A photosensitive copolymer for UV-curable electrodeposition coatings

A series of photosensitive random copolymers (UPDHES) were prepared by introducing acrylate groups onto the side chain of the copolymer backbone of N, N-domethyl amimethyl methacrylate (DMAEMA), 2-hydroxypropyl acrylate (HEA), 2-ethylhexyl acrylate (EHA), and styrene (St) (PDHES). The molecular structure of UPDHES was characterized by FTIR, 1HNMR and GPC. The photopolymerization kinetics of UPDHES with different C=C content was investigated using real time FTIR in which it was found that the UPDHES system had notable photosensitivity. The effect of C=C content on the properties of cured films were studied by evaluating various film properties such as thermal stability, glass transition temperature and tensile properties. The thermal degradation of cured films was investigated via thermogravimetric analysis/infrared spectrometry (TGA-IR). Thus a series of UV-curable electrodeposition coatings with good photosensitivity and mechanical properties were prepared from a low-cost photosensitive random copolymer.     

UV-curing of hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO2 dispersion and TGA/FTIR study of cured films

UV-curable hyperbranched polyurethane acrylate-polyurethane diacrylate/SiO₂ dispersion (HBPUA-PUDA/SiO₂) was prepared with isophorone diisocyanate (IPDI), hyperbranched polyester Boltorn H20 (H20), hydroxy-ethyl acrylate (HEA), polyethyleneglycol (PEG-200) and nano-SiO₂. The UV curing kinetics of the films was investigated by FTIR. The results show that the curing speed of the films increases with the adding of nano-SiO₂ and decreases with the adding of PUDA due to the slower chain movement. The thermal stability of the HBPUA-PUDA/SiO₂ films was studied by using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA/FTIR). The results show that all films exhibit two degradation stages located at about 320 and 440 °C corresponding to the degradation for hard segments of urethane-acrylate and the degradation for soft segment and polyester core. In addition, the results from the analysis of TGA/FTIR also indicate that the decomposition temperature of HBPUA-PUDA/SiO₂ film is 15 °C higher than that obtained for pure polymer. The degradation mechanism was proposed according to TGA/FTIR results.     

Improved visible transparency of SIO<Subscript>2</Subscript>/ZNO:AL /CEO<Subscript>2</Subscript>-TIO<Subscript>2</Subscript>/SIO<Subscript>2</Subscript> multilayer films with high UV absorption and infrared reflection rate

New visible transparent, UV absorption, and high infrared reflection properties have been realized by depositing multilayer SiO₂/ZnO: Al/CeO₂-TiO₂/SiO₂ films onto glass substrates at low temperature by radio frequency magnetron sputtering. Optimum thickness of SiO₂, ZnO: Al (ZAO) and CeO₂-TiO₂ (CTO) films were designed with the aid of thin film design software. The degree of antireflection can be controlled by adjusting the thickness and refractive index. The outer SiO₂ film can diminish the interference coloring and increase the transparency; the inner SiO₂ film improves the adhesion of the coating on the glass substrate and prevents Ca²⁺, Na⁺ in the glass substrate from entering the ZAO film. The average transmittance in the visible light range increases by nearly 18%-20%, as compared to double layer ZAO/CTO films. And the films display high infrared reflection rate of above 75% in the wavelength range of 10-25 μm and good UV absorption (> 98%) properties. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. The triple functional films with high UV absorption, antireflective and high infrared reflection rate will adapt to application in flat panel display and architectural coating glass, automotive glass, with diminishing light pollution as well as decreasing eye fatigue and increasing comfort.     

Influence of thickness on the properties of solution-derived LiMn<Subscript>2</Subscript>O<Subscript>4</Subscript> thin films

LiMn₂O₄ thin films of different thickness were derived from solution deposition and heat treated by rapid thermal annealing. The phase identification and surface morphology were studied by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the films were examined by galvanostatic charge-discharge experiments and electrochemical impedance spectroscopy. LiMn₂O₄ thin films of different thickness derived from solution deposition and rapid thermal annealing are homogeneous and crack free with the grain size between 20 nm and 50 nm. The specific capacity of these films is between 42 and 47 μAh·cm²·μm⁻¹. The capacity decreases with the increase of discharge current density. The capacity loss per cycle increases from 0.012% to 0.16% after being cycled 50 times as the film thickness increases from 0.18 μm to 1.04 μm. The lithium diffusion coefficients of these films are in the same order of 10⁻¹¹ cm²·s⁻¹.     

Preparation and electrical properties of BaPbO3 thin film

BaPbO3 thin films were deposited on Al2O3 substrates by sol-gel spin-coating and rapid thermal annealing. The microstructure and phase of BaPbO3 thin films were determined by X-ray diffractometry, scanning electrons microscopy and energy dispersive X-ray spectrometry. The influence of annealing temperature and annealing time on sheet resistance of the thin films was investigated. The results show that heat treatment, including annealing temperature and time, causes notable change in molar ratio of Pb to Ba, resulting in the variations of sheet resistance. The variation of electrical properties demonstrates that the surface state of the film changes from two-dimensional behavior to three-dimensional behavior with the increase of film thickness. Crack-free BaPbO3 thin films with grain size of 90 nm can be obtained by a rapid thermal annealing at 700 ℃ for 10 min. And the BaPbO3 films with a thickness of 2.5 μm has a sheet resistance of 35 Ω·-1.     

Characterization and Electrochemical Properties of LiMn2O4 Thin Films Prepared by Solution Deposition

1 IntroductionThin-filmlithium-ion batteries have attracted greatattention of researchfor possible use inimplantable medi-cal devices , CMOS-based integrated circuits ,radio fre-quency (RF) identification tags for inventory control andanti-theft protection[1],etc. Li Mn2O4thin films , aspromising cathode materials for thin-filmlithium-ion bat-teries, have been prepared by a few methods such aspulsedlaser deposition[2 ,3],electrospraying[4-9],RF mag-netron sputtering[10], laser ablation[11]…     

Effect of the sputtering parameters on the structure and properties of Cu<Subscript>3</Subscript>N thin film materials

Copper nitride (Cu₃N) thin films were successfully deposited on glass substrates by reactive radio frequency magnetron sputtering. The effects of sputtering parameters on the structure and properties of the films were studied. The experimental results show that with increasing of RF power and nitrogen partial pressure, the preferential crystalline orientation of Cu₃N film is changed from (111) to (100). With increasing of substrate temperature from 70 °C to 200 °C, the film phase is changed from Cu₃N phase to Cu. With increasing sputtering power from 80 W to 120 W, the optical energy decreases from 1.85 eV to 1.41 eV while the electrical resistivity increases from 1.45 ×10² Ω · cm to 2.99 × 10³ Ω · cm, respectively.     

Effect of heat-treatment on crystalline phase and UV absorption of 60CeO2-40TiO2 thin films by magnetron sputtering

60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin film with the largest UV cut-off wavelength. The sample films with CeO2:TiO2=60:40 were heated at 773 K, 873 K, 973 K for 30 min. These films are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy and spectrometer (XPS). XRD analysis proves that the addition of TiO2 to CeO2 changed the crystalline state of CeO2. But the UV absorption effect of CeO2-TiO2 films with CeO2 crystallite phase is inferior to that of the amorphous phase CeO2-TiO2 films. XPS analysis also indicates that the amorphous phase CeO2-TiO2 films have the most Ce3+ content in these films. Amorphous phase and crystalline phase of the CeO2-TiO2 films have different effects on UV absorption of the thin films.     

ZnO films on transferable and low thermal resistance graphite substrate grown by ultrasonic spray pyrolysis

ZnO thin films were deposited on graphite substrates by ultrasonic spray pyrolysis method with Zn(CH 3 COO) 2 ·2H 2 O aqueous solution as precursor. The crystalline structure, morphology, and optical properties of the as-grown ZnO films were investigated systematically as a function of deposition temperature and growth time. Near-band edge ultraviolet(UV) emission was observed in room temperature photoluminescence spectra for the optimized samples, yet the usually observed defect related deep level emissions were nearly undetectable, indicating that high optical quality ZnO thin fi lms could be achieved via this ultrasonic spray pyrolysis method. Considering the features of transferable and low thermal resistance of the graphite substrates, the achievement will be of special interest for the development of high-power semiconductor devices with suffi cient power durability.     

Construction of amperometric glucose biosensor based on <Emphasis Type="Italic">in-situ</Emphasis> fabricated hierarchical meso-macroporous SiO<Subscript>2</Subscript> modified Au film electrodes

Gold nanoparticles (GNPs) modified hierarchical meso-macroporous (HMMP) SiO₂ layer on the surface of Au film electrode was developed as a novel enzyme immobilization matrix for biosensors construction. HMMP SiO₂-Au bilayer film electrodes were in-situ fabricated with magnetron sputtering process and templating method. The as-prepared HMMP SiO₂ films were characterized by SEM, TEM, and cyclic voltammetry (CV). The modified layer of HMMP SiO₂ has interconnected pore channels, and the sizes of macropores and mesopores are about 330 nm and 9 nm, respectively. The HMMP SiO₂ modified gold film electrodes not only have no diffusion barrier for electrochemical probes, but also exhibit good electrochemical properties. In addition, the activity and stability of the immobilized enzyme can be commendably retained in HMMP SiO₂. The biosensor exhibits an excellent bioelectrocatalytic response to glucose with a linear range of 1.0×10^-4 M-1.0×10^-2 M, high sensitivity of 18.0 μA·mM^-1·cm^-2, as well as good reproducibility and stability.     

Hyperbranched Polyarylenes from Copolycyclotrimerization

High molecular weight hyperbranched polyarylenes were synthesized in high yields by one-pot copolycyclotrimerizations of 2,5-diethynylthiophene (1), 4,4' -biphenyldiyne (2) and 2,7-diethynylfluorenes (3) with l-heptyne (4) and 1-dodecyne (5) using TaCl5·Ph4Sn catalysts in toluene. The structures and properties of the polymers were characterized and evaluated by 1R, NMR, TGA, UV, fluorescence and optical limiting analyses. All the polymers possess high thermal stability and emit strong blue light upon UV irradiation, whose intensities are higher than that from poly( 1 -phenyl-1 -octyne) ( PPO) , a well-known highly luminescent disubstitut-ed polyacetylene. Little aggregation-induced red shift in the photoluminescence is observed in the thin films of the polymers.     

St/BA/MAA/AA/VAC复合乳液的合成及其应用

采用半连续乳液种子聚合法合成苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸(MAA)、丙烯酸(AA)、醋酸乙烯酯(VAc)的复合乳液。分析了丙烯酸对乳液电解质性能的影响,引发剂对聚合反应转化率的影响及乳化剂含量对乳液粘度的影响。通过正交试验确定组分的适当配比。该共聚乳液的粘度及固体含量符合要求,稳定性好,性能价格比高。应用表明:用此乳液配制成地毯乳胶,胶膜具有良好的机械性能。     

St/BA/MAA/AA/VAC复合乳液的合成及其应用

采用半连续乳液种子聚合法合成苯乙烯（St）、丙烯酸丁酯（BA）、甲基丙烯酸 （MAA）、丙烯酸（AA）、醋酸乙烯酯 （VAc）的复合乳液.分析了丙烯酸对乳液电解质性能的影响,引发剂对聚合反应转化率的影响及乳化剂含量对乳液粘度的影响.通过正交试验确定组分的适当配比.该共聚乳液的粘度及固体含量符合要求,稳定性好, 性能价格比高.应用表明：用此乳液配制成地毯乳胶,胶膜具有良好的机械性能.     

丙烯酸酯改性水性聚氨酯的制备及性能研究

采用种子溶胀乳液聚合法,以水性聚氨酯为种子,丙烯酸酯为单体,制备了2种水性聚氨酯丙烯酸酯复合乳液,考察了粒径、运动黏度、耐溶剂性以及热稳定性对改性前后乳液及胶膜的性能影响,并进行了红外光谱分析.结果表明:经丙烯酸酯改性后的丙烯酸酯-聚氨酯复合乳液,在耐溶剂性、热稳定性等方面均有显著提高;丙烯酸酯-水性聚氨酯复合乳液中,都存在着氢键行为,氢键促进二者的相容性和共混.     

Comprehensive optimization of electrical and optical properties for ATO films prepared by pulsed laser deposition

Antimony doped tin oxide(ATO) thin films have been prepared by pulsed laser deposition(PLD) method.The intrinsic effect of Sb dopant,including the Sb content,transition degree between Sb~(3+) and Sb~(5+) and crystallinity on the electrical and optical properties of the ATO thin films is mainly investigated.It is suggested that the transition degree of Sb~(3+) towards Sb~(5+)(Sb~(5+)/Sb~(3+) ratio) is determined by Sb content.When the Sb content is increased to 12 at%,the Sb~(5+)/Sb~(3+) ratio reaches the highest value of 2.05,corresponding to the resistivity of 2.70×10~(-3) Ω·cm.Meanwhile,the Burstein-Moss effect caused by the increase of carrier concentration is observed and the band gap of the ATO thin films is broadened to 4.0 eV when the Sb content is increased to 12 at%,corresponding to the highest average optical transmittance of 92%.Comprehensively considering the combination of electrical and optical properties,the ATO thin films deposited with Sb content of 12 at%exhibit the best properties with the highest "figure of merit" of 3.85×10~(-3) Ω~(-1).Finally,an antimony selenide(Sb_2Se_3) heterojunction solar cell prototype with the ATO thin film as the anode has been prepared,and a power conversion efficiency of 0.83%has been achieved.     

Effect of MnO<Subscript>2</Subscript> on properties of SiC-mullite composite ceramics for solar sensible thermal storage

For improving the properties of SiC-mullite composite ceramics used for solar sensible thermal storage, MnO₂ was introduced as sintering additive when preparing. The composite ceramics were synthesized by using SiC, andalusite, α-Al₂O₃ as the starting materials with non-contact graphite-buried sintering method. Phase composition and microstructure of the composites were investigated by XRD and SEM, and the effect of MnO₂ on the properties of SiC composites was studied. Results indicated that samples SM1 with 0.2 wt% MnO₂ addition achieved the optimum properties: bending strength of 70.96 MPa, heat capacity of 1.02 J·(g·K)^-1, thermal conductivity of 9.05 W·(m·K)^-1. Proper addition of MnO₂ was found to weaken the volume effect of the composites and improve the thermal shock resistance with an increased rate of 27.84% for bending strength after 30 cycles of thermal shock (air cooling from 1 100 °C to RT).     

Self-cleaning glass coated with Fe^3＋ -TiO2 thin film

The self-cleaning glass coated with Fe^3 -TiO2 photocatalytic thin film was prepared by sol-gel process from the system Ti(OC4H9),-NH(C2H4OH)2-C2H5OH-H2O containing FeCl3. The microstructure and properties of the film were studied using differential thermal analysis-thermogravimetry(DTA-TG), X-ray diffration (XRD) and scanning electron microscope(SEM). The transmittance of the self-cleaning glass was measured by using UV-Vis spectrometer. The effects of content of Fe^3 and the thickness of Fe^3 -TiO2 thin film on the photocatalytic ac-tivity were examined. The results show that the photocatalytic thin films are mainly composed of Fe3O4 and TiO2 particles within 10-100 nm. The appropriate amount of Fe^3 is effective for improving the photocatalytic activities of TiO2. The best photocatalytic activity is obtained when the molar ratio of Fe^3 to TiO2 is 0. 005 and the glass is coated with 9 layers.     

Influence of argon gas pressure on the ZnO:Al films deposited on flexible TPT substrates at room temperature by magnetron sputtering

Aluminium doped ZnO thin films(ZnO︰Al) were deposited on transparent polymer substrates at room temperature by rf magnetron sputtering method from a ZnO target with Al2O3 of 2.0 wt%. Argon gas pressure varied from 0.5 Pa to 2.5 Pa with radio frequency power of 120 W. XRD results showed that all the ZnO︰Al films had a polycrystalline hexagonal structure and a (002) preferred orientation with the c-axis perpendicular to the substrate. The grain sizes of the films were 6.3-14.8 nm.SEM images indicated the ZnO︰Al film with low Argon gas pressure was denser and the deposition rate of the films depended strongly on the Argon gas pressure, increasing firstly and then decreasing with increasing the pressure. The highest deposition rate was 5.2 nm/min at 1 Pa. The optical transmittance of the ZnO︰Al films increased and the blue shift of the absorption edge appeared when the Argon gas pressure increased. The highest transmittance of obtained ZnO︰Al films at 2.5 Pa was about 85% in the visible region. The electrical properties of the films were worsened with the increase of the Argon gas power from 1 Pa to 2.5 Pa. The resistivity of obtained film at 1.0 Pa was 2.79×10-2 Ω·cm.     

Effects of N<Subscript>2</Subscript> pressure on the structural and electrical properties of tin films deposited by laser molecular beam epitaxy

Titanium nitride (TiN) films were deposited on Si(100) substrates by laser molecular beam epitaxy(LMBE), and their properties of structure and resistivity with varying N₂ pressure were investigated. The results showed that atomically flat TiN films with layer-by-layer growth mode were successfully grown on Si(100) substrates, and (200) was the preferred orientation. With the increasing of N₂ pressure, the N/Ti ratio gradually increased and the diffraction peak progressively shifted towards lower diffraction angle. At pressure of 0.1 Pa, stoichiometric TiN film was formed which exhibited the characteristic diffraction angle of (200) plane. All films showed high reflectance to infrared spectrum and the films with overstoichiometry and understoichiometry had a higher resistivity owing to the surface particles and lattice distortion, while the stoichiometric TiN film depicted the minimum resistivity, around 19 μΩ·cm.     

Lithium Instertion in poly (ethylene oxide )/MoO3 Xerogel Nanocomposite Films

The nanocomposite films were prepared by direct intercalation of poly (ethylene oxide) and PEO into MoO3 xerogel via sol-gel route,The electrochromic behavior and the chemical conditionws of Li^ ions were investigated by cyclic voltammograms,UV-visible spectral transmittance and XPS,The tesults show that the cycling efficiency and the reversibility of insertion/extraciton of Li^ ions in (PEO)1 MoO3 .nH2O nanocomposite film were improved.The intercalation of PEO into MoO3 xerogel modulated the wavelength range of electrochromism and enhanced the electrochromic efficiney,Two different chemical conditions of Li^ ions existing in the interlayer and interstitial positions of MoO3 lattice were observed in MoO3 XEROGEL AND (PEO)1 MoO3.nH2O naocomposite films.