The Rebirth of Waste Cooking Oil to Novel Bio-based Surfactants

Science.gov (United States)

Zhang, Qi-Qi; Cai, Bang-Xin; Xu, Wen-Jie; Gang, Hong-Ze; Liu, Jin-Feng; Yang, Shi-Zhong; Mu, Bo-Zhong

2015-05-01

Waste cooking oil (WCO) is a kind of non-edible oil with enormous quantities and its unreasonable dispose may generate negative impact on human life and environment. However, WCO is certainly a renewable feedstock of bio-based materials. To get the rebirth of WCO, we have established a facile and high-yield method to convert WCO to bio-based zwitterionic surfactants with excellent surface and interfacial properties. The interfacial tension between crude oil and water could reach ultra-low value as 0.0016 mN m-1 at a low dosage as 0.100 g L-1 of this bio-based surfactant without the aid of extra alkali, which shows a strong interfacial activity and the great potential application in many industrial fields, in particular, the application in enhanced oil recovery in oilfields in place of petroleum-based surfactants.

Cooperative Effects of Zwitterionic-Ionic Surfactant Mixtures on the Interfacial Water Structure Revealed by Sum Frequency Generation Vibrational Spectroscopy.

Science.gov (United States)

Pan, Xuecong; Yang, Fangyuan; Chen, Shunli; Zhu, Xuefeng; Wang, Chuanyi

2018-05-08

Cooperative effects of a series of equimolar binary zwitterionic-ionic surfactant mixtures on the interfacial water structure at the air-water interfaces have been studied by sum frequency generation vibrational spectroscopy (SFG-VS). For zwitterionic surfactant palmityl sulfobetaine (SNC 16 ), anionic surfactant sodium hexadecyl sulfate (SHS), and cationic surfactant cetyltrimethylammonium bromide (CTAB) with the same length of alkyl chain, significantly enhanced ordering of interfacial water molecules was observed for the zwitterionic-anionic surfactant mixtures SNC 16 -SHS, indicating that SNC 16 interacts more strongly with SHS than with CTAB because of the strong headgroup-headgroup electrostatic attraction for SNC 16 -SHS. Meanwhile, the SFG amplitude ratio of methyl and methylene symmetric stretching modes was used to verify the stronger interaction between SNC 16 and SHS. The conformational order indicator increased from 0.64 for SNC 16 to 7.17 for SNC 16 -SHS but only 0.94 for SNC 16 -CTAB. In addition, another anionic surfactant sodium dodecyl sulfate (SDS) was introduced to study the influence of chain-chain interaction. Decreased SFG amplitude of interfacial water molecules for SNC 16 -SDS was observed. Therefore, both the headgroup-headgroup electrostatic interaction and chain-chain van der Waals attractive interaction of the surfactants play an important role in enhancing the ordering of interfacial water molecules. The results provided experimental and theoretical bases for practical applications of the surfactants.

Comparison of rSP-C surfactant with natural and synthetic surfactants after late treatment in a rat model of the acute respiratory distress syndrome

Science.gov (United States)

Häfner, Dietrich; Germann, Paul-Georg; Hauschke, Dieter

1998-01-01

In a previous paper we showed that an SP-C containing surfactant preparation has similar activity as bovine-derived surfactants in a rat lung lavage model of the adult respiratory distress syndrome. In this study surfactant was given ten minutes after the last lavage (early treatment). In the present investigation we were interested how different surfactant preparations behave when they are administered 1 h after the last lavage (late treatment). Four protein containing surfactants (rSP-C surfactant, bLES, Infasurf and Survanta) were compared with three protein-free surfactants (ALEC, Exosurf and the phospholipid (PL) mixture of the rSP-C surfactant termed PL surfactant) with respect to their ability to improve gas exchange in this more stringent model when surfactant is given one hour after the last lavage. For better comparison of the surfactants the doses were related to phospholipids. The surfactants were given at doses of 25, 50 and 100 mg kg−1 body weight. The surfactants were compared to an untreated control group that was only ventilated for the whole experimental period. Tracheotomized rats (8–12 per dose and surfactant) were pressure-controlled ventilated (Siemens Servo Ventilator 900C) with 100% oxygen at a respiratory rate of 30 breaths min−1, inspiration expiration ratio of 1 : 2, peak inspiratory pressure of 28 cmH2O at positive endexpiratory pressure (PEEP) of 8 cmH2O. Animals were ventilated for one hour after the last lavage and thereafter the surfactants were intratracheally instilled. During the whole experimental period the ventilation was not changed. Partial arterial oxygen pressures (PaO2, mmHg) at 30 min and 120 min after treatment were used for statistical comparison. All protein containing surfactants caused a dose-dependent increase of the reduced PaO2 values at 30 min after treatment. The protein-free surfactants showed only weak dose-dependent increase in PaO2 values at this time. This difference between the

Mechanisms of polyelectrolyte enhanced surfactant adsorption at the air-water interface.

Science.gov (United States)

Stenger, Patrick C; Palazoglu, Omer A; Zasadzinski, Joseph A

2009-05-01

Chitosan, a naturally occurring cationic polyelectrolyte, restores the adsorption of the clinical lung surfactant Survanta to the air-water interface in the presence of albumin at much lower concentrations than uncharged polymers such as polyethylene glycol. This is consistent with the positively charged chitosan forming ion pairs with negative charges on the albumin and lung surfactant particles, reducing the net charge in the double-layer, and decreasing the electrostatic energy barrier to adsorption to the air-water interface. However, chitosan, like other polyelectrolytes, cannot perfectly match the charge distribution on the surfactant, which leads to patches of positive and negative charge at net neutrality. Increasing the chitosan concentration further leads to a reduction in the rate of surfactant adsorption consistent with an over-compensation of the negative charge on the surfactant and albumin surfaces, which creates a new repulsive electrostatic potential between the now cationic surfaces. This charge neutralization followed by charge inversion explains the window of polyelectrolyte concentration that enhances surfactant adsorption; the same physical mechanism is observed in flocculation and re-stabilization of anionic colloids by chitosan and in alternate layer deposition of anionic and cationic polyelectrolytes on charged colloids.

Evaluation of a common commercial surfactant in a water recycle system

International Nuclear Information System (INIS)

Rector, T.; Jackson, A.; Rainwater, K.; Pickering, S.

2002-01-01

The fate of a common commercial surfactant was investigated in the biological reactors of a water recycle system. A NO 2 - reducing packed-bed bioreactor was employed to evaluate degradation of surfactant present in a typical greywater stream. The research was conducted to determine if an alternative commercial surfactant could be used in a biological water recycle system proposed for space travel in place of the current surfactant. The commercial soap used in the research was Pert Plus for Kids (PPK), which contains sodium laureth sulfate (SLES) as the active surfactant. Experiments included a combination of microcosm studies as well as a continuous-flow packed-bed bioreactor. The hydraulic retention time of the packed-bed bioreactor was varied through changes in flow rate to yield different steady-state values for NO 2 -N, TOC, and COD. Steady-state values will allow the determination of the bacterial kinetic parameters. Initial results suggest that the commercial surfactant may be difficult to treat in the time frame of typical biological systems. NO 2 - reduction was favorable in the packed-bed reactor, but TOC removal rates did not correspond to the NO 2 - removal. It is theorized that, due to its high K oc value (1200), SLES has an affinity to absorb to the media contained in the bed, which in turn allows for adsorption of the surfactant. Future research will include development of an isotherm model to characterize the adsorption rates and correlate them to surfactant removal. (author)

Surfactant-adsorption-induced initial depinning behavior in evaporating water and nanofluid sessile droplets.

Science.gov (United States)

Zhong, Xin; Duan, Fei

2015-05-19

A surfactant-induced autophobic effect has been observed to initiate an intense depinning behavior at the initial stage of evaporation in both pure water and nanofluid sessile droplets. The cationic surfactant adsorbing to the negatively charged silicon wafer makes the solid surface more hydrophobic. The autophobing-induced depinning behavior, leading to an enlarged contact angle and a shortened base diameter, takes place only when the surfactant concentration is below its critical micelle concentration (cmc). The initial spreading degree right before the droplet retraction, the retracting velocity of the contact line, and the duration of the initial droplet retraction are shown to depend negatively on the surfactant concentration below the cmc. An unexpected enhancement in the initial depinning has been found in the nanofluid droplets, possibly resulting from the hydrophilic interplay between the graphite nanoparticle deposition and the surfactant molecules. Such promotion of the initial depinning due to the nanoparticle deposition makes the droplet retract even at a surfactant concentration higher than the cmc (1.5 cmc). The resulting deposition formed in the presence of the depinning behavior has great enhancement for coffee-ring formation as compared to the one free of surfactant, implying that the formation of a coffee ring does not require the pinning of the contact line during the entire drying process.

Long Term Field Development of a Surfactant Modified Zeolite/Vapor Phase Bioreactor System for Treatment of Produced Waters for Power Generation

Energy Technology Data Exchange (ETDEWEB)

Lynn Katz; Kerry Kinney; Robert Bowman; Enid Sullivan; Soondong Kwon; Elaine Darby; Li-Jung Chen; Craig Altare

2007-12-31

The main goal of this research was to investigate the feasibility of using a combined physicochemical/biological treatment system to remove the organic constituents present in saline produced water. In order to meet this objective, a physical/chemical adsorption process was developed and two separate biological treatment techniques were investigated. Two previous research projects focused on the development of the surfactant modified zeolite adsorption process (DE-AC26-99BC15221) and development of a vapor phase biofilter (VPB) to treat the regeneration off-gas from the surfactant modified zeolite (SMZ) adsorption system (DE-FC26-02NT15461). In this research, the SMZ/VPB was modified to more effectively attenuate peak loads and to maintain stable biodegradation of the BTEX constituents from the produced water. Specifically, a load equalization system was incorporated into the regeneration flow stream. In addition, a membrane bioreactor (MBR) system was tested for its ability to simultaneously remove the aromatic hydrocarbon and carboxylate components from produced water. The specific objectives related to these efforts included the following: (1) Optimize the performance VPBs treating the transient loading expected during SMZ regeneration: (a) Evaluate the impact of biofilter operating parameters on process performance under stable operating conditions. (b) Investigate how transient loads affect biofilter performance, and identify an appropriate technology to improve biological treatment performance during the transient regeneration period of an SMZ adsorption system. (c) Examine the merits of a load equalization technology to attenuate peak VOC loads prior to a VPB system. (d) Evaluate the capability of an SMZ/VPB to remove BTEX from produced water in a field trial. (2) Investigate the feasibility of MBR treatment of produced water: (a) Evaluate the biodegradation of carboxylates and BTEX constituents from synthetic produced water in a laboratory-scale MBR. (b

Separation of oil and grease from oil sludge using surfactant

International Nuclear Information System (INIS)

Ainon Abdul Aziz; Syed Hakimi Sakuma Syed Ahmad; Zalina Laili

2005-01-01

The objective of the experiments was to observe the efficiency of the surfactant to remove oil and grease from oil sludges using various surfactant concentration ranging from 10 %, 15 %, 20 % and 30 %. The surfactant solution consists of two mixtures of Aqua 2000 and D Bond. The oil sludge were subjected to heating and surfactant treatment process. Remaining oil and grease concentration were observed on the oil sludges after treatment. Small scale experiments were conducted by heating process, without heating process and heating process with addition of sodium chloride. Surfactant solution was added in each process. Results shows that there is separation of oil and grease from the oil sludges. There were formation of mini emulsions (oil in water). The higher the concentration of surfactant used, the higher the concentrations of mini emulsion formed as observed. Solid remains after the treatment process were found to contain lesser oil concentration with presence of bitumen, sediment, organic and inorganic materials. After a washing process using distilled water, the solid was still black but less oily than before the treatment. There is no separation of oil occurred in aqueous solution for the control experiment. (Author)

The influence of surfactant on mass transfer coefficients in evaporation of volatile organic compound from water basin

Directory of Open Access Journals (Sweden)

Bunyakan, C.

2002-04-01

Full Text Available Volatile organic compounds (VOCs have been found in wastewater of many chemical industries. Evaporation of VOCs from open water basin in waste treatment facilities causes air-pollution and has been regulated in many countries. Reduction or prevention of VOCs evaporation from open water basin is then necessary. The aim of this research was to investigate the influence of surface film generated by an insoluble surfactant on the mass transfer coefficient of VOCs evaporating from water. Hexadecanol and octadecanol were used as surfactant in this investigation with the amount in the range of 0 to 35 μg/cm2 and 0 to 25 μg/cm2, respectively. The VOCs used in this study were methanol, acetone, methyl ethyl ketone and toluene. The experimental results showed that the surfactant film can reduce the gas film and liquid coefficients by 56 and 80 %, respectively. The suitable amounts of the surfactant were 25 μg/cm2 for hexadecanol and 15 μg/cm2 for octadecanol. From this investigation we can conclude that covering the water surface with a film of hexadecanol or octadecanol could significantly reduce the VOCs evaporation rate.Finally, the empirical equations correlating gas film and liquid film coefficient to amount of surfactants were developed and verified against the experimental data. The predicted values of the overall mass transfer coefficients, obtained by using these empirical equations, were in good agreement with the measured values. Thus the empirical equations of mass transfer coefficients developed in this work can be used to predict the evaporation rates of VOCs from water surface covered by hexadecanol or octadecanol film.

Green Walls as an Approach in Grey Water Treatment

Science.gov (United States)

Rysulova, Martina; Kaposztasova, Daniela; Vranayova, Zuzana

2017-10-01

Grey water contributes significantly to waste water parameters such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total phosphorus (Ptotal), total nitrogen (Ntotal), ammonium, boron, metals, salts, surfactants, synthetic chemicals, oils and greases, xenobiotic substances and microorganisms. Concentration of these pollutants and the water quality highlights the importance of treatment process in grey water systems. Treatment technologies operating under low energy and maintenance are usually preferred, since they are more cost effective for users. Treatment technologies based on natural processes represent an example of such technology including vegetated wall. Main aim of this paper is to introduce the proposal of vegetated wall managing grey water and brief characteristic of proposed system. Is expected that prepared experiment will establish the purifying ability and the potential of green wall application as an efficient treatment technology.

Formulation of insecticide profenofos using Surfactant Diethanolamide (DEA) based on palm olein

Science.gov (United States)

Dewi, H. S.; Rahayuningsih, M.; Hambali, E.

2017-05-01

Soybean is one of the major food commodities in Indonesia that the consumption is increasing each year, but this is not in line with the domestic soybean production capacity. One cause of the low production capacity is the armyworm attact. Generally, the armyworm attack controled by spread insecticide profenofos. Profenofos need to be dissolved, but profenofos couldn’t dissolved in water. So that, it need the right formulation between the solvent and other ingredients which can supprotprofenofos performance. One of that ingredient is surfactant. This research used surfactant diethanolamide (DEA) based on palm olein. DEAfunction in insecticide formulation are as homogenizer, dispersant, sticker and spreader agent.The aims of this research are to obtain the best emultion insecticide product based on profenofos as the active ingredients and DEA as the surfactant, moreover it also to obtain information of the physico-chemical properties. The formulation test performed with compeletely randomized design (CRD) with two factors, first factor is DEA concentrationand the second factor is profenofos concentration. Data of physico-chemical properties test was analyzed by analysis of variance (ANOVA) and significant result tested by Duncant Multiple Range Test (DMRT).The result showed that, surfactant DEA could make good emultion between profenofos and sodium ethoxide as the solvent. The best treatment which obtain from formulation stage is concentrate with DEA 10% and profenofos 40%. Physico-chemical properties test result showed that droplet size is 1,76-2,07 µm, contact angle 11,575-24,218°, density 0,996-0,998 g/cm3, surface tension 16,56-40,72 dyne/cm, viscosity 1,032-1,078 Cp and pH 6,87-8,22.

Review of the technological approaches for grey water treatment and reuses.

Science.gov (United States)

Li, Fangyue; Wichmann, Knut; Otterpohl, Ralf

2009-05-15

Based on literature review, a non-potable urban grey water reuse standard is proposed and the treatment alternatives and reuse scheme for grey water reuses are evaluated according to grey water characteristics and the proposed standard. The literature review shows that all types of grey water have good biodegradability. The bathroom and the laundry grey water are deficient in both nitrogen and phosphors. The kitchen grey water has a balanced COD: N: P ratio. The review also reveals that physical processes alone are not sufficient to guarantee an adequate reduction of the organics, nutrients and surfactants. The chemical processes can efficiently remove the suspended solids, organic materials and surfactants in the low strength grey water. The combination of aerobic biological process with physical filtration and disinfection is considered to be the most economical and feasible solution for grey water recycling. The MBR appears to be a very attractive solution in collective urban residential buildings.

Gemini Surfactant-Modified Activated Carbon for Remediation of Hexavalent Chromium from Water

Directory of Open Access Journals (Sweden)

Yingying Zhou

2018-01-01

Full Text Available Gemini surfactants, with double hydrophilic and hydrophobic groups, offer potentially orders of magnitude greater surface activity compared to similar single unit molecules. A cationic Gemini surfactant (Propyl didodecyldimethylammonium Bromide, PDDDAB and a conventional cationic surfactant (Dodecyltrimethylammonium Bromide, DTAB were used to pre-treat and generate activated carbon. The removal efficiency of the surfactant-modified activated carbon through adsorption of chromium(VI was investigated under controlled laboratory conditions. Fourier-transform infrared spectroscopy (FT-IR and scanning electron microscopy (SEM were used to investigate the surface changes of surfactant-modified activated carbon. The effect of important parameters such as adsorbent dosage, pH, ionic strength and contact time were also investigated. The chromium(VI was adsorbed more significantly on the Gemini surfactant-modified activated carbon than on the conventional surfactant-modified activated carbon. The correlation coefficients show the data best fit the Freundlich model, which confirms the monolayer adsorption of chromium(VI onto Gemini surfactant-modified activated carbon. From this assessment, the surfactant-modified (especially Gemini surfactant-modified activated carbon in this study showed promise for practical applications to treat water pollution.

Radioactive slurry waste treatment (2) - surfactants dose effects on filtration

International Nuclear Information System (INIS)

Jung, K. H.; Park, S. K.; Jung, W. S.; Baek, S. T.; Jung, K. J.

1999-01-01

The influence of anionic flocculants on the dewatering of radioactive slurries has been investigated in a laboratory-scale vacuum filtration unit. Simultaneously the influence of certain surfactants has also been investigated. Test results show that the flocculated filter cake generally contains higher residual water than the unflocculated cake. The non-ionic surfactant was effective in reducing the moisture content of the cake

Viscosity of the oil-in-water Pickering emulsion stabilized by surfactant-polymer and nanoparticle-surfactant-polymer system

Science.gov (United States)

Sharma, Tushar; Kumar, G. Suresh; Chon, Bo Hyun; Sangwai, Jitendra S.

2014-11-01

Information on the viscosity of Pickering emulsion is required for their successful application in upstream oil and gas industry to understand their stability at extreme environment. In this work, a novel formulation of oil-in-water (o/w) Pickering emulsion stabilized using nanoparticle-surfactant-polymer (polyacrylamide) system as formulated in our earlier work (Sharma et al., Journal of Industrial and Engineering Chemistry, 2014) is investigated for rheological stability at high pressure and high temperature (HPHT) conditions using a controlled-strain rheometer. The nanoparticle (SiO2 and clay) concentration is varied from 1.0 to 5.0 wt%. The results are compared with the rheological behavior of simple o/w emulsion stabilized by surfactant-polymer system. Both the emulsions exhibit non-Newtonian shear thinning behavior. A positive shift in this behavior is observed for surfactant-polymer stabilized emulsion at high pressure conditions. Yield stress is observed to increase with pressure for surfactant-polymer emulsion. In addition, increase in temperature has an adverse effect on the viscosity of emulsion stabilized by surfactant-polymer system. In case of nanoparticle-surfactant-polymer stabilized o/w emulsion system, the viscosity and yield stress are predominantly constant for varying pressure and temperature conditions. The viscosity data for both o/w emulsion systems are fitted by the Herschel-Bulkley model and found to be satisfactory. In general, the study indicates that the Pickering emulsion stabilized by nanoparticle-surfactant-polymer system shows improved and stable rheological properties as compared to conventional emulsion stabilized by surfactant-polymer system indicating their successful application for HPHT environment in upstream oil and gas industry.

Modeling adsorption of cationic surfactants at air/water interface without using the Gibbs equation.

Science.gov (United States)

Phan, Chi M; Le, Thu N; Nguyen, Cuong V; Yusa, Shin-ichi

2013-04-16

The Gibbs adsorption equation has been indispensable in predicting the surfactant adsorption at the interfaces, with many applications in industrial and natural processes. This study uses a new theoretical framework to model surfactant adsorption at the air/water interface without the Gibbs equation. The model was applied to two surfactants, C14TAB and C16TAB, to determine the maximum surface excesses. The obtained values demonstrated a fundamental change, which was verified by simulations, in the molecular arrangement at the interface. The new insights, in combination with recent discoveries in the field, expose the limitations of applying the Gibbs adsorption equation to cationic surfactants at the air/water interface.

Effect of surfactants on the fluorescence spectra of water-soluble ...

Indian Academy of Sciences (India)

TECS

Effect of surfactants on the fluorescence spectra of water-soluble. MEHPPV ... polyacrylic acid (PAA) chains grafted onto their backbone were found to be water soluble, and they exhi- ..... in other words the variation of emission intensity.

A multicenter, randomized trial comparing synthetic surfactant with modified bovine surfactant extract in the treatment of neonatal respiratory distress syndrome

NARCIS (Netherlands)

Adams, E; Vollman, J; Giebner, D; Maurer, M; Dreyer, G; Bailey, L; Anderson, M; Mefford, L; Beaumont, E; Sutton, D; Puppala, B; Mangurten, HH; Secrest, J; Lewis, WJ; Carteaux, P; Bednarek, F; Welsberger, S; Gosselin, R; Pantoja, AF; Belenky, A; Campbell, P; Patole, S; Duenas, M; Kelly, M; Alejo, W; Lewallen, P; DeanLieber, S; Hanft, M; Ferlauto, J; Newell, RW; Bagwell, J; Levine, D; Lipp, RW; Harkavy, K; Vasa, R; Birenbaum, H; Broderick, KA; Santos, AQ; Long, BA; Gulrajani, M; Stern, M; Hopgood, G; Hegyi, T; Alba, J; Christmas, L; McQueen, M; Nichols, N; Brown, M; Quissell, BJ; Rusk, C; Marks, K; Gifford, K; Hoehn, G; Pathak, A; Marino, B; Hunt, P; Fox, [No Value; Sharpstein, C; Feldman, B; Johnson, N; Beecham, J; Balcom, R; Helmuth, W; Boylan, D; Frakes, C; Magoon, M; Reese, K; Schwersenski, J; Schutzman, D; Soll, R; Horbar, JD; Leahy, K; Troyer, W; Juzwicki, C; Anderson, P; Dworsky, M; Reynolds, L; Urrutia, J; Gupta, U; Adray, C

Objective. To compare the efficacy of a synthetic surfactant (Exosurf Neonatal, Burroughs-Wellcome Co) and a modified bovine surfactant extract (Survanta, Ross Laboratories) in the treatment of neonatal respiratory distress syndrome (RDS). Design. Multicenter, randomized trial. Setting. Thirty-eight

The effect of the head group on branched-alkyl chain surfactants in glycolipid/n-octane/water ternary system.

Science.gov (United States)

Nainggolan, Irwana; Radiman, Shahidan; Hamzah, Ahmad Sazali; Hashim, Rauzah

2009-10-01

Two novel glycolipids have been synthesized and their phase behaviour studied. They have been characterized using FT-IR, FAB and 13C NMR and 1H NMR to ensure the purity of novel glycolipids. The two glycolipids are distinguished based on the head group of glycolipids (monosaccharide/glucose and disaccharide/maltose). These two novel glycolipids have been used as surfactant to perform two phase diagrams. Phase behaviours that have been investigated are 2-hexyldecyl-beta-D-glucopyranoside (2-HDG)/n-octane/water ternary system and 2-hexyldecyl-beta-D-maltoside (2-HDM)/n-octane/water ternary system. SAXS and polarizing optical microscope have been used to study the phase behaviours of these two surfactants in ternary phase diagram. Study of effect of the head group on branched-alkyl chain surfactants in ternary system is a strategy to derive the structure-property relationship. For comparison, 2-HDM and 2-HDG have been used as surfactant in the same ternary system. The phase diagram of 2-hexyldecyl-beta-D-maltoside/n-octane/water ternary system exhibited a Lalpha phase at a higher concentration regime, followed with two phases and a micellar solution region in a lower concentration regime. The phase diagram of 2-HDG/water/n-octane ternary system shows hexagonal phase, cubic phase, rectangular ribbon phase, lamellar phase, cubic phase as the surfactant concentration increase.

Strong cooperative effect of oppositely charged surfactant mixtures on their adsorption and packing at the air-water interface and interfacial water structure.

Science.gov (United States)

Nguyen, Khoi T; Nguyen, Tuan D; Nguyen, Anh V

2014-06-24

Remarkable adsorption enhancement and packing of dilute mixtures of water-soluble oppositely-charged surfactants, sodium dodecyl sulfate (SDS) and dodecyl amine hydrochloride (DAH), at the air-water interface were observed by using sum frequency generation spectroscopy and tensiometry. The interfacial water structure was also observed to be significantly influenced by the SDS-DAH mixtures, differently from the synergy of the single surfactants. Most strikingly, the obtained spectroscopic evidence suggests that the interfacial hydrophobic alkyl chains of the binary mixtures assemble differently from those of single surfactants. This study highlights the significance of the cooperative interaction between the headgroups of oppositely charged binary surfactant systems and subsequently provides some insightful observations about the molecular structure of the air-aqueous interfacial water molecules and, more importantly, about the packing nature of the surfactant hydrophobic chains of dilute SDS-DAH mixtures of concentration below 1% of the CMC.

Tensiometry and dilational rheology of mixed β-lactoglobulin/ionic surfactant adsorption layers at water/air and water/hexane interfaces.

Science.gov (United States)

Dan, Abhijit; Gochev, Georgi; Miller, Reinhard

2015-07-01

Oscillating drop tensiometry was applied to study adsorbed interfacial layers at water/air and water/hexane interfaces formed from mixed solutions of β-lactoglobulin (BLG, 1 μM in 10 mM buffer, pH 7 - negative net charge) and the anionic surfactant SDS or the cationic DoTAB. The interfacial pressure Π and the dilational viscoelasticity modulus |E| of the mixed layers were measured for mixtures of varying surfactant concentrations. The double capillary technique was employed which enables exchange of the protein solution in the drop bulk by surfactant solution (sequential adsorption) or by pure buffer (washing out). The first protocol allows probing the influence of the surfactant on a pre-adsorbed protein layer thus studying the protein/surfactant interactions at the interface. The second protocol gives access to the residual values of Π and |E| measured after the washing out procedure thus bringing information about the process of protein desorption. The DoTAB/BLG complexes exhibit higher surface activity and higher resistance to desorption in comparison with those for the SDS/BLG complexes due to hydrophobization via electrostatic binding of surfactant molecules. The neutral DoTAB/BLG complexes achieve maximum elastic response of the mixed layer. Mixed BLG/surfactant layers at the water/oil interface are found to reach higher surface pressure and lower maximum dilational elasticity than those at the water/air surface. The sequential adsorption mode experiments and the desorption study reveal that binding of DoTAB to pre-adsorbed BLG globules is somehow restricted at the water/air surface in comparison with the case of complex formation in the solution bulk and subsequently adsorbed at the water/air surface. Maximum elasticity is achieved with washed out layers obtained after simultaneous adsorption, i.e. isolation of the most surface active DoTAB/BLG complex. These specific effects are much less pronounced at the W/H interface. Copyright © 2015 Elsevier Inc

Pulmonary surfactant and lung transplantation

NARCIS (Netherlands)

Erasmus, Michiel Elardus

1997-01-01

Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of

Nanofiltration: ion exchange system for effective surfactant removal from water solutions

Directory of Open Access Journals (Sweden)

I. Kowalska

2014-12-01

Full Text Available A system combining nanofiltration and ion exchange for highly effective separation of anionic surfactant from water solutions was proposed. The subjects of the study were nanofiltration polyethersulfone membranes and ion-exchange resins differing in type and structure. The quality of the treated solution was affected by numerous parameters, such as quality of the feed solution, membrane cut-off, resin type, dose and the solution contact time with the resin. A properly designed purification system made it possible to reduce the concentration of anionic surfactant below 1 mg L-1 from feed solutions containing surfactant in concentrations above the CMC value.

Adsorption of surfactant ions and binding of their counterions at an air/water interface.

Science.gov (United States)

Tagashira, Hiroaki; Takata, Youichi; Hyono, Atsushi; Ohshima, Hiroyuki

2009-01-01

An expression for the surface tension of an aqueous mixed solution of surfactants and electrolyte ions in the presence of the common ions was derived from the Helmholtz free energy of an air/water surface. By applying the equation to experimental data for the surface tension, the adsorption constant of surfactant ions onto the air/water interface, the binding constant of counterions on the surfactants, and the surface potential and surface charge density of the interface were estimated. The adsorption constant and binding constant were dependent on the species of surfactant ion and counterion, respectively. Taking account of the dependence of surface potential and surface charge density on the concentration of electrolyte, it was suggested that the addition of electrolyte to the aqueous surfactant solution brings about the decrease in the surface potential, the increase in the surface density of surfactant ions, and consequently, the decrease in the surface tension. Furthermore, it was found that the configurational entropy plays a predominant role for the surface tension, compared to the electrical work.

The influence of surfactant on mass transfer coefficients in evaporation of volatile organic compound from water basin

OpenAIRE

Bunyakan, C.; Malakarn, S.; Tongurai, C.

2002-01-01

Volatile organic compounds (VOCs) have been found in wastewater of many chemical industries. Evaporation of VOCs from open water basin in waste treatment facilities causes air-pollution and has been regulated in many countries. Reduction or prevention of VOCs evaporation from open water basin is then necessary. The aim of this research was to investigate the influence of surface film generated by an insoluble surfactant on the mass transfer coefficient of VOCs evaporating from water. Hexadeca...

Preconcentration of copper from natural water samples using ligand-less in situ surfactant-based solid phase extraction prior to FAAS determination

Directory of Open Access Journals (Sweden)

Sayed Zia Mohammadi

2014-01-01

Full Text Available In the present work, a simple and rapid ligand-less, in situ, surfactant-based solid phase extraction for the preconcentration of copper in water samples was developed. In this method, a cationic surfactant (n-dodecyltrimethylammonium bromide was dissolved in an aqueous sample followed by the addition of an appropriate ion-pairing agent (ClO4-. Due to the interaction between the surfactant and ion-pairing agent, solid particles were formed and subsequently used for the adsorption of Cu(OH2 and CuI. After centrifugation, the sediment was dissolved in 1.0 mL of 1 mol L-1 HNO3 in ethanol and aspirated directly into the flame atomic absorption spectrometer. In order to obtain the optimum conditions, several parameters affecting the performance of the LL-ISS-SPE, including the volumes of DTAB, KClO4, and KI, pH, and potentially interfering ions, were optimized. It was found that KI and phosphate buffer solution (pH = 9 could extract more than 95% of copper ions. The amount of copper ions in the water samples varied from 3.2 to 4.8 ng mL-1, with relative standard deviations of 98.5%-103%. The determination of copper in water samples was linear over a concentration range of 0.5-200.0 ng mL-1. The limit of detection (3Sb/m was 0.1 ng mL-1 with an enrichment factor of 38.7. The accuracy of the developed method was verified by the determination of copper in two certified reference materials, producing satisfactory results.

Properties of surfactant films in water-in-CO2 microemulsions obtained by small-angle neutron scattering.

Science.gov (United States)

Yan, Ci; Sagisaka, Masanobu; James, Craig; Rogers, Sarah; Alexander, Shirin; Eastoe, Julian

2014-12-01

The formation, stability and structural properties of normal liquid phase microemulsions, stabilized by hydrocarbon surfactants, comprising water and hydrocarbon oils can be interpreted in terms of the film bending rigidity (energy) model. Here, this model is tested for unusual water-in-CO2 (w/c) microemulsions, formed at high pressure with supercritical CO2 (sc-CO2) as a solvent and fluorinated surfactants as stabilizers. Hence, it is possible to explore the generality of this model for other types of microemulsions. High Pressure Small-Angle Neutron Scattering (HP-SANS) has been used to study w/c microemulsions, using contrast variation to highlight scattering from the stabilizing fluorinated surfactant films: these data show clear evidence for spherical core-shell structures for the microemulsion droplets. The results extend understanding of w/c microemulsions since previous SANS studies are based only on scattering from water core droplets. Here, detailed structural parameters for the surfactant films, such as thickness and film bending energy, have been extracted from the core-shell SANS profiles revealed by controlled contrast variation. Furthermore, at reduced CO2 densities (∼0.7gcm(-3)), elongated cylindrical droplet structures have been observed, which are uncommon for CO2 microemulsions/emulsions. The implications of the presence of cylindrical micelles and droplets for applications of CO2, and viscosity enhancements are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

Anaerobic digestion of amine-oxide-based surfactants: biodegradation kinetics and inhibitory effects.

Science.gov (United States)

Ríos, Francisco; Lechuga, Manuela; Fernández-Arteaga, Alejandro; Jurado, Encarnación; Fernández-Serrano, Mercedes

2017-08-01

Recently, anaerobic degradation has become a prevalent alternative for the treatment of wastewater and activated sludge. Consequently, the anaerobic biodegradability of recalcitrant compounds such as some surfactants require a thorough study to avoid their presence in the environment. In this work, the anaerobic biodegradation of amine-oxide-based surfactants, which are toxic to several organisms, was studied by measuring of the biogas production in digested sludge. Three amine-oxide-based surfactants with structural differences in their hydrophobic alkyl chain were tested: Lauramine oxide (AO-R 12 ), Myristamine oxide (AO-R 14 ) and Cocamidopropylamine oxide (AO-cocoamido). Results show that AO-R 12 and AO-R 14 inhibit biogas production, inhibition percentages were around 90%. AO-cocoamido did not cause inhibition and it was biodegraded until reaching a percentage of 60.8%. Otherwise, we fitted the production of biogas to two kinetic models, to a pseudo first-order model and to a logistic model. Production of biogas during the anaerobic biodegradation of AO-cocoamido was pretty good adjusted to the logistics model. Kinetic parameters were also determined. This modelling is useful to predict their behaviour in wastewater treatment plants and under anaerobic conditions in the environment.

Substrate-independent superliquiphobic coatings for water, oil, and surfactant repellency: An overview.

Science.gov (United States)

Bhushan, Bharat; Martin, Samuel

2018-09-15

Superliquiphobic surfaces that exhibit self-cleaning, antifouling, finger touch resistance, and low drag properties with high transparency are of interest in industrial applications including optical devices, solar panels, and self-cleaning windows. In this paper, an overview of coatings using a simple and scalable fabrication technique are presented that exhibit superoleophobic/philic properties, wear resistance, finger touch resistance, and transparency. The coating comprises hydrophobic SiO 2 nanoparticles with a binder of methylphenyl silicone resin. After ultraviolet-ozone treatment to the coating, an additional coating of fluorosilane or fluorosurfactant modifies the coated surface for superoleophobicity or superoleophilicity, respectively. Data for these coatings are presented showing substrate independency, the ability to repel surfactant-containing liquids such as shampoo and laundry detergent, oil-water separation, and the ability to survive up to 80 °C environments. The coatings were designed to have re-entrant geometry desirable for superoleophobicity with liquids with very low surface tension as well as surfactants. Copyright © 2018 Elsevier Inc. All rights reserved.

Fabrication of amine-functionalized magnetite nanoparticles for water treatment processes

International Nuclear Information System (INIS)

Chan, Candace C. P.; Gallard, Hervé; Majewski, Peter

2012-01-01

Amine-functionalized magnetite nanoparticles are synthesized by a one pot water based process using N-[3-(trimethoxysilyl)propyl]diethylenetriamine (TRIS) as surfactant. The prepared functionalised nanoparticles are characterised by BET surface area measurements, X-ray diffraction, zeta potential measurement, and X-ray photoelectron spectrometry (XPS). The results clearly show the presence of TRIS on the surface of the nanoparticles. XPS analysis indicates the presence of very small amounts of maghemite on the surface of the magnetite nanoparticles. Water treatment test shows that the prepared nanoparticles are capable to remove natural organic matter (NOM) from natural water samples. The removal of NOM by the prepared particles is characterized by analysing the dissolved organic carbon (DOC) content and UV absorbance at 254 nm (UV 254 ) after the treatment of the water samples at various doses and treatment times.

Fabrication of amine-functionalized magnetite nanoparticles for water treatment processes

Energy Technology Data Exchange (ETDEWEB)

Chan, Candace C. P. [University of South Australia, Ian Wark Research Institute (Australia); Gallard, Herve [Universite de Poitiers, Laboratoire de Chimie et Microbiologie de l' Eau (LCME)-UMR CNRS 6008 (France); Majewski, Peter, E-mail: peter.majewski@unisa.edu.au [Mawson Institute, University of South Australia, School of Advanced Manufacturing and Mechanical Engineering (Australia)

2012-03-15

Amine-functionalized magnetite nanoparticles are synthesized by a one pot water based process using N-[3-(trimethoxysilyl)propyl]diethylenetriamine (TRIS) as surfactant. The prepared functionalised nanoparticles are characterised by BET surface area measurements, X-ray diffraction, zeta potential measurement, and X-ray photoelectron spectrometry (XPS). The results clearly show the presence of TRIS on the surface of the nanoparticles. XPS analysis indicates the presence of very small amounts of maghemite on the surface of the magnetite nanoparticles. Water treatment test shows that the prepared nanoparticles are capable to remove natural organic matter (NOM) from natural water samples. The removal of NOM by the prepared particles is characterized by analysing the dissolved organic carbon (DOC) content and UV absorbance at 254 nm (UV{sub 254}) after the treatment of the water samples at various doses and treatment times.

Adsorption at air-water and oil-water interfaces and self-assembly in aqueous solution of ethoxylated polysorbate nonionic surfactants.

Science.gov (United States)

Penfold, Jeffrey; Thomas, Robert K; Li, Peixun X; Petkov, Jordan T; Tucker, Ian; Webster, John R P; Terry, Ann E

2015-03-17

The Tween nonionic surfactants are ethoxylated sorbitan esters, which have 20 ethylene oxide groups attached to the sorbitan headgroup and a single alkyl chain, lauryl, palmityl, stearyl, or oleyl. They are an important class of surfactants that are extensively used in emulsion and foam stabilization and in applications associated with foods, cosmetics and pharmaceuticals. A range of ethoxylated polysorbate surfactants, with differing degrees of ethoxylation from 3 to 50 ethylene oxide groups, have been synthesized and characterized by neutron reflection, small-angle neutron scattering, and surface tension. In conjunction with different alkyl chain groups, this provides the opportunity to modify their surface properties, their self-assembly in solution, and their interaction with macromolecules, such as proteins. Adsorption at the air-water and oil-water interfaces and solution self-assembly of the range of ethoxylated polysorbate surfactants synthesized are presented and discussed.

Surfactant treatment before first breath for respiratory distress syndrome in preterm lambs: comparison of a peptide-containing synthetic lung surfactant with porcine-derived surfactant

Directory of Open Access Journals (Sweden)

van Zyl JM

2013-08-01

, 240 and 300 minutes after treatment. The study continued for 5 hours. Results: Surfactant treatment led to a significant improvement in oxygenation within 30 minutes, with the Synsurf group and the Curosurf® group having significantly higher ratios between arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2; P = 0.021 compared to that of the control (saline-treated animals. Dynamic compliance improved in the three groups over time, with no intergroup differences. All of the surfactant-treated animals survived, and one in the saline group died before the study ended. Histology between groups was not different, showing mild–moderate injury patterns. Discussion: Treatment with surfactants before first breath clearly resulted in improved systemic oxygenation within 30 minutes of instillation. Both Synsurf- and Curosurf®-treated animals experienced similar and more sustained improvement in oxygenation and decreased calculated shunt compared to saline-treated animals. Keywords: respiratory distress syndrome, preterm lambs, pulmonary surfactant, gas exchange, oxygenation

Dilute Surfactant Methods for Carbonate Formations

Energy Technology Data Exchange (ETDEWEB)

Kishore K. Mohanty

2006-02-01

There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces

Adsorption of dissymmetric cationic gemini surfactants at silica/water interface

Science.gov (United States)

Sun, Yuhai; Feng, Yujun; Dong, Hongwei; Chen, Zhi

2007-05-01

Adsorption of a series of cationic gemini surfactants 12-2- m ( m = 8, 12, 16) on the surface of silica was investigated. The critical micelle concentrations, cmcs, of cationic gemini surfactants in the initial solutions and in the supernatants were measured by conductometry and tensiometer. The changes in cmc values indicate that the ion exchanges take place between polar groups of gemini surfactants adsorbed and ions bound on the surface of silica. The adsorption isotherms of cationic gemini surfactants were obtained by a solution depletion method. Based on the driving force, the adsorption includes two steps, one of which is ion exchange, and the other is hydrophobic interaction. In each step, the tendency of surfactant molecules in the solution to form aggregates or to be adsorbed on the silica varies with their structures. The maximum adsorption amount of gemini surfactants on the silica, τmax, decreases as increasing in the length of one alkyl chain, m, from 8, 12 to 16. So the results show that the adsorption behaviors of gemini surfactants are closely related to the dissymmetry of gemini molecules.

Defluorination of drinking water using surfactant modified zeolites ...

African Journals Online (AJOL)

This study focused on the removal of fluoridefrom groundwater by employing surfactant modified zeolites (SMZ) synthesized using locallyavailable kaolin material as precursor. The zeolite synthesis involved calcination of kaolin, alkaline fusion and hydrothermal treatment. The final product was modified with 5g/L ...

Thermodynamics of Surfactants, Block Copolymers and Their Mixtures in Water: The Role of the Isothermal Calorimetry

Science.gov (United States)

De Lisi, Rosario; Milioto, Stefania; Muratore, Nicola

2009-01-01

The thermodynamics of conventional surfactants, block copolymers and their mixtures in water was described to the light of the enthalpy function. The two methodologies, i.e. the van’t Hoff approach and the isothermal calorimetry, used to determine the enthalpy of micellization of pure surfactants and block copolymers were described. The van’t Hoff method was critically discussed. The aqueous copolymer+surfactant mixtures were analyzed by means of the isothermal titration calorimetry and the enthalpy of transfer of the copolymer from the water to the aqueous surfactant solutions. Thermodynamic models were presented to show the procedure to extract straightforward molecular insights from the bulk properties. PMID:19742173

Influence of Surfactant Structure on the Stability of Water-in-Oil Emulsions under High-Temperature High-Salinity Conditions

Directory of Open Access Journals (Sweden)

Abdelhalim I. A. Mohamed

2017-01-01

Full Text Available Emulsified water-in-oil (W/O systems are extensively used in the oil industry for water control and acid stimulation. Emulsifiers are commonly utilized to emulsify a water-soluble material to form W/O emulsion. The selection of a particular surfactant for such jobs is critical and certainly expensive. In this work, the impact of surfactant structure on the stability of W/O emulsions is investigated using the hydrophilic-lipophilic balance (HLB of the surfactant. Different commercial surfactants were evaluated for use as emulsifiers for W/O systems at high-temperature (up to 120°C high-salinity (221,673 ppm HTHS conditions. Diverse surfactants were examined including ethoxylates, polyethylene glycols, fluorinated surfactants, and amides. Both commercial Diesel and waste oil are used for the oleic phase to prepare the emulsified system. Waste oil has shown higher stability (less separation in comparison with Diesel. This work has successfully identified stable emulsified W/O systems that can tolerate HTHS environments using HLB approach. Amine Acetate family shows higher stability in comparison with Glycol Ether family and at even lower concentration. New insights into structure-surfactant stability relationship, beyond the HLB approach, are provided for surfactant selection.

Analysis of polyethoxylated surfactants in microemulsion-oil-water systems III. Fractionation and partitioning of polyethoxylated alcohol surfactants

International Nuclear Information System (INIS)

Marquez, N.; Bravo, B.; Ysambertt, F.; Chavez, G.; Subero, N.; Salager, J.L.

2002-01-01

Oligomer distribution of polyethoxylated alcohol and polyethoxylated nonylphenol surfactants is studied by normal and reverse-phase high performance liquid chromatography (HPLC). A RP8 column is able to efficiently separate these surfactants according to their alkyl chain (lipophilic) group, while silica and amino columns separate them according to their polyether chain length (hydrophilic group). Polyethoxylated alcohol and polyethoxylated nonylphenol oligomers selectively partition between the microemulsion-oil-water phases of a Winsor III system. Partitioning of these oligomers was analyzed by HPLC with RI detection. The logarithm of the partition coefficient between the water and oil linearly increases with the number of ethylene oxide groups per molecule of oligomer. For a same ethoxylation degree, the partition coefficient of a polyethoxylated tridecanol is found to be higher than the one of the corresponding nonylphenol specie. On the other hand, a polyethoxylated nonylphenol exhibits a higher solubilization than the matching polyethoxylated alcohol

Surfactant replacement therapy in a pediatric near-drowning case in manure.

Science.gov (United States)

Ugras, Meltem; Guraksin, Ozlem; Sen, Tolga Altug; Narci, Adnan; Alpay, Faruk

2012-09-01

Drowning is defined as suffocation by submersion especially in water and is a leading cause of injury-related death in children. Age groups at greatest risk are toddlers and male adolescents. It is the second most common cause of accidental death in children after road accidents. Treatment consists of resuscitation and stabilization. The use of surfactant after near-drowning in water is reported in the literature in few case reports.We report here a boy whose condition did not get better with conventional treatment, but dramatically improved after surfactant treatment after near-drowning in a fluid with manure.

Alkyl polyglucoside vs. ethoxylated surfactant-based microemulsions as vehicles for two poorly water-soluble drugs: physicochemical characterization and in vivo skin performance

Directory of Open Access Journals (Sweden)

Pajić Nataša Z. Bubić

2017-12-01

Full Text Available Two types of biocompatible surfactants were evaluated for their capability to formulate skin-friendly/non-irritant microemulsions as vehicles for two poorly water-soluble model drugs differing in properties and concentrations: alkyl polyglucosides (decyl glucoside and caprylyl/capryl glucoside and ethoxylated surfactants (glycereth-7-caprylate/ caprate and polysorbate 80. Phase behavior, structural inversion and microemulsion solubilization potential for sertaconazole nitrate and adapalene were found to be highly dependent on the surfactants structure and HLB value. Performed characterization (polarized light microscopy, pH, electrical conductivity, rheological, FTIR and DSC measurements indicated a formulation containing glycereth- 7-caprylate/caprate as suitable for incorporation of both drugs, whereas alkyl polyglucoside-based systems did not exhibit satisfying solubilization capacity for sertaconazole nitrate. Further, monitored parameters were strongly affected by sertaconazole nitrate incorporation, while they remained almost unchanged in adapalene-loaded vehicles. In addition, results of the in vivo skin performance study supported acceptable tolerability for all investigated formulations, suggesting selected microemulsions as promising carriers worth exploring further for effective skin delivery of model drugs.

Alkyl polyglucoside vs. ethoxylated surfactant-based microemulsions as vehicles for two poorly water-soluble drugs: physicochemical characterization and in vivo skin performance.

Science.gov (United States)

Pajić, Nataša Z Bubić; Todosijević, Marija N; Vuleta, Gordana M; Cekić, Nebojša D; Dobričić, Vladimir D; Vučen, Sonja R; Čalija, Bojan R; Lukić, Milica Ž; Ilić, Tanja M; Savić, Snežana D

2017-12-20

Two types of biocompatible surfactants were evaluated for their capability to formulate skin-friendly/non-irritant microemulsions as vehicles for two poorly water-soluble model drugs differing in properties and concentrations: alkyl polyglucosides (decyl glucoside and caprylyl/capryl glucoside) and ethoxylated surfactants (glycereth-7-caprylate/ caprate and polysorbate 80). Phase behavior, structural inversion and microemulsion solubilization potential for sertaconazole nitrate and adapalene were found to be highly dependent on the surfactants structure and HLB value. Performed characterization (polarized light microscopy, pH, electrical conductivity, rheological, FTIR and DSC measurements) indicated a formulation containing glycereth- 7-caprylate/caprate as suitable for incorporation of both drugs, whereas alkyl polyglucoside-based systems did not exhibit satisfying solubilization capacity for sertaconazole nitrate. Further, monitored parameters were strongly affected by sertaconazole nitrate incorporation, while they remained almost unchanged in adapalene-loaded vehicles. In addition, results of the in vivo skin performance study supported acceptable tolerability for all investigated formulations, suggesting selected microemulsions as promising carriers worth exploring further for effective skin delivery of model drugs.

Water-assisted and surfactant-free synthesis of cobalt ferrite nanospheres via solvothermal method

Energy Technology Data Exchange (ETDEWEB)

Bi, Yiqing [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Ren, Yanan [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); Bi, Feng [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); He, Tao, E-mail: het@nanoctr.cn [CAS Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China)

2015-10-15

With ethylene glycol as the solvent, monodispersed cobalt ferrite nanospheres were prepared via a solvothermal method assisted by water. The samples were mainly characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. The size of as-prepared products ranges from 10 nm to 200 nm. Size distribution and chemical composition were controlled by the amount of water and pH value in the reaction system. More important, suitable amount of water can avoid the use of surfactant. - Highlights: • Cobalt ferrite nanospheres were synthesized via solvothermal method assisted by water. • An introduction of suitable amount of water can avoid the use of surfactant. • The pH value of the precursor can be used to adjust the product composition.

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

International Nuclear Information System (INIS)

Alsabagh, A.M.; Migahed, M.A.; Awad, Hayam S.

2006-01-01

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV (∼96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

Energy Technology Data Exchange (ETDEWEB)

Alsabagh, A.M. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt); Migahed, M.A. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt)]. E-mail: mohamedatiyya707@hotmail.com; Awad, Hayam S. [Chemistry Department, Faculty of Girls for Science, Art and Education, Ain Shams University, Asmaa Fahmi Street, Helliopolis, Cairo (Egypt)

2006-04-15

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV ({approx}96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules.

Electrostatic Interactions Govern "Odd/Even" Effects in Water-Induced Gemini Surfactant Self-Assembly.

Science.gov (United States)

Mantha, Sriteja; McDaniel, Jesse G; Perroni, Dominic V; Mahanthappa, Mahesh K; Yethiraj, Arun

2017-01-26

Gemini surfactants comprise two single-tailed surfactants connected by a linker at or near the hydrophilic headgroup. They display a variety of water-concentration-dependent lyotropic liquid crystal morphologies that are sensitive to surfactant molecular structure and the nature of the headgroups and counterions. Recently, an interesting dependence of the aqueous-phase behavior on the length of the linker has been discovered; odd-numbered linker length surfactants exhibit characteristically different phase diagrams than even-numbered linker surfactants. In this work, we investigate this "odd/even effect" using computer simulations, focusing on experimentally studied gemini dicarboxylates with Na + counterions, seven nonterminal carbon atoms in the tails, and either three, four, five, or six carbon atoms in the linker (denoted Na-73, Na-74, Na-75, and Na-76, respectively). We find that the relative electrostatic repulsion between headgroups in the different morphologies is correlated with the qualitative features of the experimental phase diagrams, predicting destabilization of hexagonal phases as the cylinders pack close together at low water content. Significant differences in the relative headgroup orientations of Na-74 and Na-76 compared to those of Na-73 and Na-75 surfactants lead to differences in linker-linker packing and long-range headgroup-headgroup electrostatic repulsion, which affects the delicate electrostatic balance between the hexagonal and gyroid phases. Much of the fundamental insight presented in this work is enabled by the ability to computationally construct and analyze metastable phases that are not observable in experiments.

Surfactant treatment before reperfusion improves the immediate function of lung transplants in rats

NARCIS (Netherlands)

Erasmus, ME; Petersen, AH; Hofstede, G; Haagsman, HP; Oetomo, SB; Prop, J

An impaired function of alveolar surfactant can cause lung transplant dysfunction early after reperfusion. In this study it was investigated whether treatment with surfactant before reperfusion improves the immediate function of lung transplants and whether an improved transplant function was

Marangoni flows induced by non-uniform surfactant distributions

NARCIS (Netherlands)

Hanyak, M.

2012-01-01

The spreading dynamics of surfactants is of crucial importance for numerous technological applications ranging from printing and coating processes, pulmonary drug delivery to crude oil recovery. In the area of inkjet printing surfactants are necessary for lowering surface tension of water-based ink

Adsorption at the biocompatible α-pinene-water interface and emulsifying properties of two eco-friendly surfactants.

Science.gov (United States)

Trujillo-Cayado, Luis Alfonso; Ramírez, Pablo; Alfaro, María Carmen; Ruíz, Manuela; Muñoz, José

2014-10-01

In this contribution, we provide an accurate characterization at the α-pinene/water interface of two commercial polyoxytheylene glycerol ester surfactants which differ in the number of ethylene oxide (EO) groups, comprising a systematic analysis of interfacial pressure isotherms, dynamic curves, interfacial rheology and emulsifying properties. Polyoxyethylene glycerol esters derived from cocoa oil are non-ionic surfactants obtained from a renewable source which fulfill the environmental and toxicological requirements to be used as eco-friendly emulsifying agents. α-Pinene is a renewable biosolvent completely insoluble in water, which could find numerous applications. Interfacial rheology and equilibrium interfacial pressure data fitted a rigorous reorientation model that assumes that the surfactant molecules, when adsorbed at the interface, can acquire two orientations. The surfactant with the highest number of EO groups (Levenol C201) turned out to be more surface active at the α-pinene/water interface. In addition, the surfactant with the lowest number of EO groups (Levenol H&B) is solubilized into the adjacent oil phase. Slightly concentrated α-pinene emulsions were obtained using both surfactants. Nevertheless, more stable α-pinene emulsions with smaller droplet sizes and lower polidispersity were obtained when Levenol C201 was used as emulsifier instead of Levenol H&B. The systematic characterization presented in this work provides important new findings on the interfacial and emulsifying properties of polyoxytheylene glycerol ester surfactants, which can be applied in the rational development of new biocompatible products. Copyright © 2014 Elsevier B.V. All rights reserved.

Dewetting acrylic polymer films with water/propylene carbonate/surfactant mixtures - implications for cultural heritage conservation.

Science.gov (United States)

Baglioni, M; Montis, C; Brandi, F; Guaragnone, T; Meazzini, I; Baglioni, P; Berti, D

2017-09-13

The removal of hydrophobic polymer films from surfaces is one of the top priorities of modern conservation science. Nanostructured fluids containing water, good solvents for polymers, either immiscible or partially miscible with water, and surfactants have been used in the last decade to achieve controlled removal. The dewetting of the polymer film is often an essential step to achieve efficient removal; however, the role of the surfactant throughout the process is yet to be fully understood. We report on the dewetting of a methacrylate/acrylate copolymer film induced by a ternary mixture of water, propylene carbonate (PC) and C 9-11 E 6 , a nonionic alcohol ethoxylate surfactant. The fluid microstructure was characterised through small angle X-ray scattering and the interactions between the film and water, water/PC and water/PC/C 9-11 E 6 , were monitored through confocal laser-scanning microscopy (CLSM) and analised both from a thermodynamic and a kinetic point of view. The presence of a surfactant is a prerequisite to induce dewetting of μm-thick films at room temperature, but it is not a thermodynamic driver. The amphiphile lowers the interfacial energy between the phases and favors the loss of adhesion of the polymer on glass, decreasing, in turn, the activation energy barrier, which can be overcome by the thermal fluctuations of polymer film stability, initiating the dewetting process.

Hygienic study of barrier function of local water purification facilities in respect to chemical pollutants agrochemicals and surfactants

Energy Technology Data Exchange (ETDEWEB)

Il' in, I E

1984-08-01

Contamination of water reservoirs is presently a multicomponent phenomenon because pesticides, fertilizers, petroleum products, dyes and surfactants may all be present in water. Efficiency of commonly-employed water purification methods was evaluated: sedimentation, chlorination, filtering, and its related effect or representative groups of agricultural chemicals. The most vulnerable link in the rural water purification system was the filtration; in presence of surfactants, the filtration effectiveness was reduced by 40-50%. The effectiveness of this hauling function of surfactants was related to chemical structure of the polluting compounds and to homologous characteristics of the detergents. The effectiveness of the precipitation of chemical impurities from polluted water depended on their solubility in water. 1 figure.

Interactions of a zwitterionic thiophene-based conjugated polymer with surfactants

DEFF Research Database (Denmark)

Costa, Telma; De Azevedo, Diego; Stewart, Beverly

2015-01-01

In this paper we investigate the optical and structural properties of a zwitterionic poly[3-(N-(4-sulfonato-1-butyl)-N,N-diethylammonium)hexyl-2,5-thiophene] (P3SBDEAHT) conjugated polyelectrolyte (CPE) and its interaction in water with surfactants, using absorption, photoluminescence (PL......), electrical conductivity, molecular dynamics simulations (MDS) and small-angle X-ray scattering (SAXS). Different surfactants were studied to evaluate the effect of the head group and chain length on the self-assembly. PL data emphasize the importance of polymer-surfactant electrostatic interactions...... in the formation of complexes. Nevertheless, conductivity and MDS data have shown that nonspecific interactions also play an important role. These seem to be responsible for the spatial position of the surfactant tail in the complex and, eventually, for breaking-up P3SBDEAHT aggregates. SAXS measurements on P3...

A novel biosensor method for surfactant determination based on acetylcholinesterase inhibition

International Nuclear Information System (INIS)

Kucherenko, I S; Soldatkin, O O; Arkhypova, V M; Dzyadevych, S V; Soldatkin, A P

2012-01-01

A novel enzyme biosensor based on acetylcholinesterase inhibition for the determination of surfactants in aqueous solutions is described. Acetylcholinesterase-based bioselective element was deposited via glutaraldehyde on the surface of conductometric transducers. Different variants of inhibitory analysis of surfactants were tested, and finally surfactant's concentration was evaluated by measuring initial rate of acetylcholinesterase inhibition. Besides, we studied the effect of solution characteristics on working parameters of the biosensor for direct measurement of acetylcholine and for inhibitory determination of surfactants. The biosensor's sensitivity to anionic and cationic surfactants (0.35 mg l −1 ) was tested. The high operational stability of the biosensor during determination of acetylcholine (RSD 2%) and surfactants (RSD 11%) was shown. Finally, we discussed the selectivity of the biosensor toward surfactants and other AChE inhibitors. The proposed biosensor can be used as a component of the multibiosensor for ecological monitoring of toxicants. (paper)

Polymer⁻Surfactant System Based Amorphous Solid Dispersion: Precipitation Inhibition and Bioavailability Enhancement of Itraconazole.

Science.gov (United States)

Feng, Disang; Peng, Tingting; Huang, Zhengwei; Singh, Vikramjeet; Shi, Yin; Wen, Ting; Lu, Ming; Quan, Guilan; Pan, Xin; Wu, Chuanbin

2018-04-24

The rapid release of poorly water-soluble drugs from amorphous solid dispersion (ASD) is often associated with the generation of supersaturated solution, which provides a strong driving force for precipitation and results in reduced absorption. Precipitation inhibitors, such as polymers and surfactants, are usually used to stabilize the supersaturated solution by blocking the way of kinetic or thermodynamic crystal growth. To evaluate the combined effect of polymers and surfactants on maintaining the supersaturated state of itraconazole (ITZ), various surfactants were integrated with enteric polymer hydroxypropyl methylcellulose acetate succinate (HPMC AS) to develop polymer⁻surfactant based solid dispersion. The supersaturation stability was investigated by in vitro supersaturation dissolution test and nucleation induction time measurement. Compared to the ASD prepared with HPMC AS alone, the addition of d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) exhibited a synergistic effect on precipitation inhibition. The results indicated that the TPGS not only significantly reduced the degree of supersaturation which is the driving force for precipitation, but also provided steric hindrance to delay crystal growth by absorbing onto the surface of small particles. Subsequently, the formulations were evaluated in vivo in beagle dogs. Compared with commercial product Sporanox ® , the formulation prepared with HPMC AS/TPGS exhibited a 1.8-fold increase in the AUC (0⁻24 h) of ITZ and a 1.43-fold increase of hydroxyitraconazole (OH-ITZ) in the plasma. Similarly, the extent of absorption was increased by more than 40% when compared to the formulation prepared with HPMC AS alone. The results of this study demonstrated that the ASD based on polymer⁻surfactant system could obviously inhibit drug precipitation in vitro and in vivo, which provides a new access for the development of ASD for poorly water-soluble drug.

Surfactant/detergent titration analysis method and apparatus for machine working fluids, surfactant-containing wastewater and the like

Science.gov (United States)

Smith, Douglas D.; Hiller, John M.

1998-01-01

The present invention is an improved method and related apparatus for quantitatively analyzing machine working fluids and other aqueous compositions such as wastewater which contain various mixtures of cationic, neutral, and/or anionic surfactants, soluble soaps, and the like. The method utilizes a single-phase, non-aqueous, reactive titration composition containing water insoluble bismuth nitrate dissolved in glycerol for the titration reactant. The chemical reaction of the bismuth ion and glycerol with the surfactant in the test solutions results in formation of micelles, changes in micelle size, and the formation of insoluble bismuth soaps. These soaps are quantified by physical and chemical changes in the aqueous test solution. Both classical potentiometric analysis and turbidity measurements have been used as sensing techniques to determine the quantity of surfactant present in test solutions. This method is amenable to the analysis of various types of new, in-use, dirty or decomposed surfactants and detergents. It is a quick and efficient method utilizing a single-phase reaction without needing a separate extraction from the aqueous solution. It is adaptable to automated control with simple and reliable sensing methods. The method is applicable to a variety of compositions with concentrations from about 1% to about 10% weight. It is also applicable to the analysis of waste water containing surfactants with appropriate pre-treatments for concentration.

Surfactant/detergent titration analysis method and apparatus for machine working fluids, surfactant-containing wastewater and the like

Science.gov (United States)

Smith, D.D.; Hiller, J.M.

1998-02-24

The present invention is an improved method and related apparatus for quantitatively analyzing machine working fluids and other aqueous compositions such as wastewater which contain various mixtures of cationic, neutral, and/or anionic surfactants, soluble soaps, and the like. The method utilizes a single-phase, non-aqueous, reactive titration composition containing water insoluble bismuth nitrate dissolved in glycerol for the titration reactant. The chemical reaction of the bismuth ion and glycerol with the surfactant in the test solutions results in formation of micelles, changes in micelle size, and the formation of insoluble bismuth soaps. These soaps are quantified by physical and chemical changes in the aqueous test solution. Both classical potentiometric analysis and turbidity measurements have been used as sensing techniques to determine the quantity of surfactant present in test solutions. This method is amenable to the analysis of various types of new, in-use, dirty or decomposed surfactants and detergents. It is a quick and efficient method utilizing a single-phase reaction without needing a separate extraction from the aqueous solution. It is adaptable to automated control with simple and reliable sensing methods. The method is applicable to a variety of compositions with concentrations from about 1% to about 10% weight. It is also applicable to the analysis of waste water containing surfactants with appropriate pre-treatments for concentration. 1 fig.

SP-A-enriched surfactant for treatment of rat lung transplants with SP-A deficiency after storage and reperfusion

NARCIS (Netherlands)

Erasmus, ME; Hofstede, GJH; Petersen, AH; Batenburg, JJ; Haagsman, HP; Oetomo, SB; Prop, J

2002-01-01

Background. The function of pulmonary surfactant is affected by lung transplantation, contributing to impaired lung transplant function. A decreased amount of surfactant protein-A (SP-A) after reperfusion is believed to contribute to the impaired surfactant function. Surfactant treatment has been

Effects of early surfactant treatment persisting for one week after lung transplantation in rats

NARCIS (Netherlands)

Erasmus, ME; Hofstede, GJH; Petersen, AH; Haagsman, HP; Oetomo, SB; Prop, J

We investigated whether pulmonary surfactant in rat lung transplants recovered during the first week post-transplantation, along with symptoms of the reimplantation response, and whether this recovery was affected by early surfactant treatment. The severity of pulmonary injury was varied by

Nanotechnology-based water treatment strategies.

Science.gov (United States)

Kumar, Sandeep; Ahlawat, Wandit; Bhanjana, Gaurav; Heydarifard, Solmaz; Nazhad, Mousa M; Dilbaghi, Neeraj

2014-02-01

The most important component for living beings on the earth is access to clean and safe drinking water. Globally, water scarcity is pervasive even in water-rich areas as immense pressure has been created by the burgeoning human population, industrialization, civilization, environmental changes and agricultural activities. The problem of access to safe water is inevitable and requires tremendous research to devise new, cheaper technologies for purification of water, while taking into account energy requirements and environmental impact. This review highlights nanotechnology-based water treatment technologies being developed and used to improve desalination of sea and brackish water, safe reuse of wastewater, disinfection and decontamination of water, i.e., biosorption and nanoadsorption for contaminant removal, nanophotocatalysis for chemical degradation of contaminants, nanosensors for contaminant detection, different membrane technologies including reverse osmosis, nanofiltration, ultrafiltration, electro-dialysis etc. This review also deals with the fate and transport of engineered nanomaterials in water and wastewater treatment systems along with the risks associated with nanomaterials.

Simultaneous determination of three surfactants and water in shampoo and liquid soap by ATR-FTIR.

Science.gov (United States)

Carolei, Luciano; Gutz, Ivano G R

2005-03-31

It is demonstrated for the first time that the principal constituents of a shampoo as well as of a liquid soap -three surfactants and water- can be determined directly, simultaneously and quickly in undiluted samples by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy in the middle infrared region, despite the broad absorption bands of the solvent. Two of the surfactants, sodium lauryl ether sulfate (SLES) and cocoamidopropyl betaine (CAPB), are common to both formulations; alkylpolyglucoside (APG) is the third surfactant of the liquid soap and cocodiethanolamide (CDEA), the corresponding ingredient of the shampoo. Absorbance data of the undiluted samples and of the calibration standards was collected in the middle infrared region of the spectrum (800-1600 and 1900-3000cm(-1)). Two methods of multivariate quantification were compared: classical least squares (CLS), where absorbance data measured at 200 wavenumbers was processed, and inverse least squares (ILS), where data at 10 selected wavenumbers was analyzed. A spectra normalization procedure, based on a dominating water band, was examined. Twenty-seven standard mixtures were used for each application, consisting of all combinations at three concentration levels of each surfactant, respectively the lower limit, the expected value and the upper limit accepted in quality control. By favoring wavenumbers where absorption bands of the minor components (APG in the liquid soap and CDEA in the shampoo) are more intense, good results were obtained for 18 simulated samples of shampoo and 18 samples of liquid soap, no matter if calculations were made by CLS or ILS. The relative errors for water (major component, 84-88%) and SLES (7-10%) were always below 2%; for CAPB (2-4%), APG (<2%) and CDEA (<2%), they occasionally reached 5% of the component, an uncertainty of less than 0.07% in terms of the sample weight.

The Effect Of Organic Surfactants On The Properties Of Common Hygroscopic Particles: Effective Densities, Reactivity And Water Evaporation Of Surfactant Coated Particles

Science.gov (United States)

Cuadrarodriguez, L.; Zelenyuk, A.; Imre, D.; Ellison, B.

2006-12-01

Measurements of atmospheric aerosol compositions routinely show that organic compounds account for a very large fraction of the particle mass. The organic compounds that make up this aerosol mass represent a wide range of molecules with a variety of properties. Many of the particles are composed of hygroscopic salts like sulfates, nitrates and sea-salt internally mixed with organics. While the properties of the hygroscopic salts are known, the effect of the organic compounds on the microphysical and chemical properties which include CCN activity is not clear. .One particularly interesting class of internally mixed particles is composed of aqueous salts solutions that are coated with organic surfactants which are molecules with long aliphatic chain and a water soluble end. Because these molecules tend to coat the particles' surfaces, a monolayer might be sufficient to drastically alter their hygroscopic properties, their CCN activity, and reactivity. The aliphatic chains, being exposed to the oxidizing atmosphere are expected to be transformed through heterogeneous chemistry, yielding complex products with mixed properties. We will report the results from a series of observations on ammonium sulfate, sodium chloride and sea salt particles coated with three types of surfactant molecules: sodium lauryl sulfate, sodium oleate and laurtrimonium chloride. We have been able to measure the effective densities of internally mixed particles with a range of surfactant concentration that start below a monolayer and extend all the way to particles composed of pure surfactant. For many of the measurements the data reveal a rather complex picture that cannot be simply interpreted in terms of the known pure-compound densities. For unsaturated hydrocarbons we observed and quantified the effect of oxidation by ozone on particle size, effective density and individual particle mass spectral signatures. One of the more important properties of these surfactants is that they can form a

The Determination of Anionic Surfactants in Natural and Waste Waters.

Science.gov (United States)

Crisp, P. T.; And Others

1983-01-01

Background information, procedures, and results of an experiment suitable for measuring subpart per million concentrations of anionic surfactants in natural waters and waste effluents are provided. The experiment required only a spectrophotometer or filter photometer and has been successfully performed by students in an undergraduate environmental…

SCREENING METHODS FOR SELECTION OF SURFACTANT FORMULATIONS FOR IOR FROM FRACTURED CARBONATE RESERVOIRS

Energy Technology Data Exchange (ETDEWEB)

William A. Goddard III; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu; Seung Soon Jang

2005-07-01

This topical report presents details of the laboratory work performed to complete Task 1 of this project; developing rapid screening methods to assess surfactant performance for IOR (Improved Oil Recovery) from fractured carbonate reservoirs. The desired outcome is to identify surfactant formulations that increase the rate and amount of aqueous phase imbibition into oil-rich, oil-wet carbonate reservoir rock. Changing the wettability from oil-wet to water-wet is one key to enhancing this water-phase imbibition process that in turn recovers additional oil from the matrix portion of a carbonate reservoir. The common laboratory test to evaluate candidate surfactant formulations is to measure directly the aqueous imbibition rate and oil recovery from small outcrop or reservoir cores, but this procedure typically requires several weeks. Two methods are presented here for the rapid screening of candidate surfactant formulations for their potential IOR performance in carbonate reservoirs. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite power is pre-treated to make the surface oil-wet. The next step is to add the pre-treated powder to a test tube and add a candidate aqueous surfactant formulation; the greater the percentage of the calcite that now sinks to the bottom rather than floats, the more effective the surfactant is in changing the solids to become now preferentially water-wet. Results from the screening test generally are consistent with surfactant performance reported in the literature.

Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater

International Nuclear Information System (INIS)

Hwang, Sangchul; Martinez, Diana; Perez, Priscilla; Rinaldi, Carlos

2011-01-01

This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENP Fe-surf ) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that ∼8.7% of ENP Fe-surf applied were present in the effluent stream. The stable presence of ENP Fe-surf was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENP Fe-surf deteriorated the effluent water quality at a statistically significant level (p Fe-surf would be introduced into environmental receptors through the treated effluent and could potentially impact them. - Highlights: → Surfactant-coated engineered iron oxide nanoparticles (ENP Fe-surf ) were assessed. → Effluent quality was analyzed from a sequencing batch reactor with ENP Fe-surf . → ∼8.7% of ENP Fe-surf applied was present in the effluent. → ENP Fe-surf significantly (p Fe-surf will be introduced into environmental receptors. - Stable presence of surfactant-coated engineered iron oxides nanoparticles deteriorated the effluent water quality at a statistically significant level (p < 0.05).

Plasma-based water treatment: development of a general mechanistic model to estimate the treatability of different types of contaminants

International Nuclear Information System (INIS)

Mededovic Thagard, Selma; Stratton, Gunnar R; Paek, Eunsu; Dai, Fei; Holsen, Thomas M; Bellona, Christopher L; Bohl, Douglas G; Dickenson, Eric R V

2017-01-01

To determine the types of applications for which plasma-based water treatment (PWT) is best suited, the treatability of 23 environmental contaminants was assessed through treatment in a gas discharge reactor with argon bubbling, termed the enhanced-contact reactor. The contaminants were treated in a mixture to normalize reaction conditions and convective transport limitations. Treatability was compared in terms of the observed removal rate constant ( k obs ). To characterize the influence of interfacial processes on k obs , a model was developed that accurately predicts k obs for each compound, as well as the contributions to k obs from each of the three general degradation mechanisms thought to occur at or near the gas–liquid interface: ‘sub-surface’, ‘surface’ and ‘above-surface’. Sub-surface reactions occur just underneath the gas–liquid interface between the contaminants and dissolved plasma-generated radicals, contributing significantly to the removal of compounds that lack surfactant-like properties and so are not highly concentrated at the interface. Surface reactions occur at the interface between the contaminants and dissolved radicals, contributing significantly to the removal of surfactant-like compounds that have high interfacial concentrations. The contaminants’ interfacial concentrations were calculated using surface-activity parameters determined through surface tension measurements. Above-surface reactions are proposed to take place in the plasma interior between highly energetic plasma species and exposed portions of compounds that extend out of the interface. This mechanism largely accounts for the degradation of surfactant-like contaminants that contain highly hydrophobic perfluorocarbon groups, which are most likely to protrude from the interface. For a few compounds, the degree of exposure to the plasma interior was supported by new and previously reported molecular dynamics simulations results. By reviewing the predicted

Microemulsion-based lycopene extraction: Effect of surfactants, co-surfactants and pretreatments.

Science.gov (United States)

Amiri-Rigi, Atefeh; Abbasi, Soleiman

2016-04-15

Lycopene is a potent antioxidant that has received extensive attention recently. Due to the challenges encountered with current methods of lycopene extraction using hazardous solvents, industry calls for a greener, safer and more efficient process. The main purpose of present study was application of microemulsion technique to extract lycopene from tomato pomace. In this respect, the effect of eight different surfactants, four different co-surfactants, and ultrasound and enzyme pretreatments on lycopene extraction efficiency was examined. Experimental results revealed that application of combined ultrasound and enzyme pretreatments, saponin as a natural surfactant, and glycerol as a co-surfactant, in the bicontinuous region of microemulsion was the optimal experimental conditions resulting in a microemulsion containing 409.68±0.68 μg/glycopene. The high lycopene concentration achieved, indicates that microemulsion technique, using a low-cost natural surfactant could be promising for a simple and safe separation of lycopene from tomato pomace and possibly from tomato industrial wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Energy Technology Data Exchange (ETDEWEB)

Lynn E. Katz; Kerry A. Kinney; R. S. Bowman; E. J. Sullivan

2004-03-11

This report summarizes work of this project from October 2003 through March 2004. The major focus of the research was to further investigate BTEX removal from produced water, to quantify metal ion removal from produced water, and to evaluate a lab-scale vapor phase bioreactor (VPB) for BTEX destruction in off-gases produced during SMZ regeneration. Batch equilibrium sorption studies were conducted to evaluate the effect of semi-volatile organic compounds commonly found in produced water on the sorption of benzene, toluene, ethylbenzene, and xylene (BTEX) onto surfactant-modified zeolite (SMZ) and to examine selected metal ion sorption onto SMZ. The sorption of polar semi-volatile organic compounds and metals commonly found in produced water onto SMZ was also investigated. Batch experiments were performed in a synthetic saline solution that mimicked water from a produced water collection facility in Wyoming. Results indicated that increasing concentrations of semi-volatile organic compounds increased BTEX sorption. The sorption of phenol compounds could be described by linear isotherms, but the linear partitioning coefficients decreased with increasing pH, especially above the pKa's of the compounds. Linear correlations relating partitioning coefficients of phenol compounds with their respective solubilities and octanol-water partitioning coefficients were developed for data collected at pH 7.2. The sorption of chromate, selenate, and barium in synthetic produced water were also described by Langmuir isotherms. Experiments conducted with a lab-scale vapor phase bioreactor (VPB) packed with foam indicated that this system could achieve high BTEX removal efficiencies once the nutrient delivery system was optimized. The xylene isomers and benzene were found to require the greatest biofilter bed depth for removal. This result suggested that these VOCs would ultimately control the size of the biofilter required for the produced water application. The biofilter

Gels and lyotropic liquid crystals: using an imidazolium-based catanionic surfactant in binary solvents.

Science.gov (United States)

Cheng, Ni; Hu, Qiongzheng; Bi, Yanhui; Xu, Wenwen; Gong, Yanjun; Yu, Li

2014-08-05

The self-assembly behavior of an imidazolium-based catanionic surfactant, 1-butyl-3-methylimidazolium dodecylsulfate ([C4mim][C12H25SO4]), was investigated in water-ethylammonium nitrate (EAN) mixed solvents with different volume ratios. It is particular interesting that this simple surfactant could not only form lyotropic liquid crystals (LLC) with multimesophases, i.e., normal hexagonal (H1), lamellar liquid crystal (Lα), and reverse bicontinuous cubic phase (V2), in the water-rich environment but also act as an efficient low-molecular-weight gelator (LMWG) which gelated EAN-abundant binary media in a broad concentration range. The peculiar nanodisk cluster morphology of gels composed of similar bilayer units was first observed. FT-IR spectra and density functional theory (DFT) calculations reveal that strong H bonding and electrostatic interactions between EAN and the headgroups of [C4mim][C12H25SO4] are primarily responsible for gelation. The self-assembled gels displayed excellent mechanical strength and a thermoreversible sol-gel transition. It is for the first time that a rich variety of controllable ordered aggregates could be observed only by simply modulating the concentration of a single imidazolium-based catanionic surfactant or the ratio of mixed solvents. This environmentally friendly system is expected to have broad applications in various fields, such as materials science, drug delivery systems, and supramolecular chemistry.

Adsorption of anionic surfactants in limestone medium during oil recovery

Energy Technology Data Exchange (ETDEWEB)

Canbolat, Serhat; Bagci, Suat [Middle East Technical Univ., Dept. of Petroleum and Natural Gas Engineering, Ankara (Turkey)

2004-07-15

Foam-forming surfactant performance was evaluated by several experimental methods (interfacial tension, foam stability, corefloods) using commercial surfactants. There is considerable interest in the use of foam-forming surfactants for mobility control in water flood. To provide effective mobility control, the injected surfactant must propagate from the injection well toward the production well. One of the important parameters affecting propagation of foam-forming surfactant through the reservoir is the retention of surfactant due to its adsorption on reservoir rock. The determination of the adsorption of foam-forming surfactants in limestone reservoirs is important for the residual oil recovery efficiency. Adsorption measurements, recovery efficiencies, and surfactant and alkaline flooding experiments carried out with the representative of the selected surfactants alkaline solutions, linear alkyl benzene sulphonic acid (LABSA), sodium lauryl ether sulfate (SLES), and NaOH in a limestone medium. These surfactants were selected with respect to their foaming ability. Calibration curves formed by pH measurements were used to determine the correct adsorption amount of the used surfactants and recovery efficiency of these surfactants compared with base waterflooding. The results showed that LABSA adsorbed more than SLES in limestone reservoirs. The recovery efficiency of SLES was higher than the recovery efficiency of LABSA, and they decreased the recovery efficiency with respect to only the water injection case. (Author)

Effects of gamma radiation from 60Co on dilute aqueous solutions of Linear Alkyl Sulfonate Surfactants and other organic pollutants

International Nuclear Information System (INIS)

Rohrer, D.M.

1975-01-01

This study is the result of research findings and operational experiences gained by the author in over four years of work associated with the use of 60 Co for the treatment of waste-water. The effects of 60 Co are discussed with regard to radiochemical destruction of specific organic pollutant species. The study deals specifically with the effects of gamma radiation from a 30,000 Ci 60 Co source upon aqueous solutions of Linear Alkyl Sulfonate Surfactants. The new Linear Alkyl Sulfonate (LAS) Surfactants, the major surfactant produced in the United States of America since June 1965, was developed to replace the old Alkyl Benzene Sulfonate (ABS) Surfactants. The reason for the removal of Alkyl Benzene Sulfonate Surfactants was their extreme environmental stability and the associated appearance of foam in waste-water treatment plants and receiving streams. Although the Linear Alkyl Sulfonate Surfactants are considered 'bio-degradable', the time required for 'bio-degradation' is impractical within the present environmental guidelines. This led to research into alternate techniques of treatment for the destruction of Linear Alkyl Sulfonate Surfactants. Consideration is also given to similar effects of gamma radiation upon pesticides and to the practical aspects of the use of gamma radiation for the treatment of waste-water. Included are discussions of the general experimental procedures used, the sources and their calibration, and sampling techniques to ensure the accuracy of the data. (author)

[Techniques and complementary techniques. Complementary treatments: nitric oxide, prone positioning and surfactant].

Science.gov (United States)

Martos Sánchez, I; Vázquez Martínez, J L; Otheo de Tejada, E; Ros, P

2003-11-01

The management of hypoxic respiratory failure is based on oxygen delivery and ventilatory support with lung-protective ventilation strategies. Better understanding of acute lung injury have led to new therapeutic approaches that can modify the outcome of these patients. These adjunctive oxygenation strategies include inhaled nitric oxide and surfactant delivery, and the use of prone positioning. Nitric oxide is a selective pulmonary vasodilator that when inhaled, improves oxygenation in clinical situations such as persistent pulmonary hypertension of the newborn, pulmonary hypertension associated with congenital heart disease, and acute respiratory distress syndrome (ARDS). When applied early in ARDS, prone positioning improves distribution of ventilation and reduces the intrapulmonary shunt. The surfactant has dramatically decreased mortality caused by hyaline membrane disease in premature newborns, although the results have been less successful in ARDS. Greater experience is required to determine whether the combination of these treatments will improve the prognosis of these patients.

Theoretical and Simulations-Based Modeling of Micellization in Linear and Branched Surfactant Systems

Science.gov (United States)

Mendenhall, Jonathan D.

Surfactants are chemically-heterogeneous molecules possessing hydrophilic (head) and hydrophobic (tail) moieties. This dual nature of surfactants leads to interesting phase behavior in aqueous solution as a function of surfactant concentration, including: (i) formation of surfactant monolayers at surfaces and interfaces, and (ii) self-assembly into finite aggregates (micelles) in the bulk solution beyond the critical micelle concentration (cmc). This concentration-dependent phase behavior induces changes in solution properties. For example, the surface activity of surfactants can decrease the surface tension, and self-assembly in bulk solution can lead to changes in viscosity, equivalent conductivity, solubilization capacity, and other bulk properties. These effects make surfactants quite attractive and unique for use in product formulations, where they are utilized as detergents, dispersants, emulsifiers, solubilizers, surface and interfacial tension modifiers, and in other contexts. The specific chemical structure of the surfactant head and tail is essential in determining the overall performance properties of a surfactant in aqueous media. The surfactant tail drives the self-assembly process through the hydrophobic effect, while the surfactant head imparts a certain extent of solubility to the surfactant in aqueous solution through preferential interactions with the hydrogen-bonding network of water. The interplay between these two effects gives rise to the particular phase diagram of a surfactant, including the specific cmc at which micelles begin to form. In addition to serving as a quantitative indicator of micelle formation, the cmc represents a limit to surface monolayer formation, and hence to surface and interfacial tension reduction, because surfactant adsorption at interfaces remains approximately constant beyond the cmc. In addition, the cmc represents the onset of changes in bulk solution properties. This Thesis is concerned with the prediction of cmc

Characterization of hydraulic fracturing flowback water in Colorado: implications for water treatment.

Science.gov (United States)

Lester, Yaal; Ferrer, Imma; Thurman, E Michael; Sitterley, Kurban A; Korak, Julie A; Aiken, George; Linden, Karl G

2015-04-15

A suite of analytical tools was applied to thoroughly analyze the chemical composition of an oil/gas well flowback water from the Denver-Julesburg (DJ) basin in Colorado, and the water quality data was translated to propose effective treatment solutions tailored to specific reuse goals. Analysis included bulk quality parameters, trace organic and inorganic constituents, and organic matter characterization. The flowback sample contained salts (TDS=22,500 mg/L), metals (e.g., iron at 81.4 mg/L) and high concentration of dissolved organic matter (DOC=590 mgC/L). The organic matter comprised fracturing fluid additives such as surfactants (e.g., linear alkyl ethoxylates) and high levels of acetic acid (an additives' degradation product), indicating the anthropogenic impact on this wastewater. Based on the water quality results and preliminary treatability tests, the removal of suspended solids and iron by aeration/precipitation (and/or filtration) followed by disinfection was identified as appropriate for flowback recycling in future fracturing operations. In addition to these treatments, a biological treatment (to remove dissolved organic matter) followed by reverse osmosis desalination was determined to be necessary to attain water quality standards appropriate for other water reuse options (e.g., crop irrigation). The study provides a framework for evaluating site-specific hydraulic fracturing wastewaters, proposing a suite of analytical methods for characterization, and a process for guiding the choice of a tailored treatment approach. Copyright © 2015 Elsevier B.V. All rights reserved.

Photoassisted Electrochemical Treatment of Azo and Phtalocyanine Reactive Dyes in the Presence of Surfactants

Science.gov (United States)

Sala, Mireia; López-Grimau, Víctor; Gutiérrez-Bouzán, Carmen

2016-01-01

An electrochemical treatment (EC) was applied at different intensities to degrade the chromophoric groups of dyes C.I. Reactive Black 5 (RB5) and C.I. Reactive Blue 7 (Rb7) until uncolored species were obtained. Decolorization rate constants of the azo dye RB5 were higher than the phtalocyanine Rb7 ones. In addition, the EC treatment was more efficient at higher intensities, but these conditions significantly increased the generation of undesirable by-products such as chloroform. The combination of EC with UV irradiation (UVEC) drastically minimized the generation of chloroform. The photo-assisted electrochemical treatment was also able to achieve decolorization values of 99%. Finally, mixtures of dyes and surfactants were treated by EC and UVEC. In the presence of surfactants, the decolorization kinetic of dyes was slowed due to the competitive reactions of surfactants degradation. Both methods achieved total decolorization and in both cases, the generation of haloforms was negligible. PMID:28773335

Effect of surfactant and surfactant blends on pseudoternary phase diagram behavior of newly synthesized palm kernel oil esters

Directory of Open Access Journals (Sweden)

Mahdi ES

2011-06-01

Full Text Available Elrashid Saleh Mahdi1, Mohamed HF Sakeena1, Muthanna F Abdulkarim1, Ghassan Z Abdullah1,3, Munavvar Abdul Sattar2, Azmin Mohd Noor11Department of Pharmaceutical Technology, 2Department of Physiology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia; 3Department of Pharmaceutical Technology, International Medical University, Bukit Jalil, Kuala Lumpur, MalaysiaBackground: The purpose of this study was to select appropriate surfactants or blends of surfactants to study the ternary phase diagram behavior of newly introduced palm kernel oil esters.Methods: Nonionic surfactant blends of Tween® and Tween®/Span® series were screened based on their solubilization capacity with water for palm kernel oil esters. Tween® 80 and five blends of Tween® 80/Span® 80 and Tween® 80/Span® 85 in the hydrophilic-lipophilic balance (HLB value range of 10.7–14.0 were selected to study the phase diagram behavior of palm kernel oil esters using the water titration method at room temperature.Results: High solubilization capacity was obtained by Tween® 80 compared with other surfactants of Tween® series. High HLB blends of Tween® 80/Span® 85 and Tween® 80/Span® 80 at HLB 13.7 and 13.9, respectively, have better solubilization capacity compared with the lower HLB values of Tween® 80/Span® 80. All the selected blends of surfactants were formed as water-in-oil microemulsions, and other dispersion systems varied in size and geometrical layout in the triangles. The high solubilization capacity and larger areas of the water-in-oil microemulsion systems were due to the structural similarity between the lipophilic tail of Tween® 80 and the oleyl group of the palm kernel oil esters.Conclusion: This study suggests that the phase diagram behavior of palm kernel oil esters, water, and nonionic surfactants is not only affected by the HLB value, but also by the structural similarity between palm kernel oil esters and the surfactant

Ceramic membrane fouling during ultrafiltration of oil/water emulsions: roles played by stabilization surfactants of oil droplets.

Science.gov (United States)

Lu, Dongwei; Zhang, Tao; Ma, Jun

2015-04-07

Oil/water (O/W) emulsion stabilized by surfactants is the part of oily wastewater that is most difficult to handle. Ceramic membrane ultrafiltration presently is an ideal process to treat O/W emulsions. However, little is known about the fouling mechanism of the ceramic membrane during O/W emulsion treatment. This paper investigated how stabilization surfactants of O/W emulsions influence the irreversible fouling of ceramic membranes during ultrafiltration. An unexpected phenomenon observed was that irreversible fouling was much less when the charge of the stabilization surfactant of O/W emulsions is opposite to the membrane. The less ceramic membrane fouling in this case was proposed to be due to a synergetic steric effect and demulsification effect which prevented the penetration of oil droplets into membrane pores and led to less pore blockage. This proposed mechanism was supported by cross section images of fouled and virgin ceramic membranes taken with scanning electron microscopy, regression results of classical fouling models, and analysis of organic components rejected by the membrane. Furthermore, this mechanism was also verified by the existence of a steric effect and demulsification effect. Our finding suggests that ceramic membrane oppositely charged to the stabilization surfactant should be applied in ultrafiltration of O/W emulsions to alleviate irreversible membrane fouling. It could be a useful rule for ceramic membrane ultrafiltration of oily wastewater.

Ceramic membrane fouling during ultrafiltration of oil/water emulsions: Roles played by stabilization surfactants of oil droplets

KAUST Repository

Lu, Dongwei

2015-04-07

Oil/water (O/W) emulsion stabilized by surfactants is the part of oily wastewater that is most difficult to handle. Ceramic membrane ultrafiltration presently is an ideal process to treat O/W emulsions. However, little is known about the fouling mechanism of the ceramic membrane during O/W emulsion treatment. This paper investigated how stabilization surfactants of O/W emulsions influence the irreversible fouling of ceramic membranes during ultrafiltration. An unexpected phenomenon observed was that irreversible fouling was much less when the charge of the stabilization surfactant of O/W emulsions is opposite to the membrane. The less ceramic membrane fouling in this case was proposed to be due to a synergetic steric effect and demulsification effect which prevented the penetration of oil droplets into membrane pores and led to less pore blockage. This proposed mechanism was supported by cross section images of fouled and virgin ceramic membranes taken with scanning electron microscopy, regression results of classical fouling models, and analysis of organic components rejected by the membrane. Furthermore, this mechanism was also verified by the existence of a steric effect and demulsification effect. Our finding suggests that ceramic membrane oppositely charged to the stabilization surfactant should be applied in ultrafiltration of O/W emulsions to alleviate irreversible membrane fouling. It could be a useful rule for ceramic membrane ultrafiltration of oily wastewater. © 2015 American Chemical Society.

Wetting kinetics of water nano-droplet containing non-surfactant nanoparticles: A molecular dynamics study

International Nuclear Information System (INIS)

Lu, Gui; Hu, Han; Sun, Ying; Duan, Yuanyuan

2013-01-01

In this Letter, dynamic wetting of water nano-droplets containing non-surfactant gold nanoparticles on a gold substrate is examined via molecular dynamics simulations. The results show that the addition of non-surfactant nanoparticles hinders the nano-second droplet wetting process, attributed to the increases in both surface tension of the nanofluid and friction between nanofluid and substrate. The droplet wetting kinetics decreases with increasing nanoparticle loading and water-particle interaction energy. The observed wetting suppression and the absence of nanoparticle ordering near the contact line of nano-sized droplets differ from the wetting behaviors reported from nanofluid droplets of micron size or larger

Adsorption behavior of hydrophobin and hydrophobin/surfactant mixtures at the air-water interface.

Science.gov (United States)

Zhang, Xiaoli L; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Bent, Julian; Cox, Andrew; Campbell, Richard A

2011-09-20

The adsorption of the surface-active protein hydrophobin, HFBII, and the competitive adsorption of HFBII with the cationic, anionic, and nonionic surfactants hexadecyltrimethylammonium bromide, CTAB, sodium dodecyl sulfate, SDS, and hexaethylene monododecyl ether, C(12)E(6), has been studied using neutron reflectivity, NR. HFBII adsorbs strongly at the air-water interface to form a dense monolayer ∼30 Å thick, with a mean area per molecule of ∼400 Å(2) and a volume fraction of ∼0.7, for concentrations greater than 0.01 g/L, and the adsorption is independent of the solution pH. In competition with the conventional surfactants CTAB, SDS, and C(12)E(6) at pH 7, the HFBII adsorption totally dominates the surface for surfactant concentrations less than the critical micellar concentration, cmc. Above the cmc of the conventional surfactants, HFBII is displaced by the surfactant (CTAB, SDS, or C(12)E(6)). For C(12)E(6) this displacement is only partial, and some HFBII remains at the surface for concentrations greater than the C(12)E(6) cmc. At low pH (pH 3) the patterns of adsorption for HFBII/SDS and HFBII/C(12)E(6) are different. At concentrations just below the surfactant cmc there is now mixed HFBII/surfactant adsorption for both SDS and C(12)E(6). For the HFBII/SDS mixture the structure of the adsorbed layer is more complex in the region immediately below the SDS cmc, resulting from the HFBII/SDS complex formation at the interface. © 2011 American Chemical Society

Adsorption Of Surfactants At the Water-Oil Interface By Short-Time Diffusion

Science.gov (United States)

Cortes-Estrada, Aldo; Ibarra-Bracamontes, Laura; Aguilar-Corona, Alicia; Viramontes-Gamboa, Gonzalo

2017-11-01

Surface tension is an important parameter for different industrial processes. The addition of surfactants can modify the interfacial tension between two fluids. As the surfactant molecules reach and are adsorbed at a fluid interface, the surface tension or interfacial tension is reduced until the interface is saturated. Dynamic Interfacial tension measurements were carried out using an optical tensiometer by the Pendant Drop technique at a room temperature of 25 °C for a period of 250 sec. A drop of surfactant solution was deposited and allowed to diffuse into a water-oil interface, and then the adsorption rate at the interface was calculated. Sodium Dodecyl Sulfate (SDS) was used as the surfactant, hexane and dodecane were tested as the oil phase. A linear decay in the interfacial tension was observed for the lower initial concentrations of the order of 0.0001 to 0.01 mM, and an exponential decay was observed for initial concentrations of the order of 0.1 to 1 mM. This study was supported by the Mexican Council of Science and Technology (CONACyT) and by the Scientific Research Coordination of the University of Michoacan in Mexico.

Aerobic biodegradation of amphoteric amine-oxide-based surfactants: Effect of molecular structure, initial surfactant concentration and pH.

Science.gov (United States)

Ríos, Francisco; Lechuga, Manuela; Fernández-Serrano, Mercedes; Fernández-Arteaga, Alejandro

2017-03-01

The present study was designed to provide information regarding the effect of the molecular structure of amphoteric amine-oxide-based surfactants and the initial surfactant concentration on their ultimate biodegradation. Moreover, given this parameter's pH-dependence, the effect of pH was also investigated. Three amine-oxide-based surfactants with structural differences in their hydrophobic alkyl chain were tested: Lauramine oxide (AO-R 12 ), Myristamine oxide (AO-R 14 ) and Cocamidopropylamine oxide (AO-Cocoamido). We studied the ultimate biodegradation using the Modified OECD Screening Test at initial surfactant concentrations ranged from 5 to 75 mg L -1 and at pH levels from 5 to 7.4. The results demonstrate that at pH 7.4, amine-oxide-based surfactants are readily biodegradable. In this study, we concluded that ω-oxidation can be assumed to be the main biodegradation pathway of amine-oxides and that differences in the biodegradability between them can be explained by the presence of an amide group in the alkyl chain of AO-Cocoamido; the CN fission of the amide group slows down their mineralization process. In addition, the increase in the concentration of the surfactant from 5 to 75 mg L -1 resulted in an increase in the final biodegradation of AO-R 12 and AO-R 14 . However, in the case of AO-Cocoamido, a clear relationship between the concentration and biodegradation cannot be stated. Conversely, the biodegradability of AO-R 12 and AO-R 14 was considerably lower in an acid condition than at a pH of 7.4, whereas AO-Cocoamido reached similar percentages in acid conditions and at a neutral pH. However, microorganisms required more time to acclimate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Possibility of ozone application in purification of waste water of NPP special laundries from surfactants

International Nuclear Information System (INIS)

Grachok, M.A.; Prokudina, S.A.; Permyakov, V.G.; Shulyat'ev, M.I.

1992-01-01

The influence of the medium pH, temperature, rate of ozone-air mixture (OAM) feed on ozonation rate of model solutions and actual sewage waters of Kursk NPP was studied. It is shown that pH≤11, 60, 50 deg C and OAM feed rate of 50 l/h are the optimal conditions of solutions of sewage waters of specialized laundry at Kursk NPP. Specific consumption of ozone for surfactant destruction (OP-10 and Kristall synthetic detergent) under the conditions mentioned was determined. The investigations show that preliminary ozonation of sewage waters to remove surfactants increases considerably the efficiency of evaporator operation, improves the quality of condensate and prolongs service life of ion-exchange filters

Partitioning of hexachlorobenzene in a kaolin/humic acid/surfactant/water system: Combined effect of surfactant and soil organic matter

Energy Technology Data Exchange (ETDEWEB)

Wan, Jinzhong; Wang, Lingling [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu, Xiaohua, E-mail: hust-esri2009@hotmail.com [Environmental Science Research Institute, Huazhong University of Science and Technology, Wuhan 430074 (China); Lin, Yusuo; Zhang, Shengtian [Nanjing Institute of Environmental Science, Ministry of Environmental Protection of China, Nanjing 210042 (China)

2011-11-30

Highlights: Black-Right-Pointing-Pointer We study HCB partitioning in a kaolin/humic acid/TX100/water system. Black-Right-Pointing-Pointer We reveal influence of TX100-HA interaction on TX100 and HA sorption to kaolin. Black-Right-Pointing-Pointer We verify combined effect of TX100 and HA on HCB desorption from clay. - Abstract: Understanding the combined effect of soil organic matter (SOM) and surfactants on the partitioning of hydrophobic organic compounds in soil/water systems is important to predict the effectiveness of surfactant-enhanced remediation (SER). In the present study we investigate the partitioning of hexachlorobenzene (HCB) within a humic acid (HA)-coated kaolin/Triton X-100 (TX100)/water system, with special emphasis on the interaction between TX100 and HA, and their combined effect on HCB sorption. HA firstly enhanced then suppressed TX100 sorption to kaolin as the amounts of HA increased, while the addition of TX100 led to a consistent reduction in HA sorption. In the HA-coated kaolin/TX100/water system, TX100 played a primary role in enhancing desorption of HCB, while the role could be suppressed and then enhanced as HA coating amounts increased. Only at HA coating above 2.4%, dissolved HA outcompeted clay-bound HA for HCB partitioning, resulting in dissolved HA enhanced desorption. The presence of dissolved HA at these conditions further promoted the effectiveness of TX100 enhanced desorption. Despite a reduced TX100 sorption to clay was achieved due to the presence of dissolved HA, the effect on HCB desorption was comparatively slight. A reliable cumulative influence of HA and TX100 on HCB desorption was observed, although HCB desorption by HA/TX100 mixed was less than the sum of HA and TX100 individually. Our study suggests that for soils of high organic contents, the combined effect of SOM and surfactants on HOCs desorption can be applied to improve the performance of SER.

Thermodynamic and Interfacial Properties of DTABr/CTABr Mixed Surfactant Systems in Ethanolamine/Water Mixtures: A Conductometry Study

OpenAIRE

Esan, Olaseni Segun; Osundiya, Medinat Olubunmi; Aboluwoye, Christopher Olumuyiwa; Olanrewaju, Owoyomi; Ige, Jide

2013-01-01

Mixed-micelle formation in the binary mixtures of dodecyltrimethylammonium bromide (DTABr) and cetyltrimethylammonium bromide (CTABr) surfactants in water-ethanolamine mixed solvent systems has been studied by conductometric method in the temperature range of 298.1 to 313.1 K at 5 K intervals. It was observed that the presence of ethanolamine forced the formation of mixed micelle to lower total surfactant concentration than in water only. The synergistic interaction was quantitatively investi...

Effect of non-homogeneous spatial distributions of surfactants on the stability of high-content bitumen-in-water emulsions

International Nuclear Information System (INIS)

Urbina-Villalba, German; Garcia-Sucre, Maximo

2000-01-01

In order to study the effects of non-homogeneous spatial distributions of surfactants on the drop size of high-content bitumen-in-water emulsions, a modification of a standard Brownian Dynamics algorithm was employed. The new algorithm is able to simulate the evolution of oil/water emulsions towards flocculation and coalescence. The simulation boxes contain 216 and 125 particles initially distributed in a homogeneous simple cubic arrangement, corresponding to bitumen/water volume fractions of 0.30 and 0.51, respectively. The particles interact through a DLVO potential dependent on the total surfactant concentration, spatial surfactant distribution, and the amount of surfactant adsorbed to the bitumen/water interface. As will be shown in this article, certain combinations of the referred variables can produce a wide variety of repulsive potentials between similar drops. The variation of the total number of drops with time does not obey the usual analytical formalisms developed for more diluted cases, and instead, a simple exponential decrease of the number of drops with time is found. Such behavior has already been confirmed by experiment. Some similarities between the present results and those previously published for more diluted systems are discussed [es

Micelles as Soil and Water Decontamination Agents.

Science.gov (United States)

Shah, Afzal; Shahzad, Suniya; Munir, Azeema; Nadagouda, Mallikarjuna N; Khan, Gul Shahzada; Shams, Dilawar Farhan; Dionysiou, Dionysios D; Rana, Usman Ali

2016-05-25

Contaminated soil and water pose a serious threat to human health and ecosystem. For the treatment of industrial effluents or minimizing their detrimental effects, preventive and remedial approaches must be adopted prior to the occurrence of any severe environmental, health, or safety hazard. Conventional treatment methods of wastewater are insufficient, complicated, and expensive. Therefore, a method that could use environmentally friendly surfactants for the simultaneous removal of both organic and inorganic contaminants from wastewater is deemed a smart approach. Surfactants containing potential donor ligands can coordinate with metal ions, and thus such compounds can be used for the removal of toxic metals and organometallic compounds from aqueous systems. Surfactants form host-guest complexes with the hydrophobic contaminants of water and soil by a mechanism involving the encapsulation of hydrophobes into the self-assembled aggregates (micelles) of surfactants. However, because undefined amounts of surfactants may be released into the aqueous systems, attention must be paid to their own environmental risks as well. Moreover, surfactant remediation methods must be carefully analyzed in the laboratory before field implementation. The use of biosurfactants is the best choice for the removal of water toxins as such surfactants are associated with the characteristics of biodegradability, versatility, recovery, and reuse. This Review is focused on the currently employed surfactant-based soil and wastewater treatment technologies owing to their critical role in the implementation of certain solutions for controlling pollution level, which is necessary to protect human health and ensure the quality standard of the aquatic environment.

Preparation and physicochemical properties of surfactant-free emulsions using electrolytic-reduction ion water containing lithium magnesium sodium silicate.

Science.gov (United States)

Okajima, Masahiro; Wada, Yuko; Hosoya, Takashi; Hino, Fumio; Kitahara, Yoshiyasu; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

2013-04-01

Surfactant-free emulsions by adding jojoba oil, squalane, olive oil, or glyceryl trioctanoate (medium chain fatty acid triglycerides, MCT) to electrolytic-reduction ion water containing lithium magnesium sodium silicate (GE-100) were prepared, and their physiochemical properties (thixotropy, zeta potential, and mean particle diameter) were evaluated. At an oil concentration of 10%, the zeta potential was ‒22.3 ‒ ‒26.8 mV, showing no marked differences among the emulsions of various types of oil, but the mean particle diameters in the olive oil emulsion (327 nm) and MCT emulsion (295 nm) were smaller than those in the other oil emulsions (452-471 nm). In addition, measurement of the hysteresis loop area of each type of emulsion revealed extremely high thixotropy of the emulsion containing MCT at a low concentration and the olive emulsion. Based on these results, since surfactants and antiseptic agents markedly damage sensitive skin tissue such as that with atopic dermatitis, surfactant- and antiseptic-free emulsions are expected to be new bases for drugs for external use.

Biodegradable surfactant stabilized nanoscale zero-valent iron for in situ treatment of vinyl chloride and 1,2-dichloroethane

International Nuclear Information System (INIS)

Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-Wei; Che, Choi-Hong; Lien, Hsing-Lung; Huang, De-Huang

2012-01-01

Highlights: ► Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. ► Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. ► Multiple functions of biodegradable surfactants are confirmed. ► Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. ► NZVI creates reducing conditions beneficial to an anaerobic bioremediation. - Abstract: Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m 2 ). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

Experimental Study on the Properties and Displacement Effects of Polymer Surfactant Solution

Directory of Open Access Journals (Sweden)

Ke-Liang Wang

2013-01-01

Full Text Available Based on the characteristics of oil reservoirs and the requirements of further enhancing oil recovery at high water cut stage of Pubei Oilfield, the displacement performance of polymer surfactant is evaluated. Reasonable injection parameters and oil displacement effects after water flooding are also researched. Compared with conventional polymer with intermediate molecular weight, polymer surfactant has the properties of higher viscosity at low concentration condition and lower interfacial tension. Laboratory experiments indicate that the displacement effect of polymer surfactant is much better than that of conventional polymer at a slug size of 0.57 PV. The oil recovery of polymer surfactant increases by more than 10% after water flooding. Considering the actual situation of low-permeability of Pubei Oilfield reservoirs, the system viscosity of 30 mPa·s is chosen. The corresponding concentration of Type III polymer surfactant is 600 mg/L and the injected slug is 0.57 PV and the oil recovery can be increased by 11.69%.

Plasma-based water treatment: development of a general mechanistic model to estimate the treatability of different types of contaminants

Science.gov (United States)

Mededovic Thagard, Selma; Stratton, Gunnar R.; Dai, Fei; Bellona, Christopher L.; Holsen, Thomas M.; Bohl, Douglas G.; Paek, Eunsu; Dickenson, Eric R. V.

2017-01-01

To determine the types of applications for which plasma-based water treatment (PWT) is best suited, the treatability of 23 environmental contaminants was assessed through treatment in a gas discharge reactor with argon bubbling, termed the enhanced-contact reactor. The contaminants were treated in a mixture to normalize reaction conditions and convective transport limitations. Treatability was compared in terms of the observed removal rate constant (k obs). To characterize the influence of interfacial processes on k obs, a model was developed that accurately predicts k obs for each compound, as well as the contributions to k obs from each of the three general degradation mechanisms thought to occur at or near the gas-liquid interface: ‘sub-surface’, ‘surface’ and ‘above-surface’. Sub-surface reactions occur just underneath the gas-liquid interface between the contaminants and dissolved plasma-generated radicals, contributing significantly to the removal of compounds that lack surfactant-like properties and so are not highly concentrated at the interface. Surface reactions occur at the interface between the contaminants and dissolved radicals, contributing significantly to the removal of surfactant-like compounds that have high interfacial concentrations. The contaminants’ interfacial concentrations were calculated using surface-activity parameters determined through surface tension measurements. Above-surface reactions are proposed to take place in the plasma interior between highly energetic plasma species and exposed portions of compounds that extend out of the interface. This mechanism largely accounts for the degradation of surfactant-like contaminants that contain highly hydrophobic perfluorocarbon groups, which are most likely to protrude from the interface. For a few compounds, the degree of exposure to the plasma interior was supported by new and previously reported molecular dynamics simulations results. By reviewing the predicted

Experimental Study of Enhancing Oil Recovery with Weak Base Alkaline/Surfactant/Polymer

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Dandan Yin

2017-01-01

Full Text Available Na2CO3 was used together with surfactant and polymer to form the Alkaline/Surfactant/Polymer (ASP flooding system. Interfacial tension (IFT and emulsification of Dagang oil and chemical solutions were studied in the paper. The experiment results show that the ASP system can form super-low interfacial tension with crude oil and emulsified phase. The stability of the emulsion is enhanced by the Na2CO3, surfactant, and the soap generated at oil/water contact. Six core flooding experiments are conducted in order to investigate the influence of Na2CO3 concentration on oil recovery. The results show the maximum oil recovery can be obtained with 0.3 wt% surfactant, 0.6 wt% Na2CO3, and 2000 mg/L polymer. In a heterogeneous reservoir, the ASP flooding could not enhance the oil recovery by reducing IFT until it reaches the critical viscosity, which indicates expanding the sweep volume is the premise for reducing IFT to enhance oil recovery. Reducing or removing the alkali from ASP system to achieve high viscosity will reduce oil recovery because of the declination of oil displacement efficiency. Weak base ASP alkali can ensure that the whole system with sufficient viscosity can start the medium and low permeability layers and enhance oil recovery even if the IFT only reaches 10−2 mN/m.

Mercury Concentration Reduction In Waste Water By Using Liquid Surfactant Membrane Technique

International Nuclear Information System (INIS)

Prayitno; Sardjono, Joko

2000-01-01

The objective of this research is ti know effectiveness of liquid surfactant membrane in diminishing mercury found in waste water. This process can be regarded as transferring process of solved mercury from the external phase functioning as a moving phase to continue to the membrane internal one. The existence of the convection rotation results in the change of the surface pressure on the whole interface parts, so the solved mercury disperses on every interface part. Because of this rotation, the solved mercury will fulfil every space with particles from dispersion phase in accordance with its volume. Therefore, the change of the surface pressure on the whole interface parts can be kept stable to adsorb mercury. The mercury adsorbed in the internal phase moves to dispersed particles through molecule diffusion process. The liquid surfactant membrane technique in which the membrane phase is realized into emulsion contains os kerosene as solvent, sorbitan monoleat (span-80) 5 % (v/v) as surfactant, threbuthyl phosphate (TBP) 10 % (v/v) as extractant, and solved mercury as the internal phase. All of those things are mixed and stirred with 8000 rpm speed for 20 minutes. After the stability of emulsion is formed, the solved mercury is extracted by applying extraction process. The effective condition required to achieve mercury ion recovery utilizing this technique is obtained through extraction and re-extraction process. This process was conducted in 30 minutes with membrane and mercury in scale 1 : 1 on 100 ppm concentration. The results of the processes was 99,6 % efficiency. This high efficiency shows that the liquid surfactant membrane technique is very effective to reduce waste water contamined by mercury

Physicochemical investigation of mixed surfactant microemulsions: water solubilization, thermodynamic properties, microstructure, and dynamics.

Science.gov (United States)

Bardhan, Soumik; Kundu, Kaushik; Saha, Swapan K; Paul, Bidyut K

2013-12-01

In this contribution, we report on a systematic investigation of phase behavior and solubilization of water in water-in-heptane or decane aggregates stabilized by mixtures of polyoxyethylene (20) cetyl ether (Brij-58) and cetyltrimethylammonium bromide (CTAB) surfactants with varying compositions in conjugation with 1-pentanol (Pn) at fixed surfactant(s)/Pn ratio and temperature. Synergism in water solubilization was evidenced by the addition of CTAB to Brij-58 stabilized system in close proximity of equimolar composition in both oils. An attempt has been made to correlate composition dependent water solubilization and volume induced conductivity studies to provide insight into the solubilization mechanism of these mixed systems. Conductivity studies reveal the ascending curve in water solubilization capacity-(Brij-58:CTAB, w/w) profile as the interdroplet interaction branch indicating percolation of conductance and the descending curve is a curvature branch due to the rigidity of the interface in these systems. The microstructure of these systems as a function of surfactant composition has been determined by dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR) measurements. FTIR study reveals increase and decrease in relative population of bound and bulk-like water, respectively, with increase in Brij-58:CTAB (w/w). DLS measurements showed that the droplet hydrodynamic diameter (Dh) decreases significantly with the increase in Brij-58:CTAB (w/w). Further, the interfacial composition and energetic parameters for the transfer of Pn from bulk oil to the interface were evaluated by the dilution method. Formation of temperature-insensitive microemulsions and temperature invariant droplet sizes are evidenced in the vicinity of the equimolar composition. The results are interpreted in terms of a proposed mechanism. Copyright © 2013 Elsevier Inc. All rights reserved.

Increased antioxidant efficacy of tocopherols by surfactant solubilization in oil-in-water emulsions.

Science.gov (United States)

Kiralan, S Sezer; Doğu-Baykut, Esra; Kittipongpittaya, Ketinun; McClements, David Julian; Decker, Eric A

2014-10-29

The physical location of antioxidants in oil-in-water emulsions can have significant influence on their free radical scavenging activity and ability to inhibit lipid oxidation. We aimed to determine the effect of the surfactant concentration on the partitioning behavior of tocopherols (α, γ, and δ) in oil-in-water emulsions. Tween 20 (0.1, 0.5, and 1%) increased the partitioning of the tocopherols into the aqueous phase via the formation of Tween 20-tocopherol comicelles. Partitioning behavior of antioxidants was dependent upon the number of methyl groups and, thus, polarity of the tocopherols. δ-Tocopherol (one methyl group) exhibited the most partitioning into the aqueous phase, while α-tocopherol (three methyl groups) had the lowest partitioning. Lipid oxidation studies showed that the antioxidant activity of δ- and α-tocopherols was enhanced by adding Tween 20 to oil-in-water emulsions. This work suggests that surfactant micelles could increase the antioxidant activity of tocopherols by changing their physical location.

Development of electrospun nanofiber composites for pointof-use water treatment

Science.gov (United States)

Peter, Katherine T.

sorption capacity of embedded carbon nanotubes, and achieves a key balance between material strength and reactivity towards organic pollutants. Additionally, via single-pot syntheses, we develop two optimized polymer-iron oxide composites for removal of heavy metal contamination by inclusion of iron oxide nanoparticles and either cationic or anionic surfactants in the electrospinning precursor solution. In hybrid materials that contain a well-retained quaternary ammonium surfactant (tetrabutylammonium bromide) and iron oxide nanoparticles, ion exchange sites and iron oxide sites are selective for chromate and arsenate removal, respectively. We demonstrated that a sulfonate surfactant, sodium dodecyl sulfate, acted as a removable porogen and an agent for surface segregation of iron oxide nanoparticles, thus enhancing composite performance for removal of lead, copper, and cadmium. Notably, nanoparticles embedded in composites exhibited comparable activity to freely dispersed nanoparticles. Collectively, the composites developed in this work represent a substantial advance towards the overlap of effective nanomaterial immobilization and utilization of nanomaterial reactivity. Outcomes of this work advance current knowledge of nanocomposite fabrication, and contribute to the responsible and effective deployment of nanomaterials in POU drinking water treatment.

Superamphiphilic nanocontainers based on the resorcinarene - Cationic surfactant system: Synergetic self-assembling behavior

Science.gov (United States)

Gaynanova, Gulnara A.; Bekmukhametova, Alina M.; Kashapov, Ruslan R.; Ziganshina, Albina Yu.; Zakharova, Lucia Ya.

2016-05-01

Self-organization in the mixed system based on water-soluble aminomethylated calix[4]arene with sulfonatoethyl groups at the lower rim and classical cationic surfactant cetyltrimethylammonium bromide has been studied by the methods of tensiometry, conductometry, spectrophotometry, dynamic and electrophoretic light scattering. The values of the critical association concentration, the size and zeta potential values, and the solubilization capacity of mixed aggregates toward the hydrophobic probe (Sudan I) were determined.

Release of surfactant cargo from interfacially-active halloysite clay nanotubes for oil spill remediation.

Science.gov (United States)

Owoseni, Olasehinde; Nyankson, Emmanuel; Zhang, Yueheng; Adams, Samantha J; He, Jibao; McPherson, Gary L; Bose, Arijit; Gupta, Ram B; John, Vijay T

2014-11-18

Naturally occurring halloysite clay nanotubes are effective in stabilizing oil-in-water emulsions and can serve as interfacially-active vehicles for delivering oil spill treating agents. Halloysite nanotubes adsorb at the oil-water interface and stabilize oil-in-water emulsions that are stable for months. Cryo-scanning electron microscopy (Cryo-SEM) imaging of the oil-in-water emulsions shows that these nanotubes assemble in a side-on orientation at the oil-water interface and form networks on the interface through end-to-end linkages. For application in the treatment of marine oil spills, halloysite nanotubes were successfully loaded with surfactants and utilized as an interfacially-active vehicle for the delivery of surfactant cargo. The adsorption of surfactant molecules at the interface serves to lower the interfacial tension while the adsorption of particles provides a steric barrier to drop coalescence. Pendant drop tensiometry was used to characterize the dynamic reduction in interfacial tension resulting from the release of dioctyl sulfosuccinate sodium salt (DOSS) from halloysite nanotubes. At appropriate surfactant compositions and loadings in halloysite nanotubes, the crude oil-saline water interfacial tension is effectively lowered to levels appropriate for the dispersion of oil. This work indicates a novel concept of integrating particle stabilization of emulsions together with the release of chemical surfactants from the particles for the development of an alternative, cheaper, and environmentally-benign technology for oil spill remediation.

Cost Effective Surfactant Formulations for Improved Oil Recovery in Carbonate Reservoirs

Energy Technology Data Exchange (ETDEWEB)

William A. Goddard; Yongchun Tang; Patrick Shuler; Mario Blanco; Yongfu Wu

2007-09-30

This report summarizes work during the 30 month time period of this project. This was planned originally for 3-years duration, but due to its financial limitations, DOE halted funding after 2 years. The California Institute of Technology continued working on this project for an additional 6 months based on a no-cost extension granted by DOE. The objective of this project is to improve the performance of aqueous phase formulations that are designed to increase oil recovery from fractured, oil-wet carbonate reservoir rock. This process works by increasing the rate and extent of aqueous phase imbibition into the matrix blocks in the reservoir and thereby displacing crude oil normally not recovered in a conventional waterflood operation. The project had three major components: (1) developing methods for the rapid screening of surfactant formulations towards identifying candidates suitable for more detailed evaluation, (2) more fundamental studies to relate the chemical structure of acid components of an oil and surfactants in aqueous solution as relates to their tendency to wet a carbonate surface by oil or water, and (3) a more applied study where aqueous solutions of different commercial surfactants are examined for their ability to recover a West Texas crude oil from a limestone core via an imbibition process. The first item, regarding rapid screening methods for suitable surfactants has been summarized as a Topical Report. One promising surfactant screening protocol is based on the ability of a surfactant solution to remove aged crude oil that coats a clear calcite crystal (Iceland Spar). Good surfactant candidate solutions remove the most oil the quickest from the surface of these chips, plus change the apparent contact angle of the remaining oil droplets on the surface that thereby indicate increased water-wetting. The other fast surfactant screening method is based on the flotation behavior of powdered calcite in water. In this test protocol, first the calcite

Mitigation of soil water repellency improves rootzone water status and yield in precision irrigated apples

Science.gov (United States)

Kostka, S.; Gadd, N.; Bell, D.

2009-04-01

Water repellent soils are documented to impact a range of hydrological properties, yet studies evaluating the consequences of soil water repellency (SWR) and its mitigation on crop yield and quality are conspicuously absent. With global concerns on drought and water availability and the projected impacts of climate change, development of novel strategies to optimize efficient rootzone delivery of water are required. Co-formulations of alkyl polyglycoside (APG) and ethylene oxide-propylene oxide (EO/PO) block copolymer surfactants have been shown to improve wetting synergistically. The objectives of this study were to determine if this surfactant technology: 1) increased soil water content and wetting front depth in mini-sprinkler irrigated, water repellent, Goulburn Valley clay loam soils and 2) assess the consequence of SWR mitigation on yield of Malus domestica Borkh. Three trials were conducted in the apple varieties 'Pink Lady' (2006/07 and 2007/08) and 'Gala' (2007/08) growing on Goulburn Valley clay loam soils in Victoria, AU. The test design was a randomized complete block with treatments replicated 5-6 times. Plot size varied by location. SWR was mitigated by applying surfactant at initial rates of 0, 5, or 10 L ha-1 in the spring, then at 0, 2.5, or 5 L ha-1 monthly for up to four months and compared to an untreated control. Treatments were applied to tree lines using a hand held small plot sprayer (118 liters of spray solution ha-1) followed by irrigation within 1-3 days of treatment applications. At each location, plots were irrigated by mini sprinklers and received the same irrigation volumes and management practices. Soil volumetric water content (VWC) was monitored at depths of 0-10 and 10-20 cm using a Theta probe (Delta-T Devices, Cambridge, UK). At harvest, fruit number and weights were measured and used for crop yield estimations. Data were analyzed using analysis of variance with mean values summarized and separated using Least Significant Test

Surfactant-free synthesis of nickel nanoparticles in near-critical water

International Nuclear Information System (INIS)

Hald, Peter; Bremholm, Martin; Iversen, Steen Brummerstedt; Iversen, Bo Brummerstedt

2008-01-01

Nickel nanoparticles have been produced by combining two well-tested methods: (i) the continuous flow supercritical reactor and (ii) the reduction of a nickel salt with hydrazine. The normal precipitation of a nickel-hydrazine complex, which would complicate pumping and mixing of the precursor, was controlled by the addition of ammonia to the precursor solution, and production of nickel nanoparticles with average sizes from 40 to 60 nm were demonstrated. The method therefore provides some size control and enables the production of nickel nanoparticles without the use of surfactants. The pure nickel nanoparticles can be easily isolated using a magnet. - Graphical abstract: A surfactant-free synthesis route to nickel nanoparticles has been successfully transferred to near-critical water conditions reducing synthesis times from hours to seconds. Nickel nanoparticles in the 40-60 nm range have been synthesised from an ammonia stabilised hydrazine complex with the average size controlled by reaction temperature

Occurrence of xenobiotics in gray water and removal in three biological treatment systems

NARCIS (Netherlands)

Hernandez Leal, L.; Vieno, N.; Temmink, B.G.; Zeeman, G.; Buisman, C.J.N.

2010-01-01

Eighteen selected xenobiotics related to personal care and household chemicals (UV-filters, fragrances, preservatives, biocides, surfactants) were measured in gray water from 32 houses and in effluents of three different biological treatment systems (aerobic, anaerobic, and combined anaerobic +

Modification of Deeply Buried Hydrophobic Interfaces by Ionic Surfactants

Energy Technology Data Exchange (ETDEWEB)

L Tamam; D Pontoni Z Sapir; S Yefet; S Sloutskin; B Ocko; H Reichert; M Deutsch

2011-12-31

Hydrophobicity, the spontaneous segregation of oil and water, can be modified by surfactants. The way this modification occurs is studied at the oil-water interface for a range of alkanes and two ionic surfactants. A liquid interfacial monolayer, consisting of a mixture of alkane molecules and surfactant tails, is found. Upon cooling, it freezes at T{sub s}, well above the alkane's bulk freezing temperature, T{sub b}. The monolayer's phase diagram, derived by surface tensiometry, is accounted for by a mixtures-based theory. The monolayer's structure is measured by high-energy X-ray reflectivity above and below T{sub s}. A solid-solid transition in the frozen monolayer, occurring approximately 3 C below T{sub s}, is discovered and tentatively suggested to be a rotator-to-crystal transition.

Poly(ethylene oxide) surfactant polymers.

Science.gov (United States)

Vacheethasanee, Katanchalee; Wang, Shuwu; Qiu, Yongxing; Marchant, Roger E

2004-01-01

We report on a series of structurally well-defined surfactant polymers that undergo surface-induced self-assembly on hydrophobic biomaterial surfaces. The surfactant polymers consist of a poly(vinyl amine) backbone with poly(ethylene oxide) and hexanal pendant groups. The poly(vinyl amine) (PVAm) was synthesized by hydrolysis of poly(N-vinyl formamide) following free radical polymerization of N-vinyl formamide. Hexanal and aldehyde-terminated poly(ethylene oxide) (PEO) were simultaneously attached to PVAm via reductive amination. Surfactant polymers with different PEO:hexanal ratios and hydrophilic/hydrophobic balances were prepared, and characterized by FT-IR, 1H-NMR and XPS spectroscopies. Surface active properties at the air/water interface were determined by surface tension measurements. Surface activity at a solid surface/water interface was demonstrated by atomic force microscopy, showing epitaxially molecular alignment for surfactant polymers adsorbed on highly oriented pyrolytic graphite. The surfactant polymers described in this report can be adapted for simple non-covalent surface modification of biomaterials and hydrophobic surfaces to provide highly hydrated interfaces.

Viscoelastic diamine surfactant for stable carbon dioxide/water foams over a wide range in salinity and temperature.

Science.gov (United States)

Elhag, Amro S; Da, Chang; Chen, Yunshen; Mukherjee, Nayan; Noguera, Jose A; Alzobaidi, Shehab; Reddy, Prathima P; AlSumaiti, Ali M; Hirasaki, George J; Biswal, Sibani L; Nguyen, Quoc P; Johnston, Keith P

2018-07-15

The viscosity and stability of CO 2 /water foams at elevated temperature can be increased significantly with highly viscoelastic aqueous lamellae. The slow thinning of these viscoelastic lamellae leads to greater foam stability upon slowing down Ostwald ripening and coalescence. In the aqueous phase, the viscoelasticity may be increased by increasing the surfactant tail length to form more entangled micelles even at high temperatures and salinity. Systematic measurements of the steady state shear viscosity of aqueous solutions of the diamine surfactant (C 16-18 N(CH 3 )C 3 N(CH 3 ) 2 ) were conducted at varying surfactant concentrations and salinity to determine the parameters for formation of entangled wormlike micelles. The apparent viscosity and stability of CO 2 /water foams were compared for systems with viscoelastic entangled micellar aqueous phases relative to those with much less viscous spherical micelles. We demonstrated for the first time stable CO 2 /water foams at temperatures up to 120 °C and CO 2 volumetric fractions up to 0.98 with a single diamine surfactant, C 16-18 N(CH 3 )C 3 N(CH 3 ) 2 . The foam stability was increased by increasing the packing parameter of the surfactant with a long tail and methyl substitution on the amine to form entangled viscoelastic wormlike micelles in the aqueous phase. The foam was more viscous and stable compared to foams with spherical micelles in the aqueous lamellae as seen with C 12-14 N(EO) 2 and C 16-18 N(EO)C 3 N(EO) 2 . Copyright © 2018. Published by Elsevier Inc.

Interfacial behaviour between oil/water systems using ionic surfactants from regional vegetable industry and animal pet

Energy Technology Data Exchange (ETDEWEB)

Santos, Francisco Klebson G.; Alves, Juan V.A.; Dantas, Tereza N. Castro; Dutra Junior, Tarcilio V.; Barros Neto, Eduardo L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

Interfacial tension (IFT) is one of the most important physical properties in the study of fluid-fluid interfaces. In this research the surfactants - saponified coconut oil, saponified castor oil, saponified soybean oil, saponified sunflower oil and basis soap - were synthesized in laboratory, using carboxylic acids from regional industry and animal fat (bovine fat). This study focuses on the search of a high-efficient, low-cost, and safe for the environment flooding system to be applied in enhanced oil recovery. The principal aim of this work is the obtaining of interfacial tensions between oil/water systems, using the developed ionic surfactants. Results showed that the studied surfactants are able to reduce the IFT between oil and brine. The surfactant that was more effective in reducing the IFT value was the one from animal fat. The composition, as well as the kind of the bond, as saturated or unsaturated, of the surfactants has influence in the IFT value. The ionic surfactants from regional industry and animal fat besides presenting low cost propitiate very low interfacial tensions between oil and brine, favoring the interactions with residual oil and thus increasing oil recovery. (author)

Micropipette Technique Study of Natural and Synthetic Lung Surfactants at the Air–Water Interface

DEFF Research Database (Denmark)

Ortiz, Elisa Parra; Kinoshita, K.; Needham, D.

2016-01-01

at microscopic air-water interfaces in real time and upon compression. Here, we characterized a series of animal-derived and synthetic lung surfactant formulations, including native surfactant obtained from porcine lungs (NS); the commercial Curosurf, Infasurf, and Survanta; and a synthetic Super Mini-B (SMB...... of myelin figures, proposing a combined mechanism between dehydration-rehydration of the lipid bilayers and induction of mechanical defects by SMB that would act as nucleation sites for the tubes. The formation of tubes was also observed in Infasurf, and in NS only after subsequent expansion and compression...

Drivers and applications of integrated clean-up technologies for surfactant-enhanced remediation of environments contaminated with polycyclic aromatic hydrocarbons (PAHs).

Science.gov (United States)

Liang, Xujun; Guo, Chuling; Liao, Changjun; Liu, Shasha; Wick, Lukas Y; Peng, Dan; Yi, Xiaoyun; Lu, Guining; Yin, Hua; Lin, Zhang; Dang, Zhi

2017-06-01

Surfactant-enhanced remediation (SER) is considered as a promising and efficient remediation approach. This review summarizes and discusses main drivers on the application of SER in removing polycyclic aromatic hydrocarbons (PAHs) from contaminated soil and water. The effect of PAH-PAH interactions on SER efficiency is, for the first time, illustrated in an SER review. Interactions between mixed PAHs could enhance, decrease, or have no impact on surfactants' solubilization power towards PAHs, thus affecting the optimal usage of surfactants for SER. Although SER can transfer PAHs from soil/non-aqueous phase liquids to the aqueous phase, the harmful impact of PAHs still exists. To decrease the level of PAHs in SER solutions, a series of SER-based integrated cleanup technologies have been developed including surfactant-enhanced bioremediation (SEBR), surfactant-enhanced phytoremediation (SEPR) and SER-advanced oxidation processes (SER-AOPs). In this review, the general considerations and corresponding applications of the integrated cleanup technologies are summarized and discussed. Compared with SER-AOPs, SEBR and SEPR need less operation cost, yet require more treatment time. To successfully achieve the field application of surfactant-based technologies, massive production of the cost-effective green surfactants (i.e. biosurfactants) and comprehensive evaluation of the drivers and the global cost of SER-based cleanup technologies need to be performed in the future. Copyright © 2017. Published by Elsevier Ltd.

Degradation of surfactants by sono-irradiation

International Nuclear Information System (INIS)

Ashokkumar, M.; Grieser, F.; Vinodgopal, K.

2000-01-01

Full text: The ultrasound induced decomposition of a commercially available polydisperse nonylphenol ethoxylate surfactant (Teric GN9) has been investigated. Nearly 90% mineralization and/or degradation into volatile products of the surfactant is achieved after sonication for 24 hours. Ultrasound has been found to be a useful tool to achieve a number of chemical processes. Linear and branched alkyl benzene sulfonates and alkyl nonylphenol ethoxylates are widely used surfactants which accumulated in the environment and contribute to a well-recognised pollution problem. We have investigated the use of ultrasound in the degradation of both types of surfactants with the aim of understanding the mechanism of degradation in order to optimise the decomposition process. In this presentation, we report on the sonochemical degradation of Teric GN9- polydisperse, a nonylphenol ethoxylate with an average of 9 ethylene oxide units. The ultrasound unit used for the degradation studies of the surfactant solutions was an Allied Signal (ELAC Nautik) RF generator and transducer with a plate diameter of 54.5 mm operated at 363 kHz in continuous wave mode at an intensity of 2 W/cm 2 . Ultrasound induced cavitation events generate primary radicals inside gas/vapour filled bubbles. Due to the extreme conditions (T ∼ 5000 K; P ∼ 100 atm) generated within the collapsing bubble, H and OH radicals are produced by the homolysis of water molecules, if water is the medium of sonication. These primary radicals attack the surfactant molecules adsorbed at the bubble/water interface. The initial rate of reaction of the surfactant was found to be dependent on the monomer concentration in solution below and above the critical micelle concentration of the surfactants. This result strongly suggests that the initial radical attack on the surfactants occurs at the cavitation bubble/solution interface, followed by oxidative decomposition and pyrolysis of volatile fragments of the surfactant within

Co-adsorption of surfactants and water at inorganic solid surfaces.

Science.gov (United States)

Cooper, Timothy G; de Leeuw, Nora H

2002-07-21

Computer simulations of the co-adsorption of water and methanoic acid at a range of surface features of calcite and fluorite minerals have shown that the relative adsorption energies for the two minerals are reversed when solvent effects are included in the calculations, a finding which is important in the search for effective surfactant reagents in flotation techniques, which are used extensively in the mining and pharmaceutical industries and in environmental remediation processes.

Surfactant replacement therapy--economic impact.

Science.gov (United States)

Pejaver, R K; al Hifzi, I; Aldussari, S

2001-06-01

Surfactant replacement is an effective treatment for neonatal respiratory distress syndrome. (RDS). As widespread use of surfactant is becoming a reality, it is important to assess the economic implications of this new form of therapy. A comparison study was carried out at the Neonatal Intensive Care Unit (NICU) of Northwest Armed Forces Hospital, Saudi Arabia. Among 75 infants who received surfactant for RDS and similar number who were managed during time period just before the surfactant was available, but by set criteria would have made them eligible for surfactant. All other management modalities except surfactant were the same for all these babies. Based on the intensity of monitoring and nursing care required by the baby, the level of care was divided as: Level IIIA, IIIB, Level II, Level I. The cost per day per bed for each level was calculated, taking into account the use of hospital immovable equipment, personal salaries of nursing, medical, ancillary staff, overheads and maintenance, depreciation and replacement costs. Medications used, procedures done, TPN, oxygen, were all added to individual patient's total expenditure. 75 infants in the Surfactant group had 62 survivors. They spent a total of 4300 days in hospital. (av 69.35) Out of which 970 d (av 15.65 per patient) were ventilated days. There were 56 survivors in the non-surfactant group of 75. They had spent a total of 5023 days in the hospital (av 89.69/patient) out of which 1490 were ventilated days (av 26.60 d). Including the cost of surfactant (two doses), cost of hospital stay for each infant taking the average figures of stay would be SR 118, 009.75 per surfactant treated baby and SR 164, 070.70 per non-surfactant treated baby. The difference of 46,061 SR is 39.03% more in non-surfactant group. One Saudi rial = 8 Rs (approx at the time study was carried out.) Medical care cost varies from place to place. However, it is definitely cost-effective where surfactant is concerned. Quality adjusted

Surfactive stabilization of multi-walled carbon nanotube dispersions with dissolved humic substances

Energy Technology Data Exchange (ETDEWEB)

Chappell, Mark A. [Environmental Laboratory, Engineering Research and Development Center, US Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180 (United States)], E-mail: mark.a.chappell@usace.army.mil; George, Aaron J.; Dontsova, Katerina M.; Porter, Beth E. [SpecPro, Inc., 4815 Bradford Drive, Suite 201, Huntsville, AL 35805 (United States); Price, Cynthia L. [Environmental Laboratory, Engineering Research and Development Center, US Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180 (United States); Zhou Pingheng; Morikawa, Eizi [J. Bennett Johnston Sr. Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States); Kennedy, Alan J.; Steevens, Jeffery A. [Environmental Laboratory, Engineering Research and Development Center, US Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180 (United States)

2009-04-15

Soil humic substances (HS) stabilize carbon nanotube (CNT) dispersions, a mechanism we hypothesized arose from the surfactive nature of HS. Experiments dispersing multi-walled CNT in solutions of dissolved Aldrich humic acid (HA) or water-extractable Catlin soil HS demonstrated enhanced stability at 150 and 300 mg L{sup -1} added Aldrich HA and Catlin HS, respectively, corresponding with decreased CNT mean particle diameter (MPD) and polydispersivity (PD) of 250 nm and 0.3 for Aldrich HA and 450 nm and 0.35 for Catlin HS. Analogous trends in MPD and PD were observed with addition of the surfactants Brij 35, Triton X-405, and SDS, corresponding to surfactant sorption maximum. NEXAFS characterization showed that Aldrich HA contained highly surfactive domains while Catlin soil possessed a mostly carbohydrate-based structure. This work demonstrates that the chemical structure of humic materials in natural waters is directly linked to their surfactive ability to disperse CNT released into the environment. - Suspensions of multi-walled carbon nanotubes are stabilized by relatively low concentrations of dissolved humic substances in solution through surfactive mechanisms.

Surfactive stabilization of multi-walled carbon nanotube dispersions with dissolved humic substances

International Nuclear Information System (INIS)

Chappell, Mark A.; George, Aaron J.; Dontsova, Katerina M.; Porter, Beth E.; Price, Cynthia L.; Zhou Pingheng; Morikawa, Eizi; Kennedy, Alan J.; Steevens, Jeffery A.

2009-01-01

Soil humic substances (HS) stabilize carbon nanotube (CNT) dispersions, a mechanism we hypothesized arose from the surfactive nature of HS. Experiments dispersing multi-walled CNT in solutions of dissolved Aldrich humic acid (HA) or water-extractable Catlin soil HS demonstrated enhanced stability at 150 and 300 mg L -1 added Aldrich HA and Catlin HS, respectively, corresponding with decreased CNT mean particle diameter (MPD) and polydispersivity (PD) of 250 nm and 0.3 for Aldrich HA and 450 nm and 0.35 for Catlin HS. Analogous trends in MPD and PD were observed with addition of the surfactants Brij 35, Triton X-405, and SDS, corresponding to surfactant sorption maximum. NEXAFS characterization showed that Aldrich HA contained highly surfactive domains while Catlin soil possessed a mostly carbohydrate-based structure. This work demonstrates that the chemical structure of humic materials in natural waters is directly linked to their surfactive ability to disperse CNT released into the environment. - Suspensions of multi-walled carbon nanotubes are stabilized by relatively low concentrations of dissolved humic substances in solution through surfactive mechanisms

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.

Degradation of Surfactants in Hydroponic Wheat Root Zones

Science.gov (United States)

Monje, Oscar; McCoy, Lashelle; Flanagan, Aisling

Hygiene water recycling in recirculating hydroponic systems can be enhanced by plant roots by providing a substrate and root exudates for bacterial growth. However, reduced plant growth can occur during batch mode additions of high concentrations of surfactant. An analog hygiene water stream containing surfactants (Steol CS330, Mirataine CB) was added to a hydroponically-grown wheat plant root zone. The plants were grown at 700 mol mol-1 CO2, a photosynthetic photon flux of 300 mol m-2 s-1, and a planting density of 380 plants m-2. Volumetric oxygen mass transfer coefficients were determined using the fermentative/dynamic outgassing method to maintain adequate oxygen mass transfer rates in the root zone. This analysis suggested an optimal flow rate of the hydroponic solution of 5 L min-1. The hydroponic system was inoculated with biofilm from a bioreactor and rates of surfactant degradation were measured daily based on reduction in chemical oxygen demand (COD). The COD decreased from 400 to 100 mg L-1 after 2 days following batch addition of the analog hygiene water to the hydroponic system. Measurements of dissolved oxygen concentration and solution temperature suggest that the root zone was provided adequate aeration to meet both oxygen demands from plant and microbial respiration during the degradation of the surfactant. Results from this study show that hydroponic systems can be used to enhance rates of hygiene water processing.

Adsorption of β-casein-surfactant mixed layers at the air-water interface evaluated by interfacial rheology.

Science.gov (United States)

Maestro, Armando; Kotsmar, Csaba; Javadi, Aliyar; Miller, Reinhard; Ortega, Francisco; Rubio, Ramón G

2012-04-26

This work presents a detailed study of the dilational viscoelastic moduli of the adsorption layers of the milk protein β-casein (BCS) and a surfactant at the liquid/air interface, over a broad frequency range. Two complementary techniques have been used: a drop profile tensiometry technique and an excited capillary wave method, ECW. Two different surfactants were studied: the nonionic dodecyldimethylphosphine oxide (C12DMPO) and the cationic dodecyltrimethylammonium bromide (DoTAB). The interfacial dilational elasticity and viscosity are very sensitive to the composition of protein-surfactant mixed adsorption layers at the air/water interface. Two different dynamic processes have been observed for the two systems studied, whose characteristic frequencies are close to 0.01 and 100 Hz. In both systems, the surface elasticity was found to show a maximum when plotted versus the surfactant concentration. However, at frequencies above 50 Hz the surface elasticity of BCS + C12DMPO is higher than the one of the aqueous BCS solution over most of the surfactant concentration range, whereas for the BCS + DoTAB it is smaller for high surfactant concentrations and higher at low concentrations. The BCS-surfactant interaction modifies the BCS random coil structure via electrostatic and/or hydrophobic interactions, leading to a competitive adsorption of the BCS-surfactant complexes with the free, unbound surfactant molecules. Increasing the surfactant concentration decreases the adsorbed proteins. However, the BCS molecules are rather strongly bound to the interface due to their large adsorption energy. The results have been fitted to the model proposed by C. Kotsmar et al. ( J. Phys. Chem. B 2009 , 113 , 103 ). Even though the model describes well the concentration dependence of the limiting elasticity, it does not properly describe its frequency dependence.

Surfactant-enhanced recovery of dissolved hydrocarbons at petroleum production facilities

International Nuclear Information System (INIS)

Freeman, J.T.; Mayes, M.; Wassmuth, F.; Taylor, K.; Rae, W.; Kuipers, F.

1997-01-01

The feasibility and cost effectiveness of surfactant-enhanced pumping to reduce source concentrations of petroleum hydrocarbons from contaminated soils was discussed. Light non-aqueous phase liquids (LNAPL) hydrocarbons are present beneath many petroleum production processing facilities in western Canada. Complete removal of LNAPLs from geologic materials is difficult and expensive. Treatment technologies include costly ex-situ methods such as excavation and in-situ methods such as physical extraction by soil venting and pumping, bioremediation, and combination methods such as bioventing, bioslurping or air sparging. Surfactant-aided pumping can reduce source hydrocarbon concentrations when used in conjunction with traditional pump and treat, or deep well injection. This study involved the selection of an appropriate surfactant from a wide variety of commercially available products. A site contaminated by hydrocarbons in Turner Valley, Alberta, was used for field scale testing. One of the major problems was quantifying the increase in the dissolved hydrocarbon concentrations in the recovered water once a surfactant was added. From the 30 surfactants screened in a series of washing and oil solubilization tests, two surfactants, Brij 97 and Tween 80, were selected for further evaluation. Increased hydrocarbon recovery was observed within 10 days of the introduction of the first surfactant. 2 refs., 7 figs

Adsorption of natural surfactants present in sea waters at surfaces of minerals: contact angle measurements

Directory of Open Access Journals (Sweden)

Katarzyna Boniewicz-Szmyt

2009-09-01

Full Text Available The wetting properties of solid mineral samples (by contact angles in original surfactant-containing sea water (Gulf of Gdańsk, Baltic were characterised under laboratory conditions on a large set (31 samples of well-classified stones of diverse hydrophobicity using the sessile drop (ADSA-P approach, captive bubble and inclined plate methods. An experimental relation between the static contact angle θeq and stone density ρ was obtained in the form θeq = Bρ + C, where B = 12.23 ± 0.92, C = - (19.17 ± 0.77, and r2 = 0.92. The histogram of θeq distribution for polished stone plates exhibited a multimodal feature indicating that the most abundant solid materials (hydrophilic in nature have contact angles θeq = 7.2, 10.7, 15.7 and 19.2º, which appear to be applicable to unspecified field stones as well. The contact angle, a pH-dependent quantity, appears to be a sensitive measure of stone grain size, e.g. granite. The captive bubble method gives reproducible results in studies of porous and highly hydrophilic surfaces such as stones and wood. The authors consider the adsorption of natural sea water surfactants on stone surfaces to be the process responsible for contact angle hysteresis. In the model, an equation was derived for determining the solid surface free energy from the liquid's surface tension γLV it also enabled the advancing θA and receding θR contact angles of this liquid to be calculated. Measurements of contact angle hysteresis Δθ (=θA - θR with surfactant-containing sea water and distilled water (reference on the same stone surfaces allowed the film pressure ΔΠ (1.22 to 8.80 mJ m-2, solid surface free energy ΔγS (-17.03 to -23.61 mJ m-2 and work done by spreading ΔWS (-1.23 to -11.52 mJ m-2 to be determined. The variability in these parameters is attributed to autophobing, an effect operative on a solid surface covered with an adsorptive layer of surfactants. The wetting behaviour of solid particles is of great

Surfactant -- Where Are We in 2003?

Directory of Open Access Journals (Sweden)

JF Lewis

2004-01-01

Full Text Available Surfactant research has progressed over the past several years to the extent that exogenous surfactant administration in patients with the acute respiratory distress syndrome (ARDS is now being evaluated. Unfortunately, clinical responses have been variable, and we now need to take a look at how surfactant is altered in this disease so that more effective treatment strategies can be developed. This review briefly discusses the biophysical and host defense properties of surfactant, the impact of mechanical ventilation (MV on the endogenous surfactant system and the most recent clinical data involving exogenous surfactant administration in patients with ARDS. Discussions regarding future directions of surfactant research both in ARDS and diseases other than acute lung injury are included.

Relating Structure to Efficiency in Surfactant-Free Polymer/Fullerene Nanoparticle-Based Organic Solar Cells.

Science.gov (United States)

Gärtner, Stefan; Clulow, Andrew J; Howard, Ian A; Gilbert, Elliot P; Burn, Paul L; Gentle, Ian R; Colsmann, Alexander

2017-12-13

Nanoparticle dispersions open up an ecofriendly route toward printable organic solar cells. They can be formed from a variety of organic semiconductors by using miniemulsions that employ surfactants to stabilize the nanoparticles in dispersion and to prevent aggregation. However, whenever surfactant-based nanoparticle dispersions have been used to fabricate solar cells, the reported performances remain moderate. In contrast, solar cells from nanoparticle dispersions formed by precipitation (without surfactants) can exhibit power conversion efficiencies close to those of state-of-the-art solar cells processed from blend solutions using chlorinated solvents. In this work, we use small-angle neutron scattering measurements and transient absorption spectroscopy to investigate why surfactant-free nanoparticles give rise to efficient organic solar cells. We show that surfactant-free nanoparticles comprise a uniform distribution of small semiconductor domains, similar to that of bulk-heterojunction films formed using traditional solvent processing. This observation differs from surfactant-based miniemulsion nanoparticles that typically exhibit core-shell structures. Hence, the surfactant-free nanoparticles already possess the optimum morphology for efficient energy conversion before they are assembled into the photoactive layer of a solar cell. This structural property underpins the superior performance of the solar cells containing surfactant-free nanoparticles and is an important design criterion for future nanoparticle inks.

Synthesis and Surface Activity of Cationic Amino Acid-Based Surfactants in Aqueous Solution.

Science.gov (United States)

Greber, Katarzyna E

2017-01-01

I studied the possibility of using amino acid-based surfactants as emulsifiers at the same time as preservatives. Fourteen lipopeptides were synthesized employing a solid phase peptide synthesis procedure. All compounds were designed to be positively charged from +1 to +4 and acylated with fatty acid chain-palmitic and miristic. The surface activity of the obtained lipopeptides was tested using a semi-automatic tensiometer to calculate parameters describing the behavior of lipopeptides in the air/water interface. Such parameters as CMC, surface tension at the CMC point ( σ CMC ), effectiveness ( π CMC ), and efficiency (pC20) were measured. Emulsifying properties of all lipopeptides were also examined. The studies reveal that the surface active properties of synthesized compounds strongly depend on the length of alkyl chains as well as on the composition of amino acid polar heads. The critical micelle concentration decreases with increasing alkyl chain length of lipopeptides with the same polar head. The effectiveness and efficiency decrease when the number of amino acids in the polar head increases. All lipopeptides established a very weak emulsification power and created unstable water/Miglyol 812 and water/paraffin oil emulsions. Results suggest that lipopeptides cannot be used as emulsifiers; nonetheless, it is possible to use them as auxiliary surfactants with disinfectant properties in combination with more potent emulsifiers.

The inhibition of methane hydrate formation by water alignment underneath surface adsorption of surfactants

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Ngoc N.; Nguyen, Anh V.; Dang, Liem X.

2017-06-01

Sodium dodecyl sulfate (SDS) has been widely shown to strongly promote the formation of methane hydrate. Here we show that SDS displays an extraordinary inhibition effect on methane hydrate formation when the surfactant is used in sub-millimolar concentration (around 0.3 mM). We have also employed Sum Frequency Generation vibrational spectroscopy (SFG) and molecular dynamics simulation (MDS) to elucidate the molecular mechanism of this inhibition. The SFG and MDS results revealed a strong alignment of water molecules underneath surface adsorption of SDS in its sub-millimolar solution. Interestingly, both the alignment of water and the inhibition effect (in 0.3 mM SDS solution) went vanishing when an oppositely-charged surfactant (tetra-n-butylammonium bromide, TBAB) was suitably added to produce a mixed solution of 0.3 mM SDS and 3.6 mM TBAB. Combining structural and kinetic results, we pointed out that the alignment of water underneath surface adsorption of dodecyl sulfate (DS-) anions gave rise to the unexpected inhibition of methane hydration formation in sub-millimolar solution of SDS. The adoption of TBAB mitigated the SDS-induced electrostatic field at the solution’s surface and, therefore, weakened the alignment of interfacial water which, in turn, erased the inhibition effect. We discussed this finding using the concept of activation energy of the interfacial formation of gas hydrate. The main finding of this work is to reveal the interplay of interfacial water in governing gas hydrate formation which sheds light on a universal molecular-scale understanding of the influence of surfactants on gas hydrate formation. This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. The calculations were carried out using computer resources provided by the Office of Basic Energy Sciences.

Molecular dynamics simulations of surfactant and nanoparticle self-assembly at liquid-liquid interfaces

Energy Technology Data Exchange (ETDEWEB)

Luo Mingxiang; Dai, Lenore L [Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409 (United States)

2007-09-19

We have performed molecular dynamics (MD) simulations to investigate self-assembly at water-trichloroethylene (TCE) interfaces with the emphasis on systems containing modified hydrocarbon nanoparticles (1.2 nm in diameter) and sodium dodecyl sulfate (SDS) surfactants. The nanoparticles and surfactants were first distributed randomly in the water phase. The MD simulations have clearly shown the progress of migration and final equilibrium of the SDS molecules at the water-TCE interfaces with the nanoparticles either at or in the vicinity of the interfaces. One unique feature is the 'attachment' of surfactant molecules to the nanoparticle clusters in the water phase followed by the 'detachment' at the water-TCE interfaces. At low concentrations of surfactants, the surfactants and nanoparticles co-equilibrate at the interfaces. However, the surfactants, at high concentrations, competitively dominate the interfaces and deplete nanoparticles away from the interfaces. The interfacial properties, such as interfacial thickness and interfacial tension, are significantly influenced by the presence of the surfactants, but not the nanoparticles. The order of the surfactants at the interfaces increases with increasing surfactant concentration, but is independent of nanoparticle concentration. Finally, the simulation has shown that surfactants can aggregate along the water-TCE interfaces, with and without the presence of nanoparticles.

Amino acid-substituted gemini surfactant-based nanoparticles as safe and versatile gene delivery agents.

Science.gov (United States)

Singh, Jagbir; Yang, Peng; Michel, Deborah; Verrall, Ronald E; Foldvari, Marianna; Badea, Ildiko

2011-05-01

Gene based therapy represents an important advance in the treatment of diseases that heretofore have had either no treatment or cure. To capitalize on the true potential of gene therapy, there is a need to develop better delivery systems that can protect these therapeutic biomolecules and deliver them safely to the target sites. Recently, we have designed and developed a series of novel amino acid-substituted gemini surfactants with the general chemical formula C(12)H(25) (CH(3))(2)N(+)-(CH(2))(3)-N(AA)-(CH(2))(3)-N(+) (CH(3))(2)-C(12)H(25) (AA= glycine, lysine, glycyl-lysine and, lysyl-lysine). These compounds were synthesized and tested in rabbit epithelial cells using a model plasmid and a helper lipid. Plasmid/gemini/lipid (P/G/L) nanoparticles formulated using these novel compounds achieved higher gene expression than the nanoparticles containing the parent unsubstituted compound. In this study, we evaluated the cytotoxicity of P/G/L nanoparticles and explored the relationship between transfection efficiency/toxicity and their physicochemical characteristics (such as size, binding properties, etc.). An overall low toxicity is observed for all complexes with no significant difference among substituted and unsubstituted compounds. An interesting result revealed by the dye exclusion assay suggests a more balanced protection of the DNA by the glycine and glycyl-lysine substituted compounds. Thus, the higher transfection efficiency is attributed to the greater biocompatibility and flexibility of the amino acid/peptide-substituted gemini surfactants and demonstrates the feasibility of using amino acid-substituted gemini surfactants as gene carriers for the treatment of diseases affecting epithelial tissue.

Exfoliation of clays in poly(dimethylsiloxane) rubber using an unexpected couple: a silicone surfactant and water.

Science.gov (United States)

Labruyère, Céline; Monteverde, Fabien; Alexandre, Michaël; Dubois, Philippe

2009-04-01

Poly(dimethylsiloxane) (PDMS)/montmorillonite (MMT) composites have been prepared using a newly synthesized omega-ammonium functionalized poly(dimethylsiloxane) compatibilizer coupled with a dispersion technique in water. The organoclay containing the new siloxane surfactant was characterized by TGA and XRD. For the first time, a nanoscopic dispersion of MMT nanoplatelets in the PDMS composite cured by hydrosilylation and a good compatibility between clay layers and matrix were obtained. The beneficial effect of both the surfactant and the water onto clay nanoplatelet dispersion was evaluated by different microscopy techniques and by measuring different properties such as the viscosity of the uncured PDMS/MMT nanodispersions, and the swelling rate and Young's modulus of the cured PDMS/MMT nanocomposites.

MICROBIAL SURFACTANTS IN ENVIRONMENTAL TECHNOLOGIES

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T. P. Pirog

2015-08-01

Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

Influence of MWCNT/surfactant dispersions on the mechanical properties of Portland cement pastes

Science.gov (United States)

Rodríguez, B.; Quintero, J. H.; Arias, Y. P.; Mendoza-Reales, O. A.; Ochoa-Botero, J. C.; Toledo-Filho, R. D.

2017-12-01

This work studies the reinforcing effect of Multi Walled Carbon Nanotubes (MWCNT) on cement pastes. A 0.35% solid concentration of MWCNT in powder was dispersed in deionized water with sodium dodecyl sulfate (cationic surfactant), cetylpyridinium chloride (anionic surfactant) and triton X-100 (amphoteric surfactant) using an ultrasonic tip processor. Three concentrations of each surfactant (1mM, 10mM and 100mM) were tested, and all samples were sonicated until an adequate dispersion degree was obtained. Cement pastes with additions of carbon nanotubes of 0.15% by mass of cement were produced in two steps; first the dispersions of MWCNT were combined with the mixing water using an ultrasonic tip processor to guarantee homogeneity, and then cement was added and mixed until a homogeneous paste was obtained. Direct tensile strength, apparent density and open porosity of the pastes were measured after 7 days of curing. It was found that the MWCNT/surfactants dispersions decrease the mechanical properties of the cement based matrix due to an increased porosity caused by the presence of surfactants.

Photo-catalytic degradation of surfactants hexadecyltrimethyl-ammonium chloride in aqueous medium - a kinetic study

International Nuclear Information System (INIS)

Soomro, S.A.; Aziz, S.; Memon, A.R.

2011-01-01

Surfactants in the environment are a prerequisite for the sustainable development of human health and ecosystems. Surfactants are important in daily life in households as well as in industrial cleansing processes. It is important to have a detailed knowledge about their lifetime in the environment, their biodegradability in wastewater treatment plants and in natural waters, and their eco toxicity. Most of the issues on environmental acceptability focus on the effects on the environment associated with the use and disposal of these surfactants. These effects are taken into account by a risk assessment. The first step in a risk assessment is to estimate the concentrations of surfactants in the environmental compartment of interest, such as wastewater treatment plant effluents, surface waters, sediments, and soils. This estimate is generated either by actual measurement or by prediction via modelling. The measured or predicted concentrations are then compared to the concentrations of surfactant known to be toxic to organisms living in these environmental compartments. There are many situations where industry is producing both heavy metals ions and organic pollutants. Successful treatment of effluents of this type to achieve legislative compliance will depend on whether the heavy metals effect the process of degradation of the organic species and whether the presence of organic molecules hinder the process of removal of heavy metals. Degradation of cationic surfactant was studied with a photolytic cell system. Compressed air was used as oxidant and the temperature was maintained at 25-30 deg. C. Effect of UV source, hydrogen peroxide (H/sub 2/O/sub 2/) and titanium (TiO/sub 2/) on Hexadecyltrimethyl-ammonium chloride (C/sub 19/H/sub 42/NCl) were recorded. HPLC and IR were used to analyse the rate of degradation of Hexadecyltrimethyl-ammonium chloride (C/sub 19/H/sub 42/NCl).

Surfactant-enhanced control of track-etch pore morphology

International Nuclear Information System (INIS)

Apel', P.Yu.; Blonskaya, I.V.; Didyk, A.Yu.; Dmitriev, S.N.; Orelovich, O.L.; Samojlova, L.I.; Vutsadakis, V.A.; Root, D.

2000-01-01

The influence of surfactants on the process of chemical development of ion tracks in polymers is studied. Based on the experimental data, a mechanism of the surfactant effect on the track-etch pore morphology is proposed. In the beginning of etching the surfactant is adsorbed on the surface and creates a layer that is quasi-solid and partially protects the surface from the etching agent. However, some etchant molecules diffuse through the barrier and react with the polymer surface. This results in the formation of a small hole at the entrance to the ion track. After the hole has attained a few annometers in diameter, the surfactant molecules penetrate into the track and cover its walls. Further diffusion of the surfactant into the growing pore is hindered. The adsorbed surfactant layer is not permeable for large molecules. In contrast, small alkali molecules and water molecules diffuse into the track and provide the etching process enlarging the pore. At this stage the transport of the surfactant into the pore channel can proceed only due to the lateral diffusion in the adsorbed layer. The volume inside the pore is free of surfactant molecules and grows at a higher rate than pore entrance. After a more prolonged etching the bottle-like (or 'cigar-like') pore channels are formed. The bottle-like shape of the pore channels depends on the etching conditions such as alkali and surfactant concentration, temperature, and type of the surfactant. The use of surfactants enables one to produce track-etch membranes with improved flow rate characteristics compared with those having cylindrical pores with the same nominal pore diameters

Lipid-based formulations for oral administration of poorly water-soluble drugs

DEFF Research Database (Denmark)

Mu, Huiling; Holm, René; Müllertz, Anette

2013-01-01

Lipid-based drug delivery systems have shown great potentials in oral delivery of poorly water-soluble drugs, primarily for lipophilic drugs, with several successfully marketed products. Pre-dissolving drugs in lipids, surfactants, or mixtures of lipids and surfactants omits the dissolving....../dissolution step, which is a potential rate limiting factor for oral absorption of poorly water-soluble drugs. Lipids not only vary in structures and physiochemical properties, but also in their digestibility and absorption pathway; therefore selection of lipid excipients and dosage form has a pronounced effect...

Indication of critical micelle concentration of nonionic surfactants with large emission change using water-soluble conjugated polymer as molecular light switch

Energy Technology Data Exchange (ETDEWEB)

Sun, Lilin, E-mail: sunlilin126@126.com [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Hao, Dan; Zhang, Ping; Qian, Zhangsheng; Shen, Weili [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Shao, Taili [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China); Department of Pharmacy, Wannan Medical College, Wuhu 241000 (China); Zhu, Changqing, E-mail: zhucq@mail.ahnu.edu.cn [Anhui Key Laboratory of Chemo-Biosensing, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000 (China)

2013-02-15

A new near-infrared water-soluble conjugated polymer, i.e. poly [2,5-di (propyloxysulfonate)-1,4-phenylene-ethynylene-9,10-anthrylene] (PPEASO3) was synthesized to investigate its interaction with surfactants. It was found that PPEASO3 has only a weak fluorescence emission at about 670 nm due to its self-aggregation in water and in aqueous solution containing a low concentration of nonionic surfactants, i.e. below their critical micelle concentration (CMC). However, a dramatic fluorescence enhancement with a large emission blue-shift (>40 nm) was found once the concentration of nonionic surfactants reached the CMC (especially for Triton X-100). An orange fluorescence could be observed even with naked-eyes under UV-lamp, which gave a direct indication for the micelle forming process and provided a simple method for the CMC determination of the nonionic surfactants. The CMC values determined by this method were in good agreement with those obtained by other techniques. The dramatic emission change observed could be ascribed to the intensive hydrophobic interaction between PPEASO3 and surfactants micelle, which greatly disrupts the aggregation of the polymer and increase the fluorescence efficiency of PPEASO3. Highlights: Black-Right-Pointing-Pointer Investigated the interaction of a new water-soluble conjugated polymer with surfactants. Black-Right-Pointing-Pointer The dramatic fluorescence enhancement and emission blue-shift were observed at the CMC. Black-Right-Pointing-Pointer The obvious emission color change could be observed with naked-eyes under UV-lamp. Black-Right-Pointing-Pointer Gave a direct indication for the micelle forming process. Black-Right-Pointing-Pointer Provided a simple method for the CMC determination of the nonionic surfactants.

Advantageous technology for treatment of laundry waters

International Nuclear Information System (INIS)

Karlin, Y.; Gorbachev, D.; Volkov, A.; Barinov, A.

2001-01-01

In this paper, based on preliminary experimental studies, an improved scheme for cleaning of laundry water is offered which allows reuse of water and components of laundry solutions and produces low amounts of secondary radioactive waste. The principal feature of the proposed process is that waste water from rinsing (60-80% of the total volume) is processed by hyperfiltration, but waste water from the laundry (20-40% of the total volume) is treated by ultrafiltration. Concentrates after reverse osmosis desalination of waste liquids (after rinsing) contain a majority of laundry waste components, since a hyperfiltration membrane efficiently retains salts and surfactant molecules. Desalinated water (permeate) after hyperfiltration is reused, further reducing the volume of liquid wastes. (author)

Transdermal delivery of flurbiprofen from surfactant-based vesicles: particle characterization and the effect of water on in vitro transport.

Science.gov (United States)

Uchino, Tomonobu; Matsumoto, Yuiko; Murata, Akiko; Oka, Toshihiko; Miyazaki, Yasunori; Kagawa, Yoshiyuki

2014-04-10

Flurbiprofen loaded rigid and elastic vesicles comprising the bilayer-forming surfactant sucrose-ester laurate were prepared by the film rehydration and extrusion method. The charge-inducing agent sodium dodecyl sulfate, and the micelle-forming surfactants, sorbitan monolaurate, polyethylene glycol monolaurate, and polysorbate 20, were used to enhance elasticity. Vesicle formulations were evaluated for size, zeta potential, (1)H and (19)F nuclear magnetic resonance (NMR) spectra, and in vitro skin permeation across Yucatan micropig (YMP) skin. Vesicle formulations were stable for 2 weeks and their mean sizes were 95-135 nm. NMR spectroscopy showed that flurbiprofen molecular mobility was restricted by interaction with vesicle components because of entrapment in vesicle bilayers. Moreover, sorbitan monolaurate-containing vesicles strongly retained flurbiprofen molecules. After non-occlusive application to YMP skin, flurbiprofen transport from all vesicle formulations was superior to that of flurbiprofen alone and remarkably decreased after water vaporization. Polarization microscopy and small-angle X-ray diffraction analysis showed that the vesicle formulation was transferred to liquid crystalline state. Suppression of vesicle transition to the liquid crystalline state was observed with applications of both large quantities and diluted samples. The presence of water in the formulations was associated with maintenance of the vesicle structure and greater flurbiprofen transport across YMP skin. Copyright © 2014 Elsevier B.V. All rights reserved.

Small angle neutron scattering study of the gemini nonionic surfactant in heavy water solutions

International Nuclear Information System (INIS)

Rajewska, A

2012-01-01

The nonionic gemini surfactant α α'-[2,4,7,9-tetramethyl-5-decyne-4,7diyl]bis[ω hydroxyl-polyoxyethylene] (S-10) was investigated in heavy water solutions only for concentrations: 2.3%, 2.5%,3%, 3.4%, 4% and 5% at temperature 25 C with small angle neutron scattering (SANS) method. All of surfactants solutions were prepared using D 2 O (99.9% deuterated, Prikladnaia Chimia, St. Petersburg, Russia) as a solvent. The nonionic gemini surfactant S-10 was obtained from Air Products and Chemicals, Inc., and used without further purification. All SANS measurements were performed on V-4 SANS spectrometer at BENSC, Berlin (Germany). Neutrons were used in wavelength range of 0.02 - 4 nm - 1. For the measurements quartz cells of were used during experiment. Up to 14 such cells were placed in a holder. Results from experiment was calculated and evaluated with PCG 2.0 program from Graz University (Austria). In the investigated solutions two axis ellipsoidal micelles was observed.

Design, characterization, and biological evaluation of curcumin-loaded surfactant-based systems for topical drug delivery

Directory of Open Access Journals (Sweden)

Fonseca-Santos B

2016-09-01

Full Text Available Bruno Fonseca-Santos, Aline Martins dos Santos, Camila Fernanda Rodero, Maria Palmira Daflon Gremião, Marlus Chorilli School of Pharmaceutical Sciences, UNESP – São Paulo State University, Araraquara, São Paulo Brazil Abstract: From previous studies, it has been found that curcumin exhibits an anti-inflammatory activity and is being used for the treatment of skin disorders; however, it is hydrophobic and has weak penetrating ability, resulting in poor drug transport through the stratum corneum. The aim of this study was to develop liquid crystalline systems for topical administration of curcumin for the treatment of inflammation. These liquid crystalline systems were developed from oleic acid, polyoxypropylene (5 polyoxyethylene (20 cetyl alcohol, and water as the surfactant, oil phase, and aqueous phase, respectively. These systems were characterized, and polarized light microscopy showed anisotropy with lamellar mesophases (Formulation 1 and hexagonal mesophases (Formulations 2 and 3, which were confirmed by the peak ratio measured using small-angle X-ray scattering. In addition, rheological tests revealed that the formulations exhibited gel-like behavior (G'>G'', as evidenced by the increased G' values that indicate structured systems. Texture profile analysis showed that hexagonal mesophases have high values of hardness, adhesiveness, and compressibility, which indicate structured systems. In vitro studies on bioadhesion revealed that the hexagonal mesophases increased the bioadhesiveness of the systems to the skin of the pig ear. An in vivo inflammation experiment showed that the curcumin-loaded hexagonal mesophase exhibited an anti-inflammatory activity as compared to the positive control (dexamethasone. The results suggest that this system has a potential to be used as a bioadhesive vehicle for the topical administration of curcumin. Therefore, it is possible to conclude that these systems can be used for the optimization of drug

Synthesis of nanosized (polymerization in miniemulsion employing in situ surfactant formation.

Science.gov (United States)

Guo, Yi; Zetterlund, Per B

2011-10-18

A novel method for synthesis of ultrafine polymeric nanoparticles of diameters less than 20 nm has been developed. The method is based on miniemulsion polymerization exploiting combination of the in situ surfactant generation approach (whereby the surfactant is formed at the oil-water interface by reaction between an organic acid and a base) and ultrasonication. Conventional radical polymerization and nitroxide-mediated radical polymerization of styrene have been conducted in miniemulsion using oleic acid/potassium hydroxide, demonstrating that particles with diameters less than 20 nm can be obtained by this approach at surfactant contents much lower than traditionally required in microemulsion polymerizations. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Use of watershed factors to predict consumer surfactant toxic units in the upper Trinity river, Texas

DEFF Research Database (Denmark)

Johnson, David; Sanderson, Hans; Atkinson, Sam

2009-01-01

Surfactants are high production volume chemicals that are used in a wide assortment of "down-the-drain" consumer products. Wastewater treatment plants (WWTPs) generally remove 85 to more than 99% of all surfactants from influents, but residual concentrations are discharged into receiving waters v...... the potential to be a reliable and inexpensive method of predicting water and habitat quality in the upper Trinity River watershed and perhaps other highly urbanized watersheds in semi-arid regions. © 2009 Elsevier B.V. All rights reserved. Udgivelsesdato: June 15...

Hydrocarbon-degrading bacteria isolation and surfactant influence ...

African Journals Online (AJOL)

Hydrocarbons are substantially insoluble in water, often remaining partitioned in the non-aqueous phase liquid (NAPL). However, there had been little or no attempts to advance the bioavailability of hydrocarbons through the use of surfactants. This study was conducted based on the need to isolate hydrocarbon degrading ...

High Charge-Carrier Mobility of 2.5 cm(2) V(-1) s(-1) from a Water-Borne Colloid of a Polymeric Semiconductor via Smart Surfactant Engineering.

Science.gov (United States)

Cho, Jangwhan; Cheon, Kwang Hee; Ahn, Hyungju; Park, Kwang Hun; Kwon, Soon-Ki; Kim, Yun-Hi; Chung, Dae Sung

2015-10-07

Semiconducting polymer nanoparticles dispersed in water are synthesized by a novel method utilizing non-ionic surfactants. By developing a smart surfactant engineering technique involving a selective post-removal process of surfactants, an unprecedentedly high mobility of 2.51 cm(2) V(-1) s(-1) from a water-borne colloid is demonstrated for the first time. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Control study of pulmonary surfactant combined with CPAP and BIPAP ventilation modes respectively in treatment of neonatal NRDS

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Yao Liu

2016-04-01

Full Text Available Objective: To analyze the differences in effect of pulmonary surfactant combined with CPAP and BIPAP ventilation modes respectively in treatment of neonatal NRDS. Methods: A total of 50 cases of children with neonatal respiratory distress syndrome (NRDS born and receiving treatment in our hospital from August 2012 to January 2015 were selected as research subjects and randomly divided into observation group and control group, each with 25 cases. Control group received pulmonary surfactant combined with CPAP ventilation mode treatment, observation group received pulmonary surfactant combined with BIPAP ventilation mode treatment, and then differences in blood gas indicators and mechanical ventilation parameters, pulmonary artery pressure, endothelin and nitric oxide levels, blood coagulation and anticoagulation indicators and protein expression levels of CD24, TNF-α, IL-6 and IL-17A of two groups after treatment were compared. Results: PaO2, PH value and oxygenation index of observation group after treatment were higher than those of control group, and PaCO2, positive end-expiratory pressure, peak inspiratory pressure and inspired oxygen concentration were lower than those of control group; pulmonary artery pressure and EF-1 level of observation group after treatment were lower than those of control group, and NO level was higher than that of control group; PC, TPS and AT-Ⅲ levels of observation group after treatment were higher than those of control group, and D-D and vWF levels were lower than those of control group; protein expression of CD24 and IL-6 of observation group after treatment were lower than those of control group, and protein expression of TNF-α and IL-17A were higher than those of control group. Conclusion: Pulmonary surfactant combined with BIPAP ventilation mode treatment of children with NRDS can effectively optimize ventilation function and realize homeostasis, and it has active clinical significance.

A simplified treatment of surfactant effects on cloud drop activation

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T. Raatikainen

2011-02-01

Full Text Available Dissolved surface active species, or surfactants, have a tendency to partition to solution surface and thereby decrease solution surface tension. Activating cloud droplets have large surface-to-volume ratios, and the amount of surfactant molecules in them is limited. Therefore, unlike with macroscopic solutions, partitioning to the surface can effectively deplete the droplet interior of surfactant molecules.

Surfactant partitioning equilibrium for activating cloud droplets has so far been solved numerically from a group of non-linear equations containing the Gibbs adsorption equation coupled with a surface tension model and an optional activity coefficient model. This can be a problem when surfactant effects are examined by using large-scale cloud models. Namely, computing time increases significantly due to the partitioning calculations done in the lowest levels of nested iterations.

Our purpose is to reduce the group of non-linear equations to simple polynomial equations with well known analytical solutions. In order to do that, we describe surface tension lowering using the Szyskowski equation, and ignore all droplet solution non-idealities. It is assumed that there is only one surfactant exhibiting bulk-surface partitioning, but the number of non-surfactant solutes is unlimited. It is shown that the simplifications cause only minor errors to predicted bulk solution concentrations and cloud droplet activation. In addition, computing time is decreased at least by an order of magnitude when using the analytical solutions.

Selenium Adsorption To Aluminum-Based Water Treatment Residuals

Science.gov (United States)

Aluminum-based water treatment residuals (WTR) can adsorb water-and soil-borne P, As(V), As(III), and perchlorate, and may be able to adsorb excess environmental selenium. WTR, clay minerals, and amorphous aluminum hydroxide were shaken for 24 hours in selenate or selenite solut...

EVALUATION OF THE USEFULNESS OF CONTINUOUS FLOW ANALYSIS FOR THE STUDY OF ANIONIC SURFACTANTS AND NONIONIC SURFACTANTS IN WATER AND SEWAGE SAMPLES

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Aleksandra Strugała-Wilczek

2014-10-01

Established methods show low limit of detection, good precision and good correctness. The described full automatic method takes effect in short-time analysis, small sample volume required for testing and waste restriction. Proposed flow injection system comply with requirements and may be successfully applied in monitoring studies as well as in the routine laboratory analysis. Rapid determination of water and waste water quality by the SFA for the content of surfactants allows an adequate response in case of exceeding the permissible concentrations, even according to the most restricted requirements.

Emulsion stability and properties of fish gelatin-based films as affected by palm oil and surfactants.

Science.gov (United States)

Nilsuwan, Krisana; Benjakul, Soottawat; Prodpran, Thummanoon

2016-05-01

Gelatin films exhibit the poor water vapour barrier properties. The use of palm oil, which is abundant and available in Thailand, can be a means to lower water vapour migration. To disperse oil in film-forming dispersion (FFD), a surfactant along with appropriate homogenization is required. The study aimed to investigate the influence of palm oil level and surfactants in the absence or presence of glycerol on characteristics of FFD and resulting gelatin films. Similar oil droplet sizes, both d32 and d43 values, of FFD containing soy lecithin were observed, regardless of palm oil level used (P > 0.05). FFD with Tween-20 had larger droplet size as the levels of oil increased (P palm oil level increased (P 0.05). FFD containing 500 or 750 g kg(-1) palm oil using soy lecithin as a surfactant in the presence of 300 g kg(-1) glycerol had the enhanced homogeneity and stability of oil droplets. The resulting gelatin film had the improved water vapour barrier properties. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Impacts of Residual Surfactant on Tetrachloroethene (PCE) Degradation Following Pilot-Scale SEAR Treatment at a Chloroethene-Impacted Site

Science.gov (United States)

Ramsburg, C. A.; Abriola, L. M.; Pennell, K. D.; Löffler, F. E.; Gamache, M.; Petrovskis, E. A.

2003-04-01

A pilot-scale surfactant-enhanced aquifer remediation (SEAR) demonstration was completed during the summer of 2000 at the Bachman Road site (Oscoda, MI USA). For this test, an aqueous solution of 60 g/L Tween 80 (polyoxyethylene (20) sorbitan monooleate) was used to recover tetrachloroethene (PCE) from a suspected source zone, located underneath a former dry-cleaning facility. Tween 80 was selected for use based upon its demonstrated capacity to solubilize PCE, “food-grade” status, and biodegradative potential. Hydraulic control was maintained throughout the test, with 95% of the injected surfactant mass recovered by a single extraction well. Source-zone monitoring conducted 15 months after SEAR treatment revealed the presence of previously undetected volatile fatty acids (acetate and formate) and PCE degradation products (trichloroethene, cis-1,2-dichloroethene, trans-1,2-dichlorethene, and vinyl chloride), in conjunction with PCE concentration reductions of approximately two orders-of-magnitude. The detection of volatile fatty acids is relevant, as they are likely fermentation products of residual Tween 80. Microbial reductive dechlorination is limited by available electron donors, and microcosm studies demonstrated that both acetate and formate support reductively dechlorinating populations present at the oligotrophic Bachman Road site aquifer. Surfactant transport simulations, using a regional flow model developed for the site, were employed to determine appropriate down-gradient monitoring locations. Drive point samples taken 15 months post-treatment in the vicinity of the simulated residual surfactant plume, contained elevated concentrations of acetate and PCE daughter products. Ongoing efforts include continued site-monitoring, and microcosm studies to corroborate a causal relationship between Tween 80 fermentation and PCE dechlorination.

Cold pearl surfactant-based blends.

Science.gov (United States)

Crombie, R L

1997-10-01

Pearlizing agents have been used for many years in cosmetic formulations to add a pearlescent effect. Cold pearl surfactant-based blends are mixtures of glycol stearates and surfactants which can be blended in the cold into a wide range of personal-care formulations to create a pearlescent lustre effect. Under controlled manufacturing conditions constant viscosities and crystalline characteristics can be obtained. The development of these blends has been driven by efforts to improve the economics of adding solid pearlizing agents directly into a hot mix formulation. This paper summarizes the history of pearlizers, describes their advantages and physical chemistry of the manufacturing process. Finally some suggestions for applications are given. Les agents nacrants sont utilises depuis de nombreuses annees dans les formulations cosmetiques pour ajouter un effet nacre. Les melanges a froid a base de tensioactif nacre sont des melanges de stearates de glycol et de tensioactifs qui peuvent etre melanges a froid dans une large gamme de formulations d'hygiene personnelle pour creer un effet de lustre nacre. On peut obtenir des viscosites et des proprietes cristallines constantes avec des conditions de fabrication maitrisees. Le developpement de ces melanges a ete porte par les efforts pour ameliorer les couts de l'ajout d'agents nacrants solides directement dans une formulation melangee de l'ajout d'agents nacrants solides directement dans une formulation melangee a chaud. Cet article resume l'histoire des agents nacrants, decrit leurs avantages et al physico-chimie du procede de fabrication. On emet a la fin cetaines suggestions d'applications.

Pulmonary clearance of {sup 99m}Tc-DTPA in experimental surfactant dysfunction treated with surfactant installation

Energy Technology Data Exchange (ETDEWEB)

Nilsson, K.; John, J.; Lachmann, B.; Robertson, B.; Wollmer, P.

1997-02-01

Background: Breakdown of the alveolo-capillary barrier is a characteristic feature of respiratory distress syndrome. Restoration of alveolo-capillary barrier function may be an important aspect of surfactant replacement therapy. We examined the effect of surfactant installation on alveolo-capillary barrier function in an experimental model of surfactant dysfunction by measuring pulmonary clearance of {sup 99m}Tc-DTPA. Methods: Nineteen rabbits were tracheotomized and mechanically ventilated. Surfactant dysfunction was induced by administration of a synthetic detergent in aerosol form. Detergent was given to 13 rabbits; seven rabbits were then treated with installation of natural surfactant, whereas six rabbits received saline. Six rabbits were used as untreated controls. An aerosol of {sup 99m}Tc-DTPA was administered to all animals and the pulmonary clearance was measured with a gamma camera. Results: {sup 99m}Tc-DTPA cleared from the lungs with a half-life of 71{+-}22 min in the control animals, 21.4{+-}7.4 min in the surfactant-treated animals and 5.8{+-}1.5 min in the saline-treated animals. The difference in half-life between groups was highly significant (P<0.001). There was no change in arterial oxygenation or compliance in controls or in animals treated with saline. In animals treated with surfactant, a small transient reduction in arterial oxygen tension and a more long-standing reduction in compliance were observed. Conclusion: Surfactant treatment thus significantly attenuated the effect of detergent treatment but did not restore alveolo-capillary transfer of {sup 99m}Tc-DTPA to normal. (AU) 26 refs.

Application experience with ADBAC/DGH cationic surfactants for zebra mussel control in a nuclear service water system

International Nuclear Information System (INIS)

Jung, W.R.; Lacy, J.R.; Post, R.

1992-01-01

In response to the introduction and rapid growth of the zebra mussel population in the Great Lakes and the issuance of NRC Generic Letter 89-13 (Service Water Problems Affecting Safety-Related Equipment). A midwest nuclear station instituted a zebra mussel monitoring and control program. The nuclear station uses Lake Michigan as a cooling water source for two 1,100 MW Westinghouse 4-loop design, pressurized water reactors (PWR). Two years of monitoring indicated a growth in zebra mussel population from 0.5 organisms/m 2 in July 1990 to 100 organisms/m 2 by November 1990. This rapid increase indicated an urgent need for viable methods of zebra mussel control to protect the plant's essential service water (ESW) and non-essential service water (NESW) systems. In April 1991, the station formulated a plan that combined increased system inlet temperature with targeted application of a proprietary product containing two cationic surfactants, ADBAC/DGH. Sidestream biomonitoring boxes were seeded with zebra mussels and observed as a measure of the efficacy of the treatment. Where recommended dosages and duration were maintained, 100% control was achieved

Molecular interactions in a surfactant-water-polyacrylamide system, according to densimetry, viscometry, conductometry, and spectroscopy data

Science.gov (United States)

Harutyunyan, R. S.

2013-08-01

Molecular interactions in a surfactant-polyacrylamide-water system are investigated. It is established that the interactions affect such physicochemical parameters of the system as viscosity, density, surface tension, conductivity, and critical micelle concentration. It is shown that in a polyacrylamide-water system, raising the polyacrylamide concentration to 0.02% causes conformational changes in its macromolecule.

The reversed-flow gas chromatography technique as a tool for the study of the evaporation retardation of SO2 and (CH3)2S from water by soluble surfactants.

Science.gov (United States)

Sevastos, D; Kotsalos, E; Koliadima, A

2017-02-01

In the present work the evaporation retardation of SO 2 and (CH 3 ) 2 S (=DMS) from water by soluble surfactants was studied by the Reversed-Flow Gas Chromatography (R.F.G.C.) technique. Using suitable mathematical analysis, rate coefficients, k c , for the transfer of SO 2 and DMS from pure or artificial sea water to the atmospheric environment were determined in the presence or the absence of surfactants. The efficiency of the three surfactants used (CTAB, TRITON X-100 and SDS) to retard the evaporation rate of SO 2 and DMS from water was estimated by the decrease of the k c values in the presence of the three surfactants, compared to those in the absence of surfactants. The more efficient surfactant for the retardation evaporation of SO 2 from both the pure and the artificial sea water was found to be the cationic CTAB surfactant, as the maximum decreases of the k c values were found to be 4.61×10 -3 cms -1 (number of films, n=1) and 3.07×10 -3 cms -1 (n=3), respectively. On the other hand, more efficient surfactant for the retardation evaporation of DMS from pure water was found to be the non-ionic TRITON X-100, in which the decrease of the k c value was estimated to be 18.20×10 -3 cms -1 (n=3) and from artificial sea water the cationic CTAB surfactant in which the decrease of the k c value was found to be 8.24×10 -3 cms -1 (n=3). Finally, the precision of the R.F.G.C. method in studying the retardation effect of various surfactants in the transfer of SO 2 and DMS from the water body to the atmosphere is estimated (mean value 96.69%), and the experimental values of k c are compared with those given in the literature. Copyright © 2016 Elsevier B.V. All rights reserved.

Adsorption of ionic surfactants at microscopic air-water interfaces using the micropipette interfacial area-expansion method

DEFF Research Database (Denmark)

Kinoshita, Koji; Parra, Elisa; Needham, David

2017-01-01

The dynamic adsorption of ionic surfactants at air-water interfaces have been less-well studied than that of the simpler non-ionics since experimental limitations on dynamic surface tension (DST) measurements create inconsistencies in their kinetic analysis. Using our newly designed "Micropipette...... interfacial area-expansion method", we have measured and evaluated both equilibrium and dynamic adsorption of a well-known anionic surfactant, sodium dodecyl sulphate (SDS), in the absence or presence of 100mM NaCl. Our focus was to determine if and to what extent the inclusion of a new correction parameter...... for the "ideal ionic activity", A±i, can renormalize both equilibrium and dynamic surface tension measurements and provide better estimates of the diffusion coefficient of ionic surfactants in aqueous media obtained from electroneutral models, namely extended Frumkin isotherm and Ward-Tordai adsorption models...

EVALUATION OF STABILITY OF EMULSION OIL / WATER FRONT OF THE USE OF DIFFERENT SURFACTANTS

Directory of Open Access Journals (Sweden)

Fernanda Cristina Wiedusch Sindelar

2013-05-01

Full Text Available The reuse of waste generated by various industrial sectors is a practice that has been increasingly used due to impairment of industries with their social responsibility (environmental protection or the requirements of the protection of the environment, since many residues do not have proper disposal. In the processing industry in the reuse of stones is no different. This study aims to evaluate the reuse of the oil used as a lubricant in the stone processing industry, along with water, surfactants and corrosion. To prepare the emulsions samples were used of diesel oil as a lubricant used in the cutting industry this type of industry, plus the following surfactants: Tween 20, Tween 80, sodium lauryl ether sulphate and Cetiol HE. After completing the pH, viscosity, density and phase separation in these emulsions, the conclusion was reached that the surfactant Sodium Lauryl Ether Sulfate provided the best formulation. Using this result, new emulsions prepared with the surfactant Sodium Lauryl Ether Sulfate and an anticorrosive, in this case, sodium molybdate. In such solutions containing sodium molybdate were analyzed power anticorrosive this substance, using the SAE 1020 steel plates. After these analyzes, it was found that the addition of an anticorrosive may reduce or inhibit oxidation, but in other cases, as in this study, can promote oxidation even greater.

Nighttime oxidation of surfactants at the air-water interface: effects of chain length, head group and saturation

Science.gov (United States)

Sebastiani, Federica; Campbell, Richard A.; Rastogi, Kunal; Pfrang, Christian

2018-03-01

Reactions of the key atmospheric nighttime oxidant NO3 with organic monolayers at the air-water interface are used as proxies for the ageing of organic-coated aqueous aerosols. The surfactant molecules chosen for this study are oleic acid (OA), palmitoleic acid (POA), methyl oleate (MO) and stearic acid (SA) to investigate the effects of chain length, head group and degree of unsaturation on the reaction kinetics and products formed. Fully and partially deuterated surfactants were studied using neutron reflectometry (NR) to determine the reaction kinetics of organic monolayers with NO3 at the air-water interface for the first time. Kinetic modelling allowed us to determine the rate coefficients for the oxidation of OA, POA and MO monolayers to be (2.8±0.7) × 10-8, (2.4±0.5) × 10-8and (3.3±0.6) × 10-8 cm2 molecule-1 s-1 for fitted initial desorption lifetimes of NO3 at the closely packed organic monolayers, τd, NO3, 1, of 8.1±4.0, 16±4.0 and 8.1±3.0 ns, respectively. The approximately doubled desorption lifetime found in the best fit for POA compared to OA and MO is consistent with a more accessible double bond associated with the shorter alkyl chain of POA facilitating initial NO3 attack at the double bond in a closely packed monolayer. The corresponding uptake coefficients for OA, POA and MO were found to be (2.1±0.5) × 10-3, (1.7±0.3) × 10-3 and (2.1±0.4) × 10-3, respectively. For the much slower NO3-initiated oxidation of the saturated surfactant SA we estimated a loss rate of approximately (5±1) × 10-12 cm2 molecule-1 s-1, which we consider to be an upper limit for the reactive loss, and estimated an uptake coefficient of ca. (5±1) × 10-7. Our investigations demonstrate that NO3 will contribute substantially to the processing of unsaturated surfactants at the air-water interface during nighttime given its reactivity is ca. 2 orders of magnitude higher than that of O3. Furthermore, the relative contributions of NO3 and O3 to the oxidative

Interaction of biocompatible natural rosin-based surfactants with human serum albumin: A biophysical study

International Nuclear Information System (INIS)

Ishtikhar, Mohd; Ali, Mohd Sajid; Atta, Ayman M.; Al-Lohedan, H.A.; Nigam, Lokesh; Subbarao, Naidu; Hasan Khan, Rizwan

2015-01-01

Biophysical insight into interaction of biocompatible rosin-based surfactants with human serum albumin (HSA) was studied at physiological conditions using various spectroscopic, calorimetric and molecular docking approaches. The binding constant (K b ), enthalpy (ΔH 0 ), entropy (ΔS 0 ) and Gibbs free energy change (ΔG 0 ) were calculated by spectroscopic and calorimetric method. We have also calculated the probability of energy transfer by FRET analysis. The circular dichroism study showed that the cationic surfactant QRMAE significantly altered the secondary structure of HSA as compared to the nonionic rosin surfactants. The thermodynamic study was performed by ITC to determine binding constant as well as change in enthalpy of HSA in presence of rosin surfactants. It clearly showed that hydrogen binding and hydrophobic interaction play an important role in the binding of HSA to rosin surfactants. We have also performed molecular docking studies to locate the binding site on HSA and to visualize the mode of interaction. The present study provides a significant insight into HSA–rosin surfactants interaction, which also improves our understanding of the possible effect of rosin surfactants on human health. - Highlights: • RMPEG 750 has the highest Kb, Kq and Ksv value as compared to other rosin surfactants. • The probability of energy transfer from HSA to rosin surfactants was maximum in the case of RMPEG 750. • Cationic surfactant QRMAE significantly altered the secondary structure of the HSA as compared to other rosin surfactants. • Molecular docking and ITC experiment studies, to locate the binding site on HSA and to investigate the mode of interaction

Comparison of grey water treatment performance by a cascading sand filter and a constructed wetland.

Science.gov (United States)

Kadewa, W W; Le Corre, K; Pidou, M; Jeffrey, P J; Jefferson, B

2010-01-01

A novel unplanted vertical flow subsurface constructed wetland technology comprising three shallow beds (0.6 m length, 0.45 m width and 0.2 m depth) arranged in a cascading series and a standard single-pass Vertical Flow Planted Constructed Wetland (VFPCW, 6 m² and 0.7 m depth) were tested for grey water treatment. Particular focus was on meeting consent for published wastewater reuse parameters and removal of anionic surfactants. Treatment performance at two hydraulic loading rates (HLR) of 0.08, and 0.17 m³ m⁻² d⁻¹ were compared. Both technologies effectively removed more than 90% turbidity and more than 96% for organics with the prototype meeting the most stringent reuse standard of < 2 NTU and <10 mg/L. However, surfactant removal in the VFPCW was higher (76-85%) than in the prototype which only achieved more than 50% removal at higher loading rate. Generally, the prototype performed consistently better than the VFPCW except for surfactant removal. However, at higher loading rates, both systems did not meet the reuse standard of <1 mg L⁻¹ for anionic surfactants. This observation confirms that shallow beds provide a more oxidised environment leading to higher BOD₅ and COD removals. Presence of plants in the VFPCW led to higher anionic surfactant removal, through increased microbial and sorption processes.

Organophilization of bentonite clays with non-ionic surfactants aiming their use in drilling fluids base oil

International Nuclear Information System (INIS)

Silva, I.A.; Costa, J.M.R.; Neves, G.A.; Ferreira, H.C.; Ferreira, H.S.

2010-01-01

The use of nonionic surfactants has been replacing the traditional ionic surfactants among others by its high potential for resistance to thermal degradation. This work aims at the development of organoclay by the addition of nonionic surfactants for use in drilling fluids for oil wells based oil. The bentonite clay was organophilized and then characterized by X-ray diffraction and swelling Foster, seeking the most appropriate choice of surfactant to liquid organic dispersing media: ester, diesel and paraffin. With the obtained dispersions were measured apparent viscosities and plastic. The results showed that incorporation of surfactants used in the clay interlayer spacing increased significantly and that the dispersions showed rheological properties within the specifications of PETROBRAS, for the use of organophilic clays in drilling fluids in a non-aqueous base. (author)

Structure-function relationships in pulmonary surfactant membranes: from biophysics to therapy.

Science.gov (United States)

Lopez-Rodriguez, Elena; Pérez-Gil, Jesús

2014-06-01

Pulmonary surfactant is an essential lipid-protein complex to maintain an operative respiratory surface at the mammalian lungs. It reduces surface tension at the alveolar air-liquid interface to stabilise the lungs against physical forces operating along the compression-expansion breathing cycles. At the same time, surfactant integrates elements establishing a primary barrier against the entry of pathogens. Lack or deficiencies of the surfactant system are associated with respiratory pathologies, which treatment often includes supplementation with exogenous materials. The present review summarises current models on the molecular mechanisms of surfactant function, with particular emphasis in its biophysical properties to stabilise the lungs and the molecular alterations connecting impaired surfactant with diseased organs. It also provides a perspective on the current surfactant-based strategies to treat respiratory pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

Synthesis and properties evaluation of sulfobetaine surfactant with double hydroxyl

Science.gov (United States)

Zhou, Ming; Luo, Gang; Zhang, Ze; Li, Sisi; Wang, Chengwen

2017-09-01

A series of sulfobetaine surfactants {N-[(3-alkoxy-2-hydroxyl)propoxy] ethyl-N,N-dimethyl-N-(2-hydroxyl)propyl sulfonate} ammonium chloride were synthesized with raw materials containing linear saturated alcohol, N,N-dimethylethanolamine, sodium 3-chloro-2-hydroxyl propane sulfonic acid and epichlorohydrin. The molecule structures of sulfobetaine surfactants were characterized by FTIR, 1HNMR and elemental analysis. Surface tension measurements can provide us information about the surface tension at the CMC (γCMC), pC20, Γmax and Amin. The pC20 values of sulfobetaine surfactants increase with the hydrophobic chain length increasing. Amin values of the surfactants decrease with increasing hydrophobic chain length from 10 to 14. The critical micelle concentration (CMC) and surface tension (γCMC) values of the sulfobetaine surfactants decrease with increasing hydrophobic chain length from 10 to 16. The lipophilicity of surfactant was enhanced with the increase of the carbon chain, however, the ability of anti-hard water was weakened. The minimum oil/water interfacial tension of four kinds of sulfobetaine surfactants is 10-2-10-3 mN/m magnitude, which indicates that the synthesized bis-hydroxy sulfobetaine surfactants have a great ability to reduce interfacial tension in the surfactant flooding system. The surface tension (γCMC) values of synthesized surfactants were lower compared with conventional anionic surfactant sodium dodecyl sulfonate.

Nonionic surfactant organoclay obtaining from Pedra Lavrada District, PB, Brazil

International Nuclear Information System (INIS)

Silva, I.A. da; Cardoso, M.A.F.; Figueiredo, J.M.R.; Silva, C.D.; Neves, G.A.; Ferreira, H. C.

2012-01-01

The oil industry has invested for many years in the use of smectite clay as a dispersing agent in the composition of drilling fluids for oil wells water based and oil based. The State of Paraiba is one of the largest producers of clays and recently discovered new deposits in the regions of Cubati and Pedra Lavrada by creating a great expectation of the expansion of mineral production in the region. The aim of this work is a smectite clays organophilization of the city of Pedra Lavrada, with the addition of nonionic surfactant. After organophilization clay was characterized by X-ray diffraction and Foster swelling in order to choose the most suitable surfactant through the organic liquid dispersant diesel. The results showed that incorporation of surfactant used in the clay interlayer spacing increased significantly, and that the dispersions showed rheological properties within the specifications of PETROBRAS, for use of organophilic clays in drilling fluids in nonionic base. (author)

Microwave Synthesis and Characterization of Waste Soybean Oil-Based Gemini Imidazolinium Surfactants with Carbonate Linkage

Science.gov (United States)

Tripathy, Divya Bajpai; Mishra, Anuradha

Gemini surfactants are presently gaining attention due to their unusual self-assembling characteristics and incomparable interfacial activity. Current research work involves the cost-effective microwave (MW) synthesis of waste soybean oil-based gemini imidazolinium surfactants (GIS) having a carbonate linkage in its spacer moiety. Structural characterizations of the materials have been done using FT-IR, 1H-NMR and 13C-NMR. Using indigenous and natural material as base and MW as energy source for synthesizing the GIS with easily degradable chemical moiety make them to be labeled as green surfactants.

Numerical approach for enhanced oil recovery with surfactant flooding

Directory of Open Access Journals (Sweden)

Sadegh Keshtkar

2016-03-01

Full Text Available The remained oil in the reservoir after conventional water-flooding processes, forms a dispersed phase in the form of oil drops which is trapped by capillary forces and is almost about 70% of the original oil in the place (OOIP. To reduce oil residual saturation in laboratory experiments and field projects, surfactant flooding is effective via decreasing the interfacial tension mobility ratio between oil and water phases. Estimation of the role of design variables, like chemical concentrations, partition coefficient and injection rate in different performance quantities, considering a heterogeneous and multiphase oil reservoir is a critical stage for optimal design. Increasing demand for oil production from water-flooded reservoirs has caused an increasing interest in surfactant-polymer (SP and alkali-surfactant-polymer (ASP. Modeling minimizes the risk of high cost of chemicals by improving our insight of process. In the present paper, a surfactant compositional flood model for a three-component (water, petroleum and surfactant, two phase (aqueous and oleic system is studied. A homogeneous, two-dimensional, isothermal reservoir with no free gas or alkali is assumed. The governing equations are in three categories: the continuity equations for the transport of each component, Darcy's equation for the transport of each phase and other auxiliary equations. The equations are solved by finite-differences using a procedure implicit in pressure and explicit in saturation. The validation of the model is achieved through comparing the modeling results with CMG simulators and Buckley–Leverett theory. The results of modeling showed good agreement with CMG results, and the comparison with Buckley–Leverett theory is explained according to different assumptions. After validation of the model, in order to investigate sensitivity analysis, the effects of system variables (partition coefficient, surface tension, oil viscosity and surface injection

Interaction of biocompatible natural rosin-based surfactants with human serum albumin: A biophysical study

Energy Technology Data Exchange (ETDEWEB)

Ishtikhar, Mohd [Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002 (India); Ali, Mohd Sajid [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Atta, Ayman M. [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Petroleum Application department, Egyptian Petroleum Research Institute, Ahmad Elzomor St., Nasr city, Cairo-11727 (Egypt); Al-Lohedan, H.A. [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Nigam, Lokesh; Subbarao, Naidu [Centre for Computational Biology and Bioinformatics, School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Hasan Khan, Rizwan, E-mail: rizwanhkhan@hotmail.com [Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002 (India)

2015-11-15

Biophysical insight into interaction of biocompatible rosin-based surfactants with human serum albumin (HSA) was studied at physiological conditions using various spectroscopic, calorimetric and molecular docking approaches. The binding constant (K{sub b}), enthalpy (ΔH{sup 0}), entropy (ΔS{sup 0}) and Gibbs free energy change (ΔG{sup 0}) were calculated by spectroscopic and calorimetric method. We have also calculated the probability of energy transfer by FRET analysis. The circular dichroism study showed that the cationic surfactant QRMAE significantly altered the secondary structure of HSA as compared to the nonionic rosin surfactants. The thermodynamic study was performed by ITC to determine binding constant as well as change in enthalpy of HSA in presence of rosin surfactants. It clearly showed that hydrogen binding and hydrophobic interaction play an important role in the binding of HSA to rosin surfactants. We have also performed molecular docking studies to locate the binding site on HSA and to visualize the mode of interaction. The present study provides a significant insight into HSA–rosin surfactants interaction, which also improves our understanding of the possible effect of rosin surfactants on human health. - Highlights: • RMPEG 750 has the highest Kb, Kq and Ksv value as compared to other rosin surfactants. • The probability of energy transfer from HSA to rosin surfactants was maximum in the case of RMPEG 750. • Cationic surfactant QRMAE significantly altered the secondary structure of the HSA as compared to other rosin surfactants. • Molecular docking and ITC experiment studies, to locate the binding site on HSA and to investigate the mode of interaction.

Nanocomposite formation between alpha-glucosyl stevia and surfactant improves the dissolution profile of poorly water-soluble drug.

Science.gov (United States)

Uchiyama, Hiromasa; Tozuka, Yuichi; Nishikawa, Masahiro; Takeuchi, Hirofumi

2012-05-30

The formation of a hybrid-nanocomposite using α-glucosyl stevia (Stevia-G) and surfactant was explored to improve the dissolution of flurbiprofen (FP). As reported previously, the dissolution amount of FP was enhanced in the presence of Stevia-G, induced by the formation of an FP and Stevia-G-associated nanostructure. When a small amount of sodium dodecyl sulfate (SDS) was present with Stevia-G, the amount of dissolved FP was extremely enhanced. This dissolution-enhancement effect was also observed with the cationic surfactant of dodecyl trimethyl ammonium bromide, but not with the non-ionic surfactant of n-octyl-β-D-maltopyranoside. To investigate the dissolution-enhancement effect of Stevia-G/SDS mixture, the pyrene I(1)/I(3) ratio was plotted versus the Stevia-G concentration. The pyrene I(1)/I(3) ratio of Stevia-G/SDS mixture had a sigmoidal curve at lower Stevia-G concentrations compared to the Stevia-G solution alone. These results indicate that the Stevia-G/SDS mixture provides a hydrophobic core around pyrene molecules at lower Stevia-G concentrations, leading to nanocomposite formation between Stevia-G and SDS. The nanocomposite of Stevia-G/SDS showed no cytotoxicity to Caco-2 cells at a mixture of 0.1% SDS and 1% Stevia-G solution, whereas 0.1% SDS solution showed high toxicity. These results suggest that the nanocomposite formation of Stevia-G/SDS may be useful way to enhance the dissolution of poorly water-soluble drugs without special treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

Gemini (dimeric) Surfactants

Indian Academy of Sciences (India)

is in turn bonded to an identical hydrocarbon tail; alternatively,. ~. Tail spacer ... formed is dependent on surfactant structure, temperature, ionic strength and pH. The models of GS are .... micelle to the air/water interface. Moreover, GS can be ...

Biodegradation of surfactant bearing wastes

International Nuclear Information System (INIS)

Chitra, S.; Chandran, S.; Sasidhar, P.; Lal, K.B.; Amalraj, R.V.

1991-01-01

In nuclear industry, during decontamination of protective wears and contaminated materials, detergents are employed to bring down the level of radioactive contamination within safe limits. However, the surfactant present in these wastes interferes in the chemical treatment process, reducing the decontamination factor. Biodegradation is an efficient and ecologically safe method for surfactant removal. A surfactant degrading culture was isolated and inoculated separately into simulated effluents containing 1% yeast extract and 5-100 ppm sodium lauryl sulphate (SLS) and 1% yeast extract and 5-100 ppm of commercial detergent respectively. The growth of the bacterial culture and the degradation characteristics of the surfactant in the above effluents were monitored under both dynamic and static conditions. (author). 6 refs., 6 figs., 1 tab

Water-contained surfactant-based vortex-assisted microextraction method combined with liquid chromatography for determination of synthetic antioxidants from edible oil.

Science.gov (United States)

Amlashi, Nadiya Ekbatani; Hadjmohammadi, Mohammad Reza; Nazari, Seyed Saman Seyed Jafar

2014-09-26

For the first time, a novel water-contained surfactant-based vortex-assisted microextraction method (WSVAME) was developed for the extraction of two synthetic antioxidants (t-butyl hydroquinone (TBHQ) and butylated hydroxyanisole (BHA)) from edible oil samples. The novel microextraction method is based on the injection of an aqueous solution of non-ionic surfactant, Brij-35, into the oil sample in a conical bottom glass tube to form a cloudy solution. Vortex mixing was applied to accelerate the dispersion process. After extraction and phase separation by centrifugation, the lower sediment phase was directly analyzed by HPLC. The effects of the four experimental parameters including volume and concentration of extraction solvent (aqueous solution of Brij-35), percentage of acetic acid added to the oil sample and vortex time on the extraction efficiency were studied with a full factorial design. The central composite design and multiple linear regression method were applied for the construction of the best polynomial model based on experimental recoveries. The proposed method showed good linearity within the range of 0.200-200 μg mL(-1), the square of correlation coefficient higher than 0.999 and appropriate limit of detection (0.026 and 0.020 μg mL(-1) for TBHQ and BHA, respectively), while the precision for inner-day was ≤ 3.0 (n=5) and it was ≤ 3.80 (n=5) for inter-day assay. Under the optimal condition (30 μL of 0.10 mol L(-1) Brij-35 solution as extraction solvent and vortex time 1 min), the method was successfully applied for determination of TBHQ and BHA in different commercial edible oil samples. The recoveries in all cases were above 95%, with relative standard deviations below 5%. This approach is considered as a simple, sensitive and environmentally friendly method because of biodegradability of the extraction phase and no use of organic solvent in the extraction procedure. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of soy-based surface active copolymers as surfactant ingredients in model shampoo formulations.

Science.gov (United States)

Popadyuk, A; Kalita, H; Chisholm, B J; Voronov, A

2014-12-01

A new non-toxic soybean oil-based polymeric surfactant (SBPS) for personal-care products was developed and extensively characterized, including an evaluation of the polymeric surfactant performance in model shampoo formulations. To experimentally assure applicability of the soy-based macromolecules in shampoos, either in combination with common anionic surfactants (in this study, sodium lauryl sulfate, SLS) or as a single surface-active ingredient, the testing of SBPS physicochemical properties, performance and visual assessment of SBPS-based model shampoos was carried out. The results obtained, including foaming and cleaning ability of model formulations, were compared to those with only SLS as a surfactant as well as to SLS-free shampoos. Overall, the results show that the presence of SBPS improves cleaning, foaming, and conditioning of model formulations. SBPS-based formulations meet major requirements of multifunctional shampoos - mild detergency, foaming, good conditioning, and aesthetic appeal, which are comparable to commercially available shampoos. In addition, examination of SBPS/SLS mixtures in model shampoos showed that the presence of the SBPS enables the concentration of SLS to be significantly reduced without sacrificing shampoo performance. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Communication: Salt-induced water orientation at a surface of non-ionic surfactant in relation to a mechanism of Hofmeister effect

Energy Technology Data Exchange (ETDEWEB)

Hishida, Mafumi; Kaneko, Yohei; Okuno, Masanari; Yamamura, Yasuhisa; Ishibashi, Taka-aki; Saito, Kazuya, E-mail: kazuya@chem.tsukuba.ac.jp [Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan)

2015-05-07

The behavior of water molecules at the surface of nonionic surfactant (monomyristolein) and effects of monovalent ions on the behavior are investigated using the heterodyne-detected vibrational sum frequency generation spectroscopy. It is found that water molecules at the surface are oriented with their hydrogen atoms pointing to the bulk, and that the degree of orientation depends on the anion strongly but weakly on the cation. With measured surface potentials in those saline solutions, it is concluded that the heterogeneous distribution of anions and cations in combination with the nonionic surfactant causes the water orientation. This heterogeneous distribution well explains the contrasting order of anions and cations with respect to the ion size in the Hofmeister series.

Communication: Salt-induced water orientation at a surface of non-ionic surfactant in relation to a mechanism of Hofmeister effect

International Nuclear Information System (INIS)

Hishida, Mafumi; Kaneko, Yohei; Okuno, Masanari; Yamamura, Yasuhisa; Ishibashi, Taka-aki; Saito, Kazuya

2015-01-01

The behavior of water molecules at the surface of nonionic surfactant (monomyristolein) and effects of monovalent ions on the behavior are investigated using the heterodyne-detected vibrational sum frequency generation spectroscopy. It is found that water molecules at the surface are oriented with their hydrogen atoms pointing to the bulk, and that the degree of orientation depends on the anion strongly but weakly on the cation. With measured surface potentials in those saline solutions, it is concluded that the heterogeneous distribution of anions and cations in combination with the nonionic surfactant causes the water orientation. This heterogeneous distribution well explains the contrasting order of anions and cations with respect to the ion size in the Hofmeister series

Degradation of anionic surfactants using the reactor based on dielectric barrier discharge

Directory of Open Access Journals (Sweden)

Aonyas Munera Mustafa

2016-01-01

Full Text Available Two anionic surfactants (sodium lauryl sulfate - SDS and sodium dodecylbenzenesulfonate - SDBS were treated with dielectric barrier discharge. Loss of surfactant activity, decrease of chemical oxygen demand and total organic carbon as well as lower toxicity of degradation products were determined. Effects of catalysts - hydrogen peroxide and iron (II, on parameters mentioned above, were determined. Catalysts affect the degradation of SDBS and in the case of SDS catalysts have no effect on degradation. Both catalysts induce the decrease of COD and TOC values. Toxicity of solutions after the plasma treatment is lower in all the systems tested. [Projekat Ministarstva nauke Republike Srbije, br. OI 172030

Surfactant Membrane Phases Containing Mixtures of Hydrocarbon and Fluorocarbon Surfactants

International Nuclear Information System (INIS)

de Campo, Liliana; Warr, G.G.

2005-01-01

Full text: We describe the structure and stability of sponge and lamellar phases comprising mixtures of hydrocarbon and fluorocarbon surfactants. Such mixtures can show limited miscibility with each other, forming for example coexisting populations of hydrocarbon rich and fluorocarbon rich micelles under some circumstances. Our system is based on the well-characterised lamellar and sponge phases of cetylpyridinium chloride, hexanol and 0.2M brine, into which the partially fluorinated surfactant N-1H,1H,2H,2H-tridecafluorooctylpyridinium chloride is incorporated. By probing the structures with SAXS (small angle x-ray scattering) and SANS (small angle neutron scattering) using contrast variation, and by characterizing the dynamic properties with dynamic light scattering, we will describe the effect of incorporating the fluorinated surfactant on the phase equilibria and properties of the surfactant membrane structures. (authors)

Ground water currents: Developments in innovative ground water treatment, March 1994

Energy Technology Data Exchange (ETDEWEB)

Eilers, R.

1994-03-01

;Contents: Hydrodynamic cavitation oxidation destroys organics; Biosparging documented in fuel remediation study; Surfactant flushing research to remove organic liquids from aquifers; and Compilation of Ground-Water Models (a book review).

Nonlinear vibrational spectroscopy of surfactants at liquid interfaces

Science.gov (United States)

Miranda, Paulo Barbeitas

Surfactants are widely used to modify physical and chemical properties of interfaces. They play an important role in many technological problems. Surfactant monolayers are also of great scientific interest because they are two-dimensional systems that may exhibit a very rich phase transition behavior and can also be considered as a model system for biological interfaces. In this Thesis, we use a second-order nonlinear optical technique (Sum-Frequency Generation - SFG) to obtain vibrational spectra of surfactant monolayers at liquid/vapor and solid/liquid interfaces. The technique has several advantages: it is intrinsically surface-specific, can be applied to buried interfaces, has submonolayer sensitivity and is remarkably sensitive to the conformational order of surfactant monolayers. The first part of the Thesis is concerned with surfactant monolayers at the air/water interface (Langmuir films). Surface crystallization of an alcohol Langmuir film and of liquid alkanes are studied and their phase transition behaviors are found to be of different nature, although driven by similar intermolecular interactions. The effect of crystalline order of Langmuir monolayers on the interfacial water structure is also investigated. It is shown that water forms a well-ordered hydrogen-bonded network underneath an alcohol monolayer, in contrast to a fatty acid monolayer which induces a more disordered structure. In the latter case, ionization of the monolayer becomes more significant with increase of the water pH value, leading to an electric-field-induced ordering of interfacial water molecules. We also show that the orientation and conformation of fairly complicated molecules in a Langmuir monolayer can be completely mapped out using a combination of SFG and second harmonic generation (SHG). For a quantitative analysis of molecular orientation at an interface, local-field corrections must be included. The second part is a study of self-assembled surfactant monolayers at the

Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Chen, Y C; Sun, M C

2001-01-01

This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range. Copyright 2001 John Wiley & Sons, Ltd.

Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

African Journals Online (AJOL)

Nonionic surfactant effects on the toluene dissolved in the water phase and biodegradation kinetic behaviors of toluene in a composite bead biofilter were investigated. The toluene dissolved in the water phase was enhanced by the addition of surfactant into aqueous solution and the enhancing effect was more pronounced ...

Biomimicry of surfactant protein C.

Science.gov (United States)

Brown, Nathan J; Johansson, Jan; Barron, Annelise E

2008-10-01

Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

Nighttime oxidation of surfactants at the air–water interface: effects of chain length, head group and saturation

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F. Sebastiani

2018-03-01

Full Text Available Reactions of the key atmospheric nighttime oxidant NO3 with organic monolayers at the air–water interface are used as proxies for the ageing of organic-coated aqueous aerosols. The surfactant molecules chosen for this study are oleic acid (OA, palmitoleic acid (POA, methyl oleate (MO and stearic acid (SA to investigate the effects of chain length, head group and degree of unsaturation on the reaction kinetics and products formed. Fully and partially deuterated surfactants were studied using neutron reflectometry (NR to determine the reaction kinetics of organic monolayers with NO3 at the air–water interface for the first time. Kinetic modelling allowed us to determine the rate coefficients for the oxidation of OA, POA and MO monolayers to be (2.8±0.7 × 10−8, (2.4±0.5 × 10−8and (3.3±0.6 × 10−8 cm2 molecule−1 s−1 for fitted initial desorption lifetimes of NO3 at the closely packed organic monolayers, τd, NO3, 1, of 8.1±4.0, 16±4.0 and 8.1±3.0 ns, respectively. The approximately doubled desorption lifetime found in the best fit for POA compared to OA and MO is consistent with a more accessible double bond associated with the shorter alkyl chain of POA facilitating initial NO3 attack at the double bond in a closely packed monolayer. The corresponding uptake coefficients for OA, POA and MO were found to be (2.1±0.5 × 10−3, (1.7±0.3 × 10−3 and (2.1±0.4 × 10−3, respectively. For the much slower NO3-initiated oxidation of the saturated surfactant SA we estimated a loss rate of approximately (5±1 × 10−12 cm2 molecule−1 s−1, which we consider to be an upper limit for the reactive loss, and estimated an uptake coefficient of ca. (5±1 × 10−7. Our investigations demonstrate that NO3 will contribute substantially to the processing of unsaturated surfactants at the air–water interface during nighttime given its reactivity is ca. 2 orders of magnitude higher

Adsorption studies of a water soluble dye, Reactive Red MF-3B, using sonication-surfactant-modified attapulgite clay

International Nuclear Information System (INIS)

Huang Jianhua; Liu Yuanfa; Jin Qingzhe; Wang Xingguo; Yang Jun

2007-01-01

The removal of water-soluble Reactive Red MF-3B from aqueous media by sonication-surfactant-modified attapulgite clay was studied in a batch system. The surfactant used was octodecyl trimethyl ammonium chloride (OTMAC). Adsorbent characterizations were investigated using X-ray diffraction, infrared spectroscopy, and surface area analysis. The effects of pH, contact time, initial solute concentration, adsorbent dose, and temperature on the adsorption of Reactive Red MF-3B onto modified clay were investigated. On the basis of kinetic studies, specific rate constants involved in the processes were calculated and second-order adsorption kinetics was observed in the case. Film diffusion was found to be the rate-limiting step. Reactive Red MF-3B adsorption was found to increase with increase temperature. The Reactive Red MF-3B equilibrium adsorption data were fitted to Freundlich and Langmuir isotherm models, the former being found to provide the better fit of the experimental data. Thermodynamic parameters were calculated. From the results it can be concluded that the surfactant-modified clay could be a good adsorbent for treating Reactive Red MF-3B-contaminated waters

Action of Monomeric/Gemini Surfactants on Free Cells and Biofilm of Asaia lannensis

Directory of Open Access Journals (Sweden)

Anna Koziróg

2017-11-01

Full Text Available We investigated the biological activity of surfactants based on quaternary ammonium compounds: gemini surfactant hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide (C6, synthesized by the reaction of N,N-dimethyl-N-dodecylamine with 1,6-dibromohexane, and its monomeric analogue dodecyltrimethylammonium bromide (DTAB. The experiments were performed with bacteria Asaia lannensis, a common spoilage in the beverage industry. The minimal inhibitory concentration (MIC values were determined using the tube standard two-fold dilution method. The growth and adhesive properties of bacterial cells were studied in different culture media, and the cell viability was evaluated using plate count method. Both of the surfactants were effective against the bacterial strain, but the MIC of gemini compound was significantly lower. Both C6 and DTAB exhibited anti-adhesive abilities. Treatment with surfactants at or below MIC value decreased the number of bacterial cells that were able to form biofilm, however, the gemini surfactant was more effective. The used surfactants were also found to be able to eradicate mature biofilms. After 4 h of treatment with C6 surfactant at concentration 10 MIC, the number of bacterial cells was reduced by 91.8%. The results of this study suggest that the antibacterial activity of the gemini compound could make it an effective microbiocide against the spoilage bacteria Asaia sp. in both planktonic and biofilm stages.

Action of Monomeric/Gemini Surfactants on Free Cells and Biofilm of Asaia lannensis.

Science.gov (United States)

Koziróg, Anna; Kręgiel, Dorota; Brycki, Bogumił

2017-11-22

We investigated the biological activity of surfactants based on quaternary ammonium compounds: gemini surfactant hexamethylene-1,6-bis-( N,N -dimethyl- N -dodecylammonium bromide) (C6), synthesized by the reaction of N,N -dimethyl- N- dodecylamine with 1,6-dibromohexane, and its monomeric analogue dodecyltrimethylammonium bromide (DTAB). The experiments were performed with bacteria Asaia lannensis , a common spoilage in the beverage industry. The minimal inhibitory concentration (MIC) values were determined using the tube standard two-fold dilution method. The growth and adhesive properties of bacterial cells were studied in different culture media, and the cell viability was evaluated using plate count method. Both of the surfactants were effective against the bacterial strain, but the MIC of gemini compound was significantly lower. Both C6 and DTAB exhibited anti-adhesive abilities. Treatment with surfactants at or below MIC value decreased the number of bacterial cells that were able to form biofilm, however, the gemini surfactant was more effective. The used surfactants were also found to be able to eradicate mature biofilms. After 4 h of treatment with C6 surfactant at concentration 10 MIC, the number of bacterial cells was reduced by 91.8%. The results of this study suggest that the antibacterial activity of the gemini compound could make it an effective microbiocide against the spoilage bacteria Asaia sp. in both planktonic and biofilm stages.

The effect of nanoparticle surfactant polarization on trapping depth of vegetable insulating oil-based nanofluids

Energy Technology Data Exchange (ETDEWEB)

Li, Jian, E-mail: lijian@cqu.edu.cn; Du, Bin; Wang, Feipeng; Yao, Wei; Yao, Shuhan

2016-02-05

Nanoparticles can generate charge carrier trapping and reduce the velocity of streamer development in insulating oils ultimately leading to an enhancement of the breakdown voltage of insulating oils. Vegetable insulating oil-based nanofluids with three sizes of monodispersed Fe{sub 3}O{sub 4} nanoparticles were prepared and their trapping depths were measured by thermally stimulated method (TSC). It is found that the nanoparticle surfactant polarization can significantly influence the trapping depth of vegetable insulating oil-based nanofluids. A nanoparticle polarization model considering surfactant polarization was proposed to calculate the trapping depth of the nanofluids at different nanoparticle sizes and surfactant thicknesses. The results show the calculated values of the model are in a fairly good agreement with the experimental values. - Highlights: • Three different sized Fe{sub 3}O{sub 4} vegetable-oil based nanofluids was successfully prepared. • The trapping depth of the Fe{sub 3}O{sub 4} nanofluids was investigated. • A new model considering surfactant polarization was proposed to calculate the trapping depth of the nanofluids.

Effect of Gemini-type surfactant on methane hydrate formation

Energy Technology Data Exchange (ETDEWEB)

Jeong, K.E.; Park, J.M.; Kim, C.U.; Chae, H.J.; Jeong, S.Y. [Korea Research Inst. of Chemical Technology, Jang-Dong, Yuseong-Gu, Daejeon (Korea, Republic of)

2008-07-01

Natural gas hydrates are formed from water and natural gas molecules at particular temperatures and pressures that become ice-like inclusion compounds. Gas hydrates offer several benefits such as energy resource potential and high storage capacity of natural gas in the form of hydrates. However, the application of natural gas hydrates has been deterred by its low formation rate and low conversion ratio of water into hydrate resulting in low actual storage capacity. This paper presented an experimental study to determine the effect of adding a novel Gemini-type surfactant on methane hydrate formation. The experimental study was described with reference to the properties of prepared diols and properties of prepared disulfonates. Gemini surfactant is the family of surfactant molecules possessing more than one hydrophobic tail and hydrophilic head group. They generally have better surface-active properties than conventional surfactants of equal chain length. The paper presented the results of the study in terms of the reactions of diols with propane sultone; storage capacity of hydrate formed with and without surfactant; and methane hydrate formation with and without disulfonate. It was concluded that the methane hydrate formation was accelerated by the addition of novel anionic Gemini-type surfactants and that hydrate formation was influenced by the surfactant concentration and alkyl chain length. For a given concentration, the surfactant with the highest chain length demonstrated the highest formation rate and storage capacity. 5 refs., 3 tabs., 4 figs.

Highly efficient separation of surfactant stabilized water-in-oil emulsion based on surface energy gradient and flame retardancy.

Science.gov (United States)

Long, Mengying; Peng, Shan; Deng, Wanshun; Miao, Xinrui; Wen, Ni; Zhou, Qiannan; Deng, Wenli

2018-06-15

Surface energy gradient would generate an imbalance force to drive tiny water droplets in dry air from the hydrophilic bumps to superhydrophobic domains, which has found on the Stenocara beetle's back. Inspired by this phenomenon, we introduced a pristine superhydrophilic filter paper on the lower surface energy superhydrophobic filter paper. ZnSn(OH) 6 particles and polydimethylsiloxane were mixed to prepare the superhydrophobic coating, and the coating was spray-coated on the poly(dialkyldimethylammonium chloride) covered filter paper to separate the span 80 stabilized water-in-isooctane emulsion. A pristine filter paper was added on the superhydrophobic filter paper to fabricate another membrane for separation. The results revealed that with a pristine filter paper, the membrane performed higher efficiency and more recyclability, and it could separate the emulsions with higher surfactant concentrations. The stabilized water droplets passed the superamphiphilic surface, and hindered by the superhydrophobic surface, generating a surface energy gradient for better separation. In addition, the superhydrophobic membrane could be protected from fire to some degree due to the introduced ZnSn(OH) 6 particles with excellent flame retardancy. This easy and efficient approach via simply bringing in pristine superhydrophilic membrane has great potential applications for water-in-oil emulsion separation or oil purification. Copyright © 2018 Elsevier Inc. All rights reserved.

Polyethersulfone-based ultrafiltration hollow fibre membrane for drinking water treatment systems

Science.gov (United States)

Chew, Chun Ming; Ng, K. M. David; Ooi, H. H. Richard

2017-12-01

Conventional media/sand filtration has been the mainstream water treatment process for most municipal water treatment plants in Malaysia. Filtrate qualities of conventional media/sand filtration are very much dependent on the coagulation-flocculation process prior to filtration and might be as high as 5 NTU. However, the demands for better quality of drinking water through public piped-water supply systems are growing. Polymeric ultrafiltration (UF) hollow fibre membrane made from modified polyethersulfone (PES) material is highly hydrophilic with high tensile strength and produces excellent quality filtrate of below 0.3 NTU in turbidity. This advanced membrane filtration material is also chemical resistance which allows a typical lifespan of 5 years. Comparisons between the conventional media/sand filtration and PES-based UF systems are carried out in this paper. UF has been considered as the emerging technology in municipal drinking water treatment plants due to its consistency in producing high quality filtrates even without the coagulation-flocculation process. The decreasing cost of PES-based membrane due to mass production and competitive pricing by manufacturers has made the UF technology affordable for industrial-scale water treatment plants.

The selective partitioning of the oligomers of polyethoxylated surfactant mixtures between interface and oil and water bulk phases.

Science.gov (United States)

Graciaa, Alain; Andérez, José; Bracho, Carlos; Lachaise, Jean; Salager, Jean-Louis; Tolosa, Laura; Ysambertt, Fredy

2006-11-16

Because their affinities for the oil and water phases vary considerably with the number of ethylene oxide units in their hydrophilic group, the ethoxylated nonionic species occurring in commercial products tend to behave in a non-collective way, with the low ethoxylation oligomers partitioning mostly in the oil phase. This results in a surfactant mixture at the interface which is more hydrophilic than the one which was introduced in the system in the first place. The pseudophase model is used to study the partitioning in Winsor III type systems, and to estimate the deviation of the interfacial mixture composition from the overall one. New results indicate that the selective partitioning into the oil phase increases when the oil phase becomes aromatic, when the total surfactant concentration decreases and when the water-to-oil ratio decreases.

Effectiveness of a Barge-Based Ballast Water Treatment System for Multi-Terminal Ports

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Lovro Maglić

2015-10-01

Full Text Available The paper presents outcomes of the discrete event simulation of the ballast water management in a multi-terminal port. The simulation includes ship’s manoeuvring, cargo and ballast operations and a barge-based ballast water treatment system operating within all terminal areas. The barge-based ballast water treatment system is used by ships unable to use their own equipment, not equipped with an appropriate ballast treatment system or non-compliant with the Ballast Water Management (BWM Convention 2004 for whatever reason. The main goal is to estimate the productivity and cost effectiveness of such systems as an option to support ships not able to comply with the BWM Convention, once it enters into force. The model was built and tested in Arena simulation software. Process parameters are based on real traffic data for the port of Rijeka. The results indicate that barge-based ballast treatment facility will be heavily underutilized, and that such systems are cost-effective only in ports where large volumes of ballast water need to be delivered to shore treatment systems.

Surfactant control of air-sea gas exchange from North Sea coastal waters and the Atlantic Meridional Transect

Science.gov (United States)

Pereira, R.

2016-02-01

Suppression of gas transfer velocity (kw) by surfactants are well established, both in laboratory wind flumes and purposeful oceanic releases. However, the effects on kw of time and space varying concentrations of natural surfactant are inadequately studied. We have developed an automated gas exchange tank for simultaneous high precision measurement of kw in unmodified seawater samples. Here we present data from two studies along a coastal North Sea transect during 2012-2013 and the Atlantic Meridional Transect (AMT) 24 from September to November 2014. Measurements of surfactant activity (SA), CDOM absorbance and chlorophyll-a have enabled us to characterize the effects of variable amounts of natural surfactant on kw. North Sea coastal waters range in k660 (kw normalized to the value for CO2 in freshwater at 20oC) was 6.8-24.5 cm hr-1 (n=20), with the ranges of SA, total CDOM absorbance (200-450 nm) and chlorophyll-a measured in the surface microlayer (SML) of our seawater samples were 0.08-0.38 mg l-1 T-X-100, 0.13-4.7 and 0.09-1.54 µg l-1, respectively. The AMT k660 ranged from 7.0-23.9 cm hr-1 (n=22), with SA measured in the SML and subsurface water (SSW) of our seawater samples ranging from 0.15-1.08 mg l-1 T-X-100 and 0.07-0.43 mg l-1 T-X-100, respectively. Importantly, we found 12-45% (North Sea) and 1-43% (AMT) k660 suppression relative to Milli-Q water that relate to seasonal and spatial differences in SA. The North Sea demonstrated notable seasonal influences on k660 suppression that were related to CDOM absorbance and chlorophyll-a. The degree of k660 suppression was highest in summer consistent with k660 control by natural surfactant. The degree of k660 suppression decreased with distance offshore in the North Sea and displayed a strong relationship with SA (r2 = 0.51-0.64, p = 0.02, n = 20). The AMT demonstrated notable differences in k660 suppression between hemispheres and across the Longhurst Provinces but the overall relationship between k660

The effect of surfactants on path instability of a rising bubble

Science.gov (United States)

Tagawa, Yoshiyuki; Takagi, Shu; Matsumoto, Yoichiro

2013-11-01

We experimentally investigate the surfactant effect on path instability of an air bubble rising in quiescent water. An addition of surfactant varies the gas-water boundary condition from zero shear stress to non-zero shear stress. We report three main findings: firstly, while the drag force acting on the bubble increases with the surfactant concentration as expected, the lift force shows a non-monotonic behavior; secondly, the transient trajectory starting from helical to zigzag is observed, which has never been reported in the case of purified water; lastly, a bubble with the intermediate slip conditions between free-slip and no-slip show a helical motion for a broad range of the Reynolds number. Aforementioned results are rationalized by considering the adsorption-desorption kinetics of the surfactants on gas-water interface and the wake dynamics. Y.T. thanks for financial support from Grant-in-Aid for JSPS Fellows (20-10701). We also thank for Grant-in-Aid for Scientific Research (B) (21360079).

Effect of surfactant species and electrophoretic medium composition on the electrophoretic behavior of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis.

Science.gov (United States)

Fukai, Nao; Kitagawa, Shinya; Ohtani, Hajime

2017-07-01

We have recently demonstrated the separation of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis (NACZE) using a cationic surfactant of cetyltrimethylammonium chloride (CTAC). In this study, eight ionic surfactants were investigated for the separation of four synthetic polymers (polystyrene, polymethylmethacrylates, polybutadiene, and polycarbonate); only three surfactants (CTAC, dimethyldioctadecylammonium bromide, and sodium dodecylsulfate) caused their separation. The order of the interaction between the polymers and the surfactants depended on both the surfactant species and the composition of the electrophoretic medium. Their investigation revealed that the separation is majorly affected by the hydrophobic interactions between the polymers and the ionic surfactants. In addition, the electrophoretic behavior of polycarbonate suggested that electrostatic interaction also affects the selectivity of the polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of protein based surfactants from leather waste fleshings and their reutilization in leather as a water resisting agent

International Nuclear Information System (INIS)

Nawaz, H.; Nadeem, U.; Solangi, B.; Hany, O.E.

2012-01-01

Summary: Tanneries generate a huge amount of highly polluting solid and liquid wastes during leather processing at different stages such as fleshings, shavings, tanning, finishing etc. approximately, 250 kg of finished leather product is obtained from 1 ton of raw salted hide while other protein goes into wastes. leather fleshings are about 50-60% of the total solid waste generated in leather processing. three different surfactants have been prepared from soft wax, long chain fatty acid chlorides and leather waste protein isolated from alkaline hydrolysis of fleshings. products are milky in color and have been applied in goat leathers as a replacement of fat liquor and water resisting agent .the resulted crust leathers have been characterized for various physical parameters such as tensile strength, thickness, softness, tear strength, bursting load, water absorption etc, as per their standard test methods. leathers have also been evaluated for grain smoothness, fullness and feeling. leathers have shown satisfactory results as per international requirement specially for water resisting. thus a leather waste protein is converted into a useful product and reutilized in leather making. (author)

Maintained inspiratory activity during proportional assist ventilation in surfactant-depleted cats early after surfactant instillation: phrenic nerve and pulmonary stretch receptor activity

Directory of Open Access Journals (Sweden)

Schaller Peter

2006-03-01

Full Text Available Abstract Background Inspiratory activity is a prerequisite for successful application of patient triggered ventilation such as proportional assist ventilation (PAV. It has recently been reported that surfactant instillation increases the activity of slowly adapting pulmonary stretch receptors (PSRs followed by a shorter inspiratory time (Sindelar et al, J Appl Physiol, 2005 [Epub ahead of print]. Changes in lung mechanics, as observed in preterm infants with respiratory distress syndrome and after surfactant treatment, might therefore influence the inspiratory activity when applying PAV early after surfactant treatment. Objective To investigate the regulation of breathing and ventilatory response in surfactant-depleted young cats during PAV and during continuous positive airway pressure (CPAP early after surfactant instillation in relation to phrenic nerve activity (PNA and the activity of PSRs. Methods Seven anesthetized, endotracheally intubated young cats were exposed to periods of CPAP and PAV with the same end-expiratory pressure (0.2–0.5 kPa before and after lung lavage and after surfactant instillation. PAV was set to compensate for 75% of the lung elastic recoil. Results Tidal volume and respiratory rate were higher with lower PaCO2 and higher PaO2 during PAV than during CPAP both before and after surfactant instillation (p Conclusion PSR activity and the control of breathing are maintained during PAV in surfactant-depleted cats early after surfactant instillation, with a higher ventilatory response and a lower breathing effort than during CPAP.

Guanidinium ionic liquid-based surfactants as low cytotoxic extractants: Analytical performance in an in-situ dispersive liquid-liquid microextraction method for determining personal care products.

Science.gov (United States)

Pacheco-Fernández, Idaira; Pino, Verónica; Ayala, Juan H; Afonso, Ana M

2017-05-01

The IL-based surfactant octylguanidinium chloride (C 8 Gu-Cl) was designed and synthetized with the purpose of obtaining a less harmful surfactant: containing guanidinium as core cation and a relatively short alkyl chain. Its interfacial and aggregation behavior was evaluated through conductivity and fluorescence measurements, presenting a critical micelle concentration value of 42.5 and 44.6mmolL -1 , respectively. Cytotoxicity studies were carried out with C 8 Gu-Cl and other IL-based and conventional surfactants, specifically the analogue 1-octyl-3-methylimidazolium chloride (C 8 MIm-Cl), and other imidazolium- (C 16 MIm-Br) and pyridinium- (C 16 Py-Cl) based surfactants, together with the conventional cationic CTAB and the conventional anionic SDS. From these studies, C 8 Gu-Cl was the only one to achieve the classification of low cytotoxicity. An in situ dispersive liquid-liquid microextraction (DLLME) method based on transforming the water-soluble C 8 Gu-Cl IL-based surfactant into a water-insoluble IL microdroplet via a simple metathesis reaction was then selected as the extraction/preconcentration method for a group of 6 personal care products (PCPs) present in cosmetic samples. The method was carried out in combination with high-performance liquid chromatography (HPLC) and diode array detection (DAD). The method was properly optimized, requiring the use of only 30μL of C 8 Gu-Cl for 10mL of aqueous sample with a NaCl content of 8% (w/v) to adjust the ionic strength and pH value of 5. The metathesis reaction required the addition of the anion exchange reagent (bis[(trifluoromethyl)sulfonyl]imide - 1:1 molar ratio), followed by vortex and centrifugation, and dilution of the final microdroplet up to 60μL with acetonitrile before the injection in the HPLC-DAD system. The optimum in situ DLLME-HPLC-DAD method takes ∼10min for the extraction step and ∼22min for the chromatographic separation, with analytical features of low detection limits: down to 0.4�

Splash Dynamics of Falling Surfactant-Laden Droplets

Science.gov (United States)

Sulaiman, Nur; Buitrago, Lewis; Pereyra, Eduardo

2017-11-01

Splashing dynamics is a common issue in oil and gas separation technology. In this study, droplet impact of various surfactant concentrations onto solid and liquid surfaces is studied experimentally using a high-speed imaging analysis. Although this area has been widely studied in the past, there is still not a good understanding of the role of surfactant over droplet impact and characterization of resulting splash dynamics. The experiments are conducted using tap water laden with anionic surfactant. The effects of system parameters on a single droplet impingement such as surfactant concentration (no surfactant, below, at and above critical micelle concentration), parent drop diameter (2-5mm), impact velocity and type of impact surface (thin and deep pool) are investigated. Image analysis technique is shown to be an effective technique for identification of coalescence to splashing transition. In addition, daughter droplets size distributions are analyzed qualitatively in the events of splashing. As expected, it is observed that the formation of secondary droplets is affected by the surfactant concentration. A summary of findings will be discussed.

Recovering hydrocarbons with surfactants from lignin

Energy Technology Data Exchange (ETDEWEB)

Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.

1988-11-29

This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

Nasal CPAP and surfactant for treatment of respiratory distress syndrome and prevention of bronchopulmonary dysplasia

DEFF Research Database (Denmark)

Verder, Henrik; Bohlin, Kajsa; Kamper, Jens

2009-01-01

The Scandinavian approach is an effective combined treatment for respiratory distress syndrome (RDS) and prevention of bronchopulmonary dysplasia (BPD). It is composed of many individual parts. Of significant importance is the early treatment with nasal continuous positive airway pressure (n......CPAP) and surfactant treatment. The approach may be supplemented with caffeine citrate and non-invasive positive pressure ventilation for apnoea. The low incidence of BPD seen as a consequence of the treatment strategy is mainly due to a reduced need for mechanical ventilation (MV). Conclusion: Early...

Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

Science.gov (United States)

Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

2016-02-01

The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of surfactants for the remediation of contaminated soils: A review

International Nuclear Information System (INIS)

Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

2015-01-01

Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation

Use of surfactants for the remediation of contaminated soils: A review

Energy Technology Data Exchange (ETDEWEB)

Mao, Xuhui, E-mail: clab@whu.edu.cn [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Jiang, Rui; Xiao, Wei [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Yu, Jiaguo, E-mail: jiaguoyu@yahoo.com [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2015-03-21

Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation.

Separation process for lanthanides based on solvation properties of non ionic surfactants

International Nuclear Information System (INIS)

Draye, M.; Favre-Reguillon, A.; Foos, J.; Cote, G.

2004-01-01

In the present study, cloud-point extraction is used with a lipophilic chelating agent (8-hydroxyquinoline) to extract and separate lanthanum (III) and gadolinium (III) from an aqueous solution. The methodology used is based on the formation of lanthanide (III) organic complexes that are soluble in a micellar phase of non-ionic surfactant. The lanthanide (III) complexes are then extracted into the surfactant-rich phase at a temperature above the cloud-point temperature. The cloud-point temperature, the structure of the lipophilic part of the nonionic surfactant and the chelating agent - metal molar ratio are identified as factors determining the extraction efficiency and selectivity. With Triton X-114, high selectivity and decontamination factor for Gd(III) is observed indicating that micelle mediated extraction involving cloud-point extraction is promising for the specific separation of actinide ions from nuclear waste solution. (authors)

Coupling the Alkaline-Surfactant-Polymer Technology and The Gelation Technology to Maximize Oil Production

Energy Technology Data Exchange (ETDEWEB)

Malcolm Pitts; Jie Qi; Dan Wilson; Phil Dowling; David Stewart; Bill Jones

2005-12-01

Performance and produced polymer evaluation of four alkaline-surfactant-polymer projects concluded that only one of the projects could have benefited from combining the alkaline-surfactant-polymer and gelation technologies. Cambridge, the 1993 Daqing, Mellott Ranch, and the Wardlaw alkaline-surfacant-polymer floods were studied. An initial gel treatment followed by an alkaline-surfactant-polymer flood in the Wardlaw field would have been a benefit due to reduction of fracture flow. Numerical simulation demonstrated that reducing the permeability of a high permeability zone of a reservoir with gel improved both waterflood and alkaline-surfactant-polymer flood oil recovery. A Minnelusa reservoir with both A and B sand production was simulated. A and B sands are separated by a shale layer. A sand and B sand waterflood oil recovery was improved by 196,000 bbls or 3.3% OOIP when a gel was placed in the B sand. Alkaline-surfactant-polymer flood oil recovery improvement over a waterflood was 392,000 bbls or 6.5% OOIP. Placing a gel into the B sand prior to an alkaline-surfactant-polymer flood resulted in 989,000 bbl or 16.4% OOIP more oil than only water injection. A sand and B sand alkaline-surfactant-polymer flood oil recovery was improved by 596,000 bbls or 9.9% OOIP when a gel was placed in the B sand.

Antimicrobial and biophysical properties of surfactant supplemented with an antimicrobial peptide for treatment of bacterial pneumonia.

Science.gov (United States)

Banaschewski, Brandon J H; Veldhuizen, Edwin J A; Keating, Eleonora; Haagsman, Henk P; Zuo, Yi Y; Yamashita, Cory M; Veldhuizen, Ruud A W

2015-01-01

Antibiotic-resistant bacterial infections represent an emerging health concern in clinical settings, and a lack of novel developments in the pharmaceutical pipeline is creating a "perfect storm" for multidrug-resistant bacterial infections. Antimicrobial peptides (AMPs) have been suggested as future therapeutics for these drug-resistant bacteria, since they have potent broad-spectrum activity, with little development of resistance. Due to the unique structure of the lung, bacterial pneumonia has the additional problem of delivering antimicrobials to the site of infection. One potential solution is coadministration of AMPs with exogenous surfactant, allowing for distribution of the peptides to distal airways and opening of collapsed lung regions. The objective of this study was to test various surfactant-AMP mixtures with regard to maintaining pulmonary surfactant biophysical properties and bactericidal functions. We compared the properties of four AMPs (CATH-1, CATH-2, CRAMP, and LL-37) suspended in bovine lipid-extract surfactant (BLES) by assessing surfactant-AMP mixture biophysical and antimicrobial functions. Antimicrobial activity was tested against methillicin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. All AMP/surfactant mixtures exhibited an increase of spreading compared to a BLES control. BLES+CATH-2 mixtures had no significantly different minimum surface tension versus the BLES control. Compared to the other cathelicidins, CATH-2 retained the most bactericidal activity in the presence of BLES. The BLES+CATH-2 mixture appears to be an optimal surfactant-AMP mixture based on in vitro assays. Future directions involve investigating the potential of this mixture in animal models of bacterial pneumonia. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effects of Surfactant on Geotechnical Characteristics of Silty Soil

International Nuclear Information System (INIS)

Rahman, Z.A.; Sahibin, A.R.; Lihan, T.; Idris, W.M.R.; Sakina, M.

2013-01-01

Surfactants are often used as a cleaning agent for restoration of oil-contaminated soil. However the effect of surfactant on the geotechnical properties of soil is not clearly understood. In this study, the effects of surfactant on silty soil were investigated for consistency index, compaction, permeability and shear strength. Sodium dodecyl sulfate (SDS) was used in this study to prepare the surfactant-treated soil. Our results showed that the soil with added surfactant exhibited a decrease in liquid and plastic limit values. Maximum dry densities increased and optimum moisture contents decreased as contents of added surfactant were increased. The presence of surfactant assists the soil to achieve maximum density at lower water content. The addition of surfactant decreased the permeability of soil from 6.29 x 10 -4 to 1.15 x 10 -4 ms -1 . The shear strength of soil with added surfactant was examined using the undrained unconsolidated triaxial tests. The results showed that the undrained shear strength, Cu was significantly affected, decreased from 319 kPa to 50 kPa for soil with 20 % of added surfactant. The results of this study showed that the presence of surfactant in soil can modify the mechanical behaviour of the soil. (author)

Single well surfactant test to evaluate surfactant floods using multi tracer method

Science.gov (United States)

Sheely, Clyde Q.

1979-01-01

Data useful for evaluating the effectiveness of or designing an enhanced recovery process said process involving mobilizing and moving hydrocarbons through a hydrocarbon bearing subterranean formation from an injection well to a production well by injecting a mobilizing fluid into the injection well, comprising (a) determining hydrocarbon saturation in a volume in the formation near a well bore penetrating formation, (b) injecting sufficient mobilizing fluid to mobilize and move hydrocarbons from a volume in the formation near the well bore, and (c) determining the hydrocarbon saturation in a volume including at least a part of the volume of (b) by an improved single well surfactant method comprising injecting 2 or more slugs of water containing the primary tracer separated by water slugs containing no primary tracer. Alternatively, the plurality of ester tracers can be injected in a single slug said tracers penetrating varying distances into the formation wherein the esters have different partition coefficients and essentially equal reaction times. The single well tracer method employed is disclosed in U.S. Pat. No. 3,623,842. This method designated the single well surfactant test (SWST) is useful for evaluating the effect of surfactant floods, polymer floods, carbon dioxide floods, micellar floods, caustic floods and the like in subterranean formations in much less time and at much reduced cost compared to conventional multiwell pilot tests.

Evaluation of the interaction of surfactants with stratum corneum model membrane from Bothrops jararaca by DSC.

Science.gov (United States)

Baby, André Rolim; Lacerda, Aurea Cristina Lemos; Velasco, Maria Valéria Robles; Lopes, Patrícia Santos; Kawano, Yoshio; Kaneko, Telma Mary

2006-07-06

The interaction of surfactants sodium dodecyl sulfate (SDS), cetyl trimethyl ammonium chloride (CTAC) and lauryl alcohol ethoxylated (12 mol ethylene oxide) (LAE-12OE) was evaluated on the stratum corneum (SC) of shed snake skins from Bothrops jararaca, used as model membrane, and thermal characterized by differential scanning calorimetry (DSC). Surfactant solutions were employed above of the critical micellar concentration (CMC) with treatment time of 8h. The SDS interaction with the SC model membrane has increased the characteristic transition temperature of 130 degrees C in approximately 10 degrees C for the water loss and keratin denaturation, indicating an augmentation of the water content. Samples treated with CTAC have a decrease of the water loss temperature, while, for the LAE-12OE treated samples, changes on the transition temperature have not been observed.

Ecotoxicological assessment of the pharmaceutical fluoxetine hydrochloride and the surfactant dodecyl sodium sulfate after their submission to ionizing radiation treatment

International Nuclear Information System (INIS)

Santos, Dymes Rafael Alves dos

2011-01-01

The use of pharmaceuticals and personal care products and the consequent and continuous input of this substances in the environment generates an increasing need to investigate the presence, behavior and the effects on aquatic biota, as well as new ways to treat effluents containing such substances. Fluoxetine hydrochloride is an active ingredient used in the treatment of depressive disorders and anxiety. As the surfactant sodium dodecyl sulfate is present in many cleaning and personal care products. The present study aimed on assessing the acute toxicity of fluoxetine hydrochloride, sodium dodecyl sulfate and the mixture of both to the aquatic organisms Hyalella azteca, Daphnia similis and Vibrio ficheri. Reducing the toxicity of fluoxetine and the mixture after treatment with ionizing radiation from industrial electron beam accelerator has also been the focus of this study. For Daphnia similis the average values of CE50-4 8h found for the non-irradiated drug, surfactant and mixture were 14.4 %, 9.62 % and 13.8 %, respectively. After irradiation of the substances, the dose 5 kGy proved itself to be the most effective dose for the treatment of the drug and the mixture as it was obtained the mean values for CE50 48h 84.60 % and > 90 %, respectively. For Hyalella azteca the acute toxicity tests were performed for water column with duration of 96 hours, the mean values for CE50 96h found for the drug, the surfactant and the mixture non-irradiated were 5.63 %, 19.29 %, 6.27 %, respectively. For the drug fluoxetine and the mixture irradiated with 5 kGy, it was obtained 69.57 % and 77.7 %, respectively. For Vibrio ficheri the acute toxicity tests for the untreated drug and the drug irradiated with 5 kGy it was obtained CE50 15min of 6.9 % and 32.88 % respectively. These results presented a reduction of the acute toxicity of the test-substances after irradiation. (author)

Efficiency of Combined Use of a Surfactant and the «Lung Opening» Maneuver in the Treatment of Acute Respiratory Distress Syndrome

Directory of Open Access Journals (Sweden)

A. V. Vlasenko

2007-01-01

Full Text Available The paper discusses whether the «lung opening» maneuver in combination with the endobronchial administration of a pulmonary surfactant can be used in the treatment of patients with acute respiratory distress syndrome (ARDS of various genesis. The authors outline data of their studies of the separate use of both methods and present the results of successful treatment in a patient with severe concomitant injury and posttraumatic ARDS in the combined use of the «lung opening» maneuver and Surfactant-BL. With intensive care, the combined use of these methods is a more effective way of improving gas exchange as compared with their use alone. Key words: acute respiratory distress syndrome, surfactant-BL, «lung opening» maneuver, combined use of both methods.

Identifying the Imprint of Surfactant Stabilisation in Whitecap Foam Evolution

Science.gov (United States)

Callaghan, A. H.; Deane, G. B.; Stokes, D.

2016-02-01

Surfactants are ubiquitous in the world's oceans and can affect climatically-relevant processes such as air-sea gas exchange, sea spray aerosol (SSA) flux, and air-sea momentum transfer. Surfactants are amphiphilic and help form the physically and chemically distinct ocean surface microlayer (SML), however, the spatial distribution, concentration and composition of the SML is not well understood, especially under conditions of vigorous wave breaking. Like the SML, breaking waves also influence physical exchange processes at the air-sea interface, and oceanic whitecap foam coverage is commonly used to quantify bubble-mediated exchange processes. However, surfactants can increase the lifetime of foam over clean water conditions, potentially complicating the use of whitecap coverage to parameterise air-sea gas exchange and SSA production flux. A better understanding of how surfactants affect the evolution of whitecap foam is needed to improve whitecap parameterisations of bubble-mediated processes, and may also provide a remote sensing approach to map the spatial distribution of surfactants at the water surface. Here we present results from a laboratory study that looked at whitecap foam evolution in "clean" and "surfactant-added" seawater regimes. We find that the whitecap foam area growth timescale is largely insensitive to the presence of surfactants, but that surfactant stabilization of whitecap foam becomes important during the whitecap foam area decay phase. The timescale at which this occurs appears to be consistent for breaking waves of different scale and intensity. A simple method is then used to isolate the surfactant signal and derive an equivalent "clean" seawater foam decay time for the whitecaps in the "surfactant-added" regime. The method is applied to oceanic whitecaps and results compared to the laboratory whitecaps from the "clean" and "surfactant-added" regimes.

Numerical investigation of complex flooding schemes for surfactant polymer based enhanced oil recovery

Science.gov (United States)

Dutta, Sourav; Daripa, Prabir

2015-11-01

Surfactant-polymer flooding is a widely used method of chemical enhanced oil recovery (EOR) in which an array of complex fluids containing suitable and varying amounts of surfactant or polymer or both mixed with water is injected into the reservoir. This is an example of multiphase, multicomponent and multiphysics porous media flow which is characterized by the spontaneous formation of complex viscous fingering patterns and is modeled by a system of strongly coupled nonlinear partial differential equations with appropriate initial and boundary conditions. Here we propose and discuss a modern, hybrid method based on a combination of a discontinuous, multiscale finite element formulation and the method of characteristics to accurately solve the system. Several types of flooding schemes and rheological properties of the injected fluids are used to numerically study the effectiveness of various injection policies in minimizing the viscous fingering and maximizing oil recovery. Numerical simulations are also performed to investigate the effect of various other physical and model parameters such as heterogeneity, relative permeability and residual saturation on the quantities of interest like cumulative oil recovery, sweep efficiency, fingering intensity to name a few. Supported by the grant NPRP 08-777-1-141 from the Qatar National Research Fund (a member of The Qatar Foundation).

Effect of surfactant hydrophobicity on the interfacial properties of polyallylamine hydrochloride/sodium alkylsulphate at water/hexane interface

Czech Academy of Sciences Publication Activity Database

Sharipova, A.; Aidarova, S.; Černoch, Peter; Miller, R.

2013-01-01

Roč. 438, 5 December (2013), s. 141-147 ISSN 0927-7757. [EUFOAM Conference /9./. Lisbon, 08.07.2012-11.07.2012] Institutional support: RVO:61389013 Keywords : mixed adsorption layers * polymer-surfactant mixtures * water/oil interface Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.354, year: 2013

Extraction and Characterization of Surfactants from Atmospheric Aerosols.

Science.gov (United States)

Nozière, Barbara; Gérard, Violaine; Baduel, Christine; Ferronato, Corinne

2017-04-21

Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in the Earth's atmosphere, a central process in meteorology, hydrology, and for the climate system. But because specific extraction and characterization of these compounds have been lacking for decades, very little is known on their identity, properties, mode of action and origins, thus preventing the full understanding of cloud formation and its potential links with the Earth's ecosystems. In this paper we present recently developed methods for 1) the targeted extraction of all the surfactants from atmospheric aerosol samples and for the determination of 2) their absolute concentrations in the aerosol phase and 3) their static surface tension curves in water, including their Critical Micelle Concentration (CMC). These methods have been validated with 9 references surfactants, including anionic, cationic and non-ionic ones. Examples of results are presented for surfactants found in fine aerosol particles (diameter <1 μm) collected at a coastal site in Croatia and suggestions for future improvements and other characterizations than those presented are discussed.

Kinetics of marine surfactant adsorption at an air water interface. Baltic Sea studies

Directory of Open Access Journals (Sweden)

Stanis³aw J. Pogorzelski

2001-12-01

Full Text Available The paper contains the results of studies of natural surface film adsorption kinetics carried out in inland waters and in shallow offshore regions of the Baltic Sea during 2000-01 under calm sea conditions. The novel approach presented here for the adsorption dynamics is based on the mixed kinetic-diffusion model and analyses of the surface pressure-time plots at short (t ->0 and long( t -> ∞ adsorption time intervals. Values of the effective relative diffusion coefficient Deff / D (= 0.008-0.607 and energy barrier for adsorption Ea / RT (= 0.49-7.10 agree well with the data reported for model non-ionic surfactant solutions of pre-cmc concentrations. Wind speed is one of the factors affecting the adsorption barrier via the increased surface pressure of the natural film exposed to wind shear stress (~ U102, and enters the relation Ea / RT = 1.70 U101/3.

IMPROVEMENT OF SOLUBILITY OF BADLY WATER SOLUBLE DRUG (IBUPROFEN) BY USING SURFACTANTS AND CARRIERS

OpenAIRE

Md. Zakaria Faruki*, Rishikesh, Elizabeth Razzaque, Mohiuddin Ahmed Bhuiyan

2013-01-01

ABSTRACT: Although there was a great interest in solid dispersion systems during the past four decades to increase dissolution rate and bioavailability of badly water-soluble drugs, their profitable use has been very limited, primarily because of manufacturing difficulties and stability problems. In this study solid solutions of drugs were generally produced by fusion method. The drug along with the excipients (surfactants and carriers) was heated first and then hardened by cooling to room te...

The use of Nile Red to monitor the aggregation behavior in ternary surfactant-water-organic solvent systems

NARCIS (Netherlands)

Stuart, MCA; van de Pas, JC; Engberts, JBFN; Pas, John C. van de

Ternary systems of surfactants, water and organic solvents were studied by monitoring the steady-state fluorescence of the versatile solvatochromic probe Nile Red. We found not only that Nile Red can be used throughout the whole isotropic regions in the phase diagram, but also that subtle changes in

Use of surfactants in cleaning paraffin from oil wells

Energy Technology Data Exchange (ETDEWEB)

Liebold, G; Rehberg, W

1969-05-01

The use of surfactants is described especially oxethylated alkylphenols, in the cleaning of oil wells from paraffin. Aqueous 1 or 10% solutions of the surfactant were injected into the well through the annulus, partially in combination with demulsifiers (for example Separol-brands of BASF). Injection was accomplished continuously or in intervals; in the beginning of 50 ppm surfactant, afterward 15 to 30 ppm as related to the wet crude was necessary. Efficiency of the treatment could be proved by the decrease of pressure in the pipes, the loosening of paraffin shells, and considerably prolonged operation periods in wells which otherwise would have come to a standstill. In quite a number of wells, treatment with hot oil and electric heating could be completely replaced by injection of surfactants. (11 refs.)

Biocompatible Amphiphilic Hydrogel-Solid Dimer Particles as Colloidal Surfactants.

Science.gov (United States)

Chen, Dong; Amstad, Esther; Zhao, Chun-Xia; Cai, Liheng; Fan, Jing; Chen, Qiushui; Hai, Mingtan; Koehler, Stephan; Zhang, Huidan; Liang, Fuxin; Yang, Zhenzhong; Weitz, David A

2017-12-26

Emulsions of two immiscible liquids can slowly coalesce over time when stabilized by surfactant molecules. Pickering emulsions stabilized by colloidal particles can be much more stable. Here, we fabricate biocompatible amphiphilic dimer particles using a hydrogel, a strongly hydrophilic material, and achieve large contrast in the wetting properties of the two bulbs, resulting in enhanced stabilization of emulsions. We generate monodisperse single emulsions of alginate and shellac solution in oil using a flow-focusing microfluidics device. Shellac precipitates from water and forms a solid bulb at the periphery of the droplet when the emulsion is exposed to acid. Molecular interactions result in amphiphilic dimer particles that consist of two joined bulbs: one hydrogel bulb of alginate in water and the other hydrophobic bulb of shellac. Alginate in the hydrogel compartment can be cross-linked using calcium cations to obtain stable particles. Analogous to surfactant molecules at the interface, the resultant amphiphilic particles stand at the water/oil interface with the hydrogel bulb submerged in water and the hydrophobic bulb in oil and are thus able to stabilize both water-in-oil and oil-in-water emulsions, making these amphiphilic hydrogel-solid particles ideal colloidal surfactants for various applications.

Survival, mobility, and membrane-bound enzyme activities of freshwater planarian, Dugesia japonica, exposed to synthetic and natural surfactants.

Science.gov (United States)

Li, Mei-Hui

2012-04-01

Surfactants are a major class of emerging pollutants widely used in large quantities in everyday life and commonly found in surface waters worldwide. Freshwater planarian was selected to examine the effects of different surfactants by measuring mortality, mobility, and membrane-bound enzyme activities. Among the 10 surfactants tested, the acute toxicities of betaine and polyethylene glycol (PEG-200) to planarians were relatively low, with a median lethal concentration (LC50) greater than 10,000 mg/L. The toxicity to planarians of the other eight surfactants based on 48-h LC50 could be arranged in the descending order of cetylpyridinum chloride (CPC) > 4-tert-octylphenol (4-tert-OP) > ammonium lauryl sulfate > benzalkonium chloride > saponin > sodium lauroylsarcosinate > dioctyl sulfosuccinate > dodecyl trimethyl ammonium bromide (DTAB). Both CPC and 4-tert-OP were very toxic to planarians, with 48-h LC50 values <1 mg/L. The median effective concentrations (EC50s) of planarian mobility were in the 0.1 to 50 mg/L range and were in the same range as the 24-h LC50 of planarians exposed to different surfactants, except for DTAB. In addition, significant inhibition of cholinesterase activity activities was found in planarians exposed to 4-tert-OP at 2.5 and 5 mg/L and to saponin at 10 mg/L after 2-h treatments. This result suggests that planarian mobility responses can be used as an alternative indicator for acute toxicity of surfactants after a very short exposure period. Copyright © 2012 SETAC.

An Experimental Study of Surfactant Alternating CO2 Injection for Enhanced Oil Recovery of Carbonated Reservoir

Directory of Open Access Journals (Sweden)

Asghar Gandomkar

2016-10-01

Full Text Available Core flooding experiments were conducted with the objective of evaluating near miscible surfactant alternating CO2 injection and the effect of surfactant concentrations on gas-oil and water displacements in porous media. The core samples were provided from a low permeability mixed wet oil reservoir at 156 °F and 1900 psia. In addition, very few studies of surfactant adsorption on carbonate minerals have been conducted. Hence, the surfactant adsorption on carbonate rock was determined by core flooding and crushed tests. It was found that for the crushed rock, the required equilibrium time is approximately five hours, while it is more than four days for the flow-through tests. Hysteresis effects demonstrated that the irreducible water saturations were 5 to 10% higher than the initial connate water saturation after drainage cycles during 5000 ppm surfactant solution. Furthermore, near-miscible surfactant alternating CO2 injection process led to a 4-17% increase in the recovery factor in comparison to water alternating gas process.

Surfactant media for constant-current coulometry. Application for the determination of antioxidants in pharmaceuticals

Energy Technology Data Exchange (ETDEWEB)

Ziyatdinova, Guzel, E-mail: Ziyatdinovag@mail.ru [Analytical Chemistry Department, A.M. Butlerov Institute of Chemistry, Kazan (Volga Region) Federal University, Kremlyevskaya, 18, Kazan 420008 (Russian Federation); Ziganshina, Endzhe; Budnikov, Herman [Analytical Chemistry Department, A.M. Butlerov Institute of Chemistry, Kazan (Volga Region) Federal University, Kremlyevskaya, 18, Kazan 420008 (Russian Federation)

2012-09-26

Highlights: Black-Right-Pointing-Pointer Applicability of surfactants in constant-current coulometry is shown for the first time. Black-Right-Pointing-Pointer Reactions of antioxidants with electrogenerated titrants in surfactant media are investigated. Black-Right-Pointing-Pointer Water insoluble antioxidants can be determined in water media with addition of surfactants. Black-Right-Pointing-Pointer Coulometric determination of antioxidants in pharmaceutical dosage forms using surfactants media is developed. - Abstract: Effect of surfactant presence on electrochemical generation of titrants has been evaluated and discussed for the first time. Cationic (1-dodecylpyridinium and cetylpyridinium bromide), anionic (sodium dodecyl sulfate) and nonionic (Triton X100 and Brij{sup Registered-Sign} 35) surfactants as well as nonionic high molecular weight polymer (PEG 4000) do not react with the electrogenerated bromine, iodine and hexacyanoferrate(III) ions. The electrogenerated chlorine chemically interact with Triton X100 and Brij{sup Registered-Sign} 35. The allowable range of surfactants concentrations providing 100% current yield has been found. Chain-breaking low molecular weight antioxidants (ascorbic acid, rutin, {alpha}-tocopherol and retinol) were determined by reaction with the electrogenerated titrants in surfactant media. Nonionic and cationic surfactants can be used for the determination of antioxidants by reaction with the electrogenerated halogens. On contrary, cationic surfactants gives significantly overstated results of antioxidants determination with electrogenerated hexacyanoferrate(III) ions. The use of surfactants in coulometry of {alpha}-tocopherol and retinol provides their solubilization and allows to perform titration in water media. Simple, express and reliable coulometric approach for determination of {alpha}-tocopherol, rutin and ascorbic acid in pharmaceuticals using surfactant media has been developed. The relative standard deviation of the

Fragment-based approach to calculate hydrophobicity of anionic and nonionic surfactants derived from chromatographic retention on a C18 stationary phase.

Science.gov (United States)

Hammer, Jort; Haftka, Joris J-H; Scherpenisse, Peter; Hermens, Joop L M; de Voogt, Pim W P

2017-02-01

To predict the fate and potential effects of organic contaminants, information about their hydrophobicity is required. However, common parameters to describe the hydrophobicity of organic compounds (e.g., octanol-water partition constant [K OW ]) proved to be inadequate for ionic and nonionic surfactants because of their surface-active properties. As an alternative approach to determine their hydrophobicity, the aim of the present study was therefore to measure the retention of a wide range of surfactants on a C 18 stationary phase. Capacity factors in pure water (k' 0 ) increased linearly with increasing number of carbon atoms in the surfactant structure. Fragment contribution values were determined for each structural unit with multilinear regression, and the results were consistent with the expected influence of these fragments on the hydrophobicity of surfactants. Capacity factors of reference compounds and log K OW values from the literature were used to estimate log K OW values for surfactants (log KOWHPLC). These log KOWHPLC values were also compared to log K OW values calculated with 4 computational programs: KOWWIN, Marvin calculator, SPARC, and COSMOThermX. In conclusion, capacity factors from a C 18 stationary phase are found to better reflect hydrophobicity of surfactants than their K OW values. Environ Toxicol Chem 2017;36:329-336. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

Early CPAP versus surfactant in extremely preterm infants.

Science.gov (United States)

Finer, Neil N; Carlo, Waldemar A; Walsh, Michele C; Rich, Wade; Gantz, Marie G; Laptook, Abbot R; Yoder, Bradley A; Faix, Roger G; Das, Abhik; Poole, W Kenneth; Donovan, Edward F; Newman, Nancy S; Ambalavanan, Namasivayam; Frantz, Ivan D; Buchter, Susie; Sánchez, Pablo J; Kennedy, Kathleen A; Laroia, Nirupama; Poindexter, Brenda B; Cotten, C Michael; Van Meurs, Krisa P; Duara, Shahnaz; Narendran, Vivek; Sood, Beena G; O'Shea, T Michael; Bell, Edward F; Bhandari, Vineet; Watterberg, Kristi L; Higgins, Rosemary D

2010-05-27

There are limited data to inform the choice between early treatment with continuous positive airway pressure (CPAP) and early surfactant treatment as the initial support for extremely-low-birth-weight infants. We performed a randomized, multicenter trial, with a 2-by-2 factorial design, involving infants who were born between 24 weeks 0 days and 27 weeks 6 days of gestation. Infants were randomly assigned to intubation and surfactant treatment (within 1 hour after birth) or to CPAP treatment initiated in the delivery room, with subsequent use of a protocol-driven limited ventilation strategy. Infants were also randomly assigned to one of two target ranges of oxygen saturation. The primary outcome was death or bronchopulmonary dysplasia as defined by the requirement for supplemental oxygen at 36 weeks (with an attempt at withdrawal of supplemental oxygen in neonates who were receiving less than 30% oxygen). A total of 1316 infants were enrolled in the study. The rates of the primary outcome did not differ significantly between the CPAP group and the surfactant group (47.8% and 51.0%, respectively; relative risk with CPAP, 0.95; 95% confidence interval [CI], 0.85 to 1.05) after adjustment for gestational age, center, and familial clustering. The results were similar when bronchopulmonary dysplasia was defined according to the need for any supplemental oxygen at 36 weeks (rates of primary outcome, 48.7% and 54.1%, respectively; relative risk with CPAP, 0.91; 95% CI, 0.83 to 1.01). Infants who received CPAP treatment, as compared with infants who received surfactant treatment, less frequently required intubation or postnatal corticosteroids for bronchopulmonary dysplasia (Pneonatal outcomes did not differ significantly between the two groups. The results of this study support consideration of CPAP as an alternative to intubation and surfactant in preterm infants. (ClinicalTrials.gov number, NCT00233324.) 2010 Massachusetts Medical Society

Masking of endotoxin in surfactant samples: Effects on Limulus-based detection systems.

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Reich, Johannes; Lang, Pierre; Grallert, Holger; Motschmann, Hubert

2016-09-01

Over the last few decades Limulus Amebocyte Lysate (LAL) has been the most sensitive method for the detection of endotoxins (Lipopolysaccharides) and is well accepted in a broad field of applications. Recently, Low Endotoxin Recovery (LER) in biopharmaceutical drug products has been noticed, whereby the detection of potential endotoxin contaminations is not ensured. Notably, most of these drug products contain surfactants, which can have crucial effects on the detectability of endotoxin. In order to analyze the driving forces of LER, endotoxin detection in samples containing nonionic surfactants in various buffer systems was investigated. The results show that the process of LER is kinetically controlled and temperature-dependent. Furthermore, only the simultaneous presence of nonionic surfactants and components capable of forming metal complexes resulted in LER. In addition, capacity experiments show that even hazardous amounts of endotoxin can remain undetectable within such formulation compositions. In conclusion, the LER phenomenon is caused by endotoxin masking and not by test interference. In this process, the supramolecular structure of endotoxin is altered and exhibits only a limited susceptibility in binding to the Factor C of Limulus-based detection systems. We propose a two-step mechanism of endotoxin masking by complex forming agents and nonionic surfactants. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Batch Test Screening of Industrial Product/Byproduct Filter Materials for Agricultural Drainage Water Treatment

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Barry J. Allred

2017-10-01

Full Text Available Filter treatment may be a viable means for removing the nitrate (NO3−, phosphate (PO43−, and pesticides discharged with agricultural drainage waters that cause adverse environmental impacts within the U.S. on local, regional, and national scales. Laboratory batch test screening for agricultural drainage water treatment potential was conducted on 58 industrial product/byproduct filter materials grouped into six categories: (1 high carbon content media; (2 high iron content media; (3 high aluminum content media; (4 surfactant modified clay/zeolite; (5 coal combustion residuals; and (6 spent foundry sands. Based on a percent contaminant removal criteria of 75% or greater, seven industrial products/byproducts were found to meet this standard for NO3− alone, 44 met this standard for PO43−, and 25 met this standard for the chlorinated triazine herbicide, atrazine. Using a 50% or greater contaminant removal criteria, five of the industrial product/byproduct filter materials exhibited potential for removing NO3−, PO43−, and atrazine together; eight showed capability for combined NO3− and PO43− removal; 21 showed capability for combined PO43− and atrazine removal; and nine showed capability for combined NO3− and atrazine removal. The results of this study delineated some potential industrial product/byproduct filter materials for drainage water treatment; however, a complete feasibility evaluation for drainage water treatment of any of these filter materials will require much more extensive testing.

Effects of reaction conditions on nuclear laundry water treatment in Fenton process

International Nuclear Information System (INIS)

Vilve, Miia; Hirvonen, Arja; Sillanpaeae, Mika

2009-01-01

This study presents the efficiency of Fenton process in the degradation of organic compounds of nuclear laundry water. The influence of Fe 2+ and hydrogen peroxide ratio, hydrogen peroxide dose, pH and treatment time were investigated. The degradation of non-ionic surfactant and other organic compounds was analysed as COD, TOC and molecular weight distribution (MWD). The most cost-effective degradation conditions were at H 2 O 2 /Fe 2+ stoichiometric molar ratio of 2 with 5 min mixing and H 2 O 2 dose of 1000 mg l -1 . With the initial pH of 6, the reductions of COD and TOC were 85% and 69%, respectively. However, the removal of the organic compounds was mainly carried out by Fenton-based Fe 3+ coagulation rather than Fenton oxidation. Fenton process proved to be much more efficient than previously performed ozone-based oxidation processes.

Partition thermodynamics of ionic surfactants between phosphatidylcholine vesicle and water phases

Science.gov (United States)

Chu, Shin-Chi; Hung, Chia-Hui; Wang, Shun-Cheng; Tsao, Heng-Kwong

2003-08-01

The partition of ionic surfactants (sodium alkyl sulfate and alkyl trimethyl ammonium bromide) between phosphatidylcholine vesicles and aqueous phase is investigated by simple conductometry under different temperatures. The experimental results can be well represented by the proposed regular solution theory and the thermodynamic parameters satisfy the thermodynamic consistency. The deviation from ideal partition is manifested through the effective interaction energy between lipid and surfactant wb, which is O(kT) large. It is found that wb rises as the alkyl chain is decreased for a specified head group. This is attributed to significant mismatch of chain lengths between surfactant and lipid molecules. The partition coefficient K declines with increasing temperature. The energy barrier from bilayer to aqueous phase, Δμ/kT∝ln K, is in the range of 16-26 kJ/mol. As the alkyl chain length is decreased for a given head group, Δμ is lowered by 1.3-1.5 kJ/mol per methylene group. Two independent analyses are employed to confirm this result. Using the thermodynamic parameters determined from experiments, the internal energy, entropy, and free energy of the partition process can be derived. Partition is essentially driven by the internal energy gain. The solubilizing ability, which is represented by the maximum surfactant-lipid ratio in the bilayer, Reb also decreases in accord with the K parameter. It is because the change in temperature influences the surfactant incorporation into the bilayer more than the formation of micelles.

Comparison of the orogenic displacement of sodium caseinate with the caseins from the air-water interface by nonionic surfactants.

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Woodward, N C; Gunning, A P; Mackie, A R; Wilde, P J; Morris, V J

2009-06-16

Displacement of sodium caseinate from the air-water interface by nonionic surfactants Tween 20 and Tween 60 was observed by atomic force microscopy (AFM). The interfacial structure was sampled by Langmuir-Blodgett deposition onto freshly cleaved mica substrates. Protein displacement occurred through an orogenic mechanism: it involved the nucleation and growth of surfactant domains within the protein network, followed by failure of the protein network. The surface pressure at which failure of the protein network occurred was essentially independent of the type of surfactant. The major component of sodium caseinate is beta-casein, and previous studies at the air-water interface have shown that beta-casein networks are weak, failing at surface pressures below that observed for sodium caseinate. The other components of sodium caseinate are alpha(s)- and kappa-caseins. Studies of the displacement of alpha(s)-caseins from air-water interfaces show that these proteins also form weak networks that fail at surface pressures below that observed for sodium caseinate. However, kappa-casein was found to form strong networks that resisted displacement and failed at surface pressures comparable to those observed for sodium caseinate. The AFM images of the displacement suggest that, despite kappa-casein being a minor component, it dominates the failure of sodium caseinate networks: alpha(s)-casein and beta-casein are preferentially desorbed at lower surface pressures, allowing the residual kappa-casein to control the breakdown of the sodium caseinate network at higher surface pressures.

Use of surfactants for the remediation of contaminated soils: a review.

Science.gov (United States)

Mao, Xuhui; Jiang, Rui; Xiao, Wei; Yu, Jiaguo

2015-03-21

Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation. Copyright © 2014 Elsevier B.V. All rights reserved.

Performance improvement of ionic surfactant flooding in carbonate rock samples by use of nanoparticles

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Mohammad Ali Ahmadi

2016-07-01

Full Text Available Abstract Various surfactants have been used in upstream petroleum processes like chemical flooding. Ultimately, the performance of these surfactants depends on their ability to reduce the interfacial tension between oil and water. The surfactant concentration in the aqueous solution decreases owing to the loss of the surfactant on the rock surface in the injection process. The main objective of this paper is to inhibit the surfactant loss by means of adding nanoparticles. Sodium dodecyl sulfate and silica nanoparticles were used as ionic surfactant and nanoparticles in our experiments, respectively. AEROSIL® 816 and AEROSIL® 200 are hydrophobic and hydrophilic nanoparticles. To determine the adsorption loss of the surfactant onto rock samples, a conductivity approach was used. Real carbonate rock samples were used as the solid phase in adsorption experiments. It should be noted that the rock samples were water wet. This paper describes how equilibrium adsorption was investigated by examining adsorption behavior in a system of carbonate sample (solid phase and surfactant solution (aqueous phase. The initial surfactant and nanoparticle concentrations were 500–5000 and 500–2000 ppm, respectively. The rate of surfactant losses was extremely dependent on the concentration of the surfactant in the system, and the adsorption of the surfactant decreased with an increase in the nanoparticle concentration. Also, the hydrophilic nanoparticles are more effective than the hydrophobic nanoparticles.

The Accelerated Late Adsorption of Pulmonary Surfactant

OpenAIRE

Loney, Ryan W.; Anyan, Walter R.; Biswas, Samares C.; Rananavare, Shankar B.; Hall, Stephen B.

2011-01-01

Adsorption of pulmonary surfactant to an air−water interface lowers surface tension (γ) at rates that initially decrease progressively, but which then accelerate close to the equilibrium γ. The studies here tested a series of hypotheses concerning mechanisms that might cause the late accelerated drop in γ. Experiments used captive bubbles and a Wilhelmy plate to measure γ during adsorption of vesicles containing constituents from extracted calf surfactant. The faster fall in γ reflects faster...

Influence of surfactants in forced dynamic dewetting.

Science.gov (United States)

Henrich, Franziska; Fell, Daniela; Truszkowska, Dorota; Weirich, Marcel; Anyfantakis, Manos; Nguyen, Thi-Huong; Wagner, Manfred; Auernhammer, Günter K; Butt, Hans-Jürgen

2016-09-20

In this work we show that the forced dynamic dewetting of surfactant solutions depends sensitively on the surfactant concentration. To measure this effect, a hydrophobic rotating cylinder was horizontally half immersed in aqueous surfactant solutions. Dynamic contact angles were measured optically by extrapolating the contour of the meniscus to the contact line. Anionic (sodium 1-decanesulfonate, S-1DeS), cationic (cetyl trimethylammonium bromide, CTAB) and nonionic surfactants (C 4 E 1 , C 8 E 3 and C 12 E 5 ) with critical micelle concentrations (CMCs) spanning four orders of magnitude were used. The receding contact angle in water decreased with increasing velocity. This decrease was strongly enhanced when adding surfactant, even at surfactant concentrations of 10% of the critical micelle concentration. Plots of the receding contact angle-versus-velocity almost superimpose when being plotted at the same relative concentration (concentration/CMC). Thus the rescaled concentration is the dominating property for dynamic dewetting. The charge of the surfactants did not play a role, thus excluding electrostatic effects. The change in contact angle can be interpreted by local surface tension gradients, i.e. Marangoni stresses, close to the three-phase contact line. The decrease of dynamic contact angles with velocity follows two regimes. Despite the existence of Marangoni stresses close to the contact line, for a dewetting velocity above 1-10 mm s -1 the hydrodynamic theory is able to describe the experimental results for all surfactant concentrations. At slower velocities an additional steep decrease of the contact angle with velocity was observed. Particle tracking velocimetry showed that the flow profiles do not differ with and without surfactant on a scales >100 μm.

Model study of enhanced oil recovery by flooding with aqueous surfactant solution and comparison with theory.

Science.gov (United States)

Fletcher, Paul D I; Savory, Luke D; Woods, Freya; Clarke, Andrew; Howe, Andrew M

2015-03-17

With the aim of elucidating the details of enhanced oil recovery by surfactant solution flooding, we have determined the detailed behavior of model systems consisting of a packed column of calcium carbonate particles as the porous rock, n-decane as the trapped oil, and aqueous solutions of the anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT). The AOT concentration was varied from zero to above the critical aggregation concentration (cac). The salt content of the aqueous solutions was varied to give systems of widely different, post-cac oil-water interfacial tensions. The systems were characterized in detail by measuring the permeability behavior of the packed columns, the adsorption isotherms of AOT from the water to the oil-water interface and to the water-calcium carbonate interface, and oil-water-calcium carbonate contact angles. Measurements of the percent oil recovery by pumping surfactant solutions into calcium carbonate-packed columns initially filled with oil were analyzed in terms of the characterization results. We show that the measured contact angles as a function of AOT concentration are in reasonable agreement with those calculated from values of the surface energy of the calcium carbonate-air surface plus the measured adsorption isotherms. Surfactant adsorption onto the calcium carbonate-water interface causes depletion of its aqueous-phase concentration, and we derive equations which enable the concentration of nonadsorbed surfactant within the packed column to be estimated from measured parameters. The percent oil recovery as a function of the surfactant concentration is determined solely by the oil-water-calcium carbonate contact angle for nonadsorbed surfactant concentrations less than the cac. For surfactant concentrations greater than the cac, additional oil removal occurs by a combination of solubilization and emulsification plus oil mobilization due to the low oil-water interfacial tension and a pumping pressure increase.

Influence of stability of polymer surfactant on oil displacement mechanism

Science.gov (United States)

Liu, Li; Li, Chengliang; Pi, Yanming; Wu, Di; He, Ying; Geng, Liang

2018-02-01

At present, most of the oilfields of China have entered the late stage of high water-cut development, and three oil recovery technique has become the leading technology for improving oil recovery. With the improvement of three oil recovery techniques, the polymer surfactant flooding technology has been widely promoted in oil fields in recent years. But in the actual field experiment, it has been found that the polymer surfactant has chromatographic separation at the extraction end, which indicates that the property of the polymer surfactant has changed during the displacement process. At present, there was few literature about how the stability of polymer surfactant affects the oil displacement mechanism. This paper used HuaDing-I polymer surfactant to conduct a micro photolithography glass flooding experiment, and then compared the oil displacement law of polymer surfactant before and after static setting. Finally, the influence law of stability of polymer surfactant on the oil displacement mechanism is obtained by comprehensive analysis.

Removal of cationic surfactant (CTAB from aqueous solution on to activated carbon obtained from corncob.

Directory of Open Access Journals (Sweden)

S. M. Yakout

2009-05-01

Full Text Available Direct and indirect releases of large quantities of surfactants to the environment may result in serious health and environmental problems. Therefore, surfactants should be removed from water before water is released to the environment or delivered for public use. Using powdered activated carbon (PAC as adsorbent may be an effective technique to remove surfactants. In this study, the removal of surfactants by PAC was investigated and the influencesof the operating parameters on the effectiveness on adsorption rate were studied. Cationic surfactant, Cetyl trimethyl ammonium bromide (CTAB was selected for the experiments. A series of batch experiments were performed to determine the sorption isotherms of surfactants to PAC. The results showed that carbon structure affect mainly on the surfactant adsorption. Surfactant equilibrium data fitted very well to the binary langmuir model. The pseudo first-,second- order and intraparticle diffusion kinetic models were applied. Both, the external mass transfer and intraparticle diffusion mechanisms involve in CTAB sorption.

Acid-base, optical and extraction properties of Rose Bengal in the presence of surfactants

International Nuclear Information System (INIS)

Lengyel, J.; Krtil, J.; Kuban, V.

1989-01-01

Changes in the optical and acid-base characteristics of Rose Bengal in the presence of cationic (Septones - SPX, hexadecyltrimethylammonium bromide - CTMAB and hexadecylpyridinium bromide - CPB), anionic (sodium dodecylsuulfate - SDS) and nonionic (Triton X-100) surfactants in submicellar and micellar concentrations were studied spectrophotometrically. The conditional dissociation constants of Rose Bengal pK ai * depend on the kind and concentration of cationic surfactant. Changes in pK ai * values are described in terms of formation of ion associates of the dye with the surfactant of the composition QHB and Q 2 B. The extraction constants of the ion associates in chloroform were determined radiometrically with the aid of Rose Bengal labelled with 131 I. (author). 4 figs., 3 tabs., 22 refs

The Potential of a Surfactant/Polymer Flood in a Middle Eastern Reservoir

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Meshal Algharaib

2012-01-01

Full Text Available An integrated full-field reservoir simulation study has been performed to determine the reservoir management and production strategies in a mature sandstone reservoir. The reservoir is a candidate for an enhanced oil recovery process or otherwise subject to abandonment. Based on its charateristics, the reservoir was found to be most suited for a surfactant/polymer (SP flood. The study started with a large data gathering and the building of a full-field three-dimensional geological model. Subsequently, a full field simulation model was built and used to history match the water flood. The history match of the water flood emphasizes the areas with remaining high oil saturations, establishes the initial condition of the reservoir for an SP flood, and generates a forecast of reserves for continued water flood operations. A sector model was constructed from the full field model and then used to study different design parameters to maximize the project profitability from the SP flood. An economic model, based on the estimated recovery, residual oil in-place, oil price, and operating costs, has been implemented in order to optimize the project profitability. The study resulted in the selection of surfactant and polymer concentrations and slug size that yielded the best economic returns when applied in this reservoir. The study shows that, in today’s oil prices, surfactant/polymer flood when applied in this reservoir has increased the ultimate oil recovery and provide a significant financial returns.

The effect of surfactant on pollutant biosorption of Trametes versicolor

Science.gov (United States)

Gül, Ülküye Dudu; Silah, Hülya; Akbaş, Halide; Has, Merve

2016-04-01

The major problem concerning industrial wastewater is treatment of dye and heavy metal containing effluents. Industrial effluents are also contained surfactants that are used as levelling, dispersing and wetting agents. The purpose of this study was to investigate the effect of surfactant on textile dye biosorption properties of a white rot fungus named Trametes versicolor. Reactive dyes are commonly used in textile industry because of their advantages such as brightness and excellent color fastness. A recative textile dye, called Everzol Black, was used in this study. The low-cost mollasses medium is used for fungal growth. The usage of mollases, the sugar refinery effluent as a source of energy and nutrients, gained importance because of reducing the cost and also reusing another waste. In biosorption process the effect of surfactant on dye removal properties of T. versicolor was examined as a function of pH, dye consentration and surfactant concentration. The results of this study showed that the surfactant enhanced the dye removal capacity of Trametes versicolor. The dye and surfactant molecules were interacted electrostatically and these electrostatic interactions improved dye removal properties of filamentous fungus T. versicolor. The results of this study recommended the use of surfactants as an inducer in textile wastewater treatment technologies.

Surfactants tailored by the class Actinobacteria

Science.gov (United States)

Kügler, Johannes H.; Le Roes-Hill, Marilize; Syldatk, Christoph; Hausmann, Rudolf

2015-01-01

Globally the change towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application. PMID:25852670

Surfactants tailored by the class Actinobacteria

Directory of Open Access Journals (Sweden)

Johannes H Kügler

2015-03-01

Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.

Foaming behaviour of polymer-surfactant solutions

International Nuclear Information System (INIS)

Cervantes-MartInez, Alfredo; Maldonado, Amir

2007-01-01

We study the effect of a non-ionic amphiphilic polymer (PEG-100 stearate also called Myrj 59) on the foaming behaviour of aqueous solutions of an anionic surfactant (sodium dodecyl sulfate or SDS). The SDS concentration was kept fixed while the Myrj 59 concentration was varied. Measurements of foamability, surface tension and electrical conductivity were carried out. The results show two opposite effects depending on the polymer concentration: foamability is higher when the Myrj 59 concentration is low; however, it decreases considerably when the polymer concentration is increased. This behaviour is due to the polymer adsorption at the air/liquid interface at lower polymer concentrations, and to the formation of a polymer-surfactant complex in the bulk at higher concentrations. The results are confirmed by surface tension and electrical conductivity measurements, which are interpreted in terms of the microstructure of the polymer-surfactant solutions. The observed behaviour is due to the amphiphilic nature of the studied polymer. The increased hydrophobicity of Myrj 59, compared to that of water-soluble polymers like PEG or PEO, increases its 'reactivity' towards SDS, i.e. the strength of its interaction with this anionic surfactant. Our results show that hydrophobically modified polymers have potential applications as additives in order to control the foaming properties of surfactant solutions

Magnetic surfactants as molecular based-magnets with spin glass-like properties

International Nuclear Information System (INIS)

Brown, Paul; Hatton, T Alan; Smith, Gregory N; Hernández, Eduardo Padrón; James, Craig; Eastoe, Julian; Nunes, Wallace C; Settens, Charles M; Baker, Peter J

2016-01-01

This paper reports the use of muon spin relaxation spectroscopy to study how the aggregation behavior of magnetic surfactants containing lanthanide counterions may be exploited to create spin glass-like materials. Surfactants provide a unique approach to building in randomness, frustration and competing interactions into magnetic materials without requiring a lattice of ordered magnetic species or intervening ligands and elements. We demonstrate that this magnetic behavior may also be manipulated via formation of micelles rather than simple dilution, as well as via design of surfactant molecular architecture. This somewhat unexpected result indicates the potential of using novel magnetic surfactants for the generation and tuning of molecular magnets. (paper)

Behavior of microemulsion systems of virgin coconut oil (VCO) using igepal CO-520 and tween 80 surfactant

Science.gov (United States)

Safuan, A.; Hamdan, S.; Laili, C. R.

2017-09-01

Virgin Coconut Oil (VCO) has been applied in many application and products. Formation of microemulsion region with surfactant was investigated by using phase diagram. The surfactants used are igepal CO-520 and tween 80. The studies showed that formation of microemulsion region were dependent on the behaviour of the surfactant toward VCO. The result showed that microemulsion regions were present in igepal CO-520 system formed a larger water-in-oil microemulsion region compared to tween 80 system. Certain weight ratios of VCO to surfactants were studied by using evaporation test in order to study the water loss of the microemulsion in ambient condition. The evaporation rate of samples was varies depending their compositon of VCO, surfactant and water.

Synthesis and characterization of zeolite material from coal ashes modified by surfactant

International Nuclear Information System (INIS)

Fungaro, D.A.; Borrely, S.I.

2010-01-01

Coal ash was used as starting material for zeolite synthesis by means of hydrothermal treatment. The surfactant-modified zeolite (SMZ) was prepared by adsorbing the cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) on the external surface of the zeolite from coal ash. The zeolite structure stability was monitored during the characterization of the materials by FTIR, XDR and SEM. The structural parameters of surfactant-modified zeolite are very close to that of corresponding non-modified zeolite which indicates that the crystalline nature of the zeolite remained intact after required chemical treatment with HDTMA-Br molecules and heating treatment for drying. The most intense peaks in the FTIR spectrum of HDTMA-Br were observed in SMZ spectrum confirming adsorption of surfactant on zeolites. (author)

Micellar solubilization in strongly interacting binary surfactant systems. [Binary surfactant systems of: dodecyltrimethylammonium chloride + sodium dodecyl sulfate; benzyldimethyltetradecylammonium chloride + tetradecyltrimethylammonium chloride

Energy Technology Data Exchange (ETDEWEB)

Treiner, C. (Universite Pierre et Marie Curie, Paris (France)); Nortz, M.; Vaution, C. (Faculte de Pharmacie de Paris-sud, Chatenay-Malabry (France))

1990-07-01

The apparent partition coefficient P of barbituric acids between micelles and water has been determined in mixed binary surfactant solutions from solubility measurements in the whole micellar composition range. The binary systems chosen ranged from the strongly interacting system dodecyltrimethylammonium chloride + sodium dodecyl sulfate to weakly interacting systems such as benzyldimethyltetradecylammonium chloride + tetradecyltrimethyammonium chloride. In all cases studied, mixed micelle formation is unfavorable to micellar solubilization. A correlation is found between the unlike surfactants interaction energy, as measured by the regular solution parameter {beta} and the solute partition coefficient change upon surfactant mixing. By use of literature data on micellar solubilization in binary surfactant solutions, it is shown that the change of P for solutes which are solubilized by surface adsorption is generally governed by the sign and amplitude of the interaction parameter {beta}.

Double salts of ionic-liquid-based surfactants in microextraction: application of their mixed hemimicelles as novel sorbents in magnetic-assisted micro-dispersive solid-phase extraction for the determination of phenols.

Science.gov (United States)

Trujillo-Rodríguez, María J; Pino, Verónica; Anderson, Jared L; Ayala, Juan H; Afonso, Ana M

2015-11-01

The use of mixed hemimicelles of ionic liquid (IL)-based surfactants in a magnetic-based micro-dispersive solid-phase extraction (m-μdSPE) approach is described. Not only is the symmetric monocationic IL-based surfactant 1,3-didodecylimidazolium bromide (C12C12Im-Br) studied for first time in m-μdSPE, but double-salt (DS) IL (DSIL)-based surfactants are also examined. Nine DSIL-based surfactants were formed by combination of C12C12Im-Br with other IL-based surfactants, including nonsymmetric monocationic and dicationic ILs combined at three different molar fractions. The analytical application was focused on the determination of a group of eight phenols, including bisphenol A, in water samples. The best results were obtained with the DSIL formed by C12C12Im-Br (molar fraction 0.5) and 1-hexadecyl-3-methylimidazolium bromide (C16MIm-Br), after proper optimization of the overall method in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD). The optimum conditions for 100 mL of water samples require a small amount (10 mg) of Fe3O4 magnetic nanoparticles, a low content (5.0 mg of C12C12Im-Br and 3.9 mg of C16MIm-Br) of the selected DSIL, pH 11, a sonication time of 2.5 min, and an equilibration time of 5 min with the aid of NdFeB magnets, followed by elution of phenols, evaporation, and reconstitution with 0.5 mL of acetonitrile. The overall m-μdSPE-HPLC-DAD method is characterized for limits of detection down to 1.3 μg · L(-1), intraday relative standard deviations lower than 13 % (n = 3), and interday relative standard deviations lower than 17 % (n = 9), with a spiking level of 15 μg · L(-1); with enrichment factors between 15.7 and 141, and average relative recoveries of 99.9 %.

A numerical study of the life time of superficial bubbles in water-alcohol mixtures with surfactants

Science.gov (United States)

Atasi, Omer; Scheid, Benoit; Haut, Benoît; Legendre, Dominique; Zenit, Roberto

2017-11-01

The evaluation of the lifetime of bubbles at the surface of a liquid has been used as an empirical technique in the traditional production of Mezcal (an artisanal distilled agave spirit from Mexico) to determine the desired concentration of alcohol. We investigated this problem in light of computational fluid dynamics (CFD) using a level-set method and a scalar transport technique to account for the presence of surfactants. We determined the rupture time of the film at the top of a bubble in function of the various bulk and surface properties. In agreement with experiments, we found that the superficial bubbles exhibit an extended lifetime for an intermediate water-alcohol concentration, corresponding to both a maximum of viscosity and a specific concentration of surfactants. We finally propose a scaling law that should be of practical use for Mezcal production. F.R.S-FNRS.

Surfactant-Enhanced Size-Excluded Transport of Bacteria Through Unsaturated Porous Media.

Science.gov (United States)

Zhu, J.

2017-12-01

US domestic waste water is rich in surfactants because of the intensive usage of surfactants-containing household product. It results in a surfactants presence environment when this untreated waste water released into subsurface. It was reported that surfactants enhance the colloidal transport in porous media, which have significant effect on issues such as subsurface pathogens contamination and biodegradation. In this study, soil column experiments were conducted. The soil column was remained unsaturated and with a steady flow passing through it. Escherichia coli K-12 transported in the soil column and its breakthrough data was collected in presence of surfactant anionic surfactant linear alkylbenzene sulfonate (LAS) concentration range over 0, 0.25, 0.5, 0.75, 1, and 2 times Critical Micelle Concentration (CMC). It was found that the increase in LAS concentration greatly increases breakthrough concentration C/C0 and decreases breakthrough time tb until LAS concentration reaches 1 xCMC. Numerical models were built simulating and investigating this phenomenon. The goodness of model fitting was greatly improved by adding exclusion factor into the model, which indicated that the presence of surfactant might enhance the exclusion effect. The relationships between LAS concentration and the two coefficients, deposition rate coefficient k and exclusion effect coefficient θim, were found can be fitted by a quasi-Langmuir equation. And the model validation with observed data showed that the model has an acceptable reliability.

Potential exposure and treatment efficiency of nanoparticles in water supplies based on wastewater reclamation

DEFF Research Database (Denmark)

Kirkegaard, Peter; Hansen, Steffen Foss; Rygaard, Martin

2015-01-01

Water scarcity brings an increased focus on wastewater reclamation for drinking water supply. Meanwhile, the production volume of nanoparticles (NPs) is rapidly increasing, but to date there has been little attention given to the fate of NPs in water systems based on wastewater reclamation. We have...... investigated the possible concentrations of silver (Ag), titanium dioxide (TiO2), and zinc oxide (ZnO) nanoparticles in tap water for water supplies based on reclaimed wastewater. Tap water concentrations of the NPs were assessed by mass flow analyses of two typical wastewater reclamation concepts: 1) advanced...... studies are available on the removal efficiencies of NPs by advanced water treatment processes with a majority of the identified studies focusing on removal efficiencies in wastewater treatment plants and fate in surface waters. The NP removal efficiency of several treatment processes is unknown...

History of surfactant up to 1980.

Science.gov (United States)

Obladen, Michael

2005-01-01

Remarkable insight into disturbed lung mechanics of preterm infants was gained in the 18th and 19th century by the founders of obstetrics and neonatology who not only observed respiratory failure but also designed devices to treat it. Surfactant research followed a splendid and largely logical growth curve. Pathological changes in the immature lung were characterized in Germany by Virchow in 1854 and by Hochheim in 1903. The Swiss physiologist von Neergard fully understood surfactant function in 1929, but his paper was ignored for 25 years. The physical properties of surfactant were recognized in the early 1950s from research on warfare chemicals by Pattle in Britain and by Radford and Clements in the United States. The causal relationship of respiratory distress syndrome (RDS) and surfactant deficiency was established in the USA by Avery and Mead in 1959. The Australian obstetrician Liggins induced lung maturity with glucocorticoids in 1972, but his discovery was not fully believed for another 20 years. A century of basic research was rewarded when Fujiwara introduced surfactant substitution in Japan in 1980 for treatment and prevention of RDS. Copyright 2005 S. Karger AG, Basel

A highly accurate boundary integral equation method for surfactant-laden drops in 3D

Science.gov (United States)

Sorgentone, Chiara; Tornberg, Anna-Karin

2018-05-01

The presence of surfactants alters the dynamics of viscous drops immersed in an ambient viscous fluid. This is specifically true at small scales, such as in applications of droplet based microfluidics, where the interface dynamics become of increased importance. At such small scales, viscous forces dominate and inertial effects are often negligible. Considering Stokes flow, a numerical method based on a boundary integral formulation is presented for simulating 3D drops covered by an insoluble surfactant. The method is able to simulate drops with different viscosities and close interactions, automatically controlling the time step size and maintaining high accuracy also when substantial drop deformation appears. To achieve this, the drop surfaces as well as the surfactant concentration on each surface are represented by spherical harmonics expansions. A novel reparameterization method is introduced to ensure a high-quality representation of the drops also under deformation, specialized quadrature methods for singular and nearly singular integrals that appear in the formulation are evoked and the adaptive time stepping scheme for the coupled drop and surfactant evolution is designed with a preconditioned implicit treatment of the surfactant diffusion.

Effects of various surfactants on the dispersion stability and electrical conductivity of surface modified graphene

Energy Technology Data Exchange (ETDEWEB)

Uddin, Md. Elias [WCU Program, Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kuila, Tapas [Surface Engineering and Tribology, CSIR – Central Mechanical Engineering Research Institute, Durgapur 721 302 (India); Nayak, Ganesh Chandra [Department of Applied Chemistry, ISM Dhanbad, Dhanbad 826 004, Jharkhand (India); Kim, Nam Hoon [Department of Hydrogen and Fuel Cell Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Ku, Bon-Cheol [Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Dunsan-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 864-9 (Korea, Republic of); Lee, Joong Hee, E-mail: jhl@chonbuk.ac.kr [WCU Program, Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Department of Hydrogen and Fuel Cell Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

2013-06-15

Highlights: ► Water dispersible graphene has been prepared using ionic and non-ionic surfactants. ► XPS and FTIR spectra analysis confirm surface modification and reduction of GO. ► The highest water dispersibility is observed in the graphene modified with of SDBS. ► The best properties of modified graphene is achieved with GO/surfactant ratio of two. -- Abstract: Ionic and non-ionic surfactant functionalized, water dispersible graphene were prepared to investigate the effects on the dispersion stability and electrical conductivity of graphene. In this study, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate and 4-(1,1,3,3-tetramethylbutyl) phenyl-polyethylene glycol (Triton X-100) were used as ionic and non-ionic surfactants. The effects of surfactant concentrations on the dispersibility and electrical conductivity of the surface modified graphene were investigated. The dispersion stability of SDBS functionalized graphene (SDBS-G) was found to be best in water at 1.5 mg ml{sup −1}. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis indicate that the presence of surfactants does not prevent the reduction of graphene oxide (GO). These measurements also demonstrated that the surfactants were present on the surface of graphene, resulting in the formation of functionalized graphene. The thickness of different functionalized graphene was measured by Atomic force microscopy and varied significantly with different surfactants. The thermal properties of the functionalized graphene were also found to be dependent on the nature of the surfactants. The electrical conductivity of SDBS-G (108 S m{sup −1}) was comparatively higher than SDS and Triton X-100 functionalized graphene.

Effect of surfactant and partial liquid ventilation treatment on gas exchange and lung mechanics in immature lambs: influence of gestational age.

Science.gov (United States)

Rey-Santano, Carmen; Mielgo, Victoria; Gastiasoro, Elena; Valls-i-Soler, Adolfo; Murgia, Xabier

2013-01-01

Surfactant (SF) and partial liquid ventilation (PLV) improve gas exchange and lung mechanics in neonatal RDS. However, variations in the effects of SF and PLV with degree of lung immaturity have not been thoroughly explored. Experimental Neonatal Respiratory Physiology Research Unit, Cruces University Hospital. Prospective, randomized study using sealed envelopes. 36 preterm lambs were exposed (at 125 or 133-days of gestational age) by laparotomy and intubated. Catheters were placed in the jugular vein and carotid artery. All the lambs were assigned to one of three subgroups given: 20 mL/Kg perfluorocarbon and managed with partial liquid ventilation (PLV), surfactant (Curosurf®, 200 mg/kg) or (3) no pulmonary treatment (Controls) for 3 h. Cardiovascular parameters, blood gases and pulmonary mechanics were measured. In 125-day gestation lambs, SF treatment partially improved gas exchange and lung mechanics, while PLV produced significant rapid improvements in these parameters. In 133-day lambs, treatments with SF or PLV achieved similarly good responses. Neither surfactant nor PLV significantly affected the cardiovascular parameters. SF therapy response was more effective in the older gestational age group whereas the effectiveness of PLV therapy was not gestational age dependent.

Effects of the conjugation of whey proteins with gellan polysaccharides on surfactant-induced competitive displacement from the air-water interface.

Science.gov (United States)

Cai, B; Ikeda, S

2016-08-01

Whey proteins can be used to stabilize foams and emulsions against coalescence because of their ability to form viscoelastic films at the interface that resist film rupture on collision between colloidal particles. However, whey proteins are competitively displaced from the interface if small-molecule surfactants are added, leading to destabilization of the entire system. This is because surfactants are more effective in molecular packing at the interface, and they lower interfacial tension to a greater degree than whey proteins do, but their interfacial films are poor in viscoelasticity. We hypothesized that whey proteins would become more resistant to surfactant-induced competitive displacement if they were conjugated with network-forming polysaccharides. The protein moiety of the conjugate would be expected to enable its adsorption to the interface, and the polysaccharide moiety would be expected to form self-assembled networks, strengthening the interfacial film as a whole. In this study, whey proteins were conjugated with gellan polysaccharides using the Maillard reaction. Atomic force microscopy images of interfacial films formed by the whey protein-gellan conjugate at the air-water interface and transferred onto mica sheets using the Langmuir-Blodgett method revealed that gellan did form self-assembled networks at the interface and that interfacial films also contained a large number of unconjugated whey protein molecules. Following the addition of a small-molecule surfactant (Tween 20) to the sub-phase, surface pressure increased, indicating spontaneous adsorption of surfactants to the interface. Atomic force microscopy images showed decreases in interfacial area coverage by whey proteins as surface pressure increased. At a given surface pressure, the interfacial area coverage by whey protein-gellan conjugates was greater than coverage by unconjugated whey proteins, confirming that whey proteins became more resistant to surfactant-induced displacement after

Surfactant-dependent macrophage response to polypyrrole-based coatings electrodeposited on Ti6Al7Nb alloy

Energy Technology Data Exchange (ETDEWEB)

Mindroiu, Mihaela [University Polytechnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061, Bucharest (Romania); Ion, Raluca [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095, Bucharest (Romania); Pirvu, Cristian [University Polytechnica of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu, 011061, Bucharest (Romania); Cimpean, Anisoara, E-mail: anisoara.cimpean@bio.unibuc.ro [University of Bucharest, Department of Biochemistry and Molecular Biology, 91-95 Spl. Independentei, 050095, Bucharest (Romania)

2013-08-01

In this study, polypyrrole (PPy) films were successfully synthesized on Ti6Al7Nb alloy by potentiostatic polymerization in the presence of poly(sodium 4-styrenesulfonate) (NaPSS), t-octylphenoxy polyethoxyethanol (Triton X-100) and N-dodecyl-β-D-maltoside (DM) surfactants. Atomic force microscopy (AFM) analysis of the PPy/surfactant composite films revealed a granular structure characterized by a lower surface roughness than un-modified PPy films. The results demonstrated that addition of surfactants, namely Triton X-100 and DM, can improve electrochemical film stability and corrosion resistance. Further, Triton X-100 enhanced the adhesive strength of PPy films to the substrate. The surfactant type also showed a great influence on the surface wettability, the highest hydrophilic character being observed in the case of PPy/PSS film. Few studies have been devoted to the elucidation of inflammatory cell response to PPy-based materials. Therefore, RAW 264.7 macrophages were cultured on PPy-surfactant films to determine whether they elicit a differential cell behavior in terms of cell adhesion, proliferation, cellular morphology and cytokine secretion. Our results highlight the dependence of macrophage response on the surfactants used in the pyrrole polymerization process and suggest that the immune response to biomaterials coated with PPy films might be controlled by the choice of surfactant molecules. Highlights: • We electrodeposited polypyrrole films on Ti6Al7Nb alloy using three surfactants. • Differences in electrostability and wettability of polypyrrole films were found. • Triton X increased and NaPSS decreased the adhesion of polypyrrole films to Ti6Al7Nb. • Cytoskeletal architecture and macrophage activation were affected by surfactants. • The hydrophilic PPy/PSS coating elicited the lowest inflammatory response.

Surfactant-dependent macrophage response to polypyrrole-based coatings electrodeposited on Ti6Al7Nb alloy

International Nuclear Information System (INIS)

Mindroiu, Mihaela; Ion, Raluca; Pirvu, Cristian; Cimpean, Anisoara

2013-01-01

In this study, polypyrrole (PPy) films were successfully synthesized on Ti6Al7Nb alloy by potentiostatic polymerization in the presence of poly(sodium 4-styrenesulfonate) (NaPSS), t-octylphenoxy polyethoxyethanol (Triton X-100) and N-dodecyl-β-D-maltoside (DM) surfactants. Atomic force microscopy (AFM) analysis of the PPy/surfactant composite films revealed a granular structure characterized by a lower surface roughness than un-modified PPy films. The results demonstrated that addition of surfactants, namely Triton X-100 and DM, can improve electrochemical film stability and corrosion resistance. Further, Triton X-100 enhanced the adhesive strength of PPy films to the substrate. The surfactant type also showed a great influence on the surface wettability, the highest hydrophilic character being observed in the case of PPy/PSS film. Few studies have been devoted to the elucidation of inflammatory cell response to PPy-based materials. Therefore, RAW 264.7 macrophages were cultured on PPy-surfactant films to determine whether they elicit a differential cell behavior in terms of cell adhesion, proliferation, cellular morphology and cytokine secretion. Our results highlight the dependence of macrophage response on the surfactants used in the pyrrole polymerization process and suggest that the immune response to biomaterials coated with PPy films might be controlled by the choice of surfactant molecules. Highlights: • We electrodeposited polypyrrole films on Ti6Al7Nb alloy using three surfactants. • Differences in electrostability and wettability of polypyrrole films were found. • Triton X increased and NaPSS decreased the adhesion of polypyrrole films to Ti6Al7Nb. • Cytoskeletal architecture and macrophage activation were affected by surfactants. • The hydrophilic PPy/PSS coating elicited the lowest inflammatory response

Control of stain geometry by drop evaporation of surfactant containing dispersions.

Science.gov (United States)

Erbil, H Yildirim

2015-08-01

Control of stain geometry by drop evaporation of surfactant containing dispersions is an important topic of interest because it plays a crucial role in many applications such as forming templates on solid surfaces, in ink-jet printing, spraying of pesticides, micro/nano material fabrication, thin film coatings, biochemical assays, deposition of DNA/RNA micro-arrays, and manufacture of novel optical and electronic materials. This paper presents a review of the published articles on the diffusive drop evaporation of pure liquids (water), the surfactant stains obtained from evaporating drops that do not contain dispersed particles and deposits obtained from drops containing polymer colloids and carbon based particles such as carbon nanotubes, graphite and fullerenes. Experimental results of specific systems and modeling attempts are discussed. This review also has some special subtopics such as suppression of coffee-rings by surfactant addition and "stick-slip" behavior of evaporating nanosuspension drops. In general, the drop evaporation process of a surfactant/particle/substrate system is very complex since dissolved surfactants adsorb on both the insoluble organic/inorganic micro/nanoparticles in the drop, on the air/solution interface and on the substrate surface in different extends. Meanwhile, surfactant adsorbed particles interact with the substrate giving a specific contact angle, and free surfactants create a solutal Marangoni flow in the drop which controls the location of the particle deposition together with the rate of evaporation. In some cases, the presence of a surfactant monolayer at the air/solution interface alters the rate of evaporation. At present, the magnitude of each effect cannot be predicted adequately in advance and consequently they should be carefully studied for any system in order to control the shape and size of the final deposit. Copyright © 2014 Elsevier B.V. All rights reserved.

Performance evaluation of non-ionic surfactant based tazarotene encapsulated proniosomal gel for the treatment of psoriasis.

Science.gov (United States)

Prasad, Vure; Chaurasia, Sundeep

2017-10-01

The study aims to explore the potential of non-ionic surfactant based proniosomal gel (PNG) in improving the topical delivery of tazarotene by in vitro and in vivo studies. The PNG was prepared using coacervation phase separation method composed of span, stearylamine, cholesterol, and lecithin. The PNG demonstrated favorable vesicle size (3.26±0.22μm) and percent encapsulation efficiency (49.50±2.3%). The PNG was evaluated for viscosity which indicated that the ratio of span:cholesterol:stearylamine (64.5:30.5:5mM) demonstrated no any fluctuations in viscosity. The scanning electron micrographs exhibited spherical vesicles with sharp boundaries. The in vitro drug release through cellulose membrane and rat's skin were found to be in the following order of the formulation code A2>A4>A3>A5 and A4>A2>A3>A5, respectively, which showed the prolonged release of entrapped tazarotene. Further, in vitro drug permeation and retention studies revealed that formulations A2 and A4 showed the higher percent of drug permeation whereas formulations A3 and A5 showed the higher percent of drug retention through rat's skin. Moreover, PNG A2 and A4 formulations demonstrated good stability characteristics at different temperature conditions. The stability in the presence of detergent revealed that no any abrupt change in turbidity. The skin irritation studies performed with formulations A2 and A4 showed no erythema compared with the plain PNG. The male Albino NMRI mice tail model was used to performed in vivo skin histological examination which revealed that an increase in the orthokeratosis strengthened. Thus, all the results concluded that surfactant, Span 60 based PNG formulations have shown a good ability to increase drug accumulation in the various skin layers and more potential carrier for topical delivery of tazarotene for an effective therapy of psoriasis. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of surfactant-free microemulsions and microemulsions with fatty acid salts

OpenAIRE

Marcus, Julien

2016-01-01

This thesis deals with the study of microemulsions and is composed of two main parts. In the first part, surfactant-free microemulsions are studied, whereas in the second part microemulsions with surfactants and cosurfactants are investigated. Over the last few years, surfactant-free microemulsions became a major topic at our institute and were thoroughly studied using the reference system water/ethanol/1-octanol. As explained later in the Fundamentals part (see section 1.2), fluctuating ...

Coupling surfactants with permanganate for DNAPL removal : coinjection or sequential application as delivery methods

Energy Technology Data Exchange (ETDEWEB)

Dugan, P.J. [Carus Corp., Peru, IL (United States); Siegrist, R.L. [Colorado School of Mines, Golden, CO (United States); Crimi, M.L. [Clarkson Univ., Potsdam, NY (United States)

2010-07-01

This PowerPoint presentation described a study conducted to test the effectiveness of surfactant-enhanced permanganate for the remediation of dense nonaqueous phase liquids (DNAPL). When DNAPL enters the environment, it can pollute millions of gallons of ground water and create huge dissolved plumes that act as long-term sources of contamination. Surfactants were used to enhance the solubilization and mobilization of DNAPL during the remediation process. In situ chemical oxidation (ISCO) was then used to deliver oxidants into the sub-surface to destroy organic contaminants in the soil and ground water. Experimental 2-D flow-through cell studies of 72 surfactants were conducted with the permanganate to evaluate delivery methods and determine compatible co-solvents for the surfactant process. Delivery methods included co-injection and sequential application. Four compatible surfactants were found to be compatible with the permanganate. A 90 percent DNAPL remediation rate was achieved using relatively low surfactant and oxidant concentrations. tabs., figs.

Understanding the Impact of Model Surfactants on Cloud Condensation Nuclei Activity of Sea Spray Aerosols

Science.gov (United States)

Forestieri, S.; Cappa, C. D.; Ruehl, C. R.; Bertram, T. H.; Staudt, S.; Kuborn, T.

2017-12-01

Aerosol impacts on cloud properties, also known as indirect effects, remain a major source of uncertainty in modeling global radiative forcing. Reducing this uncertainty necessitates better understanding of how aerosol chemical composition impacts the cloud-forming ability of aerosols. The presence of surfactants in aerosols can decrease the surface tension of activating droplets relative to water and lead to more efficient activation. The importance of this effect has been debated, but recent surface tension measurements of microscopic droplets indicate that surface tension is substantially depressed relative to water for lab-generated particles consisting of salt and a single organic species and for complex mixtures of organic matter. However, little work has been done on understanding how chemical complexity (i.e. interaction between different surfactant species) impacts surface tension for particles containing mixtures of surfactants. In this work, we quantified the surface tension of lab-generated aerosols containing surfactants that are commonly found in nascent sea spray aerosol (SSA) at humidities close to activation using a continuous flow stream-wise thermal gradient chamber (CFSTGC). Surface tension was quantified for particles containing single surfactant species and mixtures of these surfactants to investigate the role of chemical complexity on surface tension and molecular packing at the air-water interface. For all surfactants tested in this study, substantial surface tension depression (20-40 mN/m) relative to water was observed for particles containing large fractions of organic matter at humidities just below activation. However, the presence of these surfactants only weakly depressed surface tension at activation. Kinetic limitations were observed for particles coated with just palmitic acid, since palmitic acid molecules inhibit water uptake through their ability to pack tightly at the surface. However, these kinetic limitations disappeared when

Enhanced dispersion of boron nitride nanosheets in aqueous media by using bile acid-based surfactants

Science.gov (United States)

Chae, Ari; Park, Soo-Jin; Min, Byunggak; In, Insik

2018-01-01

Facile noncovalent surface functionalization of hydroxylated boron nitride nanosheet (BNNS-OH) was attempted through the sonication-assisted exfoliation of h-BN in aqueous media in the presence of bile acid-based surfactants such as sodium cholic acid (SC) or sodium deoxycholic acid (SDC), resulting in SC- or SDC-BNNS-OH dispersion with high up to 2 mg ml-1 and enhanced dispersion stability due to the increased negative zeta potential. While prepared SC-BNNS-OH revealed multi-layered BNNS structures, the large lateral sizes of hundreds nanometers and clear h-BN lattice structures are very promising for the preparation and application of water-processable BNNS-based nanomaterials. It is regarded that noncovalent functionalization of BNNS-OH based on σ-π interaction between with σ-rich bile acid-based amphiphiles and π-rich BNNS is very effective to formulate multi-functional BNNS-based nanomaterials or hybrids that can be utilized in various applications where both the pristine properties of BNNS and the extra functions are simultaneously required.

Decontamination of solid substrates using supercritical carbon dioxide - Application with trade hydro-carbonated surfactants

International Nuclear Information System (INIS)

Galy, J.; Fournel, B.; Sawada, K.; Lacroix-Desmazes, P.; Lagerge, S.; Persin, M.

2007-01-01

The phase behavior of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) tri-block copolymers (PEO-PPO-PEO Pluronics) in liquid and supercritical carbon dioxide has been studied by cloud point measurements. It shows that such trade hydro-carbonated surfactants are fairly soluble (0.1 wt.%) in carbon dioxide in relatively mild conditions of temperature and pressure (T ≤ 65 degrees C, P ≤ 30 MPa). An empirical model based on the molecular weight of the copolymer has been proposed to predict the pressure-temperature phase diagram for a series of Pluronics (10 wt.% of ethylene oxide). Furthermore, the water/CO 2 interfacial tension has been measured to investigate the interactions between water and the polar moieties of the surfactants (PEO blocks and hydroxyl end-groups) as well as the interactions between CO 2 and the 'CO 2 -philic' moiety of the surfactants (PPO block). An interfacial saturation concentration was evidenced and it was shown to depend on the temperature at a given pressure. The cloud point curves and interfacial tension data are fully consistent with a change in the affinity of the surfactant for CO 2 versus pressure and temperature. A correlation between CO 2 -philic characteristics and surface active properties of the copolymers is given. (authors)

Surfactant therapy for maternal blood aspiration: an unusual cause of neonatal respiratory distress syndrome.

Science.gov (United States)

Celik, Istemi Han; Demirel, Gamze; Canpolat, Fuat Emre; Erdeve, Omer; Dilmen, Ugur

2012-10-01

Surfactant replacement therapy is the main treatment of neonatal respiratory distress syndrome. However, surfactant therapy has been shown to be effective in the treatment of other diseases causing neonatal respiratory diseases such as pulmonary hemorrhage, meconium aspiration syndrome, pneumonia/sepsis, pulmonary edema or acute lung injury resulting a secondary surfactant deficiency (SSD). Rarely, as like as in the present patient, exogenous blood aspiration such as breast milk or formula aspiration may lead to SSD. Blood in alveolus leads to a significant biochemical and functional disturbance of the surfactant system and inhibits surfactant production. Here, the authors report a preterm infant of 33 wk gestational age with secondary surfactant deficiency due to maternal blood aspiration because of abruptio placentae. She was received two courses of beractant, a natural bovine surfactant, therapy in 24 h. She was extubated on second day and did not require oxygen on 4(th) day. To the authors' knowledge, this is the first reported case of SSD due to maternal blood aspiration treated with surfactant. In conditions such as abruptio placentae, infant should be protected from blood aspiration and if respiratory distress occurs, surfactant inhibition and need for surfactant administration should be considered.

MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

Directory of Open Access Journals (Sweden)

Pirog T. Р.

2014-02-01

Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

Formation and characterization of zein-propylene glycol alginate-surfactant ternary complexes: Effect of surfactant type.

Science.gov (United States)

Dai, Lei; Sun, Cuixia; Wei, Yang; Zhan, Xinyu; Mao, Like; Gao, Yanxiang

2018-08-30

In this study, zein, propylene glycol alginate (PGA) and surfactant ternary complexes were fabricated by antisolvent co-precipitation method. Two types of surfactants (rhamnolipid and lecithin) were applied to generate zein-PGA-rhamnolipid (Z-P-R) and zein-PGA-lecithin (Z-P-L) ternary complexes, respectively. Results showed that the surfactant types significantly affected the properties of ternary complexes. The formation of ternary complexes was mainly due to the non-covalent interactions such as hydrogen bonding, electrostatic interaction and hydrophobic interactions among zein, PGA and surfactants. Moreover, the thermal stability of ternary complexes was enhanced with increasing the levels of both surfactants. Notably, ternary complex dispersions exhibited better stability against pH from 2 to 8. Furthermore, a compact network structure was observed in Z-P-R ternary complex, while Z-P-L ternary complex remained the spherical structure. These findings would provide new insights into the development of novel delivery system and expand the options, when zein-based complexes were utilized under different environment conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of double-tailed surfactant architecture on the conformation, self-assembly, and processing in polypeptide-surfactant complexes.

Science.gov (United States)

Junnila, Susanna; Hanski, Sirkku; Oakley, Richard J; Nummelin, Sami; Ruokolainen, Janne; Faul, Charl F J; Ikkala, Olli

2009-10-12

This work describes the solid-state conformational and structural properties of self-assembled polypeptide-surfactant complexes with double-tailed surfactants. Poly(L-lysine) was complexed with three dialkyl esters of phosphoric acid (i.e., phosphodiester surfactants), where the surfactant tail branching and length was varied to tune the supramolecular architecture in a facile way. After complexation with the branched surfactant bis(2-ethylhexyl) phosphate in an aqueous solution, the polypeptide chains adopted an alpha-helical conformation. These rod-like helices self-assembled into cylindrical phases with the amorphous alkyl tails pointing outward. In complexes with dioctyl phosphate and didodecyl phosphate, which have two linear n-octyl or n-dodecyl tails, respectively, the polypeptide formed antiparallel beta-sheets separated by alkyl layers, resulting in well-ordered lamellar self-assemblies. By heating, it was possible to trigger a partial opening of the beta-sheets and disruption of the lamellar phase. After repeated heating/cooling, all of these complexes also showed a glass transition between 37 and 50 degrees C. Organic solvent treatment and plasticization by overstoichiometric amount of surfactant led to structure modification in poly(L-lysine)-dioctyl phosphate complexes, PLL(diC8)(x) (x = 1.0-3.0). Here, the alpha-helical PLL is surrounded by the surfactants and these bottle-brush-like chains self-assemble in a hexagonal cylindrical morphology. As x is increased, the materials are clearly plasticized and the degree of ordering is improved: The stiff alpha-helical backbones in a softened surfactant matrix give rise to thermotropic liquid-crystalline phases. The complexes were examined by Fourier transform infrared spectroscopy, small- and wide-angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry, polarized optical microscopy, and circular dichroism.

Coconut-based biosorbents for water treatment--a review of the recent literature.

Science.gov (United States)

Bhatnagar, Amit; Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

2010-10-15

Biosorption is an emerging technique for water treatment utilizing abundantly available biomaterials (especially agricultural wastes). Among several agricultural wastes studied as biosorbents for water treatment, coconut has been of great importance as various parts of this tree (e.g. coir, shell, etc.) have been extensively studied as biosorbents for the removal of diverse type of pollutants from water. Coconut-based agricultural wastes have gained wide attention as effective biosorbents due to low-cost and significant adsorption potential for the removal of various aquatic pollutants. In this review, an extensive list of coconut-based biosorbents from vast literature has been compiled and their adsorption capacities for various aquatic pollutants as available in the literature are presented. Available abundantly, high biosorption capacity, cost-effectiveness and renewability are the important factors making these materials as economical alternatives for water treatment and waste remediation. This paper presents a state of the art review of coconut-based biosorbents used for water pollution control, highlighting and discussing key advancement on the preparation of novel adsorbents utilizing coconut wastes, its major challenges together with the future prospective. It is evident from the literature survey that coconut-based biosorbents have shown good potential for the removal of various aquatic pollutants. However, still there is a need to find out the practical utility of such developed adsorbents on commercial scale, leading to the superior improvement of pollution control and environmental preservation. Copyright © 2010 Elsevier B.V. All rights reserved.

Chemotherapeutic treatment reduces circulating levels of surfactant protein-D in children with acute lymphoblastic leukemia

DEFF Research Database (Denmark)

Rathe, Mathias; Sorensen, Grith L; Skov Wehner, Peder

2017-01-01

with acute lymphoblastic leukemia (ALL). PROCEDURE: In a prospective study, 43 children receiving treatment for ALL were monitored for mucosal toxicity from diagnosis through the induction phase of treatment. Serial blood draws were taken to determine the levels of SP-D, interleukin-6 (IL-6), C......BACKGROUND: Surfactant protein D (SP-D) is a host defense molecule of the innate immune system that enhances pathogen clearance and modulates inflammatory responses. We hypothesized that circulating SP-D levels are associated with chemotherapy-induced mucositis and infectious morbidity in children...

Surfactants non-monotonically modify the onset of Faraday waves

Science.gov (United States)

Strickland, Stephen; Shearer, Michael; Daniels, Karen

2017-11-01

When a water-filled container is vertically vibrated, subharmonic Faraday waves emerge once the driving from the vibrations exceeds viscous dissipation. In the presence of an insoluble surfactant, a viscous boundary layer forms at the contaminated surface to balance the Marangoni and Boussinesq stresses. For linear gravity-capillary waves in an undriven fluid, the surfactant-induced boundary layer increases the amount of viscous dissipation. In our analysis and experiments, we consider whether similar effects occur for nonlinear Faraday (gravity-capillary) waves. Assuming a finite-depth, infinite-breadth, low-viscosity fluid, we derive an analytic expression for the onset acceleration up to second order in ɛ =√{ 1 / Re } . This expression allows us to include fluid depth and driving frequency as parameters, in addition to the Marangoni and Boussinesq numbers. For millimetric fluid depths and driving frequencies of 30 to 120 Hz, our analysis recovers prior numerical results and agrees with our measurements of NBD-PC surfactant on DI water. In both case, the onset acceleration increases non-monotonically as a function of Marangoni and Boussinesq numbers. For shallower systems, our model predicts that surfactants could decrease the onset acceleration. DMS-0968258.

Effect of Difference in Fatty Acid Chain Lengths of Medium- Chain Lipids on Lipid/Surfactant/Water Phase Diagrams and Drug Solubility

Directory of Open Access Journals (Sweden)

Hetal N. Prajapati

2011-09-01

Full Text Available Lipids consisting of medium chain fatty acids are commonly used in the development of lipid-based selfemulsifying and self-microemulsifying drug delivery systems. However, no systematic approach to selecting one lipid over another has been reported in the literature. In this study, propylene glycol (PG monoester (PG monocaprylate, Capmul PG-8® and PG diester (PG dicaprylocaprate, Captex 200P® of C8-fatty acids were compared with PG monoester (PG monolaurate, Capmul PG-12® and PG diester (PG dilaurate, Capmul PG-2L® of C12-fatty acids with respect to their phase diagrams, and especially for their ability to form microemulsions in the presence of a common surfactant, Cremophor EL®, and water. The solubility of two model drugs, danazol and probucol, in the lipids and lipid/surfactant mixtures were also compared. The effect of the chain length of medium-chain fatty acids (C8 versus C12 on the phase diagrams of the lipids was minimal. Both shorter and longer chain lipids formed essentially similar microemulsion and emulsion regions in the presence of Cremophor EL® and water, although the C12-fatty acid esters formed larger gel regions in the phase diagrams than the C8-fatty acid esters. When monoesters were mixed with their respective diesters at 1:1 ratios, larger microemulsion regions with lower lipid particle sizes were observed compared to those obtained with individual lipids alone. While the solubility of both danazol and probucol increased greatly in all lipids studied, compared to their aqueous solubility, the solubility in C12-fatty acid esters was found to be lower than in C8-fatty acid esters when the lipids were used alone. This difference in solubility due to the difference in fatty acid chain length, practically disappeared when the lipids were combined with the surfactant.

Environmental and Irradiation Effect on the Biosynthesis of Bio surfactant by Some Local Bacterial Isolates

International Nuclear Information System (INIS)

Ghoneimy, E.; Ahmed, S.; Desouki, S.; Rasmy, W.; El-Shahawy, M.

2010-01-01

Twenty eight bacterial isolates were isolated from The Suez Gulf sea water from the coast of the El-Nasr Petroleum Company on Suez Canal and formation water from overhead of an oil well in western desert of Egypt named (M68). Sixteen bacterial isolates were obtained from The Suez Gulf sea water. Twelve bacterial isolates were obtained from formation water (M68). The bacterial isolates were screened for bio surfactant production by using emulsification activity and haemolytic activity. The most potent two isolates N8 and S8 were selected according to three parameters; the ability of isolate to grow and produce surfactant on wide range of ph, temperature and salinity. The most promising bacterial isolates were subjected to different doses of gamma irradiation in a trial to improve their abilities for bio surfactant production which resulted in a passive effect on bio surfactant production

Theoretical vibrational sum-frequency generation spectroscopy of water near lipid and surfactant monolayer interfaces

Energy Technology Data Exchange (ETDEWEB)

Roy, S.; Gruenbaum, S. M.; Skinner, J. L. [Theoretical Chemistry Institute and Department of Chemistry, 1101 University Ave., University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2014-11-14

Understanding the structure of water near cell membranes is crucial for characterizing water-mediated events such as molecular transport. To obtain structural information of water near a membrane, it is useful to have a surface-selective technique that can probe only interfacial water molecules. One such technique is vibrational sum-frequency generation (VSFG) spectroscopy. As model systems for studying membrane headgroup/water interactions, in this paper we consider lipid and surfactant monolayers on water. We adopt a theoretical approach combining molecular dynamics simulations and phase-sensitive VSFG to investigate water structure near these interfaces. Our simulated spectra are in qualitative agreement with experiments and reveal orientational ordering of interfacial water molecules near cationic, anionic, and zwitterionic interfaces. OH bonds of water molecules point toward an anionic interface leading to a positive VSFG peak, whereas the water hydrogen atoms point away from a cationic interface leading to a negative VSFG peak. Coexistence of these two interfacial water species is observed near interfaces between water and mixtures of cationic and anionic lipids, as indicated by the presence of both negative and positive peaks in their VSFG spectra. In the case of a zwitterionic interface, OH orientation is toward the interface on the average, resulting in a positive VSFG peak.

REMOVAL OF ANIONIC SURFACTANTS FROM WASTEWATER BY MAGNETIC MINERAL SORBENTS

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Oksana Vladimirova Makarchuk

2016-07-01

Full Text Available The simplest and most effective method of removing low concentrations of anionic surfactants such as sodium dodecyl benzenesulfonate (SDBS and sodium lauryl sulfate (SLS is adsorption. Among adsorbents the natural clays are cheap and promising for these purposes. However, there are significant difficulties in removal of spent sorbent after the adsorption process. So, the creation of magnetic sorbents that can be effectively removed from water after sorption by magnetic separation will be a successful decision. The aim of this investigation is the creation of cheap and efficient magnetic sorbents based on natural clays and magnetite for anionic surfactant removal from wastewater. We have synthesized a series of magnetic sorbents from different natural clays with a content of magnetite from 2 to 10 wt%. The ability of magnetic sorbents to remove SDBS and SLS from aqueous solutions has been studied for different adsorbate concentrations by varying the amount of adsorbent, temperature and shaking time. Thermodynamic parameters were calculated from the slope and intercept of the linear plots of ln K against 1/T. Analysis of adsorption results obtained at different temperatures showed that the adsorption pattern on magnetic sorbents correspond to the Langmuir isotherm. It is shown that with increasing the content of magnetite in the magnetic sorbents improves not only their separation from water by magnetic separation, but adsorption capacity to SDBS and SLS. Thus, we obtained of cheap magnetic sorbents based on natural clays and magnetite by the easy way, which not only quickly separated from the solution by magnetic separation, but effectively remove anionic surfactants.

Micellization behaviour and thermodynamic parameters of 12-2-12 gemini surfactant in (water + organic solvent) mixtures

Energy Technology Data Exchange (ETDEWEB)

Batigoec, Cigdem [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey); Akbas, Halide, E-mail: hakbas34@yahoo.com [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey); Boz, Mesut [Department of Chemistry, Faculty of Sciences, Trakya University, 22030 Edirne (Turkey)

2011-09-15

Highlights: > The cmc and {alpha} values of surfactant increased with increasing solvent content and temperature. > The values of ({Delta}G{sub m}{sup 0}) are negative in all cases for the micelle formation becomes less favourable. > The values of negative enthalpy indicate importance of the London dispersion forces for the micellization. > The positive entropy is due to a contribution supplied from the solvent. - Abstract: The effect of organic solvents on micellization behaviour and thermodynamic parameters of a cationic gemini (dimeric) surfactant, C{sub 12}H{sub 25}(CH{sub 3}){sub 2}N{sup +}-(CH{sub 2}){sub 2}-N{sup +}(CH{sub 3}){sub 2}C{sub 12}H{sub 25}.2Br{sup -}, (12-2-12) was studied in aqueous solutions over the range of T = (293.15 to 323.15) K using the conductometric technique. Ethylene glycol (EG), dimethylsulfoxide (DMSO) and 1,4-dioxan (DO) were used as organic solvents with three different contents. The critical micelle concentration (cmc) and the degree of counter ion dissociation ({alpha}) of micelles in the water and in the (water + organic solvent) mixtures including 10%, 20%, and 30% solvent contents were determined. The standard Gibbs free energy ({Delta}G{sub m}{sup 0}), enthalpy ({Delta}H{sub m}{sup 0}) and entropy ({Delta}S{sub m}{sup 0}) of micellization were estimated from the temperature dependence of the cmc values. It was observed that the critical micelle concentration of the gemini surfactant and the degree of counter ion dissociation of the micelle increased as the volume percentage of organic solvent, and temperature increased. The standard Gibbs free energy of micellization was found to be less negative with the increase in the organic solvent content and temperature.

Surfactant-enhanced alkaline flooding for light oil recovery. Final report

Energy Technology Data Exchange (ETDEWEB)

Wasan, D.T.

1996-05-01

In this report, we present the results of our experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12. 0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, we have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are discussed.

Changes in lung volume and ventilation during surfactant treatment in ventilated preterm infants

NARCIS (Netherlands)

Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Veenendaal, Mariëtte B.; van Kaam, Anton H.

2011-01-01

The immediate and regional effects of exogenous surfactant in open lung high-frequency oscillatory ventilated (HFOV) preterm infants are unknown. To assess regional changes in lung volume, mechanics, and ventilation during and after surfactant administration in HFOV preterm infants with respiratory

Surfactant phosphatidylcholine metabolism and surfactant function in preterm, ventilated lambs

International Nuclear Information System (INIS)

Jobe, A.H.; Ikegami, M.; Seidner, S.R.; Pettenazzo, A.; Ruffini, L.

1989-01-01

Preterm lambs were delivered at 138 days gestational age and ventilated for periods up to 24 h in order to study surfactant metabolism and surfactant function. The surfactant-saturated phosphatidylcholine pool in the alveolar wash was 13 +/- 4 mumol/kg and did not change from 10 min to 24 h after birth. Trace amounts of labeled natural sheep surfactant were mixed with fetal lung fluid at birth. By 24 h, 80% of the label had become lung-tissue-associated, yet there was no loss of label from phosphatidylcholine in the lungs when calculated as the sum of the lung tissue plus alveolar wash. De novo synthesized phosphatidylcholine was labeled with choline given by intravascular injection at 1 h of age. Labeled phosphatidylcholine accumulated in the lung tissue linearly to 24 h, and the labeled phosphatidylcholine moved through lamellar body to alveolar pools. The turnover time for alveolar phosphatidylcholine was estimated to be about 13 h, indicating an active metabolic pool. A less surface-active surfactant fraction recovered as a supernatant after centrifugation of the alveolar washes at 40,000 x g increased from birth to 10 min of ventilation, but no subsequent changes in the distribution of surfactant phosphatidylcholine in surfactant fractions occurred. The results were consistent with recycling pathway(s) that maintained surface-active surfactant pools in preterm ventilated lambs

Maillard Conjugation of Sodium Alginate to Whey Protein for Enhanced Resistance to Surfactant-Induced Competitive Displacement from Air-Water Interfaces.

Science.gov (United States)

Cai, Bingqing; Saito, Anna; Ikeda, Shinya

2018-01-24

Whey protein adsorbed to an interface forms a viscoelastic interfacial film but is displaced competitively from the interface by a small-molecule surfactant added afterward. The present study evaluated the impact of the covalent conjugation of high- or low-molecular-weight sodium alginate (HA or LA) to whey protein isolate (WPI) via the Maillard reaction on the ability of whey protein to resist surfactant-induced competitive displacement from the air-water interface. Surfactant added after the pre-adsorption of conjugate to the interface increased surface pressure. At a given surface pressure, the WPI-LA conjugate showed a significantly higher interfacial area coverage and lower interfacial film thickness compared to those of the WPI-HA conjugate or unconjugated WPI. The addition of LA to the aqueous phase had little effect on the interfacial area and thickness of pre-adsorbed WPI. These results suggest the importance of the molecular weight of the polysaccharide moiety in determining interfacial properties of whey protein-alginate conjugates.

Study of the enhanced oil recovery with surfactant based systems; Estudo de recuperacao avancada de petroleo por sistemas a base de tensoativos

Energy Technology Data Exchange (ETDEWEB)

Ribeiro Neto, Valdir Cotrim; Paulino, Luisa Cimatti; Acyoly, Alessandra; Santos, Enio Rafael M.; Dantas Neto, Afonso Avelino [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2008-07-01

The recent changes in the world scenario, the large reserves of heavy oils and also the lack of new discoveries of large petroleum fields are indications that, in the near future, the oil recovery by conventional methods will be limited. In order to increase the efficiency of the extraction process, it must be used enhanced recovery methods. One of these technologies is the injection of surfactant solutions, where exists a chemical interaction between the injected fluid and the reservoir's fluid. With this in mind, this work was developed with two main objectives: to study of parameters that influence the surfactant behavior in solution, namely the critical micelle concentration (CMC), the surface and interface tensions between fluids and the evaluation of oil recovery with these solutions. After the Botucatu sandstone (Brazil) porosity study, the plug samples were submitted to assay steps comprising saturation with seawater and petroleum, conventional recovery with seawater and enhanced recovery with surfactant solutions. The solutions were studied in enhanced recovery step, when the plug samples could already be compared to a mature field. The PJN surfactant, at a concentration 1000% above CMC in water, had a higher recovery factor, causing the original oil in place to be recovered by an extra 20.97%, after conventional recovery with seawater. (author)

A novel viscoelastic surfactant suitable for use in high temperature carbonate reservoirs for diverted acidizing stimulation treatments

Energy Technology Data Exchange (ETDEWEB)

Holt, Stuart; Zhou, Jian; Gadberry, Fred [AkzoNobel Surface Chemistry, Forth Worth, TX (United States); Nasr-El-Din, Hisham; Wang, Guanqun [Texas A and M University, College Station, TX (United States). Dept. of Petroleum Engineering

2012-07-01

Due to the low permeability of many carbonate hydrocarbon-bearing reservoirs, it is difficult to achieve economic hydrocarbon recovery from a well without secondary stimulation. Bullheading of strong acids, such as HCl is practiced in low temperature reservoirs, but as the bottom hole temperature (BHT) rises, the acid becomes increasingly corrosive, causing facial dissolution and sub-optimal wormhole network development. In the last decade, viscoelastic surfactants (VES) have been added to HCl acid systems to improve the stimulation of HT carbonate reservoirs. The VES form 'living polymers' or worm-like micelles as electrolyte concentration rises in the acid due to reaction with the reservoir. This leads to viscosification of the stimulation fluid. The viscosification slows further acid reaction in the region already contacted by the acid, and forces the acid to take an alternate path into the rock, leading to diversion of the acids further down the well to the harder to access toe or lower permeability zones. Until recently, the maximum BHT that such VES-based diverting systems could be used was up to about 250 deg F/120 deg C. Above that temperature, all viscous properties of the fluid are lost, destroying the mechanism of acid diversion. A recently developed novel viscoelastic surfactant provides nearly 100 deg F/55 deg C extension in the BHT range in which diverted acid treatments can be used. These fluids are able to maintain both viscosity up to about 375 deg F/190 deg C, with the elastic modulus predominating up to 350 deg F/175 deg C. It is the elasticity which is particularly important in acid diversion. These fluids can have their viscosity readily broken by in-situ hydrocarbons, dilution with water or by using a mutual solvent. The broken fluids are readily removed from the near-well bore, leaving the newly created wormhole network to produce the target hydrocarbons. The new VES is significantly more environmentally benign compared with current

Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats.

Directory of Open Access Journals (Sweden)

Wolfram Burkhardt

Full Text Available PURPOSE: Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf and to test in surfactant depleted Wistar rats whether Persurf achieves I. a more homogenous pulmonary distribution and II. a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS: Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS: Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS: In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.

Facile synthesis of functionalized ionic surfactant templated mesoporous silica for incorporation of poorly water-soluble drug.

Science.gov (United States)

Li, Jing; Xu, Lu; Yang, Baixue; Wang, Hongyu; Bao, Zhihong; Pan, Weisan; Li, Sanming

2015-08-15

The present paper reported amino group functionalized anionic surfactant templated mesoporous silica (Amino-AMS) for loading and release of poorly water-soluble drug indomethacin (IMC) and carboxyl group functionalized cationic surfactant templated mesoporous silica (Carboxyl-CMS) for loading and release of poorly water-soluble drug famotidine (FMT). Herein, Amino-AMS and Carboxyl-CMS were facilely synthesized using co-condensation method through two types of silane coupling agent. Amino-AMS was spherical nanoparticles, and Carboxyl-CMS was well-formed spherical nanosphere with a thin layer presented at the edge. Drug loading capacity was obviously enhanced when using Amino-AMS and Carboxyl-CMS as drug carriers due to the stronger hydrogen bonding force formed between surface modified carrier and drug. Amino-AMS and Carboxyl-CMS had the ability to transform crystalline state of loaded drug from crystalline phase to amorphous phase. Therefore, IMC loaded Amino-AMS presented obviously faster release than IMC because amorphous phase of IMC favored its dissolution. The application of asymmetric membrane capsule delayed FMT release significantly, and Carboxyl-CMS favored sustained release of FMT due to its long mesoporous channels and strong interaction formed between its carboxyl group and amino group of FMT. Copyright © 2015 Elsevier B.V. All rights reserved.

Thermodynamic aspects of polymer–surfactant interactions: Gemini (16-5-16-PVP-water system

Directory of Open Access Journals (Sweden)

Naved Azum

2016-11-01

Full Text Available The interaction between polyvinylpyrrolidone (PVP and gemini surfactant (16-5-16 in aqueous solution has been analyzed using conductometry. From conductivity data the critical aggregation concentration (cac, critical micelle concentration (cmc, the effective degree of counter-ion binding (β at different temperatures were obtained. The thermodynamic parameters, i.e., Gibbs energy of aggregation and micellization, standard enthalpy of aggregation, and standard entropy of aggregation of surfactant/polymer system were estimated, employing pseudophase separation model. The negative values of Gibbs energy and standard enthalpy suggest that the surfactant/polymer aggregation process is spontaneous and exothermic respectively.

Novel sample preparation method for surfactant containing suppositories: effect of micelle formation on drug recovery.

Science.gov (United States)

Kalmár, Éva; Ueno, Konomi; Forgó, Péter; Szakonyi, Gerda; Dombi, György

2013-09-01

Rectal drug delivery is currently at the focus of attention. Surfactants promote drug release from the suppository bases and enhance the formulation properties. The aim of our work was to develop a sample preparation method for HPLC analysis for a suppository base containing 95% hard fat, 2.5% Tween 20 and 2.5% Tween 60. A conventional sample preparation method did not provide successful results as the recovery of the drug failed to fulfil the validation criterion 95-105%. This was caused by the non-ionic surfactants in the suppository base incorporating some of the drug, preventing its release. As guidance for the formulation from an analytical aspect, we suggest a well defined surfactant content based on the turbidimetric determination of the CMC (critical micelle formation concentration) in the applied methanol-water solvent. Our CMC data correlate well with the results of previous studies. As regards the sample preparation procedure, a study was performed of the effects of ionic strength and pH on the drug recovery with the avoidance of degradation of the drug during the procedure. Aminophenazone and paracetamol were used as model drugs. The optimum conditions for drug release from the molten suppository base were found to be 100 mM NaCl, 20-40 mM NaOH and a 30 min ultrasonic treatment of the final sample solution. As these conditions could cause the degradation of the drugs in the solution, this was followed by NMR spectroscopy, and the results indicated that degradation did not take place. The determined CMCs were 0.08 mM for Tween 20, 0.06 mM for Tween 60 and 0.04 mM for a combined Tween 20, Tween 60 system. Copyright © 2013 Elsevier B.V. All rights reserved.

Zeta potential study of Sb2S3 nanoparticles synthesized by a facile polyol method in various surfactants

Science.gov (United States)

Saxena, Monika; Okram, Gunadhor Singh

2018-05-01

In the present work, we report the successful synthesis of stibnite Sb2S3 nanoparticles (NPs) by a facile polyol method using various surfactant. The structural and optical properties were investigated by X-ray diffraction (XRD), Raman spectroscopy and Zeta potential. Rietveld refinement of XRD data confirms the single phase orthorhombic crystal structure of stibnite Sb2S3. Presence of six obvious Raman modes further confirmed their stoichiometric formation. Effect of different surfactants on the surface charge of Sb2S3 NPs was studied using Zeta potential measurement in deionized water at different pH values. They reveal that these NPs are more stable when it was synthesized in presence of EDTA than that of CTAB or without surfactant samples with high zeta potential. The isoelectronic point was found at pH = 6.4 for pure sample, 3.5 and 7.2 for CTAB and not found for EDTA Sb2S3 samples. This information can be useful for many industrial applications like pharmaceuticals, ceramics, waste water treatment and medicines.

The effect of pressure on the phase behavior of surfactant systems: An experimental study

DEFF Research Database (Denmark)

Sandersen, Sara Bülow; Stenby, Erling Halfdan; von Solms, Nicolas

2012-01-01

Enhanced oil recovery is employed in many mature oil reservoirs to maintain or increase the reservoir recovery factor. In this context, surfactant flooding has recently gained interest again. Surfactant flooding is the injection of surfactants (and co-surfactants) into the reservoir, in order...... to create microemulsions at the interface between crude oil and water, thus obtaining very low interfacial tension, which consequently helps mobilize the trapped oil.In this work a surfactant system, which has been thoroughly described at atmospheric pressure, is examined at elevated pressure. The effect...

Phase transitions in surfactant monolayers

International Nuclear Information System (INIS)

Casson, B.D.

1998-01-01

Two-dimensional phase transitions have been studied in surfactant monolayers at the air/water interface by sum-frequency spectroscopy and ellipsometry. In equilibrium monolayers of medium-chain alcohols C n H 2n+1 OH (n = 9-14) a transition from a two-dimensional crystalline phase to a liquid was observed at temperatures above the bulk melting point. The small population of gauche defects in the solid phase increased only slightly at the phase transition. A model of the hydrocarbon chains as freely rotating rigid rods allowed the area per molecule and chain tilt in the liquid phase to be determined. The area per molecule, chain tilt and density of the liquid phase all increased with increasing chain length, but for each chain length the density was higher than in a bulk liquid hydrocarbon. In a monolayer of decanol adsorbed at the air/water interface a transition from a two-dimensional liquid to a gas was observed. A clear discontinuity in the coefficient of ellipticity as a function of temperature showed that the transition is first-order. This result suggests that liquid-gas phase transitions in surfactant monolayers may be more widespread than once thought. A solid-liquid phase transition has also been studied in mixed monolayers of dodecanol with an anionic surfactant (sodium dodecyl sulphate) and with a homologous series of cationic surfactants (alkyltrimethylammonium bromides: C n TABs, n = 12, 14, 16). The composition and structure of the mixed monolayers was studied above and below the phase transition. At low temperatures the mixed monolayers were as densely packed as a monolayer of pure dodecanol in its solid phase. At a fixed temperature the monolayers under-went a first-order phase transition to form a phase that was less dense and more conformationally disordered. The proportion of ionic surfactant in the mixed monolayer was greatest in the high temperature phase. As the chain length of the C n TAB increased the number of conformational defects

Acidic Pretreatment of Wheat Straw in Decanol for the Production of Surfactant, Lignin and Glucose

Directory of Open Access Journals (Sweden)

Boris Estrine

2011-12-01

Full Text Available Wheat straw is an abundant residue of agriculture which is increasingly being considered as feedstock for the production of fuels, energy and chemicals. The acidic decanol-based pre-treatment of wheat straw has been investigated in this work. Wheat straw hemicellulose has been efficiently converted during a single step operation into decyl pentoside surfactants and the remaining material has been preserved keeping all its promises as potential feedstock for fuels or value added platform chemicals such as hydroxymethylfurfural (HMF. The enzymatic digestibility of the cellulose contained in the straw residue has been evaluated and the lignin prepared from the material characterized. Wheat-based surfactants thus obtained have exhibited superior surface properties compared to fossil-based polyethoxylates decyl alcohol or alkyl oligoglucosides, some of which are largely used surfactants. In view of the growing importance of renewable resource-based molecules in the chemical industry, this approach may open a new avenue for the conversion of wheat straw into various chemicals.

PDMS-modified poly(styrene-alt-maleic anhydride)s as water-borne coatings based on surfactant-free latexes

NARCIS (Netherlands)

Gunbas, I.D.; Wouters, M.E.L.; Benthem, R.A.T.M. van; Koning, C.E.; Noordover, B.A.J.

2013-01-01

In this work, two series of PDMS-modified poly(styrene-alt-maleic anhydride)s (PSMA) were prepared by the partial imidization of their anhydride groups with mono-functional, amine-terminated polydimethyl siloxanes (PDMS-NH2) with two different molecular weights. Subsequently, surfactant-free

Influence of Surfactants and Fluoride against Enamel Erosion.

Science.gov (United States)

Zanatta, Rayssa Ferreira; Ávila, Daniele Mara da Silva; Miyamoto, Karen Mayumi; Torres, Carlos Rocha Gomes; Borges, Alessandra Bühler

2018-06-06

This study investigated the effect of surfactants associated with sodium fluoride (NaF) on enamel erosion prevention, using an erosion-remineralization in vitro model. Sodium lauryl sulfate (SLS), polysorbate 20 (P20), and cocoamidopropyl betaine (CAPB) were tested, at concentrations of 1.0 and 1.5%, and associated or not with NaF (275 ppm). The control groups were distilled water and the NaF solution. Bovine enamel samples (n = 12) were prepared and submitted to a 5-day cycling model: acid challenge (0.3% citric acid, pH 2.6, 4×/day), human saliva (2 h, 4×/day), and the treatment solutions (2 min, 2×/day). The protective potential of the agents against initial erosion was assessed by microhardness and the surface loss by profilometry. Enamel surface wettability was determined by goniometry, protein adsorption was measured by spectroscopy (FTIR), and the KOH-soluble fluoride was quantified. Goniometry showed that SLS and CAPB increased enamel wettability. No differences were found among the surfactants regarding protein adsorption. Microhardness showed that SLS reduced NaF protection. P20 (1 and 1.5%) and CAPB 1.5% presented a protective effect, but lower than the NaF solution. Profilometry showed that CAPB protected enamel, but no agent associated with NaF promoted a higher protection than the NaF solution alone. KOH-soluble fluoride analysis showed that all surfactants reduced the fluoride adsorption on the enamel surface. Therefore, the surfactants tested (except for P20) changed the enamel surface energy. The SLS decreased the protective potential of NaF on initial erosion, but no tested agent interfered with the protective effect of NaF on enamel erosive wear. © 2018 S. Karger AG, Basel.

Potential of Nanotechnology based water treatment solutions for the improvement of drinking water supplies in developing countries

Science.gov (United States)

Dutta, Joydeep; Bhattacharya, Prosun; Bundschuh, Jochen

2016-04-01

Over the last decades explosive population growth in the world has led to water scarcity across the globe putting additional pressure already scarce ground water resources and is pushing scientists and researchers to come up with new alternatives to monitor and treat water for use by mankind and for food security. Nearly 4 billion people around the world are known to lack access to clean water supply. Systematic water quality data is important for the assessment of health risks as well as for developing appropriate and affordable technologies for waste and drinking water treatments, and long-term decision making policy against water quality management. Traditional water treatment technologies are generally chemical-intensive processes requiring extremely large infrastructural support thus limiting their effective applications in developing nations which creates an artificial barrier to the application of technological solutions for the provision of clean water. Nanotechnology-based systems are in retrospect, smaller, energy and resource efficient. Economic impact assessment of the implementation of nanotechnology in water treatment and studies on cost-effectiveness and environmental and social impacts is of key importance prior to its wide spread acceptance. Government agencies and inter-governmental bodies driving research and development activities need to measure the effective potential of nanotechnology as a solution to global water challenges in order to effectively engage in fiscal, economic and social issues at national and international levels for different types of source waters with new national and international initiatives on nanotechnology and water need to be launched. Environmental pollution and industrialization in global scale is further leading to pollution of available water sources and thus hygienically friendly purification technologies are the need of the hour. Thus cost-effective treatment of pollutants for the transformation of hazardous

Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

Science.gov (United States)

Misra, R. K.; Patel, J. H.; Baxi, V. R.

2010-05-01

SummaryGreywater is considered as a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from reuse of greywater which may affect agricultural productivity and environmental sustainability adversely. We conducted a glasshouse experiment to examine variation in growth, water and nutrient use of tomato ( Lycopersicon esculentum Mill. cv. Grosse Lisse) using tap water (TW), laundry greywater (GW) and solutions of low and high concentration of a detergent surfactant (LC and HC, respectively) as irrigation treatments. Each treatment was replicated five times using a randomised block design. Measurements throughout the experiment showed greywater to be significantly more alkaline and saline than the other types of irrigation water. Although all plants received 16 irrigations over a period of 9 weeks until flowering, there were little or no significant effects of irrigation treatments on plant growth. Soil water retention following irrigation reduced significantly when plants were irrigated with GW or surfactant solutions on only three of 12 occasions. On one occasion, water use measured as evapotranspiration (ET) with GW irrigation was similar to TW, but it was significantly higher than the plants receiving HC irrigation. At harvest, various components of plant biomass and leaf area for GW irrigated plants were found to be similar or significantly higher than the TW irrigated plants with a common trend of GW ⩾ TW > LC ⩾ HC. Whole-plant concentration was measured for 12 essential plant nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn, Mo and B) and Na (often considered as a beneficial nutrient). Irrigation treatments affected the concentration of four nutrients (P, Fe, Zn and Na) and uptake of seven nutrients (P, K, Ca, Mg, Na, Fe and B) significantly. Uptake of these seven nutrients by tomato was generally in the order GW ⩾ TW > HC ⩾ LC. GW

Fabrication and Water Treatment Application of Carbon Nanotubes (CNTs)-Based Composite Membranes: A Review.

Science.gov (United States)

Ma, Lining; Dong, Xinfa; Chen, Mingliang; Zhu, Li; Wang, Chaoxian; Yang, Fenglin; Dong, Yingchao

2017-03-18

Membrane separation technology is widely explored for various applications, such as water desalination and wastewater treatment, which can alleviate the global issue of fresh water scarcity. Specifically, carbon nanotubes (CNTs)-based composite membranes are increasingly of interest due to the combined merits of CNTs and membrane separation, offering enhanced membrane properties. This article first briefly discusses fabrication and growth mechanisms, characterization and functionalization techniques of CNTs, and then reviews the fabrication methods for CNTs-based composite membranes in detail. The applications of CNTs-based composite membranes in water treatment are comprehensively reviewed, including seawater or brine desalination, oil-water separation, removal of heavy metal ions and emerging pollutants as well as membrane separation coupled with assistant techniques. Furthermore, the future direction and perspective for CNTs-based composite membranes are also briefly outlined.

Fabrication and Water Treatment Application of Carbon Nanotubes (CNTs-Based Composite Membranes: A Review

Directory of Open Access Journals (Sweden)

Lining Ma

2017-03-01

Full Text Available Membrane separation technology is widely explored for various applications, such as water desalination and wastewater treatment, which can alleviate the global issue of fresh water scarcity. Specifically, carbon nanotubes (CNTs-based composite membranes are increasingly of interest due to the combined merits of CNTs and membrane separation, offering enhanced membrane properties. This article first briefly discusses fabrication and growth mechanisms, characterization and functionalization techniques of CNTs, and then reviews the fabrication methods for CNTs-based composite membranes in detail. The applications of CNTs-based composite membranes in water treatment are comprehensively reviewed, including seawater or brine desalination, oil-water separation, removal of heavy metal ions and emerging pollutants as well as membrane separation coupled with assistant techniques. Furthermore, the future direction and perspective for CNTs-based composite membranes are also briefly outlined.

Towards anti-corrosion coatings from surfactant-free latexes based on maleic anhydride containing polymers

NARCIS (Netherlands)

Soer, W.J.; Ming, W.; Koning, C.E.; Benthem, van R.A.T.M.

2008-01-01

We report on the film formation of surfactant-free, artificial latexes based on copolymers containing maleic anhydride. Different metallic substrates, such as aluminum, steel and magnesium alloys, were coated with three different latexes. A commercial polyester based coating was used as a

The Initial Comparison Study of Sodium Lignosulfonate, Sodium Dodecyl Benzene Sulfonate, and Sodium p-Toluene Sulfonate Surfactant for Enhanced Oil Recovery

Science.gov (United States)

Khoirul Anas, Argo; Iman Prakoso, Nurcahyo; Sasvita, Dilla

2018-04-01

Surfactant (surface active agent) exhibit numerous interesting properties that enable their use as additional component in mobilising of residual oil from capillary pore after secondary recovery process using gas injection and water flooding. In this study, Sodium Lignosulfonate (SLS) surfactant was successfully synthesized by applying batch method using lignin from oil palm empty fruit bunches as precursor. Furthermore, its performance in reducing interfacial tension of crude oil and formation water colloidal system was compared with commercial available surfactant including Sodium Dodecyl Benzene Sulfonate (SDBS) and Sodium p-Toluene Sulfonate (SpTS). The synthesized SLS surfactant was characterized by using Fourier Transform Infrared (FTIR) spectroscopy. Meanwhile, its performance in reducing interfacial tension of crude oil and formation water colloidal system was analyzed by using compatibility test, phase behaviour analysis, and interfacial tension (IFT) measurement. The compatibility test shows that SLS, SDBS, and SpTS surfactants were compatible with formation water. In addition, the phase behaviour analysis shows that SLS surfactant was better than SpTS surfactant, while SDBS surfactant generates the highest performance proved by the best microemulsion formation resulted by SDBS. Furthermore, the optimum concentration of SLS, SDBS, and SpTS surfactants in reducing the interfacial tension of crude oil and formation water was 1.0%. The IFT measurement indicates that the performance of SLS with the value of 1.67 mN/m was also better than SpTS surfactant with the value of 3.59 mN/m. Meanwhile, SDBS surfactant shows the best performance with the IFT value of 0.47 mN/m.

Evaluation of acute and chronic toxicity of DSS and LAS surfactants undergoing the irradiation with electron beam

International Nuclear Information System (INIS)

Romanelli, Maria Fernanda

2004-01-01

Surfactants are synthetic organic compounds widely used in cosmetic, food, textile, dyers and paper production industries and in particular detergents and others cleaning products industries. The world consumption is nearly 8 million tons per year. One of the main environmental issues coming from the use of these compounds is their toxicity that compromises the biological treatment of effluents and the quality of receiving waters. The objective of this work was the application of ionizing radiation by electron beam in the degradation and reduction of acute and chronic toxicities of surfactants sodium dodecylsulfate (SDS), dodecyl p-benzenesulfonate acid (LAS) and sodium dodecyl p-benzenesulfonate (LAS). This treatment technology has been studied as a pre-treatment for effluents containing toxic and non-biodegradable compounds, before the biological treatment. Two acute toxicity assays were employed, one with the micro-crustacean Daphnia similis and the other with the luminescent bacterium Vibrio fischeri along with a chronic toxicity assay with the micro-crustacean Ceriodaphnia dubia (just for SDS and acid LAS) for the non-irradiated and irradiated samples and radiation doses 3.0 kGy, 6.0 kGy, 9.0 kGy and 12.0 kGy. Physical-chemical parameters were evaluated for the following up the degradation of the surfactant molecules. The reductions of acute toxicity varied between 72.49% and 90.98% for SDS, 18.22% and 78.98% for acid LAS and 82.66% and 94.26% for sodium LAS. For the chronic toxicity, the reduction percentages varied between 64.03% and 83.01% for SDS and 47.48% and 64.91% for acid LAS. When one considers the application of the electron beam as a pre-treatment of effluents containing high concentrations of surfactants, the toxicity is an essential parameter allowing the further biological treatment of these effluents. (author)

The toxicity of cationic surfactant HDTMA-Br, desorbed from surfactant modified zeolite, towards faecal indicator and environmental microorganisms.

Science.gov (United States)

Reeve, Peter J; Fallowfield, Howard J

2017-10-05

Surfactant Modified Zeolite (SMZ) represents a versatile, cost-effective permeable reactive material, capable of treating multiple classes of contaminants. The potential for HDTMA-Br, a cationic surfactant commonly used to modify zeolite, to desorb from the zeolite surface has been identified as a potential issue for the ongoing use of SMZ in water remediation contexts. This paper investigates the toxicity of HDTMA-Br towards enteric virus surrogates, F-RNA bacteriophage MS2 and E. coli, Bacillus subtilis, and soil microflora. The concentration of surfactant desorbing from SMZ was quantified through a bioassay using E. coli. Results showed HDTMA-Br concentrations of ≥10 -5 M were toxic to MS2, ≥10 -4 M were toxic to E. coli and ≥10 -6 M were toxic to B. subtilis. No toxic relationship was established between HDTMA-Br and soil microflora. Desorption of ≥10 -4 M of HDTMA-Br was shown for the two SMZ samples under the mixing conditions used. Effects of this surfactant on total soil microflora were ambiguous since no toxic relationship could be established, however, HDTMA-Br, at concentrations desorbing from SMZ, were shown to impact the soil bacterium B. subtilis. Further research is required to determine the effect of this surfactant on microbial populations and species diversity in soils. Copyright © 2017 Elsevier B.V. All rights reserved.

Gemini surfactant for fluorescent and stable quantum dots in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Li Haibing [Key Laboratory of Pesticide and Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Wang Xiaoqiong [Key Laboratory of Pesticide and Chemical Biology (CCNU), Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079 (China); Gao Zhinong [Department of Chemistry, Wuhan University, Wuhan 430072 (China); He Zhike [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

2007-05-23

Highly fluorescent and stable CdSe/ZnS core/shell quantum dots (QDs) coated with gemini surfactant are successfully synthesized in aqueous media. Analyses of luminescence spectrometry, ultraviolet-visible (UV-vis) spectrophotometry, and transmission electron micrographs (TEMs) indicate that the water-soluble QDs are monodisperse and have a luminescence enhancement compared with the original hydrophobic QDs. The water-soluble QDs coated with gemini surfactant are shown to be biocompatible, photostable, and have been proven to be suitable for live cell imaging.

Gemini surfactant for fluorescent and stable quantum dots in aqueous solution

International Nuclear Information System (INIS)

Li Haibing; Wang Xiaoqiong; Gao Zhinong; He Zhike

2007-01-01

Highly fluorescent and stable CdSe/ZnS core/shell quantum dots (QDs) coated with gemini surfactant are successfully synthesized in aqueous media. Analyses of luminescence spectrometry, ultraviolet-visible (UV-vis) spectrophotometry, and transmission electron micrographs (TEMs) indicate that the water-soluble QDs are monodisperse and have a luminescence enhancement compared with the original hydrophobic QDs. The water-soluble QDs coated with gemini surfactant are shown to be biocompatible, photostable, and have been proven to be suitable for live cell imaging

Solar based water treatment technologies

International Nuclear Information System (INIS)

Ahmad, I.; Hyder, M.J.

2000-01-01

In developing countries, the quality of drinking water is so poor that reports of 80% diseases from water-related causes is no surprise (Tebbet, 90). Frequently, there are reports in press of outbreak of epidemics in cities due to the unhygienic drinking-water. The state of affairs in the rural areas can be well imagined, where majority of the people live with no piped water. This paper describes the solar-based methods of removing organic pollutants from waste-water (also called Advanced Oxidation Technologies) and solar desalination. Experimental results of a simple solar water-sterilization technique have been discussed, along with suggestions to enhance the performance of this technique. (author)

Adsorption energies of poly(ethylene oxide)-based surfactants and nanoparticles on an air-water surface.

Science.gov (United States)

Zell, Zachary A; Isa, Lucio; Ilg, Patrick; Leal, L Gary; Squires, Todd M

2014-01-14

The self-assembly of polymer-based surfactants and nanoparticles on fluid-fluid interfaces is central to many applications, including dispersion stabilization, creation of novel 2D materials, and surface patterning. Very often these processes involve compressing interfacial monolayers of particles or polymers to obtain a desired material microstructure. At high surface pressures, however, even highly interfacially active objects can desorb from the interface. Methods of directly measuring the energy which keeps the polymer or particles bound to the interface (adsorption/desorption energies) are therefore of high interest for these processes. Moreover, though a geometric description linking adsorption energy and wetting properties through the definition of a contact angle can be established for rigid nano- or microparticles, such a description breaks down for deformable or aggregating objects. Here, we demonstrate a technique to quantify desorption energies directly, by comparing surface pressure-density compression measurements using a Wilhelmy plate and a custom-microfabricated deflection tensiometer. We focus on poly(ethylene oxide)-based polymers and nanoparticles. For PEO-based homo- and copolymers, the adsorption energy of PEO chains scales linearly with molecular weight and can be tuned by changing the subphase composition. Moreover, the desorption surface pressure of PEO-stabilized nanoparticles corresponds to the saturation surface pressure for spontaneously adsorbed monolayers, yielding trapping energies of ∼10(3) k(B)T.

Ionothermal synthesis of hierarchical BiOBr microspheres for water treatment

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dieqing [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, 100 Guilin Road, Shanghai 200231 (China); Department of Chemistry and Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Wen, Meicheng; Jiang, Bo; Li, Guisheng [The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, 100 Guilin Road, Shanghai 200231 (China); Yu, Jimmy C., E-mail: jimyu@cuhk.edu.hk [Department of Chemistry and Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China)

2012-04-15

Graphical abstract: Hierarchical BiOBr microspheres were prepared from a bromine-containing ionic liquid. The material was found effective for removing heavy metals, degrading organic pollutants and killing bacteria. Highlight: Black-Right-Pointing-Pointer Ionothermal synthesis of BiOBr microspheres with hierarchical structure. Black-Right-Pointing-Pointer Efficient mass transfer and excellent light-harvesting ability. Black-Right-Pointing-Pointer Suitable for removing heavy metals and treatment of organic dyes. Black-Right-Pointing-Pointer Remarkable photocatalytic bactericidal property. - Abstract: Bismuth oxybromide (BiOBr) micropsheres with hierarchical morphologies have been fabricated via an ionothermal synthesis route. Ionic liquid acts as a unique soft material capable of promoting nucleation and in situ growth of 3D hierarchical BiOBr mesocrystals without the help of surfactants. The as-prepared BiOBr nanomaterials can effectively remove heavy metal ions and organic dyes from wastewater. They can also kill Micrococcus lylae, a Gram positive bacterium, in water under fluorescent light irradiation. Their high adaptability in water treatment may be ascribed to their hierarchical structure, allowing them high surface to volume ratio, facile species transportation and excellent light-harvesting ability.

Ionothermal synthesis of hierarchical BiOBr microspheres for water treatment

International Nuclear Information System (INIS)

Zhang, Dieqing; Wen, Meicheng; Jiang, Bo; Li, Guisheng; Yu, Jimmy C.

2012-01-01

Graphical abstract: Hierarchical BiOBr microspheres were prepared from a bromine-containing ionic liquid. The material was found effective for removing heavy metals, degrading organic pollutants and killing bacteria. Highlight: ► Ionothermal synthesis of BiOBr microspheres with hierarchical structure. ► Efficient mass transfer and excellent light-harvesting ability. ► Suitable for removing heavy metals and treatment of organic dyes. ► Remarkable photocatalytic bactericidal property. - Abstract: Bismuth oxybromide (BiOBr) micropsheres with hierarchical morphologies have been fabricated via an ionothermal synthesis route. Ionic liquid acts as a unique soft material capable of promoting nucleation and in situ growth of 3D hierarchical BiOBr mesocrystals without the help of surfactants. The as-prepared BiOBr nanomaterials can effectively remove heavy metal ions and organic dyes from wastewater. They can also kill Micrococcus lylae, a Gram positive bacterium, in water under fluorescent light irradiation. Their high adaptability in water treatment may be ascribed to their hierarchical structure, allowing them high surface to volume ratio, facile species transportation and excellent light-harvesting ability.

Selective retardation of perfume oil evaporation from oil-in-water emulsions stabilized by either surfactant or nanoparticles.

Science.gov (United States)

Binks, Bernard P; Fletcher, Paul D I; Holt, Benjamin L; Beaussoubre, Pascal; Wong, Kenneth

2010-12-07

We have used dynamic headspace analysis to investigate the evaporation rates of perfume oils from stirred oil-in-water emulsions into a flowing gas stream. We compare the behavior of an oil of low water solubility (limonene) and one of high water solubility (benzyl acetate). It is shown how the evaporation of an oil of low water solubility is selectively retarded and how the retardation effect depends on the oil volume fraction in the emulsion. We compare how the evaporation retardation depends on the nature of the adsorbed film stabilizing the emulsion. Surfactant films are less effective than adsorbed films of nanoparticles, and the retardation can be further enhanced by compression of the adsorbed nanoparticle films by preshrinking the emulsion drops.

Cloud point extraction of copper, lead, cadmium, and iron using 2,6-diamino-4-phenyl-1,3,5-triazine and nonionic surfactant, and their flame atomic absorption spectrometric determination in water and canned food samples.

Science.gov (United States)

Citak, Demirhan; Tuzen, Mustafa

2012-01-01

A cloud point extraction procedure was optimized for the separation and preconcentration of lead(II), cadmium(II), copper(II), and iron(III) ions in various water and canned food samples. The metal ions formed complexes with 2,6-diamino-4-phenyl-1,3,5-triazine that were extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by flame atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, surfactant concentration, temperature, and incubation time, were optimized. LOD values based on three times the SD of the blank (3Sb) were 0.38, 0.48, 1.33, and 1.85 microg/L for cadmium(II), copper(II), lead(II), and iron(III) ions, respectively. The precision (RSD) of the method was in the 1.86-3.06% range (n=7). Validation of the procedure was carried out by analysis of National Institute of Standards and Technology Standard Reference Material (NIST-SRM) 1568a Rice Flour and GBW 07605 Tea. The method was applied to water and canned food samples for determination of metal ions.

Influence of metacide - surfactant complexes on agricultural crops

Directory of Open Access Journals (Sweden)

Orynkul Esimova

2014-12-01

Full Text Available The complexes based on surfactants and polyhexamethyleneguanidine hydrochloride (metacide are important for agriculture. This paper considers compositions of known bactericidal metacide with different surfactants: anionic surfactant sodium dodecylsulphate (DDSNa and nonionic surfactant Tween 80 (monooleate of oxyethylenated anhydrosorbitols. The effect of individual components and associates of metacide and surfactants on productivity and infection of cereals was studied. According to the study, the highest productivity and infection rate were shown by the associate of metacide and Tween-80. At concentration of Tween-80 in aqueous solution equal to 0.001% in combination with metacide, efficiency was 98% at 0% infection. The surface tension and the wetting of metacide, DDSNa, Tween-80, and associates of metacide with surfactants were studied. In comparison with individual components, metacide-DDSNa and metacide-Tween-80 associates have higher surface activity.

Catalytic Enzyme-Based Methods for Water Treatment and Water Distribution System Decontamination. 1. Literature Survey

Science.gov (United States)

2006-06-01

best examples of this is glucose isomerase, which has been used in the commercial production of high fructose corn syrup (HFCS) since 1967.230 Most...EDGEWOOD CHEMICAL BIOLOGICAL CENTER U.S. ARMY RESEARCH, DEVELOPMENT AND ENGINEERING COMMAND ECBC-TR-489 CATALYTIC ENZYME-BASED METHODS FOR WATER ...TREATMENT AND WATER DISTRIBUTION SYSTEM DECONTAMINATION 1. LITERATURE SURVEY Joseph J. DeFrank RESEARCH AND TECHNOLOGY DIRECTORATE June 2006 Approved for

Characterization of sodium bentonites: effect of treatment with ammonium salt- free organic surfactant; Caracterizacao de bentonitas sodicas: efeito do tratamento com surfactante organico livre de sal de amonio

Energy Technology Data Exchange (ETDEWEB)

Morita, R. Y.; Barbosa, R. V.; Kloss, J.R., E-mail: julianaweber@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Dartamento de Quimica e Biologia

2015-07-15

Bentonite, which the main clay mineral is montmorillonite, are commercially attractive because of its abundance in nature. The clays can be modified by ion exchange reactions of ions contained in the interlayer region with cationic surfactants that include ammonium or phosphonium salts. The clays origin and the type of surfactants (modifiers) are the main factors in the alteration of physical and chemical properties of these materials. This study aims to characterize and compare the results of natural bentonite commercially available and the effect of treatments with quaternary ammonium salt and an organic compound free of ammonium salt. The FTIR and XRD results indicate the process of organophilization of clays after treatment with the surfactants. These treatments have altered the average particle size, suggesting the formation of agglomerates, which was showed in the SEM images. The results of surface area and particle size data indicated the presence of larger particles. Although the two surfactants have shown similarities in the investigated properties, the organoclays free of ammonium salt are more promising in terms of its use as well as for their preparation and solubility. (author)

The use of isothermal titration calorimetry to assess the solubility enhancement of simvastatin by a range of surfactants

International Nuclear Information System (INIS)

Patel, Rajesh; Buckton, Graham; Gaisford, Simon

2007-01-01

Surfactants are commonly used to increase the solubility of poorly water soluble drugs but the interactions between drug and surfactant can be complex and quantitative relationships can be hard to derive. One approach is to quantify the thermodynamics of interaction and relate these parameters to known solubility or dissolution rate enhancement data. Isothermal titration calorimetry (ITC) was used to measure the enthalpy and free energy of transfer of a model drug (simvastatin) to a number of surfactant (SDS, HTAB, SDCH and Brij 35) micelles. These data were then compared with the solubility enhancements determined for each surfactant using HPLC assays. As expected, there was correlation between the free energy of transfer for the drug to each surfactant and the solubility enhancement of that surfactant. Although the data set is limited, the results suggest that ITC screening of a range of surfactants against a poorly water soluble drug may allow the selection of the best potential solubilising surfactants

Selection of surfactants for using in invert emulsion based on vegetable oil; Selecao de surfactantes para uso em emulsoes inversas a base de oleo vegetal

Energy Technology Data Exchange (ETDEWEB)

Silva, Giliane V.; Lacerda, Vanessa M.; Garcia, Rosangela B.; Costa, Marta [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Lab. de Pesquisa em Petroleo (LAPET); Girao, Joaquim Helder S. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

The purpose of this study was to investigate the superficial properties of a vegetable oil of degree nutritious front the several biodegradable surfactants, seeking to stabilize emulsions of the type water-in-oil, presents in formulations of fluids of perforation of oleofilic base. Mentioned them fluids they are suitable to the perforation of located oil wells in leases of high environmental sensibility and with inferior temperature to 250 deg F. The use of a fluid of that nature can make possible the discard of the solids perforated directly in the sea, sparing the application of previous treatments, or the transport of the same ones for dike-mother, operations that you/they can elevate the total cost of the perforation. The values of the superficial tension and of the concentration critical micellar, they were measured in the solutions oil vegetal/tensoactive, through the method of the ring (DuNouy), using a tensiometer DCA 315 (Thermo Cahn). The effects of the variation of the concentration and of the temperature in the superficial properties of the oil were certain. (author)

Improved methylene blue two-phase titration method for determining cationic surfactant concentration in high-salinity brine.

Science.gov (United States)

Cui, Leyu; Puerto, Maura; López-Salinas, José L; Biswal, Sibani L; Hirasaki, George J

2014-11-18

The methylene blue (MB) two-phase titration method is a rapid and efficient method for determining the concentrations of anionic surfactants. The point at which the aqueous and chloroform phases appear equally blue is called Epton's end point. However, many inorganic anions, e.g., Cl(-), NO3(-), Br(-), and I(-), can form ion pairs with MB(+) and interfere with Epton's end point, resulting in the failure of the MB two-phase titration in high-salinity brine. Here we present a method to extend the MB two-phase titration method for determining the concentration of various cationic surfactants in both deionized water and high-salinity brine (22% total dissolved solid). A colorless end point, at which the blue color is completely transferred from the aqueous phase to the chloroform phase, is proposed as titration end point. Light absorbance at the characteristic wavelength of MB is measured using a spectrophotometer. When the absorbance falls below a threshold value of 0.04, the aqueous phase is considered colorless, indicating that the end point has been reached. By using this improved method, the overall error for the titration of a permanent cationic surfactant, e.g., dodecyltrimethylammonium bromide, in deionized (DI) water and high-salinity brine is 1.274% and 1.322% with limits of detection (LOD) of 0.149 and 0.215 mM, respectively. Compared to the traditional acid-base titration method, the error of this improved method for a switchable cationic surfactant, e.g., tertiary amine surfactant (Ethomeen C12), is 2.22% in DI water and 0.106% with LOD of 0.369 and 0.439 mM, respectively.

Preparation and structural characterization of zwitterionic surfactant intercalated into NiZn-layered hydroxide salts

Science.gov (United States)

Liu, Jiexiang; Wang, Jianlong; Zhang, Xiaoguang; Fang, Binbin; Hu, Pan; Zhao, Xuyang

2015-10-01

Three zwitterionic surfactants, dodecyl dimethyl carboxylbetaine (DCB), dodecyl dimethyl sulfobetaine (DSB) and N-dodecyl-β-aminoprpionate (DAP), intercalated into NiZn-layered hydroxide salts (NZL-DCB, NZL-DSB and NZL-DAP) were synthesized by the coprecipitation method. The effect of surfactant content, pH, temperature and time of hydrothermal treatment on preparation was investigated and discussed. The NZL-DCB, NZL-DSB and NZL-DAP were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry analysis and differential thermal analysis (TGA/DTA). The results showed that basal spacings of NZL-DCB, NZL-DSB and NZL-DAP were around 3.45, 3.68 and 3.94 nm, respectively. DCB, DSB and DAP probably form an overlapped bilayer in the gallery. TGA/DTA data indicated that NZL-DCB, NZL-DSB and NZL-DAP displayed three loss weight stages: loss of adsorbed and structural water, dehydroxylation of matrix and decomposition of nitrate ions, decomposition and combustion of surfactants. Furthermore, chemical analysis data, BET surface area and scanning electron microscopic (SEM) were also measured and analyzed.

Biosorption treatment of brackish water

International Nuclear Information System (INIS)

Rizwan, M.; Ali, M.; Tariq, M.I.; Rehman, F.U.; Karim, A.; Makshoof, M.; Farooq, R.

2010-01-01

Biosorptivity of different agricultural wastes have been evaluated for the treatment of brackish water and a new method, based on the principle of bio-sorption has been described. Wastes of the Saccharum officinarum, Moringa oleifera, Triticum aestivcum and Oryza sativa have been used in raw forms as well as after converting them into ash and activated carbon as biosorbents for treatment of brackish water in this study. Samples of brackish water have been analyzed before and after treatment for quality control parameters of water. A significant Improvement has been observed in quality control parameters of water after treatment. pH of the water samples slightly increased from 7.68 to 7.97 with different treatments. A substantial decrease in conductivity,. TDS, TH, concentrations of cations and anions was observed in the samples of brackish water after treatment with different biosorbents. (author)

Ubbelohde viscometer measurement of water-based Fe{sub 3}O{sub 4} magnetic fluid prepared by coprecipitation

Energy Technology Data Exchange (ETDEWEB)

Gu, H. [School of Physics and Electronic Engineering, Changshu Institute of Technology, Changshu 215500 (China); Tang, X. [College of Chemistry, Chemical Engineering and Materials Science and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China); Hong, R.Y., E-mail: rhong@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123 (China); College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350002 (China); Feng, W.G. [Suzhou Nanocomp Inc., Suzhou New District, Suzhou 215011 (China); Xie, H.D.; Chen, D.X. [Suzhou YouNuo Plastic Industry Co., Ltd., Suzhou 215021 (China); Badami, D. [Department of Chemical Engineering, University of Waterloo, Waterloo, Canada ON N2L 3G1 (Canada)

2013-12-15

Fe{sub 3}O{sub 4} nanoparticles were prepared by co-precipitation and coated by sodium dodecyl benzene sulfonate (SDBS) to obtain water-based magnetic fluid. The viscosity of the magnetic fluid was measured using an Ubbelohde viscometer. The effects of magnetic particles volume fraction, surfactant mass fraction and temperature on the viscosity were studied. Experimental results showed that the magnetic fluid with low magnetic particle volume fraction behaved as a Newtonian fluid and the viscosity of the magnetic fluid increased with an increase of the suspended magnetic particles volume fraction. The experimental data was compared with the results of a theoretically derived equation. The viscosity of the magnetic fluid also increased with an increase in surfactant mass portion, while it decreased with increasing temperature. Moreover, the viscosity increased with increasing the magnetic field intensity. Increasing the temperature and the surfactant mass fraction weakened the influence of the magnetic field on the viscosity of the magnetic fluid. - Highlights: • Fe{sub 3}O{sub 4} nanoparticles were prepared using co-precipitation and coated by sodium dodecyl benzene sulfonate to obtain water-based magnetic fluid. • The viscosity of different magnetic fluids was measured using an Ubbelohde viscometer. • The effects of magnetic particles volume fraction, surfactant mass fraction and temperature on the viscosity of magnetic fluids were studied.

Contribution of Seawater Surfactants to Generated Primary Marine Aerosol Particles

Science.gov (United States)

Frossard, A. A.; Gerard, V.; Duplessis, P.; Kinsey, J. D.; Lu, X.; Zhu, Y.; Bisgrove, J.; Maben, J. R.; Long, M. S.; Chang, R.; Beaupre, S. R.; Kieber, D. J.; Keene, W. C.; Noziere, B.; Cohen, R. C.

2017-12-01

Surfactants account for minor fractions of total organic carbon in the ocean but may have major impacts on the surface tension of bursting bubbles at the sea surface that drive the production of primary marine aerosol particles (PMA). Surfactants associated with marine aerosol may also significantly reduce the surface tension of water thereby increasing the potential for cloud droplet activation and growth. During September and October 2016, PMA were produced from bursting bubbles in seawater using a high capacity generator at two biologically productive and two oligotrophic stations in the western North Atlantic, as part of a cruise on the R/V Endeavor. Surfactants were extracted from paired PMA and seawater samples, and their ionic compositions, total concentrations, and critical micelle concentrations (CMC) were quantified and compared for the four hydrographic stations. Higher surfactant concentrations were determined in the aerosol produced from biologically productive seawater compared to oligotrophic seawater, and the surfactants extracted from productive seawater were stronger (had lower CMCs) than those in the oligotrophic seawater. Surfactants associated with PMA and seawater in productive regions also varied over diel cycles, whereas those in the oligotrophic regions did not. This work demonstrates a direct link between surfactants in seawater and those in PMA.

Aluminum-Based Water Treatment Residue Reuse for Phosphorus Removal

Directory of Open Access Journals (Sweden)

Lai Yoke Lee

2015-04-01

Full Text Available Aluminum-based water treatment residue (Al-WTR generated during the drinking water treatment process is a readily available recycled material with high phosphorus (P adsorption capacity. The P adsorption capacity of Al-WTR generated from Singapore’s water treatment plant was evaluated with reference to particle size range, adsorption pH and temperature. Column tests, with WTR amendments in sand with and without compost, were used to simulate the bioretention systems. The adsorption rate decreased with increasing WTR sizes. Highest P adsorption capacity, 15.57 mg PO43−-P/g WTR, was achieved using fine WTR particles (>50% particles at less than 0.30 mm. At pH 4, the contact time required to reduce effluent P concentration to below the detectable range was half compared with pH 7 and 9. The adsorption rate observed at 40 ± 2 °C was 21% higher compared with that at 30 ± 2 °C. Soil mixes amended with 10% WTR and compost were able to maintain consistently high (90% total phosphorus (TP removal efficiency at a TP load up to 6.45 g/m3. In contrast, TP removal efficiencies associated with columns without WTR amendment decreased to less than 45% as the TP load increased beyond 4.5 g/m3. The results showed that WTR application is beneficial for enhanced TP removal in bioretention systems.

The role of electrolyte and polyelectrolyte on the adsorption of the anionic surfactant, sodium dodecylbenzenesulfonate, at the air-water interface.

Science.gov (United States)

Zhang, X L; Taylor, D J F; Thomas, R K; Penfold, J

2011-04-15

The role of the polyelectrolyte, poly(ethyleneimine), PEI, and the electrolytes NaCl and CaCl(2), on the adsorption of the anionic surfactant, sodium dodecylbenzenesulfonate, LAS, at the air-water interface have been investigated by neutron reflectivity and surface tension. The surface tension data for the PEI/LAS mixtures are substantially affected by pH and the addition of electrolyte, and are consistent with a strong adsorption of surface polymer/surfactant complexes down to relatively low surfactant concentrations. The effects are most pronounced at high pH, and this is confirmed by the adsorption data obtained directly from neutron reflectivity. However, the effects of the addition of PEI and electrolyte on the LAS adsorption are not as pronounced as previously reported for PEI/SDS mixtures. This is attributed primarily to the steric hindrance of the LAS phenyl group resulting in a reduction in the ion-dipole attraction between the LAS sulfonate and amine groups that dominates the interaction at high pH. Copyright © 2011 Elsevier Inc. All rights reserved.

Ultra-trace determination of gold nanoparticles in environmental water by surfactant assisted dispersive liquid liquid microextraction coupled with electrothermal vaporization-inductively coupled plasma-mass spectrometry

Science.gov (United States)

Liu, Ying; He, Man; Chen, Beibei; Hu, Bin

2016-08-01

A new method by coupling surfactant assisted dispersive liquid liquid microextraction (SA-DLLME) with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was proposed for the analysis of gold nanoparticles (AuNPs) in environmental water samples. Effective separation of AuNPs from ionic gold species was achieved by using sodium thiosulphate as a complexing agent. Various experimental parameters affecting SA-DLLME of AuNPs, such as the organic solvent, organic solvent volume, pH of the sample, the kind of surfactant, surfactant concentration, vortex time, speed of centrifugation, centrifugation time, and different coating as well as sizes of AuNPs were investigated carefully. Furthermore, the interference of coexisting ions, dissolved organic matter (DOM) and other metal nanoparticles (NPs) were studied. Under the optimal conditions, a detection limit of 2.2 ng L- 1 and an enrichment factor of 152-fold was achieved for AuNPs, and the original morphology of the AuNPs could be maintained during the extraction process. The developed method was successfully applied for the analysis of AuNPs in environmental water samples, including tap water, the East Lake water, and the Yangtze River water, with recoveries in the range of 89.6-102%. Compared with the established methods for metal NPs analysis, the proposed method has the merits of simple and fast operation, low detection limit, high selectivity, good tolerance to the sample matrix and no digestion or dilution required. It provides an efficient quantification methodology for monitoring AuNPs' pollution in the environmental water and evaluating its toxicity.

A level-set method for two-phase flows with soluble surfactant

Science.gov (United States)

Xu, Jian-Jun; Shi, Weidong; Lai, Ming-Chih

2018-01-01

A level-set method is presented for solving two-phase flows with soluble surfactant. The Navier-Stokes equations are solved along with the bulk surfactant and the interfacial surfactant equations. In particular, the convection-diffusion equation for the bulk surfactant on the irregular moving domain is solved by using a level-set based diffusive-domain method. A conservation law for the total surfactant mass is derived, and a re-scaling procedure for the surfactant concentrations is proposed to compensate for the surfactant mass loss due to numerical diffusion. The whole numerical algorithm is easy for implementation. Several numerical simulations in 2D and 3D show the effects of surfactant solubility on drop dynamics under shear flow.

Boundary layers of aqueous surfactant and block copolymer solutions against hydrophobic and hydrophilic solid surfaces

International Nuclear Information System (INIS)

Steitz, Roland; Schemmel, Sebastian; Shi Hongwei; Findenegg, Gerhard H

2005-01-01

The boundary layer of aqueous surfactants and amphiphilic triblock copolymers against flat solid surfaces of different degrees of hydrophobicity was investigated by neutron reflectometry (NR), grazing incidence small angle neutron scattering (GISANS) and atomic force microscopy (AFM). Solid substrates of different hydrophobicities were prepared by appropriate surface treatment or by coating silicon wafers with polymer films of different chemical natures. For substrates coated with thin films (20-30 nm) of deuterated poly(styrene) (water contact angle θ w ∼ 90), neutron reflectivity measurements on the polymer/water interface revealed a water depleted liquid boundary layer of 2-3 nm thickness and a density about 90% of the bulk water density. No pronounced depletion layer was found at the interface of water against a less hydrophobic polyelectrolyte coating (θ w ∼ 63). It is believed that the observed depletion layer at the hydrophobic polymer/water interface is a precursor of the nanobubbles which have been observed by AFM at this interface. Decoration of the polymer coatings by adsorbed layers of nonionic C m E n surfactants improves their wettability by the aqueous phase at surfactant concentrations well below the critical micellar concentration (CMC) of the surfactant. Here, GISANS experiments conducted on the system SiO 2 /C 8 E 4 /D 2 O reveal that there is no preferred lateral organization of the C 8 E 4 adsorption layers. For amphiphilic triblock copolymers (PEO-PPO-PEO) it is found that under equilibrium conditions they form solvent-swollen brushes both at the air/water and the solid/water interface. In the latter case, the brushes transform to uniform, dense layers after extensive rinsing with water and subsequent solvent evaporation. The primary adsorption layers maintain properties of the precursor brushes. In particular, their thickness scales with the number of ethylene oxide units (EO) of the block copolymer. In the case of dip-coating without

The multiphase flow system used in exploiting depleted reservoirs: water-based Micro-bubble drilling fluid

International Nuclear Information System (INIS)

Zheng Lihui; He Xiaoqing; Wang Xiangchun; Fu Lixia

2009-01-01

Water-based micro-bubble drilling fluid, which is used to exploit depleted reservoirs, is a complicated multiphase flow system that is composed of gas, water, oil, polymer, surfactants and solids. The gas phase is separate from bulk water by two layers and three membranes. They are 'surface tension reducing membrane', 'high viscosity layer', 'high viscosity fixing membrane', 'compatibility enhancing membrane' and 'concentration transition layer of liner high polymer (LHP) and surfactants' from every gas phase centre to the bulk water. 'Surface tension reducing membrane', 'high viscosity layer' and 'high viscosity fixing membrane' bond closely to pack air forming 'air-bag', 'compatibility enhancing membrane' and 'concentration transition layer of LHP and surfactants' absorb outside 'air-bag' to form 'incompact zone'. From another point of view, 'air-bag' and 'incompact zone' compose micro-bubble. Dynamic changes of 'incompact zone' enable micro-bubble to exist lonely or aggregate together, and lead the whole fluid, which can wet both hydrophilic and hydrophobic surface, to possess very high viscosity at an extremely low shear rate but to possess good fluidity at a higher shear rate. When the water-based micro-bubble drilling fluid encounters leakage zones, it will automatically regulate the sizes and shapes of the bubbles according to the slot width of fracture, the height of cavern as well as the aperture of openings, or seal them by making use of high viscosity of the system at a very low shear rate. Measurements of the rheological parameters indicate that water-based micro-bubble drilling fluid has very high plastic viscosity, yield point, initial gel, final gel and high ratio of yield point and plastic viscosity. All of these properties make the multiphase flow system meet the requirements of petroleum drilling industry. Research on interface between gas and bulk water of this multiphase flow system can provide us with information of synthesizing effective

Measurement of the Surface Dilatational Viscosity of an Insoluble Surfactant Monolayer at the Air/Water Interface Using a Pendant Drop Apparatus

Science.gov (United States)

Lorenzo, Jose; Couzis, Alex; Maldarelli, Charles; Singh, Bhim S. (Technical Monitor)

2000-01-01

When a fluid interface with surfactants is at rest, the interfacial stress is isotropic (as given by the equilibrium interfacial tension), and is described by the equation of state which relates the surface tension to the surfactant surface concentration. When surfactants are subjected to shear and dilatational flows, flow induced interaction of the surfactants; can create interfacial stresses apart from the equilibrium surface tension. The simplest relationship between surface strain rate and surface stress is the Boussinesq-Scriven constitutive equation completely characterized by three coefficients: equilibrium interfacial tension, surface shear viscosity, and surface dilatational viscosity Equilibrium interfacial tension and surface shear viscosity measurements are very well established. On the other hand, surface dilatational viscosity measurements are difficult because a flow which change the surface area also changes the surfactant surface concentration creating changes in the equilibrium interfacial tension that must be also taken into account. Surface dilatational viscosity measurements of existing techniques differ by five orders of magnitude and use spatially damped surface waves and rapidly expanding bubbles. In this presentation we introduce a new technique for measuring the surface dilatational viscosity by contracting an aqueous pendant drop attached to a needle tip and having and insoluble surfactant monolayer at the air-water interface. The isotropic total tension on the surface consists of the equilibrium surface tension and the tension due to the dilation. Compression rates are undertaken slow enough so that bulk hydrodynamic stresses are small compared to the surface tension force. Under these conditions we show that the total tension is uniform along the surface and that the Young-Laplace equation governs the drop shape with the equilibrium surface tension replaced by the constant surface isotropic stress. We illustrate this technique using

The Optimization-Based Design and Synthesis of Water Network for Water Management in an Industrial Process: Refinery Effluent Treatment Plant

DEFF Research Database (Denmark)

Sueviriyapan, Natthapong; Siemanond, Kitipat; Quaglia, Alberto

2014-01-01

The increasing awareness of the sustainability of water resources has become an important issue. Many process industries contribute to high water consumption and wastewater generation. Problems in industrial water management include the processing of complex contaminants in wastewater, selection...... of wastewater treatment technologies, as well as water allocation, limited reuse, and recycling strategies. Therefore, a water and wastewater treatment network design requires the integration of both economic and environmental perspectives. The aim of this work was to modify and develop a generic model......-based synthesis process for a water/wastewater treatment network design problem utilizing the framework of Quaglia et al. (2013) in order to effectively design, synthesize, and optimize an industrial water management problem using different scenarios (both existing and retrofit system design). The model...

Mineral-Surfactant Interactions for Minimum Reagents Precipitation and Adsorption for Improved Oil Recovery

Energy Technology Data Exchange (ETDEWEB)

P. Somasundaran

2008-09-20

Chemical EOR can be an effective method for increasing oil recovery and reducing the amount of produced water; however, reservoir fluids are chemically complex and may react adversely to the polymers and surfactants injected into the reservoir. While a major goal is to alter rock wettability and interfacial tension between oil and water, rock-fluid and fluid-fluid interactions must be understood and controlled to minimize reagent loss, maximize recovery and mitigate costly failures. The overall objective of this project was to elucidate the mechanisms of interactions between polymers/surfactants and the mineral surfaces responsible for determining the chemical loss due to adsorption and precipitation in EOR processes. The role of dissolved inorganic species that are dependent on the mineralogy is investigated with respect to their effects on adsorption. Adsorption, wettability and interfacial tension are studied with the aim to control chemical losses, the ultimate goal being to devise schemes to develop guidelines for surfactant and polymer selection in EOR. The adsorption behavior of mixed polymer/surfactant and surfactant/surfactant systems on typical reservoir minerals (quartz, alumina, calcite, dolomite, kaolinite, gypsum, pyrite, etc.) was correlated to their molecular structures, intermolecular interactions and the solution conditions such as pH and/or salinity. Predictive models as well as general guidelines for the use of polymer/surfactant surfactant/surfactant system in EOR have been developed The following tasks have been completed under the scope of the project: (1) Mineral characterization, in terms of SEM, BET, size, surface charge, and point zero charge. (2) Study of the interactions among typical reservoir minerals (quartz, alumina, calcite, dolomite, kaolinite, gypsum, pyrite, etc.) and surfactants and/or polymers in terms of adsorption properties that include both macroscopic (adsorption density, wettability) and microscopic (orientation

Equilibrium of adsorption of mixed milk protein/surfactant solutions at the water/air interface.

Science.gov (United States)

Kotsmar, C; Grigoriev, D O; Xu, F; Aksenenko, E V; Fainerman, V B; Leser, M E; Miller, R

2008-12-16

Ellipsometry and surface profile analysis tensiometry were used to study and compare the adsorption behavior of beta-lactoglobulin (BLG)/C10DMPO, beta-casein (BCS)/C10DMPO and BCS/C12DMPO mixtures at the air/solution interface. The adsorption from protein/surfactant mixed solutions is of competitive nature. The obtained adsorption isotherms suggest a gradual replacement of the protein molecules at the interface with increasing surfactant concentration for all studied mixed systems. The thickness, refractive index, and the adsorbed amount of the respective adsorption layers, determined by ellipsometry, decrease monotonically and reach values close to those for a surface covered only by surfactant molecules, indicating the absence of proteins from a certain surfactant concentration on. These results correlate with the surface tension data. A continuous increase of adsorption layer thickness was observed up to this concentration, caused by the desorption of segments of the protein and transforming the thin surface layer into a rather diffuse and thick one. Replacement and structural changes of the protein molecules are discussed in terms of protein structure and surface activity of surfactant molecules. Theoretical models derived recently were used for the quantitative description of the equilibrium state of the mixed surface layers.

Studies of the ionizing radiation effects on the effluents acute toxicity due to anionic surfactants

International Nuclear Information System (INIS)

Moraes, Maria Cristina Franco de

2004-01-01

Several studies have shown the negative effects of surfactants, as detergents active substance, when discharged on biological sewage wastewater treatment plants. High toxicity may represent a lower efficiency for biological treatment. When surfactants are in aquatic environment they may induce a loss of grease revetment on birds (feather). Depending on the surfactant concentration, several damages to all biotic systems can happen. Looking for an alternative technology for wastewater treatment, efficient for surfactant removal, the present work applied ionizing radiation as an advanced oxidation process for affluents and effluents from Suzano Treatment Station. Such wastewater samples were submitted to radiation using an electron beam from a Dynamic Electron Beam Accelerator from Instituto de Pesquisas Energeticas e Nucleares. In order to assess this proposed treatment efficacy, it was performed acute toxicity evaluation with two test-organisms, the crustacean Daphnia similis and the luminescent bacteria Vibrio fischeri. The studied effluents were: one from a chemical industry (IND), three from sewage plant (affluents - GG, GM and Guaio) and the last biologically treated secondary effluent (EfF), discharged at Tiete river. The applied radiation doses varied from 3 kGy to 50 kGy, being 50 kGy enough for surfactant degradation contained at industrial effluent. For GG, GM and Guaio samples, doses of 6 kGy and 10 kGy were efficient for surfactant and toxicity reduction, representing an average removal that varied from 71.80% to 82.76% and toxicity from 30% to 91% for most the effluents. The final effluent was less toxic than the others and the radiation induced an average 11% removal for anionic surfactant. The industrial effluents were also submitted to an aeration process in order to quantify the contribution of surfactant to the whole sample toxicity, once it was partially removed as foam and several fractions were evaluated for toxicity. (author)

Characteristic features of heterophase polymerisation of styrene with simultaneous formation of surfactants at the interface

International Nuclear Information System (INIS)

Prokopov, Nikolai I; Gritskova, Inessa A

2001-01-01

Data on the heterophase polymerisation of styrene under conditions of surfactant formation at the monomer-water interface are generalised. A new, in principle, approach is proposed the essence of which is to obtain a monomer emulsion simultaneously with the synthesis of an emulsifier at the monomer-water interface and with initiation of the polymerisation in the interfacial layer. The preparation of surfactants at the interface allows one to control efficiently the degree of dispersion and the stability of the emulsions formed. By varying the nature of the acid and the metal counter-ion used in the surfactant synthesis at the interface, it is possible to change the interfacial tension, to influence the microemulsification, disintegration of the monomer, and the formation of structure of interfacial adsorption layers. The mechanism of formation of polymer-monomeric particles as well as their diameter and size distribution depend substantially on the solubility of the resulting surfactants in water. The bibliography includes 47 references.

Characteristic features of heterophase polymerisation of styrene with simultaneous formation of surfactants at the interface

Energy Technology Data Exchange (ETDEWEB)

Prokopov, Nikolai I; Gritskova, Inessa A [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

2001-09-30

Data on the heterophase polymerisation of styrene under conditions of surfactant formation at the monomer-water interface are generalised. A new, in principle, approach is proposed the essence of which is to obtain a monomer emulsion simultaneously with the synthesis of an emulsifier at the monomer-water interface and with initiation of the polymerisation in the interfacial layer. The preparation of surfactants at the interface allows one to control efficiently the degree of dispersion and the stability of the emulsions formed. By varying the nature of the acid and the metal counter-ion used in the surfactant synthesis at the interface, it is possible to change the interfacial tension, to influence the microemulsification, disintegration of the monomer, and the formation of structure of interfacial adsorption layers. The mechanism of formation of polymer-monomeric particles as well as their diameter and size distribution depend substantially on the solubility of the resulting surfactants in water. The bibliography includes 47 references.

Antioxidant poly(lactic-co-glycolic) acid nanoparticles made with α-tocopherol-ascorbic acid surfactant.

Science.gov (United States)

Astete, Carlos E; Dolliver, Debra; Whaley, Meocha; Khachatryan, Lavrent; Sabliov, Cristina M

2011-12-27

The goal of the study was to synthesize a surfactant made of α-tocopherol (vitamin E) and ascorbic acid (vitamin C) of antioxidant properties dubbed as EC, and to use this surfactant to make poly(lactic-co-glycolic) acid (PLGA) nanoparticles. Self-assembled EC nanostructures and PLGA-EC nanoparticles were made by nanoprecipitation, and their physical properties (size, size distribution, morphology) were studied at different salt concentrations, surfactant concentrations, and polymer/surfactant ratios. EC surfactant was shown to form self-assembled nanostructures in water with a size of 22 to 138 nm in the presence of sodium chloride, or 12 to 31 nm when synthesis was carried out in sodium bicarbonate. Polymeric PLGA-EC nanoparticles presented a size of 90 to 126 nm for 40% to 120% mass ratio PLGA to surfactant. For the same mass ratios, the PLGA-Span80 formed particles measured 155 to 216 nm. Span80 formed bilayers, whereas EC formed monolayers at the interfaces. PLGA-EC nanoparticles and EC showed antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay measurements using UV and EPR techniques, antioxidant activity which is not characteristic to commercially available Span80. The thiobarbituric acid reactive substances (TBARS) assay for lipid peroxidation showed that PLGA nanoparticles with EC performed better as antioxidants than the EC nanoassembly or the free vitamin C. Nanoparticles were readily internalized by HepG2 cells and were localized in the cytoplasm. The newly synthesized EC surfactant was therefore found successful in forming uniform, small size polymeric nanoparticles of intrinsic antioxidant properties.

Compatibility of the ultraviolet light-ozone system for laundry waste water treatment in nuclear power plants

International Nuclear Information System (INIS)

Matsuo, Toshiaki; Nishi, Takashi; Matsuda, Masami; Izumida, Tatsuo

1997-01-01

As an alternative treatment system for laundry waste water in nuclear power plants, a system was chosen in which such organic compounds as surfactant would be oxidized by ultraviolet (UV) light and ozone. The system compatibility, UV light source, and dissolved ozone concentration were examined through experiments. First, ozone gas was absorbed in the waste water. After the dissolved ozone concentration equilibrated at the desired value, the waste water was irradiated by a mercury lamp. Then, the time dependence of the concentrations of the organic compounds, the dissolved ozone, and the hydrogen peroxide were measured to estimate the treatment rate of the system. The mercury lamp with a 10 5 -Pa vapor pressure achieved large UV radiation and a treatment rate increase, leading to a compatible system without secondary waste generation. The effect of the dissolved ozone concentration on the treatment rate was saturated when concentration was >3.3 x 10 -4 mol/10 -3 m 3 at the time UV radiation was started. Numerical results indicated the saturation was due to hydrogen peroxide generation, which prevents hydroxyl radical generation

Optimization of surfactant-aided remediation of industrially contaminated soils

International Nuclear Information System (INIS)

Joshi, M.M.; Lee, S.

1996-01-01

Soil matrices contaminated with polycyclic aromatic hydrocarbons (PAHs) abound at the sites of coke-oven gas plants, refineries, and many other major chemical industries. The removal of PAHs from soil using pure water, via soil washing (ex situ) or soil flushing (in situ), is quite ineffective due to their low solubility and hydrophobicity. However, addition of suitable surfactant(s) has been shown to increase the removal efficiency several fold. For the present work, the removal of PAHs occurring in industrially contaminated soil was studied. The objective was to use a nonionic surfactant solution for in situ soil flushing and to evaluate the optimal range of process parameters that can significantly increase the removal efficiency. The process parameters chosen were surfactant concentration, ratio of washing solution volume to soil weight, and temperature of washing solution. These parameters were found to have a significant effect on PAH removal from the contaminated soil and an optimal range was determined for each parameter under given washing conditions

Phase Behaviour Study of Swiftlet Nest Using Virgin Coconut Oil with Non-Ionic Surfactants

International Nuclear Information System (INIS)

Siti Salwa Abd Gani; Siti Zulaika Adisah; Siti Salwa Abd Gani

2015-01-01

Virgin coconut oil (VCO) is the oil that obtained from fresh and mature kernel of the coconut by mechanical or natural means with or without the application of heat, which does not lead to alteration of the nature of the oil. It have advantages such as strengthens the immune system because of its lauric acid content. It also has medium-chain fatty acids which heighten metabolism and energy, thus stimulating the thyroid. Swiftlet nest as an active ingredient need to be dispersed in a carrier system. Thus, ternary phase diagrams were constructed to find the suitable and stable system for it. The phase behavior of systems has been investigated by constructing ternary phase diagrams consisting of non-ionic surfactants/VCO:bird nest/water. The surfactants used were Sorbitan tri-oleate (Span 85), Sorbitan mono-oleate (Span 80), Sorbitan monolaurate (Span 20), Polyoxyethylene(20) sorbitan tri-oleate (Tween 85) and Polyoxyethylene (20) sorbitan mono-oleate (Tween 80). These systems include several phase regions such as homogeneous, isotropic, two-phase and three-phase regions. Different hydrophilic lipophilic balance (HLB) value of non-ionic surfactants exhibit different ternary diagram characteristics. A lower HLB shows a more oil-soluble and a more water-soluble surfactant (larger homogeneous and isotropic region in ternary phase diagrams) whereas high value of HLB shows the reverse of that result. The results show that the T85/VCO:bird nest/water system gave better performance than the other four individual surfactant systems. As a conclusion, high hydrophilic lipophilic balance (HLB) values of surfactant were found to be a good surfactant for the formulation of VCO:bird nest emulsion for cosmetic and pharmaceutical purposes. (author)

Interactions of short chain phenylalkanoic acids within ionic surfactant micelles in aqueous media

Directory of Open Access Journals (Sweden)

Naeem Kashif

2012-01-01

Full Text Available % SDS KR nema Solubilization and interactions of phenylalkanoic acids induced by cationic surfactant, cetyltrimethylammonium bromide (CTAB and an anionic surfactant, sodium dodecyl sulfate (SDS was investigated spectrophotometrically at 25.0°C. The UV spectra of the additives (acids were measured with and without surfactant above and below critical micelle concentration (cmc of the surfactant. The presence of alkyl chain in phenylalkanoic acids is responsible for hydrophobic interaction resulting in shift of the spectra towards longer wavelength (red shift. The value of partition coefficient (Kx between the bulk water and surfactant micelles and in turn standard free energy change of solubilization (ΔGpº were also estimated by measuring the differential absorbance (ΔA of the additives in micellar solutions.

The Role of Some Retention Aids in Water Based Gravure Printing

International Nuclear Information System (INIS)

El-Sherbiny, S.; Morsy, F.A.; Abdel- Sayed, E.S.

2005-01-01

Several commercial retention systems employing either synthetic or natural additives are now able to achieve an acceptable level of filler retention even during high speed paper forming. However, despite their importance, there have been very few reports in the literature regarding the influence of different retention aids on gravure water based ink printability. In the current work, a series of uncoated hand sheets containing the retention aids rosin aids rosin-alum, cationic starch, polyacrylamide and chitosan were prepared under controlled ph conditions. Chitosan is a natural additive only very recently employed in commercial papermaking systems. After printing with two water based ink systems, both printability and print quality were then assessed in terms of print density, gloss and ink transfer. The effect of surfactant addition to gravure water based ink was also studied. The results showed that the amount of ink transferred and the print density both decreased as the percentage of the selected additives increased. The addition of chitosan to the paper furnish led to a substantial decrease in both the amount of ink transferred and the print density compared to the other additives. Conversely, the presence of surfactant in the printing ink enhanced the print density and also increased the amount of ink transferred. In addition, results obtained demonstrated that printing with water based ink greatly decreased the print gloss in comparison to the paper gloss. Increasing the addition level of the selected additives led to an increase of print gloss due to a decrease in the amount of ink transferred. Increasing the ph of the pulp suspension containing 1 % of the selected additives increased the print density in all cases, except when using cationic starch

Adsorption of diclofenac onto organoclays: Effects of surfactant and environmental (pH and temperature) conditions

OpenAIRE

De Oliveira , Tiago; Guégan , Régis; Thiebault , Thomas; Le Milbeau , Claude; Muller , Fabrice; Teixeira , Vinicius; Giovanela , Marcelo; Boussafir , Mohammed

2017-01-01

Accepted Manuscript; International audience; Among pharmaceutical products (PPs) recalcitrant to water treatments, diclofenac shows a high toxicity and remains at high concentration in natural aquatic environments. The aim of this study concerns the understanding of the adsorption mechanism of this anionic PP onto two organoclays prepared with two long-alkyl chains cationic surfactants showing different chemical nature for various experimental pH and temperature conditions. The experimental d...

Development of sustainable water treatment technology using scientifically based calculated indexes of source water quality indicators

Directory of Open Access Journals (Sweden)

А. С. Трякина

2017-10-01

Full Text Available The article describes selection process of sustainable technological process flow chart for water treatment procedure developed on scientifically based calculated indexes of quality indicators for water supplied to water treatment facilities. In accordance with the previously calculated values of the indicators of the source water quality, the main purification facilities are selected. A more sustainable flow chart for the modern water quality of the Seversky Donets-Donbass channel is a two-stage filtering with contact prefilters and high-rate filters. The article proposes a set of measures to reduce such an indicator of water quality as permanganate oxidation. The most suitable for these purposes is sorption purification using granular activated carbon for water filtering. The increased water hardness is also quite topical. The method of ion exchange on sodium cation filters was chosen to reduce the water hardness. We also evaluated the reagents for decontamination of water. As a result, sodium hypochlorite is selected for treatment of water, which has several advantages over chlorine and retains the necessary aftereffect, unlike ozone. A technological flow chart with two-stage purification on contact prefilters and two-layer high-rate filters (granular activated carbon - quartz sand with disinfection of sodium hypochlorite and softening of a part of water on sodium-cation exchangers filters is proposed. This technological flow chart of purification with any fluctuations in the quality of the source water is able to provide purified water that meets the requirements of the current sanitary-hygienic standards. In accordance with the developed flow chart, guidelines and activities for the reconstruction of the existing Makeevka Filtering Station were identified. The recommended flow chart uses more compact and less costly facilities, as well as additional measures to reduce those water quality indicators, the values of which previously were in

Polymeric surfactants for enhanced oil recovery : A review

NARCIS (Netherlands)

Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

Chemical enhanced oil recovery (EOR) is surely a topic of interest, as conventional oil resources become more scarce and the necessity of exploiting heavy and unconventional oils increases. EOR methods based on polymer flooding, surfactant-polymer flooding and alkali-surfactant-polymer flooding are

Performance of Surfactant Methyl Ester Sulphonate solution for Oil Well Stimulation in reservoir sandstone TJ Field

Science.gov (United States)

Eris, F. R.; Hambali, E.; Suryani, A.; Permadi, P.

2017-05-01

Asphaltene, paraffin, wax and sludge deposition, emulsion and water blocking are kinds ofprocess that results in a reduction of the fluid flow from the reservoir into formation which causes a decrease of oil wells productivity. Oil well Stimulation can be used as an alternative to solve oil well problems. Oil well stimulation technique requires applying of surfactant. Sodium Methyl Ester Sulphonate (SMES) of palm oil is an anionic surfactant derived from renewable natural resource that environmental friendly is one of potential surfactant types that can be used in oil well stimulation. This study was aimed at formulation SMES as well stimulation agent that can identify phase transitions to phase behavior in a brine-surfactant-oil system and altered the wettability of rock sandstone and limestone. Performance of SMES solution tested by thermal stability test, phase behavioral examination and rocks wettability test. The results showed that SMES solution (SMES 5% + xylene 5% in the diesel with addition of 1% NaCl at TJformation water and SMES 5% + xylene 5% in methyl ester with the addition of NaCl 1% in the TJ formation water) are surfactant that can maintain thermal stability, can mostly altered the wettability toward water-wet in sandstone reservoir, TJ Field.

Cytogenotoxicity screening of source water, wastewater and treated water of drinking water treatment plants using two in vivo test systems: Allium cepa root based and Nile tilapia erythrocyte based tests.

Science.gov (United States)

Hemachandra, Chamini K; Pathiratne, Asoka

2017-01-01

Biological effect directed in vivo tests with model organisms are useful in assessing potential health risks associated with chemical contaminations in surface waters. This study examined the applicability of two in vivo test systems viz. plant, Allium cepa root based tests and fish, Oreochromis niloticus erythrocyte based tests for screening cytogenotoxic potential of raw source water, water treatment waste (effluents) and treated water of drinking water treatment plants (DWTPs) using two DWTPs associated with a major river in Sri Lanka. Measured physico-chemical parameters of the raw water, effluents and treated water samples complied with the respective Sri Lankan standards. In the in vivo tests, raw water induced statistically significant root growth retardation, mitodepression and chromosomal abnormalities in the root meristem of the plant and micronuclei/nuclear buds evolution and genetic damage (as reflected by comet scores) in the erythrocytes of the fish compared to the aged tap water controls signifying greater genotoxicity of the source water especially in the dry period. The effluents provoked relatively high cytogenotoxic effects on both test systems but the toxicity in most cases was considerably reduced to the raw water level with the effluent dilution (1:8). In vivo tests indicated reduction of cytogenotoxic potential in the tested drinking water samples. The results support the potential applications of practically feasible in vivo biological test systems such as A. cepa root based tests and the fish erythrocyte based tests as complementary tools for screening cytogenotoxicity potential of the source water and water treatment waste reaching downstream of aquatic ecosystems and for evaluating cytogenotoxicity eliminating efficacy of the DWTPs in different seasons in view of human and ecological safety. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of a non-ionic surfactant added to the soil structure on the biodegradation of aromatic hydrocarbons within the soil

Energy Technology Data Exchange (ETDEWEB)

Aronstein, B N [Lab. of Soil Microbiology, Dept. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY (United States); Alexander, M [Lab. of Soil Microbiology, Dept. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY (United States)

1993-06-01

A study was conducted to determine whether a non-ionic surfactant (Novel II 1412-56) added to the surface of Lima silt loam would enhance the biodegradation of penanthrene and biphenyl present within the soil. Water containing the surfactant at concentrations of 10 and 100 [mu]g/ml was pumped through the soil. At 10 [mu]g/ml, Novel II 1412-56 markedly enhanced the rate and extent of phenanthrene mineralization and the extent but not the initial rate of biphenyl mineralization. The stimulation was less if the water added to the soil surface contained 100 [mu]g surfactant/ml. Addition of the surfactant at the two concentrations did not result in leaching of either phenanthrene or biphenyl, but products of the degradation were found in the soil leachate with or without the surfactant. We suggest that surfactants at low concentrations may be useful for in-situ bioremediation of sites contaminated with hydrophobic pollutants without causing movement of the parent compounds to ground-waters. (orig.)

Development of Microemulsion Based Nabumetone Transdermal Delivery For Treatment of Arthritis.

Science.gov (United States)

Jagdale, Swati; Deore, Gokul; Chabukswar, Anuruddha

2018-02-26

Background Nabumetone is biopharmaceutics classification system (BCS) class II drug, widely used in the treatment of osteoarthritis and rheumatoid arthritis. The most frequently reported adverse reactions for the drug involve disturbance in gastrointestinal tract , diarrhea, dyspepsia and abdominal pain. Microemulgel has advantages of microemulsion for improving solubility for hydrophobic drug. Patent literature had shown that the work for drug has been carried on spray chilling, enteric coated tablet, and topical formulation which gave idea for present research work for development of transdermal delivery. Objective Objective of the present research work was to optimize transdermal microemulgel delivery for Nabumetone for treatment of arthritis. Method Oil, surfactant and co-surfactant were selected based on solubility study for the drug. Gelling agents used were Carbopol 934 and HPMC K100M. Optimization was carried out using 32 factorial design. Characterization and evaluation were carried out for microemulsion and microemulsion based gel. Results Field emission-scanning electron microscopy (FE-SEM) study of the microemulsion revealed globules of 50-200 nm size . Zeta potential -9.50 mV indicated good stability of microemulsion. Globule size measured by dynamic light scattering (zetasizer) was 160 nm. Design expert gave optimized batch as F7 which contain 0.2% w/w drug, 4.3% w/w liquid paraffin, 0.71% w/w tween 80, 0.35% w/w propylene glycol, 0.124% w/w Carbopol 934, 0.187% w/w HPMC K100M and 11.68% w/w water. In-vitro diffusion study for F7 batch showed 99.16±2.10 % drug release through egg membrane and 99.15±2.73% drug release in ex-vivo study. Conclusion Nabumetone microemulgel exhibiting good in-vitro and ex-vivo controlled drug release was optimized. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effect of surfactants or a water soluble polymer on the crystal transition of clarithromycin during a wet granulation process.

Science.gov (United States)

Nozawa, Kenji; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru

2015-11-10

To generate products containing a stable form of clarithromycin (CAM) (form II) regardless of the initial crystal form of CAM or type of granulation solvent, the effects of five surfactants, or a water-soluble polymer (macrogol 400) were determined on the crystal transition of CAM. The metastable form (form I) was kneaded with water, after adding surfactants, or a water-soluble polymer. Form II was also kneaded with ethanol, after adding the same additives. The resulting samples were analyzed by powder X-ray diffraction. Form I was completely converted to form II by a wet granulation using water with additives bearing polyoxyethylene chains such as polysorbate 80 (PS80), polyoxyl 40 stearate or macrogol 400. The granulation of the form II using ethanol with these additives did not result in a crystal transition to form I. Furthermore, CAM tablets were manufactured using granules with PS80, and these crystal forms and dissolution behaviors were investigated. As a result, the wet granulation of CAM with PS80 gave CAM tablets containing only form II and PS80 did not have any adverse effects on tablet characteristics. Therefore, these data suggests that the crystal form of CAM can be controlled to be form II using a wet granulation process with additives bearing polyoxyethylene chains regardless of the initial crystal form of CAM or type of granulation solvent. Copyright © 2015 Elsevier B.V. All rights reserved.

Surfactant-enhanced alkaline flooding for light oil recovery. Final report 1994--1995

Energy Technology Data Exchange (ETDEWEB)

Wasan, D.T.

1995-12-01

In this report, the authors present the results of their experimental and theoretical studies in surfactant-enhanced alkaline flooding for light oil recovery. The overall objective of this work is to develop a very cost-effective method for formulating a successful surfactant-enhanced alkaline flood by appropriately choosing mixed alkalis which form inexpensive buffers to obtain the desired pH (between 8.5 and 12.0) for ultimate spontaneous emulsification and ultralow interfacial tension. In addition, the authors have (1) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, (2) investigated the mechanisms for spontaneous emulsification, (3) developed a technique to monitor low water content in oil, and (4) developed a technique to study water-in-oil emulsion film properties, (5) investigated the effect of surfactant on the equilibrium and transient interfacial tension, (6) investigated the kinetics of oil removal from a silica surface, and (7) developed a theoretical interfacial activity model for determining equilibrium interfacial tension, accounting for added surfactant. The results of the studies conducted during the course of this project are summarized.

Polymer-surfactant interactions studied by titration microcalorimetry : Influence of polymer hydrophobicity, electrostatic forces, and surfactant aggregational state

NARCIS (Netherlands)

Kevelam, J; van Breemen, J.F.L.; Blokzijl, W.; Engberts, J.B.F.N.

1996-01-01

Isothermal titration microcalorimetry has been applied to investigate the interactions between hydrophobically-modified water-soluble polymers and surfactants. The following polymers were used in this study: poly(sodium acrylate-co-n-alkyl methacrylate) (A), where n-alkyl = C9H19, C12H25, and C18H37

Critical role of surfactants in the formation of digestively-ripened, ultra-small (r<2 nm) copper oxide quantum dots

Science.gov (United States)

Talluri, Bhusankar; Prasad, Edamana; Thomas, Tiju

2018-04-01

Synthesis of ultra-small (r photovoltaics to sensing. Digestive ripening (DR), a method for preparing uniformly-sized particles is critically influenced by nature and concentrations of the starting materials, solvent, and surfactant. To better understand the DR process there is a need to study the effect of each synthetic parameter. In this work, we investigate the effect of surfactant on a ceramic-DR process, with copper oxide as the chosen material. To study the influence of surfactant; aminoalcohols (triethanolamine, diethanolamine, monoethanolamine), alkylamines (ethyl amine) and aqua ligands are chosen. Digestively ripened quantum dots (QDs) are formed in case of all surfactants except ethyl amine and water. Aminoalchols based surfactants which contain both hydroxyl and amine moieties are efficient ligands (due to their chelation ability) for achieving DR. With the increase of denticity of the ligand, average size of QDs do not vary; however the variance in size does. QDs formed using aminoalchols are more monodispersed when compared to alkyl amine and aqua ligand systems. Furthermore, absorption and photoluminescence spectra suggest that choice of surfactant is important for achieving DR in ceramic nanostructures (when compared to other parameters). Hard-soft-acid-base-interactions between surfactant and copper oxide seem primarily responsible for the observed DR in copper oxide QDs. The absorption and photoluminescence spectra indicate that the energy migration and relaxation pathways taking place in DR QDs depend on the type of capping agent used.

Ozone/UV treatment to enhance biodegradation of surfactants in industrial wastewater. CRADA final report

Energy Technology Data Exchange (ETDEWEB)

Cline, J.E. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Sullivan, P.F. [Specialty Industrial Products, Inc., Spartanburg, SC (United States); Lovejoy, M.A.; Collier, J. [Sun River Innovations, Ltd., Lexington, KY (United States); Adams, C.D. [Univ. of Missouri, Rolla, MO (United States)

1996-10-01

The new owners of a surfactant manufacturing plant wanted to triple production but were limited by the plant`s wastewater treatment capacity. Mass balance calculations indicated that little aerobic biodegradation was occurring in the plant`s wastewater treatment system. Literature reviews and laboratory tests confirmed that as much as 60% of the plant`s products might resist aerobic biodegradation. Overall chemical losses, both solid and aqueous, were estimated at 3.8% of theoretical. Organic loadings to the wastewater treatment system were 170 kg/d of which 50 kg/d reached the biological treatment system. Pollution prevention measures have allowed a > 20% increase in production levels with a > 30% decrease in effluent volume and no increase in discharge of chemical oxygen demand (COD). A new dissolved air flotation (DAF) system removes 70% of the organic loading. Sludge volumes are lower by an order of magnitude than with the clarifier/drum-filter process it replaced.

Performance of Water-Based Liquid Scintillator: An Independent Analysis

Directory of Open Access Journals (Sweden)

D. Beznosko

2014-01-01

Full Text Available The water-based liquid scintillator (WbLS is a new material currently under development. It is based on the idea of dissolving the organic scintillator in water using special surfactants. This material strives to achieve the novel detection techniques by combining the Cerenkov rings and scintillation light, as well as the total cost reduction compared to pure liquid scintillator (LS. The independent light yield measurement analysis for the light yield measurements using three different proton beam energies (210 MeV, 475 MeV, and 2000 MeV for water, two different WbLS formulations (0.4% and 0.99%, and pure LS conducted at Brookhaven National Laboratory, USA, is presented. The results show that a goal of ~100 optical photons/MeV, indicated by the simulation to be an optimal light yield for observing both the Cerenkov ring and the scintillation light from the proton decay in a large water detector, has been achieved.

Particle-size dependent sorption and desorption of pesticides within a water-soil-nonionic surfactant system.

Science.gov (United States)

Wang, Peng; Keller, Arturo A

2008-05-01

Although nonionic surfactants have been considered in surfactant-aided soil washing systems, there is little information on the particle-size dependence of these processes, and this may have significant implications for the design of these systems. In this study, Triton-100 (TX) was selected to study its effect on the sorption and desorption of two pesticides (Atrazine and Diuron) from different primary soil size fractions (clay, silt, and sand fractions) under equilibrium sorption and sequential desorption. Soil properties, TX sorption, and pesticide sorption and desorption all exhibited significant particle-size dependence. The cation exchange capacity (CEC) of the bulk soils and the soil fractions determined TX sorption capacity, which in turn determined the desorption efficiency. Desorption of pesticide out of the clay raction is the limiting factor in a surfactant-aided washing system. The solubilization efficiency of the individual surfactant micelles decreased as the amount of surfactant added to the systems increased. Thus, instead of attempting to wash the bulk soil, a better strategy might be to either (1) use only the amount of surfactant that is sufficient to clean the coarse fraction, then separate the fine fraction, and dispose or treat it separately, or (2) to separate the coarse fractions mechanically and then treatthe coarse and fine fractions separately. These results may be applicable to many other hydrophobic organic compounds such as polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) strongly sorbed onto soils and sediments.

Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

Energy Technology Data Exchange (ETDEWEB)

Standnes, Dag Chun

2001-09-01

The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

Application of phase diagrams to obtain a new surfactant-based fracturing gel; Aplicacao de diagrama de fases para obtencao de um novo gel de fraturamento hidraulico

Energy Technology Data Exchange (ETDEWEB)

Dantas, Tereza N. de Castro; Santana, Vanessa C.; Dantas Neto, Afonso A.; Franca Neta, Luzia S. de; Albuquerque, Heraldo S. [Rio Grande do Norte Univ., Natal, RN (Brazil)]. E-mail: tereza@eq.ufrn.br

2003-07-01

Through pseudo ternary phases diagram was defined a gel area with the objective of obtaining a new surfactant-based fracturing gel. The surfactant used was synthesized from regional vegetable oil. Fracturing gel properties, like: viscosity, leak off coefficient and proppant-settling rate were analyzed. The obtained results with the surfactant-based gel had its properties compared with a HPG-based gel (hydroxypropyl guar). Rheological tests was accomplished at 100 s{sup -1} being varied the temperature from 26 to 86 deg C, where the surfactant-based gel showed great results. The leak off coefficient was determined by static filtration and the new gel presented smaller coefficient in relation to the HPG gel. The proppant-setting rate was also determined in the gel and, the surfactant-based gel showed good static proppant support. One can conclude that obtained gel presents compatible characteristics when compared with the HPG gel, without the inconvenience of leaving insoluble residues in the well. (author)

DISTRIBUTION OF A 2ND DOSE OF EXOGENOUS SURFACTANT IN RABBITS WITH SEVERE RESPIRATORY-FAILURE

NARCIS (Netherlands)

PLOTZ, FB; STEVENS, H; HEIKAMP, A; OETOMO, SB

Newborn infants with respiratory distress who fail to respond to surfactant treatment receive a second dose of surfactant. The effect of this strategy on the distribution of surfactant to the lung is unknown. We therefore investigated the distribution of the first (100 mg/kg body weight) and second

Pyrene removal from contaminated soil using electrokinetic process combined with surfactant

Directory of Open Access Journals (Sweden)

Seyed Enayat Hashemi

2015-07-01

Full Text Available Background: Pyrene is one of the stable polycyclic aromatic hydrocarbons that is considered as an important pollutants, because of extensive distribution in the environment and carcinogenic and mutagenic properties. Among the various treatment techniques, electrokinetic method is an environmental- friendly process for organic and mineral pollutants adsorbed to soil with fine pore size the same as clay and low hydraulic conductivity soils. For improving the efficiency of pyrene removal from soil, soulobilization of pyrene from soil could be used by surfactants. Materials and Methods : In this study, clay soil was selected as model because of the specific properties. Combined method using surfactant and electrokinetic was applied for pyrene removal from soil. Experiments were designed using response surface methodology (RSM, and effect of three variables includes surfactant concentration, voltage and surfactant type were evaluated for pyrene removal from contaminated soil. Results: Pyrene removal using anionic surfactants(SDS and nonionic surfactants(TX100 as a solubilizing agents has high removal efficiency. In the optimum condition with 95% confidence coefficient, utilizing mixed surfactants of sodium dodecyl sulfate and triton X-100 with the same volume, induced of 18.54 volt and 6.53 percent surfactant concentration have 94.6% pyrene removal efficiency. Conclusion:: Results of this study shows that electrokinetic process combined with surfactant as solubilizing agent could be applied as an efficient method for treating the pyrene-contaminated soils.

Effects of surfactants on bacteria and the bacterial degradation of alkanes in crude oil

Energy Technology Data Exchange (ETDEWEB)

Bruheim, Per

1998-12-31

This thesis investigates the effects of surfactants on the bacterial degradation of alkanes in crude oil. Several alkane oxidising Gram positive and Gram negative were tested for their abilities to oxidise alkanes in crude oil emulsified with surfactants. The surfactants used to make the oil in water emulsions were either of microbial or chemical origin. Oxidation rates of resting bacteria oxidising various crude oil in water emulsions were measured by Warburg respirometry. The emulsions were compared with non-emulsified oil to see which was the preferred substrate. The bacteria were pregrown to both the exponential and stationary phase of growth before harvesting and preparation for the Warburg experiments. 123 refs., 4 figs., 14 tabs.

Alkyl-imidazolium glycosides: non-ionic-cationic hybrid surfactants from renewable resources.

Science.gov (United States)

Salman, Abbas Abdulameer; Tabandeh, Mojtaba; Heidelberg, Thorsten; Hussen, Rusnah Syahila Duali; Ali, Hapipah Mohd

2015-08-14

A series of surfactants combining carbohydrate and imidazolium head groups were prepared and investigated on their assembly behavior. The presence of the imidazolium group dominated the interactions of the surfactants, leading to high CMCs and large molecular surface areas, reflected in curved rather than lamellar surfactant assemblies. The carbohydrate, on the other hand, stabilized molecular assemblies slightly and reduced the surface tension of surfactant solutions considerably. A comparative emulsion study discourages the use of pure alkyl imidazolium glycosides owing to reduced assembly stabilities compared with APGs. However, the surfactants are believed to have potential as component in carbohydrate based surfactant mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Suitability of Gray Water for Hydroponic Crop Production Following Biological and Physical Chemical and Biological Subsystems

Science.gov (United States)

Bubenheim, David L.; Harper, Lynn D.; Wignarajah, Kanapathipillai; Greene, Catherine

1994-01-01

in control hydroponic solution containing pure deionized water, no growth difference could be measured resulting from any of the recovered water treatments. Both biological treatment and VCD offer alternative technology approaches to recovering water from waste streams appropriate for input into a crop production system. A high level of crop performance (food, air, and water production) can be maintained with either processor; selection decisions can be based on other factors regarding system integration.

Mechanism of the immobilization of surfactants on polymeric surfaces by means of an argon plasma treatment: Influence of UV radiation

NARCIS (Netherlands)

Lens, J.P.; Spaay, B.; Terlingen, J.G.A.; Engbers, G.H.M.; Feijen, Jan

1999-01-01

The mechanism of the immobilization of the surfactant sodium 10-undecenoate (C11(:)) on poly(ethylene) (PE) by means of an argon plasma treatment has been investigated. In particular, the influence of the vacuum ultraviolet (UV) radiation emitted by the argon plasma on the immobilization was

Effect of the ODS-4 surfactant and its components on the efficiency of decontamination of solid surfaces

International Nuclear Information System (INIS)

Dvorak, J.; Duris, P.

1994-01-01

The efficiency was examined of the desorption of carrier-free traces of 147 Pm adsorbed from an acid aqueous solution at pH 2.6 in static conditions on a paint routinely applied to military facilities. The desorption was performed by using the ODS-4 decontamination and deactivation mixture and its components at various concentrations. It is concluded that the surfactant is not very well suited to the decontamination of solid surfaces contaminated with radionuclides which form the water-soluble component of radioactive contamination (in dependence on pH). This is due to the composition and the associated high alkalinity of the ODS-4 agent, which, however, is necessary if detoxication of toxic agents is required. In practice, however, the efficiency of decontamination will be appreciably higher because the military decontamination procedures involve dynamic (mechanical) treatment of the surfaces using brushes with flowing liquid, pressure application of the surfactant and water, moving baths, etc. (P.A.). 7 tabs., 2 figs., 10 refs

Influence of the chain length of surfactant in the modification of zeolites and clays. Removal of atrazine from water solutions.

Science.gov (United States)

Toledo-Jaldin, Helen Paola; Blanco-Flores, Alien; Sánchez-Mendieta, Víctor; Martín-Hernández, Osnieski

2017-08-30

Removal potentials of a surfactant modified zeolite (SMZ) and clay (SMC) for atrazine adsorption were evaluated. Materials were modified with hexadecyl trimethyl ammonium bromide (HDTMA-Br) and benzyl octadecyl dimethyl ammonium (BODA) chloride considering the critical micellar concentration (CMC) of each one (0.94 and 0.041 meq/L, respectively). The influence of the surfactant was analyzed in detail, particularly the formation of surfactant layers (complete or partial) connected with the length of the surfactant tail (16 and 18 methyl groups or number of carbons in the chain). Raw materials were characterized by XRD and Fourier transform infrared spectroscopy (FTIR), SMZ and SMC were analyzed by FTIR. Results obtained from kinetic adsorption experiments shown that equilibrium time is less for materials modified with HDTMA (8 h) than materials with BODA (10 and 12 h). Materials modified with the largest chain surfactant (BODA) showed more resistance to atrazine masse transference. The chemisorption was presented in the adsorption mechanisms of atrazine and adsorbent materials. Based on the results of adsorption isotherms Langmuir isotherms showed the better correlation coefficients value. The q max is greater for materials modified with BODA (0.9232 and 4.2448 mg/g) than for materials modified with HDTMA (0.6731 and 3.9121 mg/g). Therefore, SMZ and SMC modified with the largest chain surfactant has more affinity for the pesticide. The removal process at high concentration of atrazine depends of the partition process but at lower concentration, it occurs not only by this process but also by absorption process.

Experimental characterization of a silicone oil-in-water droplet generator based on a micro T-junction

Science.gov (United States)

Rostami, B.; Pulvirenti, B.; Puccetti, G.; Morini, G. L.

2017-01-01

This paper deals with the emulsion of two immiscible fluids in a micro T-junction. An opposed-flow micro T-junction obtained by means of square microchannels (with a side of 300 µm) fabricated in a pure fused glass chip has been used for the formation of silicone oil-in-water (O/W) droplets. The experimental results have been obtained by considering both pure deionized water and a mixture of deionized water and surfactant (Tween 20) as the continuous flow. The results shown in this paper highlight that the presence of surfactant, also in very small concentrations, is able to change drastically the flow patterns of the two-phase flow generated by the T-junction. Concentration in weight of Tween 20 between 1 and 2% in the continuous flow is able to promote highly monodispersed emulsions with low polydispersity, especially for low flow rate ratios between the dispersed and continuous phase flows. On the contrary, by avoiding the use of surfactant, a stratified flow is obtained. The experimental results obtained in this work have been used in order to link the depth ratio of the stratified flow and the non-dimensional length of the plugs in droplet-based flow to the flow rate ratio between the dispersed and continuous flows.

Current Issues and Challenges in the Use of Aerosolized Surfactant for Respiratory Distress Syndrome in the Newborns

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Dion Darius Samsudin

2013-08-01

Full Text Available BACKGROUND: Surfactant replacement therapy is a recognized treatment for respiratory distress syndrome (RDS in the newborns. Over the past 30 years, human and animal trials have been performed regarding administration of aerosolized surfactant to the injured lung, however the result has been unsatisfactory when compared with instilled surfactant delivery via endotracheal tube (ETT. This review aims to investigate the current issues, challenges and future recommendation of aerosolized surfactant therapy. CONTENT: Five randomized clinical trials in humans and 13 animal trials met the inclusion criteria and were reviewed. Most animal trials agree that this method of treatment is feasible. However, human trials presented conflicting results, and generally showed it to be ineffective. When compared with surfactant delivery via ETT, aerosolized surfactant is less effective in improving respiratory function. SUMMARY: The current data from human trials does not support the implementation of aerosolized surfactant therapy to treat newborns with RDS. Further research is necessary to improve nebulization, delivery, distribution and deposition in the lung, to investigate aerosolized surfactant delivery via ETT and to determine the appropriate dose. KEYWORDS: surfactant, aerosol, prematurity, respiratory distress syndrome.

Enhanced oil recovery with surfactant flooding

Energy Technology Data Exchange (ETDEWEB)

Buelow Sandersen, S.

2012-05-15

Understanding the underlying mechanisms of systems that exhibit liquid-liquid equilibrium (e.g. oil-brine systems) at reservoir conditions is an area of increasing interest within EOR. This is true both for complex surfactant systems as well as for oil and brine systems. It is widely accepted that an increase in oil recovery can be obtained through flooding, whether it is simple waterflooding, waterflooding where the salinity has been modified by the addition or removal of specific ions (socalled ''smart'' waterflooding) or surfactant flooding. High pressure experiments have been carried out in this work on a surfactant system (surfactant/ oil/ brine) and on oil/ seawater systems (oil/ brine). The high pressure experiments were carried out on a DBR JEFRI PVT cell, where a glass window allows observation of the phase behavior of the different systems at various temperatures and pressures inside the high pressure cell. Phase volumes can also be measured visually through the glass window using precision equipment. The surfactant system for which an experimental study was carried out consisted of the mixture heptane, sodium dodecyl sulfate (SDS)/ 1-butanol/ NaCl/ water. This system has previously been examined at ambient pressures and temperatures but this has been extended here to pressures up to 400 bar and to slightly higher temperatures (40 deg. C, 45 deg. C and 50 deg. C). Experiments were performed at constant salinity (6.56 %), constant surfactant-alcohol ratio (SAR) but with varying water-oil ratios (WOR). At all temperatures it was very clear that the effect of pressure was significant. The system changed from the two phase region, Winsor II, to the three phase region, Winsor III, as pressure increased. Increasing pressures also caused a shift from the three phase region (Winsor III), to a different two phase region, (Winsor I). These changes in equilibrium phase behavior were also dependent on the composition of the system. A number of

Design-based stereological analysis of the lung parenchymal architecture and alveolar type II cells in surfactant protein A and D double deficient mice

DEFF Research Database (Denmark)

Jung, A; Allen, L; Nyengaard, Jens Randel

2005-01-01

Alveolar epithelial type II cells synthesize and secrete surfactant. The surfactant-associated proteins A and D (SP-A and SP-D), members of the collectin protein family, participate in pulmonary immune defense, modulation of inflammation, and surfactant metabolism. Both proteins are known to have......, but the mean volume of a single lamellar body remains constant. These results demonstrate that chronic deficiency of SP-A and SP-D in mice leads to parenchymal remodeling, type II cell hyperplasia and hypertrophy, and disturbed intracellular surfactant metabolism. The design-based stereological approach...

Structure and Conformational Dynamics of DMPC/Dicationic Surfactant and DMPC/Dicationic Surfactant/DNA Systems

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Maciej Kozak

2013-04-01

Full Text Available Amphiphilic dicationic surfactants, known as gemini surfactants, are currently studied for gene delivery purposes. The gemini surfactant molecule is composed of two hydrophilic “head” groups attached to hydrophobic chains and connected via molecular linker between them. The influence of different concentrations of 1,5-bis (1-imidazolilo-3-decyloxymethyl pentane chloride (gemini surfactant on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC bilayers with and without the presence of DNA was investigated using Fourier transformed infrared (FTIR and circular dichroism (CD spectroscopies, small angle scattering of synchrotron radiation and differential scanning calorimetry. With increasing concentration of surfactant in DMPC/DNA systems, a disappearance of pretransition and a decrease in the main phase transition enthalpy and temperature were observed. The increasing intensity of diffraction peaks as a function of surfactant concentration also clearly shows the ability of the surfactant to promote the organisation of lipid bilayers in the multilayer lamellar phase.

Evaporation kinetics of surfactant solution droplets on rice (Oryza sativa) leaves

Science.gov (United States)

Cao, Li-Dong; Zheng, Li; Xu, Jun; Li, Feng-Min; Huang, Qi-Liang

2017-01-01

The dynamics of evaporating sessile droplets on hydrophilic or hydrophobic surfaces is widely studied, and many models for these processes have been developed based on experimental evidence. However, few research has been explored on the evaporation of sessile droplets of surfactant or pesticide solutions on target crop leaves. Thus, in this paper the impact of surfactant concentrations on contact angle, contact diameter, droplet height, and evolution of the droplets’ evaporative volume on rice leaf surfaces have been investigated. The results indicate that the evaporation kinetics of surfactant droplets on rice leaves were influenced by both the surfactant concentrations and the hydrophobicity of rice leaf surfaces. When the surfactant concentration is lower than the surfactant CMC (critical micelle concentration), the droplet evaporation time is much longer than that of the high surfactant concentration. This is due to the longer existence time of a narrow wedge region under the lower surfactant concentration, and such narrow wedge region further restricts the droplet evaporation. Besides, our experimental data are shown to roughly collapse onto theoretical curves based on the model presented by Popov. This study could supply theoretical data on the evaporation of the adjuvant or pesticide droplets for practical applications in agriculture. PMID:28472108

Behavior of gadolinium-based diagnostics in water treatment

Energy Technology Data Exchange (ETDEWEB)

Cyris, Maike

2013-04-25

determined, however, it is strongly assumed that the anthropogenic gadolinium fraction is present as chelate. Adsorption characteristics were evaluated by bottle point isotherm experiments on different activated carbon types and activated polymer based sorbents. The Freundlich coefficients vary between 0.013 and 2.83 (μmol kg{sup -1})(L μmol{sup -1}){sup 1/n} for Gd-BT-DO3A, on Chemviron RD 90 {sup registered} and on the best synthetic adsorbent, respectively. Lab scale experiments with small adsorber columns in a drinking water matrix gave insight in the behavior during fixed-bed adsorption processes. The breakthrough was described successfully by the Linear Driving Force model. Modeling has shown that a description of experimental results is only possible by including dissolved organic carbon isotherm results from drinking water in the model, to describe an additional competitive adsorption effect within the fixed-bed adsorber, different from direct competition. First investigations in a wastewater treatment plant proved a poor adsorption of gadolinium similar to iodinated X-ray contrast media such as iopamidole. Therefore, gadolinium will hardly be removed from wastewater by implementation of a further adsorptive treatment step. However, gadolinium may be utilized as indicator substance for breakthrough. Rate constants of the chelates with ozone and hydroxyl radicals have been determined under pseudo-first-order conditions. Rate constants for the ozone reaction were determined to be < 50 M{sup -1}s{sup -1} for all tested chelates. Hence, the chelates may be considered ozone refractory. For determination of hydroxyl radical rate constants different methods were applied. Radicals were generated either by pulse radiolysis, in this case rate constant were determined directly and by competition with thiocyanate, or by the peroxone process, where only competition kinetics were applied (para-chlorobenzoic acid and tert-butanol as competitors). From pulse radiolysis

Behavior of gadolinium-based diagnostics in water treatment

International Nuclear Information System (INIS)

Cyris, Maike

2013-01-01

, however, it is strongly assumed that the anthropogenic gadolinium fraction is present as chelate. Adsorption characteristics were evaluated by bottle point isotherm experiments on different activated carbon types and activated polymer based sorbents. The Freundlich coefficients vary between 0.013 and 2.83 (μmol kg -1 )(L μmol -1 ) 1/n for Gd-BT-DO3A, on Chemviron RD 90 registered and on the best synthetic adsorbent, respectively. Lab scale experiments with small adsorber columns in a drinking water matrix gave insight in the behavior during fixed-bed adsorption processes. The breakthrough was described successfully by the Linear Driving Force model. Modeling has shown that a description of experimental results is only possible by including dissolved organic carbon isotherm results from drinking water in the model, to describe an additional competitive adsorption effect within the fixed-bed adsorber, different from direct competition. First investigations in a wastewater treatment plant proved a poor adsorption of gadolinium similar to iodinated X-ray contrast media such as iopamidole. Therefore, gadolinium will hardly be removed from wastewater by implementation of a further adsorptive treatment step. However, gadolinium may be utilized as indicator substance for breakthrough. Rate constants of the chelates with ozone and hydroxyl radicals have been determined under pseudo-first-order conditions. Rate constants for the ozone reaction were determined to be < 50 M -1 s -1 for all tested chelates. Hence, the chelates may be considered ozone refractory. For determination of hydroxyl radical rate constants different methods were applied. Radicals were generated either by pulse radiolysis, in this case rate constant were determined directly and by competition with thiocyanate, or by the peroxone process, where only competition kinetics were applied (para-chlorobenzoic acid and tert-butanol as competitors). From pulse radiolysis determinations (rate constants > 10 9 M -1 s -1

Effect of application rates and media types on nitrogen and surfactant removal in trickling filters applied to the post-treatment of effluents from UASB reactors

International Nuclear Information System (INIS)

Almeida, P. G. S. de; Taveres, F. v. F.; Chernicharo, C. A. I.

2009-01-01

Tricking filters are a very promising alternative for the post treatment of effluents from UASB reactors treating domestic sewage,especially in developing countries. Although a fair amount of information is already available regarding organic mater removal in this combined system, very little is known in relation to nitrogen and surfactant removal in trickling filters post-UASB reactors. Therefore, the purpose of this study was to evaluate and compare the effect evaluate and compare the effect of different application rates and packing media types on trickling filters applied to the post-treatment of effluents from UASB reactors, regarding the removal of ammonia nitrogen and surfactants. (Author)

Effect of application rates and media types on nitrogen and surfactant removal in trickling filters applied to the post-treatment of effluents from UASB reactors

Energy Technology Data Exchange (ETDEWEB)

Almeida, P. G. S. de; Taveres, F. v. F.; Chernicharo, C. A. I.

2009-07-01

Tricking filters are a very promising alternative for the post treatment of effluents from UASB reactors treating domestic sewage,especially in developing countries. Although a fair amount of information is already available regarding organic mater removal in this combined system, very little is known in relation to nitrogen and surfactant removal in trickling filters post-UASB reactors. Therefore, the purpose of this study was to evaluate and compare the effect evaluate and compare the effect of different application rates and packing media types on trickling filters applied to the post-treatment of effluents from UASB reactors, regarding the removal of ammonia nitrogen and surfactants. (Author)

Substrate and surfactant effects on the glass-liquid transition of thin water films.

Science.gov (United States)

Souda, Ryutaro

2006-09-07

Temperature-programmed time-of-flight secondary ion mass spectrometry (TP-TOF-SIMS) and temperature-programmed desorption (TPD) have been used to perform a detailed investigation of the adsorption, desorption, and glass-liquid transition of water on the graphite and Ni(111) surfaces in the temperature range 13-200 K. Water wets the graphite surface at 100-120 K, and the hydrogen-bonded network is formed preferentially in the first monolayer to reduce the number of nonbonding hydrogens. The strongly chemisorbed water molecules at the Ni(111) surface do not form such a network and play a role in stabilizing the film morphology up to 160 K, where dewetting occurs abruptly irrespective of the film thickness. The surface structure of the water film formed on graphite is fluctuated considerably, resulting in deweting at 150-160 K depending on the film thickness. The dewetted patches of graphite are molecularly clean, whereas the chemisorbed water remains on the Ni(111) surface even after evaporation of the film. The abrupt drop in the desorption rate of water molecules at 160 K, which has been attributed to crystallization in the previous TPD studies, is found to disappear completely when a monolayer of methanol is present on the surface. This is because the morphology of supercooled liquid water is changed by the surface tension, and it is quenched by termination of the free OH groups on the surface. The surfactant methanol desorbs above 160 K since the hydrogen bonds of the water molecules are reconstructed. The drastic change in the properties of supercooled liquid water at 160 K should be ascribed to the liquid-liquid phase transition.

TECHNOLOGICAL PROCESS ASSESSMENT OF THE DRINKING WATER TREATMENT AT TARGU-MURES WATER TREATMENT PLANT

Directory of Open Access Journals (Sweden)

CORNELIA DIANA HERTIA

2011-03-01

Full Text Available This paper intends to assess the technological process of obtaining drinking water at Targu-Mures water treatment plant. The assessment was performed before changing the technological process and four months were chosen to be analized during 2008: January, April, July and October for its efficiency analysis on treatment steps. Mures River is the water source for the water treatment plant, being characterized by unsteady flow and quality parameters with possible important variability in a very short period of time. The treatment technological process is the classic one, represented by coagulation, sedimentation, filtration and disinfection, but also prechlorination was constantly applied as additional treatment during 2008. Results showed that for the measured parameters, raw water at the water treatment plant fits into class A3 for surface waters, framing dictated by the bacterial load. The treatment processes efficiency is based on the performance calculation for sedimentation, filtration, global and for disinfection, a better conformation degree of technological steps standing out in January in comparison to the other three analyzed months. A variable non-compliance of turbidity and residual chlorine levels in the disinfected water was observed constantly. Previous treatment steps managed to maintain a low level of oxidisability, chlorine consumption and residual chlorine levels being also low. 12% samples were found inconsistent with the national legislation in terms of bacteriological quality. Measures for the water treatment plant retechnologization are taken primarily for hyperchlorination elimination, which currently constitutes a discomfort factor (taste, smell, and a generating factor of chlorination by-products.

Biological treatment of drinking water by chitosan based ...

African Journals Online (AJOL)

ABI

2015-03-18

Mar 18, 2015 ... method. A membrane filtration technique is used for the treatment of water to remove or kill ... The characterization of synthesized nanoparticles was done by dynamic ... water and just 3% is available for drinking, agriculture,.

[Determination of Trace Lead in Water by UV-Visible Diffuse Reflectance Spectroscopy Combined with Surfactant and Membrane Filtration-Enrichment].

Science.gov (United States)

Zhang, Xiao-fang; Zhu, Bi-lin; Li, Wei; Wang, Lei; Zhang, Lei; Wu, Ting; Du, Yi-ping

2015-07-01

In this paper, a method of determination of trace lead in water by UV-Visible diffuse reflectance spectroscopy combined with surfactant and membrane filtration enrichment was proposed. In the NH3 x H2O-NH4Cl buffer solution with pH 8.5, the lead(II) ion would react with dithizone to form the red complex under vigorous stirring, which is hydrophobic and can be enriched by the mixed cellulose ester membrane. In addition, the nonionic surfactant Polyoxyethylene lauryl ether (Brij-30) was added into the solution to improve the enrichment efficiency, then visible diffuse reflectance spectra of the membrane were measured directly after the membrane were naturally dried. We also optimized the reaction conditions which may affect the complexation reaction process, such as type of surfactants, the concentration of the surfactant, the reaction acidity, the concentration of dithizone as well as the reaction time. The research results show that under the optimum conditions, a good linear correlation between absorbance at 485 nm and concentration of lead in the range of 5.0-100.0 microg x L(-1) was obtained with a squared correlation coefficient (R2) of 0.9906, and the detection limit was estimated accordingly to be 2.88 microg x L(-1). To determine real water sample, the interference from some potential coexisting ions was also studied at the optimal conditions when the concentration of lead (II) ion standard solution was fixed to 20 microg x L(-1). The results indicate that the following ions cannot interfere in the determination of lead with the proposed method: 500 times of the K+, Na+, Ca2+, Mg2+, NH4+, NO3-, Cl-, CH3COO-, SO4(2-); 10 times of the Al3+ (using 10% NaF as a masking reagent to avoid the interference); 10 times of the Fe3+ (using 10% NaF and 10% sodium potassium tartrate as masking reagents); 10 times of Hg2+ or Zn2+ (using 10% NaSCN and 10% potassium sodium tartrate as masking reagents); the same amount of Cd2+, Cu2+. The proposed method was applied to the

Comparison on Promotion Effect of Various Types of Surfactants on HCFC-141b Hydrate Induction Time

Science.gov (United States)

Li, Juan; Sun, Zhigao; Liu, Chenggang; Zhu, Minggui

2018-03-01

Cold storage in air conditioning based on refrigerant hydrate is a new-type energy saving technology to reduce initial investment and running cost of air conditioning equipments and improve system stability. Refrigerant hydrate is generated under critical temperature and pressure condition, while surfactant is an effective medium to promote its phase equilibrium. In this paper, in order to research such promotion effect, different type of surfactants with unique mechanism, SDS, Tween80 and Span80, n-BA were selected to compare the respective impact on HCFC141b hydrate induction time based on temperature curve. Experimental results showed that no obvious change had been discovered when no surfactant was added into pure water system, which coincided with phase equilibrium diagram of HCFC141b. All the four kinds of surfactants had realized promotion effect to various degrees. For each hydration system, a large gap existed between the longest and the shortest induction time in 6 groups of parallel experiments, meaning relatively poor system stability. Under the combined effect of Tween80 (2wt%), Span80 (0.1wt%) and n-BA (0.1wt%), average and the shortest induction time was 20.9min and 17.5min respectively, corresponding to the best promotion effect.

Effects of simulated microgravity on surfactant and water balance of lung in animals with different resistance to stress