsulating efficiency of silica when monomers are fed dropwise (homogeneous nucleation). The morphologies of polyacrylate-nano-SiO2 composites prepared from different feed ratio of methylmethacrylate/butylacrylate (with different hydrophobicity) and by different feed processes are characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. The results from SEM and TEM show that the morphologies of the as-prepared polyacrylate/nano-SiO2 composite can be a core-shell structure or a bare acrylic sphere. The stability of resulting emulsions composed of these composite particles is strongly dependent on the surface coverage of silica particles. The emulsion stability is improved by densely silica-packed composite particles.

  12. Applied bioactive polymeric materials

    CERN Document Server

    Carraher, Charles; Foster, Van

    1988-01-01

    The biological and biomedical applications of polymeric materials have increased greatly in the past few years. This book will detail some, but not all, of these recent developments. There would not be enough space in this book to cover, even lightly, all of the major advances that have occurred. Some earlier books and summaries are available by two of this book's Editors (Gebelein & Carraher) and these should be consul ted for additional information. The books are: "Bioactive Polymeric Systems" (Plenum, 1985); "Polymeric Materials In Medication" (Plenum, 1985); "Biological Acti vi ties of Polymers" (American Chemical Society, 1982). Of these three, "Bioacti ve Polymeric Systems" should be the most useful to a person who is new to this field because it only contains review articles written at an introductory level. The present book primarily consists of recent research results and applications, with only a few review or summary articles. Bioactive polymeric materials have existed from the creation of life...

  13. Use of olive oil-in-water gelled emulsions in model turkey breast emulsions

    Science.gov (United States)

    Serdaroğlu, M.; Öztürk, B.

    2017-09-01

    Today, gelled emulsion systems offer a novel possibility in lipid modification of meat products. In this study, we aimed to investigate the quality characteristics of model turkey emulsions that were prepared with olive oil-in-water gelled emulsion (GE) as partial or total beef fat replacer. The results indicated that while most of the GE treatments showed equivalent emulsion characteristics in terms of emulsion stability, water-holding capacity and cook yield, utilization of 100% GE as the lipid source could increase total expressible fluid of the model turkey emulsion and thus negatively affect the quality. Utilization of GE was effective in total fat reduction, as the model turkey emulsions formulated with more than 50% GE had significantly lower fat content compared to full-beef fat control model emulsion. However, beef fat replacement with GE produced considerable changes in colour parameters. Finally, it was concluded that utilization of GE as a partial beef fat replacer has good potential to enhance stability and reduce total fat in turkey meat emulsion products.

  14. Size determinations of colloidal fat emulsions

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Klaus, Katrin; Steiniger, Frank

    2009-01-01

    Size and size distributions of colloidal dispersions are of crucial importance for their performance and safety. In the present study, commercially available fat emulsions (Lipofundin N, Lipofundin MCT and Lipidem) were analyzed by photon correlation spectroscopy, laser diffraction with adequate...

  15. NEWS: Nuclear Emulsions for WIMP Search

    CERN Document Server

    Aleksandrov, A; Asada, T; Bender, D; Bodnarchuk, I; Buonaura, A; Buontempo, S; Chernyavskii, M; Chukanov, A; Consiglio, L; D'Ambrosio, N; De Lellis, G; De Serio, M; Di Crescenzo, A; Di Marco, N; Dmitrievski, S; Dzhatdoev, T; Fini, R A; Furuya, S; Galati, G; Gentile, V; Gorbunov, S; Gornushkin, Y; Guler, A M; Ichiki, H; Kamiscioglu, C; Kamiscioglu, M; Katsuragawa, T; Kimura, M; Konovalova, N; Kuge, K; Lauria, A; Loverre, P; Machii, S; Managadze, A; Monacelli, P; Montesi, M C; Naka, T; Nakamura, M; Nakano, T; Pastore, A; Podgrudkov, D; Polukhina, N; Pupilli, F; Roganova, T; Rosa, G; Sato, O; Shchedrina, T; Simone, S; Sirignano, C; Sotnikov, A; Starkov, N; Strolin, P; Tawara, Y; Tioukov, V; Umemoto, A; Vladymyrov, M; Yoshimoto, M; Zemskova, S

    2016-01-01

    Nowadays there is compelling evidence for the existence of dark matter in the Universe. A general consensus has been expressed on the need for a directional sensitive detector to confirm, with a complementary approach, the candidates found in conventional searches and to finally extend their sensitivity beyond the limit of neutrino-induced background. We propose here the use of a detector based on nuclear emulsions to measure the direction of WIMP-induced nuclear recoils. The production of nuclear emulsion films with nanometric grains is established. Several measurement campaigns have demonstrated the capability of detecting sub-micrometric tracks left by low energy ions in such emulsion films. Innovative analysis technologies with fully automated optical microscopes have made it possible to achieve the track reconstruction for path lengths down to one hundred nanometers and there are good prospects to further exceed this limit. The detector concept we propose foresees the use of a bulk of nuclear emulsion fi...

  16. Surfactant-enhanced cellulose nanocrystal Pickering emulsions.

    Science.gov (United States)

    Hu, Zhen; Ballinger, Sarah; Pelton, Robert; Cranston, Emily D

    2015-02-01

    The effect of surfactants on the properties of Pickering emulsions stabilized by cellulose nanocrystals (CNCs) was investigated. Electrophoretic mobility, interfacial tension, confocal microscopy and three-phase contact angle measurements were used to elucidate the interactions between anionic CNCs and cationic alkyl ammonium surfactants didecyldimethylammonium bromide (DMAB) and cetyltrimethylammonium bromide (CTAB). Both surfactants were found to adsorb onto CNCs with concentration-dependent morphology. At low concentrations, individual surfactant molecules adsorbed with alkyl tails pointing outward leading to hydrophobic CNCs. At higher concentrations, above the surfactant's apparent critical micelle concentration, surfactant aggregate morphologies on CNCs were inferred and the hydrophobicity of CNCs decreased. DMAB, which has two alkyl tails, rendered the CNCs more hydrophobic than CTAB which has only a single alkyl tail, at all surfactant concentrations. The change in CNC wettability from surfactant adsorption was directly linked to emulsion properties; adding surfactant increased the emulsion stability, decreased the droplet size, and controlled the internal phase of CNC Pickering emulsions. More specifically, a double transitional phase inversion, from oil-in-water to water-in-oil and back to oil-in-water, was observed for emulsions with CNCs and increasing amounts of DMAB (the more hydrophobic surfactant). With CNCs and CTAB, no phase inversion was induced. This work represents the first report of CNC Pickering emulsions with surfactants as well as the first CNC Pickering emulsions that can be phase inverted. The ability to surface modify CNCs in situ and tailor emulsions by adding surfactants may extend the potential of CNCs to new liquid formulations and extruded/spray-dried materials.

  17. Hexagonal phase based gel-emulsion (O/H1 gel-emulsion): formation and rheology.

    Science.gov (United States)

    Alam, Mohammad Mydul; Aramaki, Kenji

    2008-11-04

    The formation, stability, and rheological behavior of a hexagonal phase based gel-emulsion (O/H1 gel-emulsion) have been studied in water/C12EO8/hydrocarbon oil systems. A partial phase behavior study indicates that the oil nature has no effect on the phase sequences in the ternary phase diagram of water/C12EO8/oil systems but the domain size of the phases or the oil solubilization capacity considerably changes with oil nature. Excess oil is in equilibrium with the hexagonal phase (H1) in the ternary phase diagram in the H1+O region. The O/H1 gel-emulsion was prepared (formation) and kept at 25 degrees C to check stability. It has been found that the formation and stability of the O/H1 gel-emulsion depends on the oil nature. After 2 min observation (formation), the results show that short chain linear hydrocarbon oils (heptane, octane) are more apt to form a O/H1 gel-emulsion compared to long chain linear hydrocarbon oils (tetradecane, hexadecane), though the stability is not good enough in either system, that is, oil separates within 24 h. Nevertheless, the formation and stability of the O/H1 gel-emulsion is appreciably increased in squalane and liquid paraffin. It is surmised that the high transition temperature of the H1+O phase and the presence of a bicontinuous cubic phase (V1) might hamper the formation of a gel-emulsion. It has been pointed out that the solubilization of oil in the H1 phase could be related to emulsion stability. On the other hand, the oil nature has little or no effect on the formation and stability of a cubic phase based gel-emulsion (O/I1 gel-emulsion). From rheological measurements, it has found that the rheogram of the O/H1 gel-emulsion indicates gel-type structure and shows shear thinning behavior similar to the case of the O/I1 gel-emulsion. Rheological data infer that the O/I1 gel-emulsion is more viscous than the O/H1 gel-emulsion at room temperature but the O/H1 gel-emulsion shows consistency at elevated temperature.

  18. Reduction of Exhaust Smoke from Gas-Turbine Engines by Using Fuel Emulsions.

    Science.gov (United States)

    1980-10-21

    9.9.... 60 3A. __ .i ___ NAEC-92-114 LIST OF ILLUSTRATIONS (CONTINUED) Figure Title Page 66 Smoke Number Evaluacions for Experiments 11, 13, 14, and...pressure drop; examples of the resulting emulsions are il- lustrated in Figure 2. b. The homogenizer unit was integrated into the fuel system as an in

  19. The Synthesis of Amphiphilic Luminescent Graphene Quantum Dot and Its Application in Miniemulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Minxiang Zeng

    2016-01-01

    Full Text Available Although emulsion applications of microscale graphene sheets have attracted much attention recently, nanoscale graphene platelets, namely, graphene quantum dots (GQDs, have been rarely explored in interface science. In this work, we study the interfacial behaviors and emulsion phase diagrams of hydrophobic-functionalized graphene quantum dots (C18-GQDs. Distinctive from pristine graphene quantum dots (p-GQDs, C18-GQDs show several interesting surface-active properties including high emulsification efficiency in stabilizing dodecane-in-water emulsions. We then utilize the C18-GQDs as surfactants in miniemulsion polymerization of styrene, achieving uniform and relatively small polystyrene nanospheres. The high emulsification efficiency, low production cost, uniform morphology, intriguing photoluminescence, and extraordinary stability render C18-GQDs an attractive alternative in surfactant applications.

  20. Intravenous lipid emulsion in clinical toxicology

    Directory of Open Access Journals (Sweden)

    Oswald Sarah

    2010-10-01

    Full Text Available Abstract Intravenous lipid emulsion is an established, effective treatment for local anesthetic-induced cardiovascular collapse. The predominant theory for its mechanism of action is that by creating an expanded, intravascular lipid phase, equilibria are established that drive the offending drug from target tissues into the newly formed 'lipid sink'. Based on this hypothesis, lipid emulsion has been considered a candidate for generic reversal of toxicity caused by overdose of any lipophilic drug. Recent case reports of successful resuscitation suggest the efficacy of lipid emulsion infusion for treating non-local anesthetic overdoses across a wide spectrum of drugs: beta blockers, calcium channel blockers, parasiticides, herbicides and several varieties of psychotropic agents. Lipid emulsion therapy is gaining acceptance in emergency rooms and other critical care settings as a possible treatment for lipophilic drug toxicity. While protocols exist for administration of lipid emulsion in the setting of local anesthetic toxicity, no optimal regimen has been established for treatment of acute non-local anesthetic poisonings. Future studies will shape the evolving recommendations for lipid emulsion in the setting of non-local anesthetic drug overdose.

  1. Microemulsion systems applied to breakdown petroleum emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Neuma de Castro Dantas, Tereza; Avelino Dantas Neto, Afonso; Ferreira Moura, Everlane [Deptos de Quimica e Eng. Quimica, Universidade Federal do Rio Grande do Norte, Campus Universitario s/n, 59072.970, Natal/RN Campinas (Brazil)

    2001-12-29

    Microemulsion systems obtained using commercial surfactants with demulsifier and emulsion prevention properties have been employed to break down Brazilian crude water-in-oil (W/O) emulsions. These crude oils were supplied by the Brazilian oil company-PETROBRAS-and were characterized by the different Balance sheet of Sediment and Water (BSW) values of 48%, 36%, and 32%. The microemulsion systems formed in this study were composed of an aqueous phase (HCl 5.2% solution); an oil phase (toluene); a cosurfactant/surfactant (C/S) phase (isopropyl alcohol (C)/surfactants (S) with a ratio C/S of 9.0). The microemulsion efficiency to break down oil emulsions was evaluated by a direct contact method between the microemulsions and crude (W/O) emulsions. The Scheffe net statistical planning for mixtures was used to relate the component mass fractions to the relative breakdown of petroleum emulsions. The best composition of the microemulsion system for the complete breakdown of oil emulsions with high BSW values had the lowest C/S phase percentage.

  2. Conditions for equilibrium solid-stabilized emulsions.

    Science.gov (United States)

    Kraft, Daniela J; de Folter, Julius W J; Luigjes, Bob; Castillo, Sonja I R; Sacanna, Stefano; Philipse, Albert P; Kegel, Willem K

    2010-08-19

    Particular types of solid-stabilized emulsions can be thermodynamically stable as evidenced by their spontaneous formation and monodisperse droplet size, which only depends on system parameters. Here, we investigate the generality of these equilibrium solid-stabilized emulsions with respect to the basic constituents: aqueous phase with ions, oil, and stabilizing particles. From systematic variations of these constituents, we identify general conditions for the spontaneous formation of monodisperse solid-stabilized emulsions droplets. We conclude that emulsion stability is achieved by a combination of solid particles as well as amphiphilic ions adsorbed at the droplet surface, and low interfacial tensions of the bare oil-water interface of order 10 mN/m or below. Furthermore, preferential wetting of the colloidal particles by the oil phase is necessary for thermodynamic stability. We demonstrate the sufficiency of these basic requirements by extending the observed thermodynamic stability to emulsions of different compositions. Our findings point to a new class of colloid-stabilized meso-emulsions with a potentially high impact on industrial emulsification processes due to the associated large energy savings.

  3. Polysaccharide-based oleogels prepared with an emulsion-templated approach.

    Science.gov (United States)

    Patel, Ashok R; Cludts, Nick; Bin Sintang, Mohd Dona; Lewille, Benny; Lesaffer, Ans; Dewettinck, Koen

    2014-11-10

    The preparation and characterization of oleogels structured by using a combination of a surface-active and a non-surface-active polysaccharide through an emulsion-templated approach is reported. Specifically, the oleogels were prepared by first formulating a concentrated oil-in-water emulsion, stabilized with a combination of cellulose derivatives and xanthan gum, followed by the selective evaporation of the continuous water phase to drive the network formation, resulting in an oleogel with a unique microstructure and interesting rheological properties, including a high gel strength, G'>4000 Pa, shear sensitivity, good thixotropic recovery, and good thermostability.

  4. Crystallization in Emulsions: A Thermo-Optical Method to Determine Single Crystallization Events in Droplet Clusters

    Directory of Open Access Journals (Sweden)

    Serghei Abramov

    2016-08-01

    Full Text Available Delivery systems with a solid dispersed phase can be produced in a melt emulsification process. For this, dispersed particles are melted, disrupted, and crystallized in a liquid continuous phase (melt emulsification. Different to bulk crystallization, droplets in oil-in-water emulsions show individual crystallization behavior, which differs from droplet to droplet. Therefore, emulsion droplets may form liquid, amorphous, and crystalline structures during the crystallization process. The resulting particle size, shape, and physical state influence the application properties of these colloidal systems and have to be known in formulation research. To characterize crystallization behavior of single droplets in micro emulsions (range 1 µm to several hundred µm, a direct thermo-optical method was developed. It allows simultaneous determination of size, size distribution, and morphology of single droplets within droplet clusters. As it is also possible to differentiate between liquid, amorphous, and crystalline structures, we introduce a crystallization index, CIi, in dispersions with a crystalline dispersed phase. Application of the thermo-optical approach on hexadecane-in-water model emulsion showed the ability of the method to detect single crystallization events of droplets within emulsion clusters, providing detailed information about crystallization processes in dispersions.

  5. Influence of polysaccharides on the rheology and stabilization of α-pinene emulsions.

    Science.gov (United States)

    García, Ma Carmen; Alfaro, Ma Carmen; Calero, Nuria; Muñoz, José

    2014-05-25

    This work focuses on the need to include polysaccharides in a slightly concentrated O(α-pinene)/W emulsion, formulated with amphiphilic copolymers as emulsifiers. Rheology, laser diffraction and multiple light scattering were the main techniques used to assess the performance of gellan gum, xanthan gum and a mixture of both hydrocolloids as stabilizers. Small amplitude oscillatory shear results were consistent with the existence of three distinct microstructures and relaxation mechanisms, which depended on the hydrocolloid system used. The mechanical spectrum of the emulsion containing both polysaccharides signalled the occurrence of thermodynamic incompatibility between the two. Flow curves fitted to the Carreau-Yasuda model demonstrated a negative synergistic effect between gellan and xanthan gums. The droplet size distribution was similar for these systems, which highlighted the importance of the continuous phase for emulsion stability. Multiple light scattering illustrated that creaming was practically eliminated by the incorporation of polysaccharides, coalescence being the main destabilization mechanism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Preparation of Nano-porous Materials(Ⅰ) by Polymerization of Amphiphile Self-assemblies

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The polymerization of amphiphilic self-assemblies is a promising method to synthesize nano-structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self-assemblies to amphiphilic self-assemblies is given in this paper with 49 参考文献. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano-porous materials is briefly described.

  7. 含氟硅丙烯酸酯核壳乳液及涂膜表面性能%Synthesis of core-shell polyacrylate emulsion containing fluorine and silicon and surface properties of latex films

    Institute of Scientific and Technical Information of China (English)

    徐蕊; 肖新颜

    2009-01-01

    在可聚合阴离子乳化剂体系下,以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主要单体,甲基丙烯酸十二氟庚酯(DFMA)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)为功能单体,采用半连续种子乳液聚合法合成了含氟硅丙烯酸酯核壳乳液.考察了DFMA和KH-570用量对乳液聚合过程和乳胶膜表面疏水性能的影响,并对乳胶膜的表面自由能进行了估算.采用傅里叶红外光谱(FT-IR)、差示扫描量热仪(DSC)、热重(TG)、接触角(CA)及X射线光电子能谱(XPS)对氟硅丙乳液及乳胶膜进行了表征.研究结果表明,氟硅单体有效地参与了聚合,乳胶膜中氟硅元素呈梯度分布,当氟硅丙乳液中DFMA和KH-570用量分别为16%和5%(质量分数)时,涂膜-空气界面与去离子水的接触角为110.6°,涂膜的表面能低至15.4 mN· m~(-1),其疏水性和耐热性有较大幅度提高.%The core-shell polyacrylate emulsion containing fluorine and silicon in the shell was synthesized by semi-continuous seeded emulsion polymerization in the presence of reactive anionic emulsifier, using methyl methacrylate (MMA) and butyl acrylate (BA) as principal monomers, dodecafluoroheptyl methacrylate ( DFMA) and γ- ( methacryloxy) propyltrimethoxy silane ( KH-570 ) as functional monomers. The influences of the amount of fluorine and silicon monomers on emulsion polymerization process and surface hydrophobic properties of the latex films were discussed, and the surface free energies of prepared emulsion films were calculated. The fluorinated-silicated acrylate emulsion and their films were characterized by Fourier transform infrared spectrum (FT-IR), differential scanning calorimetry (DSC), thermogravimetry (TG), contact angle (CA) and X-ray photoelectron spectroscopy (XPS) analysis. The results showed that fluorine and silicon monomers had effectively copolymerized with acrylic monomers and a gradient distribution in the latex films was formed. The deioned

  8. Palm oil anionic surfactants based emulsion breaker (Case study of emulsions breaker at Semanggi Field production wells)

    Science.gov (United States)

    Muhpidah; Hambali, E.; Suryani, A.; Kartika, I. A.

    2017-05-01

    The presence of emulsion in oil production process is undesirable. The emulsion will increase the production costs, transportation and costs related to emulsion separation process between water and oil. The development of palm oil-based surfactant as an emulsion breaker needs to be conducted given the availability of abundant raw materials in Indonesia and as an alternative to petroleum-based surfactant. The purpose of this study is to produce palm oil-based emulsion breaker, assessing the effect of additive application to the emulsion breaker and analyze the performance of the emulsion breaker. This research was conducted by formulating palm oil anionic surfactant in water formation with the addition of co-surfactant additive and co-solvent. Palm oil anionic surfactant-based emulsion breaker with 0.5% concentration in water can reduce 50% of emulsions with the interfacial tension (IFT) of 2.33x10-2 dyne/cm. The addition of co-solvent (toluene: xylene) is able to remove the emulsion formed with a lower IFT namely 10-3 dyne / cm. The resulting emulsion breaker is capable to remove the emulsion between water and oil. The performance test of emulsion breaker show that the emulsion is able to maintain its performance at reservoir temperature with no indicate of plugging and the value generated incremental oil recovery values is 13%.

  9. Polymeric bicontinuous microemulsions

    DEFF Research Database (Denmark)

    Bates, F.S.; Maurer, W.W.; Lipic, P.M.

    1997-01-01

    High molecular weight block copolymers can be viewed as macromolecular surfactants when blended with thermodynamically incompatible homopolymers. This Letter describes the formation of polymeric bicontinuous microemulsions in nurtures containing a model diblock copolymer and two homopolymers...

  10. Stability of emulsion from bio-oil and diesel oil and combustion experimental study of emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Yaji, Huang; Zhaoping, Zhong; Baosheng, Jin; Bin, Li; Yu, Sun [Thermal Engineering Research Institute, Southeast University (China)

    2010-07-01

    This paper presents a study of the stability of an emulsion from bio-oil and diesel oil through an experimental combustion study. The emulsion was prepared using emulsifiers Span-80 and Tween-80 and bio-oil and diesel oil. This paper studies and analyses combustion, gaseous pollutants characteristics, and the effect of the HLB value and volume fraction of bio-oil on the stability of the emulsion. One of the major study conclusions was that the combustion temperature and the concentration of SO2, NOX and CO of emulsion are lower than those of diesel oil if equal flue gas oxygen is presumed. To conclude, emulsion could be used as an alternative oil fuel, however some questions such as: higher viscosity, higher exhaust heat loss, and very low acidity need more attention and more study in future research.

  11. STUDIES ON THE BLEND OF POLYACRYLATE EMULSIONS AND TACKIFIER RESIN EMULSIONS

    Institute of Scientific and Technical Information of China (English)

    HU Shuwen; YANG Yukun

    1996-01-01

    A series of polyacrylate emulsions were blended with tackifier resin emulsions such as modified rosin emulsion, C5 resin and C9 resin emulsion. The miscibility of the polyacrylates and tackifier resins was investigated by means of SEM and visual observation. The phase diagrams of the miscibility change systematically with the polarity of polyacrylates and tackifier resins. The influence of the content of the tackifier resins on the adhesion properties of the polyacrylate emulsions were also studied. The results show that the 180℃ peel strength is improved as the amount of the tackifier resin increases and comes to a maximum at a specific content. The ball tack property decreases slightly and the hold strength changes complicatedly as the tackifier resin increases.

  12. Influence of polymer-surfactant interactions on o/w emulsion properties and microcapsule formation.

    Science.gov (United States)

    Petrovic, Lidija B; Sovilj, Verica J; Katona, Jaroslav M; Milanovic, Jadranka L

    2010-02-15

    The aim of this work was to investigate the influence of interactions between 1.00%w/w hydroxypropylmethyl cellulose (HPMC) and the anionic surfactant sodium dodecylsulfate (SDS) on the properties of 20%w/w sunflower oil/water emulsion and the corresponding microcapsules obtained by spray drying technique. On the basis of the viscosity and rheological measurements, particle size and particle size distribution, and stability assessment, it was concluded that the emulsion characteristics depend strongly on the interaction mechanism. Significant increase in viscosity and non-Newtonian thixotropic behavior was observed in the SDS concentration range from 0.15 to 1.00%w/v, corresponding to HPMC-SDS interactions in the continuous phase. In the interaction region, a three-dimensional network is formed in the continuous phase by intermolecular binding of SDS molecules to the adjacent HPMC chains, which contributes to increase in the viscosity and thixotropic properties. The mean diameter of emulsion particles, d(vs), decreases with increase in SDS concentration, but emulsion stability depends on the adsorption layer structure, i.e. HPMC-SDS interactions. The HPMC/SDS complex adsorbed at the o/w interface makes the layer more compact, enhancing thus emulsion stability. Microcapsules, obtained in the form of powder by spray drying of emulsions, have good redispersibility in water, but their stability changes depending on the HPMC-SDS interaction mechanism, i.e., the HPMC/SDS complex forms a more compact layer that is resistant to breaking during the drying process. The highest encapsulation efficiency was found in the interaction region.

  13. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-01-22

    The present application offers a solution to the current problems associated with recovery and recycling of precious metals from scrap material, discard articles, and other items comprising one or more precious metals. The solution is premised on a microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  14. Galantamine-loaded PLGA nanoparticles, from nano-emulsion templating, as novel advanced drug delivery systems to treat neurodegenerative diseases

    Science.gov (United States)

    Fornaguera, C.; Feiner-Gracia, N.; Calderó, G.; García-Celma, M. J.; Solans, C.

    2015-07-01

    Polymeric nanoparticles could be promising drug delivery systems to treat neurodegenerative diseases. Among the various methods of nanoparticle preparation, nano-emulsion templating was used in the present study to prepare galantamine-loaded nano-emulsions by a low-energy emulsification method followed by solvent evaporation to obtain galantamine-loaded polymeric nanoparticles. This approach was found to be suitable because biocompatible, biodegradable and safe nanoparticles with appropriate features (hydrodynamic radii around 20 nm, negative surface charge and stability higher than 3 months) for their intravenous administration were obtained. Encapsulation efficiencies higher than 90 wt% were obtained with a sustained drug release profile as compared to that from aqueous and micellar solutions. The enzymatic activity of the drug was maintained at 80% after its encapsulation into nanoparticles that were non-cytotoxic at the required therapeutic concentration. Therefore, novel galantamine-loaded polymeric nanoparticles have been designed for the first time using the nano-emulsification approach and showed the appropriate features to become advanced drug delivery systems to treat neurodegenerative diseases.Polymeric nanoparticles could be promising drug delivery systems to treat neurodegenerative diseases. Among the various methods of nanoparticle preparation, nano-emulsion templating was used in the present study to prepare galantamine-loaded nano-emulsions by a low-energy emulsification method followed by solvent evaporation to obtain galantamine-loaded polymeric nanoparticles. This approach was found to be suitable because biocompatible, biodegradable and safe nanoparticles with appropriate features (hydrodynamic radii around 20 nm, negative surface charge and stability higher than 3 months) for their intravenous administration were obtained. Encapsulation efficiencies higher than 90 wt% were obtained with a sustained drug release profile as compared to that from

  15. The effect of butter grains on physical properties of butter-like emulsions.

    Science.gov (United States)

    Rønholt, Stine; Buldo, Patrizia; Mortensen, Kell; Andersen, Ulf; Knudsen, Jes C; Wiking, Lars

    2014-01-01

    Milk fat exists as globules in its natural state in milk. The potential of using globular fat to modulate the rheological properties and crystallization behavior in butter-like emulsions was studied in the present work. We conducted a comparative study of butter-like emulsions, with a fat phase consisting of 0, 10, 25, 50, or 100% anhydrous milk fat (AMF), the remaining fat being butter grains, and all samples containing 20% water, to obtain systematic variation in the ratio of globular fat. All emulsions were studied over 4wk of storage at 5°C. By combining small and large deformation rheology, we conducted a detailed characterization of the rheological behavior of butter-like emulsions. We applied differential scanning calorimetry to monitor thermal behavior, confocal laser scanning microscopy for microstructural analysis, and low-field pulsed nuclear magnetic resonance spectrometry to measure solid fat content. By combining these techniques, we determined that increasing the fraction of globular fat (by mixing with butter grains) decreases the hardness of butter-like emulsions up to an order of magnitude at d 1. However, no difference was observed in thermal behavior as a function of butter grain content, as all emulsions containing butter grains revealed 2 endothermal peaks corresponding to the high (32.7°C ± 0.6) and medium (14.6°C ± 0.1) melting fractions of fatty acids. In terms of microstructure, decreasing the amount of butter grains in the emulsions resulted in formation of a denser fat crystal network, corresponding to increased hardness. Moreover, microstructural analysis revealed that the presence of butter grains resulted in faster formation of a continuous fat crystal network compared with the 100% AMF sample, which was dominated by crystal clusters surrounded by liquid oil. During storage, hardness remained stable and no changes in thermal behavior were observed, despite an increase in solid fat content of up to 5%. After 28d of storage, we

  16. Fabrication, physicochemical characterization and preliminary efficacy evaluation of a W/O/W multiple emulsion loaded with 5% green tea extract

    Directory of Open Access Journals (Sweden)

    Tariq Mahmood

    2013-06-01

    Full Text Available Complex multiple emulsions have an excellent ability to fill large volumes of functional cosmetic agents. This study was aimed to encapsulate large volume of green tea in classical multiple emulsion and to compare its stability with a multiple emulsion without green tea extract. Multiple emulsions were developed using Cetyl dimethicone copolyol as lipophilic emulsifier and classic polysorbate-80 as hydrophilic emulsifier. Multiple emulsions were evaluated for various physicochemical aspects like conductivity, pH, microscopic analysis, rheology and these characteristics were followed for a period of 30 days in different storage conditions. In vitro and in vivo skin protection tests were also performed for both kinds of multiple emulsions i.e. with active (MeA and without active (MeB. Both formulations showed comparable characteristics regarding various physicochemical characteristics in different storage conditions. Rheological analysis showed that formulations showed pseudo plastic behavior upon continuous shear stress. Results of in vitro and in vivo skin protection data have revealed that the active formulation has comparable skin protection effects to that of control formulation. It was presumed that stable multiple emulsions could be a promising choice for topical application of green tea but multiple emulsions presented in this study need improvement in the formula, concluded on the basis of pH, conductivity and apparent viscosity data.

  17. In line monitoring of the preparation of water-in-oil-in-water (W/O/W) type multiple emulsions via dielectric spectroscopy.

    Science.gov (United States)

    Beer, Sebastian; Dobler, Dorota; Gross, Alexander; Ost, Martin; Elseberg, Christiane; Maeder, Ulf; Schmidts, Thomas Michael; Keusgen, Michael; Fiebich, Martin; Runkel, Frank

    2013-01-30

    Multiple emulsions offer various applications in a wide range of fields such as pharmaceutical, cosmetics and food technology. Two features are known to yield a great influence on multiple emulsion quality and utility as encapsulation efficiency and prolonged stability. To achieve a prolonged stability, the production of the emulsions has to be observed and controlled, preferably in line. In line measurements provide available parameters in a short time frame without the need for the sample to be removed from the process stream, thereby enabling continuous process control. In this study, information about the physical state of multiple emulsions obtained from dielectric spectroscopy (DS) is evaluated for this purpose. Results from dielectric measurements performed in line during the production cycle are compared to theoretically expected results and to well established off line measurements. Thus, a first step to include the production of multiple emulsions into the process analytical technology (PAT) guidelines of the Food and Drug Administration (FDA) is achieved. DS proved to be beneficial in determining the crucial stopping criterion, which is essential in the production of multiple emulsions. The stopping of the process at a less-than-ideal point can severely lower the encapsulation efficiency and the stability, thereby lowering the quality of the emulsion. DS is also expected to provide further information about the multiple emulsion like encapsulation efficiency.

  18. Water-in-Water Emulsion Based Synthesis of Hydrogel Nanospheres with Tunable Release Kinetics

    Science.gov (United States)

    Aydın, Derya; Kızılel, Seda

    2016-06-01

    Poly(ethylene glycol) (PEG) micro/nanospheres have several unique advantages as polymer based drug delivery systems (DDS) such as tunable size, large surface area to volume ratio, and colloidal stability. Emulsification is one of the widely used methods for facile synthesis of micro/nanospheres. Two-phase aqueous system based on polymer-polymer immiscibility is a novel approach for preparation of water-in-water (w/w) emulsions. This method is promising for the synthesis of PEG micro/nanospheres for biological systems, since the emulsion is aqueous and do not require organic solvents or surfactants. Here, we report the synthesis of nano-scale PEG hydrogel particles using w/w emulsions using phase separation of dextran and PEG prepolymer. Dynamic light scattering (DLS) and scaning electron microscopy (SEM) results demonstrated that nano-scale hydrogel spheres could be obtained with this approach. We investigated the release kinetics of a model drug, pregabalin (PGB) from PEG nanospheres and demonstrated the influence of polymerization conditions on loading and release of the drug as well as the morphology and size distribution of PEG nanospheres. The experimental drug release data was fitted to a stretched exponential function which suggested high correlation with experimental results to predict half-time and drug release rates from the model equation. The biocompatibility of nanospheres on human dermal fibroblasts using cell-survival assay suggested that PEG nanospheres with altered concentrations are non-toxic, and can be considered for controlled drug/molecule delivery.

  19. Preparation, physical property and thermal physical property of phase change microcapsule slurry and phase change emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China); Xu, Hui; Zhang, Yingping [School of Architecture, Tsinghua University, Beijing 100084 (China)

    2003-12-01

    Phase change microcapsule slurry and phase change emulsion are two novel two-phase heat transfer fluids. Compared with a conventional single-phase heat transfer fluid such as water, their apparent specific heats in the phase change temperature range are greatly increased. Due to this, the heat transfer ability and energy transport ability can be obviously improved. Therefore, they have many potentially important applications in fields such as heating, ventilating, air-conditioning, refrigeration and heat exchangers. In this paper, a phase change emulsion was prepared by mixing film synthesis, and a phase change microcapsule slurry was prepared by in situ polymerization with polystyrene, polymethyl methacrylate, polyethyl methacrylate as encapsulation material, respectively. Physical properties, such as viscosity, diameter and its distribution of microcapsule and emulsion were investigated. The relationship between the concentration of tetradecane and physical properties have been discussed in detail. Meanwhile, the thermal physical properties of these two fluids were determined by DSC. Also, the influence of tetradecane concentration on phase change temperature and phase change heat has been discussed.

  20. Preparation, physical property and thermal physical property of phase change microcapsule slurry and phase change emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Rui Yang [Tsinghua Univ., Dept. of Chemical Engineering, Beijing (China); Hui Xu; Yingping Zhang [Tsinghua Univ., School of Architecture, Beijing (China)

    2003-12-01

    Phase change microcapsule slurry and phase change emulsion are two novel two-phase heat transfer fluids. Compared with a conventional single-phase heat transfer fluid such as water, their apparent specific heats in the phase change temperature range are greatly increased. Due to this, the heat transfer ability and energy transport ability can be obviously improved. Therefore, they have many potentially important applications in fields such as heating, ventilating, air-conditioning, refrigeration and heat exchangers. In this paper, a phase change emulsion was prepared by mixing film synthesis, and a phase change microcapsule slurry was prepared by in situ polymerization with polystyrene, polymethyl methacrylate, polyethyl methacrylate as encapsulation material, respectively. Physical properties, such as viscosity, diameter and its distribution of microcapsule and emulsion were investigated. The relationship between the concentration of tetradecane and physical properties have been discussed in detail. Meanwhile, the thermal physical properties of these two fluids were determined by DSC. Also, the influence of tetradecane concentration on phase change temperature and phase change heat has been discussed. (Author)

  1. FORMULATION OF CLINDAMYCIN NANO-EMULSION

    Directory of Open Access Journals (Sweden)

    K. Jiyauddin *, A. Fadli , J. C. Wei , A. Jawad , A. D. Samer , M. Kaleemullah, S. Budiasih, S. Rasha , M. R. Rasny , Y. K. Sung , A. H. Junainah , H. Todo and Y. Eddy

    2015-05-01

    Full Text Available Nano-emulsions consist of fine oil-in-water or water-in-oil dispersions, having droplets covering the size range of 10 - 600 nm. The aim of this study is to formulate nano-emulsion of Clindamycin by using Emulsion Phase Inversion method and olive oil as the oil phase. Pseudo ternary phase diagram was first developed by using distilled water, olive oil and mixture of surfactants (Tween®80 and Span®20 at a ratio of 1:1. Then, appearance test and microscopic examination were done for all the pre-formulation. Three potential pre-formulation were then selected and incorporated with the Clindamycin Phosphate and Methyl Paraben. The mean droplet size and stability studies were done for these three formulations. Clindamycin Nano-emulsions were not obtained using the Emulsion Phase Inversion (EPI method in this study, whereby the mean droplet sizes were in micro-range. However, out of all the three formulations which undergone extensive studies which include the heating-cooling cycle, whereby the formulation F8 and F17 were found to be physically stable. Significant differences were identified on the pH value and viscosity measurement for all the three formulations which undergone the heating-cooling cycle; except for the pH in F17. Furthermore, the formulation F8 had the smallest droplet size of 0.92 µm. Future research on this topic is needed to reduce the droplet size of the formulation.

  2. Tuneable Rheological Properties of Fluorinated Pickering Emulsions

    Science.gov (United States)

    Chacon Orellana, Laura Andreina; Riechers, Birte; Caen, Ouriel; Baret, Jean-Christophe

    Pickering emulsions are an appealing approach to stabilize liquid-liquid dispersions without surfactants. Recently, amphiphilic silica nanoparticles have been proposed as an alternative to surfactants for droplet microfluidics applications, where aqueous drops are stabilized in fluorinated oils. This system, proved to be effective in preventing the leakage of resorufin, a model dye that was known to leak in surfactant-stabilized drops. The overall capabilities of droplet-based microfluidics technology is highly dependent on the dynamic properties of droplets, interfaces and emulsions. Therefore, fluorinated pickering emulsions dynamic properties need to be characterized, understood and controlled to be used as a substitute of already broadly studied emulsions for droplet microfluidics applications. In this study, fluorinated pickering emulsions have been found to behave as a Herschel Bulkley fluid, representing a challenge for common microfluidic operations as re-injection and sorting of droplets. We found that this behavior is controlled by the interaction between the interfacial properties of the particle-laden interface and the bulk properties of the two phases

  3. High pressure-resistant nonincendive emulsion explosive

    Science.gov (United States)

    Ruhe, Thomas C.; Rao, Pilaka P.

    1994-01-01

    An improved emulsion explosive composition including hollow microspheres/bulking agents having high density and high strength. The hollow microspheres/bulking agents have true particle densities of about 0.2 grams per cubic centimeter or greater and include glass, siliceous, ceramic and synthetic resin microspheres, expanded minerals, and mixtures thereof. The preferred weight percentage of hollow microspheres/bulking agents in the composition ranges from 3.0 to 10.0 A chlorinated paraffin oil, also present in the improved emulsion explosive composition, imparts a higher film strength to the oil phase in the emulsion. The emulsion is rendered nonincendive by the production of sodium chloride in situ via the decomposition of sodium nitrate, a chlorinated paraffin oil, and sodium perchlorate. The air-gap sensitivity is improved by the in situ formation of monomethylamine perchlorate from dissolved monomethylamine nitrate and sodium perchlorate. The emulsion explosive composition can withstand static pressures to 139 bars and dynamic pressure loads on the order of 567 bars.

  4. [Effect of emulsion on chromatographic process].

    Science.gov (United States)

    Jiang, Yulei; Li, Xi

    2004-11-01

    The types and features of concentration wave of the chromatographic process in which the mobile phase was emulsion were studied theoretically by the method of characteristics and the concept of multi mobile phase chromatography. When the mobile phase is an emulsion, solute is partitioned between the inner and outer phases of the emulsion as well as simultaneously adsorbed on the stationary phase resulting in the great difference of concentration profiles from the case in which the mobile phase is homogenous. The various profiles and mechanisms of concentration wave of the chromatographic process in which the partition relationship between the inner and outer phases of the emulsion and the adsorption isotherm on the stationary phase were both Langmuir-like were analyzed and discussed with corresponding examples, and the comparison with the case in which the mobile phase is homogenous is also done. It is shown that the chromatographic progress with emulsion is more complicated and multiple. The existence of multi mobile phases may sharpen simple wave to be shock wave or diffuse shock wave to be simple wave.

  5. Preparation of Conductive PANI/PVA Composites via an Emulsion Route

    Directory of Open Access Journals (Sweden)

    Xiang-Qin Wang

    2013-01-01

    Full Text Available A facile and novel strategy for preparing polyaniline/polyvinyl alcohol (PANI/PVA composite emulsion is reported wherein the reaction is carried out via the emulsion polymerization using ammonium peroxydisulfate (APS as the oxidizing agent and dodecylbenzene sulfonic acid (DBSA as the protonic acid. The PANI/PVA composite membranes have been characterized using optical microscope, scanning electron microscope (SEM, thermogravimetric analysis (TGA, Fourier transform infrared spectroscopy (FTIR, and electrochemical workstation. It is interesting that the electrical conductivity of the PANI/PVA composites is estimated to be as high as 1.28 S/cm. The experimental results show that the surface of PANI/PVA composite membranes exhibits good integrity. The PANI particles at the nanoscale are dispersed in the PVA matrix, and the electrochromic behaviors of PANI/PVA composites obtained at different polymerization temperatures can be compared based on cyclic voltammetry (CV curves, revealing that PANI/PVA composites synthesized at room temperature are better than those synthesized at low temperature.

  6. PHEA-PLA biocompatible nanoparticles by technique of solvent evaporation from multiple emulsions.

    Science.gov (United States)

    Cavallaro, Gennara; Craparo, Emanuela Fabiola; Sardo, Carla; Lamberti, Gaetano; Barba, Anna Angela; Dalmoro, Annalisa

    2015-11-30

    Nanocarriers of amphiphilic polymeric materials represent versatile delivery systems for poorly water soluble drugs. In this work the technique of solvent evaporation from multiple emulsions was applied to produce nanovectors based on new amphiphilic copolymer, the α,β-poly(N-2-hydroxyethyl)-DL-aspartamide-polylactic acid (PHEA-PLA), purposely synthesized to be used in the controlled release of active molecules poorly soluble in water. To this aim an amphiphilic derivative of PHEA, a hydrophilic polymer, was synthesized by derivatization of the polymeric backbone with hydrophobic grafts of polylactic acid (PLA). The achieved copolymer was thus used to produce nanoparticles loaded with α tocopherol (vitamin E) adopted as lipophilic model molecule. Applying a protocol based on solvent evaporation from multiple emulsions assisted by ultrasonic energy and optimizing the emulsification process (solvent selection/separation stages), PHEA-PLA nanostructured particles with total α tocopherol entrapment efficiency (100%), were obtained. The drug release is expected to take place in lower times with respect to PLA due to the presence of the hydrophilic PHEA, therefore the produced nanoparticles can be used for semi-long term release drug delivery systems.

  7. Factors governing partial coalescence in oil-in-water emulsions.

    Science.gov (United States)

    Fredrick, Eveline; Walstra, Pieter; Dewettinck, Koen

    2010-01-15

    The consequences of the instability mechanism partial coalescence in oil-in-water food emulsions show a discrepancy. On the one hand, it needs to be avoided in order to achieve an extended shelf life in food products like sauces, creams and several milk products. On the other hand, during the manufacturing of products like ice cream, butter and whipped toppings partial coalescence is required to achieve the desired product properties. It contributes to the structure formation, the physicochemical properties (stability, firmness,...) and the sensory perception, like fattiness and creaminess of the final food products. This review critically summarises the findings of partial coalescence in oil-in-water emulsions in order to provide insight in how to enhance and retard it. Next to the pioneering work, a large set of experimental results of more recent work is discussed. First, the general mechanism of partial coalescence is considered and a distinction is made between partial and 'true' coalescence. The main differences are: the required solid particles in the dispersed oil phase, the formation of irregular clusters and the increased aggregation rate. Second, the kinetics of partial coalescence is discussed. In more detail, potential parameters affecting the rate of partial coalescence are considered by means of the encounter frequency and capture efficiency of the fat globules. The flow conditions, the fat volume fraction and the physicochemical properties of continuous aqueous phase affect both the encounter frequency and capture efficiency while the actual temperature, temperature history and the composition and formulation of the emulsion mainly affect the capture efficiency.

  8. Tuning Amphiphilicity of Particles for Controllable Pickering Emulsion

    OpenAIRE

    Zhen Wang; Yapei Wang

    2016-01-01

    Pickering emulsions with the use of particles as emulsifiers have been extensively used in scientific research and industrial production due to their edge in biocompatibility and stability compared with traditional emulsions. The control over Pickering emulsion stability and type plays a significant role in these applications. Among the present methods to build controllable Pickering emulsions, tuning the amphiphilicity of particles is comparatively effective and has attracted enormous attent...

  9. Lignocellulose Nanofiber-Reinforced Polystyrene Produced from Composite Microspheres Obtained in Suspension Polymerization Shows Superior Mechanical Performance.

    Science.gov (United States)

    Ballner, Daniel; Herzele, Sabine; Keckes, Jozef; Edler, Matthias; Griesser, Thomas; Saake, Bodo; Liebner, Falk; Potthast, Antje; Paulik, Christian; Gindl-Altmutter, Wolfgang

    2016-06-01

    A facile approach to obtaining cellulose nanofiber-reinforced polystyrene with greatly improved mechanical performance compared to unreinforced polystyrene is presented. Cellulose nanofibers were obtained by mechanical fibrillation of partially delignified wood (MFLC) and compared to nanofibers obtained from bleached pulp. Residual hemicellulose and lignin imparted amphiphilic surface chemical character to MFLC, which enabled the stabilization of emulsions of styrene in water. Upon suspension polymerization of styrene from the emulsion, polystyrene microspheres coated in MFLC were obtained. When processed into polymer sheets by hot-pressing, improved bending strength and superior impact toughness was observed for the polystyrene-MFLC composite compared to the un-reinforced polystyrene.

  10. Detection of low energy antimatter with emulsions

    CERN Document Server

    Aghion, S; Ariga, T; Bollani, M; Cas, E Dei; Ereditato, A; Evans, C; Ferragut, R; Giammarchi, M; Pistillo, C; Romé, M; Sala, S; Scampoli, P

    2016-01-01

    Emulsion detectors feature a very high position resolution and consequently represent an ideal device when particle detection is required at the micrometric scale. This is the case of quantum interferometry studies with antimatter, where micrometric fringes have to be measured. In this framework, we designed and realized a new emulsion based detector characterized by a gel enriched in terms of silver bromide crystal contents poured on a glass plate. We tested the sensitivity of such a detector to low energy positrons in the range 10-20 keV. The obtained results prove that nuclear emulsions are highly efficient at detecting positrons at these energies. This achievement paves the way to perform matter-wave interferometry with positrons using this technology.

  11. Multi-body coalescence in Pickering emulsions

    Science.gov (United States)

    Wu, Tong; Wang, Haitao; Jing, Benxin; Liu, Fang; Burns, Peter C.; Na, Chongzheng

    2015-01-01

    Particle-stabilized Pickering emulsions have shown unusual behaviours such as the formation of non-spherical droplets and the sudden halt of coalescence between individual droplets. Here we report another unusual behaviour of Pickering emulsions—the simultaneous coalescence of multiple droplets in a single event. Using latex particles, silica particles and carbon nanotubes as model stabilizers, we show that multi-body coalescence can occur in both water-in-oil and oil-in-water emulsions. The number of droplets involved in the nth coalscence event equals four times the corresponding number of the tetrahedral sequence in close packing. Furthermore, coalescence is promoted by repulsive latex and silica particles but inhibited by attractive carbon nanotubes. The revelation of multi-body coalescence is expected to help better understand Pickering emulsions in natural systems and improve their designs in engineering applications.

  12. Optical diffusers based on silicone emulsions

    Science.gov (United States)

    Wang, Jui-Hao; Lien, Shui-Yang; Ho, Jeng-Rong; Shih, Teng-Kai; Chen, Chia-Fu; Chen, Chien-Chung; Whang, Wha-Tzong

    2009-12-01

    The present study provides an experimental approach for fabricating optical diffuser films based on silicone emulsions. The silicone emulsion consisting of silicone polymer (Sylgard 184) and NaCl aq. solution was used as the optical material of diffusers, wherein NaCl aq. solution was severed as surfactant to stabilize the emulsions. After stirring mechanically, microscaled water drop with various sizes distributed randomly in silicone polymer, wherein water drop was used as scattering diffusion particles. To modulate the volume of NaCl aq. solution, the diffusing performance of diffusers could be change by different amount drop particles. Thereafter, an optical examination was carried out to characterize optical properties, transmittance, and light diffusivity of volumetric diffuser films.

  13. Forces acting in quasi 2d emulsions

    Science.gov (United States)

    Orellana, Carlos; Lowensohn, Janna; Weeks, Eric

    We study the forces in a quasi two dimensional emulsion system. Our samples are oil-in-water emulsions confined between two close-spaced parallel plates, so that the oil droplets are deformed into pancake shapes. By means of microscopy, we measure the droplet positions and their deformation, which we can relate to the contact forces due to surface tension. We improve over prior work in our lab, achieving a better force resolution. We use this result to measure and calibrate the viscous forces acting in our system, which fully determine all the forces on the droplets. Our results can be applied to study static configurations of emulsion, as well as faster flows.

  14. Storage stability of marine phospholipids emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline Pascale

    Marine phospholipids (MPL) are believed to provide more advantages than fish oil from the same source. They are considered to have a better bioavailability, a better resistance towards oxidation and a higher content of polyunsaturated fatty acids such as eicosapentaenoic (EPA) and docosahexaenoic...... of secondary volatile compounds by Solid Phase Microextraction at several time intervals at 2°C storage. Preliminary results showed that marine phospholipids emulsion has a good oxidative stability....... acids (DHA) than oily triglycerides (fish oil). Therefore, the objective of this study is to explore the feasibility of using marine phospholipids emulsions as delivery system through investigation of the physical, oxidative and hydrolytic stability of MPL emulsions with or without addition of fish oil...

  15. [Nasal submicron emulsion of Scutellariae Radix extract preparation technology research based on phase transfer of solute technology].

    Science.gov (United States)

    Shi, Ya-jun; Shi, Jun-hui; Chen, Shi-bin; Yang, Ming

    2015-07-01

    Based on the demand of nasal drug delivery high drug loadings, using the unique phase transfer of solute, integrating the phospholipid complex preparation and submicron emulsion molding process of Scutellariae Radix extract, the study obtained the preparation of the high drug loadings submicron emulsion of Scutellariae Radix extract. In the study of drug solution dispersion method, the uniformity of drug dispersed as the evaluation index, the traditional mixing method, grinding, homogenate and solute phase transfer technology were investigated, and the solute phase transfer technology was adopted in the last. With the adoption of new technology, the drug loading capacity reached 1.33% (phospholipid complex was 4%). The drug loading capacity was improved significantly. The transfer of solute method and timing were studied as follows,join the oil phase when the volume of phospholipid complex anhydrous ethanol solution remaining 30%, the solute phase transfer was completed with the continued recycling of anhydrous ethanol. After drug dissolved away to oil phase, the preparation technology of colostrum was determined with the evaluation index of emulsion droplet form. The particle size of submicron emulsion, PDI and stability parameters were used as evaluation index, orthogonal methodology were adopted to optimize the submicron emulsion ingredient and main influential factors of high pressure homogenization technology. The optimized preparation technology of Scutellariae Radix extract nasal submicron emulsion is practical and stable.

  16. The role of electrostatics in saliva-induced emulsion flocculation

    NARCIS (Netherlands)

    Silletti, Erika; Vingerhoeds, Monique H.; Norde, Willem; Van Aken, George A.

    Upon consumption food emulsions undergo different processes, including mixing with saliva. It has been shown that whole saliva induces emulsion flocculation [van Aken, G. A., Vingerhoeds, M. H., & de Hoog, E. H. A. (2005). Colloidal behaviour of food emulsions under oral conditions. In E. Dickinson

  17. The role of electrostatistics in saliva-induced emulsion flocculation

    NARCIS (Netherlands)

    Silletti, E.; Vingerhoeds, M.H.; Norde, W.; Aken, van G.A.

    2007-01-01

    Upon consumption food emulsions undergo different processes, including mixing with saliva. It has been shown that whole saliva induces emulsion flocculation [van Aken, G. A., Vingerhoeds, M. H., & de Hoog, E. H. A. (2005). Colloidal behaviour of food emulsions under oral conditions. In E.

  18. Formula for emulsifier for production of emulsion fuels

    Energy Technology Data Exchange (ETDEWEB)

    Simakawa, K.; Arai, T.; Oseki, O.; Tega, K.; Wakidzaka, A.

    1982-05-20

    Patent for an emulsifier for preparation of emulsion fuels type v/m (formula provided). This particular formula is utilized to derive emulsion fuels from kerosene, light and heavy oils, etc. The emulsions have water drops of even size and a high thermal stability. When these fuels are used, formation of soot and nitrogen oxides is reduced.

  19. Physico-chemical Properties of Marine Phospholipid Emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.

    2012-01-01

    and the stability of their emulsions. Physical stability was investigated through particle size distribution (PSD), zeta potential, microscopy inspection and emulsion separation (ES); while the oxidative and hydrolytic stability of emulsions were investigated through peroxide value (PV) and free fatty acids value...

  20. The role of electrostatics in saliva-induced emulsion flocculation

    NARCIS (Netherlands)

    Silletti, Erika; Vingerhoeds, Monique H.; Norde, Willem; Van Aken, George A.

    2007-01-01

    Upon consumption food emulsions undergo different processes, including mixing with saliva. It has been shown that whole saliva induces emulsion flocculation [van Aken, G. A., Vingerhoeds, M. H., & de Hoog, E. H. A. (2005). Colloidal behaviour of food emulsions under oral conditions. In E. Dickinson

  1. The role of electrostatistics in saliva-induced emulsion flocculation

    NARCIS (Netherlands)

    Silletti, E.; Vingerhoeds, M.H.; Norde, W.; Aken, van G.A.

    2007-01-01

    Upon consumption food emulsions undergo different processes, including mixing with saliva. It has been shown that whole saliva induces emulsion flocculation [van Aken, G. A., Vingerhoeds, M. H., & de Hoog, E. H. A. (2005). Colloidal behaviour of food emulsions under oral conditions. In E. Dickin

  2. SEED SEMICONTINUOUS EMULSION MULTI-COPOLYMERIZATION OF (METH)ACRYLATES WITH HIGH-SOLID CONTENT:EFFECT OF THE OPERATION CONDITIONS

    Institute of Scientific and Technical Information of China (English)

    WANG Wenjun; YU Zaizhang; LI Bogeng; PAN Zuren

    1995-01-01

    The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA),2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate(HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solidcontent. The effects of monomer emulsion feed rates (Ra) and (R/E)E values, the ratio ofemulsifier amount between the initial charge (R) and the addition monomer emulsion (E) ,on the polymerization reaction features, the viscosities, surface tensions,particle sizes andparticle sizes distributions of latexes,Tg and the insoluble fractions of films, the 180° peelstrength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, preparedfrom the latexes, were studied. Experimental study shows that the grafting and cross-linking fraction in the PSA tapes must be controlled within a suitable range to keep thebalance of the 180° peel strength, tack and holding power.

  3. Synthesis and Characterization of nano-SiO2 modified fluorine-containing polyacrylate emulsifier-free emulsion

    Science.gov (United States)

    Zhou, Jianhua; Chen, Xin; Duan, Hao; Ma, Jianzhong; Ma, Yurong

    2015-03-01

    Nano-SiO2 modified fluorine-containing polyacrylate emulsifier-free emulsion, consisting of methyl methacrylate, butyl acrylate, dodecafluoroheptyl methacrylate and ethyl silicate, was successfully synthesized by emulsion polymerization using surfmer and sol-gel process. When increasing ethyl silicate content, the latex centrifugal stability decreased, and the latex particle size increased. The contact angle results showed that the finished fabric had an excellent water and oil repellency. Furthermore, compared with fluorine-containing polyacrylate emulsifier-free emulsion, the obtained nano-SiO2 modified fluorine-containing polyacrylate emulsifier-free emulsion proved to be highly solvent-resistant and water-resistant. In addition, the transmission electron microscopy (TEM) indicated that the nano-SiO2 presented on the surface of latex particles. The atomic force microscope (AFM) and energy dispersive X-ray spectrometer (EDX) confirmed that the hybrid film had a rough surface and the organic fluorine segment could migrate onto the film-air interface.

  4. Size determinations of colloidal fat emulsions

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Klaus, Katrin; Steiniger, Frank

    2009-01-01

    Size and size distributions of colloidal dispersions are of crucial importance for their performance and safety. In the present study, commercially available fat emulsions (Lipofundin N, Lipofundin MCT and Lipidem) were analyzed by photon correlation spectroscopy, laser diffraction with adequate...... but a slightly smaller size was indicated by all methods for Lipidem. Sub-micron resolution was best in the Coulter LS but the fraction of larger particles in the upper nm-range was presumably underestimated. The emulsions could be analyzed in a highly reproducible manner by asymmetrical flow field...

  5. Treatment of cocaine overdose with lipid emulsion.

    Science.gov (United States)

    Jakkala-Saibaba, R; Morgan, P G; Morton, G L

    2011-12-01

    We describe the management and recovery of a 28-year-old man following a history of overdose by nasal inhalation of cocaine. The patient was presented in a comatose state suffering from seizures and marked cardiovascularly instability. Intravenous lipid emulsion was administered following initial resuscitation and tracheal intubation, as a means of treating persistent cardiac arrhythmias and profound hypotension. Following lipid emulsion therapy, the patient's life-threatening cardiovascular parameters rapidly improved and he recovered well without any side effects, thus being discharged within 2 days. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

  6. Plasma polymerization by Softplasma

    DEFF Research Database (Denmark)

    Jiang, J.; Wu, Zhenning; Benter, Maike

    2008-01-01

    In the late 19th century, the first depositions - known today as plasma polymers, were reported. In the last century, more and more research has been put into plasma polymers. Many different deposition systems have been developed. [1, 2] Shi F. F. broadly classified them into internal electrode......, external electrode, and electrodeless microwave or high frequency reactors. [3] Softplasma™ is an internal electrode plasma setup powered by low frequenc~ gower supply. It was developed in late 90s for surface treatment of silicone rubber. [ ]- 5] It is a low pressure, low electron density, 3D homogenous...... plasma. In this study, we are presenting the surface modification"pf polymers by plasma polymerization using Softplasma™. Softplasma™ can be used for two major types of polymerization: polymerization of vinyl monomers, where plasma acts as initiator; chemical vapour deposition, where plasma acts...

  7. Synthesis and Characterization of Fluorine-containing polyacrylate emulsion with Core-Shell Structure%核-壳结构含氟丙烯酸酯乳液的全盛与表征

    Institute of Scientific and Technical Information of China (English)

    肖新颜; 刘健飞

    2008-01-01

    A fluorine-containing polyacrylate copolymer emulsion was synthesized by a seed emulsion polymerization method.in which methyl methacrylate(MMA)and butyl acrylate(BA)were USed as main monomers and hexafluorobutyl methacrylate(HFMA)as fluorine-containing monomer.The structure and properties were characterized by Fourier transform infrared spectrum(FT-IR),transmission electron microscopy(TEM),particle size analysis,X-ray photoelectron spectroscopy(XPS),contact angle(CA),differential scanning calorimetry(DSC)and thermogravimetry (TG) analysis.The FTIR and TEM results showed that HFMA Was effectively involved in the emulsion copolvmerization.and the formed emulsion particles had a core-shell structure and a narrow particle size distribution.XPS and CA analysis revealed that a gradient concentration of fluofine existed in the depth profile of fluorine-containing emulsion film which was richer in fluorine and more hydrophobic in one side.DSC and TG analysis also showed that a clear core-shell structure existed in the fluorine-containing emulsion particles,and their film showed higherthermal stability than that of fluorine-ree emulsion.

  8. Hydroplasticization of polymers: model predictions and application to emulsion polymers.

    Science.gov (United States)

    Tsavalas, John G; Sundberg, Donald C

    2010-05-18

    The plasticization of a polymer by solvent has a dramatic impact on both its thermal and mechanical behavior. With increasing demand for zero volatile organic compound materials and coatings, water is often the sole solvent used both in the polymer synthesis and in formulation and application; latex colloids derived from emulsion polymerization are a good example. The impact of water on the glass transition temperature of a polymer thus becomes a critical physical property to predict. It has been shown here that in order to do so, one simply needs the dry state glass transition temperature (T(g)) of the (co)polymer, the T(g) of water, and the saturated weight fraction of water for the sample in question. Facile calculation of the later can be achieved using water sorption data and the group additivity method. With these readily available data, we show that a form of the Flory-Fox equation can be used to predict the hydroplasticized state of copolymers in exceptional agreement with direct experimental measurement. Furthermore, extending the prediction to include the impact of the degree of ionization for pH responsive components, only with extra knowledge of the pK(a), was also validated by experiment.

  9. Electric field-driven, magnetically-stabilized ferro-emulsion phase contactor

    Science.gov (United States)

    Scott, Timothy C.

    1990-01-01

    Methods and systems for interfacial surface area contact between a dispersed phase liquid and a continuous phase liquid in counter-current flow for purposes such as solvent extraction. Initial droplets of a dispersed phase liquid material containing ferromagnetic particles functioning as a "packing" are introduced to a counter-current flow of the continuous phase. A high intensity pulsed electric field is applied so as to shatter the initial droplets into a ferromagnetic emulsion comprising many smaller daughter droplets having a greater combined total surface area than that of the initial droplets in contact with the continuous phase material. A magnetic field is applied to control the position of the ferromagnetic emulsion for enhanced coalescence of the daughter droplets into larger reformed droplets.

  10. Stimuli-triggered Formation of Polymersomes from W/O/W Multiple Double Emulsion Droplets Containing Poly(styrene)-block-poly(N-isopropylacrylamide-co-spironaphthoxazine methacryloyl).

    Science.gov (United States)

    Kim, Mi Ri; Cheong, In Woo

    2016-09-13

    We report stimuli-triggered fabrication of polymersomes from water-in-oil-in-water (W/O/W) multiple double emulsion droplets and the dual-stimuli (temperature and UV) responsive behavior of corresponding polymersomes. The polymersome comprises Tween20, cholesterol, and poly(styrene)-block-poly(N-isopropylacrylamide-co-spironaphthoxazine methacryloyl), i.e., PS-b-P(NIPAAm-co-SPO), synthesized by stepwise reversible addition-fragmentation chain transfer (RAFT) polymerization. Amphiphilic PS-b-P(NIPAAm-co-SPO) copolymer forms micelles in water above the critical micelle concentration (CMC) of 0.7 g/L at 23 °C. The micelles show a temperature-driven aggregation among the micelles above 30.6 °C, confirmed by a decrease in UV-vis transmittance. The micelles also show a color change without colloidal instability under 365 nm UV at room temperature. PS-b-P(NIPAAm-co-SPO) plays not only a role of the polymeric surfactant in the preparation of W/O/W multiple double emulsions but also an important role in the stimuli-triggered transformation from multi- to single-core double emulsion droplets under heat and UV light irradiation. It was found that the morphological transformation of W/O/W multiple double emulsions by UV irradiation was much faster than temperature change. Dual-responsive polymersomes were simply prepared after solvent removal and they exhibit stable and reversible size and color variations under temperature and UV-visible changes, respectively.

  11. Lipid emulsion therapy: non-nutritive uses of lipid emulsions in ...

    African Journals Online (AJOL)

    toxicity.1 However, the non-nutritive therapeutic roles of lipid emulsions have ... solving the toxicity associated with previous intravenous fat solutions.2 ..... Hu ZY, Peng XY, Liu F, et al. Emulsified ... prostaglandin metabolism. Chest. 1991 ...

  12. Application of pork fat diacylglycerols in meat emulsions

    DEFF Research Database (Denmark)

    Miklos, Rikke; Xu, Xuebing; Lametsch, René

    2011-01-01

    and binding properties were investigated in meat emulsions prepared with lard substituted with different amounts of DAGs derived from the lard. In emulsions prepared with DAGs the percentage of total expressible fluid decreased from 28.2% in products prepared with lard to 11.8% in emulsions prepared with 100......% DAGs. The fat separation decreased from 10.9% to 7.8% when 10% of DAGs were applied and no fat separation was observed for emulsions prepared with 50% and 100% DAGs. Emulsions containing DAGs were more elastic and solid reflected in a significant increase in Young's modulus and the maximum hardness...

  13. Performance of automatic scanning microscope for nuclear emulsion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Güler, A. Murat, E-mail: mguler@newton.physics.metu.edu.tr [Middle East Technical University, 06800 Ankara (Turkey); Altınok, Özgür [Middle East Technical University, 06800 Ankara (Turkey); Tufts University, Medford, MA 02155 (United States)

    2015-12-31

    The impressive improvements in scanning technology and methods let nuclear emulsion to be used as a target in recent large experiments. We report the performance of an automatic scanning microscope for nuclear emulsion experiments. After successful calibration and alignment of the system, we have reached 99% tracking efficiency for the minimum ionizing tracks that penetrating through the emulsions films. The automatic scanning system is successfully used for the scanning of emulsion films in the OPERA experiment and plan to use for the next generation of nuclear emulsion experiments.

  14. POLYMERIC NANOPARTICLES FROM SUPERCRITICAL CO2 MICROEMULSION POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Wei-jun Ye; Jason S. Keiper; Joseph M. DeSimone

    2006-01-01

    Herein, we reported the microemulsion polymerization in supercritical carbon dioxide. With the aid of an anionic phosphate fluorosurfactant (bis-[2-(F-hexyl)ethyl]phosphate sodium), water-soluble/CO2-insoluble acryloxyethyltrimethyl ammonium chloride monomer and N,N'-methylene-bisacrylamide cross-linker were solubilized into CO2 continuous phase via the formation of water-in-CO2 (w/c) microemulsion water pools. Initiated by a CO2-soluble initiator, 2,2'-azo-bisisobutyronitrile (AIBN), cross-linked poly(acryloxyethyltrimethyl ammonium chloride) particles were produced and stabilized in these w/c internal water pools. Nano-sized particles with sizes less than 20 nm in diameter and narrow particle size distributions were obtained.

  15. Carbon Dioxide-Water Emulsions for Enhanced Oil Recovery and Permanent Sequestration of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, David; Golomb, Dan; Shi, Guang; Shih, Cherry; Lewczuk, Rob; Miksch, Joshua; Manmode, Rahul; Mulagapati, Srihariraju; Malepati, Chetankurmar

    2011-09-30

    oilcontaining formations or saline aquifers. The term globule refers to the water or liquid carbon dioxide droplets sheathed with ultrafine particles dispersed in the continuous external medium, liquid CO{sub 2} or H{sub 2}O, respectively. The key to obtaining very small globules is the shear force acting on the two intermixing fluids, and the use of ultrafine stabilizing particles or nanoparticles. We found that using Kenics-type static mixers with a shear rate in the range of 2700 to 9800 s{sup -1} and nanoparticles between 100-300 nm produced globule sizes in the 10 to 20 μm range. Particle stabilized emulsions with that kind of globule size should easily penetrate oil-bearing formations or saline aquifers where the pore and throat size can be on the order of 50 μm or larger. Subsequent research focused on creating particle stabilized emulsions that are deemed particularly suitable for Permanent Sequestration of Carbon Dioxide. Based on a survey of the literature an emulsion consisting of 70% by volume of water, 30% by volume of liquid or supercritical carbon dioxide, and 2% by weight of finely pulverized limestone (CaCO{sub 3}) was selected as the most promising agent for permanent sequestration of CO{sub 2}. In order to assure penetration of the emulsion into tight formations of sandstone or other silicate rocks and carbonate or dolomite rock, it is necessary to use an emulsion consisting of the smallest possible globule size. In previous reports we described a high shear static mixer that can create such small globules. In addition to the high shear mixer, it is also necessary that the emulsion stabilizing particles be in the submicron size, preferably in the range of 0.1 to 0.2 μm (100 to 200 nm) size. We found a commercial source of such pulverized limestone particles, in addition we purchased under this DOE Project a particle grinding apparatus that can provide particles in the desired size range. Additional work focused on attempts to generate particle stabilized

  16. How does oil type determine emulsion characteristics in concentrated Na-caseinate emulsions?

    Science.gov (United States)

    Tan, Hui Lin; McGrath, Kathryn M

    2013-08-01

    Macroscopic properties and ensemble average diffusion of concentrated (dispersed phase 50-60 wt%) Na-caseinate-stabilised emulsions for three different oils (soybean oil, palm olein and tetradecane) were explored. On a volume fraction basis, pulsed gradient stimulated echo (PGSTE)-NMR data show that droplet dynamics for all three systems are similar within a region of the emulsion morphology diagram. The exact limits of the emulsion space depend however on which oil is considered. The reduced solubility of tetradecane in water, and Na-caseinate in tetradecane, result in the stabilisation of flocs during formulation. Floc formation is not observed when soybean oil or palm olein is used under identical emulsion formulation conditions. Linear rheology experiments provide indirect evidence that the local structure and the properties of the thin film interfacial domain of tetradecane emulsions vary from those of soybean oil and palm olein emulsions. Collectively these data indicate that protein/oil interactions within a system dominate over specific oil droplet structure and size distribution, which are similar in the three systems.

  17. CMS emulsion pictures during LS1

    CERN Multimedia

    Di Ferdinando, Donato

    2013-01-01

    These images were taken at the CMS experimental cavern during Long Shutdown 1, installing pinhole cameras at different points of the cavern and exposing them for days. The development of the film was done by Donato di Ferdinando from INFN Bologna. A pinhole camera is a light-tight box where a small hole is made (diameter of the order of microns); a light-sensitive material is set in the back of the hole. As sensitive material a nuclear emulsion film from the OPERA experiment was used. It is a special photographic emulsion optimized (silver grains enriched) for the detection of charged particles. A very large amount of nuclear emulsions where used in Opera experiment, at the Gran Sasso Underground Labs; nuclear emulsions must detect the charged tau-leptons emerging from the interaction between the "oscillated" tau-neutrino coming from the pure muon-neutrino beam produced at CERN (the CNGS beam). The oscillations theory of neutrino expects that muon neutrinos oscillate to tau-neutrinos and due to this behavior ...

  18. Emulsion flocculation induced by saliva and mucin

    NARCIS (Netherlands)

    Vingerhoeds, M.H.; Blijdenstein, T.B.J.; Zoet, F.D.; Aken, van G.A.

    2005-01-01

    Upon consumption of emulsions, mixing with saliva occurs. This article shows that whole saliva and a model mucin (pig gastric mucin, PGM) are able to induce extensive droplet flocculation. Saliva samples collected from several subjects at different times of the day always showed flocculation. Howeve

  19. Altering Emulsion Stability with Heterogeneous Surface Wettability

    NARCIS (Netherlands)

    Meng, Qiang; Zhang, Yali; Lammertink, Rob G.H.; Chen, Haosheng; Tsai, Peichun Amy

    2016-01-01

    Emulsions–liquid droplets dispersed in another immiscible liquid–are widely used in a broad spectrum of applications, including food, personal care, agrochemical, and pharmaceutical products. Emulsions are also commonly present in natural crude oil, hampering the production and quality of petroleum

  20. Immune modulation by parenteral lipid emulsions.

    NARCIS (Netherlands)

    Wanten, G.J.A.; Calder, P.C.

    2007-01-01

    Total parenteral nutrition is the final option for nutritional support of patients with severe intestinal failure. Lipid emulsions constitute the main source of fuel calories and fatty acids (FAs) in parenteral nutrition formulations. However, adverse effects on patient outcomes have been attributed

  1. Polymerized and functionalized triglycerides

    Science.gov (United States)

    Plant oils are useful sustainable raw materials for the development of new chemical products. As part of our research emphasis in sustainability and green polymer chemistry, we have explored a new method for polymerizing epoxidized triglycerides with the use of fluorosulfonic acid. Depending on the ...

  2. Waterborne Polymeric Films.

    Science.gov (United States)

    1981-02-01

    Skydrol 500B is a fire resistant hydraulic fluid available from Monsanto and which is primarily tricresyl phosphate. In most cases, the above table...Makromol. Chem. 1979, 82 149.- 23. Ger. Offen 2,804,609; (8/9/79). Bayer AG. 24. Odian, G. "Principles of Polymerization; "McGraw-Hill Book Co.: New York

  3. Physical Stability of Whippable Oil-in-Water Emulsions

    DEFF Research Database (Denmark)

    Munk, Merete Bøgelund

    is a prevalent problem causing deteriorated products. Increased viscosity is a consequence of aggregation of dispersed fat globules, which is referred to as physical instability. The aim of the project was to obtain detailed knowledge of the destabilization mechanisms in whippable emulsions by understanding...... on physical stability of whippable emulsions. Addition of LACTEM increased emulsion viscosity considerably at 20 °C, but low viscosity could almost be entirely regained by cooling the emulsions to 5 °C under appliance of shear. GMS did not induce fat globule aggregation in emulsions which remained low viscous...... was enhanced when GMU was added in combination with LACTEM. Physical stability of whippable emulsions was also influenced by concentrations of proteins and stabilizers, and type of dispersed fat phase. Factors related to the dispersed fat phase with effect on emulsion stability was solid fat content, broadness...

  4. Gelatin-hydroxypropyl methylcellulose water-in-water emulsions as a new bio-based packaging material.

    Science.gov (United States)

    Esteghlal, Sara; Niakosari, Mehrdad; Hosseini, Seyed Mohammad Hashem; Mesbahi, Gholam Reza; Yousefi, Gholam Hossein

    2016-05-01

    Gelatin and hydroxypropyl methylcellulose (HPMC) are two incompatible and immiscible biopolymers which cannot form homogeneous composite films using usual methods. In this study, to prevent phase separation, gelatin-HPMC water-in-water (W/W) emulsion was utilized to from transparent composite films by entrapment the HPMC dispersed droplets in gelatin continuous network. The physicochemical and mechanical properties of emulsion-based films containing different amounts (5-30%) of dispersed phase were determined and compared with those of individual polymer-based films. Incorporating HPMC into W/W emulsion-based films had no significant effect on the tensile strength. The flexibility of composite films decreased at HPMC concentrations below 20%. The depletion layer at the droplets interface reduced the diffusion of water vapor molecules because of its hydrophobic nature, so the water vapor permeability remained constant. Increasing the HPMC content in the emulsion films increased the swelling and decreased the transparency. The entrapment of HPMC in continuous gelatin phase decreased its solubility. Therefore, W/W emulsions are capable of holding two incompatible polymers alongside each other within a homogeneous film network without weakening the physical properties.

  5. Showing Emulsion Properties with Common Dairy Foods

    Science.gov (United States)

    Bravo-Diaz, Carlos; Gonzalez-Romero, Elisa

    1996-09-01

    Foods are mixtures of different chemical compounds, and the quality we sense (taste, texture, color, etc.) are all manifestations of its chemical properties. Some of them can be visualized with the aid of simple, safe and inexpensive experiments using dairy products that can be found in any kitchen and using almost exclusively kitchen utensils. In this paper we propose some of them related with food emulsions. Food emulsions cover an extremely wide area of daily-life applications such as milk, sauces, dressings and beverages. Experimentation with some culinary recipes to prepare them and the analyisis of the observed results is close to ideal subject for the introduction of chemical principles, allowing to discuss about the nature and composition of foods, the effects of additives, etc. At the same time it allows to get insights into the scientific reasons that underlie on the recipes (something that it is not usually found in most cookbooks). For example, when making an emulsion like mayonnaise, why the egg yolks and water are the first materials in the bowl , and the oil is added to them rather than in the other way around? How you can "rescue" separate emulsions (mayonnaise)? Which parameters affect emulsion stability? Since safety, in its broad sense, is the first requisite for any food, concerns about food exist throughout the world and the more we are aware of our everyday life, the more likely we will be to deal productively with the consequences. On the other hand, understanding what foods are and how cooking works destroys no delightful mystery of the art of cuisine, instead the mystery expands.

  6. High pressure inactivation of Clostridium botulinum type E endospores in model emulsion systems

    Science.gov (United States)

    Schnabel, Juliane; Lenz, Christian A.; Vogel, Rudi F.

    2015-01-01

    Clostridium botulinum type E is a cold-tolerant, neurotoxigenic, endospore-forming organism, primarily associated with aquatic environments. High pressure thermal (HPT) processing presents a promising tool to enhance food safety and stability. The effect of fat on HPT inactivation of C. botulinum type E spores was investigated using an emulsion model system. The distribution of spores in oil-in-water (O/W) emulsions and their HPT (300-750 MPa, 45-75 °C, 10 min) inactivation was determined as a function of emulsion fat content (30-70% (v/v) soybean oil in buffer). Approximately 26% and 74% of the spores were located at the oil-buffer interface and the continuous phase, respectively. Spore inactivation in emulsion systems decreased with increasing oil contents, which suggests that the fat content of food plays an important role in the protection of C. botulinum type E endospores against HPT treatments. These results can be helpful for future safety considerations. This paper was presented at the 8th International Conference on High Pressure Bioscience & Biotechnology (HPBB 2014), in Nantes (France), 15-18 July 2014.

  7. Effect of reactor's positions on polymerization and degradation in an ultrasonic field.

    Science.gov (United States)

    Kobayashi, Daisuke; Matsumoto, Hideyuki; Kuroda, Chiaki

    2008-03-01

    Ultrasonic generators are used as emulsifiers and efficient alternative initiators in polymerization processes. In this study, the effects of reactor's position on the emulsion polymerization of styrene under indirect ultrasonic irradiation were investigated, along with the effects of reactor's position on chemical and physical degradation. Both polymer yield and molecular weight were influenced by the position of the reactor. The ultrasonic irradiation could be divided into three stages, and the molecular weight of the polymer was influenced by polymerization and degradation processes. It was found that the extent of radical generation estimated by KI oxidation dosimetry and the shock wave index obtained from studies of degradation of standard polymer were useful for controlling the characteristics of the polymer generated.

  8. Two-step sequential cross-linking of sugar beet pectin for transforming zein nanoparticle-based Pickering emulsions to emulgels.

    Science.gov (United States)

    Soltani, Sahar; Madadlou, Ashkan

    2016-01-20

    Nanosized (<100 nm) zein spheres were employed for fabrication of a series of fish O/W Pickering emulsions. Although surface tension measurement informed the high potency of zein particles for interfacial adsorption, the prepared emulsions destabilized shortly. Electrostatic deposition of sugar beet pectin onto zein particles interfacial layer at pH 4.0 increased significantly the emulsion stability which was attributed to enhanced steric and electrostatic repulsions based on ζ-potential measurements. Pectin enrichment also increased the viscosity of the continuous phase of emulsion. Injection of the oxidative enzyme laccase into the pectin-enriched emulsion to cross-link the feruloyl-bearing pectin molecules and the subsequent addition of CaCl2 to set ion-mediated cross-linkages between carboxyl groups of pectin chains transformed Pickering emulsions to emulgels. The higher the pectin content, the shorter was the gelation time of emulsions. The obtained emulgels were self-standing and became harder along with increasing pectin content.

  9. 氟硅丙烯酸酯/钠基蒙脱土复合乳胶涂层的制备及防腐蚀性能%Preparation and anticorrosion performance of fluorine-silicon-acrylate/sodium montmorillonite composite emulsion coating

    Institute of Scientific and Technical Information of China (English)

    高晓辉; 李玉峰; 祝晶晶; 张毅志

    2015-01-01

    以甲基丙烯酸十二氟庚酯和乙烯基三甲氧基硅烷为功能单体,采用种子乳液聚合法合成氟硅丙烯酸酯乳液(氟硅),然后将钠基蒙脱土(钠土)分散于其中,制成复合乳胶涂层并涂覆在Q235钢上。研究了乳液种类和钠土用量对涂层防腐性的影响。采用红外光谱(FT-IR)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)表征了氟硅丙烯酸酯乳液和涂层。通过极化曲线、交流阻抗测量和中性盐雾试验探讨了复合涂层的耐腐蚀性。结果表明,乳胶粒子呈核壳结构,涂层连续、致密,钠土在涂层中分散均匀。当钠土用量为4%时,复合涂层的耐蚀性最好,水接触角达到102.4°,附着力为0级,电化学阻抗达到104.4Ω,腐蚀速率仅为4.3×10−5 mm/a,盐雾试验240 h后膜下金属未发生腐蚀扩散。%A fluorine-silicon-acrylate emulsion was synthesized by seed emulsion polymerization using dodecafluoroheptyl methacrylate and vinyltrimethoxysilane as monomers. Sodium montmorillonite (Na-MMT) was dispersed in the fluorine-silicon-acrylate emulsion for preparing a composite emulsion coating for Q235 steel. The influences of emulsion type and Na-MMT content on anticorrosion properties of the coating were studied. The fluorine-silicon-acrylate emulsion and coating were characterized by Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The corrosion resistance of the composite coating was examined by polarization curve measurement, electrochemical impedance spectroscopy, and neutral salt spray test. The results showed that the emulsion particles possess obvious core-shell structure and the composite coating is continuous and compact with well-dispersed Na-MMT. The composite emulsion coating obtained with 4%Na-MMT has optimal anticorrosion performance with a water contact angle of 102.4°, adhesion strength of 0 grade

  10. Optical Properties of the Self-Assembling Polymeric Colloidal Systems

    Directory of Open Access Journals (Sweden)

    Alexandra Mocanu

    2013-01-01

    Full Text Available In the last decade, optical materials have gained much interest due to the high number of possible applications involving path or intensity control and filtering of light. The continuous emerging technology in the field of electrooptical devices or medical applications allowed the development of new innovative cost effective processes to obtain optical materials suited for future applications such as hybrid/polymeric solar cells, lasers, polymeric optical fibers, and chemo- and biosensing devices. Considering the above, the aim of this review is to present recent studies in the field of photonic crystals involving the use of polymeric materials.

  11. PLGA nanoparticles from nano-emulsion templating as imaging agents: Versatile technology to obtain nanoparticles loaded with fluorescent dyes.

    Science.gov (United States)

    Fornaguera, C; Feiner-Gracia, N; Calderó, G; García-Celma, M J; Solans, C

    2016-11-01

    The interest in polymeric nanoparticles as imaging systems for biomedical applications has increased notably in the last decades. In this work, PLGA nanoparticles, prepared from nano-emulsion templating, have been used to prepare novel fluorescent imaging agents. Two model fluorescent dyes were chosen and dissolved in the oil phase of the nano-emulsions together with PLGA. Nano-emulsions were prepared by the phase inversion composition (PIC) low-energy method. Fluorescent dye-loaded nanoparticles were obtained by solvent evaporation of nano-emulsion templates. PLGA nanoparticles loaded with the fluorescent dyes showed hydrodynamic radii lower than 40nm; markedly lower than those reported in previous studies. The small nanoparticle size was attributed to the nano-emulsification strategy used. PLGA nanoparticles showed negative surface charge and enough stability to be used for biomedical imaging purposes. Encapsulation efficiencies were higher than 99%, which was also attributed to the nano-emulsification approach as well as to the low solubility of the dyes in the aqueous component. Release kinetics of both fluorescent dyes from the nanoparticle dispersions was pH-independent and sustained. These results indicate that the dyes could remain encapsulated enough time to reach any organ and that the decrease of the pH produced during cell internalization by the endocytic route would not affect their release. Therefore, it can be assumed that these nanoparticles are appropriate as systemic imaging agents. In addition, in vitro toxicity tests showed that nanoparticles are non-cytotoxic. Consequently, it can be concluded that the preparation of PLGA nanoparticles from nano-emulsion templating represents a very versatile technology that enables obtaining biocompatible, biodegradable and safe imaging agents suitable for biomedical purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Emulsifying salt increase stability of cheese emulsions during holding

    DEFF Research Database (Denmark)

    Hougaard, Anni Bygvrå; Sijbrandij, Anna G.; Varming, Camilla

    2015-01-01

    In cheese powder production, cheese is mixed and melted with water and emulsifying salt to form an emulsion (cheese feed) which is required to remain stable at 60°C for 1h and during further processing until spray drying. Addition of emulsifying salts ensures this, but recent demands for reduction...... of sodium and phosphate in foods makes production of cheese powder without or with minimal amounts of emulsifying salts desirable. The present work uses a centrifugation method to characterize stability of model cheese feeds. Stability of cheese feed with emulsifying salt increased with holding time at 60°C......, especially when no stirring was applied. No change in stability during holding was observed in cheese feeds without emulsifying salt. This effect is suggested to be due to continued exerted functionality of the emulsifying salt, possibly through reorganizations of the mineral balance....

  13. Coalescence of Pickering Emulsion Droplets Induced by an Electric Field

    Science.gov (United States)

    Chen, Guo; Tan, Peng; Chen, Shuyu; Huang, Jiping; Wen, Weijia; Xu, Lei

    2013-02-01

    Combining high-speed photography with electric current measurement, we investigate the electrocoalescence of Pickering emulsion droplets. Under a high enough electric field, the originally stable droplets coalesce via two distinct approaches: normal coalescence and abnormal coalescence. In the normal coalescence, a liquid bridge grows continuously and merges two droplets together, similar to the classical picture. In the abnormal coalescence, however, the bridge fails to grow indefinitely; instead, it breaks up spontaneously due to the geometric constraint from particle shells. Such connecting-then-breaking cycles repeat multiple times, until a stable connection is established. In depth analysis indicates that the defect size in particle shells determines the exact merging behaviors: when the defect size is larger than a critical size around the particle diameter, normal coalescence will show up, while abnormal coalescence will appear for coatings with smaller defects.

  14. Coalescence of Pickering emulsion droplets induced by electric-field

    Science.gov (United States)

    Chen, Guo; Tan, Peng; Chen, Shuyu; Huang, Jiping; Wen, Weijia; Xu, Lei

    2013-03-01

    Combining high-speed photography with electric current measurement, we investigate the coalescence of Pickering emulsion droplets. Under high enough electric field, the originally-stable droplets coalesce via two distinct approaches: normal coalescence and abnormal coalescence. In the normal coalescence, a liquid bridge grows continuously and merges two droplets together, similar to the classical picture. In the abnormal coalescence, however, the bridge fails to grow indefinitely; instead it breaks up spontaneously due to the geometric constraint from particle shells. Such connecting-then-breaking cycles repeat multiple times, until a stable connection is established. In depth analysis indicates that the defect size in particle shells determines the exact merging behaviors: when the defects are larger than a critical size, normal coalescence will show up; while abnormal coalescence will appear for smaller defects. This project is supported by the Hong Kong GRF Grant (Project No. CUHK404211).

  15. Modeling and simulation of milk emulsion drying in spray dryers

    Directory of Open Access Journals (Sweden)

    V. S. Birchal

    2005-06-01

    Full Text Available This work aims at modeling and simulating the drying of whole milk emulsion in spray dryers. Drops and particles make up the discrete phase and are distributed into temporal compartments following their residence time in the dryer. Air is the continuous and well-mixed phase. Mass and energy balances are developed for each phase, taking into account their interactions. Constitutive equations for describing the drop swelling and drying mechanisms as well as the heat and mass transfer between particles and hot air are proposed and analyzed. A set of algebraic-differential equations is obtained and solved by specific numerical codes. Results from experiments carried out in a pilot spray dryer are used to validate the model developed and the numerical algorithm. Comparing the simulated and experimental data, it is shown that the model predicts well the individual drop-particle history inside the dryer as well as the overall outlet air-particle temperature and humidity.

  16. Stability of Concentrated Olive Oil-in-water Emulsion

    Institute of Scientific and Technical Information of China (English)

    TAN Hsiao-Wei; MISRAN Mi-sni

    2008-01-01

    The stability of olive oil-in-water(o/w)emulsion stabilized with sucrose fatty acid ester(SFAE)was evaluated through an accelerated ageing test.The stability of the emulsion in this study was examined by the appearance of any phase separation in the emulsion,mean droplet size and rbeological properties over one month.The effect of accelerated ageing at 45 μ on the emulsion rheological properties was investigated using an amplitude sweep test,a frequency sweep test and a viscometry test.The rheological properties of the emulsion were examined at the one day,one week and one month of storage time.Among the series of emulsions prepared,the emulsion with 2 :8 of water to oil ratio(by weight)is the most stable one,which did not show any of phase separation.The amplitude sweep result shows that there was no significant change of the critical strain of the emulsion throughout one month of storage time.The dynamic properties as well as the steady flow behavior of the emulsion also show no significant changes for over one month of storage time.The mean droplet size of the emulsion remained stable around 2.5 μn within the period of investigation.

  17. Modeling of continuous free-radical butadiene-styrene copolymerization process by the Monte Carlo method

    Directory of Open Access Journals (Sweden)

    T. A. Mikhailova

    2016-01-01

    Full Text Available In the paper the algorithm of modeling of continuous low-temperature free-radical butadiene-styrene copolymerization process in emulsion based on the Monte-Carlo method is offered. This process is the cornerstone of industrial production butadiene – styrene synthetic rubber which is the most widespread large-capacity rubber of general purpose. Imitation of growth of each macromolecule of the formed copolymer and tracking of the processes happening to it is the basis of algorithm of modeling. Modeling is carried out taking into account residence-time distribution of particles in system that gives the chance to research the process proceeding in the battery of consistently connected polymerization reactors. At the same time each polymerization reactor represents the continuous stirred tank reactor. Since the process is continuous, it is considered continuous addition of portions to the reaction mixture in the first reactor of battery. The constructed model allows to research molecular-weight and viscous characteristics of the formed copolymerization product, to predict the mass content of butadiene and styrene in copolymer, to carry out calculation of molecular-weight distribution of the received product at any moment of conducting process. According to the results of computational experiments analyzed the influence of mode of the process of the regulator introduced during the maintaining on change of characteristics of the formed butadiene-styrene copolymer. As the considered process takes place with participation of monomers of two types, besides listed the model allows to research compositional heterogeneity of the received product that is to carry out calculation of composite distribution and distribution of macromolecules for the size and structure. On the basis of the proposed algorithm created the software tool that allows you to keep track of changes in the characteristics of the resulting product in the dynamics.

  18. STABILITY OF EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE/ BUTYL ACRYLATE/SODIUM MONO(ETHYL POLYOXYETHYLENE) MALEATE

    Institute of Scientific and Technical Information of China (English)

    Mao-gen Zhang; Zhi-xue Weng; Zhi-ming Huang; Zu-ren Pan

    1999-01-01

    A series of new water-soluble bifunctional comonomers having both carboxyl and alkyl polyoxyethylene groups, such as sodium mono(ethyl polyoxyethylene) maleate (ZE series) with various molecular weights of polyoxyethylene ethyl ether, were synthesized and characterized. The effects of the structural factor, the amount and feeding mode of the comonomers, the initiator concentration and polymerization temperature on the stability of emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate (BA) in the presence of a small amount of ZE with potassium persulfate as initiator were investigated. Stable, almost monodispersed MMA/BA/ZE emulsifier-free latex particles were prepared.

  19. Photonic band gap effect and structural color from silver nanoparticle gelatin emulsion.

    Science.gov (United States)

    Kok, Mang Hin; Ma, Rui; Lee, Jeffrey Chi Wai; Tam, Wing Yim; Chan, C T; Sheng, Ping; Cheah, Kok Wai

    2005-10-01

    We have fabricated planar structures of silver nanoparticles in monochromatic gelatin emulsion with a continuous spacing ranging from 0.15-0.40 micron using a two-beam interference of a single laser source. Our planar holograms display a colorful "rainbow" pattern and photonic bandgaps covering the visible and IR ranges. We model the planar silver nanoparticle-gelatin composite system using an effective medium approach and good agreement is obtained between theory and experiment.

  20. Layer-by-layer encapsulated nano-emulsion of ionic liquid loaded with functional material for extraction of Cd(2+) ions from aqueous solutions.

    Science.gov (United States)

    Elizarova, Iuliia S; Luckham, Paul F

    2017-04-01

    Ionic liquids can serve as an environmentally-friendly replacement for solvents in emulsions, therefore they are considered suitable to be used as an emulsified medium for various active materials one of which are extractors of metal ions. Increasing the extraction efficiency is considered to be one of the key objectives when working with such extraction systems. One way to improve the extraction efficiency is to increase the contact area between the extractant and the working ionic solution. This can be accomplished by creating a nano-emulsion of ionic liquid containing such an extractant. Since emulsification of ionic liquid is not always possible in the sample itself, there is a necessity of creating a stable emulsion that can be added externally and on demand to samples from which metal ions need to be extracted. We propose a method of fabrication of a highly-stable extractant-loaded ionic liquid-in-water nano-emulsion via a low-energy phase reversal emulsification followed by continuous layer-by-layer polyelectrolyte deposition process to encapsulate the nano-emulsion and enhance the emulsion stability. Such a multilayered stabilized nano-emulsion was tested for extraction of Cd(2+) and Ca(2+) ions in order to determine its extraction efficiency and selectivity. It was found to be effective in the extraction of Cd(2+) ions with near 100% cadmium removal, as well as being selective since no Ca(2+) ions were extracted. The encapsulated emulsion was removed from samples post-extraction using two methods - filtration and magnetic separation, both of which were shown to be viable under different circumstances - larger and mechanically stronger capsules could be removed by filtration, however magnetic separation worked better for both smaller and bigger capsules. The long-term stability of nano-emulsion was also tested being a very important characteristic for its proposed use: it was found to be highly stable after four months of storage time.

  1. A Comparative Study of the Physicochemical Properties of a Virgin Coconut Oil Emulsion and Commercial Food Supplement Emulsions

    Directory of Open Access Journals (Sweden)

    Yih Phing Khor

    2014-07-01

    Full Text Available Food manufacturers are interested in developing emulsion-based products into nutritional foods by using beneficial oils, such as fish oil and virgin coconut oil (VCO. In this study, the physicochemical properties of a VCO oil-in-water emulsion was investigated and compared to other commercial oil-in-water emulsion products (C1, C2, C3, and C4. C3 exhibited the smallest droplet size of 3.25 µm. The pH for the emulsion samples ranged from 2.52 to 4.38 and thus were categorised as acidic. In a texture analysis, C2 was described as the most firm, very adhesive and cohesive, as well as having high compressibility properties. From a rheological viewpoint, all the emulsion samples exhibited non-Newtonian behaviour, which manifested as a shear-thinning property. The G'G'' crossover illustrated by the VCO emulsion in the amplitude sweep graph but not the other commercial samples illustrated that the VCO emulsion had a better mouthfeel. In this context, the VCO emulsion yielded the highest zeta potential (64.86 mV, which was attributed to its strong repulsive forces, leading to a good dispersion system. C2 comprised the highest percentage of fat among all emulsion samples, followed by the VCO emulsion, with 18.44% and 6.59%, respectively.

  2. A comparative study of the physicochemical properties of a virgin coconut oil emulsion and commercial food supplement emulsions.

    Science.gov (United States)

    Khor, Yih Phing; Koh, Soo Peng; Long, Kamariah; Long, Shariah; Ahmad, Sharifah Zarah Syed; Tan, Chin Ping

    2014-07-01

    Food manufacturers are interested in developing emulsion-based products into nutritional foods by using beneficial oils, such as fish oil and virgin coconut oil (VCO). In this study, the physicochemical properties of a VCO oil-in-water emulsion was investigated and compared to other commercial oil-in-water emulsion products (C1, C2, C3, and C4). C3 exhibited the smallest droplet size of 3.25 µm. The pH for the emulsion samples ranged from 2.52 to 4.38 and thus were categorised as acidic. In a texture analysis, C2 was described as the most firm, very adhesive and cohesive, as well as having high compressibility properties. From a rheological viewpoint, all the emulsion samples exhibited non-Newtonian behaviour, which manifested as a shear-thinning property. The G'G'' crossover illustrated by the VCO emulsion in the amplitude sweep graph but not the other commercial samples illustrated that the VCO emulsion had a better mouthfeel. In this context, the VCO emulsion yielded the highest zeta potential (64.86 mV), which was attributed to its strong repulsive forces, leading to a good dispersion system. C2 comprised the highest percentage of fat among all emulsion samples, followed by the VCO emulsion, with 18.44% and 6.59%, respectively.

  3. Multivesicular Emulsion Ceramide-containing Moisturizers: An Evaluation of Their Role in the Management of Common Skin Disorders

    Science.gov (United States)

    Del Rosso, James Q.

    2016-01-01

    Proper stratum corneum function plays a pivotal role in maintenance of skin health, and improper function leads to skin disease. The stratum corneum is comprised of corneocytes surrounded by intercelluar lipids including ceramides, free fatty acids, and cholesterol. Ceramide predominant moisturizers have become a mainstay of treatment of skin disease. New technologies for delivery of ceramides include multivesicular emulsions, which deposit ceramides in a timerelease manner for a continuous rather than burst effect. Here, the authors review the available data on the use of multivesicular emulsion ceramide moisturizers in various skin diseases. PMID:28210396

  4. Evidence for Marginal Stability in Emulsions

    Science.gov (United States)

    Lin, Jie; Jorjadze, Ivane; Pontani, Lea-Laetitia; Wyart, Matthieu; Brujic, Jasna

    2016-11-01

    We report the first measurements of the effect of pressure on vibrational modes in emulsions, which serve as a model for soft frictionless spheres at zero temperature. As a function of the applied pressure, we find that the density of states D (ω ) exhibits a low-frequency cutoff ω*, which scales linearly with the number of extra contacts per particle δ z . Moreover, for ω Soft Matter 10, 5628 (2014); S. Franz, G. Parisi, P. Urbani, and F. Zamponi, Proc. Natl. Acad. Sci. U.S.A. 112, 14539 (2015)]. Finally, the degree of localization of the softest low frequency modes increases with compression, as shown by the participation ratio as well as their spatial configurations. Overall, our observations show that emulsions are marginally stable and display non-plane-wave modes up to vanishing frequencies.

  5. Recent advances in heavy oil emulsion treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dabros, T.; Hamza, H.A. [CANMET Energy Technology Centre, Devon, AB (Canada)

    2006-07-01

    The challenge of removing emulsified water and dispersed fine solids can be addressed by using a combination of mechanical and thermal treatments assisted by the addition of surfactants and solvent. This paper presented some new developments in the characterization and treatment of heavy oil emulsions. These included the optimization of surfactant (demulsifier) selection and the influence of solvent composition on emulsion stability. The paper discussed reasons for different degrees of decontamination with surfactants and solvent treatment. A new method of determining the droplet size distribution, based on the theory of hindered settling was also presented. It was concluded that the proposed method of determining the size distribution of emulsified water droplets based on examination of hindered settling process in combination with analytical data on water content in the diluted bitumen as a function of time is useful for opaque systems in which standard techniques such as microscopy and light scattering fail. 6 refs., 4 figs.

  6. Entropically Driven Colloidal Assembly in Emulsions

    Science.gov (United States)

    Lin, Keng-Hui; Lai, Liang-Jie; Chen, Hui

    2007-03-01

    Using the techniques developed by Manoharan [1], we encapsulate small numbers of colloidal microspheres and polymers in oil-in-water emulsion droplets, remove the oil and generate colloidal clusters covered with polymers. We observe two types of arrangement in the clusters. The first kind is the same as the type reported in [1] of which the clusters are formed without polymer. The second kind is the same as the structure reported in [2] of which the clusters are formed by binary colloidal microspheres. The polymers we put in the emulsions induce depletion interactions between colloidal particles. We will show that two types of structures are from the interplay between the depletion interactions and surface tension. [1] Manoharan, Elsesser, Pine, Science 301, 483(2003). [2] Cho et al. JACS 127, 15968 (2005).

  7. Glycerol effects on the formation and rheology of hexagonal phase and related gel emulsion.

    Science.gov (United States)

    Alam, Mohammad Mydul; Aramaki, Kenji

    2009-08-15

    We have investigated the effects of glycerol on the formation and rheology of hexagonal phase (H(1)) and related O/H(1) gel emulsion in the water/C(12)EO(8)/dodecane system at 25 degrees C. It has been found that the aqueous solution of C(12)EO(8) forms H(1) phase, which could solubilize some amounts of dodecane. Beyond the solubilization limit, oil is separated and a two-phase region or H(1)+O phase appeared. Due to high viscosity of the H(1) phase, allows forming O/H(1) gel emulsion at the H(1)+O region. Rheological measurements (without glycerol) have shown that the rheogram of the H(1) phase does not change drastically with the addition of oil but the system is shifted to longer relaxation time. Simultaneously, the values of the absolute value(eta(*)) are found to increase with the addition of oil, which has been described with the neighboring micellar interaction. The rheogram of the O/H(1) gel emulsion shows gel type nature (G'>G'') but the viscosity monotonically decreases with increasing oil content, which could be due to the lower volume fraction of the continuous phase (H(1) phase). Addition of glycerol has brought an order-order transition or the microstructural transition from H(1)-lamellar (L(alpha)) phase, which is manifested from rheology and SAXS measurements. Viscosity of the O/H(1) gel emulsion also decreases with increasing glycerol content. Digital images show the physical appearance of the gel emulsion changes from turbid to transparent, which is depended on the glycerol concentration (since glycerol matches the refractive index of the H(1) phase and dodecane). Structural parameters of the H(1) phase have been evaluated with the help of Bohlin's model and found that the coordination number of the H(1) phase depends not only the oil and glycerol concentrations but also temperature.

  8. Physical Stability of Whippable Oil-in-Water Emulsions

    DEFF Research Database (Denmark)

    Munk, Merete Bøgelund

    the impact of ingredient composition, with focus on low-molecular-weight (LMW) emulsifiers. Three monoglyceride-based LMW-emulsifiers were selected: Lactic acid ester of saturated monoglyceride (LACTEM), unsaturated monoglyceride (GMU), and saturated monoglyceride (GMS). LMW-emulsifiers had major impact...... on physical stability of whippable emulsions. Addition of LACTEM increased emulsion viscosity considerably at 20 °C, but low viscosity could almost be entirely regained by cooling the emulsions to 5 °C under appliance of shear. GMS did not induce fat globule aggregation in emulsions which remained low viscous...... despite appliance of shear and temperature changes from 5 to 20 °C. Globule aggregation induced by LACTEM was impeded when used in combination with GMS. On the contrary, GMU induced very dense fat globule networks in emulsions which transformed emulsions into very firm solid-like pastes. This effect...

  9. Emulsions Containing Perfluorocarbon Support Cell Cultures

    Science.gov (United States)

    Ju, Lu-Kwang; Lee, Jaw Fang; Armiger, William B.

    1990-01-01

    Addition of emulsion containing perfluorocarbon liquid to aqueous cell-culture medium increases capacity of medium to support mammalian cells. FC-40 Fluorinert (or equivalent) - increases average density of medium so approximately equal to that of cells. Cells stay suspended in medium without mechanical stirring, which damages them. Increases density enough to prevent cells from setting, and increases viscosity of medium so oxygen bubbled through it and nutrients stirred in with less damage to delicate cells.

  10. Vegetable oil based emulsions in milk

    OpenAIRE

    Veronika Mikulcová; Iva Hauerlandová; Leona Buňková

    2014-01-01

    Milk and dairy products represent an important part of functional food in the market. Based on their positive health and nutritional benefits, they have gained popularity and their consumption as well as production is on the rise in the last few decades. As a result of this trend, milk-based products are being used for the delivery of bioactive food ingredients. This study is devoted to the formulation of stable emulsions containing grape seed oil dispersed with several emulsifiers (Tween 80,...

  11. Omega-3s in food emulsions

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte

    2008-01-01

    There is an increasing interest in the use of healthy long chain omega-3 oils in foods. Incorporation of omega-3 oils into foods decreases their oxidative stability and therefore precautions need to be taken to avoid lipid oxidation. This review summarises the major factors to take into considera...... into consideration when developing food emulsions enriched with omega-3 oils and examples on how oxidation can be reduced in products such as mayonnaise, spreads, milk, yoghurt are also given....

  12. Simulation of phase separation with large component ratio for oil-in-water emulsion in ultrasound field.

    Science.gov (United States)

    Wang, Heping; Li, Xiaoguang; Li, Yanggui; Geng, Xingguo

    2017-05-01

    This paper presents an exploration for separation of oil-in-water and coalescence of oil droplets in ultrasound field via lattice Boltzmann method. Simulations were conducted by the ultrasound traveling and standing waves to enhance oil separation and trap oil droplets. The focus was to the effect of ultrasound irradiation on oil-in-water emulsion properties in the standing wave field, such as oil drop radius, morphology and growth kinetics of phase separation. Ultrasound fields were applied to irradiate the oil-in-water emulsion for getting flocculation of the oil droplets in 420kHz case, and larger dispersed oil droplets and continuous phases in 2MHz and 10MHz cases, respectively. The separated phases started to rise along the direction of sound propagation after several periods. The rising rate of the flocks was significantly greater in ultrasound case than that of oil droplets in the original emulsion, indicating that ultrasound irradiation caused a rapid increase of oil droplet quantity in the progress of the separation. The separation degree was also significantly improved with increasing frequency or irradiation time. The dataset was rearranged for growth kinetics of ultrasonic phase separation in a plot by spherically averaged structure factor and the ratio of oil and emulsion phases. The analyses recovered the two different temporal regimes: the spinodal decomposition and domain growth stages, which further quantified the morphology results. These numerical results provide guidance for setting the optimum condition for the separation of oil-in-water emulsion in the ultrasound field.

  13. Fouling reduction by ozone-enhanced backwashing process in ultrafiltration of petroleum-based oil in water emulsion

    Science.gov (United States)

    Aryanti, Nita; Prihatiningtyas, Indah; Kusworo, Tutuk Djoko

    2017-06-01

    Ultrafiltration membrane has been successfully applied for oily waste water treatment. However, one significant drawback of membrane technology is fouling which is responsible for permeate flux decline as well as reducing membrane performance. One method commonly used to reduce fouling is a backwashing process. The backwashing is carried out by a push of reversed flow from permeate side to the feed side of a membrane to remove fouling on the membrane pore and release fouling release fouling layer on the external side. However, for adsorptive fouling, the backwashing process was not effective. On the other hand, Ozone demonstrated great performance for reducing organics fouling. Hence this research was focused on backwashing process with ozone for removing fouling due to ultrafiltration of petroleum based oil emulsion. Gasoline and diesel oil were selected as dispersed phase, while as continuous phase was water added with Tween 80 as a surfactant. This research found that the Ozone backwashing was effective to improve flux recovery. In ultrafiltration of gasoline emulsion, the flux recovery after Ozone backwashing was in the range of 42-74%. For ultrafiltration of diesel oil emulsion, the permeate flux recovery was about 35-84%. In addition, foulant deposition was proposed and predicting that foulant deposition for ultrafiltration of gasoline-in-water emulsion was surfactant as the top layer and the oil was underneath the surfactant. On the other hand, for ultrafiltration of diesel oil-in-water emulsion, the oil was predicted as a top layer above the surfactant foulant.

  14. Simple and double emulsions via electrospray

    Science.gov (United States)

    Barrero, Antonio; Loscertales, Ignacio G.

    2005-11-01

    Generation of nanoemulsions is of great interest in medical and pharmaceutical applications; drug delivery or antiviral emulsions are typical examples. The use of electrosprays for dispersing liquids inside liquid insulator baths have been recently reported, (Barrero et al. J. Colloid Interf. Sci. 272, 104, 2004). Capsules, nanotubes and coaxial nanofibers have been obtained from electrified coaxial jets (Loscertales et al. Science 295, n. 5560, 1695, 2002; J. American Chem. Soc. 126, 5376, 2004). Here we present a method for making double emulsions (both water-oil-water and o/w/o) based on the generation of compound electrosprays inside insulator liquid baths. Basically, a conducting liquid injected throughout a capillary needle is electroatomized in cone-jet mode inside a dielectric liquid bath. A third insulating liquid is injected inside the Taylor cone to form a second meniscus. Then, a steady coaxial jet, in which the insulating liquid is coated by the conducting one, develops. A double emulsion forms as a result of the jet breaking up into compound droplets electrically charged. Experimental results carried out with glycerine and different oils in a bath of heptane are reported.

  15. Simulations of a dielectrophoretic membrane filtration process for removal of water droplets from water-in-oil emulsions.

    Science.gov (United States)

    Molla, Shahnawaz H; Masliyah, Jacob H; Bhattacharjee, Subir

    2005-07-01

    A novel separation technique based on simultaneous application of AC dielectrophoresis and preferential transport through a semipermeable hydrophilic membrane is proposed for separation of small amounts of emulsified water droplets from a water-in-oil emulsion. Embedding an array of parallel microelectrodes on a membrane matrix, followed by application of an AC potential to these electrodes, can result in capturing the water droplets onto the membranes from the emulsion during a crossflow filtration process. The present paper describes the theoretical principles underlying such a process, and describes a simple mathematical framework based on trajectory analysis for assessing the separation efficiency of such a technique. The results indicate that superimposition of an AC dielectrophoretic field can significantly enhance the preferential transport of the emulsified water through the membrane in a crossflow filtration device. This can lead to a highly efficient continuous separation process for dilute emulsions.

  16. Emulsifier development for high-concentrated reverse emulsions

    OpenAIRE

    Kovalenko, I. L.; V.P. Kuprin

    2016-01-01

    The reverse emulsions have found broad application in ore mining industry as matrixes of emulsion explosive substances and boring washing waters. The defining characteristic of reverse emulsions of industrial explosive substances is the high stability and immunity to crystallization. Aim: The aim of this work is to assess the mechanism of emulsifiers effect like SMO and some PIBSA-derivatives, that are most abundantly used in world practice, and also to develop an effective domestic emulsifie...

  17. Characterization and stability studies of emulsion systems containing pumice

    OpenAIRE

    Marilene Estanqueiro; Jaime Conceição; Maria Helena Amaral; Delfim Santos; João Baptista Silva; José Manuel Sousa Lobo

    2014-01-01

    Emulsions are the most common form of skin care products. However, these systems may exhibit some instability. Therefore, when developing emulsions for topical application it is interesting to verify whether they have suitable physical and mechanical characteristics and further assess their stability. The aim of this work was to study the stability of emulsion systems, which varied in the proportion of the emulsifying agent cetearyl alcohol (and) sodium lauryl sulfate (and) sodium cetearyl su...

  18. Antioxidant efficacy of caffeates in emulsions and the effect of tocopherols

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Aleman, M.; Durand, E.

    2013-01-01

    was evaluated from three parameters measured over time: peroxide value (PV), secondary volatile oxidation products and tocopherol concentrations. The results demonstrate the efficacy of caffeates in simple emulsions and food emulsions. Furthermore, the two different simple emulsion systems reveal possible...

  19. The choice of homogenisation equipment affects lipid oxidation in emulsions

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Jensen, Louise Helene Søgaard

    2012-01-01

    in emulsions has been shown to be affected by the emulsification conditions. The objective of this study was to investigate the influence of homogenisation equipment (microfluidizer vs. two-stage valve homogeniser) on lipid oxidation in 10% fish oil-in-water emulsions prepared with two different milk proteins....... Emulsions were prepared at pH 7 with similar droplet sizes. Results showed that the oxidative stability of emulsions prepared with sodium caseinate was not influenced by the type of homogeniser used. In contrast, the type of homogenisation equipment significantly influenced lipid oxidation when whey protein...

  20. Squalene Emulsions for Parenteral Vaccine and Drug Delivery

    Directory of Open Access Journals (Sweden)

    Christopher B. Fox

    2009-09-01

    Full Text Available Squalene is a linear triterpene that is extensively utilized as a principal component of parenteral emulsions for drug and vaccine delivery. In this review, the chemical structure and sources of squalene are presented. Moreover, the physicochemical and biological properties of squalene-containing emulsions are evaluated in the context of parenteral formulations. Historical and current parenteral emulsion products containing squalene or squalane are discussed. The safety of squalene-based products is also addressed. Finally, analytica techniques for characterization of squalene emulsions are examined.

  1. Interaction between a perfluorocarbon emulsion and radiographic contrast media.

    Science.gov (United States)

    Franke, Ralf-Peter; Reuter, Peter; Röhlke, Wolfgang; Matschke, Klaus; Keller, Steffi; Klosterhalfen, Bernd; Mittermayer, Christian; Mrowietz, Christoph; Jung, Friedrich

    2004-03-01

    This study evaluated specially designed perfluorocarbon (PFC) emulsions as blood substitutes in case of induced ischemia of the left heart ventricle in healthy farm pigs. Two hundred ml of perfluorocarbon emulsion were infused while 200 ml of blood were simultaneously drawn. Radiographic contrast media were given to aid placement of balloon catheters in the left coronary artery. Histopathological analysis showed that right heart failure caused the deaths of both pigs. Particles (up to>3 micro) of foreign body materials obstructed capillaries of all organs analyzed (heart, lung, liver, kidneys and spleen). Laboratory investigation showed severe interference between the PFC emulsion and radiographic contrast media, resulting in the deterioration of the PFC emulsion. The strongest interference occurred when PFC emulsion and Accupaque interacted; particle size started at an initial 311 nm and went up to >3 micro within seconds. Great care must be taken when PFC emulsions are used in combination with x-ray contrast media. None of the described radiographic contrast media should be used within 48 hours prior to the use of this PFC emulsion. Also, the use of these contrast media should be avoided for a certain period of time after using PFC emulsion. The mechanisms of elimination of PFC emulsions from the circulation are not completely understood and has yet to be evaluated.

  2. Performance evaluation of organic emulsion liquid membrane on phenol removal

    CERN Document Server

    Ng, Y S; Hashim, M A

    2014-01-01

    The percentage removal of phenol from aqueous solution by emulsion liquid membrane and emulsion leakage was investigated experimentally for various parameters such as membrane:internal phase ratio, membrane:external phase ratio, emulsification speed, emulsification time, carrier concentration, surfactant concentration and internal agent concentration. These parameters strongly influence the percentage removal of phenol and emulsion leakage. Under optimum membrane properties, the percentage removal of phenol was as high as 98.33%, with emulsion leakage of 1.25%. It was also found that the necessity of carrier for enhancing phenol removal was strongly dependent on the internal agent concentration.

  3. Mathematical Approach in Rheological Characterizing of Asphalt Emulsion Residues

    Directory of Open Access Journals (Sweden)

    Seong Hwan Cho

    2015-01-01

    Full Text Available Three different emulsion residues, such as SS1HP, HFE90, and SS-1VH (trackless, and a base asphalt binder (PG 64-22 are compared to characterize rheological properties by using DSR test. In order to capture the emulsion properties, different frequencies (from 1 to 100 rad/sec at a 10% constant shear rate and temperatures (from −45°C to 75°C with 15°C increments were applied. Then, a master curve for shear modulus was plotted for each emulsion. The transition of the HFE90 emulsion from viscous to elastic behavior occurs at lower temperatures, compared to the other materials. This emulsion is known for performing in a wider temperature range as shown in the results. The trackless emulsion presents an elastic behavior at intermediate temperatures. This product is known as having very fast setting and high resistance to shear stresses. The trackless emulsion presents the highest viscous and elastic modulus, followed by the PG 64-22 binder, SS1HP, and HFE90 emulsion. Shear strength test results show a behavior between trackless emulsion and SS1HP similar to the frequency sweep test results performed by DSR.

  4. Living olefin polymerization processes

    Science.gov (United States)

    Schrock, Richard R.; Baumann, Robert

    1999-01-01

    Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

  5. Phosphazene-promoted anionic polymerization

    KAUST Repository

    Zhao, Junpeng

    2014-01-01

    In the recent surge of metal-free polymerization techniques, phosphazene bases have shown their remarkable potential as organic promoters/catalysts for the anionic polymerization of various types of monomers. By complexation with the counterion (e.g. proton or lithium cation), phosphazene base significantly improve the nucleophilicity of the initiator/chain-end resulting in rapid and usually controlled anionic/quasi-anionic polymerization. In this review, we will introduce the general mechanism, i.e. in situ activation (of initiating sites) and polymerization, and summarize the applications of such a mechanism on macromolecular engineering toward functionalized polymers, block copolymers and complex macromolecular architectures.

  6. Inflatable Elastomeric Macroporous Polymers Synthesized from Medium Internal Phase Emulsion Templates.

    Science.gov (United States)

    Tebboth, Michael; Jiang, Qixiang; Kogelbauer, Andreas; Bismarck, Alexander

    2015-09-02

    Closed cell elastomeric polydimethylsiloxane (PDMS) based polymerized medium internal phase emulsions (polyMIPEs) containing an aqueous solution of sodium hydrogen carbonate (NaHCO3) have been produced. Via thermal decomposition of NaHCO3, carbon dioxide was released into the polyMIPE structure to act as a blowing agent. When placed into an atmosphere with reduced pressure, these macroporous elastomers expanded to many times their original size, with a maximum expansion of 30 times. This expansion was found to be repeatable and reproducible. The extent of volume expansion was determined primarily by the dispersed phase volume ratio of the emulsion template; polyMIPEs with 60% dispersed phase content produced greater volume expansion ratios than polyMIPEs with 50% dispersed phase. Increasing the concentration of NaHCO3 in the dispersed phase also led to increased expansion due to the greater volume of gas forming within the porous structure of the silicone elastomer. The expansion ratio could be increased by doubling the agitation time during the emulsification process to form the MIPEs, as this decreased the pore wall thickness and hence the elastic restoring force of the porous silicone elastomer. Although MIPEs with 70% dispersed phase could be stabilized and successfully cured, the resultant polyMIPE was mechanically too weak and expanded less than polyMIPEs with a dispersed phase of 60%. It was also possible to cast the liquid emulsion into thin polyMIPE films, which could be expanded in vacuum, demonstrating that these materials have potential for use in self-sealing containers.

  7. Facile fabrication of biocompatible PLGA drug-carrying microspheres by O/W pickering emulsions.

    Science.gov (United States)

    Wei, Zengjiang; Wang, Chaoyang; Liu, Hao; Zou, Shengwen; Tong, Zhen

    2012-03-01

    This study is focused on the preparation of Ibuprofen (IBU) loaded micrometer-sized poly(lactic-co-glycolic acid) (PLGA) microspheres and process variables on the size, drug loading and release during preparation of formulation. Silicon dioxide (SiO(2)) nanoparticle-coated PLGA microspheres were fabricated via a combined system of "Pickering-type" emulsion route and solvent volatilization method in the absence of any molecular surfactants. Stable oil-in-water emulsions were prepared using SiO(2) nanoparticles as a particulate emulsifier and a dichloromethane (CH(2)Cl(2)) solution of PLGA as an oil phase. The SiO(2) nanoparticle-coated PLGA microspheres were fabricated by the evaporation of CH(2)Cl(2) in situ, and then bare-PLGA microspheres were prepared by removal of the SiO(2) nanoparticles using HF aqueous solution. The two types of microspheres were characterized in terms of size, component and morphology using scanning electronic microscope (SEM), Fourier-transform infrared, optical microscope, and so on. Moreover, IBU was encapsulated into the hybrid beads by dispersing them in the CH(2)Cl(2) solution of PLGA in the fabrication process. The sustained release could be obtained due to the barrier of the polymeric matrix (PLGA). More over, the release curves were nicely fitted by the Weibull equation and the release followed Fickian diffusion. The combined system of Pickering emulsion and solvent volatilization opens up a new route to fabricate a variety of microspheres. The resulting microspheres may find applications as delivery vehicles for biomolecules, drugs, cosmetics and living cells. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Research progress of Pickering emulsions%Pickering乳液研究进展

    Institute of Scientific and Technical Information of China (English)

    刘悦; 陈朝霞; 段兰兰; 张玉红

    2014-01-01

    Pickering emulsifiers are the solid particles emulsifiers instead of the surfactant moleculars which are adsorbed at the oil-water interface and used as the robust barrier to prevent the aggregation of monomer droplets. In recent years,the Pickering emulsions have attracted increasing interest due to their widely application prospects in various fields, especially in the paper, emulsion polymerization, cosmetics, drug release and preparation of functional polymer. In this paper,the mechanism of Pickering emulsifier, emulsifiering stability factors, phase inversion and application aspects were summarized in details.%Pickering乳化剂是指用固体颗粒代替传统的化学乳化剂,固体颗粒在分散相液滴表面形成一层薄膜阻止了液滴之间的聚集,在造纸、乳液聚合、化妆品、药物缓释和制备功能高分子领域具有应用前景。本文从Pickering乳化剂的作用机理、乳化稳定因素、相转化以及应用几个方面进行总结。

  9. High internal ionic liquid phase emulsion stabilized by metal-organic frameworks.

    Science.gov (United States)

    Li, Zhihao; Zhang, Jianling; Luo, Tian; Tan, Xiuniang; Liu, Chengcheng; Sang, Xinxin; Ma, Xue; Han, Buxing; Yang, Guanying

    2016-11-04

    The emulsification of metal-organic frameworks (MOFs) for the two immiscible phases of water and ionic liquid (IL) was investigated for the first time. It was found that Ni-BDC (BDC = 1,4-dicarboxybenzene) can emulsify water and ILs and favor the formation of high internal phase emulsions (HIPEs) under certain experimental conditions. The microstructures of the HIPEs were characterized by confocal laser scanning microscopy using a fluorescent dye Rhodamine B, which proves that the HIPEs are the IL-in-water type. Further results reveal that the HIPE forms during the IL-in-water to water-in-IL emulsion inversion. The possibilities of the HIPE formation by other MOFs (Cu-BDC and Zn-BDC) were explored and the mechanism for HIPE formation was discussed. The MOF-stabilized HIPE was applied to the in situ synthesis of a MOF/polymer composite by HIPE polymerization. The macroporous MOF/polyacrylamide network and MOF/polystyrene microspheres were obtained from the HIPEs, respectively.

  10. Emulsion preparation for novel micro-porous polymeric hemi-shells

    CSIR Research Space (South Africa)

    Naidoo, Kersch

    2008-01-01

    Full Text Available -dichloromethane (DCM) oil phase and emulsification in an acidic polyvinyl alcohol (PVA) aqueous phase, micro-porous hemi-shells formed as solvent evaporated. CO2 gas evolution from the porogen created particles with an externally micro-porous shell and a large internal...

  11. Growth Kinetics of Monodisperse Polystyrene Microspheres Prepared by Dispersion Polymerization

    Directory of Open Access Journals (Sweden)

    Fan Li

    2013-01-01

    Full Text Available Dispersion polymerization has been widely applied to the synthesis of monodisperse micron-sized polymer colloidal spheres. Many efforts have been devoted to studying the influence of initial conditions on the size and uniformity of the resultant microspheres, aiming to synthesize micron-size monodisperse colloidal spheres. However, the inner contradiction between the size and the size distribution of colloidal spheres hinders the realization of this goal. In this work, we drew our attention from the initial conditions to the growth stage of dispersion polymerization. We tracked the size evolution of colloidal sphere during the dispersion polymerization, through which we established a kinetic model that described the relationship between the monomer concentration and the reaction time. The model may provide a guideline to prepare large polymer colloidal spheres with good monodispersity by continuous monomer feeding during the growth stage to maintain the concentration of monomer at a constant value in a dispersion polymerization process.

  12. Gratings in polymeric waveguides

    Science.gov (United States)

    Mishakov, G.; Sokolov, V.; Kocabas, A.; Aydinli, A.

    2007-04-01

    Laser-induced formation of polymer Bragg grating filters for Dense Wavelength Division Multiplexing (DWDM) applications is discussed. Acrylate monomers halogenated with both fluorine and chlorine, which possess absorption losses less than 0.25 dB/cm and wide choice of refractive indices (from 1.3 to 1.5) in the 1.5 μm telecom wavelength region were used. The monomers are highly intermixable thus permitting to adjust the refractive index of the composition within +/-0.0001. Moreover they are photocurable under UV exposure and exhibit high contrast in polymerization. These properties make halogenated acrylates very promising for fabricating polymeric waveguides and photonic circuits. Single-mode polymer waveguides were fabricated on silicon wafers using resistless contact lithography. Submicron index gratings have been written in polymer waveguides using holographic exposure with He-Cd laser beam (325 nm) through a phase mask. Both uniform and apodized gratings have been fabricated. The gratings are stable and are not erased by uniform UV exposure. The waveguide gratings possess narrowband reflection spectra in the 1.5 μm wavelength region of 0.4 nm width, nearly rectangular shape of the stopband and reflectivity R > 99%. The fabricated Bragg grating filters can be used for multiplexing/demultiplexing optical signals in high-speed DWDM optical fiber networks.

  13. Surrogate Models for Online Monitoring and Process Troubleshooting of NBR Emulsion Copolymerization

    Directory of Open Access Journals (Sweden)

    Chandra Mouli R. Madhuranthakam

    2016-03-01

    Full Text Available Chemical processes with complex reaction mechanisms generally lead to dynamic models which, while beneficial for predicting and capturing the detailed process behavior, are not readily amenable for direct use in online applications related to process operation, optimisation, control, and troubleshooting. Surrogate models can help overcome this problem. In this research article, the first part focuses on obtaining surrogate models for emulsion copolymerization of nitrile butadiene rubber (NBR, which is usually produced in a train of continuous stirred tank reactors. The predictions and/or profiles for several performance characteristics such as conversion, number of polymer particles, copolymer composition, and weight-average molecular weight, obtained using surrogate models are compared with those obtained using the detailed mechanistic model. In the second part of this article, optimal flow profiles based on dynamic optimisation using the surrogate models are obtained for the production of NBR emulsions with the objective of minimising the off-specification product generated during grade transitions.

  14. Janus emulsions formed with a polymerizable monomer, silicone oil, and Tween 80 aqueous solution.

    Science.gov (United States)

    Ge, Lingling; Lu, Shuhui; Guo, Rong

    2014-06-01

    Janus emulsions of a polymerizable monomer tripropyleneglycol diacrylate (TP) combined with silicone oil (SO) as inner oil phases and Tween 80 aqueous solution as continuous phase are prepared in a one-step high energy mixing process. The dependence of droplet topology on the concentration of surfactant, TP/SO ratio, and the stirring speed during emulsification is investigated. The result shows that the volume ratio of two oils within an individual droplet changes correspondingly to the total composition of emulsion. Increasing the speed of stirring results in a significant reduction in the droplet size, i.e. a five times increase in the stirring speed produces a droplet size reduction from hundreds to a few microns. What is more important, the topology of Janus drops remains similar for the different preparations. These fundamental investigations illustrate the potential for future Janus particle synthesis in batch scale with a controllable particle topology.

  15. Mechanistic study on demulsification of water-in-diluted bitumen emulsions by ethylcellulose.

    Science.gov (United States)

    Feng, Xianhua; Mussone, Paolo; Gao, Song; Wang, Shengqun; Wu, Shiau-Yin; Masliyah, Jacob H; Xu, Zhenghe

    2010-03-02

    In our previous study, ethylcellulose (EC), an effective, nontoxic, and biodegradable natural polymer, was found effective in dewatering water-in-diluted bitumen emulsions. In this study, the demulsification mechanism of water-in-diluted bitumen emulsions by EC is investigated. In situ experiments using a micropipet apparatus provided direct evidence on both flocculation and coalescence of water droplets in diluted bitumen by EC. The addition of EC was found to decrease naphtha-diluted bitumen-water interfacial tension significantly. At the molecular level, AFM imaging revealed disruption of the continuous interfacial films formed from surface-active components of bitumen by EC. Our study clearly indicates that the demulsification by EC is through both flocculation and coalescence of water droplets, attained by competitive adsorption of EC at the oil-water interface and disruption of the original protective interfacial films formed from the surface-active components of bitumen.

  16. Textural perception of liquid emulsions: Role of oil content, oil viscosity and emulsion viscosity

    NARCIS (Netherlands)

    Aken, van G.A.; Vingerhoeds, M.H.; Wijk, de R.A.

    2011-01-01

    This work describes a study on the in-mouth textural perception of thickened liquid oil-in-water emulsions. The variables studied are oil content, oil viscosity, and the concentration of polysaccharide thickener. Gum arabic was chosen as the thickener because of the nearly Newtonian behavior of its

  17. Colloidal and micro-carbon spheres derived from low-temperature polymerization reactions.

    Science.gov (United States)

    Moreno-Castilla, Carlos

    2016-10-01

    Carbon spheres (CSs) have recently attracted major interest due to their new applications, mainly in energy storage and conversion but also in hard-templating, sorption/catalysis processes, and drug delivery systems. This is attributable to their physico-chemical properties, including their tunable morphology (solid, hollow and core-shell), size, surface area/porosity, good electrical conductivity, low external surface-to-volume ratio, high packing density, enhanced mass transport, robust mechanical stability, low cytotoxicity, and excellent biocompatibility. They can be obtained from a wide variety of carbon precursors and methods. This review covers their production by carbonization of polymer spheres from low-temperature polymerization reactions, considered here as below 250°C. This is a very important method because it allows the synthesis of CSs with different morphologies and doped with other elements or chemical compounds. The preparation of polymer spheres by this technique is well documented in the literature, and the objective of this review is to summarize and give an overview of the most significant publications, proposing a novel classification based on the formation mechanism of the polymer spheres. This classification includes the following polymerization processes: emulsion polymerization and its derivatives, seeded emulsion and inverse emulsion polymerization; precipitation polymerization and its derivative, dispersion polymerization; hard-templating; spray-drying; and hydrothermal or solvothermal treatment of carbohydrates and biomass in general. This review also reports on the morphology and surface characteristics of the CSs obtained by different synthetic approaches. The final section of the review describes the current applications of these CSs, notably in energy storage (supercapacitors and rechargeable batteries) and energy conversion (fuel cells and dye-sensitized solar cells). Besides the numerous applications listed above, they are

  18. New techniques for emulsion analysis in a hybrid experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, K. (Aichi University of Education, Kariya 448 (Japan)); Ushida, N. (Aichi University of Education, Kariya 448 (Japan)); Mokhtarani, A. (University of California (Davis), Davis, CA 95616 (United States)); Paolone, V.S. (University of California (Davis), Davis, CA 95616 (United States)); Volk, J.T. (University of California (Davis), Davis, CA 95616 (United States)); Wilcox, J.O. (University of California (Davis), Davis, CA 95616 (United States)); Yager, P.M. (University of California (Davis), Davis, CA 95616 (United States)); Edelstein, R.M. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Freyberger, A.P. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Gibaut, D.B. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Lipton, R.J. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Nichols, W.R. (Carnegie-Mellon University, Pittsburgh, PA 15213 (United States)); Potter, D.M. (Carnegie-Mellon Univers

    1994-08-01

    A new method, called graphic scanning, was developed by the Nagoya University Group for emulsion analysis in a hybrid experiment. This method enhances both speed and reliability of emulsion analysis. Details of the application of this technique to the analysis of Fermilab experiment E653 are described. ((orig.))

  19. Synthesis of metallic nanoshells on porphyrin-stabilized emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haorong (Albuquerque, NM); Song, Yujiang (Albuquerque, NM); Shelnutt, John A. (Tijeras, NM); Medforth, Craig J. (Winters, CA)

    2011-12-13

    Metal nanostructures formed by photocatalytic interfacial synthesis using a porphyrin-stabilized emulsion template and the method for making the nanostructures. Catalyst-seeded emulsion droplets are employed as templates for hollow-nanoshell growth. The hollow metal nanospheres may be formed with or without inclusions of other materials.

  20. Emulsion Preparation with Micro-Structured Systems (online)

    NARCIS (Netherlands)

    Schroën, C.G.P.H.; Sahin, S.; Dijke, van K.C.; Graaf, van der S.; Zijffers, J.F.; Krebs, T.; Boom, R.M.

    2014-01-01

    Microfluidic devices can be used for either pre-mix emulsification (a method in which a coarse emulsion is broken up by passing it through a geometry) or direct emulsification (a method in which oil and water are introduced separately in the device and the emulsion is formed at their point of contac

  1. Pickering Emulsions for Food Applications: Background, Trends, and Challenges

    NARCIS (Netherlands)

    Berton-Carabin, C.C.; Schroën, C.G.P.H.

    2015-01-01

    Particle-stabilized emulsions, also referred to as Pickering emulsions, have garnered exponentially increasing interest in recent years. This has also led to the first food applications, although the number of related publications is still rather low. The involved stabilization mechanisms are fundam

  2. Interplay between Colloids and Interfaces : Emulsions, Foams and Microtubes

    NARCIS (Netherlands)

    de Folter, J.W.J.

    2013-01-01

    The central theme of this thesis is the interplay between colloids and interfaces. The adsorption of colloids at fluid-fluid interfaces is the main topic and covers Chapters 2-6. Pickering emulsions where colloidal particles act as emulsion stabilizers in the absence of surfactants are studied in a

  3. Water-in-diesel emulsions and related systems.

    Science.gov (United States)

    Lif, Anna; Holmberg, Krister

    2006-11-16

    Water-in-diesel emulsions are fuels for regular diesel engines. The advantages of an emulsion fuel are reductions in the emissions of nitrogen oxides and particulate matters, which are both health hazardous, and reduction in fuel consumption due to better burning efficiency. An important aspect is that diesel emulsions can be used without engine modifications. This review presents the influence of water on the emissions and on the combustion efficiency. Whereas there is a decrease in emissions of nitrogen oxides and particulate matters, there is an increase in the emissions of hydrocarbons and carbon monoxide with increasing water content of the emulsion. The combustion efficiency is improved when water is emulsified with diesel. This is a consequence of the microexplosions, which facilitate atomization of the fuel. The review also covers related fuels, such as diesel-in-water-in-diesel emulsions, i.e., double emulsions, water-in-diesel microemulsions, and water-in-vegetable oil emulsions, i.e., biodiesel emulsions. A brief overview of other types of alternative fuels is also included.

  4. Tocopherol isoforms in parenteral lipid emulsions and neutrophil activation.

    NARCIS (Netherlands)

    Wanten, G.J.A.; Beunk, J.; Naber, A.H.J.; Swinkels, D.W.

    2002-01-01

    BACKGROUND AND AIMS: Tocopherol is a lipid-soluble anti-oxidant that exists in several isoforms. Patients on total parenteral nutrition depend on lipid emulsions for their tocopherol intake. In the present study, we analysed the content of tocopherol isoforms in various lipid emulsions. We also

  5. Oxidative Stability and Shelf Life of Food Emulsions

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte

    2016-01-01

    Lipid oxidation and antioxidant effects in food emulsions are influenced by many different factors, such as the composition of the aqueous phase and interface, the partitioning of the antioxidants between the different phases of the emulsion system, the antioxidant properties, and others. This ch...

  6. Cosmetic emulsion from virgin olive oil: Formulation and bio ...

    African Journals Online (AJOL)

    Cosmetic emulsion from virgin olive oil: Formulation and bio-physical ... virgin olive oil was developed by entrapping it in the oily phase of oil-in-water (o/w) emulsion. ... The evaluation parameters consisted of color, smell, phase separation, ...

  7. Preparation of double emulsions by membrane emulsification - a review

    NARCIS (Netherlands)

    Graaf, van der S.; Schroën, C.G.P.H.; Boom, R.M.

    2005-01-01

    Double emulsions have potential for the production of low calorie food products, encapsulation of medicines and other high value products. The main issue is the difficulty to efficiently produce double emulsions in a well controlled manner due to their shear sensitivity. In membrane emulsification o

  8. Pickering Emulsions for Food Applications: Background, Trends, and Challenges

    NARCIS (Netherlands)

    Berton-Carabin, C.C.; Schroën, C.G.P.H.

    2015-01-01

    Particle-stabilized emulsions, also referred to as Pickering emulsions, have garnered exponentially increasing interest in recent years. This has also led to the first food applications, although the number of related publications is still rather low. The involved stabilization mechanisms are

  9. Tuning Amphiphilicity of Particles for Controllable Pickering Emulsion

    Directory of Open Access Journals (Sweden)

    Zhen Wang

    2016-11-01

    Full Text Available Pickering emulsions with the use of particles as emulsifiers have been extensively used in scientific research and industrial production due to their edge in biocompatibility and stability compared with traditional emulsions. The control over Pickering emulsion stability and type plays a significant role in these applications. Among the present methods to build controllable Pickering emulsions, tuning the amphiphilicity of particles is comparatively effective and has attracted enormous attention. In this review, we highlight some recent advances in tuning the amphiphilicity of particles for controlling the stability and type of Pickering emulsions. The amphiphilicity of three types of particles including rigid particles, soft particles, and Janus particles are tailored by means of different mechanisms and discussed here in detail. The stabilization-destabilization interconversion and phase inversion of Pickering emulsions have been successfully achieved by changing the surface properties of these particles. This article provides a comprehensive review of controllable Pickering emulsions, which is expected to stimulate inspiration for designing and preparing novel Pickering emulsions, and ultimately directing the preparation of functional materials.

  10. Electrospraying of water in oil emulsions for thin film coating

    NARCIS (Netherlands)

    Khan, M.K.I.; Maan, A.A.; Schutyser, M.A.I.; Schroën, C.G.P.H.; Boom, R.M.

    2013-01-01

    Electrospraying of water-in-oil emulsions was investigated to produce thin edible barriers. A reproducible model surface was used, namely cellulose membranes of which permeability is well-established. PGPR-based emulsions were stable during electrospraying and produced a fine stable jet spray; emuls

  11. Engineering of acidic O/W emulsions with pectin

    NARCIS (Netherlands)

    Alba, Katerina; Sagis, L.M.C.; Kontogiorgos, Vassilis

    2016-01-01

    Pectins with distinct molecular design were isolated by aqueous extraction at pH 2.0 or 6.0 and were examined in terms of their formation and stabilisation capacity of model n-alkane–in–water emulsions at acidic pH (pH 2.0). The properties and stability of the resulting emulsions were examined by me

  12. Formulation of indomethacin emulsion using biopolymer of Prunus avium.

    Science.gov (United States)

    Verma, Shivangi; Dabral, Prashant; Rana, Vinod; Upadhaya, Kumud; Bhardwaj

    2012-03-01

    The aim of the investigation was to formulate Indomethacin Emulsion using Bio-polymer as Emulsifier. Different batches of emulsions were prepared by varying concentration of biopolymer prunus avium. Based evaluation of the prepared polymers, a conclusion can be drawn that in the Prunus avium bio-material can serve as a promising film forming agent for formulating various drug.

  13. Formulation of indomethacin emulsion using biopolymer of Prunus avium

    Directory of Open Access Journals (Sweden)

    Shivangi Verma

    2012-01-01

    Full Text Available The aim of the investigation was to formulate Indomethacin Emulsion using Bio-polymer as Emulsifier. Different batches of emulsions were prepared by varying concentration of biopolymer prunus avium. Based evaluation of the prepared polymers, a conclusion can be drawn that in the Prunus avium bio-material can serve as a promising film forming agent for formulating various drug.

  14. Physical stability of caseinate stabilized emulsions during heating.

    NARCIS (Netherlands)

    Cruijsen, J.M.M.

    1996-01-01

    The physical stability of caseinate stabilized emulsions was studied during heating (80- 120°C). Coagulation, coalescence and phase separation of the caseinate emulsions was studied using objective heat stability tests. The physical changes were characterized by light microscopy, particle size measu

  15. Synthesis of metallic nanoshells on porphyrin-stabilized emulsions

    Science.gov (United States)

    Wang, Haorong [Albuquerque, NM; Song, Yujiang [Albuquerque, NM; Shelnutt, John A [Tijeras, NM; Medforth, Craig J [Winters, CA

    2011-12-13

    Metal nanostructures formed by photocatalytic interfacial synthesis using a porphyrin-stabilized emulsion template and the method for making the nanostructures. Catalyst-seeded emulsion droplets are employed as templates for hollow-nanoshell growth. The hollow metal nanospheres may be formed with or without inclusions of other materials.

  16. Multi-responsive ionic liquid emulsions stabilized by microgels

    NARCIS (Netherlands)

    Monteillet, H.J.M.; Workamp, M.J.; Li, X.; Schuur, B.; Kleijn, J.M.; Leermakers, F.A.M.; Sprakel, J.H.B.

    2014-01-01

    We present a complete toolbox to use responsive ionic liquid (IL) emulsions for extraction purposes. IL emulsions stabilized by responsive microgels are shown to allow rapid extraction and reversible breaking and re-emulsification. Moreover, by using a paramagnetic ionic liquid, droplets can be easi

  17. Microfluidic production of multiple emulsions and functional microcapsules

    NARCIS (Netherlands)

    Lee, Tae Yong; Choi, Tae Min; Shim, Tae Soup; Frijns, Raoul A.M.; Kim, Shin Hyun

    2016-01-01

    Recent advances in microfluidics have enabled the controlled production of multiple-emulsion drops with onion-like topology. The multiple-emulsion drops possess an intrinsic core–shell geometry, which makes them useful as templates to create microcapsules with a solid membrane. High flexibility in t

  18. Influence of the ratio of amphiphilic copolymers used as emulsifiers on the microstructure, physical stability and rheology of α-pinene emulsions stabilized with gellan gum.

    Science.gov (United States)

    García, Maria Carmen; Alfaro, Maria Carmen; Muñoz, José

    2015-11-01

    α-Pinene is a terpenic solvent whose use in the formulation of emulsions entails a double benefit from the environmental point of view since it is a green solvent, easily biodegradable, which also has certain antimicrobial properties. In this work a combination of Atlas™ G-5000 and Atlox™ 4913 amphiphilic copolymers was used to obtain O/W emulsions formulated with α-pinene and gellan gum. These emulsions may find applications related to the design of complex biotechnological systems with different uses. In order to investigate the microstructure and the physical stability of these emulsions, a combination of different techniques such as rheology, microscopy, laser diffraction and multiple light scattering turn out to be a useful methodology. The results demonstrated the need to include a minimum amount of Atlas™ G-5000 copolymer in the formulation of these emulsions to improve their stability. These results were supported by the information revealed by optical micrographs, according to which Atlas™ G-5000 is directed to the continuous medium to structure water (this surfactant is particularly effective at forming hydrogen bonds with water). On the other hand Atlox™ 4913 is preferentially adsorbed at the α-pinene-water interface, such that a high Atlox™ 4913/Atlas™ G-5000 mass ratio slows down the kinetics of coalescence as shown by multiple light scattering. However, a very low relative concentration of Atlas™ G-5000 causes creaming to become the dominant destabilization mechanism. Increasing the Atlas™ G-5000/Atlox™ 4913 mass ratio yields emulsions with enhanced viscosity and viscoelasticity.

  19. Polymeric lithography editor: Editing lithographic errors with nanoporous polymeric probes.

    Science.gov (United States)

    Rajasekaran, Pradeep Ramiah; Zhou, Chuanhong; Dasari, Mallika; Voss, Kay-Obbe; Trautmann, Christina; Kohli, Punit

    2017-06-01

    A new lithographic editing system with an ability to erase and rectify errors in microscale with real-time optical feedback is demonstrated. The erasing probe is a conically shaped hydrogel (tip size, ca. 500 nm) template-synthesized from track-etched conical glass wafers. The "nanosponge" hydrogel probe "erases" patterns by hydrating and absorbing molecules into a porous hydrogel matrix via diffusion analogous to a wet sponge. The presence of an interfacial liquid water layer between the hydrogel tip and the substrate during erasing enables frictionless, uninterrupted translation of the eraser on the substrate. The erasing capacity of the hydrogel is extremely high because of the large free volume of the hydrogel matrix. The fast frictionless translocation and interfacial hydration resulted in an extremely high erasing rate (~785 μm(2)/s), which is two to three orders of magnitude higher in comparison with the atomic force microscopy-based erasing (~0.1 μm(2)/s) experiments. The high precision and accuracy of the polymeric lithography editor (PLE) system stemmed from coupling piezoelectric actuators to an inverted optical microscope. Subsequently after erasing the patterns using agarose erasers, a polydimethylsiloxane probe fabricated from the same conical track-etched template was used to precisely redeposit molecules of interest at the erased spots. PLE also provides a continuous optical feedback throughout the entire molecular editing process-writing, erasing, and rewriting. To demonstrate its potential in device fabrication, we used PLE to electrochemically erase metallic copper thin film, forming an interdigitated array of microelectrodes for the fabrication of a functional microphotodetector device. High-throughput dot and line erasing, writing with the conical "wet nanosponge," and continuous optical feedback make PLE complementary to the existing catalog of nanolithographic/microlithographic and three-dimensional printing techniques. This new PLE

  20. Destruction of secondary water-oil emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Abashev, R.G.; Isayev, M.G.; Nikolayeva, T.M.; Zheryakova, N.I.

    1984-01-01

    The article advances a number of requirements for the object, methods and means of destroying secondary water-oil emulsions (WOE) which currently cannot be recovered. By using the latest advances in science: chemistry of oil and surfactants, physicochemical surface phenomena, physical mechanics of dispersed systems, hydrodynamics and engineering chemistry jointly with the fundamentals of economics, efficient solutions are indicated for stabilization of the composition and property of WOE, and their destruction in a stationary technological process. A flowsheet is established for the recommended technology.

  1. Detecting Double Beta Decays Using Nuclear Emulsions

    CERN Document Server

    Dracos, Marcos

    2008-01-01

    Neutrino nature and absolute mass scale are major questions in particle physics which cannot be addressed by the present neutrino oscillation program. To answer these two questions, several neutrinoless double beta decay experiments are underway or planed for the near future. These experiments, mainly use bolometric techniques or gaseous counters coupled with scintillator detectors. The energy resolution is better in bolometric experiments but experiments coupling tracking with calorimetry have the advantage of observing the two electron tracks and remove many background sources. Here, we present a proposal of using nuclear emulsions to observe double beta decays. This technique has the advantage of precise tracking and vertexing even for low energy electrons.

  2. Synthesis of Core-shell Polyacrylate Emulsion and Its Thermal Stability%核壳结构聚丙烯酸酯乳液的合成及其热稳定性

    Institute of Scientific and Technical Information of China (English)

    侯炜; 朱岩; 李琰

    2011-01-01

    Polyacrylate emulsion with "hard-soft-hard" structure was synthesized by a three-step core-shell emulsion polymerization technology from mixture monomer of methyl methacrylate and butyl acrylate. The thermal stability of the polyacrylate emulsion was investigated by TGA.%采用核壳乳液聚合法,以甲基丙烯酸甲酯/丙烯酸丁酯为混合单体,经三个阶段的乳液聚合反应合成了具有"硬-软-硬"结构的聚丙烯酸酯乳液.采用热重分析仪研究了其热稳定性.

  3. 阳离子醚化改性聚乙烯醇干强剂的合成及应用%Preparation and Application of Styrene-acrylic Emulsion Modified by Cationic-etherified PVA as a Dry Strength Additive

    Institute of Scientific and Technical Information of China (English)

    曹辉波; 肖舒; 何静

    2012-01-01

    With poly (vinyl alcohol) (PVA) , styrene (St) , ethyl acrylate (BA) , and acrylamide (AM)as main monomers, hydroxy propyl methacrylate ( HPMA) as functional monomer, methacroylcholine chloride ( DMC) as cationic-functional monomer, and glycidyl-trimethyl-ammonium chloride ( GTMAC) as cationic etherifying agent, the dry strength additive was prepared by semi-continuous emulsifier-free emulsion polymerization technique. The morphology of the emulsion particles and the treated paper were characterized by transmission electron microscopy and scanning electron microscopy. The result indicated that the Zeta potential of the emulsion has maximum and the dispersion system would be more stable when the dosage of DMC was 1. 5% on the whole monomers. When the amount of GTMAC was 1. 5% , the increase of dry strength was 24. 7% and folding endurance was 36 times. When the amount of HPMA was 1. 5% ~ 2. 0% on the whole monomers , the paper possessed higher dry tensile strength and folding endurance.%以聚乙烯醇(PVA)、苯乙烯(St)、丙烯酸丁酯(BA)、丙烯酰胺(AM)为基础单体,甲基丙烯酸羟丙酯(HPMA)为功能单体,甲基丙烯酰氧乙基三甲基氯化铵(DMC)为阳离子功能单体,2,3-环氧丙基三甲基氯化铵(GTMAC)为阳离子醚化剂,采用无皂乳液聚合法合成了阳离子醚化改性聚乙烯醇干强剂乳液;通过透射电镜(TEM)和扫描电镜(SEM)分别对干强剂乳液颗粒形态和纸张纤维形态进行表征和检测.结果表明,当HPMA用量为1.5%(对单体总质量而言,下同)时,干强剂乳液Zeta电位最大,体系较稳定;当GTMAC用量为1.5%时,纸张抗张强度的增幅为24.7%,耐折度的增幅为157%;当HPMA用量为1.5%~2.0%时,纸张的抗张强度和耐折度均较高.

  4. Domain and droplet sizes in emulsions stabilized by colloidal particles

    Science.gov (United States)

    Frijters, Stefan; Günther, Florian; Harting, Jens

    2014-10-01

    Particle-stabilized emulsions are commonly used in various industrial applications. These emulsions can present in different forms, such as Pickering emulsions or bijels, which can be distinguished by their different topologies and rheology. We numerically investigate the effect of the volume fraction and the uniform wettability of the stabilizing spherical particles in mixtures of two fluids. For this, we use the well-established three-dimensional lattice Boltzmann method, extended to allow for the added colloidal particles with non-neutral wetting properties. We obtain data on the domain sizes in the emulsions by using both structure functions and the Hoshen-Kopelman (HK) algorithm, and we demonstrate that both methods have their own (dis)advantages. We confirm an inverse dependence between the concentration of particles and the average radius of the stabilized droplets. Furthermore, we demonstrate the effect of particles detaching from interfaces on the emulsion properties and domain-size measurements.

  5. Lipid oxidation in omega-3 emulsions prepared with milk proteins

    DEFF Research Database (Denmark)

    Horn, Anna Frisenfeldt; Nielsen, Nina Skall; Andersen, Ulf

    components. In these three studies different parameters that are expected to change the properties and structure of the proteins at the interface were investigated. The first study compares 70% emulsions with either sodium caseinate or whey protein isolate at two pH values with and without iron addition....... The properties of the emulsifier used and the structure at the interface are therefore expected to be of great importance for oxidation in emulsions. This presentation will include results from mainly three different studies of lipid oxidation in omega-3 emulsions prepared with milk proteins and protein....... The second study evaluates the effect of two different high pressure homogenizers on oxidation in 10% emulsions with the same emulsifiers as in the first study. Finally, the third study considers the effect of changing pH on oxidation in emulsions prepared with different whey protein components. Results...

  6. Progression of radical reactions on microscopic scale in food emulsions

    DEFF Research Database (Denmark)

    Raudsepp, Piret

    Understanding the progression of lipid oxidation in oil-in-water emulsions from the aspect of the food quality and safety, consumer satisfaction and cleaner food label is of importance, because most of the food emulsions are oil-in-water emulsions. There is an increasing tendency in the food...... industry to incorporate unsaturated oils into food products, but that results in shortened shelf-life. Therefore, studying the factors and consequences of the oxidative instability provides beneficial insight into prolonging the antioxidative stage and inhibiting undergoing oxidation processes to improve...... the food quality and increase the shelflife of the food products. In the present work, lipid oxidation in oil-in-water emulsions was studied via conventional analytical and via novel state-of-the-art techniques. For the first time, the effect of mixing emulsions made of saturated medium-chain triglyceride...

  7. A Simple and Effective Test Method of the Emulsion Stability

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An innovational test method was developed on the basis of redefinition of the emulsion stability. The stability was characterized by relative volume percentage of disperse phase demulsified thoroughly from the top part and the bottom part of an emulsion sample, each weighting the same amount, after being settled for a given time at constant temperature. Three series of emulsions were prepared and tested successfully, which were emulsions of paraffin oil and water stabilized with polyoxyethylene lauryl ether series (AEO3 and AEO9) at various HLBs, and emulsions of rapeseed oil and water stablized with sorbitan monoleate (Span80) and each of polyoxyethylene (20) sorbitan carboxylic esters (Tween20, Tween40, Tween60, Tween80 and Tween85) at different HLBs. It proved that this method is especially workable while the boundaries are opaque in a wide range of HLBs and is capable of offering an accurate optimum HLB.

  8. Use of Bitumen Emulsion for Flexible Road Construction

    Directory of Open Access Journals (Sweden)

    Shivani Singh Dhriyan

    2017-02-01

    Full Text Available In the present study bitumen is replaced by bitumen emulsion for the construction of flexible pavement. The conventional method of road construction involves the burning of bitumen which produces toxic gases which degrades the environment. In colder region it is difficult to maintain the paving temperature of hot mix. To overcome these problems and conserve the energy bitumen emulsion is considered as good option. Likewise emulsion can be used in the areas having higher rate of rainfall where the hot mix plant is closed most of the time because of rain. Emulsified bitumen can be used during rainy season and colder regions. To study the suitability of emulsion Marshal Test is carried out to find the stability value, flow value and optimum binder content. Experiments performed shows that bitumen emulsion (Cold Mix have high stability value therefore it can be used as binder.

  9. Emulsion chamber experiments; critical comments and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Tamada, M. [School of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan)

    2006-01-15

    Emulsion chamber data give valuable information about particle production in the forward region of very high-energy nuclear interactions. Many characteristics of high-energy atmospheric families, observed by emulsion chambers, have not been fully described by simulations employing existing nuclear interaction models. Some of the events and the phenomena observed in emulsion chamber experiments have been considered to be unusual and new, never seen in lower energy accelerator experiments. We re-examine emulsion chamber data critically in order to get unbiased views of these unusual events and phenomena. It is shown that some of the previous interpretations need to be changed. We take up for the discussions scaling violation in C-jets, Centauro events, alignment of showers in high-energy families, hadrons of anomalous absorption in thick lead chambers. We will also discuss the results on the hybrid experiments of emulsion chamber and EAS-array.

  10. Progression of radical reactions on microscopic scale in food emulsions

    DEFF Research Database (Denmark)

    Raudsepp, Piret

    Understanding the progression of lipid oxidation in oil-in-water emulsions from the aspect of the food quality and safety, consumer satisfaction and cleaner food label is of importance, because most of the food emulsions are oil-in-water emulsions. There is an increasing tendency in the food...... the food quality and increase the shelflife of the food products. In the present work, lipid oxidation in oil-in-water emulsions was studied via conventional analytical and via novel state-of-the-art techniques. For the first time, the effect of mixing emulsions made of saturated medium-chain triglyceride...... industry to incorporate unsaturated oils into food products, but that results in shortened shelf-life. Therefore, studying the factors and consequences of the oxidative instability provides beneficial insight into prolonging the antioxidative stage and inhibiting undergoing oxidation processes to improve...

  11. Techniques and methods to study functional characteristics of emulsion systems

    Directory of Open Access Journals (Sweden)

    Yin-Ting Hu

    2017-01-01

    Full Text Available With the growing popularity of the functional food market, bioactive ingredients from natural sources are discovered one after another for their ability to promote better health and prevent chronic diseases. Emulsion, widely occurring in many food systems, has become a popular vehicle to facilitate the incorporation of bioactive components into the food system. Depending on the designated functionality, an emulsion can be developed with various physical and chemical properties. To ensure the successful development of a high-quality emulsion-based system to serve their purpose in food, knowledge of the analytical methods that could efficiently evaluate their quality parameters is important for investigators who work in this field. In this work, important emulsion properties are overviewed, and techniques that are commonly used to assess them are provided. Discussions and recommendations are also included to make suggestions on advantages and disadvantages when selecting suitable techniques and methods to characterize these quality parameters of emulsion systems.

  12. An exclusively based parenteral fish-oil emulsion reverses cholestasis.

    Science.gov (United States)

    Triana Junco, Miryam; García Vázquez, Natalia; Zozaya, Carlos; Ybarra Zabala, Marta; Abrams, Steven; García de Lorenzo, Abelardo; Sáenz de Pipaón Marcos, Miguel

    2014-10-25

    Prolonged parenteral nutrition (PN) leads to liver damage. Recent interest has focused on the lipid component of PN. A lipid emulsion based on w-3 fatty acids decrease conjugated bilirubin. A mixed lipid emulsion derived from soybean, coconut, olive, and fish oils reverses jaundice. Here we report the reversal of cholestasis and the improvement of enteral feeding tolerance in 1 infant with intestinal failure-associated liver disease. Treatment involved the substitution of a mixed lipid emulsion with one containing primarily omega-3 fatty acids during 37 days. Growth and biochemical tests of liver function improved significantly. This suggests that fat emulsions made from fish oils may be more effective means of treating this condition compared with an intravenous lipid emulsion containing soybean oil, medium -chain triglycerides, olive oil, and fish oil.

  13. Synthesis of a Novel Core-shell Type Acrylic-polyurethane Hybrid Emulsion Containing Siloxane and Fluorine as well as Water and the Oil Resistances of Cured Film

    Institute of Scientific and Technical Information of China (English)

    Jing CHAO; Xing Yuan ZHANG; Jia Bing DAI; Zhen GE; Lin Lin FENG

    2006-01-01

    Siliconated polyurethane (Si-PU) was synthesized using isophorone diisocyanate (IPDI), hydroxybutyl-terminated polydimethylsiloxane (PDMS), polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG), 1,6-hexanediol (HDO), dimethylol propionic acid (DMPA) and triethylamine (TEA). Based on butyl acrylate (BA), 2, 2, 2-trifluoroethylmethacrylate (TFEMA) and Si-PU as a seed emulsion, a novel core-shell type acrylic-polyurethane hybrid emulsion, containing siloxane and fluorine (F-Si-PU), was prepared by seeded emulsion polymerization. The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy (FTIR) was used to identify the chain structures of Si-PU and F-Si-PU. Investigation of transmission electron microscopy (TEM) confirmed the core-shell structure of F-Si-PU emulsion. Measurement results of water contact angle and the swelling ratio in water and n-octane for cured film showed that the water and the oil resistances for F-Si-PU had been significantly improved at a suitable content of fluorine and siloxane.

  14. Effect of Emulsifier on the Stability of Emulsion Explosives%复合乳化剂对乳化炸药稳定性的影响研究

    Institute of Scientific and Technical Information of China (English)

    殷雅婷; 刘勇; 葛茜云

    2014-01-01

    将Span-80与高分子乳化剂按一定比例配制成复合乳化剂,利用复合乳化剂制得复合油相用于生产乳化炸药。通过高低温试验与爆速、猛度相结合的方法,对不同类型的复合乳化剂的乳化炸药进行了稳定性的研究。结果表明,采用我厂自合的M型复合乳化剂可制备出储存稳定性好的乳化炸药,同时也表明复合乳化剂对于提高乳化炸药的稳定性作用明显优于单一乳化剂。%The Span-80 and polymeric emulsifier were prepared emulsifier by a certain percentage , using emulsifier obtained compound oil for the production of emulsion explosives.Through the high and low temperature test and detonation velocity Brisance method of combining , the different types of emulsion explosive emulsifier were studied.The results showed that adoption self -closing M -type emulsifier , good storage stability can be prepared by emulsion explosives , simultaneously , and the emulsifier to improve the stability of emulsion explosives was superior to a single emulsifier.

  15. Collaborative Research: Polymeric Multiferroics

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Shenqiang [Temple Univ., Philadelphia, PA (United States). College of Engineering

    2017-04-20

    The goal of this project is to investigate room temperature magnetism and magnetoelectric coupling of polymeric multiferroics. A new family of molecular charge-transfer crystals has been emerged as a fascinating opportunity for the development of all-organic electrics and spintronics due to its weak hyperfine interaction and low spin-orbit coupling; nevertheless, direct observations of room temperature magnetic spin ordering have yet to be accomplished in organic charge-transfer solids. Furthermore, room temperature magnetoelectric coupling effect hitherto known multiferroics, is anticipated in organic donor-acceptor complexes because of magnetic field effects on charge-transfer dipoles, yet this is also unexplored. The PI seeks to fundamental understanding of the control of organic crystals to demonstrate and explore room temperature multiferroicity. The experimental results have been verified through the theoretical modeling.

  16. Synthesis and Properties of Post Cross-linked Acrylic Emulsion Pressure Sensitive Adhesive%外交联型丙烯酸酯乳液压敏胶的制备与性能

    Institute of Scientific and Technical Information of China (English)

    张蕊; 张云飞; 梁利岩; 兰延勋; 杨成华; 吕满庚

    2013-01-01

    以丙烯酸丁酯(BA)、醋酸乙烯酯(VAc)、丙烯酸(AA)单体为基础,采用双丙酮丙烯酰胺(DAAM)/己二酸二酰肼(ADH)外交联体系,通过预乳化和半连续加料工艺制备了外交联型丙烯酸酯乳液压敏胶.采用红外光谱(FTIR)、透射电镜(TEM)、热重分析(TGA)等手段对其进行了表征和分析.并研究了软硬单体配比[m(BA)∶m(VAc)]、官能单体(AA)用量及外交联体系(DAAM/ADH)用量对压敏胶性能的影响.结果表明,通过调节软硬单体配比和官能单体用量可以使压敏胶性能达到一个较优的水平.当m(BA)∶m(VAc)=85∶15,w(AA)=3%时,压敏胶初粘力为17号球,180°剥离强度为504 N/m,室温持粘力>30 d,高温(100℃)持粘力为140 min.外交联体系DAAM/ADH的引入可以在对初粘力和180°剥离强度影响较小的情况下显著提高压敏胶的高温持粘力到540 min,从而得到高温持粘力优异的外交联型丙烯酸酯乳液压敏胶.%A series of post cross-linked acrylic emulsion adhesives were synthesized by pre-emulsion technology and semi-continuous emulsion polymerization.Butyl acrylate(BA),vinyl acetate(VAc) and acrylic acid (AA) were used as main monomers and diacetone-acrylamide (DAAM) /adipic dihydrazide (ADH) as post cross-linker.The emulsion polymer was characterized by means of Fourier transform infrared (FTIR) analysis,transmission electron microscopy (TEM) and thermo-gravimetric analysis (TGA).The polymer structures and the cross-linking between emulsion particles have been characterized by means of FTIR spectroscopy and TEM photographs,respectively.TGA indicated its potential use in the environment of high temperature.The corresponding pressure sensitive adhesive (PSA) tapes with a thickness of 50 μm were prepared.Their properties,including tack,180° peel strength,and shear strength at room temperature and 100 ℃,and the influence of m(BA) ∶m (VAc),AA content and DAAM/ADH content on those properties were studied.The results

  17. Random close packing of polydisperse jammed emulsions

    Science.gov (United States)

    Brujic, Jasna

    2010-03-01

    Packing problems are everywhere, ranging from oil extraction through porous rocks to grain storage in silos and the compaction of pharmaceutical powders into tablets. At a given density, particulate systems pack into a mechanically stable and amorphous jammed state. Theoretical frameworks have proposed a connection between this jammed state and the glass transition, a thermodynamics of jamming, as well as geometric modeling of random packings. Nevertheless, a simple underlying mechanism for the random assembly of athermal particles, analogous to crystalline ordering, remains unknown. Here we use 3D measurements of polydisperse packings of emulsion droplets to build a simple statistical model in which the complexity of the global packing is distilled into a local stochastic process. From the perspective of a single particle the packing problem is reduced to the random formation of nearest neighbors, followed by a choice of contacts among them. The two key parameters in the model, the available space around a particle and the ratio of contacts to neighbors, are directly obtained from experiments. Remarkably, we demonstrate that this ``granocentric'' view captures the properties of the polydisperse emulsion packing, ranging from the microscopic distributions of nearest neighbors and contacts to local density fluctuations and all the way to the global packing density. Further applications to monodisperse and bidisperse systems quantitatively agree with previously measured trends in global density. This model therefore reveals a general principle of organization for random packing and lays the foundations for a theory of jammed matter.

  18. Detecting plastic events in emulsions simulations

    Science.gov (United States)

    Lulli, Matteo; Matteo Lulli, Massimo Bernaschi, Mauro Sbragaglia Team

    2016-11-01

    Emulsions are complex systems which are formed by a number of non-coalescing droplets dispersed in a solvent leading to non-trivial effects in the overall flowing dynamics. Such systems possess a yield stress below which an elastic response to an external forcing occurs, while above the yield stress the system flows as a non-Newtonian fluid, i.e. the stress is not proportional to the shear. In the solid-like regime the network of the droplets interfaces stores the energy coming from the work exerted by an external forcing, which can be used to move the droplets in a non-reversible way, i.e. causing plastic events. The Kinetic-Elasto-Plastic (KEP) theory is an effective theory describing some features of the flowing regime relating the rate of plastic events to a scalar field called fluidity f =γ˙/σ , i.e. the inverse of an effective viscosity. Boundary conditions have a non-trivial role not captured by the KEP description. In this contribution we will compare numerical results against experiments concerning the Poiseuille flow of emulsions in microchannels with complex boundary geometries. Using an efficient computational tool we can show non-trivial results on plastic events for different realizations of the rough boundaries. The research leading to these results has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP7/2007- 2013)/ERC Grant Agreement no. [279004].

  19. Synthesis of berberine loaded polymeric nanoparticles by central composite design

    Science.gov (United States)

    Mehra, Meenakshi; Sheorain, Jyoti; Kumari, Santosh

    2016-04-01

    Berberine is an isoquinoline alkaloid which is extracted from bark and roots of Berberis vulgaris plant. It has been used in ayurvedic medicine as it possess antimicrobial, antidiabetic, anticancer, antioxidant properties etc. But poor solubility of berberine leads to poor stability and bioavailability in medical formulations decreasing its efficacy. Hence nanoformulations of berberine can help in removing the limiting factors of alkaloid enhancing its utilization in pharmaceutical industry. Sodium alginate polymer was used to encapsulate berberine within nanoparticles by emulsion solvent evaporation method using tween 80 as a surfactant. Two factors and three level in central composite design was used to study the formulation. The optimized formulation (1% v/v of Tween 80 and 0.01% w/v of sodium alginate) of polymeric nanoparticles was taken for further evaluations. The size of synthesized nanoparticles was found to be 71.18 nm by particle size analysis (PSA). The berberine loaded polymeric nanoparticles showed better antibacterial activity compared to aqueous solution of berberine by well diffusion assay.

  20. Further progress for a fast scanning of nuclear emulsions with Large Angle Scanning System

    Science.gov (United States)

    Alexandrov, A.; Tioukov, V.; Vladymyrov, M.

    2014-02-01

    The LASSO (Large Angle Scanning System for OPERA) is a scanning system designed in the framework of the OPERA experiment as a result of several R&Ds aimed to improve the performance of the European Scanning System (ESS) by increasing the scanning speed, the angular acceptance and the efficiency in microtrack reconstruction. The novel Continuous Motion (CM) scanning approach allows to double the ESS nominal speed without any changes in the hardware set-up. The LASSO modular design makes the system easily adaptable to new hardware. The novel microtrack reconstruction algorithm has been developed to be efficient in both standard Stop&Go (SG) and CM modes, performing a number of corrections during the processing like corrections for vibrations, optical distortions, field of view curvature. As an intermediate step it reconstructs silver grains positions inside emulsion layer to make a transition from 2D images to real 3D traces of a charged particle. This allows the algorithm to have no internal limits on the slope of microtracks being equally efficient on all angles. The LASSO has been used for about one year for mass production scanning of emulsion films of OPERA, Muon Radiography and also of films employed to study nuclear fragmentation of ion beams used in medical physics. More than 50000 cm2 of the emulsion surface have been analyzed during this period.