Non-Conducting Poly(O-Aminophenol) Films in the Field of the Bioelectrochemistry

The practical use of non-conducting poly(o-aminophenol) (POAP) films in the field of the bioelectrochemistry is discussed in this paper. Particular emphasis is given to the effects of applied potential, solution pH and interferents on the response current of biosensors based on POAP.

Compatibility and Properties of Biodegradable Blend Films with Gelatin and Poly(vinyl alcohol)

The blend films with gelatin and poly（vinyl alcohol） （PVA） were prepared by a solution casting method. The compatibility between gelatin and PVA in the blend films was investigated. The transmittance, Fourier-transform infrared spectroscopy （FTIR）, x-ray diffraction （XRD）, thermogravimetry analysis （TG）, and differential scanning calorimetry （DSC） were employed to characterize the resultant blend films. According to optic result, the opacity of the blend film at the ratio of 20/80 （w/w, Gel to PVA） was the lowest, indicating the best compatibility between Gel and PVA at the ratio. The results oflR, XRD, DSC, and TG revealed an intensive interaction and good compatibility between them in the blend film at the ratio. The mechanical properties and solubility showed that PVA content in the blend films obviously affected the elongation at break and solubility. The mechanical properties and water resistance of gelatin film may be improved by the introduetion of PVA.

Characterization and tribological investigation of self-assembled trimethoxysilyl-functionalized poly(phthalazinone ether ketone)thin films on glass substrates

Trimethoxysilyl-functionalized PPEK（PKGS） films had been designed to serve as wear resistant coatings for silicon surfaces. These surface films were formed by a dip-coating technique applied to self-assembled monolayers（SAMs）.The formation and wetting behavior of PKGS films were characterized by means of contact angle measurement.The friction coefficient of the film prepared is very low（about 0.1）,and the anti-wear behavior is good,with a lack of failure after sliding over 1800 s.

FABRICATION AND AFM/FFM STUDIES OF C_(60)-CONTAINING POLYELECTROLYTE SELF-ASSEMBLED FILMS

An initial investigation on the roughness and frictional properties of the self-assembled thin films from polyelectrolytes is presented. Star-shaped C-60-Poly(styrene-maleic anhydride) was successful prepared. The multilayer thin films have been fabricated on mica with diazoresin as the cationic polyelectrolyte and hydrolyzed star-shaped C-60-poly(styrene-maleic anhydride) as the anionic polyelectrolyte via self-assembly technique. The crosslinking structure of the films is formed from the conversion of ionic bond to covalent bond after UV irradiation. AFM/FFM investigations provide insights into the roughness and frictional properties on a microscale. The roughness depends strongly on the number of film layers in the case of C-60-containing films. The frictional forces of the films exhibited a well behaved non-linear relationship in response to the change of applied load. It supports the prediction of enhanced load-bearing property Of C60-containing thin films.

Structure and Optical Behavior of Nanocomposite Hybrid Films of Well Monodispersed ZnO Nanoparticles into Poly (vinylpyrrolidone)

We fabricated an inorganic-polymeric photoluminescent thin film based on ZnO nanoparticles, which were grown directly in the poly（vinylpyrrolidone） （PVP） matrix. The microstructure, composition, thermal stability, and the temperature-dependent photoluminescence of the thin film were investigated. X-ray diffraction （XRD） and transmission electron microscopy （TEM） results indicated that all the ZnO nanoparticles with a polycrys talline hexagonal wurzite structure were well separated from each other and were dispersed in the polymeric matrix homogeneously and randomly. Raman spectrum （Raman） showed a typical resonant multi-phonon process within the hybrid thin film. The shifts of infrared bands for PVP in the hybrid film should be attributed to strong coulombic interaction between ZnO and polymeric matrix. The stability of the hybrid film and the effect of the perturbation of ZnO on the stability were determined by means of the thermogravimetric analysis （TG） and differential thermal analysis （DTA）. The ultraviolet-visible adsorption （UV-vis） showed distinct excitonic features. The photoluminescent spectrum （PL） of the ZnO nanoparticles modified by PVP molecules showed markedly enhanced ultraviolet emission and significantly reduced green emission, which was due to the Perfect surface passivation of ZnO nanoparticles. Temperature dependent photoluminescent spectrum studies suggested that the ultraviolet emission was associated with bound exciton recombination.

NOVEL HYPERBRANCHED POLY(AMINE-ESTER) FILMS: PREPARATION, CHARACTERIZATION AND PROPERTIES

Crosslinked film of hyperbranched poly（amine-ester） （HPAE） was prepared by crosslinking its terminal hydroxyl groups with glutaraldehyde （GA）. Atom force microscope （AFM） and scanning electron microscope （SEM） reveals that they have smooth surfaces, dense and homogenous matrices. It was found that the water static contact angle is smaller than 41.7°, the tensile strength is higher than 8.9 MPa, the elongation at break is higher than 5.1%, the swelling degree is higher than 42% in water, and the Bovine hemoglobin （Hb） adsorption is relatively low. These results indicate that the crosslinked HPAE films might have some potential applications in many areas.

Electrochemistry and Electrocatalysis with Hemoglobin in DHP-PDDA Surfactant-Polymer Multibilayer Composite Films

Polyionic complex DHP-PDDA was prepared by reacting anionic surfactant dihexadecyl phosphate (DHP) with polycationic poly(diallyldimethyl ammonium) (PDDA). Thin films made from DHP-PDDA with incorporated hemoglobin (Hb) on pyrolytic graphite (PG) electrodes were characterized by electrochemistry and other techniques.

IONIC CONDUCTIVITY IN CROSSLINKED POLY (METHYLSILOXANE-g-ETHYLENE OXIDE) NETWORK FILMS CONTAINING LITHIUM PERCHLORATE

Polymer electrolytes based on poly (methylsiloxane-g-ethylene oxide) and LiClO_4 have been prepared. The network films crosslinked by a crosslinking agent are found to exhibit a considerably high ionic conductivity of about 10^(-4) Scm^(-1) at room temperature and have good flexibility.

PROPERTIES OF SILK FIBROIN/POLY(ETHYLENE GLYCOL)400 BLEND FILMS

The blend film of silk fibroin (SF) and poly(ethylene glycol)400 (PEG400) with a blend ratio of 2/1 (wt/wt) wasprepared simply by dropping a little PEG400 into the SF solution and then casting the mixed aqueous solution at 50℃. Theresulting film exhibited much better mechanical properties in the dry and wet state than SF itself, owing to theconformational change of SF in the blends from the random coil to the β-sheet structure and intermolecular hydrogen bondformation between SF and PEG400. Thermogravimetric analysis showed that the initial thermal decomposition temperatureof the blend film was 170℃, which was 80℃ lower than that of SF (250℃) and 20℃ higher than that of PEG400 (150℃),and indicated a Strong interaction between two components of the blend. No crystalline peaks were observed in the X-raydiffraction curve of the blend film. Cell culture test showed that SF/PEG400 was a suitable substrate for the growth of humanumbilical vein endothelial cells (HUVEC).

Synthesis of Metal/Poly(diphenylsilylenemethylene) Nanocomposite Thin Films by Pulsed Laser Ablation

A new technique to synthesize poly（diphenylsilylenemethylene） （PDPhSM） matrix nanocomposite thin films containing metal nanoparticles such as Ni, AI, Zn, and W produced by pulsed laser ablation has been developed. First, 1,1,3,3-tetra- phenyl-1,3-disilacyclobutane （TPDC） films were deposited on 4 cm2 silicon substrates cut from c-Si wafers by conventional vacuum evaporation under a pressure of 4.0×10^-3 Pa; then metal nanoparticles were deposited onto the TPDC films by pulsed laser ablation; finally the TPDC films with metal nanoparticles were heated in an electric furnace in an air atmosphere at 553 K for 10 rain to induce ring-opening polymerization of TPDC. The results indicate that it is easy to synthesize metal/ PDPhSM nanocomposite thin films by pulsed laser ablation. The morphologies and size of metal nanoparticles are closely related to the kinds of metal. Also, the polymerization efficiency depends on the kinds of metal nanoparticles deposited on the TPDC monomer films by pulsed laser ablation. In addition, The laser ablated metal nanoparticles penetrate into the TPDC monomer films during pulsed laser ablation while the DC sputtered metal nanoparticles just lay on the surface of TPDC films.

In-Situ Composition and Luminescence of Europium and Terbium Coordination Polymers/PEMA Hybrid Thick Films

Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate （ EMA ）. With the polymerization of EMA monomer and the formation of europium and terbium coordination polymers of pyridiae- 3-carboxylic acid, the transparent hybrid thick fihns composed of [ Eu（ NIC ）3 ]n （ [ Tb（ NIC）3 ]n ） and poly ethyl mettuwrylate （ PEMA ） have been prepared. The luminescence properties and energy transfer of these polymeric composites were studied with absorption spectra, fluorescent excitation trod emission spectra in detail. All the hybrid thick films composed of terbium coordination polymer show the characteristic strong green emission of terbium ions, which implies the same energy transfer mechanism as the pure complex and the hybrid composite film is a suitable sabstrate for the luminescence of terbium ions. In the range of camposing concentration of luminescent species （0.01,0.025,0.05,0.1 mmol /15 mL EMA ）, emission intensities increase with the increasing of corresponding composing concentration and the concentration quenching effect does not take place.

IONIC CONDUCTIVITY OF POLY (β-ALKOXYCARBONYLETHYLMETHYLSILOXANE)-LiClO_4 CROSSLINKED FILMS

Poly (β-carboxyethylmethylsiloxane)-LiClO_4 and poly (β-alkoxylethylmethylsiloxane)-LiClO_4 crosslinked fllms have been prepared. The ionic conductivity of the films depends on the polymer species, concentration of lithium perchlorate, temperature and content of crosslinking agent. The effect of high polar organic solvent 1, 4-butyrolactone on the ionic conductivity and mechanical properties of poly (β-carhoxyethylmethylsiloxane )-LiClO_4 system was also investignied.

Preparation of High-Quality Poly-Si Films by a Solid Phase Crystallizing Method

A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 /μm for substrate temperature at 300 ℃ and annealed at 550℃ for 3 hours.

Effects of Substrate Temperature on the Growth of Polycrystalline Si Films Deposited with SiH_4+Ar

Polycrystalline silicon （poly-Si） films were deposited using Ar diluted SiH4 gaseous mixture by electron cyclotron resonance plasma-enhanced chemical vapor deposition （ECR-PECVD）. The effects of the substrate temperature on deposition rate, crystallinity, grain size and the configuration of H existing in poly-Si film were investigated. The results show that, comparing with H2 dilution, Ar dilution could significantly decrease the concentration of H on the growing surface. When the substrate temperature increased, the deposition rate increased and the concentration of H decreased monotonously, but the crystallinity and the grain size of poly-Si films exhibited sophisticated trends. It is proposed that the crystallinity of the films is determined by a competing balance of the self-diffusion activity of Si atoms and the deposition rate. At substrate temperature of 200℃, the deposited film exhibits the maximum poly-Si volume fraction of 79%. Based on these results, higher substrate temperature is suggested to prepare the poly-Si films with advanced stability and compromised crystallinity at high deposition rate.

Effect of Ar on Polycrystalline Si Films Deposited by ECR-PECVD using SiH_4

In this paper, polycrystalline silicon films were deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition （ECR-PECVD） using SiH4/Ar and SiH4/H2 gaseous mixture. Effects of argon flow rate on the deposition efficiency and the film property were investigated by comparing with H2. The results indicated that the deposition rate of using Ar as discharge gas was 1.5-2 times higher than that of using H2, while the preferred orientations and the grain sizes of the films were analogous. Film crystallinity increased with the increase of Ar flow rate. Optimized flow ratio of SiH4 to Ar was obtained as F（SiH4）： F（Ar）=10：70 for the highest deposition rate.

OBSERVATION ON DEFECTS IN POLYCRYSTALLINE SILICON THIN FILMS

Polycrystalline silicon thin films were prepared by RTCVD (rapid thermal chemica l vapor deposition) method on several substrates such as SSP (silicon sheet from powder) ribbon, poly-Si wafer and mono-Si wafer. Intra-granular defects such as stacking faults, twins and microstructure defects were investigated on thin fil ms by scan electron microscopy (SEM) technique.

Formation of Poly-Si Films on Glass Substrates by Using Microwave Plasma Heating and Fabrication of TFT’s on the Films

We have developed an apparatus for producing high-density hydrogen plasma. The atomic hydrogen density was 3.0 × 1021 m?3 at a pressure of 30 Pa, a microwave power of 1000 W, and a hydrogen gas flow rate of 5 sccm. We confirmed that the temperatures of tungsten films increased to above 1000?C within 5 s when they were exposed to hydrogen plasma formed using the apparatus. We applied this phenomenon to the selective heat treatment of tungsten films deposited on amorphous silicon films on glass substrates and formed polycrystalline silicon films. To utilize this method, we can perform the crystalline process only on device regions. TFTs were fabricated on the polycrystalline silicon films and the electron mobilities of 60 cm2/Vs were obtained.

Antimicrobial Expanded Polytetrafluoroethylene Film Prepared by 3-ray Radiation Induced Grafting of Poly（acrylic acid）

The simultaneous γ-ray-radiation-induced grafting polymerization of acrylic acid on ex- panded polytetrafluoroethylene （ePTFE） film was investigated. It was found that the degree of grafting （DG） of poly（acrylic acid） （PAA） can be controlled by the monomer concentration, absorbed dose, and dose rate under an optimal inhibitor concentration of [Fe2＋]=18 mmol/L. SEM observation showed that the macroporous structure in ePTFE films would be covered gradually with the increase of the DG of PAA. The prepared ePTFE-g-PAA film was im- mersed in a neutral silver nitrate solution to fabricate an ePTFE-g-PAA/Ag hybrid film after the addition of NaBH4 as a reduction agent of Ag＋ to Ag atom. SEM, XRD, and XPS results proved that Ag nanoparticles with a size of several tens of nanometers to 100 nanometers were in situ immobilized on ePTFE film. The loading capacity of Ag nanoparticles could be tuned by the DG of PAA, and determined by thermal gravimetric analysis. The quart- titative antibacterial activity of the obtained ePTFE-g-PAA/Ag hybrid films was measured using counting plate method. It can kill all the Escherichia coli in the suspension in 1 h. Moreover, this excellent antibacterial activity can last at least for 4 h. This work provides a facile and practical way to make ePTFE meet the demanding antimicrobial requirement in more and more practical application areas.

Enhanced Electron Transfer for Hemoglobin in 2C_(12)N^+PVS-Composite Films Modified on Pyrolytic Graphite Electrodes

Stable thin films made from polyionic complex 2C12N+PVS- with incorporated Hb on PG electrodes were characterized by electrochemistry. The electron transfer between Hb and PG electrodes was greatly facilitated in microenvironment of 2C12N+PVS- films. The Hb-2C12N+PVS-films could be used to catalytically reduce trichloroacetic acid.

Direct Electrochemistry of Hemoglobin in Layer-by-layer {PDDA/Hb}_n Films Assembled on Pyrolytic Graphite Electrodes

Layer-by-layer {PDDA/Hb}(n) films were assembled by means of alternate adsorption of positively charged poly(diallyldimethyl ammonium) (PDDA) and negatively charged hemoglobin (Hb) at pH 9.2 from their aqueous solutions on pyrolytic graphite (PG) electrodes. Film growth during adsorption cycles was demonstrated by cyclic voltammetry and UV-Vis spectroscopy. Direct electrochemistry of Hb in {PDDA/Hb}(n) films on PG was studied.