Scanning probe microscopy for the analysis of composite Ti/hydrocarbon plasma polymer thin films

Science.gov (United States)

Choukourov, A.; Grinevich, A.; Slavinska, D.; Biederman, H.; Saito, N.; Takai, O.

2008-03-01

Composite Ti/hydrocarbon plasma polymer films with different Ti concentration were deposited on silicon by dc magnetron sputtering of titanium in an atmosphere of argon and hexane. As measured by Kelvin force microscopy and visco-elastic atomic force microscopy, respectively, surface potential and hardness increase with increasing Ti content. Adhesion force to silicon and to fibrinogen molecules was stronger for the Ti-rich films as evaluated from the AFM force-distance curves. Fibrinogen forms a very soft layer on these composites with part of the protein molecules embedded in the outermost region of the plasma polymer. An increase of the surface charge due to fibrinogen adsorption has been observed and attributed to positively charged αC domains of fibrinogen molecule.

Wetting, Solubility and Chemical Characteristics of Plasma-Polymerized 1-Isopropyl-4-Methyl-1,4-Cyclohexadiene Thin Films

Directory of Open Access Journals (Sweden)

Jakaria Ahmad

2014-07-01

Full Text Available Investigations on the wetting, solubility and chemical composition of plasma polymer thin films provide an insight into the feasibility of implementing these polymeric materials in organic electronics, particularly where wet solution processing is involved. In this study, thin films were prepared from 1-isopropyl-4-methyl-1,4-cyclohexadiene (γ-Terpinene using radio frequency (RF plasma polymerization. FTIR showed the polymers to be structurally dissimilar to the original monomer and highly cross-linked, where the loss of original functional groups and the degree of cross-linking increased with deposition power. The polymer surfaces were hydrocarbon-rich, with oxygen present in the form of O–H and C=O functional groups. The oxygen content decreased with deposition power, with films becoming more hydrophobic and, thus, less wettable. The advancing and receding contact angles were investigated, and the water advancing contact angle was found to increase from 63.14° to 73.53° for thin films prepared with an RF power of 10 W to 75 W. The wetting envelopes for the surfaces were constructed to enable the prediction of the surfaces’ wettability for other solvents. The effect of roughness on the wetting behaviour of the films was insignificant. The polymers were determined to resist solubilization in solvents commonly used in the deposition of organic semiconducting layers, including chloroform and chlorobenzene, with higher stability observed in films fabricated at higher RF power.

Autophobicity and layering behavior of thin liquid-crystalline polymer films.

NARCIS (Netherlands)

Wielen, van der M.W.J.; Cohen Stuart, M.A.; Fleer, G.J.

1998-01-01

The stability against breaking-up of thin spin-coated films of liquid-crystalline polymers depends on the film thickness and annealing temperature. This study concerns side-chain liquid-crystalline polymers, based on alternating copolymers of maleic anhydride and mesogenic alkenes. The mesogenic

Ion irradiation as a tool for modifying the surface and optical properties of plasma polymerised thin films

Energy Technology Data Exchange (ETDEWEB)

Grant, Daniel S. [College of Science, Technology and Engineering, James Cook University, Townsville, Queensland 4811 (Australia); Bazaka, Kateryna [College of Science, Technology and Engineering, James Cook University, Townsville, Queensland 4811 (Australia); School of Chemistry, Physics, and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4000 (Australia); Siegele, Rainer [Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234 (Australia); Holt, Stephen A. [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234 (Australia); Jacob, Mohan V., E-mail: Mohan.Jacob@jcu.edu.au [College of Science, Technology and Engineering, James Cook University, Townsville, Queensland 4811 (Australia)

2015-10-01

Radio frequency (R.F.) glow discharge polyterpenol thin films were prepared on silicon wafers and irradiated with I{sup 10+} ions to fluences of 1 × 10{sup 10} and 1 × 10{sup 12} ions/cm{sup 2}. Post-irradiation characterisation of these films indicated the development of well-defined nano-scale ion entry tracks, highlighting prospective applications for ion irradiated polyterpenol thin films in a variety of membrane and nanotube-fabrication functions. Optical characterisation showed the films to be optically transparent within the visible spectrum and revealed an ability to selectively control the thin film refractive index as a function of fluence. This indicates that ion irradiation processing may be employed to produce plasma-polymer waveguides to accommodate a variety of wavelengths. XRR probing of the substrate-thin film interface revealed interfacial roughness values comparable to those obtained for the uncoated substrate’s surface (i.e., both on the order of 5 Å), indicating minimal substrate etching during the plasma deposition process.

Polymer thin film as coating layer to prevent corrosion of metal/metal oxide film

Science.gov (United States)

Sarkar, Suman; Kundu, Sarathi

2018-04-01

Thin film of polymer is used as coating layer and the corrosion of metal/metal oxide layer is studied with the variation of the thickness of the coating layer. The thin layer of polystyrene is fabricated using spin coating method on copper oxide (CuO) film which is deposited on glass substrate using DC magnetron sputtering technique. Thickness of the polystyrene and the CuO layers are determined using X-ray reflectivity (XRR) technique. CuO thin films coated with the polystyrene layer are exposed to acetic acid (2.5 v/v% aqueous CH3COOH solution) environments and are subsequently analyzed using UV-Vis spectroscopy and atomic force microscopy (AFM). Surface morphology of the film before and after interaction with the acidic environment is determined using AFM. Results obtained from the XRR and UV-Vis spectroscopy confirm that the thin film of polystyrene acts as an anticorrosion coating layer and the strength of the coating depends upon the polymer layer thickness at a constant acid concentration.

Temperature- and thickness-dependent elastic moduli of polymer thin films

Directory of Open Access Journals (Sweden)

Ao Zhimin

2011-01-01

Full Text Available Abstract The mechanical properties of polymer ultrathin films are usually different from those of their counterparts in bulk. Understanding the effect of thickness on the mechanical properties of these films is crucial for their applications. However, it is a great challenge to measure their elastic modulus experimentally with in situ heating. In this study, a thermodynamic model for temperature- (T and thickness (h-dependent elastic moduli of polymer thin films Ef(T,h is developed with verification by the reported experimental data on polystyrene (PS thin films. For the PS thin films on a passivated substrate, Ef(T,h decreases with the decreasing film thickness, when h is less than 60 nm at ambient temperature. However, the onset thickness (h*, at which thickness Ef(T,h deviates from the bulk value, can be modulated by T. h* becomes larger at higher T because of the depression of the quenching depth, which determines the thickness of the surface layer δ.

Thin polymer films prepared by plasma immersion ion implantation and deposition

International Nuclear Information System (INIS)

Rangel, Elidiane C.; Silva, Paulo A.F.; Mota, Rogerio P.; Schreiner, Wido H.; Cruz, Nilson C.

2005-01-01

This work describes an investigation of the properties of polymer films prepared by plasma immersion ion implantation and deposition. Films were synthesized from low pressure benzene glow discharges, biasing the samples with 25 kV negative pulses. The total energy deposited in the growing layer was varied tailoring simultaneously pulse frequency and duty cycle. The effect of the pulse characteristics on the chemical composition and mechanical properties of the films was studied by X-ray photoelectron spectroscopy (XPS) and nanoindentation, respectively. Analysis of the deconvoluted C 1s XPS peaks demonstrated that oxygen was incorporated in all the samples. The chemical modifications induced structural reorganization, characterized by chain cross-linking and unsaturation, affecting material properties. Hardness and plastic resistance parameter increased under certain bombardment conditions. An interpretation is proposed in terms of the total energy delivered to the growing layer

Microscopy of thin polymer blend films of polystyrene and poly-n-butyl-methacrylate

International Nuclear Information System (INIS)

Schmitt, T.; Guttmann, P.; Schmahl, G.; Schmidt, O.; Schoenhense, G.; Mueller-Buschbaum, P.; Stamm, M.

2000-01-01

The structure of thin polymer blend films of polystyrene (PS) and poly-n-butyl-methacrylate (PnBMA) was examined with Transmission X-ray Microscopy (TXM), Scanning Force Microscopy (SFM), X-Ray Photoemission Electron Microscopy (X-PEEM) and Optical Microscopy (OM). Thin films were prepared by spin casting of a toluene solution of the polymer mixture onto silicon wafers retaining the native oxide. Depending on blend composition and annealing conditions smooth films with and without holes or films with well pronounced surface features (ribbons or islands) were produced. By TXM measurements a high lateral resolution study of the as cast and the annealed polymer blend samples was performed. The contrast in TXM is due to different absorption of x-radiation of the used polymers and due to variation in thickness. With X-PEEM the lateral distribution of the two polymers near the surface was mapped by employing the characteristic Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of the polymers. The TXM technique is a microscopic method integrating over the total film thickness, whereas the X-PEEM technique is a highly surface sensitive method. TXM and X-PEEM are therefore complementary methods which provide important information on the structure of thin polymer blend films additional to the standard techniques SFM and OM

Plasma polymer films rf sputtered from PTFE under various argon pressures

Czech Academy of Sciences Publication Activity Database

Stelmashuk, Vitaliy; Biederman, H.; Slavinská, D.; Zemek, Josef; Trchová, Miroslava

2005-01-01

Roč. 77, č. 2 (2005), s. 131-137 ISSN 0042-207X R&D Projects: GA MŠk(CZ) OC 527.10; GA MŠk(CZ) OC 527.90 Grant - others:EUREKAΣ2080(XE) OE57 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z20430508 Keywords : RF sputtering * PTFE * fluorcarbon plasma polymers * thin film * teflon * deposition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.909, year: 2005

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

International Nuclear Information System (INIS)

Ribeiro, M A; Ramos, A S; Manfredini, M I; Alves, H A; Ramos, E C T; Honda, R Y; Kostov, K G; Lucena, E F; Mota, R P; Algatti, M A; Kayama, M E

2009-01-01

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm -1 ), C-H (3000-2900cm -1 ), C=O (1730-1650cm -1 ), C-O and C-O-C bonds at 1200-1600cm -1 . The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85 deg. to 22 deg. Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

Science.gov (United States)

Ribeiro, M. A.; Ramos, A. S.; Manfredini, M. I.; Alves, H. A.; Y Honda, R.; Kostov, K. G.; Lucena, E. F.; Ramos, E. C. T.; Mota, R. P.; Algatti, M. A.; Kayama, M. E.

2009-05-01

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm-1), C-H (3000-2900cm-1), C=O (1730-1650cm-1), C-O and C-O-C bonds at 1200-1600cm-1. The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85° to 22°. Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

Polyurethane coating with thin polymer films produced by plasma polymerization of diglyme

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, M A; Ramos, A S; Manfredini, M I; Alves, H A; Ramos, E C T [UNIVAP, Sao Jose dos Campos, SP (Brazil); Honda, R Y; Kostov, K G; Lucena, E F; Mota, R P; Algatti, M A; Kayama, M E, E-mail: rmota@feg.unesp.b [FEG-DFQ-UNESP, Av. Ariberto Pereira da Cunha 333, 12516-410 - Guaratingueta, SP (Brazil)

2009-05-01

Aqueous-based polyurethane dispersions have been widely utilized as lubricants in textile, shoes, automotive, biomaterial and many other industries because they are less aggressive to surrounding environment. In this work thin films with different thickness were deposited on biocompatible polyurethane by plasma polymerization process using diethylene glycol dimethyl ether (Diglyme) as monomer. Molecular structure of the films was analyzed by Fourier Transform Infrared spectroscopy. The spectra exhibited absorption bands of O-H (3500-3200cm{sup -1}), C-H (3000-2900cm{sup -1}), C=O (1730-1650cm{sup -1}), C-O and C-O-C bonds at 1200-1600cm{sup -1}. The samples wettability was evaluated by measurements of contact angle using different liquids such as water, glycerol, poly-ethane and CMC. The polyurethane surface showed hydrophilic behavior after diglyme plasma-deposition with contact angle dropping from 85 deg. to 22 deg. Scanning Electron Microscopy revealed that diglyme films covered uniformly the polyurethane surfaces ensuring to it a biocompatible characteristic.

Dynamics in thin folded polymer films

Science.gov (United States)

Croll, Andrew; Rozairo, Damith

Origami and Kirigami inspired structures depend on a complex interplay between geometry and material properties. While clearly important to the overall function, very little attention has focused on how extreme curvatures and singularities in real materials influence the overall dynamic behaviour of folded structures. In this work we use a set of three polymer thin films in order to closely examine the interaction of material and geometry. Specifically, we use polydimethylsiloxane (PDMS), polystyrene (PS) and polycarbonate (PC) thin films which we subject to loading in several model geometries of varying complexity. Depending on the material, vastly different responses are noted in our experiments; D-cones can annihilate, cut or lead to a crumpling cascade when pushed through a film. Remarkably, order can be generated with additional perturbation. Finally, the role of adhesion in complex folded structures can be addressed. AFOSR under the Young Investigator Program (FA9550-15-1-0168).

Film-thickness dependence of structure formation in ultra-thin polymer blend films

CERN Document Server

Gutmann, J S; Stamm, M

2002-01-01

We investigated the film-thickness dependence of structure formation in ultra-thin polymer blend films prepared from solution. As a model system we used binary blends of statistical poly(styrene-co-p-bromostyrene) copolymers of different degrees of bromination. Ultra-thin-film samples differing in miscibility and film thickness were prepared via spin coating of common toluene solutions onto silicon (100) substrates. The resulting morphologies were investigated with scanning force microscopy, reflectometry and grazing-incidence scattering techniques using both X-rays and neutrons in order to obtain a picture of the sample structure at and below the sample surface. (orig.)

Polymer Thin Film Stabilization.

Science.gov (United States)

Costa, A. C.; Oslanec, R.; Composto, R. J.; Vlcek, P.

1998-03-01

We study the dewetting dynamics of thin polystyrene (PS) films deposited on silicon oxide surfaces using optical (OM) and atomic force (AFM) microscopes. Quantitative analysis of the hole diameter as a function of annealing time at 175^oC shows that blending poly(styrene-block-methyl-methacrylate) (PS-b-PMMA) with PS acts to dramatically slow down the dewetting rate and even stops holes growth before they impinge. AFM studies show that the hole floor is smooth for a pure PS film but contains residual polymer for the blend. At 5% vol., a PS-b-PMMA with high molar mass and low PMMA is a more effective stabilizing agent than a low molar mass/high PMMA additive. The optimum copolymer concentration is 3% vol. beyond which film stability doesn't improve. Although dewetting is slowed down relative to pure PS, PS/PS-b-PMMA bilayers dewet at a faster rate than blends having the same overall additive concentration.

Optical characterizations of silver nanoprisms embedded in polymer thin film layers

Science.gov (United States)

Carlberg, Miriam; Pourcin, Florent; Margeat, Olivier; Le Rouzo, Judikael; Berginc, Gerard; Sauvage, Rose-Marie; Ackermann, Jorg; Escoubas, Ludovic

2017-10-01

The precise control of light-matter interaction has a wide range of applications and is currently driven by the use of nanoparticles (NPs) by the recent advances in nanotechnology. Taking advantage of the material, size, shape, and surrounding media dependence of the optical properties of plasmonic NPs, thin film layers with tunable optical properties are achieved. The NPs are synthesized by wet chemistry and embedded in a polyvinylpyrrolidone (PVP) polymer thin film layer. Spectrophotometer and spectroscopic ellipsometry measurements are coupled to finite-difference time domain numerical modeling to optically characterize the heterogeneous thin film layers. Silver nanoprisms of 10 to 50 nm edge size exhibit high absorption through the visible wavelength range. A simple optical model composed of a Cauchy law and a Lorentz law, accounting for the optical properties of the nonabsorbing polymer and the absorbing property of the nanoprisms, fits the spectroscopic ellipsometry measurements. Knowing the complex optical indices of heterogeneous thin film layers let us design layers of any optical properties.

Influence of film structure on the dewetting kinetics of thin polymer films in the solvent annealing process.

Science.gov (United States)

Zhang, Huanhuan; Xu, Lin; Lai, Yuqing; Shi, Tongfei

2016-06-28

On a non-wetting solid substrate, the solvent annealing process of a thin polymer film includes the swelling process and the dewetting process. Owing to difficulties in the in situ analysis of the two processes simultaneously, a quantitative study on the solvent annealing process of thin polymer films on the non-wetting solid substrate is extremely rare. In this paper, we design an experimental method by combining spectroscopic ellipsometry with optical microscopy to achieve the simultaneous in situ study. Using this method, we investigate the influence of the structure of swollen film on its dewetting kinetics during the solvent annealing process. The results show that for a thin PS film with low Mw (Mw = 4.1 kg mol(-1)), acetone molecules can form an ultrathin enriched layer between the PS film and the solid substrate during the swelling process. The presence of the acetone enriched layer accounts for the exponential kinetic behavior in the case of a thin PS film with low Mw. However, the acetone enriched layer is not observed in the case of a thin PS film with high Mw (Mw = 400 kg mol(-1)) and the slippage effect of polymer chains is valid during the dewetting process.

Properties of a-C:H:O plasma polymer films deposited from acetone vapors

Energy Technology Data Exchange (ETDEWEB)

Drabik, M., E-mail: martin.drabik@gmail.com [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland); Celma, C. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland); Kousal, J.; Biederman, H. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Hegemann, D. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland)

2014-12-31

To gain insight into the deposition and stability of oxygen-containing plasma polymer films, the properties of amorphous oxygenated hydrocarbon (a-C:H:O) plasma polymer coatings deposited from acetone vapors under various experimental conditions are investigated. Apart from the discharge power, the influence of the reactive carbon dioxide (CO{sub 2}) gas on the structure of the resulting films is studied. It is found by characterization using X-ray Photoelectron Spectroscopy and Fourier-Transform Infrared Spectroscopy that the experimental conditions particularly influence the amount of oxygen in the deposited a-C:H:O plasma polymer films. The O/C elemental ratio increases with increasing amount of CO{sub 2} in the working gas mixture (up to 0.2 for 24 sccm of CO{sub 2} at 30 W) and decreases with increasing RF discharge power (down to 0.17 for 50 W). Furthermore, the nature of bonds between the oxygen and carbon atoms has been examined. Only low amounts of double and triple bonded carbon are observed. This has a particular influence on the aging of the plasma polymer films which is studied both in ambient air and in distilled water for up to 4 months. Overall, stable a-C:H:O plasma polymer films are deposited comprising low amounts (up to about 5%) of ester/carboxyl groups. - Highlights: • Hydrocarbon plasma polymer films with variable oxygen content can be prepared. • Stable oxygenated hydrocarbon plasma polymers contain max 5% of ester/carboxyl groups. • Acetone-derived plasma polymer films can be used as permanent hydrophilic surfaces.

Layered double hydroxides/polymer thin films grown by matrix assisted pulsed laser evaporation

Energy Technology Data Exchange (ETDEWEB)

Birjega, R.; Matei, A.; Mitu, B.; Ionita, M.D.; Filipescu, M.; Stokker-Cheregi, F.; Luculescu, C.; Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., 77125 Bucharest–Magurele (Romania); Zavoianu, R.; Pavel, O.D. [University of Bucharest, Faculty of Chemistry, Department of Chemical Technology and Catalysis, 4-12 Regina Elisabeta Bd., Bucharest (Romania); Corobea, M.C. [National R. and S. Institute for Chemistry and Petrochemistry, ICECHIM, 202 Splaiul Independentei Str., CP-35-274, 060021, Bucharest (Romania)

2013-09-30

Due to their highly tunable properties, layered double hydroxides (LDHs) are an emerging class of the favorably layered crystals used for the preparation of multifunctional polymer/layered crystal nanocomposites. In contrast to cationic clay materials with negatively charge layers, LDHs are the only host lattices with positively charged layers (brucite-like), with interlayer exchangeable anions and intercalated water. In this work, the deposition of thin films of Mg and Al based LDH/polymers nanocomposites by laser techniques is reported. Matrix assisted pulsed laser evaporation was the method used for thin films deposition. The Mg–Al LDHs capability to act as a host for polymers and to produce hybrid LDH/polymer films has been investigated. Polyethylene glycol with different molecular mass compositions and ethylene glycol were used as polymers. The structure and surface morphology of the deposited LDH/polymers films were examined by X-ray diffraction, Fourier transform infra-red spectroscopy, atomic force microscopy and scanning electron microscopy. - Highlights: • Hybrid composites deposited by matrix assisted pulsed laser evaporation (MAPLE). • Mg–Al layered double hydroxides (LDH) and polyethylene glycol (PEG) are used. • Mixtures of PEG1450 and LDH were deposited by MAPLE. • Deposited thin films preserve the properties of the starting material. • The film wettability can be controlled by the amount of PEG.

Laser welding of thin polymer films to container substrates for aseptic packaging

Science.gov (United States)

Brown, N.; Kerr, D.; Jackson, M. R.; Parkin, R. M.

2000-03-01

Keyhole laser welding of polymers is a subject well covered and researched, but relatively little information exists regarding the welding of thin polymer films, particularly to a heavier substrate. This paper presents the design of a suitable test apparatus for laser welding thin film to a heavier substrate, and shows the results of an investigation into the feasibility of laser welding multi-layer polymer film lids to tubs for the manufacture of aseptic food containers. A consistent weld, free from defects, is the key to process success. Typical welding defects have been synthesised in order to investigate, and consequently remove, their cause. The result is a reliable welding method based on even film clamping. With careful attention to machine design, a seal of high mechanical strength and chemical integrity is possible.

Aging effects of plasma polymerized ethylenediamine (PPEDA) thin films on cell-adhesive implant coatings

International Nuclear Information System (INIS)

Testrich, H.; Rebl, H.; Finke, B.; Hempel, F.; Nebe, B.; Meichsner, J.

2013-01-01

Thin plasma polymer films from ethylenediamine were deposited on planar substrates placed on the powered electrode of a low pressure capacitively coupled 13.56 MHz discharge. The chemical composition of the plasma polymer films was analyzed by Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) as well as by X-ray photoelectron spectroscopy (XPS) after derivatization of the primary amino groups. The PPEDA films undergo an alteration during the storage in ambient air, particularly, due to reactions with oxygen. The molecular changes in PPEDA films were studied over a long-time period of 360 days. Simultaneously, the adhesion of human osteoblast-like cells MG-63 (ATCC) was investigated on PPEDA coated corundum blasted titanium alloy (Ti-6Al-4V), which is applied as implant material in orthopedic surgery. The cell adhesion was determined by flow cytometry and the cell shape was analyzed by scanning electron microscopy. Compared to uncoated reference samples a significantly enhanced cell adhesion and proliferation were measured for PPEDA coated samples, which have been maintained after long-time storage in ambient air and additional sterilization by γ−irradiation. - Highlights: • Development of cell-adhesive nitrogen-rich coatings for biomedical applications. • Plasma polymer films from low pressure 13.56 MHz discharge in argon-ethylenediamine. • Enhanced osteoblast adhesion/proliferation on coated implant material (Ti-6Al-4V). • Despite film aging over 360 days the enhanced cell adhesion of the coating remains. • No influence of additional y-sterilization on the enhanced cell adhesion

Immobilization and controlled release of drug using plasma polymerized thin film

Energy Technology Data Exchange (ETDEWEB)

Myung, Sung-Woon [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Sunchon 540-742 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of)

2015-06-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release.

Immobilization and controlled release of drug using plasma polymerized thin film

International Nuclear Information System (INIS)

Myung, Sung-Woon; Jung, Sang-Chul; Kim, Byung-Hoon

2015-01-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release

Numerical simulations of electrohydrodynamic evolution of thin polymer films

Science.gov (United States)

Borglum, Joshua Christopher

Recently developed needleless electrospinning and electrolithography are two successful techniques that have been utilized extensively for low-cost, scalable, and continuous nano-fabrication. Rational understanding of the electrohydrodynamic principles underneath these nano-manufacturing methods is crucial to fabrication of continuous nanofibers and patterned thin films. This research project is to formulate robust, high-efficiency finite-difference Fourier spectral methods to simulate the electrohydrodynamic evolution of thin polymer films. Two thin-film models were considered and refined. The first was based on reduced lubrication theory; the second further took into account the effect of solvent drying and dewetting of the substrate. Fast Fourier Transform (FFT) based spectral method was integrated into the finite-difference algorithms for fast, accurately solving the governing nonlinear partial differential equations. The present methods have been used to examine the dependencies of the evolving surface features of the thin films upon the model parameters. The present study can be used for fast, controllable nanofabrication.

A new lithography of functional plasma polymerized thin films

International Nuclear Information System (INIS)

Kim, Sung-O

2001-01-01

The preparation of the resist for the vacuum lithography was carried out by plasma polymerization. The resist manufactured by plasma polymerization is a monomer produced by MMA (Methyl methacrylate). The functional groups of MMA appeared in the PPMMA (Plasma Polymerized Methyl methacrylate) as well, and this was confirmed through an analysis using FT-IR. The polymerization rate increased as a function of the plasma power and decreased as a function of the system pressure. The sensitivity and contrast of the plasma polymerized thin films were 15 μC/cm2 and 4.3 respectively. The size of the pattern manufactured by Vacuum Lithography using the plasma polymerized thin films was 100 nm

The influence of polymer architectures on the dewetting behavior of thin polymer films: from linear chains to ring chains.

Science.gov (United States)

Wang, Lina; Xu, Lin; Liu, Binyuan; Shi, Tongfei; Jiang, Shichun; An, Lijia

2017-05-03

The dewetting behavior of ring polystyrene (RPS) film and linear polystyrene (LPS) film on silanized Si substrates with different grafting densities and PDMS substrate was investigated. Results showed that polymer architectures greatly influenced the dewetting behavior of the thin polymer film. On the silanized Si substrate with 69% grafting density, RPS chains exhibited stronger adsorption compared with LPS chains, and as a result the wetting layer formed more easily. For LPS films, with a decreased annealing temperature, the stability of the polymer film changed from non-slip dewetting via apparent slip dewetting to apparently stable. However, for RPS films, the polymer film stability switched from apparent slip dewetting to apparently stable. On the silanized Si substrate with 94% grafting density, the chain adsorption became weaker and the dewetting processes were faster than that on the substrate with 69% grafting density at the same experimental temperature for both the LPS and RPS films. Moreover, on the PDMS substrate, LPS films always showed non-slip dewetting, while the dewetting kinetics of RPS films switched from non-slip dewetting to slip dewetting behaviour. Forming the wetting layer strongly influenced the stability and dewetting behavior of the thin polymer films.

Direct covalent coupling of proteins to nanostructured plasma polymers: a route to tunable cell adhesion

International Nuclear Information System (INIS)

Melnichuk, Iurii; Choukourov, Andrei; Bilek, Marcela; Weiss, Anthony; Vandrovcová, Marta; Bačáková, Lucie; Hanuš, Jan; Kousal, Jaroslav; Shelemin, Artem; Solař, Pavel

2015-01-01

Highlights: • Flat and nanostructured interfaces were overcoated by hydrocarbon plasma polymer. • Linker-free covalent attachment of proteins to resultant surfaces was validated. • Ultra-thin hydrocarbon overcoat (<2 nm) secured prolonged effective binding. • Pre-adsorbed tropoelastin promoted proliferation of osteoblast-like MG-63 cells. • Nanostructured films were multi-affine and impeded cell adhesion. - Abstract: Flat and nanostructured thin films were fabricated by deposition of ultra-thin (<2 nm) layer of hydrocarbon plasma polymer over polished silicon and over a pattern of 8 nm-thick poly(ethylene) islands on silicon. Linker-free radical-based covalent binding of bovine serum albumin and tropoelastin was confirmed for both types of films. The binding capability of albumin was found to be stable over many days of ambient air storage time. Tropoelastin-mediated flat plasma polymers favored adhesion and proliferation of osteoblast-like MG-63 cells. Nanostructured plasma polymers were multi-affine and their hierarchical surface represented an additional barrier for cell attachment

Heating of polymer substrate by discharge plasma in radiofrequency magnetron sputtering deposition

International Nuclear Information System (INIS)

Sirghi, Lucel; Popa, Gheorghe; Hatanaka, Yoshinori

2006-01-01

The substrate used for the thin film deposition in a radiofrequency magnetron sputtering deposition system is heated by the deposition plasma. This may change drastically the surface properties of the polymer substrates. Deposition of titanium dioxide thin films on polymethyl methacrylate and polycarbonate substrates resulted in buckling of the substrate surfaces. This effect was evaluated by analysis of atomic force microscopy topography images of the deposited films. The amount of energy received by the substrate surface during the film deposition was determined by a thermal probe. Then, the results of the thermal probe measurements were used to compute the surface temperature of the polymer substrate. The computation revealed that the substrate surface temperature depends on the substrate thickness, discharge power and substrate holder temperature. For the case of the TiO 2 film depositions in the radiofrequency magnetron plasma, the computation indicated substrate surface temperature values under the polymer melting temperature. Therefore, the buckling of polymer substrate surface in the deposition plasma may not be regarded as a temperature driven surface instability, but more as an effect of argon ion bombardment

Lattice cluster theory for dense, thin polymer films.

Science.gov (United States)

Freed, Karl F

2015-04-07

While the application of the lattice cluster theory (LCT) to study the miscibility of polymer blends has greatly expanded our understanding of the monomer scale molecular details influencing miscibility, the corresponding theory for inhomogeneous systems has not yet emerged because of considerable technical difficulties and much greater complexity. Here, we present a general formulation enabling the extension of the LCT to describe the thermodynamic properties of dense, thin polymer films using a high dimension, high temperature expansion. Whereas the leading order of the LCT for bulk polymer systems is essentially simple Flory-Huggins theory, the highly non-trivial leading order inhomogeneous LCT (ILCT) for a film with L layers already involves the numerical solution of 3(L - 1) coupled, highly nonlinear equations for the various density profiles in the film. The new theory incorporates the essential "transport" constraints of Helfand and focuses on the strict imposition of excluded volume constraints, appropriate to dense polymer systems, rather than the maintenance of chain connectivity as appropriate for lower densities and as implemented in self-consistent theories of polymer adsorption at interfaces. The ILCT is illustrated by presenting examples of the computed profiles of the density, the parallel and perpendicular bonds, and the chain ends for free standing and supported films as a function of average film density, chain length, temperature, interaction with support, and chain stiffness. The results generally agree with expected general trends.

Lattice cluster theory for dense, thin polymer films

International Nuclear Information System (INIS)

Freed, Karl F.

2015-01-01

While the application of the lattice cluster theory (LCT) to study the miscibility of polymer blends has greatly expanded our understanding of the monomer scale molecular details influencing miscibility, the corresponding theory for inhomogeneous systems has not yet emerged because of considerable technical difficulties and much greater complexity. Here, we present a general formulation enabling the extension of the LCT to describe the thermodynamic properties of dense, thin polymer films using a high dimension, high temperature expansion. Whereas the leading order of the LCT for bulk polymer systems is essentially simple Flory-Huggins theory, the highly non-trivial leading order inhomogeneous LCT (ILCT) for a film with L layers already involves the numerical solution of 3(L − 1) coupled, highly nonlinear equations for the various density profiles in the film. The new theory incorporates the essential “transport” constraints of Helfand and focuses on the strict imposition of excluded volume constraints, appropriate to dense polymer systems, rather than the maintenance of chain connectivity as appropriate for lower densities and as implemented in self-consistent theories of polymer adsorption at interfaces. The ILCT is illustrated by presenting examples of the computed profiles of the density, the parallel and perpendicular bonds, and the chain ends for free standing and supported films as a function of average film density, chain length, temperature, interaction with support, and chain stiffness. The results generally agree with expected general trends

Conductivity behavior of very thin gold films ruptured by mass transport in photosensitive polymer film

Energy Technology Data Exchange (ETDEWEB)

Linde, Felix; Sekhar Yadavalli, Nataraja; Santer, Svetlana [Department of Experimental Physics, Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam (Germany)

2013-12-16

We report on conductivity behavior of very thin gold layer deposited on a photosensitive polymer film. Under irradiation with light interference pattern, the azobenzene containing photosensitive polymer film undergoes deformation at which topography follows a distribution of intensity, resulting in the formation of a surface relief grating. This process is accompanied by a change in the shape of the polymer surface from flat to sinusoidal together with a corresponding increase in surface area. The gold layer placed above deforms along with the polymer and ruptures at a strain of 4%. The rupturing is spatially well defined, occurring at the topographic maxima and minima resulting in periodic cracks across the whole irradiated area. We have shown that this periodic micro-rupturing of a thin metal film has no significant impact on the electrical conductivity of the films. We suggest a model to explain this phenomenon and support this by additional experiments where the conductivity is measured in a process when a single nanoscopic scratch is formed with an AFM tip. Our results indicate that in flexible electronic materials consisting of a polymer support and an integrated metal circuit, nano- and micro cracks do not alter significantly the behavior of the conductivity unless the metal is disrupted completely.

Confinement Effects on Host Chain Dynamics in Polymer Nanocomposite Thin Films

Energy Technology Data Exchange (ETDEWEB)

Johnson, Kyle J. [Department; Glynos, Emmanouil [Department; Maroulas, Serafeim-Dionysios [Department; Narayanan, Suresh [Advanced; Sakellariou, Georgios [Department; Green, Peter F. [Department; National

2017-09-07

Incorporating nanoparticles (NPs) within a polymer host to create polymer nanocomposites (PNCs) while having the effect of increasing the functionality (e.g., sensing, energy conversion) of these materials influences other properties. One challenge is to understand the effects of nanoparticles on the viscosity of nanoscale thick polymer films. A new mechanism that contributes to an enhancement of the viscosity of nanoscale thick polymer/nanoparticle films is identified. We show that while the viscosities of neat homopolymer poly(2-vinylpyridine) (P2VP) films as thin as 50 nm remained the same as the bulk, polymer/nanoparticle films containing P2VP brush-coated gold NPs, spaced 50 nm apart, exhibited unprecedented increases in viscosities of over an order of magnitude. For thicker films or more widely separated NPs, the chain dynamics and viscosities were comparable to the bulk values. These results - NP proximities and suppression of their dynamics - suggest a new mechanism by which the viscosities of polymeric liquids could be controlled for nanoscale applications.

Atmospheric Pressure Plasma Jet-Assisted Synthesis of Zeolite-Based Low-k Thin Films.

Science.gov (United States)

Huang, Kai-Yu; Chi, Heng-Yu; Kao, Peng-Kai; Huang, Fei-Hung; Jian, Qi-Ming; Cheng, I-Chun; Lee, Wen-Ya; Hsu, Cheng-Che; Kang, Dun-Yen

2018-01-10

Zeolites are ideal low-dielectric constant (low-k) materials. This paper reports on a novel plasma-assisted approach to the synthesis of low-k thin films comprising pure-silica zeolite MFI. The proposed method involves treating the aged solution using an atmospheric pressure plasma jet (APPJ). The high reactivity of the resulting nitrogen plasma helps to produce zeolite crystals with high crystallinity and uniform crystal size distribution. The APPJ treatment also remarkably reduces the time for hydrothermal reaction. The zeolite MFI suspensions synthesized with the APPJ treatment are used for the wet deposition to form thin films. The deposited zeolite thin films possessed dense morphology and high crystallinity, which overcome the trade-off between crystallinity and film quality. Zeolite thin films synthesized using the proposed APPJ treatment achieve low leakage current (on the order of 10 -8 A/cm 2 ) and high Young's modulus (12 GPa), outperforming the control sample synthesized without plasma treatment. The dielectric constant of our zeolite thin films was as low as 1.41. The overall performance of the low-k thin films synthesized with the APPJ treatment far exceed existing low-k films comprising pure-silica MFI.

Crystal structure and thin film morphology of BBL ladder polymer

Energy Technology Data Exchange (ETDEWEB)

Song, H H [Department of Macromolecular Science, Han Nam University, Taejon (Korea, Republic of); Fratini, A V [Department of Chemistry, University of Dayton, Dayton, OH (United States); Chabinyc, M [Department of Chemistry, University of Dayton, Dayton, OH (United States); Price, G E [University of Dayton Research, Dayton, OH (United States); Agrawal, A K [Systran Corporation, Dayton, OH (United States); Wang, C S [University of Dayton Research, Dayton, OH (United States); Burkette, J [University of Dayton Research, Dayton, OH (United States); Dudis, D S [Materials Directorate, Wright Laboratory, Wright-Patterson Air Force Base, OH (United States); Arnold, F E [Materials Directorate, Wright Laboratory, Wright-Patterson Air Force Base, OH (United States)

1995-03-01

Crystal structure and morphology of poly[7-oxo-7H-benz(d,e)imidazo(4`,5`:5,6)-benzimidazo(2,1-a)isoquinoline-3,4:10,11-tetrayl-10-carbonyl] (BBL) ladder-like polymer were studied. The polymer forms a two-dimensional lattice of nematic liquid crystalline structure. An orthorhombic unit cell with cell parameters of a=7.87 b=3.37 c=11.97A was determined from the fiber diffraction pattern. In thin films, the rigid chains spontaneously form a layered structure across the film thickness, but in a very unusual manner, i.e. the very large molecular plane is standing perpendicularly to the film surface plane. The results are identical to our recent results of poly(p-phenylene benzobisthiazole) (PBT) film [7]. The polymer, however, lost its anisotropic order upon extrusion into a film and resulted in a fiber-like structure. (orig.)

Solution precursor plasma deposition of nanostructured CdS thin films

International Nuclear Information System (INIS)

Tummala, Raghavender; Guduru, Ramesh K.; Mohanty, Pravansu S.

2012-01-01

Highlights: ► Inexpensive process with capability to produce large scale nanostructured coatings. ► Technique can be employed to spray the coatings on any kind of substrates including polymers. ► The CdS coatings developed have good electrical conductivity and optical properties. ► Coatings possess large amount of particulate boundaries and nanostructured grains. -- Abstract: Cadmium sulfide (CdS) films are used in solar cells, sensors and microelectronics. A variety of techniques, such as vapor based techniques, wet chemical methods and spray pyrolysis are frequently employed to develop adherent CdS films. In the present study, rapid deposition of CdS thin films via plasma spray route using a solution precursor was investigated, for the first time. Solution precursor comprising cadmium chloride, thiourea and distilled water was fed into a DC plasma jet via an axial atomizer to create ultrafine droplets for instantaneous and accelerated thermal decomposition in the plasma plume. The resulting molten/semi-molten ultrafine/nanoparticles of CdS eventually propel toward the substrate to form continuous CdS films. The chemistry of the solution precursor was found to be critical in plasma pyrolysis to control the stoichiometry and composition of the films. X-ray diffraction studies confirmed hexagonal α-CdS structure. Surface morphology and microstructures were investigated to compare with other synthesis techniques in terms of process mechanism and structural features. Transmission electron microscopy studies revealed nanostructures in the atomized particulates. Optical measurements indicated a decreasing transmittance in the visible light with increasing the film thickness and band gap was calculated to be ∼2.5 eV. The electrical resistivity of the films (0.243 ± 0.188 × 10 5 Ω cm) was comparable with the literature values. These nanostructured polycrystalline CdS films could be useful in sensing and solar applications.

Solution precursor plasma deposition of nanostructured CdS thin films

Energy Technology Data Exchange (ETDEWEB)

Tummala, Raghavender [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States); Guduru, Ramesh K., E-mail: rkguduru@umich.edu [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States); Mohanty, Pravansu S. [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States)

2012-03-15

Highlights: Black-Right-Pointing-Pointer Inexpensive process with capability to produce large scale nanostructured coatings. Black-Right-Pointing-Pointer Technique can be employed to spray the coatings on any kind of substrates including polymers. Black-Right-Pointing-Pointer The CdS coatings developed have good electrical conductivity and optical properties. Black-Right-Pointing-Pointer Coatings possess large amount of particulate boundaries and nanostructured grains. -- Abstract: Cadmium sulfide (CdS) films are used in solar cells, sensors and microelectronics. A variety of techniques, such as vapor based techniques, wet chemical methods and spray pyrolysis are frequently employed to develop adherent CdS films. In the present study, rapid deposition of CdS thin films via plasma spray route using a solution precursor was investigated, for the first time. Solution precursor comprising cadmium chloride, thiourea and distilled water was fed into a DC plasma jet via an axial atomizer to create ultrafine droplets for instantaneous and accelerated thermal decomposition in the plasma plume. The resulting molten/semi-molten ultrafine/nanoparticles of CdS eventually propel toward the substrate to form continuous CdS films. The chemistry of the solution precursor was found to be critical in plasma pyrolysis to control the stoichiometry and composition of the films. X-ray diffraction studies confirmed hexagonal {alpha}-CdS structure. Surface morphology and microstructures were investigated to compare with other synthesis techniques in terms of process mechanism and structural features. Transmission electron microscopy studies revealed nanostructures in the atomized particulates. Optical measurements indicated a decreasing transmittance in the visible light with increasing the film thickness and band gap was calculated to be {approx}2.5 eV. The electrical resistivity of the films (0.243 {+-} 0.188 Multiplication-Sign 10{sup 5} {Omega} cm) was comparable with the literature

The optical properties of plasma polymerized polyaniline thin films

Energy Technology Data Exchange (ETDEWEB)

Goktas, Hilal, E-mail: hilal_goktas@yahoo.com [Canakkale Onsekiz Mart University, Physics Department, 17020 Canakkale (Turkey); Demircioglu, Zahide; Sel, Kivanc [Canakkale Onsekiz Mart University, Physics Department, 17020 Canakkale (Turkey); Gunes, Taylan [Yalova University, Energy Systems Engineering Department, 77100 Yalova (Turkey); Kaya, Ismet [Canakkale Onsekiz Mart University, Chemistry Department, 17020 Canakkale (Turkey)

2013-12-02

We report herein the characterizations of polyaniline thin films synthesized using double discharge plasma system. Quartz glass substrates were coated at a pressure of 80 Pa, 19.0 kV pulsed and 1.5 kV dc potential. The substrates were located at different regions in the reactor to evaluate the influence of the position on the morphological and molecular structure of the obtained thin films. The molecular structure of the thin films was investigated by Fourier transform infrared (FTIR) and UV–visible photospectrometers (UV–vis), and the morphological studies were carried out by scanning electron microscope. The FTIR and UV–vis data revealed that the molecular structures of the synthesized thin films were in the form of leuocoemeraldine and exhibited similar structures with the films produced via chemical or electrochemical methods. The optical energy band gap values of the as-grown samples ranged from 2.5 to 3.1 eV, which indicated that these materials have potential applications in semiconductor devices. The refractive index in the transparent region (from 650 to 1000 nm) steadily decreased from 1.9 to 1.4 and the extinction coefficient was found to be on order of 10{sup −4}. The synthesized thin films showed various degrees of granular morphologies depending on the location of the substrate in the reactor. - Highlights: • Polyaniline thin films were synthesized for the first time via double discharge plasma system. • The films have similar structure to that of the chemically synthesized films. • The morphology of the films could be tuned by this technique. • These materials would have potential applications at semiconductor devices.

TiO2 thin-films on polymer substrates and their photocatalytic activity

International Nuclear Information System (INIS)

Yang, Jae-Hun; Han, Yang-Su; Choy, Jin-Ho

2006-01-01

We have developed dip-coating process for TiO 2 -thin film on polymer substrates (acrylonitrile-butadiene-styrene polymer: ABS, polystyrene: PS). At first, a monodispersed and transparent TiO 2 nano-sol solution was prepared by the controlled hydrolysis of titanium iso-propoxide in the presence of acetylacetone and nitric acid catalyst at 80 deg. C. Powder X-ray diffraction patterns of the dried particles are indicative of crystalline TiO 2 with anatase-type structure. According to the XRD and transmission electron microscopy (TEM) studies, the mean particle size was estimated to be ca. 5 nm. The transparent thin films on ABS and PS substrates were fabricated by dip-coating process by changing the processing variables, such as the number of dip-coating and TiO 2 concentration in nano-sol solution. Scanning electron microscopic (SEM) analysis for the thin film samples reveals that the acetylacetone-modified TiO 2 nano-sol particles are effective for enhancing the interfacial adherence between films and polymeric substrates compared to the unmodified one. Photocatalytic degradation of methylene blue (MB) on the TiO 2 thin-films has also been systematically investigated

Deposition of Polymer Thin Films on ZnO Nanoparticles by a Plasma Treatment

Science.gov (United States)

2001-11-01

exchange for removing metal ions frori water. If on the surface of these nanoparticles, an extremely thin layer of polyacrylic filr can be coated by a...plasma treatment. The polyacrylic film will react with metallic ions in water. As a result of the high surface-to-volume ratio of these narioparticles, the...experiments performed on a JEM 2010F. In FFIR experiment, potassium bromide(KBr) of 99%+ purity was obtained from Aldrich Chemical Company Inc

Mechanical stability of titanium and plasma polymer nanoclusters in nanocomposite coatings

Energy Technology Data Exchange (ETDEWEB)

Palesch, E. [Institute of Materials Chemistry, Brno University of Technology, Brno (Czech Republic); Marek, A. [HVM Plasma, spol. s r.o., Prague (Czech Republic); Solar, P.; Kylian, O. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Vyskocil, J. [HVM Plasma, spol. s r.o., Prague (Czech Republic); Biederman, H. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Cech, V., E-mail: cech@fch.vutbr.cz [Institute of Materials Chemistry, Brno University of Technology, Brno (Czech Republic)

2013-10-01

The mechanical stability of nanoclusters embedded in nanocomposite coatings was investigated by scratch and wear tests supported by atomic force microscopy using surface topography mode. Titanium and plasma polymer nanoclusters were deposited on planar substrates (glass, titanium) using a magnetron-based gas aggregation cluster source. The deposited clusters were overcoated with a thin titanium film of different thicknesses to stabilize the position of the clusters in the nanocomposite coating. Nanotribological measurements were carried out to optimize the thickness of the overcoating film for sufficient interfacial adhesion of the cluster/film system. - Highlights: ► Titanium and plasma polymer nanoclusters were overcoated with thin titanium film. ► The mechanical stability of nanoclusters was characterized by nanotribological tests. ► The film thickness was optimized to stabilize the position of the clusters in coating.

Analysis of annealed thin polymer films prepared from dichloro(methyl)phenylsilane by plasma polymerization

Czech Academy of Sciences Publication Activity Database

Cech, V.; Horvath, P.; Trchová, M.; Zemek, Josef; Matějková, Jiřina

2001-01-01

Roč. 82, - (2001), s. 2106-2112 ISSN 0021-8995 R&D Projects: GA ČR GV106/98/K013; GA ČR GA104/00/0708 Institutional research plan: CEZ:AV0Z1010914 Keywords : plasma polymerization * thin films * thermogravimetric analysis ( TSA ) * FTIR * ESCA/XPS Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.992, year: 2001

Slippage and nanorheology of thin liquid polymer films

International Nuclear Information System (INIS)

Bäumchen, Oliver; Fetzer, Renate; Klos, Mischa; Lessel, Matthias; Marquant, Ludovic; Hähl, Hendrik; Jacobs, Karin

2012-01-01

Thin liquid films on surfaces are part of our everyday life; they serve, e.g., as coatings or lubricants. The stability of a thin layer is governed by interfacial forces, described by the effective interface potential, and has been subject of many studies in recent decades. In recent years, the dynamics of thin liquid films has come into focus since results on the reduction of the glass transition temperature raised new questions on the behavior of especially polymeric liquids in confined geometries. The new focus was fired by theoretical models that proposed significant implication of the boundary condition at the solid/liquid interface on the dynamics of dewetting and the form of a liquid front. Our study reflects these recent developments and adds new experimental data to corroborate the theoretical models. To probe the solid/liquid boundary condition experimentally, different methods are possible, each bearing advantages and disadvantages, which will be discussed. Studying liquid flow on a variety of different substrates entails a view on the direct implications of the substrate. The experimental focus of this study is the variation of the polymer chain length; the results demonstrate that inter-chain entanglements and in particular their density close to the interface, originating from non-bulk conformations, govern the liquid slip of a polymer. (paper)

Second harmonic generation from corona-poled polymer thin films ...

Indian Academy of Sciences (India)

2014-02-09

Feb 9, 2014 ... thin films of Y-shape chromophore with different isolation groups. MUKESH P JOSHI1 ... Pramana – J. Phys., Vol. 82, No. ... C. The main advantage of the Y shape is the stability similar to linear polymer and a processing ability ...

Mechanical comparison of a polymer nanocomposite to a ceramic thin-film anti-reflective filter

International Nuclear Information System (INIS)

Druffel, Thad; Geng Kebin; Grulke, Eric

2006-01-01

Thin-film filters on optical components have been in use for decades and, for those industries utilizing a polymer substrate, the mismatch in mechanical behaviour has caused problems. Surface damage including scratches and cracks induces haze on the optical filter, reducing the transmission of the optical article. An in-mold anti-reflective (AR) filter incorporating 1/4-wavelength thin films based on a polymer nanocomposite is outlined here and compared with a traditional vacuum deposition AR coating. Nanoindentation and nanoscratch techniques are used to evaluate the mechanical properties of the thin films. Scanning electron microscopy (SEM) images of the resulting indentations and scratches are then compared to the force deflection curves to further explain the phenomena. The traditional coatings fractured by brittle mechanisms during testing, increasing the area of failure, whereas the polymer nanocomposite gave ductile failure with less surface damage

Mechanical comparison of a polymer nanocomposite to a ceramic thin-film anti-reflective filter.

Science.gov (United States)

Druffel, Thad; Geng, Kebin; Grulke, Eric

2006-07-28

Thin-film filters on optical components have been in use for decades and, for those industries utilizing a polymer substrate, the mismatch in mechanical behaviour has caused problems. Surface damage including scratches and cracks induces haze on the optical filter, reducing the transmission of the optical article. An in-mold anti-reflective (AR) filter incorporating 1/4-wavelength thin films based on a polymer nanocomposite is outlined here and compared with a traditional vacuum deposition AR coating. Nanoindentation and nanoscratch techniques are used to evaluate the mechanical properties of the thin films. Scanning electron microscopy (SEM) images of the resulting indentations and scratches are then compared to the force deflection curves to further explain the phenomena. The traditional coatings fractured by brittle mechanisms during testing, increasing the area of failure, whereas the polymer nanocomposite gave ductile failure with less surface damage.

Quantum effects on propagation of bulk and surface waves in a thin quantum plasma film

International Nuclear Information System (INIS)

Moradi, Afshin

2015-01-01

The propagation of bulk and surface plasma waves in a thin quantum plasma film is investigated, taking into account the quantum effects. The generalized bulk and surface plasma dispersion relation due to quantum effects is derived, using the quantum hydrodynamic dielectric function and applying appropriate additional boundary conditions. The quantum mechanical and film geometric effects on the bulk and surface modes are discussed. It is found that quantum effects become important for a thin film of small thickness. - Highlights: • New bulk and surface plasma dispersion relations due to quantum effects are derived, in a thin quantum plasma film. • It is found that quantum effects become important for a thin quantum film of small thickness

Structuring of thin-film polymer mixtures upon solvent evaporation

NARCIS (Netherlands)

Schaefer, C.; Michels, J.J.; van der Schoot, P.P.A.M.

2016-01-01

We theoretically study the impact of solvent evaporation on the dynamics of isothermal phase separation of ternary polymer solutions in thin films. In the early stages we obtain a spinodal length scale that decreases with time under the influence of ongoing evaporation. After that rapid demixing

Structuring of Thin-Film Polymer Mixtures upon Solvent Evaporation

NARCIS (Netherlands)

Schaefer, C.; Michels, J. J.; van der Schoot, P.

2016-01-01

We theoretically study the impact of solvent evaporation on the dynamics of isothermal phase separation of ternary polymer solutions in thin films. In the early stages we obtain a spinodal length scale that decreases with time under the influence of ongoing evaporation. After that rapid demixing

Preparation of Pb(Zr, Ti)O3 Thin Films by Plasma-Assisted Sputtering

Science.gov (United States)

Hioki, Tsuyoshi; Akiyama, Masahiko; Ueda, Tomomasa; Onozuka, Yutaka; Suzuki, Kouji

1999-09-01

A novel plasma-assisted RF magnetron sputtering system with an immersed coil antenna between a target and a substrate was applied for preparing Pb(Zr, Ti)O3 (PZT) thin films. The antenna enabled the generation of inductively coupled plasma (ICP) independently of the target RF source. The plasma assisted by the antenna resulted in the changes of ion fluxes and these energy distributions irradiating to the substrate. The crystalline phase of the deposited PZT thin films was occupied by the perovskite phase depending on the antenna power. In addition, a high deposition rate, modified uniformity of film thickness, and a dense film structure with large columnar grains were obtained as a result of effects of the assisted plasma. The application of the plasma-assisted sputtering method may enable the preparation of PZT thin films that haveexcellent properties.

AC plasma induced modifications in Sb{sub 2}S{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Calixto-Rodriguez, M; Martinez, H [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210, Cuernavaca, Morelos (Mexico); Castillo, F [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Mexico D. F. (Mexico); Pena, Y [Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Quimicas, Pedro de Alba s/n, Cd. Universitaria, San Nicolas de los Garza, N.L (Mexico); Sanchez-Juarez, A, E-mail: ciro@nucleares.unam.m [Centro de Investigacion en EnergIa, Universidad Nacional Autonoma de Mexico, Privada Xochicalco s/n Col. Centro, Temixco, Morelos, C.P. 62580 (Mexico)

2010-01-01

Sb{sub 2}S{sub 3} thin films, deposited by the chemical bath deposition method, were treated with N{sub 2} plasma at 3.0 Torr during several minutes. The as-prepared Sb{sub 2}S{sub 3} thin films and films treated with N{sub 2} plasma have been characterized using several techniques. X-ray diffraction studies have shown that plasma treatment induced recrystallization on the as-prepared Sb{sub 2}S{sub 3}thin films. The band gap values decreased from 2.37 to 1.82 eV after plasma treatment, and the electrical conductivity increased from 10{sup 9} to 10{sup 7} ({Omega}cm){sup -1} due to the annealing effect.

Experimental study of the plasma fluorination of Y-Ba-Cu-O thin films

CERN Document Server

Li Qi; Ji Zheng Ming; Feng Yi Jun; Kang Lin; Yang Sen Zu; Wu Pei Heng; Wang Xiao Shu; Ye Yuda

2002-01-01

The authors have experimentally studied the surface modifications of Y-Ba-Cu-O (YBCO) thin films using CF sub 4 plasma. The intensity of the plasma fluorination was controlled by changing the biasing voltage and the time of the plasma treatment. Microstructural analyses reveal that the oxygen content of the YBCO thin films was changed. Transport measurements of sufficient fluorinated YBCO films imply that the films changed totally into an oxygen-deficient semi-conducting state. From these experimental results, the authors believe that plasma fluorination is quite a useful method to form controllable a thin barrier layer in fabricating interface engineered junctions and to form a stable narrow weak-link region in fabricating planar superconductor-normal-superconductor junctions

Functional patterned coatings by thin polymer film dewetting.

Science.gov (United States)

Telford, Andrew M; Thickett, Stuart C; Neto, Chiara

2017-12-01

An approach for the fabrication of functional polymer surface coatings is introduced, where micro-scale structure and surface functionality are obtained by means of self-assembly mechanisms. We illustrate two main applications of micro-patterned polymer surfaces obtained through dewetting of bilayers of thin polymer films. By tuning the physical and chemical properties of the polymer bilayers, micro-patterned surface coatings could be produced that have applications both for the selective attachment and patterning of proteins and cells, with potential applications as biomaterials, and for the collection of water from the atmosphere. In all cases, the aim is to achieve functional coatings using approaches that are simple to realize, use low cost materials and are potentially scalable. Copyright © 2017 Elsevier Inc. All rights reserved.

Properties of nanostructured undoped ZrO{sub 2} thin film electrolytes by plasma enhanced atomic layer deposition for thin film solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Cho, Gu Young; Noh, Seungtak; Lee, Yoon Ho; Cha, Suk Won, E-mail: ybkim@hanyang.ac.kr, E-mail: swcha@snu.ac.kr [Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Ji, Sanghoon [Graduate School of Convergence Science and Technology, Seoul National University, Iui-dong, Yeongtong-gu, Suwon 443-270 (Korea, Republic of); Hong, Soon Wook; Koo, Bongjun; Kim, Young-Beom, E-mail: ybkim@hanyang.ac.kr, E-mail: swcha@snu.ac.kr [Department of Mechanical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); An, Jihwan [Manufacturing Systems and Design Engineering Programme, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 139-743 (Korea, Republic of)

2016-01-15

Nanostructured ZrO{sub 2} thin films were prepared by thermal atomic layer deposition (ALD) and by plasma-enhanced atomic layer deposition (PEALD). The effects of the deposition conditions of temperature, reactant, plasma power, and duration upon the physical and chemical properties of ZrO{sub 2} films were investigated. The ZrO{sub 2} films by PEALD were polycrystalline and had low contamination, rough surfaces, and relatively large grains. Increasing the plasma power and duration led to a clear polycrystalline structure with relatively large grains due to the additional energy imparted by the plasma. After characterization, the films were incorporated as electrolytes in thin film solid oxide fuel cells, and the performance was measured at 500 °C. Despite similar structure and cathode morphology of the cells studied, the thin film solid oxide fuel cell with the ZrO{sub 2} thin film electrolyte by the thermal ALD at 250 °C exhibited the highest power density (38 mW/cm{sup 2}) because of the lowest average grain size at cathode/electrolyte interface.

Morphological, elemental, and optical characterization of plasma polymerized n-butyl methacrylate thin films

Science.gov (United States)

Nasrin, Rahima; Hossain, Khandker S.; Bhuiyan, A. H.

2018-05-01

Plasma polymerized n-butyl methacrylate (PPnBMA) thin films of varying thicknesses were prepared at room temperature by AC plasma polymerization system using a capacitively coupled parallel plate reactor. Field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy-dispersive X-ray (EDX) analysis, and ultraviolet-visible (UV-Vis) spectroscopic investigation have been performed to study the morphological, elemental, and optical properties of the PPnBMA thin films, respectively. The flat and defect-free nature of thin films were confirmed by FESEM and AFM images. With declining plasma power, average roughness and root mean square roughness increase. Allowed direct transition ( E gd) and indirect transition ( E gi) energy gaps were found to be 3.64-3.80 and 3.38-3.45 eV, respectively, for PPnBMA thin films of different thicknesses. Values of E gd as well as E gi increase with the increase of thickness. The extinction coefficient, Urbach energy, and steepness parameter were also determined for these thin films.

Modifications in SnS thin films by plasma treatments

Energy Technology Data Exchange (ETDEWEB)

Martinez, H., E-mail: hm@fis.unam.mx [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico); Avellaneda, D. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico)

2012-02-01

The present study shows the modifications of structural, optical and electrical characteristics that occur in tin sulfide (SnS) thin films treated in air and in nitrogen plasma at different pressure conditions. The films were obtained by the chemical bath deposition method, which results in SnS thin films with an orthorhombic crystalline structure, band gap (E{sub g}) of 1.1-1.2 eV, and electrical conductivities ({sigma}) in the order of 10{sup -6} {Omega}{sup -1}cm{sup -1}. The films treated with air plasma at pressures between 1 and 4 Torr, showed the presence of SnS{sub 2}, Sn{sub 2}S{sub 3}, and SnO{sub 2} phases, within the band gap values ranging from 0.9 to 1.5 eV. On the other hand, the films treated with nitrogen plasma presented the same phases, but showed a significant modification in the electrical conductivity, increasing from 10{sup -6} {Omega}{sup -1}cm{sup -1} (as-deposited) up to 10{sup -2}-10{sup -3} {Omega}{sup -1}cm{sup -1} (plasma treated). This result is a suitable range of conductivity for the improvement of the solar cells with SnS as an absorber material. Also, emission spectroscopy measurements were carried out in both air and nitrogen plasma treatments.

Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

Science.gov (United States)

Jarad, Amer N.; Ibrahim, Kamarulazizi; Ahmed, Nasser M.

2016-07-01

In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10-5 (Ω.cm)-1, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

Energy Technology Data Exchange (ETDEWEB)

Jarad, Amer N., E-mail: amer78malay@yahoo.com.my; Ibrahim, Kamarulazizi, E-mail: kamarul@usm.my; Ahmed, Nasser M., E-mail: nas-tiji@yahoo.com [Nano-optoelectronic Research and Technology Laboratory School of physics, University of Sains Malaysia, 11800 Pulau Pinang (Malaysia)

2016-07-06

In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10{sup −5} (Ω.cm){sup −1}, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

Plasma deposition of organosilicon polymer thin films with embedded nanosilver for prevention of microbial adhesion

International Nuclear Information System (INIS)

Saulou, Claire; Despax, Bernard; Raynaud, Patrice; Zanna, Sandrine; Marcus, Philippe; Mercier-Bonin, Muriel

2009-01-01

Composite thin films (∼170 nm) containing silver nanoclusters embedded in an organosilicon matrix were deposited by PE-CVD onto stainless steel in order to prevent microbial adhesion. The process originality relies on a dual strategy combining silver sputtering and simultaneous plasma polymerization in argon-hexamethyldisiloxane (HMDSO) plasma, using an asymmetrical RF glow discharge. The metal content in the film was controlled by varying the HMDSO flow rate. Investigation of the physico-chemical properties of the obtained films was conducted by X-ray photoelectron spectroscopy and transmission FTIR spectroscopy. Plasma-mediated coatings were composed of C, O, Si and Ag which was predominantly under metallic form, as indicated by XPS analysis. The presence of Si-H, Si-O-Si, Si-(CH) n -Si and C-H groups was established by FTIR. The yeast Saccharomyces cerevisiae was selected as the model for eukaryotic microorganisms. The maximal anti-adhesive efficiency was achieved for the organosilicon matrix alone. When nanosilver was incorporated into the organic matrix, the efficiency was reduced, especially for high metal contents. Silver antimicrobial property was assumed to be related to Ag + progressive release from the embedded nanoparticles into the surrounding medium. This release was confirmed by ICP-MS measurements. Moreover, silver-containing film antifungal activity was observed towards sessile cells.

Plasma deposition of organosilicon polymer thin films with embedded nanosilver for prevention of microbial adhesion

Energy Technology Data Exchange (ETDEWEB)

Saulou, Claire [Universite de Toulouse, INSA, UPS, INPT, LISBP, 135 Av. de Rangueil, F-31077 Toulouse (France); Universite de Toulouse, UPS, INPT, LAPLACE, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Despax, Bernard; Raynaud, Patrice [Universite de Toulouse, UPS, INPT, LAPLACE, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France); Zanna, Sandrine; Marcus, Philippe [LPCS, UMR CNRS/ENSCP 7045, 11 rue P. et M. Curie, 75005 Paris (France); Mercier-Bonin, Muriel, E-mail: muriel.mercier-bonin@insa-toulouse.fr [Universite de Toulouse, INSA, UPS, INPT, LISBP, 135 Av. de Rangueil, F-31077 Toulouse (France)

2009-11-15

Composite thin films ({approx}170 nm) containing silver nanoclusters embedded in an organosilicon matrix were deposited by PE-CVD onto stainless steel in order to prevent microbial adhesion. The process originality relies on a dual strategy combining silver sputtering and simultaneous plasma polymerization in argon-hexamethyldisiloxane (HMDSO) plasma, using an asymmetrical RF glow discharge. The metal content in the film was controlled by varying the HMDSO flow rate. Investigation of the physico-chemical properties of the obtained films was conducted by X-ray photoelectron spectroscopy and transmission FTIR spectroscopy. Plasma-mediated coatings were composed of C, O, Si and Ag which was predominantly under metallic form, as indicated by XPS analysis. The presence of Si-H, Si-O-Si, Si-(CH){sub n}-Si and C-H groups was established by FTIR. The yeast Saccharomyces cerevisiae was selected as the model for eukaryotic microorganisms. The maximal anti-adhesive efficiency was achieved for the organosilicon matrix alone. When nanosilver was incorporated into the organic matrix, the efficiency was reduced, especially for high metal contents. Silver antimicrobial property was assumed to be related to Ag{sup +} progressive release from the embedded nanoparticles into the surrounding medium. This release was confirmed by ICP-MS measurements. Moreover, silver-containing film antifungal activity was observed towards sessile cells.

Nanotexture Optimization by Oxygen Plasma of Mesoporous Silica Thin Film for Enrichment of Low Molecular Weight Peptides Captured from Human Serum

Science.gov (United States)

Hu, Ye; Peng, Yang; Brousseau, Louis; Bouamrani, Ali; Liu, Xuewu; Ferrari, Mauro

2010-01-01

This study investigated the optimization of mesoporous silica thin films by nanotexturing using oxygen plasma versus thermal oxidation. Calcination in oxygen plasma provides superior control over pore formation with regard to the pore surface and higher fidelity to the structure of the polymer template. The resulting porous film offers an ideal substrate for the selective partitioning of peptides from complex mixtures. The improved chemico-physical characteristics of porous thin films (pore size distribution, nanostructure, surface properties and pore connectivity) were systematically characterized with XRD, Ellipsometry, FTIR, TEM and N2 adsorption/desorption. The enrichment of low molecular weight proteins captured from human serum on mesoporous silica thin films fabricated by both methodologies were investigated by comparison of their MALDI-TOF MS profiles. This novel on-chip fractionation technology offers advantages in recovering the low molecular weight peptides from human serum, which has been recognized as an informative resource for early diagnosis of cancer and other diseases. PMID:21179395

Chemical solution deposition of YBCO thin film by different polymer additives

International Nuclear Information System (INIS)

Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y.; Zhang, H.; Yang, Y.; Cheng, C.H.; Zhao, Y.

2008-01-01

A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T c = 90 K as well as high J c (0 T, 77 K) over 3 MA/cm 2

Chemical solution deposition of YBCO thin film by different polymer additives

Energy Technology Data Exchange (ETDEWEB)

Wang, W.T.; Li, G.; Pu, M.H.; Sun, R.P.; Zhou, H.M.; Zhang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Zhang, H. [Department of Physics, Peking University, Beijing 100871 (China); Yang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia)], E-mail: yzhao@swjtu.edu.cn

2008-09-15

A polymer-assisted chemical solution deposition approach has been proposed for the preparation of YBCO thin film. Different additives like PVB (polyvinyl butyral), PEG (polyethylene glycol) and PVP (polyvinylpyrrolidone) have been used to adjust the final viscosity of the precursor solution and thus the film formation. In this fluorine-free approach, YBCO has been deposited on single crystal substrates with metal acetates being starting materials. Biaxially textured YBCO thin films have been obtained. However, different additives lead to different microstructure. Dense, smooth and crack-free YBCO film prepared with PVB as additive yields sharp superconducting transition around T{sub c} = 90 K as well as high J{sub c} (0 T, 77 K) over 3 MA/cm{sup 2}.

Capillary bending of a thin polymer film floating on a liquid bath

Science.gov (United States)

Twohig, Timothy; Croll, Andrew B.

Thin elastic films and shells are very important in schemes for the encapsulation and protection of fluids from their environment. Capillary origami is a particularly poignant example of how useful fluid/film structures can be formed. The interactions of fluids on thin-films which themselves lie on another surface (fluid or low friction solid) need to be studied if the differences from fluid-fluid and fluid-solid film interfaces are to be fully appreciated. In this experiment, we examine the triple line that occurs when a fluid is resting on a thin polymer film which is itself floating on a second fluid. The top fluid has a high-energy air/fluid interface which can be minimized by deforming the film in a manner that reduces the total air/fluid interface. We create a one-dimensional experiment in order to isolate the basic physics that occurs as the tension of the top fluid pulls on the thin film. Notably, the 1D geometry removes all the complexity incurred by thin films in biaxial stress states (such as wrinkling, folding and crumpling) from the problem. AFOSR under the Young Investigator Program (FA9550-15-1-0168).

Pulsed laser thin film growth of di-octyl substituted polyfluorene and its co-polymers

Energy Technology Data Exchange (ETDEWEB)

Gupta, R.K.; Ghosh, K.; Kahol, P.K. [Department of Physics, Astronomy and Materials Science, Missouri State University, Springfield, MO 65897 (United States); Yoon, J. [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Guha, S. [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States)], E-mail: guhas@missouri.edu

2008-08-30

Matrix-assisted pulsed laser deposition (PLD) allows a controlled layer-by-layer growth of polymer films. Di-octyl substituted polyfluorene (PF8) and its copolymers were deposited as thin films using matrix-assisted PLD by employing a KrF excimer laser with a fluence of 125 mJ/pulses. The optical and structural properties of these films are compared with spincoated films via Raman spectroscopy, absorption and photoluminescence. The Raman spectra of both PLD and spincoated films are similar indicating that the polymer films deposited via PLD maintain their molecular structure. Both the spincoated and the PLD grown PF8 films that were cast from toluene show the presence of the {beta} phase. Benzothiadiazole substituted PF8 (F8BT) and butyl phenyl-substituted PF8 (PFB) PLD grown films show a slightly broader emission compared to the spincoated films, which is attributed to an enhanced intermolecular interaction in the PLD grown thin films.

Pulsed laser thin film growth of di-octyl substituted polyfluorene and its co-polymers

International Nuclear Information System (INIS)

Gupta, R.K.; Ghosh, K.; Kahol, P.K.; Yoon, J.; Guha, S.

2008-01-01

Matrix-assisted pulsed laser deposition (PLD) allows a controlled layer-by-layer growth of polymer films. Di-octyl substituted polyfluorene (PF8) and its copolymers were deposited as thin films using matrix-assisted PLD by employing a KrF excimer laser with a fluence of 125 mJ/pulses. The optical and structural properties of these films are compared with spincoated films via Raman spectroscopy, absorption and photoluminescence. The Raman spectra of both PLD and spincoated films are similar indicating that the polymer films deposited via PLD maintain their molecular structure. Both the spincoated and the PLD grown PF8 films that were cast from toluene show the presence of the β phase. Benzothiadiazole substituted PF8 (F8BT) and butyl phenyl-substituted PF8 (PFB) PLD grown films show a slightly broader emission compared to the spincoated films, which is attributed to an enhanced intermolecular interaction in the PLD grown thin films

Pulsed laser thin film growth of di-octyl substituted polyfluorene and its co-polymers

Science.gov (United States)

Gupta, R. K.; Ghosh, K.; Kahol, P. K.; Yoon, J.; Guha, S.

2008-08-01

Matrix-assisted pulsed laser deposition (PLD) allows a controlled layer-by-layer growth of polymer films. Di-octyl substituted polyfluorene (PF8) and its copolymers were deposited as thin films using matrix-assisted PLD by employing a KrF excimer laser with a fluence of 125 mJ/pulses. The optical and structural properties of these films are compared with spincoated films via Raman spectroscopy, absorption and photoluminescence. The Raman spectra of both PLD and spincoated films are similar indicating that the polymer films deposited via PLD maintain their molecular structure. Both the spincoated and the PLD grown PF8 films that were cast from toluene show the presence of the β phase. Benzothiadiazole substituted PF8 (F8BT) and butyl phenyl-substituted PF8 (PFB) PLD grown films show a slightly broader emission compared to the spincoated films, which is attributed to an enhanced intermolecular interaction in the PLD grown thin films.

Aquatic biofouling prevention by electrically charged nanocomposite polymer thin film membranes.

Science.gov (United States)

de Lannoy, Charles-François; Jassby, David; Gloe, Katie; Gordon, Alexander D; Wiesner, Mark R

2013-03-19

Electrically conductive polymer-nanocomposite (ECPNC) tight nanofiltration (NF) thin film membranes were demonstrated to have biofilm-preventing capabilities under extreme bacteria and organic material loadings. A simple route to the creation and application of these polyamide-carbon nanotube thin films is also reported. These thin films were characterized with SEM and TEM as well as FTIR to demonstrate that the carbon nanotubes are embedded within the polyamide and form ester bonds with trimesoyl chloride, one of the monomers of polyamide. These polymer nanocomposite thin film materials boast high electrical conductivity (∼400 S/m), good NaCl rejection (>95%), and high water permeability. To demonstrate these membranes' biofouling capabilities, we designed a cross-flow water filtration vessel with insulated electrical leads connecting the ECPNC membranes to an arbitrary waveform generator. In all experiments, conducted in highly bacterially contaminated LB media, flux tests were run until fluxes decreased by 45 ± 3% over initial flux. Biofilm-induced, nonreversible flux decline was observed in all control experiments and a cross-flow rinse with the feed solution failed to induce flux recovery. In contrast, flux decrease for the ECPNC membranes with an electric potential applied to their surface was only caused by deposition of bacteria rather than bacterial attachment, and flux was fully recoverable following a short rinse with the feed solution and no added cleaning agents. The prevention of biofilm formation on the ECPNC membranes was a long-term effect, did not decrease with use, and was highly reproducible.

Nanoparticles for dewetting suppression of thin polymer films used in chemical sensors

International Nuclear Information System (INIS)

Holmes, Melissa A.; Mackay, Michael E.; Giunta, Rachel K.

2007-01-01

Addition of fullerenes (C 60 or buckyballs) to a linear polymer has been found to eliminate dewetting when a thin (∼50 nm) film is exposed to solvent vapor. Based on neutron reflectivity measurements, it is found that the fullerenes form a coherent layer approximately 2 nm thick at the substrate - polymer film interface during the spin-coating process. The thickness and relative fullerene concentration (∼29 vol%) is not altered during solvent vapor annealing and it is thought this layer forms a solid-like buffer shielding the adverse van der Waals forces promoted by the underlying substrate. Several polymer films produced by spin- or spray-coating were tested on both silicon wafers and live surface acoustic wave sensors demonstrating fullerenes stabilize many different polymer types, prepared by different procedures and on various surfaces. Further, the fullerenes drastically improve sensor performance since dewetted films produce a sensor that is effectively inoperable

Surface analysis of the selective excimer laser patterning of a thin PEDOT:PSS film on flexible polymer films

Energy Technology Data Exchange (ETDEWEB)

Schaubroeck, David, E-mail: David.Schaubroeck@elis.ugent.be [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 15, B-9052 Ghent (Belgium); De Smet, Jelle; Willems, Wouter [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 15, B-9052 Ghent (Belgium); Cools, Pieter; De Geyter, Nathalie; Morent, Rino [Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering, Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); De Smet, Herbert; Van Steenbeerge, Geert [Center for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 15, B-9052 Ghent (Belgium)

2016-07-15

Highlights: • Laser patterning of thin film PEDOT:PSS on polymer foils is characterized in great detail. • PEDOT:PSS does not need to be fully removed to create electrically insulating patterns. • The underlying polymer foil influences the ablation behavior. - Abstract: Fast patterning of highly conductive polymers like PEDOT:PSS (poly (3,4-ethylene dioxythiophene): polystyrene sulfonate) with lasers can contribute to the development of industrial production of liquid crystal displays on polymer foils. In this article, the selective UV laser patterning of a PEDOT:PSS film on flexible polymer films is investigated. Based on their optical properties, three polymer films are investigated: polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and cellulose triacetate (TAC). Ablation parameters for a 110 nm PEDOT:PSS film on these polymer films are optimized. A detailed study of the crater depth, topography and surface composition are provided using optical profilometry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The electrical insulation of the lines is measured and correlated to the crater analyses for different laser settings. Finally, potential ablation parameters for each of the polymer films are derived.

Deposition of thin films and surface modification by pulsed high energy density plasma

International Nuclear Information System (INIS)

Yan Pengxun; Yang Size

2002-01-01

The use of pulsed high energy density plasma is a new low temperature plasma technology for material surface treatment and thin film deposition. The authors present detailed theoretical and experimental studies of the production mechanism and physical properties of the pulsed plasma. The basic physics of the pulsed plasma-material interaction has been investigated. Diagnostic measurements show that the pulsed plasma has a high electron temperature of 10-100 eV, density of 10 14 -10 16 cm -3 , translation velocity of ∼10 -7 cm/s and power density of ∼10 4 W/cm 2 . Its use in material surface treatment combines the effects of laser surface treatment, electron beam treatment, shock wave bombardment, ion implantation, sputtering deposition and chemical vapor deposition. The metastable phase and other kinds of compounds can be produced on low temperature substrates. For thin film deposition, a high deposition ratio and strong film to substrate adhesion can be achieved. The thin film deposition and material surface modification by the pulsed plasma and related physical mechanism have been investigated. Thin film c-BN, Ti(CN), TiN, DLC and AlN materials have been produced successfully on various substrates at room temperature. A wide interface layer exists between film and substrate, resulting in strong adhesion. Metal surface properties can be improved greatly by using this kind of treatment

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF4/Ar plasma

International Nuclear Information System (INIS)

Joo, Young-Hee; Kim, Chang-Il

2015-01-01

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF 4 /Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF 4 /Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF 4 /Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF 4 /Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar + sputtering and then reacted with the C-F x radicals. • The physical sputtering is dominant in etch control compared with chemical etching

Orienting Block Copolymer Thin Films via Entropy and Surface Plasma Treatment

Science.gov (United States)

Ho, Rong-Ming; Lu, Kai-Yuan; Lo, Ting-Ya; Dehghan, Ashkan; Shi, An-Chang; Prokopios, Georgopanos; Avgeropoulos, Apostolos

Controlling the orientation of nanostructured thin films of block copolymers (BCPs) is essential for next generation lithography. In the thin-film state, how to achieve the perpendicular orientation of the nanostructured microdomains remains challenging due to the interfacial effects from the air and also the substrate, especially for the blocks with silicon containing segments which usually have different surface energies, favoring parallel microdomain orientation. Here, we show that entropic effect can be used to control the orientation of BCP thin films. Specifically, we used the architecture of star-block copolymers consisting of polystyrene (PS) and poly(dimethylsiloxane) (PDMS) blocks to regulate the entropic contribution to the self-assembled nanostructures. Moreover, we aim to achieve the formation of perpendicular orientation from the air surface via surface plasma treatment to neutralize the interfacial energy difference. By combining the architecture effect (entropy effect) on BCP self-assembly and the surface plasma treatment (enthalpy effect), well-defined perpendicular PDMS microdomains in the PS-b-PDMS thin film can be formed from the bottom of non-neutral substrate and the top of the thin film surface, giving great potential for lithographic applications.

Synthesis of electro-active manganese oxide thin films by plasma enhanced chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Merritt, Anna R. [Energetics Research Division, Naval Air Warfare Center Weapons Division, China Lake, CA 93555 (United States); Rajagopalan, Ramakrishnan [Department of Engineering, The Pennsylvania State University, Dubois, PA 15801 (United States); Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Carter, Joshua D. [Energetics Research Division, Naval Air Warfare Center Weapons Division, China Lake, CA 93555 (United States)

2014-04-01

The good stability, cyclability and high specific capacitance of manganese oxide (MnO{sub x}) has recently promoted a growing interest in utilizing MnO{sub x} in asymmetric supercapacitor electrodes. Several literature reports have indicated that thin film geometries of MnO{sub x} provide specific capacitances that are much higher than bulk MnO{sub x} powders. Plasma enhanced chemical vapor deposition (PECVD) is a versatile technique for the production of metal oxide thin films with high purity and controllable thickness. In this work, MnO{sub x} thin films deposited by PECVD from a methylcyclopentadienyl manganese tricarbonyl precursor are presented and the effect of processing conditions on the quality of MnO{sub x} films is described. The film purity and oxidation state of the MnO{sub x} films were studied by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Preliminary electrochemical testing of MnO{sub x} films deposited on carbon fiber electrodes in aqueous electrolytes indicates that the PECVD synthesized films are electrochemically active. - Highlights: • Plasma enhanced chemical vapor deposition of manganese oxide thin films. • Higher plasma power and chamber pressure increase deposition rate. • Manganese oxide thin films are electrochemically active. • Best electrochemical performance observed for pure film with low stress • Lower capacitance observed at higher scan rates despite thin film geometry.

Thin films by metal-organic precursor plasma spray

International Nuclear Information System (INIS)

Schulz, Douglas L.; Sailer, Robert A.; Payne, Scott; Leach, James; Molz, Ronald J.

2009-01-01

While most plasma spray routes to coatings utilize solids as the precursor feedstock, metal-organic precursor plasma spray (MOPPS) is an area that the authors have investigated recently as a novel route to thin film materials. Very thin films are possible via MOPPS and the technology offers the possibility of forming graded structures by metering the liquid feed. The current work employs metal-organic compounds that are liquids at standard temperature-pressure conditions. In addition, these complexes contain chemical functionality that allows straightforward thermolytic transformation to targeted phases of interest. Toward that end, aluminum 3,5-heptanedionate (Al(hd) 3 ), triethylsilane (HSi(C 2 H 5 ) 3 or HSiEt 3 ), and titanium tetrakisdiethylamide (Ti(N(C 2 H 5 ) 2 ) 4 or Ti(NEt 2 ) 4 ) were employed as precursors to aluminum oxide, silicon carbide, and titanium nitride, respectively. In all instances, the liquids contain metal-heteroatom bonds envisioned to provide atomic concentrations of the appropriate reagents at the film growth surface, thus promoting phase formation (e.g., Si-C bond in triethylsilane, Ti-N bond in titanium amide, etc.). Films were deposited using a Sulzer Metco TriplexPro-200 plasma spray system under various experimental conditions using design of experiment principles. Film compositions were analyzed by glazing incidence x-ray diffraction and elemental determination by x-ray spectroscopy. MOPPS films from HSiEt 3 showed the formation of SiC phase but Al(hd) 3 -derived films were amorphous. The Ti(NEt 2 ) 4 precursor gave MOPPS films that appear to consist of nanosized splats of TiOCN with spheres of TiO 2 anatase. While all films in this study suffered from poor adhesion, it is anticipated that the use of heated substrates will aid in the formation of dense, adherent films.

Preparation and characterization of thin organosilicon films deposited on SPR chip

Energy Technology Data Exchange (ETDEWEB)

Szunerits, Sabine [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces (LEPMI), CNRS-INPG-UJF, 1130 rue de la piscine, BP 75, 38402 St. Martin d' Heres Cedex (France)], E-mail: sabine.szunerits@lepmi.inpg.fr; Rich, Sami Abou [Laboratoire de Genie des Procedes d' Interaction de Fluides Reactifs-Materiaux U.S.T.L., Cite Scientifique, 59655 Villeneuve d' Ascq (France); Coffinier, Yannick [Institut de Recherche Interdisciplinaire (IRI), FRE CNRS 2963, Institut d' lectronique, de Microelectronique et de Nanotechnologie (IEMN), UMR CNRS-8520, Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France); Languille, Marie-Angelique [Unite de Catalyse et de Chimie du Solide, UCCS UMR CNRS-8181, Universite des Sciences et Technologies de Lille, Bat. C3, 59655 Villeneuve d' Ascq (France); Supiot, Philippe [Laboratoire de Genie des Procedes d' Interaction de Fluides Reactifs-Materiaux U.S.T.L., Cite Scientifique, 59655 Villeneuve d' Ascq (France); Boukherroub, Rabah [Institut de Recherche Interdisciplinaire (IRI), FRE CNRS 2963, Institut d' lectronique, de Microelectronique et de Nanotechnologie (IEMN), UMR CNRS-8520, Cite Scientifique, Avenue Poincare, BP 60069, 59652 Villeneuve d' Ascq (France)], E-mail: rabah.boukherroub@iemn.univ-lille1.fr

2008-04-20

The paper reports on the preparation and characterization of organosilicon thin polymer films deposited on glass slides coated with 5 nm adhesion layer of titanium and 50 nm of gold. The polymer was obtained by the decomposition of 1,1,3,3-tetramethyldisiloxane precursor (TMDSO) premixed with oxygen induced in a N{sub 2} plasma afterglow using remote plasma-enhanced chemical vapor deposition (PECVD) technique. The film thickness was controlled by laser interferometry and was 9 nm. The chemical stability of the gold substrate coated with the organosilicon polymer film (p-TMDSO) was studied in different acidic and basic solutions (pH 1-14). While the gold/polymer interface showed a high stability in acidic media, the film was almost completely removed in basic solutions. The resulting surfaces were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), water contact angle measurements, cyclic voltammetry, and surface plasmon resonance (SPR)

Preparation and characterization of thin organosilicon films deposited on SPR chip

International Nuclear Information System (INIS)

Szunerits, Sabine; Rich, Sami Abou; Coffinier, Yannick; Languille, Marie-Angelique; Supiot, Philippe; Boukherroub, Rabah

2008-01-01

The paper reports on the preparation and characterization of organosilicon thin polymer films deposited on glass slides coated with 5 nm adhesion layer of titanium and 50 nm of gold. The polymer was obtained by the decomposition of 1,1,3,3-tetramethyldisiloxane precursor (TMDSO) premixed with oxygen induced in a N 2 plasma afterglow using remote plasma-enhanced chemical vapor deposition (PECVD) technique. The film thickness was controlled by laser interferometry and was 9 nm. The chemical stability of the gold substrate coated with the organosilicon polymer film (p-TMDSO) was studied in different acidic and basic solutions (pH 1-14). While the gold/polymer interface showed a high stability in acidic media, the film was almost completely removed in basic solutions. The resulting surfaces were characterized using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), water contact angle measurements, cyclic voltammetry, and surface plasmon resonance (SPR)

In-situ ATR-FTIR for characterization of thin biorelated polymer films

International Nuclear Information System (INIS)

Müller, M.; Torger, B.; Bittrich, E.; Kaul, E.; Ionov, L.; Uhlmann, P.; Stamm, M.

2014-01-01

We present and review in-situ-attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic data from thin biorelated polymer films useful for the modification and functionalization of polymer and inorganic materials and discuss their applications related to life sciences. A special ATR mirror attachment operated by the single-beam-sample-reference (SBSR) concept and housing a homebuilt thermostatable flow cell was used, which allows for appropriate background compensation and signal to noise ratio. ATR-FTIR data on the reactive deposition of dopamine on inorganic model surfaces are shown. Information on the structure and deposition pathway for such bioinspired melanin-like films is provided. ATR-FTIR data on thermosensitive polymer brushes of poly(N-isopropylacrylamide) (PNIPAAM) is then presented. The thermotropic hydration and hydrogen bonding behavior of PNIPAAM brush films is described. Finally, ATR-FTIR data on biorelated polyelectrolyte multilayers (PEM) are given together with details on PEM growth and detection. Applications of these latter films for biopassivation/activation and local drug delivery are addressed

Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

Science.gov (United States)

Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

2017-07-01

In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

Ultrathin Polymer Films, Patterned Arrays, and Microwells

Science.gov (United States)

Yan, Mingdi

2002-05-01

The ability to control and tailor the surface and interface properties of materials is important in microelectronics, cell growth control, and lab-on-a-chip devices. Modification of material surfaces with ultrathin polymer films is attractive due to the availability of a variety of polymers either commercially or by synthesis. We have developed two approaches to the attachment of ultrathin polymer films on solid substrates. In the first method, a silane-functionalized perfluorophenyl azide (PFPA-silane) was synthesized and used to covalently immobilize polymer thin films on silicon wafers. Silanization of the wafer surface with the PFPA-silane introduced a monolayer of azido groups which in turn covalently attached the polymer film by way of photochemically initiated insertion reactions. The thickness of the film could be adjusted by the type and the molecular weight of the polymer. The method is versatile due to the general C-H and/or N-H insertion reactions of crosslinker; and therefore, no specific reactive functional groups on the polymers are required. Using this method, a new type of microwell array was fabricated from covalently immobilized polymer thin films on flat substrates. The arrays were characterized with AFM, XPS, and TOF-SIMS. The second method describes the attachment of polymer thin films on solid substrates via UV irradiation. The procedure consisted of spin-coating a polymer film and irradiating the film with UV light. Following solvent extraction, a thin film remained. The thickness of the film, from a few to over a hundred nanometers, was controlled by varying solution concentration and the molecular weight of the polymer.

Investigation of plasma dynamics during the growth of amorphous titanium dioxide thin films

Science.gov (United States)

Kim, Jin-Soo; Jee, Hyeok; Yu, Young-Hun; Seo, Hye-Won

2018-06-01

We have grown amorphous titanium dioxide thin films by reactive DC sputtering method using a different argon/oxygen partial pressure at a room temperature. The plasma dynamics of the process, reactive and sputtered gas particles was investigated via optical emission spectroscopy. We then studied the correlations between the plasma states and the structural/optical properties of the films. The growth rate and morphology of the titanium dioxide thin films turned out to be contingent with the population and the energy profile of Ar, O, and TiO plasma. In particular, the films grown under energetic TiO plasma have shown a direct band-to-band transition with an optical energy band gap up to ∼4.2 eV.

Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

Science.gov (United States)

Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

2016-01-01

Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties. PMID:27363670

Structural studies of thin films of semiconducting nanoparticles in polymer matrices

International Nuclear Information System (INIS)

Di Luccio, Tiziana; Piscopiello, Emanuela; Laera, Anna Maria; Antisari, Marco Vittori

2007-01-01

Ordered films of nanoscale materials are issue of wide interest for applications in several fields, such as optics, catalysis, and bioelectronics. In particular, semiconducting nanoparticles incorporation in a processable polymer film is an easy way to manipulate such materials for their application. We deposited thin layers of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles embedded in a thermoplastic cyclo-olephin copolymer (COC) with elevated optical transparency and highly bio-compatible. The nanoparticles were obtained by thiolate precursors previously dispersed in the polymer upon thermal treatment at temperatures ranging between 200 and 300 deg. C depending on the desired size. The precursor/polymer solutions were spin-coated in order to get thin films. The spinning conditions were changed in order to optimise the layer thickness and uniformity. The samples were mainly characterised by X-ray reflectivity (XRR) and by high-resolution transmission electron microscopy (HRTEM) analyses. The thinnest layer we have deposited is 8 nm thick, as evaluated by XRR. The HRTEM measurements showed that the nanoparticles have quasi-spherical shape without evident microstructural defects. The size of the nanoparticles depends on the annealing temperature, e.g. at 232 deg. C the size of the CdS nanoparticles is about 4-5 nm

Structural studies of thin films of semiconducting nanoparticles in polymer matrices

Energy Technology Data Exchange (ETDEWEB)

Di Luccio, Tiziana [ENEA, Centro Ricerche Brindisi, SS7 Appia Km 706, I-72100 Brindisi (Italy)], E-mail: tiziana.diluccio@portici.enea.it; Piscopiello, Emanuela; Laera, Anna Maria [ENEA, Centro Ricerche Brindisi, SS7 Appia Km 706, I-72100 Brindisi (Italy); Antisari, Marco Vittori [ENEA, Centro Ricerche Casaccia, Via Anguillarese 301, I-00060 S. Maria di Galeria (Roma) (Italy)

2007-09-15

Ordered films of nanoscale materials are issue of wide interest for applications in several fields, such as optics, catalysis, and bioelectronics. In particular, semiconducting nanoparticles incorporation in a processable polymer film is an easy way to manipulate such materials for their application. We deposited thin layers of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles embedded in a thermoplastic cyclo-olephin copolymer (COC) with elevated optical transparency and highly bio-compatible. The nanoparticles were obtained by thiolate precursors previously dispersed in the polymer upon thermal treatment at temperatures ranging between 200 and 300 deg. C depending on the desired size. The precursor/polymer solutions were spin-coated in order to get thin films. The spinning conditions were changed in order to optimise the layer thickness and uniformity. The samples were mainly characterised by X-ray reflectivity (XRR) and by high-resolution transmission electron microscopy (HRTEM) analyses. The thinnest layer we have deposited is 8 nm thick, as evaluated by XRR. The HRTEM measurements showed that the nanoparticles have quasi-spherical shape without evident microstructural defects. The size of the nanoparticles depends on the annealing temperature, e.g. at 232 deg. C the size of the CdS nanoparticles is about 4-5 nm.

Deposition of polymer films in low pressure reactive plasmas

Energy Technology Data Exchange (ETDEWEB)

Biederman, H.

1981-12-11

Sputtering and plasma polymerization have found wide application as deposition techniques and have been extensively studied. R.f. sputtering of plastics, in particular of polytetrafluoroethylene, are discussed in the first part of this paper. In the second part, the general concept of plasma polymerization is considered and some examples of applications of plasma-polymerized films are presented. Special attention is paid to fluorocarbon and fluorochlorocarbon films. It has been suggested that these films could be used in thin film capacitors or as passivating layers for integrated circuits. In the optical field some of these films have been used as convenient moisture-resistant, protective and antireflecting coatings. Their mechanical properties have also been examined with the intention of using them for reducing surface friction. More recently some metals have been incorporated into fluorocarbon films to obtain layers with novel properties. Experiments in which films were prepared by the plasma polymerization of certain Freons are described. Some electrical and optical properties of these films are presented. High dielectric losses were obtained in a metal/film/metal sandwich configuration and the possible influence of ambient atmospheric effects on these measurements is discussed.

Factors affecting the adhesion of microwave plasma deposited siloxane films on polycarbonate

International Nuclear Information System (INIS)

Muir, B.W.; Thissen, H.; Simon, G.P.; Murphy, P.J.; Griesser, H.J.

2006-01-01

The effects of a radiofrequency oxygen plasma pretreatment and residual water content in the substrate on the adhesion of microwave plasma deposited tetramethyldisiloxane thin films on Bisphenol-A polycarbonate (BPA-PC) were investigated. Samples were characterised using a crosshatch adhesion test, optical and electron microscopy, and X-ray photoelectron spectroscopy. It was found that the use of a low power (5 W) and low treatment time (0.1 s) oxygen plasma can improve adhesion while greater treatment times (1-30 s) and higher oxygen plasma powers (40 W) resulted in a decreased level of adhesion. In addition, it was shown that a BPA-PC water content greater than 90 ppm resulted in rapid adhesion failure of deposited films at the substrate-plasma polymer interface during outdoor weathering. All films degraded substantially when exposed to environmental weathering, indicating ageing reactions within the plasma polymer films themselves, and at the bulk polymer-coating interface

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF{sub 4}/Ar plasma

Energy Technology Data Exchange (ETDEWEB)

Joo, Young-Hee; Kim, Chang-Il

2015-05-29

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF{sub 4}/Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF{sub 4}/Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF{sub 4}/Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF{sub 4}/Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar{sup +} sputtering and then reacted with the C-F{sub x} radicals. • The physical sputtering is dominant in etch control compared with chemical etching.

Plasma-treated Langmuir-Blodgett reduced graphene oxide thin film for applications in biophotovoltaics

Science.gov (United States)

Ibrahim, Siti Aisyah; Jaafar, Muhammad Musoddiq; Ng, Fong-Lee; Phang, Siew-Moi; Kumar, G. Ghana; Majid, Wan Haliza Abd; Periasamy, Vengadesh

2018-01-01

The surface optimization and structural characteristics of Langmuir-Blodgett (LB) reduced graphene oxide thin (rGO) film treated by argon plasma treatment were studied. In this work, six times deposition of rGO was deposited on a clean glass substrate using the LB method. Plasma technique involving a variation of plasma power, i.e., 20, 60, 100 and 140 W was exposed to the LB-rGO thin films under argon ambience. The plasma treatment generally improves the wettability or hydrophilicity of the film surface compared to without treatment. Maximum wettability was observed at a plasma power of 20 W, while also increasing the adhesion of the rGO film with the glass substrate. The multilayer films fabricated were characterized by means of spectroscopic, structural and electrical studies. The treatment of rGO with argon plasma was found to have improved its biocompatibility, and thus its performance as an electrode for biophotovoltaic devices has been shown to be enhanced considerably.

Electric Transport Phenomena of Nanocomposite Organic Polymer Thin Films

Science.gov (United States)

Jira, Nicholas C.; Sabirianov, Ildar; Ilie, Carolina C.

We discuss herein the nanocomposite organic thin film diodes for the use of plasmonic solar cells. This experimental work follows the theoretical calculations done for plasmonic solar cells using the MNPBEM toolbox for MatLab. These calculations include dispersion curves and amount of light scattering cross sections for different metallic nanoparticles. This study gives us clear ideas on what to expect from different metals, allowing us to make the best choice on what to use to obtain the best results. One specific technique for light trapping in thin films solar cells utilizes metal nanoparticles on the surface of the semiconductor. The characteristics of the metal, semiconductor interface allows for light to be guided in between them causing it to be scattered, allowing for more chances of absorption. The samples were fabricated using organic thin films made from polymers and metallic nanoparticles, more specifically Poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate) copolymer and silver or gold nanoparticles. The two fabrication methods applied include spin coating and Langmuir-Blodgett technique. The transport properties are obtained by analyzing the I-V curves. We will also discuss the resistance, resistivity, conductance, density of charge carriers. SUNY Oswego SCAC Grant.

Investigating the crystal growth behavior of biodegradable polymer blend thin films using in situ atomic force microscopy

CSIR Research Space (South Africa)

Malwela, T

2014-01-01

Full Text Available This article reports the crystal growth behavior of biodegradable polylactide (PLA)/poly[(butylene succinate)-co-adipate] (PBSA) blend thin films using atomic force microscopy (AFM). Currently, polymer thin films have received increased research...

Plasma Processing of Metallic and Semiconductor Thin Films in the Fisk Plasma Source

Science.gov (United States)

Lampkin, Gregory; Thomas, Edward, Jr.; Watson, Michael; Wallace, Kent; Chen, Henry; Burger, Arnold

1998-01-01

The use of plasmas to process materials has become widespread throughout the semiconductor industry. Plasmas are used to modify the morphology and chemistry of surfaces. We report on initial plasma processing experiments using the Fisk Plasma Source. Metallic and semiconductor thin films deposited on a silicon substrate have been exposed to argon plasmas. Results of microscopy and chemical analyses of processed materials are presented.

All-organic polymer-dispersed liquid crystal light-valves integrated with electroactive anthraquinone-2-sulfonate-doped polypyrrole thin films as driving electrodes

International Nuclear Information System (INIS)

Wang, Pen-Cheng; Yu, Jing-Yu; Li, Kuan-Hsun

2011-01-01

Highlights: → Fabrication of flexible semi-transparent all-polymer electrodes under ambient conditions without using a CVD system. → Characterization of the above electrodes based on anthraquinone-2-sulfonate-doped polypyrrole thin films. → Demonstration of all-organic liquid crystal light-valves with polypyrrole thin films as the driving electrodes. - Abstract: All-organic PDLC (polymer-dispersed liquid crystal) light-valves using all-polymer conductive substrates containing thin films of polypyrrole doped with anthraquinone-2-sulfonate (AQSA - ) as the driving electrodes were fabricated in this study. The all-polymer conductive substrates were prepared under ambient conditions by in situ depositing polypyrrole thin films on blank flexible poly(ethylene terephthalate), or PET, substrates from aqueous media in which oxidative polymerization of pyrrole was taking place. The obtained flexible all-polymer conductive substrates were semi-transparent with cohesive coatings of AQSA - doped polypyrrole thin films (thickness ∼55 nm). The all-polymer flexible conductive substrates had sheet resistivity ∼40 kΩ □ -1 and T% transparency against air ∼78% at 600 nm. The light-valves fabricated using the above all-polymer conductive substrates showed ∼50% transparency against air at 600 nm when 4 V μm -1 electric field was applied.

Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

International Nuclear Information System (INIS)

Vähä-Nissi, Mika; Pitkänen, Marja; Salo, Erkki; Kenttä, Eija; Tanskanen, Anne; Sajavaara, Timo; Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana; Karppinen, Maarit; Harlin, Ali

2014-01-01

Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al 2 O 3 of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al 2 O 3 thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al 2 O 3 • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli

Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Vähä-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Pitkänen, Marja; Salo, Erkki; Kenttä, Eija [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Tanskanen, Anne, E-mail: Anne.Tanskanen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Sajavaara, Timo, E-mail: timo.sajavaara@jyu.fi [University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 Jyväskylä (Finland); Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Karppinen, Maarit, E-mail: Maarit.Karppinen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Harlin, Ali [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland)

2014-07-01

Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al{sub 2}O{sub 3} of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al{sub 2}O{sub 3} thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al{sub 2}O{sub 3} • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli.

Recent progress in thin film processing by magnetron sputtering with plasma diagnostics

International Nuclear Information System (INIS)

Han, Jeon G

2009-01-01

The precise control of the structure and related properties becomes crucial for sophisticated applications of thin films deposited by magnetron sputtering in emerging industries including the flat panel display, digital electronics and nano- and bio-industries. The film structure is closely related to the total energy delivered to the substrate surface for nucleation and growth during all kinds of thin film processes, including magnetron sputtering. Therefore, the energy delivered to the surface for nucleation and growth during magnetron sputtering should be measured and analysed by integrated diagnostics of the plasma parameters which are closely associated with the process parameters and other external process conditions. This paper reviews the background of thin film nucleation and growth, the status of magnetron sputtering technology and the progress of plasma diagnostics for plasma processing. The evolution of the microstructure during magnetron sputtering is then discussed with respect to the change in the process variables in terms of the plasma parameters along with empirical data of the integrated plasma diagnostics for various magnetron sputtering conditions with conventional dc, pulsed dc and high power pulsed dc sputtering modes. Among the major energy terms to be discussed are the temperature change in the top surface region and the energies of ions and neutral species. (topical review)

Effect of plasma fluorination variables on the deposition and growth of partially fluorinated polymer over PMMA films

Directory of Open Access Journals (Sweden)

Giovana da Silva Padilha

2013-01-01

Full Text Available In this work, an investigation was made of the modification of film surface of Poly(methylmethacrylate (PMMA using the plasma polymerization technique. PMMA films 10 µm thick were obtained by Spin-Coating starting from a chloroform solution (15.36% w/w. The films were exposed to the plasma of CHF3 at different gas pressures and exposure times to increase the thickness of fluorinated polymers onto PMMA films. The plasma fluorinated optical films were characterized by gravimetry, FTIR-ATR, contact angle of wetting, SEM and AFM. The surface fluorination of PMMA films can be inferred by the increase in contact angle under all experimental conditions, and confirmed with FTIR-ATR analysis. Gravimetry showed an increase of the fluorinated polymer layer over PMMA films, being 1.55 µm thick at 0.7 torr and 40 minutes of plasma exposure. The SEM analysis showed a well-defined layer of fluorinated polymer, with fluorine being detected in the EDS analysis. The film roughness for the fluorinated polymers was around of 200 Å, quite satisfactory for a 1.55 µm cladding.

Azaisoindigo conjugated polymers for high performance n-type and ambipolar thin film transistor applications

KAUST Repository

Yue, Wan

2016-09-28

Two new alternating copolymers, PAIIDBT and PAIIDSe have been prepared by incorporating a highly electron deficient azaisoindigo core. The molecular structure and packing of the monomer is determined from the single crystal X-ray diffraction. Both polymers exhibit high EAs and highly planar polymer backbones. When polymers are used as the semiconducting channel for solution-processed thin film transistor application, good properties are observed. A–A type PAIIDBT exhibits unipolar electron mobility as high as 1.0 cm2 V−1 s−1, D–A type PAIIDSe exhibits ambipolar charge transport behavior with predominately electron mobility up to 0.5 cm2 V−1 s−1 and hole mobility to 0.2 cm2 V−1 s−1. The robustness of the extracted mobility values are also commented on in detail. Molecular orientation, thin film morphology and energetic disorder of both polymers are systematically investigated.

Optimized plasma-deposited fluorocarbon coating for dry release and passivation of thin SU-8 cantilevers

DEFF Research Database (Denmark)

Keller, Stephan Urs; Häfliger, Daniel; Boisen, Anja

2008-01-01

during fluorocarbon deposition, the surface free energy of the coating can be tuned to allow for uniform wetting during spin coating of arbitrary thin SU-8 films. Further, they define an optimal pressure regime for the release of thin polymer structures at high yield. They demonstrate the successful......Plasma-deposited fluorocarbon coatings are introduced as a convenient method for the dry release of polymer structures. In this method, the passivation process in a deep reactive ion etch reactor was used to deposit hydrophobic fluorocarbon films. Standard photolithography with the negative epoxy......-based photoresist SU-8 was used to fabricate polymer structures such as cantilevers and membranes on top of the nonadhesive release layer. The authors identify the plasma density as the main parameter determining the surface properties of the deposited fluorocarbon films. They show that by modifying the pressure...

Synthesis and characterization of nanocomposite polymer blend electrolyte thin films by spin-coating method

Energy Technology Data Exchange (ETDEWEB)

Chapi, Sharanappa; Niranjana, M.; Devendrappa, H., E-mail: dehu2010@gmail.com [Department of Physics, Mangalore University, Mangalagangothri - 574 199 (India)

2016-05-23

Solid Polymer blend electrolytes based on Polyethylene oxide (PEO) and poly vinyl pyrrolidone (PVP) complexed with zinc oxide nanoparticles (ZnO NPs; Synthesized by Co-precipitation method) thin films have prepared at a different weight percent using the spin-coating method. The complexation of the NPs with the polymer blend was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR). The variation in film morphology was examined by polarized optical micrographs (POMs). The thermal behavior of blends was investigated under non-isothermal conditions by differential thermal analyses (DTA). A single glass transition temperature for each blend was observed, which supports the existence of compatibility of such system. The obtained results represent that the ternary based thin films are prominent materials for battery and optoelectronic device applications.

Vacuum-integrated electrospray deposition for highly reliable polymer thin film.

Science.gov (United States)

Park, Soohyung; Lee, Younjoo; Yi, Yeonjin

2012-10-01

Vacuum electrospray deposition (ESD) equipment was designed to prepare polymer thin films. The polymer solution can be injected directly into vacuum system through multi-stage pumping line, so that the solvent residues and ambient contaminants are highly reduced. To test the performance of ESD system, we fabricated organic photovoltaic cells (OPVCs) by injecting polymer solution directly onto the substrate inside a high vacuum chamber. The OPVC fabricated has the structure of Al∕P3HT:PCBM∕PEDOT:PSS∕ITO and was optimized by varying the speed of solution injection and concentration of the solution. The power conversion efficiency (PCE) of the optimized OPVC is 3.14% under AM 1.5G irradiation without any buffer layer at the cathode side. To test the advantages of the vacuum ESD, we exposed the device to atmosphere between the deposition steps of the active layer and cathode. This showed that the PCE of the vacuum processed device is 24% higher than that of the air exposed device and confirms the advantages of the vacuum prepared polymer film for high performance devices.

Enhanced magnetoelectric coupling in a composite multiferroic system via interposing a thin film polymer

Science.gov (United States)

Xiao, Zhuyun; Mohanchandra, Kotekar P.; Lo Conte, Roberto; Ty Karaba, C.; Schneider, J. D.; Chavez, Andres; Tiwari, Sidhant; Sohn, Hyunmin; Nowakowski, Mark E.; Scholl, Andreas; Tolbert, Sarah H.; Bokor, Jeffrey; Carman, Gregory P.; Candler, Rob N.

2018-05-01

Enhancing the magnetoelectric coupling in a strain-mediated multiferroic composite structure plays a vital role in controlling magnetism by electric fields. An enhancement of magnetoelastic coupling between ferroelectric single crystal (011)-cut [Pb(Mg1/3Nb2/3)O3](1-x)-[PbTiO3]x (PMN-PT, x≈ 0.30) and ferromagnetic polycrystalline Ni thin film through an interposed benzocyclobutene polymer thin film is reported. A nearly twofold increase in sensitivity of remanent magnetization in the Ni thin film to an applied electric field is observed. This observation suggests a viable method of improving the magnetoelectric response in these composite multiferroic systems.

Controlling hydrophilicity of polymer film by altering gas flow rate in atmospheric-pressure homogeneous plasma

International Nuclear Information System (INIS)

Kang, Woo Seok; Hur, Min; Lee, Jae-Ok; Song, Young-Hoon

2014-01-01

Graphical abstract: - Highlights: • Controlling hydrophilicity of polymer film by varying gas flow rate is proposed in atmospheric-pressure homogeneous plasma treatment. • Without employing additional reactive gas, requiring more plasma power and longer treatment time, hydrophilicity of polyimide films was improved after the low-gas-flow plasma treatment. • The gas flow rate affects the hydrophilic properties of polymer surface by changing the discharge atmosphere in the particular geometry of the reactor developed. • Low-gas-flow induced wettability control suggests effective and economical plasma treatment. - Abstract: This paper reports on controlling the hydrophilicity of polyimide films using atmospheric-pressure homogeneous plasmas by changing only the gas flow rate. The gas flow changed the discharge atmosphere by mixing the feed gas with ambient air because of the particular geometry of the reactor developed for the study, and a low gas flow rate was found to be favorable because it generated abundant nitrogen or oxygen species that served as sources of hydrophilic functional groups over the polymer surface. After low-gas-flow plasma treatment, the polymer surface exhibited hydrophilic characteristics with increased surface roughness and enhanced chemical properties owing to the surface addition of functional groups. Without adding any reactive gases or requiring high plasma power and longer treatment time, the developed reactor with low-gas-flow operation offered effective and economical wettability control of polyimide films

Implantable polymer/metal thin film structures for the localized treatment of cancer by Joule heating

Science.gov (United States)

Kan-Dapaah, Kwabena; Rahbar, Nima; Theriault, Christian; Soboyejo, Wole

2015-04-01

This paper presents an implantable polymer/metal alloy thin film structure for localized post-operative treatment of breast cancer. A combination of experiments and models is used to study the temperature changes due to Joule heating by patterned metallic thin films embedded in poly-dimethylsiloxane. The heat conduction within the device and the surrounding normal/cancerous breast tissue is modeled with three-dimensional finite element method (FEM). The FEM simulations are used to explore the potential effects of device geometry and Joule heating on the temperature distribution and lesion (thermal dose). The FEM model is validated using a gel model that mimics biological media. The predictions are also compared to prior results from in vitro studies and relevant in vivo studies in the literature. The implications of the results are discussed for the potential application of polymer/metal thin film structures in hyperthermic treatment of cancer.

The scanning probe microscopy study of thin polymer films

International Nuclear Information System (INIS)

Harron, H.R.

1995-08-01

Scanning Tunnelling Microscopy and Atomic Force Microscopy were used systematically to investigate the morphology, uniformity, coverage and structure of the thin films of several commercially important insulating polymers. Despite the poorly conducting nature of the polymer sample, detailed and convincing images of this class of materials were achieved by STM without the need to coat the samples with a conductive layer. The polymer regions of the sample were further investigated by the use of surface profiling with 'line scans'. The fluctuations of the amplitude therein enabled important film characteristics to be assessed. An environmental stage was designed for the STM to enable the effect of various vapour-sample interactions to be observed during the imaging process. Using the data from the environmental stage in addition to the surface profiling with line scans, an insight into the conduction mechanism and image interpretation was gained. Results suggest that the water content of the sample and its immediate surroundings is an important factor in achieving reliable STM images in air. The initial study culminated with the observation by STM alone of the plasticizer induced crystallization of uncoated PC thin films. The 'amorphous' PC films were observed before crystallization and small ordered regions in roughly the same proportion as that predicted by diffraction studies [Prietschk, 1959 and Schnell, 1964] were imaged. This has never been observed by a microscopy technique. Furthermore, images of the crystalline film contained elongated units that were attributed to the lamellae formations that form the basic building blocks of polymer spherulites. The study continued with the AFM imaging of the growth of crystalline entities in a PC film, without the need for harsh sample treatment or metal coating. A method of casting and crystallizing the films was developed such that the growth was predominantly in two dimensions and consequently ideal for observation by

Effect of O2 plasma immersion on electrical properties and transistor performance of indium gallium zinc oxide thin films

International Nuclear Information System (INIS)

Liu, P.; Chen, T.P.; Liu, Z.; Tan, C.S.; Leong, K.C.

2013-01-01

Evolution of electrical properties and thin-film transistor characteristics of amorphous indium gallium zinc oxide (IGZO) thin films synthesized by RF sputtering with O 2 plasma immersion has been examined. O 2 plasma immersion results in an enhancement in the Hall mobility and a decrease in the electron concentration; and the transistor performance can be greatly improved by the O 2 plasma immersion. X-ray photoelectron spectroscopy analysis indicates that the effect of O 2 plasma immersion on the electrical properties and the transistor performance can be attributed to the reduction of the oxygen-related defects in the IGZO thin films. - Highlights: • Oxygen plasma immersion effect on indium gallium zinc oxide thin film properties • Oxygen-related defect reduces in the InGaZnO thin film with oxygen plasma immersion. • Increasing oxygen plasma immersion duration on device will decrease the off current. • Oxygen plasma immersion enhances the performance of device

Modified voltammetric, impedimetric and optical behavior of polymer- assisted sol-gel MgFe2O4 nanostructured thin films

International Nuclear Information System (INIS)

Bazhan, Z.; Ghodsi, F.E.; Mazloom, J.

2017-01-01

Highlights: •Electrochemical properties of spinel PEG/PVP MgFe 2 O 4 thin films prepared by spin coating technique have been investigated. •PSD analysis indicated that spectral roughness of films decreased by polymer incorporation. •Optical calculations exhibited a blue shift on optical band gap by polymer addition. •CV curves revealed that ion storage capacitance of PEG/MgFe 2 O 4 is two times higher than MgFe 2 O 4 thin films. •EIS analysis confirmed that incorporation of appropriate amount of PEG reduced the charge transfer resistance. -- Abstract: The effect of polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP) on physical properties of sol-gel prepared magnesium ferrite (MF) thin films was investigated. The X-ray diffraction (XRD) results showed the formation of cubic spinel magnesium ferrite for all samples. The surface morphology of films changed and average surface roughness decreased by polymer addition. The height-height correlation function and fractal dimension were evaluated using cube counting and triangulation methods from atomic force microscopy (AFM) images. The refractive index and extinction coefficient of MF thin films decreased by adding polymer while the band gap value increased from 2.24 to 2.72 eV. The PEG addition enhanced the electrochemical performance while PVP addition didn’t have significant effect on cyclic voltammetry (CV) of magnesium ferrite thin films. The sample with highest value of PEG showed the maximum specific capacitance (68.5 mF cm −2 ) and the smallest charge transfer resistance (565 Ω) among all samples.

Plasma properties during magnetron sputtering of lithium phosphorous oxynitride thin films

DEFF Research Database (Denmark)

Christiansen, Ane Sælland; Stamate, Eugen; Thydén, Karl Tor Sune

2015-01-01

The nitrogen dissociation and plasma parameters during radio frequency sputtering of lithium phosphorus oxynitride thin films in nitrogen gas are investigated by mass appearance spectrometry, electrostatic probes and optical emission spectroscopy, and the results are correlated with electrochemical...... properties and microstructure of the films. Low pressure and moderate power are associated with lower plasma density, higher electron temperature, higher plasma potential and larger diffusion length for sputtered particles. This combination of parameters favors the presence of more atomic nitrogen, a fact...

Control of polymer-packing orientation in thin films through synthetic tailoring of backbone coplanarity

KAUST Repository

Chen, Mark S.

2013-10-22

Controlling solid-state order of π-conjugated polymers through macromolecular design is essential for achieving high electronic device performance; yet, it remains a challenge, especially with respect to polymer-packing orientation. Our work investigates the influence of backbone coplanarity on a polymer\\'s preference to pack face-on or edge-on relative to the substrate. Isoindigo-based polymers were synthesized with increasing planarity by systematically substituting thiophenes for phenyl rings in the acceptor comonomer. This increasing backbone coplanarity, supported by density functional theory (DFT) calculations of representative trimers, leads to the narrowing of polymer band gaps as characterized by ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy and cyclic voltammetry. Among the polymers studied, regiosymmetric II and TII polymers exhibited the highest hole mobilities in organic field-effect transistors (OFETs), while in organic photovoltaics (OPVs), TBII polymers that display intermediate levels of planarity provided the highest power conversion efficiencies. Upon thin-film analysis by atomic force microscropy (AFM) and grazing-incidence X-ray diffraction (GIXD), we discovered that polymer-packing orientation could be controlled by tuning polymer planarity and solubility. Highly soluble, planar polymers favor face-on orientation in thin films while the less soluble, nonplanar polymers favor an edge-on orientation. This study advances our fundamental understanding of how polymer structure influences nanostructural order and reveals a new synthetic strategy for the design of semiconducting materials with rationally engineered solid-state properties. © 2013 American Chemical Society.

Nanometric thin film membranes manufactured on square meter scale: ultra-thin films for CO 2 capture

KAUST Repository

Yave, Wilfredo

2010-09-01

Miniaturization and manipulation of materials at nanometer scale are key challenges in nanoscience and nanotechnology. In membrane science and technology, the fabrication of ultra-thin polymer films (defect-free) on square meter scale with uniform thickness (<100 nm) is crucial. By using a tailor-made polymer and by controlling the nanofabrication conditions, we developed and manufactured defect-free ultra-thin film membranes with unmatched carbon dioxide permeances, i.e. >5 m3 (STP) m-2 h -1 bar-1. The permeances are extremely high, because the membranes are made from a CO2 philic polymer material and they are only a few tens of nanometers thin. Thus, these thin film membranes have potential application in the treatment of large gas streams under low pressure like, e.g., carbon dioxide separation from flue gas. © 2010 IOP Publishing Ltd.

Impact of regioregularity on thin-film transistor and photovoltaic cell performances of pentacene-containing polymers

KAUST Repository

Jiang, Ying

2012-01-01

Regioregular pentacene-containing polymers were synthesized with alkylated bithiophene (BT) and cyclopentadithiophene (CPDT) as comonomers. Among them, 2,9-conjugated polymers PnBT-2,9 and PnCPDT-2,9 achieved the best performance in transistor and photovoltaic devices respectively. The former achieved the most highly ordered structures in thin films, yielding ambipolar transistor behavior with hole and electron mobilities up to 0.03 and 0.02 cm 2 V -1 s -1 on octadecylsilane-treated substrates. The latter achieved photovoltaic power conversion efficiencies up to 0.33%. The impact of regioregularity and direction of conjugation-extension (2,9 vs. 2,10), on thin-film order and device performance has been demonstrated for the pentacene-containing polymers for the first time, providing insight towards future functional material design. © 2012 The Royal Society of Chemistry.

Understanding Interfacial Alignment in Solution Coated Conjugated Polymer Thin Films

International Nuclear Information System (INIS)

Qu, Ge; Zhao, Xikang; Newbloom, Gregory M.; Zhang, Fengjiao; Mohammadi, Erfan

2017-01-01

Domain alignment in conjugated polymer thin films can significantly enhance charge carrier mobility. However, the alignment mechanism during meniscus-guided solution coating remains unclear. Furthermore, interfacial alignment has been rarely studied despite its direct relevance and critical importance to charge transport. In this study, we uncover a significantly higher degree of alignment at the top interface of solution coated thin films, using a donor–acceptor conjugated polymer, poly(diketopyrrolopyrrole-co-thiopheneco- thieno[3,2-b]thiophene-co-thiophene) (DPP2T-TT), as the model system. At the molecular level, we observe in-plane π–π stacking anisotropy of up to 4.8 near the top interface with the polymer backbone aligned parallel to the coating direction. The bulk of the film is only weakly aligned with the backbone oriented transverse to coating. At the mesoscale, we observe a well-defined fibril-like morphology at the top interface with the fibril long axis pointing toward the coating direction. Significantly smaller fibrils with poor orientational order are found on the bottom interface, weakly aligned orthogonal to the fibrils on the top interface. The high degree of alignment at the top interface leads to a charge transport anisotropy of up to 5.4 compared to an anisotropy close to 1 on the bottom interface. We attribute the formation of distinct interfacial morphology to the skin-layer formation associated with high Peclet number, which promotes crystallization on the top interface while suppressing it in the bulk. As a result, we further infer that the interfacial fibril alignment is driven by the extensional flow on the top interface arisen from increasing solvent evaporation rate closer to the meniscus front.

Local variation of fragility and glass transition temperature of ultra-thin supported polymer films.

Science.gov (United States)

Hanakata, Paul Z; Douglas, Jack F; Starr, Francis W

2012-12-28

Despite extensive efforts, a definitive picture of the glass transition of ultra-thin polymer films has yet to emerge. The effect of film thickness h on the glass transition temperature T(g) has been widely examined, but this characterization does not account for the fragility of glass-formation, which quantifies how rapidly relaxation times vary with temperature T. Accordingly, we simulate supported polymer films of a bead-spring model and determine both T(g) and fragility, both as a function of h and film depth. We contrast changes in the relaxation dynamics with density ρ and demonstrate the limitations of the commonly invoked free-volume layer model. As opposed to bulk polymer materials, we find that the fragility and T(g) do not generally vary proportionately. Consequently, the determination of the fragility profile--both locally and for the film as a whole--is essential for the characterization of changes in film dynamics with confinement.

Residual stress in spin-cast polyurethane thin films

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hong; Zhang, Li, E-mail: lizhang@mae.cuhk.edu.hk [Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin N.T., Hong Kong (China); Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin N.T., Hong Kong (China)

2015-01-19

Residual stress is inevitable during spin-casting. Herein, we report a straightforward method to evaluate the residual stress in as-cast polyurethane thin films using area shrinkage measurement of films in floating state, which shows that the residual stress is independent of radial location on the substrate and decreased with decreasing film thickness below a critical value. We demonstrate that the residual stress is developed due to the solvent evaporation after vitrification during spin-casting and the polymer chains in thin films may undergo vitrification at an increased concentration. The buildup of residual stress in spin-cast polymer films provides an insight into the size effects on the nature of polymer thin films.

Effect of sterilization procedures on properties of plasma polymers relevant to biomedical applications

International Nuclear Information System (INIS)

Artemenko, A.; Kylián, O.; Choukourov, A.; Gordeev, I.; Petr, M.; Vandrovcová, M.; Polonskyi, O.; Bačáková, L.; Slavinska, D.; Biederman, H.

2012-01-01

This study is focused on the evaluation of resistance of plasma polymers toward common sterilization techniques, i.e. property important for possible use of such materials in biomedical applications. Three kinds of plasma polymers having different bioadhesive natures were studied: plasma polymerized poly(ethylene oxide), fluorocarbon plasma polymers, and nitrogen-rich plasma polymers. These plasma polymers were subjected to dry heat, autoclave and UV radiation treatment. Their physical, chemical and bioresponsive properties were determined by means of different techniques (ellipsometry, atomic force microscopy, wettability measurements, X-ray photoelectron spectroscopy and biological tests with osteoblast-like cells MG63). The results clearly show that properties of thin films of plasma polymers may be significantly altered by a sterilization process. Moreover, observed changes induced by selected sterilization methods were found to depend strongly on the sterilized plasma polymer. - Highlights: ► Effect of common sterilization methods on three kinds of plasma polymers is studied. ► Physical, chemical and bioresponsive properties of plasma polymers are analyzed. ► Changes induced by sterilization depend strongly on type of the plasma polymer.

Thin aligned organic polymer films for liquid crystal devices

International Nuclear Information System (INIS)

Foster, Kathryn Ellen

1997-01-01

This project was designed to investigate the possibility of producing alignment layers for liquid crystal devices by cross-linking thin films containing anisotropic polymer bound chromophores via irradiation with polarised ultraviolet light. Photocross-linkable polymers find use in microelectronics, liquid crystal displays, printing and UV curable lacquers and inks; so there is an increasing incentive for the development of new varieties of photopolymers in general. The synthesis and characterisation of two new photopolymers that are suitable as potential alignment layers for liquid crystal devices are reported in this thesis. The first polymer contains the anthracene chromophore attached via a spacer unit to a methacrylate backbone and the second used a similarly attached aryl azide group. Copolymers of the new monomers with methyl methacrylate were investigated to establish reactivity ratios in order to understand composition drift during polymerisation. (author)

Crystalline silicon thin film growth by ECR plasma CVD for solar cells

International Nuclear Information System (INIS)

Licai Wang

1999-07-01

This thesis describes the background, motivation and work carried out towards this PhD programme entitled 'Crystalline Silicon Thin Film Growth by ECR Plasma CVD for Solar Cells'. The fundamental principles of silicon solar cells are introduced with a review of silicon thin film and bulk solar cells. The development and prospects for thin film silicon solar cells are described. Some results of a modelling study on thin film single crystalline solar cells are given which has been carried out using a commercially available solar cell simulation package (PC-1D). This is followed by a description of thin film deposition techniques. These include Chemical Vapour Deposition (CVD) and Plasma-Assisted CVD (PACVD). The basic theory and technology of the emerging technique of Electron Cyclotron Resonance (ECR) PACVD, which was used in this research, are introduced and the potential advantages summarised. Some of the basic methods of material and cell characterisation are briefly described, together with the work carried out in this research. The growth by ECR PACVD at temperatures 2 illumination. The best efficiency in the ECR grown structures was 13.76% using an epitaxial emitter. Cell performance was analysed in detail and the factors controlling performance identified by fitting self-consistently the fight and dark current-voltage and spectral response data using PC-1D. Finally, the conclusions for this research and suggestions for further work are outlined. (author)

A comparative study: Effect of plasma on V{sub 2}O{sub 5} nanostructured thin films

Energy Technology Data Exchange (ETDEWEB)

Singh, Megha; Kumar, Prabhat; Sharma, Rabindar K., E-mail: rkrksharma6@gmail.com; Reddy, G. B. [Thin film laboratory, Department of Physics, Indian Institute of Technology Delhi, Delhi (India)

2016-05-06

Vanadium pentoxide nanostructured thin films (NSTs) have been studied to analyze the effect of plasma on nanostructures grown and morphology of films deposited using sublimation process. Nanostructured thin films were deposited on glass substrates, one in presence of oxygen plasma and other in oxygen environment (absence of plasma). Films were characterized using XRD, Raman spectroscopy, SEM and HRTEM. XRD studies revealed α-V{sub 2}O{sub 5} films (orthorhombic phase) with good crystallinity. However, film deposited in presence of plasma have higher peak intensities as compared to those deposited in absence of plasma. Raman studies also support these finding following same trends of considerable increase in intensity in case of film deposited in presence of plasma. SEM micrographs makes the difference more visible, as film deposited in plasma have well defined plate like structures whereas other film have not-clearly-defined petal-like structures. HRTEM results show orthorhombic phase with 0.39 nm interplanar spacing, as reported by XRD. Results are hereby in good agreement with each other.

Self organized striping in ultra thin polymer films near melt: An investigation using Monte Carlo simulation

Science.gov (United States)

Singh, Satya Pal

2018-05-01

This paper work presents the results of Monte Carlo simulation performed for ultra thin short chained polymer films near melt, under strong confinement. Thin polymer films get ruptured when annealed above their glass transition temperatures. The pattern formations are generally explained on the basis of spinodal mechanism, if the thickness of the film is of the order of few tens of nanometers i.e. film seems to tear apart in strips. The free end segments of the chains are more dynamic and coalescence into one another. This process seems to dominate over the spinodal waves resulting into a different type of dynamics. Polymer chains with 30 monomers are taken. 160, 200 and 240 chains are taken for three different cases of the studies. The three cases correspond to three different thickness of the films with 8, 10 and 12 layers of chains along direction perpendicular to the confining substrates. The bottom surface has affinity to monomers, whereas the upper surface has hard wall interaction with the monomers. Different time micrographs of the films are plotted along with density distributions of the monomers to explore the process.

Role of plasma activation in tailoring the nanostructure of multifunctional oxides thin films

Energy Technology Data Exchange (ETDEWEB)

Giangregorio, Maria M.; Losurdo, Maria; Capezzuto, Pio [Institute of Inorganic Methodologies and Plasmas, IMIP-CNR, and Department of Chemistry, University of Bari, via Orabona, 4-70125 Bari (Italy); Bruno, Giovanni [Institute of Inorganic Methodologies and Plasmas, IMIP-CNR, and Department of Chemistry, University of Bari, via Orabona, 4-70125 Bari (Italy)], E-mail: giovanni.bruno@ba.imip.cnr.it

2009-03-01

Potential of O{sub 2} remote plasmas for improving structural, morphological and optical properties of various multifunctional oxides thin films both during plasma assisted growth as well as by post-growth treatments is discussed. In particular, an O{sub 2} remote plasma metalorganic chemical vapor deposition (RP-MOCVD) route is presented for tailoring the structural, morphological and optical properties of Er{sub 2}O{sub 3} and ZnO films. Furthermore, post-growth room-temperature remote O{sub 2} plasma treatments of indium-tin-oxides (ITO) films are demonstrated to be effective in improving morphology of ITO films.

Mixed-Penetrant Sorption in Ultra-Thin Films of Polymer of Intrinsic Microporosity PIM-1

KAUST Repository

Ogieglo, Wojciech; Furchner, Andreas; Ghanem, Bader; Ma, Xiao-Hua; Pinnau, Ingo; Wessling, Matthias

2017-01-01

Mixed penetrant sorption into ultra-thin films of a super-glassy polymer of intrinsic microporosity (PIM-1) was studied for the first time by using interference-enhanced in-situ spectroscopic ellipsometry. PIM-1 swelling and the concurrent changes in its refractive index were determined in ultra-thin (12 - 14 nm) films exposed to pure and mixed penetrants. The penetrants included water, n-hexane and ethanol and were chosen based on their significantly different penetrant-penetrant and penetrant-polymer affinities. This allowed studying microporous polymer responses at diverse ternary compositions and revealed effects such as competition for the sorption sites (for water / n-hexane or ethanol / n-hexane) or enhancement in sorption of typically weakly sorbing water in the presence of more highly sorbing ethanol. The results reveal details of the mutual sorption effects which often complicate comprehension of glassy polymers' behavior in applications such as high-performance membranes, adsorbents or catalysts. Mixed-penetrant effects are typically very challenging to study directly and their understanding is necessary owing to a broadly recognized inadequacy of simple extrapolations from measurements in pure component environment.

Mixed-Penetrant Sorption in Ultra-Thin Films of Polymer of Intrinsic Microporosity PIM-1

KAUST Repository

Ogieglo, Wojciech

2017-10-12

Mixed penetrant sorption into ultra-thin films of a super-glassy polymer of intrinsic microporosity (PIM-1) was studied for the first time by using interference-enhanced in-situ spectroscopic ellipsometry. PIM-1 swelling and the concurrent changes in its refractive index were determined in ultra-thin (12 - 14 nm) films exposed to pure and mixed penetrants. The penetrants included water, n-hexane and ethanol and were chosen based on their significantly different penetrant-penetrant and penetrant-polymer affinities. This allowed studying microporous polymer responses at diverse ternary compositions and revealed effects such as competition for the sorption sites (for water / n-hexane or ethanol / n-hexane) or enhancement in sorption of typically weakly sorbing water in the presence of more highly sorbing ethanol. The results reveal details of the mutual sorption effects which often complicate comprehension of glassy polymers\\' behavior in applications such as high-performance membranes, adsorbents or catalysts. Mixed-penetrant effects are typically very challenging to study directly and their understanding is necessary owing to a broadly recognized inadequacy of simple extrapolations from measurements in pure component environment.

Thickness dependent structural ordering, degradation and metastability in polysilane thin films: A photoluminescence study on representative σ-conjugated polymers

International Nuclear Information System (INIS)

Urbánek, Pavel; Kuřitka, Ivo

2015-01-01

We present a fundamental experimental study based on the fluorescence investigation of thin σ-conjugated polymer films, where the dependence of optoelectrical properties and UV degradation on film thickness ranging from nano- to microscale was studied. Such extensive and detailed study was performed for the first time and observed spectral shifts in emission and excitation spectra and UV degradation retardation point towards the conclusions that there exists a threshold thickness where the material degradation behavior, electron delocalization and structure suddenly change. The development of well aligned polymeric chain structure between the nano- and micrometer thickness (on the mesoscale) was shown responsible for the manifested phenomena. The material thicker than critical 500 nm has extremely small Stokes' shift, maximum extended σ-delocalization along the silicon polymer backbone and exhibits remarkable UV degradation slowdown and self-recovery ability. On the contrary, the electronic properties of thin films below 80 nm resemble those of random coils in solutions. The films of moderate thickness show relatively steep transition between these two modes of structural ordering and resulting properties. Altogether, we consider this complex phenomenon as a consequence of the mesoscale effect, which is an only recently introduced concept in polymer thin films. - Highlights: • Photoluminescence was used as a tool for structural investigation of polysilanes. • Primary study of strong dependence of thin polymer film structure on mesoscale. • A mesoscale effect observed for the first time on sigma conjugated polymers. • Conjugation length is dramatically extended in thicker films than in nanoscale. • Self-recovery effect was shown to be dependent on the mesoscale as well.

Performance of a polymer electrolyte membrane fuel cell with thin film catalyst electrodes

Energy Technology Data Exchange (ETDEWEB)

Chun, Young Gab; Kim, Chang Soo; Peck, Dong Hyun; Shin, Dong Ryul [Korea Institute of Energy Research, Taejon (Korea, Republic of)

1998-03-15

In order to develop a kW-class polymer electrolyte membrane fuel cell (PEMFC), several electrodes have been fabricated by different catalyst layer preparation procedures and evaluated based on the cell performance. Conventional carbon paper and carbon cloth electrodes were fabricated using a ptfe-bonded Pt/C electrol catalyst by coating and rolling methods. Thin-film catalyst/ionomer composite layers were also formed on the membrane by direct coating and transfer printing techniques. The performance evaluation with catalyst layer preparation methods was carried out using a large or small electrode single cell. Conventional and thin film membrane and electrode assemblies (MEAs) with small electrode area showed a performance of 350 and 650 mA/cm{sup 2} at 0.6 V, respectively. The performance of direct coated thin film catalyst layer with 300 cm{sup 2} MEAs was higher than those of the conventional and transfer printing technique MEAs. The influence of some characteristic parameters of the thin film electrode on electrochemical performance was examined. Various other aspects of overall operation of PEMFC stacks were also discussed. (orig.)

Effects of SF6 plasma treatment on the properties of InGaZnO thin films

Science.gov (United States)

Choi, Jinsung; Bae, Byung Seong; Yun, Eui-Jung

2018-03-01

The effects of sulfur hexafluoride (SF6) plasma on the properties of amorphous InGaZnO (a-IGZO) thin films were examined. The properties of the a-IGZO thin films were characterized by Hall effect measurement, dynamic secondary ion mass spectroscopy (SIMS), and X-ray photoelectron spectroscopy (XPS). The IGZO thin films treated with SF6 plasma before annealing had a very high resistance mainly owing to the inclusion of S into the film surface, as evidenced by SIMS profiles. On the other hand, the samples treated with SF6 plasma after annealing showed better electrical properties with a Hall mobility of 10 cm2/(V·s) than the untreated samples or the samples SF6 plasma-treated before annealing. This was attributed to the increase in the number of oxygen vacancy defects in the a-IGZO thin films owing to the enhanced out-diffusion of O to the ambient and the increase in the number of F-related donor defects originating from the incorporation of a much larger amount of F than of S into the film surface, which were confirmed by XPS and SIMS.

The role of Ar plasma treatment in generating oxygen vacancies in indium tin oxide thin films prepared by the sol-gel process

Energy Technology Data Exchange (ETDEWEB)

Hwang, Deuk-Kyu [Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seoul, 03722 (Korea, Republic of); Misra, Mirnmoy; Lee, Ye-Eun [Department of BioNano Technology, Gachon University, 1342 Seong-nam dae-ro, Seong-nam si, Gyeonggi-do, 13120 (Korea, Republic of); Baek, Sung-Doo [Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seoul, 03722 (Korea, Republic of); Myoung, Jae-Min, E-mail: jmmyoung@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seoul, 03722 (Korea, Republic of); Lee, Tae Il, E-mail: t2.lee77@gachon.ac.kr [Department of BioNano Technology, Gachon University, 1342 Seong-nam dae-ro, Seong-nam si, Gyeonggi-do, 13120 (Korea, Republic of)

2017-05-31

Highlights: • Indium tin oxide thin film with about 41 nm thickness was obtained by the sol-gel process. • Thin film exhibited low resistivity. • Sheet resistance of thin film decreases with Ar plasma treatment time. • Ar plasma treatment on thin film does not alter the crystal structure and optical properties of the ITO thin-film. • There is no significant change in oxygen vacancies after 20 min of plasma treatment. - Abstract: Argon (Ar) plasma treatment was carried out to reduce the sheet resistance of indium tin oxide (ITO) thin films. The Ar plasma treatment did not cause any significant changes to the crystal structure, surface morphology, or optical properties of the ITO thin films. However, an X-ray photoelectron spectroscopy study confirmed that the concentration of oxygen vacancies in the film dramatically increased with the plasma treatment time. Thus, we concluded that the decrease in the sheet resistance was caused by the increase in the oxygen vacancy concentration in the film. Furthermore, to verify how the concentration of oxygen vacancies in the film increased with the Ar plasma treatment time, cumulative and continuous plasma treatments were conducted. The oxygen vacancies were found to be created by surface heating via the outward thermal diffusion of oxygen atoms from inside the film.

Plasma polymerized high energy density dielectric films for capacitors

Science.gov (United States)

Yamagishi, F. G.

1983-01-01

High energy density polymeric dielectric films were prepared by plasma polymerization of a variety of gaseous monomers. This technique gives thin, reproducible, pinhole free, conformable, adherent, and insoluble coatings and overcomes the processing problems found in the preparation of thin films with bulk polymers. Thus, devices are prepared completely in a vacuum environment. The plasma polymerized films prepared all showed dielectric strengths of greater than 1000 kV/cm and in some cases values of greater than 4000 kV/cm were observed. The dielectric loss of all films was generally less than 1% at frequencies below 10 kHz, but this value increased at higher frequencies. All films were self healing. The dielectric strength was a function of the polymerization technique, whereas the dielectric constant varied with the structure of the starting material. Because of the thin films used (thickness in the submicron range) surface smoothness of the metal electrodes was found to be critical in obtaining high dielectric strengths. High dielectric strength graft copolymers were also prepared. Plasma polymerized ethane was found to be thermally stable up to 150 C in the presence of air and 250 C in the absence of air. No glass transitions were observed for this material.

Analysis of thin-film polymers using attenuated total internal reflection-Raman microspectroscopy.

Science.gov (United States)

Tran, Willie; Tisinger, Louis G; Lavalle, Luis E; Sommer, André J

2015-01-01

Two methods commonly employed for molecular surface analysis and thin-film analysis of microscopic areas are attenuated total reflection infrared (ATR-IR) microspectroscopy and confocal Raman microspectroscopy. In the former method, the depth of the evanescent probe beam can be controlled by the wavelength of light, the angle of incidence, or the refractive index of the internal reflection element. Because the penetration depth is proportional to the wavelength of light, one could interrogate a smaller film thickness by moving from the mid-infrared region to the visible region employing Raman spectroscopy. The investigation of ATR Raman microspectroscopy, a largely unexplored technique available to Raman microspectroscopy, was carried out. A Renishaw inVia Raman microscope was externally modified and used in conjunction with a solid immersion lens (SIL) to perform ATR Raman experiments. Thin-film polymer samples were analyzed to explore the theoretical sampling depth for experiments conducted without the SIL, with the SIL, and with the SIL using evanescent excitation. The feasibility of micro-ATR Raman was examined by collecting ATR spectra from films whose thickness measured from 200 to 60 nm. Films of these thicknesses were present on a much thicker substrate, and features from the underlying substrate did not become visible until the thin film reached a thickness of 68 nm.

Organic thin film transistors and polymer light-emitting diodes patterned by polymer inking and stamping

International Nuclear Information System (INIS)

Li Dawen; Guo, L Jay

2008-01-01

To fully realize the advantages of organic flexible electronics, patterning is very important. In this paper we show that a purely additive patterning technique, termed polymer inking and stamping, can be used to pattern conductive polymer PEDOT and fabricate sub-micron channel length organic thin film transistors. In addition, we applied the technique to transfer a stack of metal/conjugated polymer in one step and fabricated working polymer light-emitting devices. Based on the polymer inking and stamping technique, a roll-to-roll printing for high throughput fabrication has been demonstrated. We investigated and explained the mechanism of this process based on the interfacial energy consideration and by using the finite element analysis. This technique can be further extended to transfer more complex stacked layer structures, which may benefit the research on patterning on flexible substrates

Flexible thin film magnetoimpedance sensors

International Nuclear Information System (INIS)

Kurlyandskaya, G.V.; Fernández, E.; Svalov, A.; Burgoa Beitia, A.; García-Arribas, A.; Larrañaga, A.

2016-01-01

Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz. - Highlights: • [FeNi/Ti] 3 /Cu/[FeNi/Ti] 3 films were prepared by sputtering at different deposition rates. • Polymer substrates insure sufficiently accurate reproducibility of the film structure. • High deposition rate of 28 nm/min insures the highest values of the magnetoimpedance sensitivity. • Deposition onto polymer results in the satisfactory magnetoimpedance sensitivity of 45%/Oe.

Flexible thin film magnetoimpedance sensors

Energy Technology Data Exchange (ETDEWEB)

Kurlyandskaya, G.V., E-mail: galina@we.lc.ehu.es [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); Ural Federal University, Laboratory of Magnetic sensoric, Lenin Ave. 51, 620083 Ekaterinburg (Russian Federation); Fernández, E. [BCMaterials UPV-EHU, Vizcaya Science and Technology Park, 48160 Derio (Spain); Svalov, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); Ural Federal University, Laboratory of Magnetic sensoric, Lenin Ave. 51, 620083 Ekaterinburg (Russian Federation); Burgoa Beitia, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); García-Arribas, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); BCMaterials UPV-EHU, Vizcaya Science and Technology Park, 48160 Derio (Spain); Larrañaga, A. [SGIker, Servicios Generales de Investigación, Universidad del País Vasco (UPV/EHU), 48080 Bilbao (Spain)

2016-10-01

Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz. - Highlights: • [FeNi/Ti]{sub 3}/Cu/[FeNi/Ti]{sub 3} films were prepared by sputtering at different deposition rates. • Polymer substrates insure sufficiently accurate reproducibility of the film structure. • High deposition rate of 28 nm/min insures the highest values of the magnetoimpedance sensitivity. • Deposition onto polymer results in the satisfactory magnetoimpedance sensitivity of 45%/Oe.

Thin film plasma coatings from dielectric free-flowing materials

International Nuclear Information System (INIS)

Timofeeva, L.A.; Katrich, S.A.; Solntsev, L.A.

1994-01-01

Fabrication of thin film plasma coatings from insulating free-flowing materials is considered. Molybdenum-tart ammonium coating of 3...5 μ thickness deposited on glassy carbon, aluminium, silicon, nickel, cast iron and steel substrates in 'Bulat-ZT' machine using insulating free-flowing materials cathod was found to form due to adsorption, absorption and dissuasion processes. The use of insulating free-flowing materials coatings allow to exclude pure metals cathods in plasma-plating process

Transparent indium zinc oxide thin films used in photovoltaic cells based on polymer blends

International Nuclear Information System (INIS)

Besleaga, Cristina; Ion, L.; Ghenescu, Veta; Socol, G.; Radu, A.; Arghir, Iulia; Florica, Camelia; Antohe, S.

2012-01-01

Indium zinc oxide (IZO) thin films were obtained using pulsed laser deposition. The samples were prepared by ablation of targets with In concentrations, In/(In + Zn), of 80 at.%, at low substrate temperatures under reactive atmosphere. IZO films were used as transparent electrodes in polymer-based – poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 1:1 blend – photovoltaic cells. The action spectra measurements revealed that IZO-based photovoltaic structures have performances comparable with those using indium–tin–oxide as transparent electrode. - Highlights: ► Indium zinc oxide films were grown by pulsed laser deposition at room temperature. ► The films had large free carrier density and reasonably high mobility. ► These films fit for transparent electrodes in polymer-based photovoltaic cells.

Recent Advances in Gas Barrier Thin Films via Layer-by-Layer Assembly of Polymers and Platelets.

Science.gov (United States)

Priolo, Morgan A; Holder, Kevin M; Guin, Tyler; Grunlan, Jaime C

2015-05-01

Layer-by-layer (LbL) assembly has emerged as the leading non-vacuum technology for the fabrication of transparent, super gas barrier films. The super gas barrier performance of LbL deposited films has been demonstrated in numerous studies, with a variety of polyelectrolytes, to rival that of metal and metal oxide-based barrier films. This Feature Article is a mini-review of LbL-based multilayer thin films with a 'nanobrick wall' microstructure comprising polymeric mortar and nano-platelet bricks that impart high gas barrier to otherwise permeable polymer substrates. These transparent, water-based thin films exhibit oxygen transmission rates below 5 × 10(-3) cm(3) m(-2) day(-1) atm(-1) and lower permeability than any other barrier material reported. In an effort to put this technology in the proper context, incumbent technologies such as metallized plastics, metal oxides, and flake-filled polymers are briefly reviewed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heparin molecularly imprinted polymer thin flm on gold electrode by plasma-induced graft polymerization for label-free biosensor.

Science.gov (United States)

Orihara, Kouhei; Hikichi, Atsushi; Arita, Tomohiko; Muguruma, Hitoshi; Yoshimi, Yasuo

2018-03-20

Heparin, a highly sulfated glycosaminoglycan, is an important biomaterial having biological and therapeutic functionalities such as anticoagulation, regeneration, and protein stabilization. This study addresses a label-free quartz crystal microbalance (QCM) biosensor for heparin detection based on a macromolecularly imprinted polymer (MIP) as an artificial recognition element. We demonstrate the novel strategy for MIP in the form of thin film on a gold (Au) electrode with the plasma-induced graft polymerization (PIP) technique. The procedure of PIP is as follows: (i) Hexamethyldisiloxane plasma-polymerized thin film (PPF) as a pre-coating scaffold of active species for PIP (post-polymerization) is deposited on an Au electrode. (ii) The PPF/Au electrode is soaked in an water solution containing heparin (template), (2-(methacryloxy)-ethyl)trimethylammonium chloride acrylamide (functional monomer), acrylamide, and N,N-methylenebisacrylamide (crosslinker). Double bonds of monomer and crosslinker attacked by residually active species in pre-coating PPF cause radical chain reaction. Consequently, a growing polymer network of 20 nm thickness of PIP-MIP thin film is formed and grafted on the PPF/Au surface. (iii) The PIP-MIP/PPF/Au is washed by sodium chloride solution so as to remove the template. Non-imprinted polymer (NIP) is carried out like the same procedure without a template. The AFM, XPS, and QCM measurements show that the PIP process facilitates macromolecularly surface imprinting of template heparin where the template is easily removed and is rapidly rebound to PIP-MIP without a diffusional barrier. The heparin-PIP-MIP specifically binds to heparin compared with heparin analog chondroitin sulfate C (selective factor: 4.0) and a detectable range of heparin in the presence of CS (0.1 wt%) was 0.001-0.1 wt%. The PIP-NIP does not show selectivity between them. The evaluated binding kinetics are association (k a  = 350 ± 100 M -1  s -1

Plasma-polymerized perfluoro(methylcyclohexane) coating on ethylene propylene diene elastomer surface: Effect of plasma processing condition on the deposition kinetics, morphology and surface energy of the film

International Nuclear Information System (INIS)

Tran, N.D.; Dutta, N.K.; Choudhury, N. Roy

2005-01-01

Plasma polymerization of perfluoro (methylcyclohexane) was carried out under cold plasma process operated at 13.56 MHz to deposit pore-free, uniform, ultra-thin film on an ethylene propylene diene terpolymer (EPDM) substrate in a view to modify the surface characteristics. The plasma fluoropolymeric films were formed at different plasma treatment times (from 20 s to 16 min), applied powers (20 to 100 W) and precursor flow rates to produce high quality films in a controllable yet tunable fashion. Scanning electron microscopy was employed successfully to characterize the evolution of the morphological feature in the film and also to determine the thickness of the coating. The surface energy of the film was determined by sessile drop method using different solvents as probe liquids. It is observed that a pore-free homogeneous plasma polymer thin film is formed within 20 s of treatment time, however, the morphology of the film depends on the plasma processing conditions, such as plasma power, precursor flow rate and deposition time. With increased time and power at a constant flow rate, the morphology of the film progressively changes from flat smooth to globular and rough. The kinetics and activation energy of the plasma polymer film deposition process were also estimated. The surface energy of the EPDM substrate decreased dramatically with plasma coating, however, it appears to be independent of the treatment time

Effect of sterilization procedures on properties of plasma polymers relevant to biomedical applications

Energy Technology Data Exchange (ETDEWEB)

Artemenko, A. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Kylian, O., E-mail: ondrej.kylian@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Choukourov, A.; Gordeev, I.; Petr, M. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Vandrovcova, M. [Institute of Physiology, Academy of Sciences of the Czech Republic, Department of Growth and Differentiation of Cell Populations, Videnska 1083, 142 20, Prague 4 (Czech Republic); Polonskyi, O. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic); Bacakova, L. [Institute of Physiology, Academy of Sciences of the Czech Republic, Department of Growth and Differentiation of Cell Populations, Videnska 1083, 142 20, Prague 4 (Czech Republic); Slavinska, D.; Biederman, H. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holesovickach 2, 180 00 Prague (Czech Republic)

2012-10-01

This study is focused on the evaluation of resistance of plasma polymers toward common sterilization techniques, i.e. property important for possible use of such materials in biomedical applications. Three kinds of plasma polymers having different bioadhesive natures were studied: plasma polymerized poly(ethylene oxide), fluorocarbon plasma polymers, and nitrogen-rich plasma polymers. These plasma polymers were subjected to dry heat, autoclave and UV radiation treatment. Their physical, chemical and bioresponsive properties were determined by means of different techniques (ellipsometry, atomic force microscopy, wettability measurements, X-ray photoelectron spectroscopy and biological tests with osteoblast-like cells MG63). The results clearly show that properties of thin films of plasma polymers may be significantly altered by a sterilization process. Moreover, observed changes induced by selected sterilization methods were found to depend strongly on the sterilized plasma polymer. - Highlights: Black-Right-Pointing-Pointer Effect of common sterilization methods on three kinds of plasma polymers is studied. Black-Right-Pointing-Pointer Physical, chemical and bioresponsive properties of plasma polymers are analyzed. Black-Right-Pointing-Pointer Changes induced by sterilization depend strongly on type of the plasma polymer.

Superhydrophobic Thin Films Fabricated by Reactive Layer-by-Layer Assembly of Azlactone-Functionalized Polymers.

Science.gov (United States)

Buck, Maren E; Schwartz, Sarina C; Lynn, David M

2010-09-11

We report an approach to the fabrication of superhydrophobic thin films that is based on the 'reactive' layer-by-layer assembly of azlactone-containing polymer multilayers. We demonstrate that films fabricated from alternating layers of the azlactone functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) and poly(ethyleneimine) (PEI) exhibit micro- and nanoscale surface features that result in water contact angles in excess of 150º. Our results reveal that the formation of these surface features is (i) dependent upon film thickness (i.e., the number of layers of PEI and PVDMA deposited) and (ii) that it is influenced strongly by the presence (or absence) of cyclic azlactone-functionalized oligomers that can form upon storage of the 2-vinyl-4,4-dimethylazlactone (VDMA) used to synthesize PVDMA. For example, films fabricated using polymers synthesized in the presence of these oligomers exhibited rough, textured surfaces and superhydrophobic behavior (i.e., advancing contact angles in excess of 150º). In contrast, films fabricated from PVDMA polymerized in the absence of this oligomer (e.g., using freshly distilled monomer) were smooth and only moderately hydrophobic (i.e., advancing contact angles of ~75º). The addition of authentic, independently synthesized oligomer to samples of distilled VDMA at specified and controlled concentrations permitted reproducible fabrication of superhydrophobic thin films on the surfaces of a variety of different substrates. The surfaces of these films were demonstrated to be superhydrophobic immediately after fabrication, but they became hydrophilic after exposure to water for six days. Additional experiments demonstrated that it was possible to stabilize and prolong the superhydrophobic properties of these films (e.g., advancing contact angles in excess of 150° even after complete submersion in water for at least six weeks) by exploiting the reactivity of residual azlactones to functionalize the surfaces of the films

Improved polymer thin-film wetting behavior through nanoparticle segregation to interfaces

International Nuclear Information System (INIS)

Krishnan, R S; Mackay, M E; Duxbury, P M; Hawker, C J; Asokan, Suba; Wong, Michael S; Goyette, Rick; Thiyagarajan, P

2007-01-01

We report a systematic study of improved wetting behavior for thin polymer films containing nanoparticles, as a function of nanoparticle size and concentration, the energy of the substrate and the dielectric properties of the nanoparticles. An enthalpy matched system consisting of polystyrene nanoparticles in linear polystyrene is used to show that nanoparticles are uniformly distributed in the film after spin coating and drying. However, on annealing the film above its bulk glass transition temperature these nanoparticles segregate strongly to the solid substrate. We find that for a wide range of film thicknesses and nanoparticle sizes, a substrate coverage of nanoparticles of approximately a monolayer is required for dewetting inhibition. Cadmium selenide quantum dots also inhibit dewetting of polystyrene thin films, again when a monolayer is present. Moreover, TEM microscopy images indicate that CdSe quantum dots segregate primarily to the air interface. Theoretical interpretation of these phenomena suggests that gain of linear chain configurational entropy promotes segregation of nanoparticles to the solid substrate, as occurs for polystyrene nanoparticles; however, for CdSe nanoparticles this is offset by surface energy or enthalpic terms which promote segregation of the nanoparticles to the air interface

Tunable Gas Permeability of Polymer-Clay Nano Brick Wall Thin Film Assemblies

Science.gov (United States)

Gamboa, Daniel; Priolo, Morgan; Grunlan, Jaime

2010-03-01

Thin films of anionic natural montmorrilonite (MMT) clay and cationic polyethylenimine (PEI) have been produced by alternately dipping a plastic substrate into dilute aqueous mixtures containing each ingredient. After 40 polymer-clay layers have been deposited, the resulting transparent film exhibits an oxygen transmission rate (OTR) below 0.35 cm^3/m^2 . day when the pH of PEI solution is 10. This low permeability is due to a brick wall nanostructure comprised of completely exfoliated clay bricks in polymeric mortar. This brick wall creates an extremely tortuous path at thicknesses below 250 nm and clay concentration above 80 wt%. A 70-bilayer PEI-MMT assembly has an undetectable OTR (< 0.005 cm^3/m^2 . day), which equates to a permeability below SiOx when multiplied by its film thickness of 231 nm. With optical transparency greater than 86% and the ability to be microwaved, these thin film composites are good candidates for flexible electronics packaging and foil replacement for food.

Characterization of Thin Film Polymers Through Dynamic Mechanical Analysis and Permeation

Science.gov (United States)

Herring, Helen

2003-01-01

Thin polymer films are being considered, as candidate materials to augment the permeation resistance of cryogenic hydrogen fuel tanks such as would be required for future reusable launch vehicles. To evaluate performance of candidate films after environmental exposure, an experimental study was performed to measure the thermal/mechanical and permeation performance of six, commercial-grade materials. Dynamic storage modulus, as measured by Dynamic Mechanical Analysis, was found over a range of temperatures. Permeability, as measured by helium gas diffusion, was found at room temperature. Test data was correlated with respect to film type and pre-test exposure to moisture, elevated temperature, and cryogenic temperature. Results indicated that the six films were comparable in performance and their resistance to environmental degradation.

Improved electrochemical performances of oxygen plasma treated LiMn2O4 thin films

International Nuclear Information System (INIS)

Chen, C C; Chiu, K-F; Lin, K M; Lin, H C; Yang, C-R; Wang, F M

2007-01-01

LiMn 2 O 4 spinel thin films were deposited by radio frequency (rf) magnetron sputtering followed by annealing at 600 0 C in air.The films were then post-treated with an rf driven oxygen plasma. The crystallization and surface morphology of LiMn 2 O 4 thin films were seen to change with rf power. The treated samples were tested under harsh conditions such as deep discharge to 1.5 V and cycling at elevated temperature of 60 0 C to verify the electrochemical performances of LiMn 2 O 4 cathodes. The oxygen plasma treatments improved the electrochemical properties of LiMn 2 O 4 thin films significantly. As the cells were cycled in the range of 4.5-2.0 V at 60 0 C, the samples treated at a proper rf power of 50 W exhibited an initial capacity greater than ∼400 mAh g -1 with reasonable cycling stability. The results were attributed to the change of morphology and the formation of a surface layer induced by the oxygen plasma irradiation

Surface characterization of hydrophobic thin films deposited by inductively coupled and pulsed plasmas

International Nuclear Information System (INIS)

Kim, Youngsoo; Lee, Ji-Hye; Kim, Kang-Jin; Lee, Yeonhee

2009-01-01

Different fluorocarbon thin films were deposited on Si substrates using a plasma-polymerization method. Fluorine-containing hydrophobic thin films were obtained by inductively coupled plasma (ICP) and pulsed plasma (PP) with a mixture of fluorocarbon precursors C 2 F 6 , C 3 F 8 , and c-C 4 F 8 and the unsaturated hydrocarbons of C 2 H 2 . The influence on the fluorocarbon surfaces of the process parameters for plasma polymerization, including the gas ratio and the plasma power, were investigated under two plasma-polymerized techniques with different fluorocarbon gas precursors. The hydrophobic properties, surface morphologies, and chemical compositions were elucidated using water contact angle measurements, field emission-scanning electron microscope, x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). In this study, the ICP technique provides coarser grained films and more hydrophobic surfaces as well as a higher deposition rate compared to the PP technique. XPS, FT-IR, and TOF-SIMS analyses indicated that the ICP technique produced more fluorine-related functional groups, including CF 2 and CF 3 , on the surface. From the curve-fitted XPS results, fluorocarbon films grown under ICP technique exhibited less degree of cross-linking and higher CF 2 concentrations than those grown under PP technique.

Thin Film & Deposition Systems (Windows)

Data.gov (United States)

Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

Biomimetic thin film synthesis

Energy Technology Data Exchange (ETDEWEB)

Graff, G.L.; Campbell, A.A.; Gordon, N.R.

1995-05-01

The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

Silicon nanowires in polymer nanocomposites for photovoltaic hybrid thin films

International Nuclear Information System (INIS)

Ben Dkhil, S.; Bourguiga, R.; Davenas, J.; Cornu, D.

2012-01-01

Highlights: ► Hybrid solar cells based on blends of poly(N-vinylcarbazole) and silicon nanowires have been fabricated. ► We have investigated the charge transfer between PVK and SiNWs by the way of the quenching of the PVK photoluminescence. ► The relation between the morphology of the composite thin films and the charge transfer between SiNWs and PVK has been examined. ► We have investigated the effects of SiNWs concentration on the photovoltaic characteristics leading to the optimization of a critical SiNWs concentration. - Abstract: Hybrid thin films combining the high optical absorption of a semiconducting polymer film and the electronic properties of silicon fillers have been investigated in the perspective of the development of low cost solar cells. Bulk heterojunction photovoltaic materials based on blends of a semiconductor polymer poly(N-vinylcarbazole) (PVK) as electron donor and silicon nanowires (SiNWs) as electron acceptor have been studied. Composite PVK/SiNWs films were cast from a common solvent mixture. UV–visible spectrometry and photoluminescence of the composites have been studied as a function of the SiNWs concentration. Photoluminescence spectroscopy (PL) shows the existence of a critical SiNWs concentration of about 10 wt % for PL quenching corresponding to the most efficient charge pair separation. The photovoltaic (PV) effect has been studied under illumination. The optimum open-circuit voltage V oc and short-circuit current density J sc are obtained for 10 wt % SiNWs whereas a degradation of these parameters is observed at higher SiNWs concentrations. These results are correlated to the formation of aggregates in the composite leading to recombination of the photogenerated charge pairs competing with the dissociation mechanism.

Surface characterization of selected polymer thin films by total-reflection x-ray fluorescence spectroscopy and x-ray reflectivity

International Nuclear Information System (INIS)

Innis, Vallerie Ann A.

2006-01-01

Development of available x-ray characterizations tools for grazing incidence techniques was done to be able to probe nano-size thin films. Alignment of a Philips x-ray powder diffractometer was improved to let it perform as an x-ray reflectometer. X-ray reflectometry was coupled with total-reflection x-ray fluorescence spectroscopy. Evaluation of the performance of this grazing incidence techniques was done by preparing polymer thin films of carboxymethylcellulose, carrageenan and polyvinylpyrrolidone (PVP). The thickness of the films were varied by varying the process parameters such as concentration, spin speed and spin time. Angle-dispersive total-reflection x-ray fluorescence spectroscopy profiles of three films showed film formation only in carrageenan and PVP. For both carrageenan and PVP, an increase in concentration yielded a corresponding increase in intensity of the fluorescent or scattered peaks. XRR profiles of carrageenan thin films yielded a mean value for the critical angle close to quartz substrate. Thickness measurements of the prepared carrageenan thin films showed that concentration was the main determinant for final film thickness over the other process parameters. Sulfur fluorescent intensity derived from the TXRF measurement showed a linear relationship with the measured thickness by XRR. For PVP, measured critical angle is lower than quartz. Poor adhesion of the polymer onto the substrate yielded a limited number of thickness measurements made from the XRR profiles. (Author)

Analysis of polymer surfaces and thin-film coatings with Raman and surface enhanced Raman scattering

International Nuclear Information System (INIS)

McAnally, Gerard David

2001-01-01

This thesis investigates the potential of surface-enhanced Raman scattering (SERS) for the analysis and characterisation of polymer surfaces. The Raman and SERS spectra from a PET film are presented. The SERS spectra from the related polyester PBT and from the monomer DMT are identical to PET, showing that only the aromatic signals are enhanced. Evidence from other compounds is presented to show that loss of the carbonyl stretch (1725 cm -1 ) from the spectra is due to a chemical interaction between the silver and surface carbonyl groups. The interaction of other polymer functional groups with silver is discussed. A comparison of Raman and SERS spectra collected from three faces of a single crystal shows the SERS spectra are depolarised. AFM images of the silver films used to obtain SERS are presented. They consist of regular islands of silver, fused together to form a complete film. The stability and reproducibility and of these surfaces is assessed. Band assignments for the SERS spectrum of PET are presented. A new band in the spectrum (1131 cm -1 ) is assigned to a complex vibration using a density functional calculation. Depth profiling through a polymer film on to the silver layer showed the SERS signals arise from the silver surface only. The profiles show the effects of refraction on the beam, and the adverse affect on the depth resolution. Silver films were used to obtain SERS spectra from a 40 nm thin-film coating on PET, without interference from the PET layer. The use of an azo dye probe as a marker to detect the coating is described. Finally, a novel method for the synthesis of a SERS-active vinyl-benzotriazole monomer is reported. The monomer was incorporated into a thin-film coating and the SERS spectrum obtained from the polymer. (author)

Polymorphous silicon thin films produced in dusty plasmas: application to solar cells

International Nuclear Information System (INIS)

Roca i Cabarrocas, Pere; Chaabane, N; Kharchenko, A V; Tchakarov, S

2004-01-01

We summarize our current understanding of the optimization of PIN solar cells produced by plasma enhanced chemical vapour deposition from silane-hydrogen mixtures. To increase the deposition rate, the discharge is operated under plasma conditions close to powder formation, where silicon nanocrystals contribute to the deposition of so-called polymorphous silicon thin films. We show that the increase in deposition rate can be achieved via an accurate control of the plasma parameters. However, this also results in a highly defective interface in the solar cells due to the bombardment of the P-layer by positively charged nanocrystals during the deposition of the I-layer. We show that decreasing the ion energy by increasing the total pressure or by using silane-helium mixtures allows us to increase both the deposition rate and the solar cells efficiency, as required for cost effective thin film photovoltaics

Confinement Effects on Host Chain Dynamics in Polymer Nanocomposite Thin Films

Energy Technology Data Exchange (ETDEWEB)

Johnson, Kyle J. [Department; Glynos, Emmanouil [Department; Maroulas, Serafeim-Dionysios [Department; Narayanan, Suresh [Advanced; Sakellariou, Georgios [Department; Green, Peter F. [Department; National

2017-09-06

Incorporating nanoparticles (NPs) within a polymer host to create polymer nanocomposites (PNCs) while having the effect of increasing the functionality (e.g.: sensing, energy conversion) of these materials, introduces additional complications with regard to the processing-morphology-function behavior. A primary challenge is to understand and control the viscosity of a PNC with decreasing film thickness confinement for nanoscale applications. Using a combination of X-ray photon correlation spectroscopy (XPCS) and X-ray standing wave based resonance enhanced XPCS to study the dynamics of neat poly-2-vinyl pyridine (P2VP) chains and the nanoparticle dynamics, respectively, we identified a new mechanism that dictates the viscosity of PNC films in the nanoscale regime. We show that while the viscosities of neat P2VP films as thin as 50 nm remained the same as the bulk, PNC films containing P2VP brush-coated gold NPs, spaced 50 nm apart, exhibited unprecedented increases in viscosities of over an order of magnitude. For thicker films or more widely separated NPs, the chain dynamics and viscosities were equal to the bulk values. These results -NP proximities and suppression of their dynamics -suggest a new mechanism by which the viscosities of polymeric liquids could be controlled for 2D and 3D nanoscale applications.

Handbook of thin film technology

CERN Document Server

Frey, Hartmut

2015-01-01

“Handbook of Thin Film Technology” covers all aspects of coatings preparation, characterization and applications. Different deposition techniques based on vacuum and plasma processes are presented. Methods of surface and thin film analysis including coating thickness, structural, optical, electrical, mechanical and magnetic properties of films are detailed described. The several applications of thin coatings and a special chapter focusing on nanoparticle-based films can be found in this handbook. A complete reference for students and professionals interested in the science and technology of thin films.

Surface Passivation of Silicon Using HfO2 Thin Films Deposited by Remote Plasma Atomic Layer Deposition System.

Science.gov (United States)

Zhang, Xiao-Ying; Hsu, Chia-Hsun; Lien, Shui-Yang; Chen, Song-Yan; Huang, Wei; Yang, Chih-Hsiang; Kung, Chung-Yuan; Zhu, Wen-Zhang; Xiong, Fei-Bing; Meng, Xian-Guo

2017-12-01

Hafnium oxide (HfO 2 ) thin films have attracted much attention owing to their usefulness in equivalent oxide thickness scaling in microelectronics, which arises from their high dielectric constant and thermodynamic stability with silicon. However, the surface passivation properties of such films, particularly on crystalline silicon (c-Si), have rarely been reported upon. In this study, the HfO 2 thin films were deposited on c-Si substrates with and without oxygen plasma pretreatments, using a remote plasma atomic layer deposition system. Post-annealing was performed using a rapid thermal processing system at different temperatures in N 2 ambient for 10 min. The effects of oxygen plasma pretreatment and post-annealing on the properties of the HfO 2 thin films were investigated. They indicate that the in situ remote plasma pretreatment of Si substrate can result in the formation of better SiO 2 , resulting in a better chemical passivation. The deposited HfO 2 thin films with oxygen plasma pretreatment and post-annealing at 500 °C for 10 min were effective in improving the lifetime of c-Si (original lifetime of 1 μs) to up to 67 μs.

Modification of low temperature deposited LiMn2O4 thin film cathodes by oxygen plasma irradiation

International Nuclear Information System (INIS)

Chen, Chen Chung; Chiu, Kuo-Feng; Lin, Kun Ming; Lin, Hsin Chih

2009-01-01

Lithium manganese oxides have been deposited by radio frequency magnetron sputter deposition with relatively lower annealing temperatures and then post-treated with a radio frequency (rf) driven oxygen plasma. Following oxygen plasma irradiation, the film properties were modified, and the performance of the thin film cathode has been enhanced. The electrochemical properties of the treated thin-film cathodes were characterized and compared. The results showed that the samples with moderate plasma treatment also maintained good cyclic properties as cycled at a wide range potential window of 2.0 V-4.5 V. Its electrochemical properties were significantly improved by this process, even though the films were prepared under low annealing temperature.

Nanocomposite metal/plasma polymer films prepared by means of gas aggregation cluster source

Energy Technology Data Exchange (ETDEWEB)

Polonskyi, O.; Solar, P.; Kylian, O.; Drabik, M.; Artemenko, A.; Kousal, J.; Hanus, J.; Pesicka, J.; Matolinova, I. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Kolibalova, E. [Tescan, Libusina trida 21, 632 00 Brno (Czech Republic); Slavinska, D. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Biederman, H., E-mail: bieder@kmf.troja.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic)

2012-04-02

Nanocomposite metal/plasma polymer films have been prepared by simultaneous plasma polymerization using a mixture of Ar/n-hexane and metal cluster beams. A simple compact cluster gas aggregation source is described and characterized with emphasis on the determination of the amount of charged clusters and their size distribution. It is shown that the fraction of neutral, positively and negatively charged nanoclusters leaving the gas aggregation source is largely influenced by used operational conditions. In addition, it is demonstrated that a large portion of Ag clusters is positively charged, especially when higher currents are used for their production. Deposition of nanocomposite Ag/C:H plasma polymer films is described in detail by means of cluster gas aggregation source. Basic characterization of the films is performed using transmission electron microscopy, ultraviolet-visible and Fourier-transform infrared spectroscopies. It is shown that the morphology, structure and optical properties of such prepared nanocomposites differ significantly from the ones fabricated by means of magnetron sputtering of Ag target in Ar/n-hexane mixture.

Preparation of anatase TiO2 thin films by vacuum arc plasma evaporation

International Nuclear Information System (INIS)

Miyata, Toshihiro; Tsukada, Satoshi; Minami, Tadatsugu

2006-01-01

Anatase titanium dioxide (TiO 2 ) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO 2 pellets as the source material. Highly transparent TiO 2 thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O 2 ) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO 2 thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO 2 thin film with a resistivity of 2.6 x 10 -1 Ω cm was prepared at a substrate temperature of 400 deg. C without the introduction of O 2 gas

Polymer-coated compliant receivers for intact laser-induced forward transfer of thin films: experimental results and modelling

Science.gov (United States)

Feinaeugle, Matthias; Horak, Peter; Sones, Collin L.; Lippert, Thomas; Eason, Rob W.

2014-09-01

In this study, we investigate both experimentally and numerically laser-induced forward transfer (LIFT) of thin films to determine the role of a thin polymer layer coating the receiver with the aim of modifying the rate of deceleration and reduction of material stress preventing intact material transfer. A numerical model of the impact phase during LIFT shows that such a layer reduces the modelled stress. The evolution of stress within the transferred deposit and the substrate as a function of the thickness of the polymer layer, the transfer velocity and the elastic properties of the polymer are evaluated. The functionality of the polymer layer is verified experimentally by LIFT printing intact 1- m-thick bismuth telluride films and polymeric light-emitting diode pads onto a layer of 12-m-thick polydimethylsiloxane and 50-nm-thick poly(3,4-ethylenedioxythiophene) blended with poly(styrenesulfonate) (PEDOT:PSS), respectively. Furthermore, it is demonstrated experimentally that the introduction of such a compliant layer improves adhesion between the deposit and its substrate.

Electrochemical Synthesis of a Microporous Conductive Polymer Based on a Metal-Organic Framework Thin Film

KAUST Repository

Lu, Chunjing; Ben, Teng; Xu, Shixian; Qiu, Shilun

2014-01-01

A new approach to preparing 3D microporous conductive polymer has been demonstrated in the electrochemical synthesis of a porous polyaniline network with the utilization of a MOF thin film supported on a conducting substrate. The prepared porous

Production of selective membranes using plasma deposited nanochanneled thin films

Directory of Open Access Journals (Sweden)

Rodrigo Amorim Motta Carvalho

2006-12-01

Full Text Available The hydrolization of thin films obtained by tetraethoxysilane plasma polymerization results in the formation of a nanochanneled silicone like structure that could be useful for the production of selective membranes. Therefore, the aim of this work is to test the permeation properties of hydrolyzed thin films. The films were tested for: 1 permeation of polar organic compounds and/or water in gaseous phase and 2 permeation of salt in liquid phase. The efficiency of permeation was tested using a quartz crystal microbalance (QCM technique in gas phase and conductimetric analysis (CA in liquid phase. The substrates used were: silicon for characterization of the deposited films, piezoelectric quartz crystals for tests of selective membranes and cellophane paper for tests of permeation. QCM analysis showed that the nanochannels allow the adsorption and/or permeation of polar organic compounds, such as acetone and 2-propanol, and water. CA showed that the films allow salt permeation after an inhibition time needed for hydrolysis of the organic radicals within the film. Due to their characteristics, the films can be used for grains protection against microorganism proliferation during storage without preventing germination.

Structure-processing-property correlations in thin films of conjugated polymer nanocomposites and blends

Science.gov (United States)

Sreeram, Arvind

Conjugated polymers have found several applications in recent years, in energy conversion and storage devices such as organic light emitting diodes, solar cells, batteries, and super capacitors. Thin films of polymers used for these applications need to be mechanically and thermally stable to withstand the harsh operating conditions. Although there is significant information on the optoelectronic properties of many of these polymers, there are only few studies on their mechanical properties. There is little information in the literature on how processing of these films influence mechanical properties. In the first part of this study, poly(p-phenylene vinylene) (PPV) films were prepared by thermolytic conversion of poly[p -phenylene (tetrahydrothiophenium)ethylene chloride] precursor films, at different temperatures and the kinetics of reaction was investigated using thermogravimetry and Fourier transform infrared (FTIR) spectroscopy. The mechanical properties of the films, studied using nanoindentation, showed a dependence on the extent of conversion and chemical composition of the films. The presence of chemical defects (e.g., carbonyl groups, detected using FTIR spectroscopy), was also found to have a noticeable effect on the modulus and hardness of the films. The storage modulus, E', and plasticity decreased with an increase in conversion, whereas the loss modulus, E", showed the opposite trend. Both the precursor and the fully-converted PPV films were found to have significantly lower E" than E', consistent with the glassy nature of the polymers at room temperature. In the second part of the study, polyacetylene films were synthesized by acid-catalyzed dehydration reaction of poly(vinyl alcohol) (PVA) precursor films. The kinetics of this reaction was monitored by thermogravimetry. The chemical structure of the conjugated polymer films was characterized by Raman and IR spectroscopy. Polyacetylene films incorporated with 1-propyl-3-methylimidazolium ionic liquid

Plasma interactions determine the composition in pulsed laser deposited thin films

Science.gov (United States)

Chen, Jikun; Döbeli, Max; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas

2014-09-01

Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La0.6Sr0.4MnO3, we demonstrate for as grown La0.6Sr0.4MnO3-δ films that a congruent transfer of metallic species is achieved in two pressure windows: ˜10-3 mbar and ˜2 × 10-1 mbar. In the intermediate pressure range, La0.6Sr0.4MnO3-δ becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

Diketopyrrolopyrrole-Based Conjugated Polymer Entailing Triethylene Glycols as Side Chains with High Thin-Film Charge Mobility without Post-Treatments

Energy Technology Data Exchange (ETDEWEB)

Yang, Si-Fen [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; University of Chinese Academy of Sciences, Beijing 100049 P. R. China; Liu, Zi-Tong [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; Cai, Zheng-Xu [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; Dyson, Matthew J. [Department of Materials and Centre for Plastic Electronics, Imperial College London, London SW72AZ UK; Stingelin, Natalie [Department of Materials and Centre for Plastic Electronics, Imperial College London, London SW72AZ UK; Chen, Wei [Materials Science Division, Argonne National Laboratory, 9700 Cass Avenue Lemont IL 60439 USA; Institute for Molecular Engineering, The University of Chicago, 5640 South Ellis Avenue Chicago IL 60637 USA; Ju, Hua-Jun [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; Zhang, Guan-Xin [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; Zhang, De-Qing [Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 P. R. China; University of Chinese Academy of Sciences, Beijing 100049 P. R. China

2017-04-18

Side chain engineering of conjugated donor-acceptor polymers is a new way to manipulate their optoelectronic properties. Two new diketopyrrolopyrrole (DPP)-terthiophene-based conjugated polymers PDPP3T-1 and PDPP3T-2, with both hydrophilic triethylene glycol (TEG) and hydrophobic alkyl chains, are reported. It is demonstrated that the incorporation of TEG chains has a significant effect on the interchain packing and thin-film morphology with noticeable effect on charge transport. Polymer chains of PDPP3T-1 in which TEG chains are uniformly distributed can self-assemble spontaneously into a more ordered thin film. As a result, the thin film of PDPP3T-1 exhibits high saturated hole mobility up to 2.6 cm(2) V-1 s(-1) without any post-treatment. This is superior to those of PDPP3T with just alkyl chains and PDPP3T-2. Moreover, the respective field effect transistors made of PDPP3T-1 can be utilized for sensing ethanol vapor with high sensitivity (down to 100 ppb) and good selectivity.

Crack density and electrical resistance in indium-tin-oxide/polymer thin films under cyclic loading

KAUST Repository

Mora Cordova, Angel; Khan, Kamran; El Sayed, Tamer

2014-01-01

Here, we propose a damage model that describes the degradation of the material properties of indium-tin-oxide (ITO) thin films deposited on polymer substrates under cyclic loading. We base this model on our earlier tensile test model and show

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

Energy Technology Data Exchange (ETDEWEB)

Manaa, C., E-mail: chadlia.el.manaa@gmail.com [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Lejeune, M. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Kouki, F. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Durand-Drouhin, O. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Bouchriha, H. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); and others

2014-06-02

We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method.

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

International Nuclear Information System (INIS)

Manaa, C.; Lejeune, M.; Kouki, F.; Durand-Drouhin, O.; Bouchriha, H.

2014-01-01

We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method

Laser Deposition of Polymer Nanocomposite Thin Films and Hard Materials and Their Optical Characterization

Science.gov (United States)

2013-12-05

visible light on instruments such as microscope tips and micro- surgical tools. Hard carbon known as diamond-like carbon films produced by pulsed laser ...visible (610 nm) LED source and a supplemental infra-red 980-nm laser diode (for the studies of the upconversion fluorescence). The basic package...5/2013 Final Performance Report 15 Sep 2012- 14 Sep 2013 LASER DEPOSITION OF POLYMER NANOCOMPOSITE THIN FILMS AND HARD MATERIALS AND THEIR OPTICAL

Effect of Polymer Binders on UV-Responsive Organic Thin-Film Phototransistors with Benzothienobenzothiophene Semiconductor.

Science.gov (United States)

Ljubic, Darko; Smithson, Chad S; Wu, Yiliang; Zhu, Shiping

2016-02-17

The influence of polymer binders on the UV response of organic thin-film phototransistors (OTF-PTs) is reported. The active channel of the OTF-PTs was fabricated by blending a UV responsive 2,7-dipenty-[1]benzothieno[2,3-b][1]benzothiophene (C5-BTBT) as small molecule semiconductor and a branched unsaturated polyester (B-upe) as dielectric binder (ratio 1:1). To understand the influence of the polymer composition on the photoelectrical properties and UV response of C5-BTBT, control blends were prepared using common dielectric polymers, namely, poly(vinyl acetate) (PVAc), polycarbonate (PC), and polystyrene (PS), for comparison. Thin-film morphology and nanostructure of the C5-BTBT/polymer blends were investigated by means of optical and atomic force microscopy, and powder X-ray diffraction, respectively. Electrical and photoelectrical characteristics of the studied OTF-PTs were evaluated in the dark and under UV illumination with a constant light intensity (P = 3 mW cm(-2), λ = 365 nm), respectively, using two- and three-terminal I-V measurements. Results revealed that the purposely chosen B-upe polymer binder strongly affected the UV response of OTF-PTs. A photocurrent increase of more than 5 orders of magnitude in the subthreshold region was observed with a responsivity as high as 9.7 AW(-1), at VG = 0 V. The photocurrent increase and dramatic shift of VTh,average (∼86 V) were justified by the high number of photogenerated charge carriers upon the high trap density in bulk 8.0 × 10(12) cm(-2) eV(-1) generated by highly dispersed C5-BTBT in B-upe binder. Compared with other devices, the B-upe OTF-PTs had the fastest UV response times (τr1/τr2 = 0.5/6.0) reaching the highest saturated photocurrent (>10(6)), at VG = -5 V and VSD = -60 V. The enhanced UV sensing properties of B-upe based OTF-PTs were attributed to a self-induced thin-film morphology. The enlarged interface facilitated the electron withdrawing/donating functional groups in the polymer chains in

Efficient protein-repelling thin films regulated by chain mobility of low-Tg polymers with increased stability via crosslinking

Science.gov (United States)

Zhang, Jinghui; Huang, Zhiwei; Liu, Dan

2017-12-01

Polymer thin films are generally employed as coatings on implants to prevent protein adsorption. Polymer chain mobility and surface softness have been found to contribute to the protein resistance, but also bring film instability in a liquid protein medium. We investigated the protein resistance ability of three low-Tg polymers, including hydrophobic polymers polyisoprene (PI), poly(n-butyl methacrylate) (PnBMA) and hydrophilic polyethylene oxide (PEO), by overcoming the instability issue with crosslinking. We found that the Tgs of PI and PEO can be increased to around 0 °C after crosslinking. The remained strong chain mobility of both films can still resist protein adsorption regardless the hydrophobicity, yet greatly increases the film stability under an aqueous circumstance. The PnBMA film increased its Tg to around room temperature after crosslinking, which deteriorated the protein-resistance ability having the surface covered by BSA molecules. Our results support that the chain mobility of a polymer film plays an important role in resisting protein adsorption due to the increased entropy associated with more mobile polymer chains. By tune the degree of crosslinking, the stability of polymer in aqueous environment can be increased while the protein resistant ability can be remained. Our results provide a new strategy to design polymer materials for effective antifouling.

Room temperature synthesis of porous SiO2 thin films by plasma enhanced chemical vapor deposition

OpenAIRE

Barranco Quero, Ángel; Cotrino Bautista, José; Yubero Valencia, Francisco; Espinós, J. P.; Rodríguez González-Elipe, Agustín

2004-01-01

Synthesis of porous SiO2 thin films in room temperature was carried out using plasma enhanced chemical vapor deposition (CVD) in an electron cyclotron resonance microwave reactor with a downstream configuration.The gas adsorption properties and the type of porosity of the SiO2 thin films were assessed by adsorption isotherms of toluene at room temperature.The method could also permit the tailoring synthesis of thin films when both composition and porosity can be simultaneously and independent...

Mesoscopic layered structure in conducting polymer thin film fabricated by potential-programmed electropolymerization

Energy Technology Data Exchange (ETDEWEB)

Fujitsuka, Mamoru (Div. of Molecular Engineering, Kyoto Univ. (Japan)); Nakahara, Reiko (Div. of Molecular Engineering, Kyoto Univ. (Japan)); Iyoda, Tomokazu (Div. of Molecular Engineering, Kyoto Univ. (Japan)); Shimidzu, Takeo (Div. of Molecular Engineering, Kyoto Univ. (Japan)); Tomita, Shigehisa (Toray Research Center Co., Ltd., Shiga (Japan)); Hatano, Yayoi (Toray Research Center Co., Ltd., Shiga (Japan)); Soeda, Fusami (Toray Research Center Co., Ltd., Shiga (Japan)); Ishitani, Akira (Toray Research Center Co., Ltd., Shiga (Japan)); Tsuchiya, Hajime (Nitto Technical Information Center Co., Ltd., Shimohozumi Ibaraki, Osaka (Japan)); Ohtani, Akira (Central Research Lab., Nitto Denko Co., Ltd., Shimohozumi Ibaraki, Osaka (Japan))

1992-11-01

Mesoscopic layered structures in conducting polymer thin films are fabricated by the potential-programmed electropolymerization method. High lateral quality in the layered structure is realized by the improvement of polymerization conditions, i.e., a mixture of pyrrole and bithiophene as monomers, a silicon single-crystal wafer as a working electrode and propylene carbonate as a solvent. SIMS depth profiling of the resulting layered films indicates a significant linear correlation between the electric charge passed and the thickness of the individual layers on a 100 A scale. (orig.)

Nanocrystalline LiMn2O4 thin film cathode material prepared by polymer spray pyrolysis method for Li-ion battery

International Nuclear Information System (INIS)

Karthick, S.N.; Richard Prabhu Gnanakan, S.; Subramania, A.; Kim, Hee-Je

2010-01-01

Nanocrystalline cubic spinel lithium manganese oxide thin film was prepared by a polymer spray pyrolysis method using lithium acetate and manganese acetate precursor solution and polyethylene glycol-4000 as a polymeric binder. The substrate temperature was selected from the thermogravimetric analysis by finding the complete crystallization temperature of LiMn 2 O 4 precursor sample. The deposited LiMn 2 O 4 thin films were annealed at 450, 500 and 600 o C for 30 min. The thin film annealed at 600 o C was found to be the sufficient temperature to form high phase pure nanocrystalline LiMn 2 O 4 thin film. The formation of cubic spinel thin film was confirmed by X-ray diffraction study. Scanning electron microscopy and atomic force microscopy analysis revealed that the thin film annealed at 600 o C was found to be nanocrystalline in nature and the surface of the films were uniform without any crack. The electrochemical charge/discharge studies of the prepared LiMn 2 O 4 film was found to be better compared to the conventional spray pyrolysed thin film material.

Thin films of polymer blends deposited by matrix-assisted pulsed laser evaporation: Effects of blending ratios

International Nuclear Information System (INIS)

Paun, Irina Alexandra; Ion, Valentin; Moldovan, Antoniu; Dinescu, Maria

2011-01-01

In this work, we show successful use of matrix-assisted pulsed laser evaporation (MAPLE) for obtaining thin films of PEG:PLGA blends, in the view of their use for controlled drug delivery. In particular, we investigate the influence of the blending ratios on the characteristics of the films. We show that the roughness of the polymeric films is affected by the ratio of each polymer within the blend. In addition, we perform Fourier transformed infrared spectroscopy (FTIR) measurements and we find that the intensities ratios of the infrared absorption bands of the two polymers are consistent with the blending ratios. Finally, we assess the optical constants of the polymeric films by spectroscopic ellipsometry (SE). We point out that the blending ratios exert an influence on the optical characteristics of the films and we validate the SE results by atomic force microscopy and UV-vis spectrophotometry. In all, we stress that the ratios in which the two polymers are blended have significant impact on the morphology, chemical structure and optical characteristics of the polymeric films deposited by MAPLE.

Nanoscale thermal-mechanical probe determination of 'softening transitions' in thin polymer films

International Nuclear Information System (INIS)

Zhou Jing; Berry, Brian; Douglas, Jack F; Karim, Alamgir; Snyder, Chad R; Soles, Christopher

2008-01-01

We report a quantitative study of the softening behavior of glassy polystyrene (PS) films at length scales on the order of 100 nm using nano-thermomechanometry (nano-TM), an emerging scanning probe technique in which a highly doped silicon atomic force microscopy (AFM) tip is resistively heated on the surface of a polymer film. The apparent 'softening temperature' T s of the film is found to depend on the logarithm of the square root of the thermal ramping rate R. This relation allows us to estimate a quasi-equilibrium (or zero rate) softening transition temperature T s0 by extrapolation. We observe marked shifts of T s0 with decreasing film thickness, but the nature of these shifts, and even their sign, depend strongly on both the thermal and mechanical properties of the supporting substrate. Finite element simulations suggest that thin PS films on rigid substrates with large thermal conductivities lead to increasing T s0 with decreasing film thickness, whereas softer, less thermally conductive substrates promote reductions in T s0 . Experimental observations on a range of substrates confirm this behavior and indicate a complicated interplay between the thermal and mechanical properties of the thin PS film and the substrate. This study directly points to relevant factors for quantitative measurements of thermophysical properties of materials at the nanoscale using this nano-TM based method.

Tuning Bandgap of p-Type Cu2Zn(Sn, Ge)(S, Se)4 Semiconductor Thin Films via Aqueous Polymer-Assisted Deposition.

Science.gov (United States)

Yi, Qinghua; Wu, Jiang; Zhao, Jie; Wang, Hao; Hu, Jiapeng; Dai, Xiao; Zou, Guifu

2017-01-18

Bandgap engineering of kesterite Cu 2 Zn(Sn, Ge)(S, Se) 4 with well-controlled stoichiometric composition plays a critical role in sustainable inorganic photovoltaics. Herein, a cost-effective and reproducible aqueous solution-based polymer-assisted deposition approach is developed to grow p-type Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films with tunable bandgap. The bandgap of Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films can be tuned within the range 1.05-1.95 eV using the aqueous polymer-assisted deposition by accurately controlling the elemental compositions. One of the as-grown Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films exhibits a hall coefficient of +137 cm 3 /C. The resistivity, concentration and carrier mobility of the Cu 2 ZnSn(S, Se) 4 thin film are 3.17 ohm·cm, 4.5 × 10 16 cm -3 , and 43 cm 2 /(V·S) at room temperature, respectively. Moreover, the Cu 2 ZnSn(S, Se) 4 thin film when used as an active layer in a solar cell leads to a power conversion efficiency of 3.55%. The facile growth of Cu 2 Zn(Sn, Ge)(S, Se) 4 thin films in an aqueous system, instead of organic solvents, provides great promise as an environmental-friendly platform to fabricate a variety of single/multi metal chalcogenides for the thin film industry and solution-processed photovoltaic devices.

Plasma-deposited fluorocarbon polymer films on titanium for preventing cell adhesion: a surface finishing for temporarily used orthopaedic implants

Science.gov (United States)

Finke, B.; Testrich, H.; Rebl, H.; Walschus, U.; Schlosser, M.; Zietz, C.; Staehlke, S.; Nebe, J. B.; Weltmann, K. D.; Meichsner, J.; Polak, M.

2016-06-01

The design of a titanium implant surface should ideally support its later application in clinical use. Temporarily used implants have to fulfil requirements different from permanent implants: they should ensure the mechanical stabilization of the bone stock but in trauma surgery they should not be integrated into the bone because they will be removed after fracture healing. Finishing of the implant surface by a plasma-fluorocarbon-polymer (PFP) coating is a possible approach for preventing cell adhesion of osteoblasts. Two different low pressure gas-discharge plasma processes, microwave (MW 2.45 GHz) and capacitively coupled radio frequency (RF 13.56 MHz) plasma, were applied for the deposition of the PFP film using a mixture of the precursor octafluoropropane (C3F8) and hydrogen (H2). The thin films were characterized by x-ray photoelectron spectroscopy, Fourier transform infrared reflection absorption spectroscopy, and water contact angle measurements. Cell culture experiments show that cell adhesion and spreading of MG-63 osteoblasts were clearly reduced or nonexistent on these surfaces, also after 24 h of storage in the cell culture medium. In vivo data demonstrated that the local inflammatory tissue response for the PFP films deposited in MW and RF plasma were comparable to uncoated controls.

Thermal Vapor Deposition and Characterization of Polymer-Ceramic Nanoparticle Thin Films and Capacitors

Science.gov (United States)

Iwagoshi, Joel A.

Research on alternative energies has become an area of increased interest due to economic and environmental concerns. Green energy sources, such as ocean, wind, and solar power, are subject to predictable and unpredictable generation intermittencies which cause instability in the electrical grid. This problem could be solved through the use of short term energy storage devices. Capacitors made from composite polymer:nanoparticle thin films have been shown to be an economically viable option. Through thermal vapor deposition, we fabricated dielectric thin films composed of the polymer polyvinylidine fluoride (PVDF) and the ceramic nanoparticle titanium dioxide (TiO2). Fully understanding the deposition process required an investigation of electrode and dielectric film deposition. Film composition can be controlled by the mass ratio of PVDF:TiO2 prior to deposition. An analysis of the relationship between the ratio of PVDF:TiO2 before and after deposition will improve our understanding of this novel deposition method. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy were used to analyze film atomic concentrations. The results indicate a broad distribution of deposited TiO2 concentrations with the highest deposited amount at an initial mass concentration of 17% TiO2. The nanoparticle dispersion throughout the film is analyzed through atomic force microscopy and energy dispersive x-ray spectroscopy. Images from these two techniques confirm uniform TiO2 dispersion with cluster size less than 300 nm. These results, combined with spectroscopic analysis, verify control over the deposition process. Capacitors were fabricated using gold parallel plates with PVDF:TiO 2 dielectrics. These capacitors were analyzed using the atomic force microscope and a capacohmeter. Atomic force microscope images confirm that our gold films are acceptably smooth. Preliminary capacohmeter measurements indicate capacitance values of 6 nF and break down voltages of 2.4 V

Transparent conductive ZnO layers on polymer substrates: Thin film deposition and application in organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Dosmailov, M. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Leonat, L.N. [Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical Chemistry, Johannes Kepler University Linz, A-4040 Linz (Austria); Patek, J. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Roth, D.; Bauer, P. [Institute of Experimental Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Scharber, M.C.; Sariciftci, N.S. [Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical Chemistry, Johannes Kepler University Linz, A-4040 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

2015-09-30

Aluminum doped ZnO (AZO) and pure ZnO thin films are grown on polymer substrates by pulsed-laser deposition and the optical, electrical, and structural film properties are investigated. Laser fluence, substrate temperature, and oxygen pressure are varied to obtain transparent, conductive, and stoichiometric AZO layers on polyethylene terephthalate (PET) that are free of cracks. At low fluence (1 J/cm{sup 2}) and low pressure (10{sup −3} mbar), AZO/PET samples of high optical transmission in the visible range, low electrical sheet resistance, and high figure of merit (FOM) are produced. AZO films on fluorinated ethylene propylene have low FOM. The AZO films on PET substrates are used as electron transport layer in inverted organic solar cell devices employing P3HT:PCBM as photovoltaic polymer-fullerene bulk heterojunction. - Highlights: • Aluminum doped and pure ZnO thin films are grown on polyethylene terephthalate. • Growth parameters laser fluence, temperature, and gas pressure are optimized. • AZO films on PET have high optical transmission and electrical conductance (FOM). • Organic solar cells on PET using AZO as electron transport layer are made. • Power conversion efficiency of these OSC devices is measured.

Preparation of anatase TiO{sub 2} thin films by vacuum arc plasma evaporation

Energy Technology Data Exchange (ETDEWEB)

Miyata, Toshihiro [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)]. E-mail: tmiyata@neptune.kanazawa-it.ac.jp; Tsukada, Satoshi [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan); Minami, Tadatsugu [Optoelectronic Device System R and D Center, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501 (Japan)

2006-02-01

Anatase titanium dioxide (TiO{sub 2}) thin films with high photocatalytic activity have been prepared with deposition rates as high as 16 nm/min by a newly developed vacuum arc plasma evaporation (VAPE) method using sintered TiO{sub 2} pellets as the source material. Highly transparent TiO{sub 2} thin films prepared at substrate temperatures from room temperature to 400 deg. C exhibited photocatalytic activity, regardless whether oxygen (O{sub 2}) gas was introduced during the VAPE deposition. The highest photocatalytic activity and photo-induced hydrophilicity were obtained in anatase TiO{sub 2} thin films prepared at 300 deg. C, which correlated to the best crystallinity of the films, as evidenced from X-ray diffraction. In addition, a transparent and conductive anatase TiO{sub 2} thin film with a resistivity of 2.6 x 10{sup -1} {omega} cm was prepared at a substrate temperature of 400 deg. C without the introduction of O{sub 2} gas.

Mass Transfer in Amperometric Biosensors Based on Nanocomposite Thin Films of Redox Polymers and Oxidoreductases

Directory of Open Access Journals (Sweden)

Aleksandr L. Simonian

2002-03-01

Full Text Available Mass transfer in nanocomposite hydrogel thin films consisting of alternating layers of an organometallic redox polymer (RP and oxidoreductase enzymes was investigated. Multilayer nanostructures were fabricated on gold surfaces by the deposition of an anionic self-assembled monolayer of 11-mercaptoundecanoic acid, followed by the electrostatic binding of a cationic redox polymer, poly[vinylpyridine Os(bis-bipyridine2Clco-allylamine], and an anionic oxidoreductase. Surface plasmon resonance spectroscopy, Fourier transform infrared external reflection spectroscopy (FTIR-ERS, ellipsometry and electrochemistry were employed to characterize the assembly of these nanocomposite films. Simultaneous SPR/electrochemistry enabled real time observation of the assembly of sensing components, changes in film structure with electrode potential, and the immediate, in situ electrochemical verification of substrate-dependent current upon the addition of enzyme to the multilayer structure. SPR and FTIR-ERS studies also showed no desorption of polymer or enzyme from the nanocomposite structure when stored in aqueous environment occurred over the period of three weeks, suggesting that decreasing in substrate sensitivity were due to loss of enzymatic activity rather than loss of film compounds from the nanostructure.

In-situ spectroscopic ellipsometry for studies of thin films and membranes

NARCIS (Netherlands)

Ogieglo, Wojciech

2014-01-01

The properties of a thin polymer film can be significantly affected by the presence of a penetrant. It is also known that the behavior of ultra-thin polymer films (<100 nm) may deviate from the bulk behavior. This sole impact of film thickness reduction is often referred to as a nano-confinement

Plasma interactions determine the composition in pulsed laser deposited thin films

Energy Technology Data Exchange (ETDEWEB)

Chen, Jikun; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Laboratory of Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

2014-09-15

Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3}, we demonstrate for as grown La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10{sup −3} mbar and ∼2 × 10{sup −1} mbar. In the intermediate pressure range, La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

Effect of calcination environments and plasma treatment on structural, optical and electrical properties of FTO transparent thin films

Directory of Open Access Journals (Sweden)

Madhav Kafle

2017-07-01

Full Text Available The dependence of the structural, optical and electrical properties of the FTO thin films on the film thickness (276 nm - 546 nm, calcination environment, and low temperature plasma treatment were examined. The FTO thin films, prepared by spray pyrolysis, were calcinated under air followed by either further heat treatment under N2 gas or treatment in low temperature atmospheric plasma. The samples before and after calcination under N2, and plasma treatment will be represented by Sair, SN2 and SPl, respectively, hereafter. The thin films were characterized by measuring the XRD spectra, SEM images, optical transmittance and reflectance, and sheet resistance of the films before and after calcination in N2 environment or plasma treatment. The presence of sharp and narrow multiple peaks in XRD spectra hint us that the films were highly crystalline (polycrystalline. The samples Sair with the thickness of 471 nm showed as high as 92 % transmittance in the visible range. Moreover, from the tauc plot, the optical bandgap Eg values of the Sair found to be noticeably lower than that of the samples SN2. Very surprisingly, the electrical sheet resistance (Rsh found to decrease following the trend as Rshair > RshN2 > RshPl. The samples exposed to plasma found to possess the lowest RshPl (for film with thickness 546 nm, the RshPl was 17 Ω/sq..

Anion-induced N-doping of naphthalenediimide polymer semiconductor in organic thin-film transistors

KAUST Repository

Han, Yang

2018-03-13

Molecular doping is an important strategy to improve the charge transport properties of organic semiconductors in various electronic devices. Compared to p-type dopants, the development of n-type dopants is especially challenging due to poor dopant stability against atmospheric conditions. In this article, we report the n-doping of the milestone naphthalenediimide-based conjugated polymer P(NDI2OD-T2) in organic thin film transistor devices by soluble anion dopants. The addition of the dopants resulted in the formation of stable radical anions in thin films, as confirmed by EPR spectroscopy. By tuning the dopant concentration via simple solution mixing, the transistor parameters could be readily controlled. Hence the contact resistance between the electrodes and the semiconducting polymer could be significantly reduced, which resulted in the transistor behaviour approaching the desirable gate voltage-independent model. Reduced hysteresis was also observed, thanks to the trap filling by the dopant. Under optimal doping concentrations the channel on-current was increased several fold whilst the on/off ratio was simultaneously increased by around one order of magnitude. Hence doping with soluble organic salts appears to be a promising route to improve the charge transport properties of n-type organic semiconductors.

Anion-induced N-doping of naphthalenediimide polymer semiconductor in organic thin-film transistors

KAUST Repository

Han, Yang; Fei, Zhuping; Lin, Yen-Hung; Martin, Jaime; Tuna, Floriana; Anthopoulos, Thomas D.; Heeney, Martin

2018-01-01

Molecular doping is an important strategy to improve the charge transport properties of organic semiconductors in various electronic devices. Compared to p-type dopants, the development of n-type dopants is especially challenging due to poor dopant stability against atmospheric conditions. In this article, we report the n-doping of the milestone naphthalenediimide-based conjugated polymer P(NDI2OD-T2) in organic thin film transistor devices by soluble anion dopants. The addition of the dopants resulted in the formation of stable radical anions in thin films, as confirmed by EPR spectroscopy. By tuning the dopant concentration via simple solution mixing, the transistor parameters could be readily controlled. Hence the contact resistance between the electrodes and the semiconducting polymer could be significantly reduced, which resulted in the transistor behaviour approaching the desirable gate voltage-independent model. Reduced hysteresis was also observed, thanks to the trap filling by the dopant. Under optimal doping concentrations the channel on-current was increased several fold whilst the on/off ratio was simultaneously increased by around one order of magnitude. Hence doping with soluble organic salts appears to be a promising route to improve the charge transport properties of n-type organic semiconductors.

Chemical interaction and adhesion characteristics at the interface of metals (Cu, Ta) and low-k cyclohexane-based plasma polymer (CHexPP) films

International Nuclear Information System (INIS)

Kim, K.J.; Kim, K.S.; Lee, N.-E.; Choi, J.; Jung, D.

2001-01-01

Chemical interaction and adhesion characteristics between metals (Cu, Ta) and low-k plasma-treated cyclohexane-based plasma polymer (CHexPP) films were studied. In order to generate new functional groups that may contribute to the improvement of adhesion between metal and plasma polymer, we performed O 2 , N 2 , and H 2 /He mixture plasma treatment on the surfaces of CHexPP films. Chemical interactions at the interface between metals (Cu, Ta) and plasma-treated CHexPP films were analyzed by x-ray photoelectron spectroscopy. The effect of plasma treatment and thermal annealing on the adhesion characteristics was measured by a tape test and scratch test. The formation of new binding states on the surface of plasma-treated CHexPP films improved adhesion characteristics between metals and CHexPP films. Thermal annealing improves the adhesion property of Cu/CHexPP films, but degrades the adhesion property of Ta/CHexPP films

Development of Functional Thin Polymer Films Using a Layer-by-Layer Deposition Technique.

Science.gov (United States)

Yoshida, Kentaro

2017-01-01

Functional thin films containing insulin were prepared using layer-by-layer (LbL) deposition of insulin and negatively- or positively-charged polymers on the surface of solid substrates. LbL films composed of insulin and negatively-charged polymers such as poly(acrylic acid) (PAA), poly(vinylsulfate) (PVS), and dextran sulfate (DS) were prepared through electrostatic affinity between the materials. The insulin/PAA, insulin/PVS, and insulin/DS films were stable in acidic solutions, whereas they decomposed under physiological conditions as a result of a change in the net electric charge of insulin from positive to negative. Interestingly, the insulin-containing LbL films were stable even in the presence of a digestive-enzyme (pepcin) at pH 1.4 (stomach pH). In contrast, LbL films consisting of insulin and positively-charged polymers such as poly(allylamine hydrochloride) (PAH) decomposed in acidic solutions due to the positive charges of insulin generated in acidic media. The insulin-containing LbL films can be prepared not only on the surface of flat substrates, such as quartz slides, but also on the surface of microparticles, such as poly(lactic acid) (PLA) microbeads. Thus, insulin-containing LbL film-coated PLA microbeads can be handled as a powder. In addition, insulin-containing microcapsules were prepared by coating LbL films on the surface of insulin-doped calcium carbonate (CaCO 3 ) microparticles, followed by dissolution of the CaCO 3 core. The release of insulin from the microcapsules was accelerated at pH 7.4, whereas it was suppressed in acidic solutions. These results suggest the potential use of insulin-containing microcapsules in the development of oral formulations of insulin.

Thin films as an emerging platform for drug delivery

Directory of Open Access Journals (Sweden)

Sandeep Karki

2016-10-01

Full Text Available Pharmaceutical scientists throughout the world are trying to explore thin films as a novel drug delivery tool. Thin films have been identified as an alternative approach to conventional dosage forms. The thin films are considered to be convenient to swallow, self-administrable, and fast dissolving dosage form, all of which make it as a versatile platform for drug delivery. This delivery system has been used for both systemic and local action via several routes such as oral, buccal, sublingual, ocular, and transdermal routes. The design of efficient thin films requires a comprehensive knowledge of the pharmacological and pharmaceutical properties of drugs and polymers along with an appropriate selection of manufacturing processes. Therefore, the aim of this review is to provide an overview of the critical factors affecting the formulation of thin films, including the physico-chemical properties of polymers and drugs, anatomical and physiological constraints, as well as the characterization methods and quality specifications to circumvent the difficulties associated with formulation design. It also highlights the recent trends and perspectives to develop thin film products by various companies.

Hard TiCx/SiC/a-C:H nanocomposite thin films using pulsed high energy density plasma focus device

International Nuclear Information System (INIS)

Umar, Z.A.; Rawat, R.S.; Tan, K.S.; Kumar, A.K.; Ahmad, R.; Hussain, T.; Kloc, C.; Chen, Z.; Shen, L.; Zhang, Z.

2013-01-01

Highlights: •The energetic ions and electron beams are used to synthesize TiC x /SiC/a-C:H films. •As-deposited crystalline and hard nanocomposite TiC x /SiC/a-C:H films are synthesized. •Very high average deposition rates of 68 nm/shot are achieved using dense plasma focus. •The maximum hardness of 22 GPa is achieved at the surface of the film. -- Abstract: Thin films of TiC x /SiC/a-C:H were synthesized on Si substrates using a complex mix of high energy density plasmas and instability accelerated energetic ions of filling gas species, emanated from hot and dense pinched plasma column, in dense plasma focus device. The conventional hollow copper anode of Mather type plasma focus device was replaced by solid titanium anode for synthesis of TiC x /SiC/a-C:H nanocomposite thin films using CH 4 :Ar admixture of (1:9, 3:7 and 5:5) for fixed 20 focus shots as well as with different number of focus shots with fixed CH 4 :Ar admixture ratio 3:7. XRD results showed the formation of crystalline TiC x /SiC phases for thin film synthesized using different number of focus shots with CH 4 :Ar admixture ratio fixed at 3:7. SEM results showed that the synthesized thin films consist of nanoparticle agglomerates and the size of agglomerates depended on the CH 4 :Ar admixture ratio as well as on the number of focus shots. Raman analysis showed the formation of polycrystalline/amorphous Si, SiC and a-C for different CH 4 :Ar ratio as well as for different number of focus shots. The XPS analysis confirmed the formation of TiC x /SiC/a-C:H composite thin film. Nanoindentation results showed that the hardness and elastic modulus values of composite thin films increased with increasing number of focus shots. Maximum values of hardness and elastic modulus at the surface of the composite thin film were found to be about 22 and 305 GPa, respectively for 30 focus shots confirming the successful synthesis of hard composite TiC x /SiC/a-C:H coatings

Reduction of etching damage in lead-zirconate-titanate thin films with inductively coupled plasma

International Nuclear Information System (INIS)

Lim, Kyu-Tae; Kim, Kyoung-Tae; Kim, Dong-Pyo; Kim, Chang-Il

2003-01-01

In this work, we etched lead-zirconate-titanate (PZT) films with various additive gases (O 2 and Ar) in Cl 2 /CF 4 plasmas, while mixing ratio was fixed at 8/2. After the etching, the plasma induced damages are characterized in terms of hysteresis curves, leakage current, retention properties, and switching polarization. When the electrical properties of PZT etched in O 2 or Ar added to Cl 2 /CF 4 were compared, the value of remanent polarization in O 2 added to Cl 2 /CF 4 plasma is higher than that in Ar added plasma. The maximum etch rate of the PZT thin films was 145 nm/min for 30% Ar added Cl 2 /CF 4 gas having mixing ratio of 8/2 and 110 nm/min for 10% O 2 added to that same gas mixture. In order to recover the ferroelectric properties of the PZT thin films after etching, we annealed the etched PZT thin films at 550 deg. C in an O 2 atmosphere for 10 min. From the hysteresis curves, leakage current, retention property, and switching polarization, the reduction of the etching damage and the recovery via the annealing turned out to be more effective when O 2 was added to Cl 2 /CF 4 than Ar. X-ray diffraction showed that the structural damage was lower when O 2 was added to Cl 2 /CF 4 and the improvement in the ferroelectric properties of the annealed samples was consistent with the increased intensities of the (100) and the (200) PZT peaks

Measurements of recombination coefficient of hydrogen atoms on plasma deposited thin films

International Nuclear Information System (INIS)

Drenik, A.; Vesel, A.; Mozetic, M.

2006-01-01

We have performed experiments in plasma afterglow in order to determine the recombination coefficients of plasma deposited thin films of tungsten and graphite. Plasma deposited films rather than bulk material were used in order to more closely emulate surface structure of plasma-facing material deposits in fusion reactors. We have also determined the recombination coefficient of 85250 borosilicate glass and Teflon. Plasma was created by means of a radio frequency generator in a mixture of argon and hydrogen at the pressures between 60 Pa and 280 Pa. The degree of dissociation of hydrogen molecules was found to be between 0.1 and 1. The H-atom density was measured by Fiber Optic Catalytic Probe. The recombination coefficient was determined by measuring the axial profile of the H-atom density and using Smith's side arm diffusion model. (author)

Type of precursor and synthesis of silicon oxycarbide (SiOxCyH) thin films with a surfatron microwave oxygen/argon plasma

International Nuclear Information System (INIS)

Walkiewicz-Pietrzykowska, Agnieszka; Espinos, J. P.; Gonzalez-Elipe, Agustin R.

2006-01-01

Siliconelike thin films (i.e., SiO x C y H z ) were prepared in a microwave plasma enhanced chemical vapor deposition reactor from structurally different organosilicon precursors [i.e., hexamethyldisiloxane (HMDSO), dimethylsilane (DMS), and tetramethylsilane (TMS)]. The films were deposited at room temperature by using different oxygen/argon ratios in the plasma gas. By changing the type of precursor and the relative concentration of oxygen in the plasma, thin films with different compositions (i.e., O/C ratio) and properties are obtained. In general, raising the oxygen concentration in the plasma produces the progressive removal of the organic moieties from the films whose composition and structure then approach those of silicon dioxide. The deposition rate was highly dependent on the type of precursor, following the order HMDSO>>DMS>TMS. The polarizabilities, optical band gaps, and surface free energy of the films also depended on the thin film composition and structure. It is proposed that the Si-O bonds existing in HMDSO is the main factor controlling the distinct reactivity of this precursor and is also responsible for the different compositions and properties of the SiO x C y H z thin films prepared with very low or no oxygen in the plasma gas

Low temperature growth of gallium oxide thin films via plasma enhanced atomic layer deposition

NARCIS (Netherlands)

O'Donoghue, R.; Rechmann, J.; Aghaee, M.; Rogalla, D.; Becker, H.-W.; Creatore, M.; Wieck, A.D.; Devi, A.P.K.

2017-01-01

Herein we describe an efficient low temperature (60–160 °C) plasma enhanced atomic layer deposition (PEALD) process for gallium oxide (Ga2O3) thin films using hexakis(dimethylamido)digallium [Ga(NMe2)3]2 with oxygen (O2) plasma on Si(100). The use of O2 plasma was found to have a significant

Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

Science.gov (United States)

Brown, Ian G.; MacGill, Robert A.; Galvin, James E.; Ogletree, David F.; Salmeron, Miquel

1998-01-01

A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing.

Initial biocompatibility of plasma polymerized hexamethyldisiloxane films with different wettability

Science.gov (United States)

Krasteva, N. A.; Toromanov, G.; Hristova, K. T.; Radeva, E. I.; Pecheva, E. V.; Dimitrova, R. P.; Altankov, G. P.; Pramatarova, L. D.

2010-11-01

Understanding the relationships between material surface properties, behaviour of adsorbed proteins and cellular responses is essential to design optimal material surfaces for tissue engineering. In this study we modify thin layers of plasma polymerized hexamethyldisiloxane (PPHMDS) by ammonia treatment in order to increase surface wettability and the corresponding biological response. The physico-chemical properties of the polymer films were characterized by contact angle (CA) measurements and Fourier Transform Infrared Spectroscopy (FTIR) analysis.Human umbilical vein endothelial cells (HUVEC) were used as model system for the initial biocompatibility studies following their behavior upon preadsorption of polymer films with three adhesive proteins: fibronectin (FN), fibrinogen (FG) and vitronectin (VN). Adhesive interaction of HUVEC was evaluated after 2 hours by analyzing the overall cell morphology, and the organization of focal adhesion contacts and actin cytoskeleton. We have found similar good cellular response on FN and FG coated polymer films, with better pronounced vinculin expression on FN samples while. Conversely, on VN coated surfaces the wettability influenced significantly initial celular interaction spreading. The results obtained suggested that ammonia plasma treatment can modulate the biological activity of the adsorbed protein s on PPHMDS surfaces and thus to influence the interaction with endothelial cells.

Laboratory Analysis of Polymer Thin Films for Planetary Balloons and Gossamer Structures

Science.gov (United States)

Sterling, Jerry; Fairbrother, Debora A.

2004-01-01

Commercially available polymer thin fdms with thickness of 15 microns or less were evaluated for potential application as the gas envelope material of balloons and other inflated vehicles. Films on this thickness scale are of interest for Earth and Mars ballooning as well as many gossamer space structures. Due to the uniqueness of these missions relative to typical uses of these materials, application-specific materials properties measurements were made. We evaluated numerous polymer chemistries, plus a few variations within one chemistry. The data show that there are often trade-offs among the different materials, such as with polyesters and polyimides having greater stiffness (modulus) but lower tear propagation resistance than polyethylene. Sections of polyethylene films can be joined by heat sealing, while adhesives and their accompanying mass penalty must be used with polyesters and polyimides. When the analysis temperature is reduced to 190 K, polyethylenes display dramatically increased stiffness and yield point, while the increase for other materials is more modest. The data also show that manufacturing processes can significantly affect film properties. To emphasize the need for application-specific properties assessment, we discuss two recent applications using these materials.

RESEARCH ON THE ELECTRONIC AND OPTICAL PROPERTIES OF POLYMER AND OTHER ORGANIC MOLECULAR THIN FILMS

Energy Technology Data Exchange (ETDEWEB)

ALEXEI G. VITUKHNOVSKY; IGOR I. SOBELMAN - RUSSIAN ACADEMY OF SCIENCES

1995-09-06

Optical properties of highly ordered films of poly(p-phenylene) (PPP) on different substrates, thin films of mixtures of conjugated polymers, of fullerene and its composition with polymers, molecular J-aggregates of cyanine dyes in frozen matrices have been studied within the framework of the Agreement. Procedures of preparation of high-quality vacuum deposited PPP films on different substrates (ITO, Si, GaAs and etc.) were developed. Using time-correlated single photon counting technique and fluorescence spectroscopy the high quality of PPP films has been confirmed. Dependence of structure and optical properties on the conditions of preparation were investigated. The fluorescence lifetime and spectra of highly oriented vacuum deposited PPP films were studied as a function of the degree of polymerization. It was shown for the first time that the maximum fluorescence quantum yield is achieved for the chain length approximately equal to 35 monomer units. The selective excitation of luminescence of thin films of PPP was performed in the temperature range from 5 to 300 K. The total intensity of luminescence monotonically decreases with decreasing temperature. Conditions of preparation of highly cristallyne fullerene C{sub 60} films by the method of vacuum deposition were found. Composites of C{sub 60} with conjugated polymers PPV and polyacetylene (PA) were prepared. The results on fluorescence quenching, IR and resonant Raman spectroscopy are consistent with earlier reported ultrafast photoinduced electron transfer from PPV to C{sub 60} and show that the electron transfer is absent in the case of the PA-C{sub 60} composition. Strong quenching of PPV fluorescence was observed in the PPV-PA blends. The electron transfer from PPV to PA can be considered as one of the possible mechanisms of this quenching. The dynamics of photoexcitations in different types of J-aggregates of the carbocyanine dye was studied at different temperatures in frozen matrices. The optical

Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion.

Science.gov (United States)

Reis, Rackel; Dumée, Ludovic F; He, Li; She, Fenghua; Orbell, John D; Winther-Jensen, Bjorn; Duke, Mikel C

2015-07-15

Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces.

Osteoblast response to oxygen functionalised plasma polymer surfaces

International Nuclear Information System (INIS)

Kelly, Jonathan M.

2001-01-01

Thin organic films with oxygen-carbon functionalities were deposited from plasmas containing vapour of the small organic compounds: allyI alcohol, methyl vinyl ketone and acrylic acid with octadiene. Characterisation of the deposits was carried out using X-ray photoelectron spectroscopy, in conjunction with chemical derivatisation, and this showed that plasma polymers retained high levels of original monomer functionality when the plasmas were sustained at low power for a given monomer vapour flow rate. High levels of attachment of rat osteosarcoma (ROS 17/2.8) cells were observed on surfaces that had high concentrations of hydroxyl and carbonyl functionalities and intermediate concentrations of carboxyl functionality. Cells did not attach to the octadiene plasma polymer. Cell attachment to carboxyl and methyl functionalised self-assembled monolayers increased with increasing concentration of surface carboxyl groups. Adsorption of the extracellular matrix protein fibronectin to acrylic acid/octadiene plasma copolymers was studied by enzyme linked immunosorbent assays and by I 125 radiolabelling. Fibronectin adsorbed in largest amounts to surfaces with intermediate concentrations of carboxyl functionality. Spreading of ROS cells and rat bone marrow stromal cells (BMSC) was characterised by computer image analysis. Cell spreading in media containing 10% serum, on a surface deposited from a plasma of 5 O/o acrylic acid was much greater than on the octadiene plasma polymer while most extensive cell spreading was observed on these surfaces when preadsorbed with fibronectin. Growth (proliferation) of BMSC was assessed over nine days and was found to be faster on an 50% acrylic acid plasma polymer than on tissue culture polystyrene or a hydrocarbon plasma polymer, though cell growth was fastest on fibronectin precoated substrates. Expression of cellular alkaline phosphatase, collagen and calcium reached similar levels on the 50% acrylic acid plasma polymer, tissue culture

Osteoblast response to oxygen functionalised plasma polymer surfaces

Energy Technology Data Exchange (ETDEWEB)

Kelly, Jonathan M

2001-07-01

Thin organic films with oxygen-carbon functionalities were deposited from plasmas containing vapour of the small organic compounds: allyI alcohol, methyl vinyl ketone and acrylic acid with octadiene. Characterisation of the deposits was carried out using X-ray photoelectron spectroscopy, in conjunction with chemical derivatisation, and this showed that plasma polymers retained high levels of original monomer functionality when the plasmas were sustained at low power for a given monomer vapour flow rate. High levels of attachment of rat osteosarcoma (ROS 17/2.8) cells were observed on surfaces that had high concentrations of hydroxyl and carbonyl functionalities and intermediate concentrations of carboxyl functionality. Cells did not attach to the octadiene plasma polymer. Cell attachment to carboxyl and methyl functionalised self-assembled monolayers increased with increasing concentration of surface carboxyl groups. Adsorption of the extracellular matrix protein fibronectin to acrylic acid/octadiene plasma copolymers was studied by enzyme linked immunosorbent assays and by I{sup 125} radiolabelling. Fibronectin adsorbed in largest amounts to surfaces with intermediate concentrations of carboxyl functionality. Spreading of ROS cells and rat bone marrow stromal cells (BMSC) was characterised by computer image analysis. Cell spreading in media containing 10% serum, on a surface deposited from a plasma of 5 O/o acrylic acid was much greater than on the octadiene plasma polymer while most extensive cell spreading was observed on these surfaces when preadsorbed with fibronectin. Growth (proliferation) of BMSC was assessed over nine days and was found to be faster on an 50% acrylic acid plasma polymer than on tissue culture polystyrene or a hydrocarbon plasma polymer, though cell growth was fastest on fibronectin precoated substrates. Expression of cellular alkaline phosphatase, collagen and calcium reached similar levels on the 50% acrylic acid plasma polymer, tissue

Development of neutron diffuse scattering analysis code by thin film and multilayer film

International Nuclear Information System (INIS)

Soyama, Kazuhiko

2004-01-01

To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering by thin film, roughness of surface of thin film, correlation function, neutron propagation by thin film, diffuse scattering by DWBA theory, measurement model, SDIFFF (neutron diffuse scattering analysis program by thin film) and simulation results are explained. On neutron diffuse scattering by multilayer film, roughness of multilayer film, principle of diffuse scattering, measurement method and simulation examples by MDIFF (neutron diffuse scattering analysis program by multilayer film) are explained. (S.Y.)To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering

Characteristics of indirect laser-induced plasma from a thin film of oil on a metallic substrate

Science.gov (United States)

Xiu, Jun-Shan; Bai, Xue-Shi; Motto-Ros, Vincent; Yu, Jin

2015-04-01

Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that Al emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0 μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.

Selective metallization of amorphous-indium-gallium-zinc-oxide thin-film transistor by using helium plasma treatment

Science.gov (United States)

Jang, Hun; Lee, Su Jeong; Porte, Yoann; Myoung, Jae-Min

2018-03-01

In this study, the effects of helium (He) plasma treatment on amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) have been investigated. The He plasma treatment induced a dramatic decrease of the resistivity in a-IGZO thin films from 1.25 × 106 to 5.93 mΩ cm. After 5 min He plasma treatment, the a-IGZO films showed an increase in carrier concentration to 6.70 × 1019 cm-3 combined with a high hall mobility of 15.7 cm2 V-1 s-1. The conductivity improvement was linked to the formation of oxygen vacancies during the He plasma treatment, which was observed by x-ray photoelectron spectroscopy analysis. The a-IGZO films did not appear to be damaged on the surface following the plasma treatment and showed a high transmittance of about 88.3% at a wavelength of 550 nm. The He plasma-treated a-IGZO films were used as source/drain (S/D) electrodes in a-IGZO TFTs. The devices demonstrated promising characteristics, on pair with TFTs using Al electrodes, with a threshold voltage (V T) of -1.97 V, sub-threshold slope (SS) of 0.52 V/decade, saturation mobility (μ sat) of 8.75 cm2 V-1 s-1, and on/off current ratio (I on/I off) of 2.66 × 108.

Thin films of thermoelectric compound Mg2Sn deposited by co-sputtering assisted by multi-dipolar microwave plasma

International Nuclear Information System (INIS)

Le-Quoc, H.; Lacoste, A.; Hlil, E.K.; Bes, A.; Vinh, T. Tan; Fruchart, D.; Skryabina, N.

2011-01-01

Highlights: → Mg 2 Sn thin films deposited by plasma co-sputtering, on silicon and glass substrates. → Formation of nano-grained polycrystalline films on substrates at room temperature. → Structural properties vary with target biasing and target-substrate distance. → Formation of the hexagonal phase of Mg 2 Sn in certain deposition conditions. → Power factor ∼5.0 x 10 -3 W K -2 m -1 for stoichiometric Mg 2 Sn films doped with ∼1 at.% Ag. - Abstract: Magnesium stannide (Mg 2 Sn) thin films doped with Ag intended for thermoelectric applications are deposited on both silicon and glass substrates at room temperature by plasma assisted co-sputtering. Characterization by scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction confirms the formation of fine-grained polycrystalline thin films with thickness of 1-3 μm. Stoichiometry, microstructure and crystal structure of thin films are found to vary with target biasing and the distance from targets to substrate. Measurements of electrical resistivity and Seebeck coefficient at room temperature show the maximum power factor of ∼5.0 x 10 -3 W K -2 m -1 for stoichiometric Mg 2 Sn thin films doped with ∼1 at.% Ag.

Uniform GaN thin films grown on (100) silicon by remote plasma atomic layer deposition

International Nuclear Information System (INIS)

Shih, Huan-Yu; Chen, Miin-Jang; Lin, Ming-Chih; Chen, Liang-Yih

2015-01-01

The growth of uniform gallium nitride (GaN) thin films was reported on (100) Si substrate by remote plasma atomic layer deposition (RP-ALD) using triethylgallium (TEG) and NH 3 as the precursors. The self-limiting growth of GaN was manifested by the saturation of the deposition rate with the doses of TEG and NH 3 . The increase in the growth temperature leads to the rise of nitrogen content and improved crystallinity of GaN thin films, from amorphous at a low deposition temperature of 200 °C to polycrystalline hexagonal structures at a high growth temperature of 500 °C. No melting-back etching was observed at the GaN/Si interface. The excellent uniformity and almost atomic flat surface of the GaN thin films also infer the surface control mode of the GaN thin films grown by the RP-ALD technique. The GaN thin films grown by RP-ALD will be further applied in the light-emitting diodes and high electron mobility transistors on (100) Si substrate. (paper)

High performance solution-deposited amorphous indium gallium zinc oxide thin film transistors by oxygen plasma treatment

KAUST Repository

Nayak, Pradipta K.

2012-05-16

Solution-deposited amorphous indium gallium zinc oxide (a-IGZO) thin film transistors(TFTs) with high performance were fabricated using O2-plasma treatment of the films prior to high temperature annealing. The O2-plasma treatment resulted in a decrease in oxygen vacancy and residual hydrocarbon concentration in the a-IGZO films, as well as an improvement in the dielectric/channel interfacial roughness. As a result, the TFTs with O2-plasma treated a-IGZO channel layers showed three times higher linear field-effect mobility compared to the untreated a-IGZO over a range of processing temperatures. The O2-plasma treatment effectively reduces the required processing temperature of solution-deposited a-IGZO films to achieve the required performance.

Resistive switching of organic–inorganic hybrid devices of conductive polymer and permeable ultra-thin SiO2 films

Science.gov (United States)

Yamamoto, Shunsuke; Kitanaka, Takahisa; Miyashita, Tokuji; Mitsuishi, Masaya

2018-06-01

We propose a resistive switching device composed of conductive polymer (PEDOT:PSS) and SiO2 ultra-thin films. The SiO2 film was fabricated from silsesquioxane polymer nanosheets as a resistive switching layer. Devices with metal (Ag or Au)∣SiO2∣PEDOT:PSS architecture show good resistive switching performance with set–reset voltages as low as several hundred millivolts. The device properties and the working mechanism were investigated by varying the electrode material, surrounding atmosphere, and SiO2 film thickness. Results show that resistive switching is based on water and ion migration at the PEDOT:PSS∣SiO2 interface.

Analysis of Hard Thin Film Coating

Science.gov (United States)

Shen, Dashen

1998-01-01

MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

Comparison study of ITO thin films deposited by sputtering at room temperature onto polymer and glass substrates

International Nuclear Information System (INIS)

Guillen, C.; Herrero, J.

2005-01-01

Indium tin oxide (ITO) thin films have been grown simultaneously onto glass and polymer substrates at room temperature by sputtering from ceramic target. The structure, morphology and electro-optical characteristics of the ITO/glass and ITO/polymer samples have been analyzed by X-ray diffraction, atomic force microscopy, four-point electrical measurements and spectrophotometry. In the selected experimental conditions, the polycrystalline ITO coating shows higher average grain size and higher conductivity, with similar visible transmittance, onto the polymer than onto the glass substrate

Thin film ceramic thermocouples

Science.gov (United States)

Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

2011-01-01

A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

Nanoparticles Stabilize Thin Polymer Films: A Fundamental Study to Understand the Phenomenon

Energy Technology Data Exchange (ETDEWEB)

Michael E. Mackay

2009-03-04

A new understanding of thermodynamics at the nanoscale resulted in a recently discovered first order phase transition that nanoparticles in a polymer film will all segregate to the supporting substrate. This is an unusual phase transition that was predicted using a modeling technique developed at Sandia National Laboratories and required the equivalent of many computational years on one computer. This project is a collaboration between Prof. Michael Mackay's group and Dr. Amalie Frischknecht (Sandia National Laboratories) where experimental observation and theoretical rationalization and prediction are brought together. Other discoveries were that this phase transition could be avoided by changing the nanoparticle properties yielding control of the assembly process at the nanoscale. In fact, the nanoparticles could be made to assemble to the supporting substrate, to the air interface or not assemble at all within a thin polymer film of order 100 nm in thickness. However, when the assembly process is present it is so robust that it is possible to make rough liquid films at the nanoscale due to nanoparticles assembling around three-dimensional objects. From this knowledge we are able to design and manufacture new coatings with particular emphasis on polymer-based solar cells. Careful control of the morphology at the nanoscale is expected to provide more efficient devices since the physics of these systems is dictated at this length scale and assembly of nanoparticles to various interfaces is critical to operation.

Self-destruction and dewetting of thin polymer films the role of interfacial tensions

CERN Document Server

Reiter, G; Sharma, A

2003-01-01

We present real-time optical microscopy observations of the pattern evolution in self-destruction and subsequent dewetting of thin polymer films based on experiments with polydimethylsiloxane films sandwiched between silicon wafers and aqueous surfactant solutions. A clear scenario consisting of four distinct stages has been identified: amplification of surface fluctuations, break-up of the film and formation of holes, growth and coalescence of holes, and droplet formation and ripening. Besides a linear dependence on film viscosity and surface tension, the time tau for film rupture varied significantly with film thickness h (tau approx h sup 5), as expected from theory. While the role of long-range forces is dominant only in the first stage, the later stages are controlled by the combination of interfacial tensions resulting in the contact angle characterizing the three-phase contact line. During the first stage, the characteristic distance of the pattern remains constant, represented by a time-independent wa...

Thin film silicon by a microwave plasma deposition technique: Growth and devices, and, interface effects in amorphous silicon/crystalline silicon solar cells

Science.gov (United States)

Jagannathan, Basanth

Thin film silicon (Si) was deposited by a microwave plasma CVD technique, employing double dilution of silane, for the growth of low hydrogen content Si films with a controllable microstructure on amorphous substrates at low temperatures (prepared by this technique. Such films showed a dark conductivity ˜10sp{-6} S/cm, with a conduction activation energy of 0.49 eV. Film growth and properties have been compared for deposition in Ar and He carrier systems and growth models have been proposed. Low temperature junction formation by undoped thin film silicon was examined through a thin film silicon/p-type crystalline silicon heterojunctions. The thin film silicon layers were deposited by rf glow discharge, dc magnetron sputtering and microwave plasma CVD. The hetero-interface was identified by current transport analysis and high frequency capacitance methods as the key parameter controlling the photovoltaic (PV) response. The effect of the interface on the device properties (PV, junction, and carrier transport) was examined with respect to modifications created by chemical treatment, type of plasma species, their energy and film microstructure interacting with the substrate. Thermally stimulated capacitance was used to determine the interfacial trap parameters. Plasma deposition of thin film silicon on chemically clean c-Si created electron trapping sites while hole traps were seen when a thin oxide was present at the interface. Under optimized conditions, a 10.6% efficient cell (11.5% with SiOsb2 A/R) with an open circuit voltage of 0.55 volts and a short circuit current density of 30 mA/cmsp2 was fabricated.

Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

Energy Technology Data Exchange (ETDEWEB)

Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

2010-10-01

In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

Crack density and electrical resistance in indium-tin-oxide/polymer thin films under cyclic loading

KAUST Repository

Mora Cordova, Angel

2014-11-01

Here, we propose a damage model that describes the degradation of the material properties of indium-tin-oxide (ITO) thin films deposited on polymer substrates under cyclic loading. We base this model on our earlier tensile test model and show that the new model is suitable for cyclic loading. After calibration with experimental data, we are able to capture the stress-strain behavior and changes in electrical resistance of ITO thin films. We are also able to predict the crack density using calibrations from our previous model. Finally, we demonstrate the capabilities of our model based on simulations using material properties reported in the literature. Our model is implemented in the commercially available finite element software ABAQUS using a user subroutine UMAT.[Figure not available: see fulltext.].

Plasma-assisted co-evaporation of {beta}-indium sulfide thin films

Energy Technology Data Exchange (ETDEWEB)

Kosaraju, Sreenivas; Marino, Joseph A.; Harvey, John A.; Wolden, Colin A. [Department of Chemical Engineering, Colorado School of Mines, Golden, CO 80401 (United States)

2006-05-05

This paper describes the development of plasma-assisted co-evaporation (PACE) for the formation of {beta}-In{sub 2}S{sub 3} thin films. Indium was supplied by conventional thermal evaporation, while the chalcogen gas precursor (H{sub 2}S) was activated using an inductively coupled plasma (ICP) source. Using a combination of optical emission spectroscopy and mass spectrometry it was shown that the ICP effectively dissociated H{sub 2}S, producing atomic sulfur. Transport modeling was used to quantify the flux distributions of the co-evaporated metal and the plasma-generated species impinging the substrate. Model predictions were validated by measurements of deposition rate and film properties. Substantial improvements in both materials utilization and substrate temperature reduction were realized with respect to conventional co-evaporation. {beta}-In{sub 2}S{sub 3} was formed as low as 100{sup o}C and it was observed that quality was a strong function of S/In ratio. The grain size decreased and the optical band gap increased as the substrate temperature was reduced. (author)

Improved Adhesion of Gold Thin Films Evaporated on Polymer Resin: Applications for Sensing Surfaces and MEMS

Directory of Open Access Journals (Sweden)

Behrang Moazzez

2013-05-01

Full Text Available We present and analyze a method to improve the morphology and mechanical properties of gold thin films for use in optical sensors or other settings where good adhesion of gold to a substrate is of importance and where controlled topography/roughness is key. To improve the adhesion of thermally evaporated gold thin films, we introduce a gold deposition step on SU-8 photoresist prior to UV exposure but after the pre-bake step of SU-8 processing. Shrinkage and distribution of residual stresses, which occur during cross-linking of the SU-8 polymer layer in the post-exposure baking step, are responsible for the higher adhesion of the top gold film to the post-deposition cured SU-8 sublayer. The SU-8 underlayer can also be used to tune the resulting gold film morphology. Our promoter-free protocol is easily integrated with existing sensor microfabrication processes.

Properties of CuS thin films treated in air plasma

International Nuclear Information System (INIS)

Rodriguez-Lazcano, Y.; Martinez, H.; Calixto-Rodriguez, M.; Nunez Rodriguez, A.

2009-01-01

Copper sulfide thin films were grown by chemical deposition and post treated in air plasma during 20 min. Air plasma was generated by alternating current discharge at a pressure of 4 x 10 2 Pa. The power discharge was maintained at an output of 220 V and a current of 0.2 A. Thermal annealing at 300 o C was performed for comparison. X-ray diffraction shows that plasma treatment results in phase transformation of Cu 39 S 28 (as grown) to CuS (treated by plasma). The copper lost is confirmed by X-ray fluorescence. No significant change in the optical band gap was observed due to plasma action. In addition, the electrical conductivity increases in one order of magnitude. On the other hand, the samples under plasma condition show a parallel growth to the substrate and an increase in the surface uniformity. The plasma etching removes copper due to its affinity with oxygen to form CuO, as is corroborated by optical emission spectroscopy.

Electrical four-point probing of spherical metallic thin films coated onto micron sized polymer particles

Energy Technology Data Exchange (ETDEWEB)

Pettersen, Sigurd R., E-mail: sigurd.r.pettersen@ntnu.no, E-mail: jianying.he@ntnu.no; Stokkeland, August Emil; Zhang, Zhiliang; He, Jianying, E-mail: sigurd.r.pettersen@ntnu.no, E-mail: jianying.he@ntnu.no [NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Kristiansen, Helge [NTNU Nanomechanical Lab, Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim (Norway); Conpart AS, Dragonveien 54, NO-2013 Skjetten (Norway); Njagi, John; Goia, Dan V. [Center for Advanced Materials Processing, Clarkson University, Potsdam, New York 13699-5814 (United States); Redford, Keith [Conpart AS, Dragonveien 54, NO-2013 Skjetten (Norway)

2016-07-25

Micron-sized metal-coated polymer spheres are frequently used as filler particles in conductive composites for electronic interconnects. However, the intrinsic electrical resistivity of the spherical thin films has not been attainable due to deficiency in methods that eliminate the effect of contact resistance. In this work, a four-point probing method using vacuum compatible piezo-actuated micro robots was developed to directly investigate the electric properties of individual silver-coated spheres under real-time observation in a scanning electron microscope. Poly(methyl methacrylate) spheres with a diameter of 30 μm and four different film thicknesses (270 nm, 150 nm, 100 nm, and 60 nm) were investigated. By multiplying the experimental results with geometrical correction factors obtained using finite element models, the resistivities of the thin films were estimated for the four thicknesses. These were higher than the resistivity of bulk silver.

Polymer relaxations in thin films in the vicinity of a penetrant or a temperature induced glass transition

NARCIS (Netherlands)

Ogieglo, Wojciech; Wessling, Matthias; Benes, Nieck Edwin

2014-01-01

The transient properties of thin glassy polymer films in the vicinity of the glass transition are investigated. We compare the differences and similarities between sorption and temperature induced glass transitions, referred to as Pg and Tg, respectively. The experimental technique used is in situ

Prediction of crack density and electrical resistance changes in indium tin oxide/polymer thin films under tensile loading

KAUST Repository

Mora Cordova, Angel; Khan, Kamran; El Sayed, Tamer

2014-01-01

We present unified predictions for the crack onset strain, evolution of crack density, and changes in electrical resistance in indium tin oxide/polymer thin films under tensile loading. We propose a damage mechanics model to quantify and predict

Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

Directory of Open Access Journals (Sweden)

Sanju Gupta

2015-10-01

Full Text Available Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO1, (PPy/ErGO1, (PAni/GO1 and (PPy/GO1. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, Cs, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent Cs of ≥350 F g−1 as compared with constituents (∼70 F g−1 at discharge current density of 0.3 A g−1 that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting and conducting polymers (semiconducting backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine electrochemical (reactivity of surface ion

Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

Energy Technology Data Exchange (ETDEWEB)

Gupta, Sanju, E-mail: sanju.gupta@wku.edu; Price, Carson [Department of Physics and Astronomy, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY 42101-3576 (United States)

2015-10-15

Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL) assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO){sub 1}, (PPy/ErGO){sub 1}, (PAni/GO){sub 1} and (PPy/GO){sub 1}. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS) with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, C{sub s}, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent C{sub s} of ≥350 F g{sup −1} as compared with constituents (∼70 F g{sup −1}) at discharge current density of 0.3 A g{sup −1} that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM) technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting) and conducting polymers (semiconducting) backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine

Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

Science.gov (United States)

Gupta, Sanju; Price, Carson

2015-10-01

Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL) assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO)1, (PPy/ErGO)1, (PAni/GO)1 and (PPy/GO)1. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS) with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, Cs, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent Cs of ≥350 F g-1 as compared with constituents (˜70 F g-1) at discharge current density of 0.3 A g-1 that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM) technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting) and conducting polymers (semiconducting) backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine electrochemical (re)activity of surface ion adsorption sites

In situ preparation of biomimetic thin films and their surface-shielding effect for organisms in high vacuum.

Directory of Open Access Journals (Sweden)

Hiroshi Suzuki

Full Text Available Self-standing biocompatible films have yet to be prepared by physical or chemical vapor deposition assisted by plasma polymerization because gaseous monomers have thus far been used to create only polymer membranes. Using a nongaseous monomer, we previously found a simple fabrication method for a free-standing thin film prepared from solution by plasma polymerization, and a nano-suit made by polyoxyethylene (20 sorbitan monolaurate can render multicellular organisms highly tolerant to high vacuum. Here we report thin films prepared by plasma polymerization from various monomer solutions. The films had a flat surface at the irradiated site and were similar to films produced by vapor deposition of gaseous monomers. However, they also exhibited unique characteristics, such as a pinhole-free surface, transparency, solvent stability, flexibility, and a unique out-of-plane molecular density gradient from the irradiated to the unirradiated surface of the film. Additionally, covering mosquito larvae with the films protected the shape of the organism and kept them alive under the high vacuum conditions in a field emission-scanning electron microscope. Our method will be useful for numerous applications, particularly in the biological sciences.

The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers

Science.gov (United States)

Hsu, Yu-Jen

Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by

Brush-Coated Nanoparticle Polymer Thin Films: structure-mechanical-optical properties

Energy Technology Data Exchange (ETDEWEB)

Green, Peter F. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

2014-08-15

Our work was devoted to understanding the structure and properties of a class of thin film polymer nanocomposites (PNCs). PNCs are composed of polymer hosts into which nanoparticles (metallic nanoparticles, quantum dots, nanorods, C₆₀, nanotubes) are incorporated. PNCs exhibit a diverse range of functional properties (optical, electronic, mechanical, biomedical, structural), determined in part by the chemical composition of the polymer host and the type of nanoparticle. The properties PNCs rely not only on specific functional, size-dependent, behavior of the nanoparticles, but also on the dispersion, and organizational order in some cases, inter-nanoparticle separation distances, and on relative interactions between the nanoparticles and the host. Therefore the scientific challenges associated with understanding the interrelations between the structure and function/properties of PNCs are far more complex than may be understood based only on the knowledge of the compositions of the constituents. The challenges of understanding the structure-function behavior of PNCs are further compounded by the fact that control of the dispersion of the nanoparticles within the polymer hosts is difficult; one must learn how to disperse inorganic particles within an organic host. The goal of this proposal was to develop an understanding of the connection between the structure and the thermal (glass transition), mechanical and optical properties of a specific class of PNCs. Specifically PNCs composed of polymer chain grafted gold nanoparticles within polymer hosts. A major objective was to understand how to develop basic principles that enable the fabrication of functional materials possessing optimized morphologies and combinations of materials properties.

Molecular Orientation of Conjugated Polymer Chains in Nanostructures and Thin Films: Review of Processes and Application to Optoelectronics

Directory of Open Access Journals (Sweden)

Varun Vohra

2017-01-01

Full Text Available Semiconducting polymers are composed of elongated conjugated polymer backbones and side chains with high solubility and mechanical properties. The combination of these two features results in a high processability and a potential to orient the conjugated backbones in thin films and nanofibers. The thin films and nanofibers are usually composed of highly crystalline (high charge transport and amorphous parts. Orientation of conjugated polymer can result in enhanced charge transport or optical properties as it induces increased crystallinity or preferential orientation of the crystallites. After summarizing the potential strategies to exploit molecular order in conjugated polymer based optoelectronic devices, we will review some of the fabrication processes to induce molecular orientation. In particular, we will review the cases involving molecular and interfacial interactions, unidirectional deposition processes, electrospinning, and postdeposition mechanical treatments. The studies presented here clearly demonstrate that process-controlled molecular orientation of the conjugated polymer chains can result in high device performances (mobilities over 40 cm2·V−1·s−1 and solar cells with efficiencies over 10%. Furthermore, the peculiar interactions between molecularly oriented polymers and polarized light have the potential not only to generate low-cost and low energy consumption polarized light sources but also to fabricate innovative devices such as solar cell integrated LCDs or bipolarized LEDs.

Surface tailoring of newly developed amorphous Znsbnd Sisbnd O thin films as electron injection/transport layer by plasma treatment: Application to inverted OLEDs and hybrid solar cells

Science.gov (United States)

Yang, Hongsheng; Kim, Junghwan; Yamamoto, Koji; Xing, Xing; Hosono, Hideo

2018-03-01

We report a unique amorphous oxide semiconductor Znsbnd Sisbnd O (a-ZSO) which has a small work function of 3.4 eV for as-deposited films. The surface modification of a-ZSO thin films by plasma treatments is examined to apply it to the electron injection/transport layer of organic devices. It turns out that the energy alignment and exciton dissociation efficiency at a-ZSO/organic semiconductor interface significantly changes by choosing different gas (oxygen or argon) for plasma treatments (after a-ZSO was exposed to atmospheric environment for 5 days). In situ ultraviolet photoelectron spectroscopy (UPS) measurement reveals that the work function of a-ZSO is increased to 4.0 eV after an O2-plasma treatment, while the work function of 3.5 eV is recovered after an Ar-plasma treatment which indicates this treatment is effective for surface cleaning. To study the effects of surface treatments to device performance, OLEDs and hybrid polymer solar cells with O2-plasma or Ar-plasma treated a-ZSO are compared. Effects of these surface treatments on performance of inverted OLEDs and hybrid polymer solar cells are examined. Ar-plasma treated a-ZSO works well as the electron injection layer in inverted OLEDs (Alq3/a-ZSO) because the injection barrier is small (∼ 0.1 eV). On the other hands, O2-plasma treated a-ZSO is more suitable for application to hybrid solar cells which is benefiting from higher exciton dissociation efficiency at polymer (P3HT)/ZSO interface.

Effect of ablation geometry on the dynamics, composition, and geometrical shape of thin film plasma

Science.gov (United States)

Mondal, Alamgir; Singh, R. K.; Kumar, Ajai

2018-01-01

The characteristics of plasma plume produced by front and back ablation of thin films have been investigated using fast imaging and optical emission spectroscopy. Ablation geometry dependence of the plume dynamics, its geometrical aspect and composition is emphasized. Also, the effect of an ambient environment and the beam diameter of an ablating laser on the front and back ablations is briefly discussed. Analysis of time resolved images and plasma parameters indicates that the energetic and spherical plasma formed by front ablation is strikingly different in comparison to the slow and nearly cylindrical plasma plume observed in the case of back ablation. Further shock formation, plume confinement, thermalization and validity of different expansion models in these two ablation geometries are also presented. The present study demonstrates the manipulation of kinetic energy, shape, ion/neutral compositions and directionality of the expanding plume by adjusting the experimental configuration, which is highly relevant to its utilization in various applications e.g., generation of energetic particles, tokamak edge plasma diagnostics, thin film deposition, etc.

ITO films deposited by rf-PERTE on unheated polymer substrates--properties dependence on In-Sn alloy composition

International Nuclear Information System (INIS)

Nunes de Carvalho, C.; Lavareda, G.; Fortunato, E.; Vilarinho, P.; Amaral, A.

2004-01-01

The study of the influence of different tin concentrations in the In-Sn alloy on the properties of indium tin oxide (ITO) thin films deposited by radio frequency (rf) plasma enhanced reactive thermal evaporation (rf-PERTE) onto flexible polymer and window glass substrates at room temperature is presented. The polymer substrate used is polyethylene terephthalate (PET). The tin concentration in the source alloy varied in the range 5-20 wt.%. The average thickness of the ITO films is of about 90 nm. Results show that ITO thin films deposited on PET from the evaporation of a 85%In:15%Sn alloy exhibit the following characteristics: an average visible transmittance of 80% and an electrical resistivity of 1.6x10 -3 Ω cm. On glass the value of the average visible transmittance increases (85%) and the resistivity decreases to 7.6x10 -4 Ω cm. The electrical properties of ITO films on PET are largely affected by the low carrier mobility

Dewetting of polymer thin films on modified curved surfaces: preparation of polymer nanoparticles with asymmetric shapes by anodic aluminum oxide templates.

Science.gov (United States)

Liu, Chih-Ting; Tsai, Chia-Chan; Chu, Chien-Wei; Chi, Mu-Huan; Chung, Pei-Yun; Chen, Jiun-Tai

2018-04-18

We study the dewetting behaviors of poly(methyl methacrylate) (PMMA) thin films coated in the cylindrical nanopores of anodic aluminum oxide (AAO) templates by thermal annealing. Self-assembled monolayers (SAMs) of n-octadecyltrichlorosilane (ODTS) are introduced to modify the pore surfaces of the AAO templates to induce the dewetting process. By using scanning electron microscopy (SEM), the dewetting-induced morphology transformation from the PMMA thin films to PMMA nanoparticles with asymmetric shapes can be observed. The sizes of the PMMA nanoparticles can be controlled by the original PMMA solution concentrations. The dewetting phenomena on the modified nanopores are explained by taking into account the excess intermolecular interaction free energy (ΔG). This work opens a new possibility for creating polymer nanoparticles with asymmetric shapes in confined geometries.

Thin films of metal-organic compounds and metal nanoparticle

Indian Academy of Sciences (India)

Thin films of metal-organic compounds and metal nanoparticle-embedded polymers for nonlinear optical applications. S Philip Anthony Shatabdi Porel D ... Thin films based on two very different metal-organic systems are developed and some nonlinear optical applications are explored. A family of zinc complexes which ...

Electromagnetic shielding effectiveness of a thin silver layer deposited onto PET film via atmospheric pressure plasma reduction

Science.gov (United States)

Oh, Hyo-Jun; Dao, Van-Duong; Choi, Ho-Suk

2018-03-01

This study presents the first use of a plasma reduction reaction under atmospheric pressure to fabricate a thin silver layer on polyethylene terephthalate (PET) film without the use of toxic chemicals, high voltages, or an expensive vacuum apparatus. The developed film is applied to electromagnetic interference (EMI) shielding. After repeatedly depositing a silver layer through a plasma reduction reaction on PET, we can successfully fabricate a uniformly deposited thin silver layer. It was found that both the particle size and film thickness of thin silver layers fabricated at different AgNO3 concentrations increase with an increase in the concentration of AgNO3. However, the roughness of the thin silver layer decreases when increasing the concentration of AgNO3 from 100 to 500 mM, and the roughness increases with a further increase in the concentration of AgNO3. The EMI shielding effectiveness (SE) of the film is measured in the frequency range of 0.045 to 1 GHz. As a result of optimizing the electrical conductivity by measuring sheet resistance of the thin silver layer, the film fabricated from 500 mM AgNO3 exhibits the highest EMI SE among all fabricated films. The maximum values of the EMI SE are 60.490 dB at 0.1 GHz and 54.721 dB at 1.0 GHz with minimum sheet resistance of 0.244 Ω/□. Given that the proposed strategy is simple and effective, it is promising for fabricating various low-cost metal films with high EMI SE.

Synthesis of Thin Film Composite Metal-Organic Frameworks Membranes on Polymer Supports

KAUST Repository

Barankova, Eva

2017-06-01

Since the discovery of size-selective metal-organic frameworks (MOF) researchers have tried to manufacture them into gas separation membranes. ZIF-8 became the most studied MOF for membrane applications mainly because of its simple synthesis, good chemical and thermal stability, recent commercial availability and attractive pore size. The aim of this work is to develop convenient methods for growing ZIF thin layers on polymer supports to obtain defect-free ZIF membranes with good gas separation properties. We present new approaches for ZIF membranes preparation on polymers. We introduce zinc oxide nanoparticles in the support as a secondary metal source for ZIF-8 growth. Initially the ZnO particles were incorporated into the polymer matrix and later on the surface of the polymer by magnetron sputtering. In both cases, the ZnO facilitated to create more nucleation opportunities and improved the ZIF-8 growth compared to the synthesis without using ZnO. By employing the secondary seeded growth method, we were able to obtain thin (900 nm) ZIF-8 layer with good gas separation performance. Next, we propose a metal-chelating polymer as a suitable support for growing ZIF layers. Defect-free ZIF-8 films with a thickness of 600 nm could be obtained by a contra-diffusion method. ZIF-8 membranes were tested for permeation of hydrogen and hydrocarbons, and one of the highest selectivities reported so far for hydrogen/propane, and propylene/propane was obtained. Another promising method to facilitate the growth of MOFs on polymeric supports is the chemical functionalization of the support surface with functional groups, which can complex metal ions and which can covalently bond the MOF crystals. We functionalized the surface of a common porous polymeric membrane with amine groups, which took part in the reaction to form ZIF-8 nanocrystals. We observed an enhancement in adhesion between the ZIF layer and the support. The effect of parameters of the contra-diffusion experiment

Solution-processed small molecule-polymer blend organic thin-film transistors with hole mobility greater than 5 cm 2/Vs

KAUST Repository

Smith, Jeremy N.; Zhang, Weimin; Sougrat, Rachid; Zhao, Kui; Li, Ruipeng; Cha, Dong Kyu; Amassian, Aram; Heeney, Martin J.; McCulloch, Iain A.; Anthopoulos, Thomas D.

2012-01-01

Using phase-separated organic semiconducting blends containing a small molecule, as the hole transporting material, and a conjugated amorphous polymer, as the binder material, we demonstrate solution-processed organic thin-film transistors with superior performance characteristics that include; hole mobility >5 cm 2/Vs, current on/off ratio ≥10 6 and narrow transistor parameter spread. These exceptional characteristics are attributed to the electronic properties of the binder polymer and the advantageous nanomorphology of the blend film. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solution-processed small molecule-polymer blend organic thin-film transistors with hole mobility greater than 5 cm 2/Vs

KAUST Repository

Smith, Jeremy N.

2012-04-10

Using phase-separated organic semiconducting blends containing a small molecule, as the hole transporting material, and a conjugated amorphous polymer, as the binder material, we demonstrate solution-processed organic thin-film transistors with superior performance characteristics that include; hole mobility >5 cm 2/Vs, current on/off ratio ≥10 6 and narrow transistor parameter spread. These exceptional characteristics are attributed to the electronic properties of the binder polymer and the advantageous nanomorphology of the blend film. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

WO.sub.3./sub. thin films prepared by sedimentation and plasma sputtering

Czech Academy of Sciences Publication Activity Database

Olejníček, Jiří; Brunclíková, Michaela; Kment, Š.; Hubička, Zdeněk; Kmentová, N.; Kšírová, Petra; Čada, Martin; Zlámal, M.; Krýsa, J.

2017-01-01

Roč. 318, Jun (2017), s. 281-288 ISSN 1385-8947 R&D Projects: GA TA ČR(CZ) TF01000084; GA ČR(CZ) GA15-00863S; GA TA ČR TA03010743; GA ČR GAP108/12/2104 Institutional support: RVO:68378271 Keywords : WO 3 * thin films * water splitting * pulsed magnetron sputtering * sedimentation * photo-electro-chemistry Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 6.216, year: 2016

Antibacterial effects of silver-doped hydroxyapatite thin films sputter deposited on titanium

International Nuclear Information System (INIS)

Trujillo, Nathan A.; Oldinski, Rachael A.; Ma, Hongyan; Bryers, James D.; Williams, John D.; Popat, Ketul C.

2012-01-01

Since many orthopedic implants fail as a result of loosening, wear, and inflammation caused by repeated loading on the joints, coatings such as hydroxyapatite (HAp) on titanium with a unique topography have been shown to improve the interface between the implant and the natural tissue. Another serious problem with long-term or ideally permanent implants is infection. It is important to prevent initial bacterial colonization as existing colonies have the potential to become encased in an extracellular matrix polymer (biofilm) that is resistant to antibacterial agents. In this study, plasma-based ion implantation was used to examine the effects of pre-etching on plain titanium. Topographical changes to the titanium samples were examined and compared via scanning electron microscopy. Hydroxyapatite and silver-doped hydroxyapatite thin films were then sputter deposited on titanium substrates etched at − 700 eV. For silver-doped films, two concentrations of silver (∼ 0.5 wt.% and ∼ 1.5 wt.%) were used. Silver concentrations in the film were determined using energy dispersive X-ray spectroscopy. Hydroxyapatite film thicknesses were determined by measuring the surface profile using contact profilometry. Staphylococcus epidermidis and Pseudomonas aeruginosa adhesion studies were performed on plain titanium, titanium coated with hydroxyapatite, titanium coated with ∼ 0.5 wt.% silver-doped hydroxyapatite, and titanium coated with ∼ 1.5 wt.% silver-doped hydroxyapatite. Results indicate that less bacteria adhered to surfaces containing hydroxyapatite and silver; further, as the hydroxyapatite films delaminated, silver ions were released which killed bacteria in suspension. - Highlights: ► We have developed a combination of plasma-based ion implantation and ion beam sputter deposition technique. ► Silver-doped hydroxyapatite thin films on titanium were developed. ► The thin films showed the ability to control the concentration of silver that is doped within the

Photoluminescence Spectroscopy of Rhodamine 800 Aqueous Solution and Dye-Doped Polymer Thin-Film: Concentration and Solvent Effects

Science.gov (United States)

Le, Khai Q.; Dang, Ngo Hai

2018-05-01

This paper investigates solvent and concentration effects on photoluminescence (PL) or fluorescence properties of Rhodamine 800 (Rho800) dyes formed in aqueous solution and polymer thin-film. Various commonly used organic solvents including ethanol, methanol and cyclopentanol were studied at a constant dye concentration. There were small changes in the PL spectra for the different solvents in terms of PL intensity and peak wavelength. The highest PL intensity was observed for cyclopentanol and the lowest for ethanol. The longest peak wavelength was found in cyclopentanol (716 nm) and the shortest in methanol (708 nm). Dissolving the dye powder in the methanol solvent and varying the dye concentration in aqueous solution from the high concentrated solution to highly dilute states, the wavelength tunability was observed between about 700 nm in the dilute state and 730 nm at high concentration. Such a large shift may be attributed to the formation of dye aggregates. Rho800 dye-doped polyvinyl alcohol (PVA) polymer thin-film was further investigated. The PL intensity of the dye in the form of thin-film is lower than that of the aqueous solution form whereas the peak wavelength is redshifted due to the presence of PVA. This paper, to our best knowledge, reports the first study of spectroscopic properties of Rho800 dyes in various forms and provides useful guidelines for production of controllable organic luminescence sources.

Biomaterial thin film deposition and characterization by means of MAPLE technique

International Nuclear Information System (INIS)

Bloisi, F.; Vicari, L.; Papa, R.; Califano, V.; Pedrazzani, R.; Bontempi, E.; Depero, L.E.

2007-01-01

Polyethylene glycol (PEG) is a polymer with technologically important applications, especially as a biomaterial. Several biomedical applications (such as tissue engineering, spatial patterning of cells, anti-biofouling and biocompatible coatings) require the application of high quality PEG thin films. In order to have a good adhesion to substrate chemically modified polymer molecules have been used, but for some 'in vivo' applications it is essential to deposit a film with the same chemical and structural properties of bulk PEG. Pulsed laser deposition (PLD) technique is generally able to produce high quality thin films but it is inadequate for polymer/organic molecules. MAPLE (Matrix Assisted Pulsed Laser Evaporation) is a recently developed PLD based thin film deposition technique, particularly well suited for organic/polymer thin film deposition. Up to now MAPLE depositions have been carried out mainly by means of modified PLD systems, using excimer lasers operating in UV, but the use of less energetic radiations can minimize the photochemical decomposition of the polymer molecules. We have used a deposition system explicitly designed for MAPLE technique connected to a Q-switched Ng:YAG pulsed laser which can be operated at different wavelength ranging from IR to UV in order to optimise the deposition parameters. The capability of MAPLE technique to deposit PEG has been confirmed and preliminary results show that visible (532 nm wavelength) radiation gives better results with respect to UV (355 nm) radiation. Despite usually UV wavelengths have been used and even if more systematic tests must be performed, it is important to underline that the choice of laser wavelength plays an important role in the application of MAPLE thin film deposition technique

Nanometric thin film membranes manufactured on square meter scale: ultra-thin films for CO 2 capture

KAUST Repository

Yave, Wilfredo; Car, Anja; Wind, Jan; Peinemann, Klaus Viktor

2010-01-01

Miniaturization and manipulation of materials at nanometer scale are key challenges in nanoscience and nanotechnology. In membrane science and technology, the fabrication of ultra-thin polymer films (defect-free) on square meter scale with uniform

Effects of phosphorus on the electrical characteristics of plasma deposited hydrogenated amorphous silicon carbide thin films

Science.gov (United States)

Alcinkaya, Burak; Sel, Kivanc

2018-01-01

The properties of phosphorus doped hydrogenated amorphous silicon carbide (a-SiCx:H) thin films, that were deposited by plasma enhanced chemical vapor deposition technique with four different carbon contents (x), were analyzed and compared with those of the intrinsic a-SiCx:H thin films. The carbon contents of the films were determined by X-ray photoelectron spectroscopy. The thickness and optical energies, such as Tauc, E04 and Urbach energies, of the thin films were determined by UV-Visible transmittance spectroscopy. The electrical properties of the films, such as conductivities and activation energies were analyzed by temperature dependent current-voltage measurements. Finally, the conduction mechanisms of the films were investigated by numerical analysis, in which the standard transport mechanism in the extended states and the nearest neighbor hopping mechanism in the band tail states were taken into consideration. It was determined that, by the effect of phosphorus doping the dominant conduction mechanism was the standard transport mechanism for all carbon contents.

Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

Science.gov (United States)

Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

2016-02-01

Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%.

Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

Science.gov (United States)

Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

On the Mechanism of In Nanoparticle Formation by Exposing ITO Thin Films to Hydrogen Plasmas.

Science.gov (United States)

Fan, Zheng; Maurice, Jean-Luc; Chen, Wanghua; Guilet, Stéphane; Cambril, Edmond; Lafosse, Xavier; Couraud, Laurent; Merghem, Kamel; Yu, Linwei; Bouchoule, Sophie; Roca I Cabarrocas, Pere

2017-10-31

We present our systematic work on the in situ generation of In nanoparticles (NPs) from the reduction of ITO thin films by hydrogen (H 2 ) plasma exposure. In contrast to NP deposition from the vapor phase (i.e., evaporation), the ITO surface can be considered to be a solid reservoir of In atoms thanks to H 2 plasma reduction. On one hand, below the In melting temperature, solid In NP formation is governed by the island-growth mode, which is a self-limiting process because the H 2 plasma/ITO interaction will be gradually eliminated by the growing In NPs that cover the ITO surface. On the other hand, we show that above the melting temperature In droplets prefer to grow along the grain boundaries on the ITO surface and dramatic coalescence occurs when the growing NPs connect with each other. This growth-connection-coalescence behavior is even strengthened on In/ITO bilayers, where In particles larger than 10 μm can be formed, which are made of evaporated In atoms and in situ released ones. Thanks to this understanding, we manage to disperse dense evaporated In NPs under H 2 plasma exposure when inserting an ITO layer between them and substrate like c-Si wafer or glass by modifying the substrate surface chemistry. Further studies are needed for more precise control of this self-assembling method. We expect that our findings are not limited to ITO thin films but could be applicable to various metal NPs generation from the corresponding metal oxide thin films.

Effect of nitrogen environment on NdFeB thin films grown by radio frequency plasma beam assisted pulsed laser deposition

International Nuclear Information System (INIS)

Constantinescu, C.; Patroi, E.; Codescu, M.; Dinescu, M.

2013-01-01

Highlights: ► NdFeB thin films grown by PLD, in vacuum and in nitrogen, are presented. ► Nitrogen inclusion in thin film structures is related to improved coercitivity. ► Magnetical, optical and morphological properties of the thin films are discussed. - Abstract: NdFeB is a very attractive material for applications in electrical engineering and in electronics, for high-tech devices where high coercive field and high remanence are needed. In this paper we demonstrate that the deposition of nitrogen doped NdFeB thin films by pulsed laser deposition, in the presence of a nitrogen radiofrequency plasma beam, exhibit improved magnetic properties and surface morphology, when compared to vacuum deposited NdFeB layers. A Nd:YAG pulsed laser (3ω and 4ω) was focused on a NdFeB target, in vacuum, or in the presence of a nitrogen plasma beam. Substrate temperature (RT-850 °C), nitrogen gas pressure, and radiofrequency power (75–150 W), were particularly varied. The thin films were investigated by means of X-ray diffraction, atomic force microscopy, scanning electron microscopy, spectroscopic-ellipsometry, and vibrating sample magnetometry.

Effect of nitrogen environment on NdFeB thin films grown by radio frequency plasma beam assisted pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Constantinescu, C., E-mail: catalin.constantinescu@inflpr.ro [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor bd., Magurele, RO-077125, Bucharest (Romania); Patroi, E.; Codescu, M. [National Institute for Research and Development in Electrical Engineering - Advanced Research, 313 Spl. Unirii, Sector 3, RO-030138, Bucharest (Romania); Dinescu, M. [National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor bd., Magurele, RO-077125, Bucharest (Romania)

2013-03-01

Highlights: Black-Right-Pointing-Pointer NdFeB thin films grown by PLD, in vacuum and in nitrogen, are presented. Black-Right-Pointing-Pointer Nitrogen inclusion in thin film structures is related to improved coercitivity. Black-Right-Pointing-Pointer Magnetical, optical and morphological properties of the thin films are discussed. - Abstract: NdFeB is a very attractive material for applications in electrical engineering and in electronics, for high-tech devices where high coercive field and high remanence are needed. In this paper we demonstrate that the deposition of nitrogen doped NdFeB thin films by pulsed laser deposition, in the presence of a nitrogen radiofrequency plasma beam, exhibit improved magnetic properties and surface morphology, when compared to vacuum deposited NdFeB layers. A Nd:YAG pulsed laser (3{omega} and 4{omega}) was focused on a NdFeB target, in vacuum, or in the presence of a nitrogen plasma beam. Substrate temperature (RT-850 Degree-Sign C), nitrogen gas pressure, and radiofrequency power (75-150 W), were particularly varied. The thin films were investigated by means of X-ray diffraction, atomic force microscopy, scanning electron microscopy, spectroscopic-ellipsometry, and vibrating sample magnetometry.

How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

KAUST Repository

Wodo, Olga; Ganapathysubramanian, Baskar

2014-01-01

© 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

KAUST Repository

Wodo, Olga

2014-10-13

© 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

High rate deposition of transparent conducting oxide thin films by vacuum arc plasma evaporation

International Nuclear Information System (INIS)

Minami, Tadatsugu; Ida, Satoshi; Miyata, Toshihiro

2002-01-01

Transparent conducting oxide (TCO) thin films have been deposited at a high rate above 370 nm/min by vacuum arc plasma evaporation (VAPE) using sintered oxide fragments as the source material. It was found that the deposition rate of TCO films was strongly dependent on the deposition pressure, whereas the obtained electrical properties were relatively independent of the pressure. Resistivities of 5.6x10 -4 and 2.3x10 -4 Ω·cm and an average transmittance above 80% (with substrate included) in the visible range were obtained in Ga-doped ZnO (GZO) thin films deposited at 100 and 350 deg. C, respectively. In addition, a resistivity as low as 1.4x10 -4 Ω·cm and an average transmittance above 80% were also obtained in indium-tin-oxide (ITO) films deposited at 300 deg. C. The deposited TCO films exhibited uniform distributions of resistivity and thickness on large area substrates

High rate deposition of transparent conducting oxide thin films by vacuum arc plasma evaporation

Energy Technology Data Exchange (ETDEWEB)

Minami, Tadatsugu; Ida, Satoshi; Miyata, Toshihiro

2002-09-02

Transparent conducting oxide (TCO) thin films have been deposited at a high rate above 370 nm/min by vacuum arc plasma evaporation (VAPE) using sintered oxide fragments as the source material. It was found that the deposition rate of TCO films was strongly dependent on the deposition pressure, whereas the obtained electrical properties were relatively independent of the pressure. Resistivities of 5.6x10{sup -4} and 2.3x10{sup -4} {omega}{center_dot}cm and an average transmittance above 80% (with substrate included) in the visible range were obtained in Ga-doped ZnO (GZO) thin films deposited at 100 and 350 deg. C, respectively. In addition, a resistivity as low as 1.4x10{sup -4} {omega}{center_dot}cm and an average transmittance above 80% were also obtained in indium-tin-oxide (ITO) films deposited at 300 deg. C. The deposited TCO films exhibited uniform distributions of resistivity and thickness on large area substrates.

Protein immobilization on epoxy-activated thin polymer films: effect of surface wettability and enzyme loading.

Science.gov (United States)

Chen, Bo; Pernodet, Nadine; Rafailovich, Miriam H; Bakhtina, Asya; Gross, Richard A

2008-12-02

A series of epoxy-activated polymer films composed of poly(glycidyl methacrylate/butyl methacrylate/hydroxyethyl methacrylate) were prepared. Variation in comonomer composition allowed exploration of relationships between surface wettability and Candida antartica lipase B (CALB) binding to surfaces. By changing solvents and polymer concentrations, suitable conditions were developed for preparation by spin-coating of uniform thin films. Film roughness determined by AFM after incubation in PBS buffer for 2 days was less than 1 nm. The occurrence of single CALB molecules and CALB aggregates at surfaces was determined by AFM imaging and measurements of volume. Absolute numbers of protein monomers and multimers at surfaces were used to determine values of CALB specific activity. Increased film wettability, as the water contact angle of films increased from 420 to 550, resulted in a decreased total number of immobilized CALB molecules. With further increases in the water contact angle of films from 55 degrees to 63 degrees, there was an increased tendency of CALB molecules to form aggregates on surfaces. On all flat surfaces, two height populations, differing by more than 30%, were observed from height distribution curves. They are attributed to changes in protein conformation and/or orientation caused by protein-surface and protein-protein interactions. The fraction of molecules in these populations changed as a function of film water contact angle. The enzyme activity of immobilized films was determined by measuring CALB-catalyzed hydrolysis of p-nitrophenyl butyrate. Total enzyme specific activity decreased by decreasing film hydrophobicity.

The role of energetic ions from plasma in the creation of nanostructured materials and stable polymer surface treatments

International Nuclear Information System (INIS)

Bilek, M.M.M.; Newton-McGee, K.; McKenzie, D.R.; McCulloch, D.G.

2006-01-01

Plasma processes for the synthesis of new materials as thin films have enabled the production of a wide variety of new materials. These include meta-stable phases, which are not readily found in nature, and more recently, materials with structure on the nanoscale. Study of plasma synthesis processes at the fundamental level has revealed that ion energy, depositing flux and growth surface temperature are the critical parameters affecting the microstructure and the properties of the thin film materials formed. In this paper, we focus on the role of ion flux and impact energy in the creation of thin films with nanoscale structure in the form of multilayers. We describe three synthesis strategies, based on the extraction of ions from plasma sources and involving modulation of ion flux and ion energy. The microstructure, intrinsic stress and physical properties of the multilayered samples synthesized are studied and related back to the conditions at the growth surface during deposition. When energetic ions of a non-condensing species are used, it is possible to place active groups on the surfaces of materials such as polymers. These active groups can then be used as bonding sites in subsequent chemical attachment of proteins or other macromolecules. If the energy of the non-condensing ions is increased to a few keV then modified layers buried under the surface can be produced. Here we describe a method by which the aging effect, which is often observed in plasma surface modifications on polymers, can be reduced and even eliminated using high energy ion bombardment

Characterisation and vapour sensing properties of spin coated thin films of anthracene labelled PMMA polymer

Energy Technology Data Exchange (ETDEWEB)

Capan, I., E-mail: inci.capan@gmail.com [Balikesir University, Faculty of Art and Sciences, Department of Physics, Cagis Campus, 10145 Balikesir (Turkey); Tarimci, C., E-mail: Celik.Tarimci@eng.ankara.edu.tr [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Ankara (Turkey); Erdogan, M., E-mail: merdogan@balikesir.edu.tr [Balikesir University, Faculty of Art and Sciences, Department of Physics, Cagis Campus, 10145 Balikesir (Turkey); Hassan, A.K., E-mail: A.Hassan@shu.ac.uk [Materials and Engineering Research Institute, Sheffield Hallam University, Sheaf Building, Pond Street, Sheffield S1 1WB (United Kingdom)

2009-05-05

In the present article thin films of poly (methyl methacrylate) (PMMA) polymer labelled with anthracene (Ant-PMMA) prepared by spin coating are characterised by UV-visible spectroscopy, surface plasmon resonance (SPR), spectroscopic ellipsometry (SE) and Atomic Force Microscopy (AFM) and their organic vapour sensing properties are investigated. Ant-PMMA films' thickness are determined by performing theoretical fitting to experimental data measured using SPR and SE. Results obtained show that the spin-cast films are of good uniformity with an average thickness of 6-8 nm. Organic vapour sensing properties are studied using SPR technique during exposures to different volatile organic compounds (VOCs). Ant-PMMA films' response to the selected VOCs has been examined in terms of solubility parameters and molar volumes of the solvents, and the films were found to be largely sensitive to benzene vapour compared to other studied analytes.

Characterisation and vapour sensing properties of spin coated thin films of anthracene labelled PMMA polymer

International Nuclear Information System (INIS)

Capan, I.; Tarimci, C.; Erdogan, M.; Hassan, A.K.

2009-01-01

In the present article thin films of poly (methyl methacrylate) (PMMA) polymer labelled with anthracene (Ant-PMMA) prepared by spin coating are characterised by UV-visible spectroscopy, surface plasmon resonance (SPR), spectroscopic ellipsometry (SE) and Atomic Force Microscopy (AFM) and their organic vapour sensing properties are investigated. Ant-PMMA films' thickness are determined by performing theoretical fitting to experimental data measured using SPR and SE. Results obtained show that the spin-cast films are of good uniformity with an average thickness of 6-8 nm. Organic vapour sensing properties are studied using SPR technique during exposures to different volatile organic compounds (VOCs). Ant-PMMA films' response to the selected VOCs has been examined in terms of solubility parameters and molar volumes of the solvents, and the films were found to be largely sensitive to benzene vapour compared to other studied analytes.

Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

International Nuclear Information System (INIS)

Biederman, H.; Holland, L.

1983-01-01

Fluorocarbon films have been prepared by plasma polymerization of CF 4 using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an r.f. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF 4 [25%]-argon[75%] mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF 4 [87%]-argon[13%] were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF 4 as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an EAS study. The sheet resistivity of the metal/polymer film complexes was determined. (orig.)

Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

Energy Technology Data Exchange (ETDEWEB)

Biederman, H.; Holland, L. (Sussex Univ., Brighton (UK). Lab. for Plasma Materials Processing)

1983-07-01

Fluorocarbon films have been prepared by plasma polymerization of CF/sub 4/ using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an R.F. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF/sub 4/(25%)-argon(75%) mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF/sub 4/(87%)-argon(13%) were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF/sub 4/ as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an EAS study. The sheet resistivity of the metal/polymer film complexes was determined.

Heat treatment and aging effect on the structural and optical properties of plasma polymerized 2,6-diethylaniline thin films

International Nuclear Information System (INIS)

Matin, Rummana; Bhuiyan, A.H.

2012-01-01

The monomer, 2,6-diethylaniline has been used to deposit plasma polymerized 2,6-diethylaniline (PPDEA) thin films at room temperature on to glass substrates by a capacitively coupled parallel plate glow discharge reactor. A comparative analysis on the changes of morphological, structural and optical properties of as-deposited, heat treated and aged PPDEA thin films is ascertained. Scanning electron microscopy shows uniform and pinhole free surface of PPDEA thin films and no significant difference in the surface morphology is observed due to heat treatment. Electron dispersive X-ray and Fourier transform infrared spectroscopic investigations indicate some structural rearrangement in PPDEA thin films due to heat treatment. Differential thermal analysis, thermogravimetric analysis and differential thermogravimetric analysis suggest that the PPDEA is thermally stable up to about 580 K. The study on the optical absorption spectra of as-deposited, heat treated and aged PPDEA thin films of different thicknesses lead to the determination of the allowed direct and indirect transition energies ranging from 3.63 to 2.73 and 2.38 to 1.26 eV respectively. Urbach energy, steepness parameter and extinction coefficient are also assessed. It is observed that the optical parameters of as-deposited PPDEA thin films change due to heat treatment and do not change appreciably due to aging. - Highlights: ► Heat treatment and aging effect of plasma polymerized 2,6-diethylaniline thin films. ► The surface morphology of PPDEA is found uniform for all types of sample. ► Heat treatment introduces some elemental and structural rearrangement. ► The thermal stability is found up to about 580 K. ► Optical parameters were changed for heat treatment but not markedly for aging.

Etching characteristic and mechanism of BST thin films using inductively coupled Cl2/Ar plasma with additive CF4 gas

International Nuclear Information System (INIS)

Kim, Gwan-Ha; Kim, Kyoung-Tae; Kim, Dong-Pyo; Kim, Chang-Il

2004-01-01

BST thin films were etched with inductively coupled CF 4 /(Cl 2 +Ar) plasmas. The maximum etch rate of the BST thin films was 53.6 nm/min for a 10% CF 4 to the Cl 2 /Ar gas mixture at RF power of 700 W, DC bias of -150 V, and chamber pressure of 2 Pa. Small addition of CF 4 to the Cl 2 /Ar mixture increased chemical effect. Consequently, the increased chemical effect caused the increase in the etch rate of the BST thin films. To clarify the etching mechanism, the surface reaction of the BST thin films was investigated by X-ray photoelectron spectroscopy

Polymer-ZnO nanocomposites foils and thin films for UV protection

International Nuclear Information System (INIS)

Shanshool, Haider Mohammed; Yahaya, Muhammad; Abdullah, Ibtisam Yahya; Yunus, Wan Mahmood Mat

2014-01-01

The damage of UV radiation on human eye and skin is extensively studied. In the present work, the nanocomposites foils and thin films have been prepared by using casting method and spin coating, respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with Polymethyl methacrylate (PMMA) and Polyvinylidene fluoride (PVDF) as polymer matrix. Different contents of ZnO nanoparticles were used as filler in the nanocomposites. UV-Vis spectra showed very low transmittance in UV region that decreases with increase content of ZnO. PVDF/ZnO samples showed the lowest transmittance. The rough surface of PVDF was observed from SEM image. While a homogeneous dispersion of ZnO nanoparticles in PMMA were indicated by FESEM images

Polymer-ZnO nanocomposites foils and thin films for UV protection

Energy Technology Data Exchange (ETDEWEB)

Shanshool, Haider Mohammed; Yahaya, Muhammad; Abdullah, Ibtisam Yahya [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, University Putra Malaysia, 43400 UPM, Serdang (Malaysia)

2014-09-03

The damage of UV radiation on human eye and skin is extensively studied. In the present work, the nanocomposites foils and thin films have been prepared by using casting method and spin coating, respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with Polymethyl methacrylate (PMMA) and Polyvinylidene fluoride (PVDF) as polymer matrix. Different contents of ZnO nanoparticles were used as filler in the nanocomposites. UV-Vis spectra showed very low transmittance in UV region that decreases with increase content of ZnO. PVDF/ZnO samples showed the lowest transmittance. The rough surface of PVDF was observed from SEM image. While a homogeneous dispersion of ZnO nanoparticles in PMMA were indicated by FESEM images.

[Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

Science.gov (United States)

1998-01-01

The work performed during the current renewal period, March 1,1998 focused primarily on the synthesis and characterization of a sugar based electrolyte for thin-film polymer batteries. The initial phase of the project involved developing a suitable sugar to use as the monomer in the polymeric electrolyte synthesis. The monomer has been synthesized and characterized completely. Overall the yield of this material is high and it can be produced in relatively large quantity easily and in high purity. The scheme used for the preparation of the monomer is outlined along with pertinent yields.

Preparation of anatase TiO{sub 2} thin film by low temperature annealing as an electron transport layer in inverted polymer solar cells

Energy Technology Data Exchange (ETDEWEB)

Noh, Hongche [Department of Chemical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Oh, Seong-Geun, E-mail: seongoh@hanyang.ac.kr [Department of Chemical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Im, Seung Soon, E-mail: imss007@hanyang.ac.kr [Department of Organic and Nano Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

2015-04-01

Highlights: • Anatase thin film of TiO{sub 2} was prepared by low temperature annealing. • Anatase TiO{sub 2} colloidal solution was obtained from amorphous form through solvothermal process. • Anatase TiO{sub 2} colloidal solution was used to prepare thin film on ITO glass. • Polymer solar cell fabricated on anatase TiO{sub 2} thin film showed 2.6% of PCE. - Abstract: To prepare the anatase TiO{sub 2} thin films on ITO glass, amorphous TiO{sub 2} colloidal solution was synthesized through the simple sol-gel method by using titanium (IV) isopropoxide as a precursor. This amorphous TiO{sub 2} colloidal solution was spread on ITO glass by spin-coating, then treated at 450 °C to obtain anatase TiO{sub 2} film (for device A). For other TiO{sub 2} films, amorphous TiO{sub 2} colloidal solution was treated through solvothermal process at 180 °C to obtain anatase TiO{sub 2} colloidal solution. This anatase TiO{sub 2} colloidal solution was spread on ITO glass by spin coating, and then annealed at 200 °C (for device B) and 130 °C (for device C), respectively. The average particle size of amorphous TiO{sub 2} colloidal solution was about 1.0 nm and that of anatase TiO{sub 2} colloidal solution was 10 nm. The thickness of TiO{sub 2} films was about 15 nm for all cases. When inverted polymer solar cells were fabricated by using these TiO{sub 2} films as an electron transport layer, the device C showed the highest PCE (2.6%) due to the lack of defect, uniformness and high light absorbance of TiO{sub 2} films. The result of this study can be applied for the preparation of inverted polymer solar cell using TiO{sub 2} films as a buffer layer at low temperature on plastic substrate by roll-to roll process.

Removable polytetrafluoroethylene template based epitaxy of ferroelectric copolymer thin films

Science.gov (United States)

Xia, Wei; Chen, Qiusong; Zhang, Jian; Wang, Hui; Cheng, Qian; Jiang, Yulong; Zhu, Guodong

2018-04-01

In recent years ferroelectric polymers have shown their great potentials in organic and flexible electronics. To meet the requirements of high-performance and low energy consumption of novel electronic devices and systems, structural and electrical properties of ferroelectric polymer thin films are expected to be further optimized. One possible way is to realize epitaxial growth of ferroelectric thin films via removable high-ordered polytetrafluoroethylene (PTFE) templates. Here two key parameters in epitaxy process, annealing temperature and applied pressure, are systematically studied and thus optimized through structural and electrical measurements of ferroelectric copolymer thin films. Experimental results indicate that controlled epitaxial growth is realized via suitable combination of both parameters. Annealing temperature above the melting point of ferroelectric copolymer films is required, and simultaneously moderate pressure (around 2.0 MPa here) should be applied. Over-low pressure (around 1.0 MPa here) usually results in the failure of epitaxy process, while over-high pressure (around 3.0 MPa here) often results in residual of PTFE templates on ferroelectric thin films.

Molecular Weight Effects on the Glass Transition and Confinement Behavior of Polymer Thin Films.

Science.gov (United States)

Xia, Wenjie; Hsu, David D; Keten, Sinan

2015-08-01

Nanoscale polymer thin films exhibit strong confinement effects on Tg arising from free surfaces. However, the coupled influence of molecular weight (MW) and surface effects on Tg is not well understood for low MW film systems below the entanglement length. Utilizing atomistically informed coarse-grained molecular dynamics simulations for poly(methyl methacrylate) (PMMA), it is demonstrated that the decrease in free-standing film Tg with respect to bulk is more significant for low MW compared to high MW systems. Investigation of the local interfacial properties reveals that the increase in the local free volume near the free surface is greater for low MW, explaining the MW dependence of Tg -confinement behaviors. These findings corroborate recent experiments on low MW films, and highlight the relationship between nanoconfinement phenomena and local free volume effects arising from free surfaces. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrophobicity studies of polymer thin films with varied CNT concentration

Science.gov (United States)

M. Rodzi, N. H.; M. Shahimin, M.; Poopalan, P.; Man, B.; M. Nor, M. N.

2013-12-01

Surface functionalization studies for re-creating a `Lotus Leaf' effect (superhydrophobic) have been carried out for the past decade; looking for the material which can provide high transparency, low energy surface and high surface roughness. Fabrication of polydimethylsiloxane (PDMS) and multiwalled carbon nanotubes (MWCNT) hybrid thin film variations on glass to produce near-superhydrophobic surfaces is presented in this paper. There are three important parameters studied in producing hydrophobic surfaces based on the hybrid thin films; concentration of PDMS, concentration of MWCNT and droplet sizes. The study is carried out by using PDMS of varied cross linker ratio (10:1, 30:1 and 50:1) with MWCNT concentration of 1mg, 10mg and 15mg for 0.5 μl, 2.0 μl, 5.0 μl and 10 μl droplet sizes. The resulting hybrid thin films show that hydrophobicity increased with increasing cross linker ratio and MWCNT percentage in the PDMS solution. A near superhydrophobic surface can be created when using 15 mg of MWCNT with 50:1 cross linker ratio PDMS thin films, measured on 10 μl droplet size. The hybrid thin films produced can be potentially tailored to the application of biosensors, MEMS and even commercial devices.

Junction Propagation in Organometal Halide Perovskite-Polymer Composite Thin Films.

Science.gov (United States)

Shan, Xin; Li, Junqiang; Chen, Mingming; Geske, Thomas; Bade, Sri Ganesh R; Yu, Zhibin

2017-06-01

With the emergence of organometal halide perovskite semiconductors, it has been discovered that a p-i-n junction can be formed in situ due to the migration of ionic species in the perovskite when a bias is applied. In this work, we investigated the junction formation dynamics in methylammonium lead tribromide (MAPbBr 3 )/polymer composite thin films. It was concluded that the p- and n- doped regions propagated into the intrinsic region with an increasing bias, leading to a reduced intrinsic perovskite layer thickness and the formation of an effective light-emitting junction regardless of perovskite layer thicknesses (300 nm to 30 μm). The junction propagation also played a major role in deteriorating the LED operation lifetime. Stable perovskite LEDs can be achieved by restricting the junction propagation after its formation.

Layer-by-layer assembly of thin film oxygen barrier

International Nuclear Information System (INIS)

Jang, Woo-Sik; Rawson, Ian; Grunlan, Jaime C.

2008-01-01

Thin films of sodium montmorillonite clay and cationic polyacrylamide were grown on a polyethylene terephthalate film using layer-by-layer assembly. After 30 clay-polymer layers are deposited, with a thickness of 571 nm, the resulting transparent film has an oxygen transmission rate (OTR) below the detection limit of commercial instrumentation ( 2 /day/atm). This low OTR, which is unprecedented for a clay-filled polymer composite, is believed to be due to a brick wall nanostructure comprised of completely exfoliated clay in polymeric mortar. With an optical transparency greater than 90% and potential for microwaveability, this thin composite is a good candidate for foil replacement in food packaging and may also be useful for flexible electronics packaging

Expandable and retractable self-rolled structures based on metal/polymer thin film for flow sensing

Science.gov (United States)

Zhu, Jianzhong; White, Carl; Saadat, Mehdi; Bart-Smith, Hilary

2015-11-01

Most aquatic animals such as fish rely heavily on their ability of detect and respond to ambient flows in order to explore and inhabit various habitats or survive predator-prey encounters. Fish utilize neuromasts in their skin surface and lateral lines in their bodies to align themselves while swimming upstream for migration, avoid obstacles, reduce locomotion cost, and detect flow variations caused by potential predators. In this study, a thin film MEMS sensor analogous to a fish neuromast has been designed for flow sensing. Residual stress arises in many thin film materials during processing. Metal and polymer thin film materials with a significant difference in elastic modular were chosen to form a multiple-layer structure. Upon releasing, the structure rolls into a tube due to mechanical property mismatch. The self-rolled tube can expand or retract, depending on the existence of external force such as flow. An embedded strain sensor detects the deformation of the tube and hence senses the ambient flow. Numerical simulations were conducted to optimize the structural design. Experiments were performed in a flow tank to quantify the performance of the sensor. This research is supported by the Office of Naval Research under the MURI Grant N00014-14-1-0533.

Rapid synthesis of flexible conductive polymer nanocomposite films

International Nuclear Information System (INIS)

Blattmann, C O; Sotiriou, G A; Pratsinis, S E

2015-01-01

Polymer nanocomposite films with nanoparticle-specific properties are sought out in novel functional materials and miniaturized devices for electronic and biomedical applications. Sensors, capacitors, actuators, displays, circuit boards, solar cells, electromagnetic shields and medical electrodes rely on flexible, electrically conductive layers or films. Scalable synthesis of such nanocomposite films, however, remains a challenge. Here, flame aerosol deposition of metallic nanosliver onto bare or polymer-coated glass substrates followed by polymer spin-coating on them leads to rapid synthesis of flexible, free-standing, electrically conductive nanocomposite films. Their electrical conductivity is determined during their preparation and depends on substrate composition and nanosilver deposition duration. Accordingly, thin (<500 nm) and flexible nanocomposite films are made having conductivity equivalent to metals (e.g. 5  × 10 4 S cm −1 ), even during repetitive bending. (paper)

Applications of thin-film sandwich crystallization platforms

Energy Technology Data Exchange (ETDEWEB)

Axford, Danny, E-mail: danny.axford@diamond.ac.uk; Aller, Pierre; Sanchez-Weatherby, Juan; Sandy, James [Diamond Light Source, Harwell Oxford, Didcot OX11 0DE (United Kingdom)

2016-03-24

Crystallization via sandwiches of thin polymer films is presented and discussed. Examples are shown of protein crystallization in, and data collection from, solutions sandwiched between thin polymer films using vapour-diffusion and batch methods. The crystallization platform is optimal for both visualization and in situ data collection, with the need for traditional harvesting being eliminated. In wells constructed from the thinnest plastic and with a minimum of aqueous liquid, flash-cooling to 100 K is possible without significant ice formation and without any degradation in crystal quality. The approach is simple; it utilizes low-cost consumables but yields high-quality data with minimal sample intervention and, with the very low levels of background X-ray scatter that are observed, is optimal for microcrystals.

Plasma-polymerized SiOx deposition on polymer film surfaces for preparation of oxygen gas barrier polymeric films

International Nuclear Information System (INIS)

Inagaki, N.

2003-01-01

SiOx films were deposited on surfaces of three polymeric films, PET, PP, and Nylon; and their oxygen gas barrier properties were evaluated. To mitigate discrepancies between the deposited SiOx and polymer film, surface modification of polymer films was done, and how the surface modification could contribute to was discussed from the viewpoint of apparent activation energy for the permeation process. The SiOx deposition on the polymer film surfaces led to a large decrease in the oxygen permeation rate. Modification of polymer film surfaces by mans of the TMOS or Si-COOH coupling treatment in prior to the SiOx deposition was effective in decreasing the oxygen permeation rate. The cavity model is proposed as an oxygen permeation process through the SiOx-deposited Nylon film. From the proposed model, controlling the interface between the deposited SiOx film and the polymer film is emphasized to be a key factor to prepare SiOx-deposited polymer films with good oxygen gas barrier properties. (author)

Polymer and organic solar cells viewed as thin film technologies: What it will take for them to become a success outside academia

DEFF Research Database (Denmark)

Krebs, Frederik C; Jørgensen, Mikkel

2013-01-01

The polymer and organic solar cell technology is critically presented in the context of other thin film technologies with a specific focus on what it will take to make them a commercial success. The academic success of polymer and organic solar cells far outweigh any other solar cell technology w...

Fabrication of high-performance InGaZnOx thin film transistors based on control of oxidation using a low-temperature plasma

Science.gov (United States)

Takenaka, Kosuke; Endo, Masashi; Uchida, Giichiro; Setsuhara, Yuichi

2018-04-01

This work demonstrated the low-temperature control of the oxidation of Amorphous InGaZnOx (a-IGZO) films using inductively coupled plasma as a means of precisely tuning the properties of thin film transistors (TFTs) and as an alternative to post-deposition annealing at high temperatures. The effects of the plasma treatment of the as-deposited a-IGZO films were investigated by assessing the electrical properties of TFTs incorporating these films. A TFT fabricated using an a-IGZO film exposed to an Ar-H2-O2 plasma at substrate temperatures as low as 300 °C exhibited the best performance, with a field effect mobility as high as 42.2 cm2 V-1 s-1, a subthreshold gate voltage swing of 1.2 V decade-1, and a threshold voltage of 2.8 V. The improved transfer characteristics of TFTs fabricated with a-IGZO thin films treated using an Ar-H2-O2 plasma are attributed to the termination of oxygen vacancies around Ga and Zn atoms by OH radicals in the gas phase.

Cell behaviors on micro-patterned porous thin films

International Nuclear Information System (INIS)

Phong, Ho Quoc; Wang Shuling; Wang, Meng-Jiy

2010-01-01

Thin polymer films with patterned surfaces have drawn tremendous attention in manufacturing advanced electronic, mechanical devices and in biomaterials due to the advantageous properties such as mechanical strength, chemical resistance and optic transparency. The applications can be extended to the fields such as catalysts, antireflection coatings, template for inorganic growth masks, and substrates for cell culturing providing the patterned surface containing micron-sized features. Various methods have been used to fabricate polymers with micro-patterned surfaces such as photolithographic, ink-jet printing, nonsolvent, spin coating in a dry environment, self-organization, and the condensation of monodisperse water droplet on the polymer solution. The physiological functions of mature cells depend on the microenvironment/niche surrounding which can provide proper factors to regulate cell proliferation and differentiation. While designing appropriate scaffolds for tissue engineering, the microstructure is one of the most important factors to be considered. In this work, a facile single-step phase separation method was used to create micro-patterned polymer thin films with concaves or convexes with sizes ranged from 7 to 70 μm. The effects of water content, casting volume and the addition of surfactant on the distribution of pores and substrate morphology were examined. Moreover, detailed observations of fibroblast cells on the micro-patterned thin films were presented to compare and elucidate the roles of surface micro-features and chemical functionalities.

Effect of oxygen plasma treatment on crystal growth mode at pentacene/Ni interface in organic thin-film transistors.

Science.gov (United States)

Song, Bang Joo; Hong, Kihyon; Kim, Woong-Kwon; Kim, Kisoo; Kim, Sungjun; Lee, Jong-Lam

2010-11-25

We report how treatment of nickel (Ni) with O(2) plasma affects the polarity of Ni surface, crystallinity of pentacene film on the Ni, and electrical properties of pentacene organic thin-film transistors (OTFTs) that use Ni as source-drain electrodes. The polar component of surface energy in Ni surface increased from 8.1 to 43.3 mJ/m(2) after O(2)-plasma treatment for 10 s. From X-ray photoelectron spectra and secondary electron emission spectra, we found that NiO(x) was formed on the O(2)-plasma-treated Ni surface and the work function of O(2)-plasma-treated Ni was 0.85 eV higher than that of untreated Ni. X-ray diffraction and atomic force microscopy measurements showed that pentacene molecules are well aligned as a thin-film and grains grow much larger on O(2)-plasma-treated Ni than on untreated Ni. This change in the growth mode is attributed to the reduction of interaction energy between pentacene and Ni due to formation of oxide at the Ni/pentacene interface. Thus, O(2)-plasma treatment promoted the growth of well-ordered pentacene film and lowered both the hole injection barrier and the contact resistance between Ni and pentacene by forming NiO(x), enhancing the electrical property of bottom-contact OTFTs.

Synthesis and organisation of poly-substituted porphyrins in thin films for the elaboration of a highly conjugated 2D polymer

International Nuclear Information System (INIS)

Da Cruz, Fernande

1997-01-01

This research thesis addresses the production and characterization of organic thin layers for the elaboration of a wholly conjugated bi-dimensional polymer. The author first reports the synthesis of molecules belonging to the substituted porphyrin family substituted by reactive functions (acetylenic and thiophene functions). He reports how these molecules are organised under the form of a plane paving by using the Langmuir-Blodgett (LB) technique and self-assembly. It has been possible to obtain steady and organised LB films from one the synthesized porphyrins. A new method of organisation based on self-assembly has been developed, and allowed polymerizable organised porphyrin single layers to be obtained. This opens a promising way to the production of the bi-dimensional polymer. Thin films have been characterized by UV-visible spectrophotometry, IR spectrometry, X-ray diffraction, and linear dichroism [fr

Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

Science.gov (United States)

Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

1974-01-01

Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

Application of plasma technology for the modification of polymer and textile materials

Directory of Open Access Journals (Sweden)

Radetić Maja M.

2004-01-01

Full Text Available Plasma treatment is based on the physico-chemical changes of the material surface and as an ecologically and economically acceptable process it can be an attractive alternative to conventional modifications. The possibilities of plasma technology application to the modification of polymer and textile materials are discussed. Different specific properties of the material can be achieved by plasma cleaning, etching, functionalization or polymerization. The final effects are strongly influenced by the treatment parameters (treatment time, pressure, power, gas flow, the applied gas and nature of the material. The plasma treatment of polymers is predominantly focused on cleaning and activation of the surfaces to increase adhesion, binding, wettability, dye ability and printability. Current studies deal more with plasma polymerization where an ultra thin film of plasma polymer is deposited on the material surface and, depending on the applied monomer, different specific properties can be obtained (i.e. chemical and thermal resistance, abrasion resistance, antireflexion, water repellence, etc.. Plasma application to textiles is mostly oriented toward wool and synthetic fibres, though some studies also consider cotton, hemp, flax and silk. The main goal of plasma treatment is to impart a more hydrophilic fibre surface and accordingly increase wettability, dye ability, printability and particularly, shrink resistance in the case of wool. Recent studies have favored technical textiles, where plasma polymerization can offer a wide range of opportunities.

Mechanism of Crystallization and Implications for Charge Transport in Poly(3-ethylhexylthiophene) Thin Films

KAUST Repository

Duong, Duc T.

2014-04-09

In this work, crystallization kinetics and aggregate growth of poly(3-ethylhexylthiophene) (P3EHT) thin films are studied as a function of film thickness. X-ray diffraction and optical absorption show that individual aggregates and crystallites grow anisotropically and mostly along only two packing directions: the alkyl stacking and the polymer chain backbone direction. Further, it is also determined that crystallization kinetics is limited by the reorganization of polymer chains and depends strongly on the film thickness and average molecular weight. Time-dependent, field-effect hole mobilities in thin films reveal a percolation threshold for both low and high molecular weight P3EHT. Structural analysis reveals that charge percolation requires bridged aggregates separated by a distance of ≈2-3 nm, which is on the order of the polymer persistence length. These results thus highlight the importance of tie molecules and inter-aggregate distance in supporting charge percolation in semiconducting polymer thin films. The study as a whole also demonstrates that P3EHT is an ideal model system for polythiophenes and should prove to be useful for future investigations into crystallization kinetics. Recrystallization kinetics and its relationship to charge transport in poly(3-ethylhexylthiophene) (P3EHT) thin films are investigated using a combination of grazing incidence X-ray diffraction, optical absorption, and field-effect transistor measurements. These results show that thin film crystallization kinetics is limited by polymer chain reorganization and that charge percolation depends strongly on the edge-to-edge distance between aggregates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Properties of thin films deposited from HMDSO/O2 induced remote plasma: Effect of oxygen fraction

International Nuclear Information System (INIS)

Saloum, S.; Naddaf, M.; Al-Khaled, B.

2008-01-01

Thin films deposited from hexamethyle disiloxane (HMDSO)/O 2 mixture excited in a radio-frequency hollow cathode discharge system have been investigated for their structural, optical and corrosive properties as a function of oxygen fraction χo 2 (χo 2 =0, 0.38, 0.61, 0.76 and 0.90). It is found that the effect of oxygen fraction on films properties is related to O 2 dissociation degree (αd) behavior in pure oxygen plasma. αd has been investigated by actinometry optical emission spectroscopy (AOES) combined with double langmuir probe measurements, a maximum of O 2 dissociation degree of 15% has been obtained for 50 sccm flow rate of O 2 (χo 2 =0.61 in HMDSO/O 2 plasma). Fourier transform infrared spectroscopy (FTIR) and optical measurements showed that the behavior of both identified IR group densities and deposition rate as a function of oxygen fraction is similar to that of O 2 dissociation degree. The inorganic nature of the films depends significantly on oxygen fraction, the best inorganic structure of deposited films has been obtained for 62% HMDSO content in the mixture HMDSO/O 2 (χo 2 =0.38). The refractive index for deposited films from pure HMDSO(χo 2 =0) has been found to be higher than that of films deposited from HMDSO/O 2 mixture. In HMDSO/O 2 plasma, it has a behavior similar to that of deposition rate, and it is comparable to that of quartz. The effect of oxygen fraction on the corrosive properties of thin films deposited on steel has been investigated. It is found that the measured corrosion current density in 0.1 M KCI solution decreases with the addition of O 2 to HMDSO plasma, and it is minimum for χo 2 =0.38. (author)

PVD processes of thin films deposition using Hall-current discharge

International Nuclear Information System (INIS)

Svadkovskij, I.V.

2007-01-01

Results of research and developments in the field of PVD processes of thin films deposition using Hall-current discharge have been summarized. Effects of interaction of ions with surface during deposition have been considered. Also features of application and prospects of devices based on ion beam and magnetron sputtering systems in thin films technologies have been analyzed. The aspects in the field plasma physics, technology and equipment plasma PVD processes of thin films deposition have been systematized, on the base of investigations made by author and other scientists. (authors)

Thermomechanical properties of polymer nanocomposites: Exploring a unified relationship with planar polymer films

Science.gov (United States)

Bansal, Amitabh

The thermal and mechanical response of polymers, which provide limitations to their practical use, are greatly improved by the addition of a small fraction of an inorganic nanofiller. However, the resulting changes in polymer properties are poorly understood, primarily due to the non-uniform spatial distribution of nanoparticles. This research explores the properties of polystyrene filed with silica nanoparticles and illustrates for the first time that the thermodynamic properties of "polymer nanocomposites" are quantitatively equivalent to the well-understood case of planar polymer films with a uniform thickness. These ideas are quantified by drawing a direct analogy between thin film thickness and an appropriate average ligament thickness measured using electron microscopy. The change in polymer glass transition temperatures with decreasing ligament thickness were found to be quantitatively equivalent to the corresponding thin film data. In combination with viscoelastic properties of the nanocomposites that are in quantitative agreement with data from thin films, these conclusions provide a facile means of understanding and predicting the thermomechanical properties and, potentially, the engineering properties of practically relevant polymer nanocomposites. Grafting of high molecular weight polystyrene onto the silica nanoparticles greatly improves the dispersion quality of nanofillers and also provides a means to tailor the thermo-mechanical properties in nanocomposites. It is concluded that the grafted polystyrene is akin to polymer brushes on flat surfaces. The mobility and stiffness of these grafted chains are expected to be low as compared to the free polymer. In this context a mechanism for the increase in glass transition is proposed: (1) the stiff grafted chains will tend to decrease mobility and thus increase glass transition, (2) the extent of interdigitation of the grafted polystyrene into the matrix will determine the extent to which the nanocomposite

Oriented thin films of mixture of a low-bandgap polymer and a fullerene derivative prepared by friction-transfer method

Science.gov (United States)

Tanigaki, Nobutaka; Mizokuro, Toshiko; Miyadera, Tetsuhiko; Shibata, Yousei; Koganezawa, Tomoyuki

2018-02-01

We have been studying oriented thin films of polymers fabricated by the friction-transfer method, which allows the alignment of a variety of conjugated polymers into highly oriented films. In this study, we prepared oriented blend films of a mixture of a low-bandgap polymer, poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl} (PTB7), and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), which is a promising combination for application in organic solar cells. We obtained oriented blend films of PTB7 and PC71BM by the friction-transfer method from a solid block. Polarized UV-visible spectra show that the PTB7 chains were aligned parallel to the friction direction in the blend films. Grazing-incidence X-ray diffraction (GIXD) studies with synchrotron radiation suggested that the preferred orientation of PTB7 crystallites was face-on in the blend films. The GIXD results also showed the high uniaxial orientation of PTB7 chains in blend films. Photovoltaic devices were fabricated using the friction-transferred blend films of the PTB7 and PC71BM. These bulk heterojunction devices showed better performance than planar heterojunction devices fabricated using pure friction-transferred PTB7 films.

Thermal expansion coefficient and thermomechanical properties of SiN(x) thin films prepared by plasma-enhanced chemical vapor deposition.

Science.gov (United States)

Tien, Chuen-Lin; Lin, Tsai-Wei

2012-10-20

We present a new method based on fast Fourier transform (FFT) for evaluating the thermal expansion coefficient and thermomechanical properties of thin films. The silicon nitride thin films deposited on Corning glass and Si wafers were prepared by plasma-enhanced chemical vapor deposition in this study. The anisotropic residual stress and thermomechanical properties of silicon nitride thin films were studied. Residual stresses in thin films were measured by a modified Michelson interferometer associated with the FFT method under different heating temperatures. We found that the average residual-stress value increases when the temperature increases from room temperature to 100°C. Increased substrate temperature causes the residual stress in SiN(x) film deposited on Si wafers to be more compressive, but the residual stress in SiN(x) film on Corning glass becomes more tensile. The residual-stress versus substrate-temperature relation is a linear correlation after heating. A double substrate technique is used to determine the thermal expansion coefficients of the thin films. The experimental results show that the thermal expansion coefficient of the silicon nitride thin films is 3.27×10(-6)°C(-1). The biaxial modulus is 1125 GPa for SiN(x) film.

Surface analysis of the selective excimer laser patterning of a thin PEDOT:PSS film on flexible polymer films

Science.gov (United States)

Schaubroeck, David; De Smet, Jelle; Willems, Wouter; Cools, Pieter; De Geyter, Nathalie; Morent, Rino; De Smet, Herbert; Van Steenbeerge, Geert

2016-07-01

Fast patterning of highly conductive polymers like PEDOT:PSS (poly (3,4-ethylene dioxythiophene): polystyrene sulfonate) with lasers can contribute to the development of industrial production of liquid crystal displays on polymer foils. In this article, the selective UV laser patterning of a PEDOT:PSS film on flexible polymer films is investigated. Based on their optical properties, three polymer films are investigated: polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and cellulose triacetate (TAC). Ablation parameters for a 110 nm PEDOT:PSS film on these polymer films are optimized. A detailed study of the crater depth, topography and surface composition are provided using optical profilometry, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The electrical insulation of the lines is measured and correlated to the crater analyses for different laser settings. Finally, potential ablation parameters for each of the polymer films are derived.

Reverse-osmosis membranes by plasma polymerization

Science.gov (United States)

Hollahan, J. R.; Wydeven, T.

1972-01-01

Thin allyl amine polymer films were developed using plasma polymerization. Resulting dry composite membranes effectively reject sodium chloride during reverse osmosis. Films are 98% sodium chloride rejective, and 46% urea rejective.

Characteristics of ITO films with oxygen plasma treatment for thin film solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Park, Yong Seob [Department of Photoelectronics Information, Chosun College of Science and Technology, Gwangju (Korea, Republic of); Kim, Eungkwon [Digital Broadcasting Examination, Korean Intellectual Property Office, Daejeon, Suwon 440-746 (Korea, Republic of); Hong, Byungyou [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong, 300, Jangan-gu, Suwon 440-746 (Korea, Republic of); Lee, Jaehyoeng, E-mail: jaehyeong@skku.edu [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong, 300, Jangan-gu, Suwon 440-746 (Korea, Republic of)

2013-12-15

Graphical abstract: The effect of O{sub 2} plasma treatment on the surface and the work function of ITO films. - Highlights: • ITO films were prepared on the glass substrate by RF magnetron sputtering method. • Effects of O{sub 2} plasma treatment on the properties of ITO films were investigated. • The work function of ITO film was changed from 4.67 to 5.66 eV by plasma treatment. - Abstract: The influence of oxygen plasma treatment on the electro-optical and structural properties of indium-tin-oxide films deposited by radio frequency magnetron sputtering method were investigated. The films were exposed at different O{sub 2} plasma powers and for various durations by using the plasma enhanced chemical vapor deposition (PECVD) system. The resistivity of the ITO films was almost constant, regardless of the plasma treatment conditions. Although the optical transmittance of ITO films was little changed by the plasma power, the prolonged treatment slightly increased the transmittance. The work function of ITO film was changed from 4.67 eV to 5.66 eV at the plasma treatment conditions of 300 W and 60 min.

Bilaterally Microstructured Thin Polydimethylsiloxane Film Production

DEFF Research Database (Denmark)

Vudayagiri, Sindhu; Yu, Liyun; Hassouneh, Suzan Sager

2015-01-01

Thin PDMS films with complex microstructures are used in the manufacturing of dielectric electro active polymer (DEAP) actuators, sensors and generators, to protect the metal electrode from large strains and to assure controlled actuation. The current manufacturing process at Danfoss Polypower A/...

Determination of acoustic properties of thin polymer films utilizing the frequency dependence of the reflection coefficient of ultrasound.

Science.gov (United States)

Tohmyoh, Hironori; Sakamoto, Yuhei

2015-11-01

This paper reports on a technique to measure the acoustic properties of a thin polymer film utilizing the frequency dependence of the reflection coefficient of ultrasound reflected back from a system comprising a reflection plate, the film, and a material that covers the film. The frequency components of the echo reflected from the back of the plate, where the film is attached, take their minimum values at the resonant frequency, and from these frequency characteristics, the acoustic impedance, sound velocity, and the density of the film can be determined. We applied this technique to characterize an ion exchange membrane, which has high water absorbability, and successfully determined the acoustic properties of the membrane without getting it wet.

Dual-Input AND Gate From Single-Channel Thin-Film FET

Science.gov (United States)

Miranda, F. A.; Pinto, N. J.; Perez, R.; Mueller, C. H.

2008-01-01

A regio-regular poly(3-hexylthiophene) (RRP3HT) thin-film transistor having a split-gate architecture has been fabricated on a doped silicon/silicon nitride substrate and characterized. RRP3HT is a semiconducting polymer that has a carrier mobility and on/off ratio when used in a field effect transistor (FET) configuration. This commercially available polymer is very soluble in common organic solvents and is easily processed to form uniform thin films. The most important polymer-based device fabricated and studied is the FET, since it forms the building block in logic circuits and switches for active matrix (light-emitting-diode) (LED) displays, smart cards, and radio frequency identification (RFID) cards.

Investigation of the RF pulse modulated plasma jet system during the deposition of Pb(Zr.sub.x./sub.Ti.sub.1-x./sub.)O.sub.3./sub. thin films on polymer substrates

Czech Academy of Sciences Publication Activity Database

Hubička, Zdeněk; Čada, Martin; Adámek, P.; Virostko, Petr; Olejníček, Jiří; Deyneka, Alexander; Jastrabík, Lubomír; Jurek, Karel; Suchaneck, G.; Guenther, M.; Gerlach, G.; Boháč, Petr

2005-01-01

Roč. 200, - (2005), s. 940-946 ISSN 0257-8972 R&D Projects: GA AV ČR(CZ) KJB1010302 Institutional research plan: CEZ:AV0Z10100522 Keywords : : PZT thin films * plasma jet * Langmuir probe * plasma impedance Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.646, year: 2005

The role of ultra-fast solvent evaporation on the directed self-assembly of block polymer thin films

Science.gov (United States)

Drapes, Chloe; Nelson, G.; Grant, M.; Wong, J.; Baruth, A.

The directed self-assembly of nano-structures in block polymer thin films viasolvent vapor annealing is complicated by several factors, including evaporation rate. Solvent vapor annealing exposes a disordered film to solvent(s) in the vapor phase, increasing mobility and tuning surface energy, with the intention of producing an ordered structure. Recent theoretical predictions reveal the solvent evaporation affects the resultant nano-structuring. In a competition between phase separation and kinetic trapping during drying, faster solvent removal can enhance the propagation of a given morphology into the bulk of the thin film down to the substrate. Recent construction of a purpose-built, computer controlled solvent vapor annealing chamber provides control over forced solvent evaporation down to 15 ms. This is accomplished using pneumatically actuated nitrogen flow into and out of the chamber. Furthermore, in situ spectral reflectance, with 10 ms temporal resolution, monitors the swelling and evaporation. Presently, cylinder-forming polystyrene-block-polylactide thin films were swollen with 40% (by volume) tetrahydrofuran, followed by immediate evaporation under a variety of designed conditions. This includes various evaporation times, ranging from 15 ms to several seconds, and four unique rate trajectories, including linear, exponential, and combinations. Atomic force microscopy reveals specific surface, free and substrate, morphologies of the resultant films, dependent on specific evaporation conditions. Funded by the Clare Boothe Luce Foundation and Nebraska EPSCoR.

A comparative study of the physical properties of Sb2S3 thin films treated with N2 AC plasma and thermal annealing in N2

International Nuclear Information System (INIS)

Calixto-Rodriguez, M.; Martinez, H.; Pena, Y.; Flores, O.; Esparza-Ponce, H.E.; Sanchez-Juarez, A.; Campos-Alvarez, J.; Reyes, P.

2010-01-01

As-deposited antimony sulfide thin films prepared by chemical bath deposition were treated with nitrogen AC plasma and thermal annealing in nitrogen atmosphere. The as-deposited, plasma treated, and thermally annealed antimony sulfide thin films have been characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy, scanning electron microscopy, atomic force microscopy, UV-vis spectroscopy, and electrical measurements. The results have shown that post-deposition treatments modify the crystalline structure, the morphology, and the optoelectronic properties of Sb 2 S 3 thin films. X-ray diffraction studies showed that the crystallinity of the films was improved in both cases. Atomic force microscopy studies showed that the change in the film morphology depends on the post-deposition treatment used. Optical emission spectroscopy (OES) analysis revealed the plasma etching on the surface of the film, this fact was corroborated by the energy dispersive X-ray spectroscopy analysis. The optical band gap of the films (E g ) decreased after post-deposition treatments (from 2.36 to 1.75 eV) due to the improvement in the grain sizes. The electrical resistivity of the Sb 2 S 3 thin films decreased from 10 8 to 10 6 Ω-cm after plasma treatments.

Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

Science.gov (United States)

Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

2016-01-01

In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

Inductively coupled hydrogen plasma processing of AZO thin films for heterojunction solar cell applications

International Nuclear Information System (INIS)

Zhou, H.P.; Xu, S.; Zhao, Z.; Xiang, Y.

2014-01-01

Highlights: • A high-density plasma reactor of inductively coupled plasma source is used in this work. • The conductivity and transmittance can be enhanced simultaneously in the hydrogen process. • The formation of additional donors and passivation due to the hydrogen plasma processing. • The photovoltaic improvement due to the improved AZO layer and hetero-interface quality in the solar cells. - Abstract: Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H 2 , aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration)

Fabrication and performance of polymer-nanocomposite anti-reflective thin films deposited by RIR-MAPLE

Energy Technology Data Exchange (ETDEWEB)

Singaravelu, S.; Mayo, D. C.; Park, H-. K.; Schriver, K. E.; Klopf, John M. [W& M, JLAB; Kelley, Michael J. [W& M; Haglund, R. F. [VANDERBILT

2014-07-01

Design of polymer anti-reflective (AR) optical coatings for plastic substrates is challenging because polymers exhibit a relatively narrow range of refractive indices. Here, we report synthesis of a four-layer AR stack using hybrid polymer: nanoparticle materials deposited by resonant infrared matrix-assisted pulsed laser evaporation. An Er: YAG laser ablated frozen solutions of a high-index composite containing TiO2 nanoparticles and poly(methylmethacrylate) (PMMA), alternating with a layer of PMMA. The optimized AR coatings, with thicknesses calculated using commercial software, yielded a coating for polycarbonate with transmission over 97 %, scattering <3 %, and a reflection coefficient below 0.5 % across the visible range, with a much smaller number of layers than would be predicted by a standard thin film calculation. The TiO2 nanoparticles contribute more to the enhanced refractive index of the high-index layers than can be accounted for by an effective medium model of the nanocomposite.

Atomic layer deposition of copper thin film and feasibility of deposition on inner walls of waveguides

Science.gov (United States)

Yuqing, XIONG; Hengjiao, GAO; Ni, REN; Zhongwei, LIU

2018-03-01

Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature, using copper(I)-N,N‧-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas. The influence of temperature, plasma power, mode of plasma, and pulse time, on the deposition rate of copper thin film, the purity of the film and the step coverage were studied. The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied. The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy, respectively. The square resistance of the thin film was also tested by a four-probe technique. On the basis of on-line diagnosis, a growth mechanism of copper thin film was put forward, and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films. A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.

Stages of polymer transformation during remote plasma oxidation (RPO) at atmospheric pressure

Science.gov (United States)

Luan, P.; Oehrlein, G. S.

2018-04-01

The interaction of cold temperature plasma sources with materials can be separated into two types: ‘direct’ and ‘remote’ treatments. Compared to the ‘direct’ treatment which involves energetic charged species along with short-lived, strongly oxidative neutral species, ‘remote’ treatment by the long-lived weakly oxidative species is less invasive and better for producing uniformly treated surfaces. In this paper, we examine the prototypical case of remote plasma oxidation (RPO) of polymer materials by employing a surface micro-discharge (in a N2/O2 mixture environment) treatment on polystyrene. Using material characterization techniques including real-time ellipsometry, x-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy, the time evolution of polymer film thickness, refractive index, surface, and bulk chemical composition were evaluated. These measurements revealed three consecutive stages of polymer transformation, i.e. surface adsorption and oxidation, bulk film permeation and thickness expansion followed by the material removal as a result of RPO. By correlating the observed film thickness changes with simultaneously obtained chemical information, we found that the three stages were due to the three effects of weakly oxidative species on polymers: (1) surface oxidation and nitrate (R-ONO2) chemisorption, (2) bulk oxidation, and (3) etching. Our results demonstrate that surface adsorption and oxidation, bulk oxidation, and etching can all happen during one continuous plasma treatment. We show that surface nitrate is only adsorbed on the top few nanometers of the polymer surface. The polymer film expansion also provided evidence for the diffusion and reaction of long-lived plasma species in the polymer bulk. Besides, we found that the remote plasma etched surface was relatively rich in O-C=O (ester or carboxylic acid). These findings clarify the roles of long-lived weakly oxidative plasma species on polymers and advance

Capillary levelling as a probe of rheology in polymer thin films

Science.gov (United States)

McGraw, Joshua D.; Jago, Nick M.; Dalnoki-Veress, Kari

2011-03-01

While measuring the rheology of bulk polymer systems is routine, when the size of a system becomes comparable to the molecular size, flow properties are poorly understood and hard to measure. Here, we present the results of experiments that are easily performed and can probe the rheological properties of polymer films that are mere tens of nanometres in thickness. We prepare glassy bilayer polymer films with height profiles well approximated by a step function. Upon annealing above the glass transition, broadening of the height profiles due to gradients in the Laplace pressure is observed. By validating the technique as a probe of the rheology with a range of molecular weights, we will show that this robust technique can be used to investigate the effects of confinement and interfaces on the rheology of ultrathin polymer films. Financial support from NSERC of Canada is gratefully acknowledged.

Cell adhesion to cathodic arc plasma deposited CrAlSiN thin films

Energy Technology Data Exchange (ETDEWEB)

Kim, Sun Kyu, E-mail: skim@ulsan.ac.kr [School of Materials Science and Engineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Pham, Vuong-Hung [Department of Materials Science and Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Kim, Chong-Hyun [Department of Food Science, Cornell University, Ithaca, NY 14853 (United States)

2012-07-01

Osteoblast cell response (cell adhesion, actin cytoskeleton and focal contact adhesion as well as cell proliferation) to CrN, CrAlSiN and Ti thin films was evaluated in vitro. Cell adhesion and actin stress fibers organization depended on the film composition significantly. Immunofluorescent staining of vinculin in osteoblast cells showed good focal contact adhesion on the CrAlSiN and Ti thin films but not on the CrN thin films. Cell proliferation was significantly greater on the CrAlSiN thin films as well as on Ti thin films than on the CrN thin films.

Vacuum arc plasma generation and thin film deposition from a TiB{sub 2} cathode

Energy Technology Data Exchange (ETDEWEB)

Zhirkov, Igor, E-mail: igozh@ifm.liu.se; Petruhins, Andrejs; Naslund, Lars-Ake; Rosen, Johanna [Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Kolozsvári, Szilard; Polcik, Peter [PLANSEE Composite Materials GmbH, Siebenbürgerstraße 23, 86983 Lechbruck am See (Germany)

2015-11-02

We have studied the utilization of TiB{sub 2} cathodes for thin film deposition in a DC vacuum arc system. We present a route for attaining a stable, reproducible, and fully ionized plasma flux of Ti and B by removal of the external magnetic field, which leads to dissipation of the vacuum arc discharge and an increased active surface area of the cathode. Applying a magnetic field resulted in instability and cracking, consistent with the previous reports. Plasma analysis shows average energies of 115 and 26 eV, average ion charge states of 2.1 and 1.1 for Ti and B, respectively, and a plasma ion composition of approximately 50% Ti and 50% B. This is consistent with measured resulting film composition from X-ray photoelectron spectroscopy, suggesting a negligible contribution of neutrals and macroparticles to the film growth. Also, despite the observations of macroparticle generation, the film surface is very smooth. These results are of importance for the utilization of cathodic arc as a method for synthesis of metal borides.

Tailoring electronic structure of polyazomethines thin films

OpenAIRE

J. Weszka; B. Hajduk; M. Domański; M. Chwastek; J. Jurusik; B. Jarząbek; H. Bednarski; P. Jarka

2010-01-01

Purpose: The aim of this work is to show how electronic properties of polyazomethine thin films deposited by chemical vapor deposition method (CVD) can be tailored by manipulating technological parameters of pristine films preparation as well as modifying them while the as-prepared films put into iodine atmosphere.Design/methodology/approach: The recent achievements in the field of designing and preparation methods to be used while preparing polymer photovoltaic solar cells or optoelectronic ...

Thin films of metal-organic compounds and metal nanoparticle ...

Indian Academy of Sciences (India)

Optical limiting capability of the nanoparticle-embedded polymer film is demonstrated. Keywords. Polar crystal; uniaxial orientational order; thin film; second harmonic gen- eration; silver ... able content of metal nanoparticles would be of considerable value from an appli- ... polar chain and perpendicular to it [10].

Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

International Nuclear Information System (INIS)

Bolat, Sami; Tekcan, Burak; Ozgit-Akgun, Cagla; Biyikli, Necmi; Okyay, Ali Kemal

2015-01-01

Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N 2 /H 2 PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH 3 PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N 2 :H 2 ambient

Niobium thin film coating on a 500-MHz copper cavity by plasma deposition

Energy Technology Data Exchange (ETDEWEB)

Haipeng Wang; Genfa Wu; H. Phillips; Robert Rimmer; Anne-Marie Valente; Andy Wu

2005-05-16

A system using an Electron Cyclotron Resonance (ECR) plasma source for the deposition of a thin niobium film inside a copper cavity for superconducting accelerator applications has been designed and is being constructed. The system uses a 500-MHz copper cavity as both substrate and vacuum chamber. The ECR plasma will be created to produce direct niobium ion deposition. The central cylindrical grid is DC biased to control the deposition energy. This paper describes the design of several subcomponents including the vacuum chamber, RF supply, biasing grid and magnet coils. Operational parameters are compared between an operating sample deposition system and this system. Engineering work progress toward the first plasma creation will be reported here.

Oxygen Reduction Reaction Activity of Platinum Thin Films with Different Densities

Energy Technology Data Exchange (ETDEWEB)

Ergul, Busra; Begum, Mahbuba; Kariuki, Nancy; Myers, Deborah J.; Karabacak, Tansel

2017-08-24

Platinum thin films with different densities were grown on glassy carbon electrodes by high pressure sputtering deposition and evaluated as oxygen reduction reaction catalysts for polymer electrolyte fuel cells using cyclic voltammetry and rotating disk electrode techniques in aqueous perchloric acid electrolyte. The electrochemically active surface area, ORR mass activity (MA) and specific activity (SA) of the thin film electrodes were obtained. MA and SA were found to be higher for low-density films than for high-density film.

Hydrogen uptake in alumina thin films synthesized from an aluminum plasma stream in an oxygen ambient

International Nuclear Information System (INIS)

Schneider, J.M.; Anders, A.; Hjoervarsson, B.; Petrov, I.; Macak, K.; Helmersson, U.; Sundgren, J.

1999-01-01

We describe the hydrogen uptake during the synthesis of alumina films from H 2 O present in the high vacuum gas background. The hydrogen concentration in the films was determined by the 1 H( 15 N,αγ) 12 C nuclear resonance reaction. Furthermore, we show the presence of hydrogen ions in the plasma stream by time-of-flight mass spectrometry. The hydrogen content increased in both the film and the plasma stream, as the oxygen partial pressure was increased. On the basis of these measurements and thermodynamic considerations, we suggest that an aluminum oxide hydroxide compound is formed, both on the cathode surface as well as in the film. The large scatter in the data reported in the literature for refractive index and chemical stability of alumina thin films can be explained on the basis of the suggested aluminum oxide hydroxide formation. copyright 1999 American Institute of Physics

Effect of silane/hydrogen ratio on microcrystalline silicon thin films by remote inductively coupled plasma

Science.gov (United States)

Guo, Y. N.; Wei, D. Y.; Xiao, S. Q.; Huang, S. Y.; Zhou, H. P.; Xu, S.

2013-05-01

Hydrogenated microcrystalline silicon (μc-Si:H) thin films were prepared by remote low frequency inductively coupled plasma (ICP) chemical vapor deposition system, and the effect of silane/hydrogen ratio on the microstructure and electrical properties of μc-Si:H films was systematically investigated. As silane/hydrogen ratio increases, the crystalline volume fraction Fc decreases and the ratio of the intensity of (220) peak to that of (111) peak drops as silane flow rate is increased. The FTIR result indicates that the μc-Si:H films prepared by remote ICP have a high optical response with a low hydrogen content, which is in favor of reducing light-induced degradation effect. Furthermore, the processing window of the phase transition region for remote ICP is much wider than that for typical ICP. The photosensitivity of μc-Si:H films can exceed 100 at the transition region and this ensures the possibility of the fabrication of microcrystalline silicon thin film solar cells with a open-circuit voltage of about 700 mV.

Spectral and time-resolved properties of photoinduced hydroxyquinolines doped thin polymer films

Science.gov (United States)

Mehata, Mohan Singh

2018-01-01

Quinoline and its derivatives have a wide range of biological and pharmacological activities. Quinoline ring is used to design functional materials (quinoline derivatives) for OLEDs and field-induce electrooptics. It possesses antibacterial, antifungal, antimalarial, cardiotonic, anthelmintic, anti-inflammatory, anticonvulsant and analgesic activity. Here, we have examined photoexcitation dynamics of 6-hydroxyquinoline (6-HQ) doped in polymer films of polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA) and cellulose acetate (CA) at atmospheric conditions. The absorption maximum of 6-HQ in polymer films was observed at 333 ± 1 nm, whereas fluorescence (FL) maximum fell in the range of 365-371 nm. In PVA film, in addition to the typical FL, a band maximum at 432 nm appeared as a result of an excited-state intermolecular proton transfer (ESIPT) reaction facilitated in the hydrogen-bonded complex formed in the ground state between 6-HQ:PVA. The multi-exponential decay behavior of 6-HQ in all the three polymer films indicates a nanoscale heterogeneity of the polymer environments.

Dry etching of LaNiO3 thin films using inductively coupled plasma

International Nuclear Information System (INIS)

Kim, Gwan-Ha; Kim, Dong-Pyo; Kim, Kyoung-Tae; Kim, Chang-Il; Lee, Cheol-In; Kim, Tae-Hyung

2006-01-01

The etching characteristics of LaNiO 3 (LNO) thin films and SiO 2 in Cl 2 /Ar plasma were investigated. LNO etch rates decreased with increasing Cl 2 fraction in Ar plasma and the working pressure. Langmuir probe measurement showed a noticeable influence of Cl 2 /Ar mixing ratio on electron temperature, electron density, and ion current density. The modeling of volume kinetics for charged particles and OES measurements for neutral atoms indicated monotonous changes of both densities and fluxes of active species such as chlorine atoms and positive ions. The LNO etch rate behavior may be explained by physical mechanisms

Thin film microelectrodes for electrochemical detection of neurotransmitters

DEFF Research Database (Denmark)

Larsen, Simon Tylsgaard

An important signaling process in the nervous system is the release of chemical messengers called neurotransmitters from neurons. In this thesis alternative thin film electrode materials for applications targeting electrochemical detection of neurotransmitters in chip devices were evaluated...... and conductive polymer microelectrodes made of Pedot:Pss were also fabricated and used successfully to measure transmitter release from cells. The use of different thin film electrodes for low-noise amperometric measurements of single events of transmitter release from neuronal cells was studied....... For this application a very low current noise is needed together with a large temporal resolution. It was shown, that resistive and capacitive properties of thin film electrode materials are determining their usefulness in low-noise amperometric measurements. An analytical expression for the noise was derived...

Laser deposition and direct-writing of thermoelectric misfit cobaltite thin films

Science.gov (United States)

Chen, Jikun; Palla-Papavlu, Alexandra; Li, Yulong; Chen, Lidong; Shi, Xun; Döbeli, Max; Stender, Dieter; Populoh, Sascha; Xie, Wenjie; Weidenkaff, Anke; Schneider, Christof W.; Wokaun, Alexander; Lippert, Thomas

2014-06-01

A two-step process combining pulsed laser deposition of calcium cobaltite thin films and a subsequent laser induced forward transfer as micro-pixel is demonstrated as a direct writing approach of micro-scale thin film structures for potential applications in thermoelectric micro-devices. To achieve the desired thermo-electric properties of the cobaltite thin film, the laser induced plasma properties have been characterized utilizing plasma mass spectrometry establishing a direct correlation to the corresponding film composition and structure. The introduction of a platinum sacrificial layer when growing the oxide thin film enables a damage-free laser transfer of calcium cobaltite thereby preserving the film composition and crystallinity as well as the shape integrity of the as-transferred pixels. The demonstrated direct writing approach simplifies the fabrication of micro-devices and provides a large degree of flexibility in designing and fabricating fully functional thermoelectric micro-devices.