O/W型生漆光固化膜的理化性能

以漆酚(U)/聚乙烯醇(PVA)为混合乳化剂,借助相反转技术,将W/O型天然生漆转化成可直接用水稀释的O/W型生漆,用紫外光固化法使其固化成膜;采用红外光谱、扫描电镜、热分析等手段对该固化膜进行结构表征和性能测试。结果表明:在紫外光辐照下,O/W型生漆可在2min内快速固化成膜,固化膜具有优良的理化性能。     

Photoreactivity of poly(p-phenylphenylenevinylene)

Summary In films of poly(para-phenylphenylenevinylene) a photoreaction has been observed. The significant feature is a decrease of the fluorescence emission intensity during irradiation. It is assumed that a cycloaddition between C=C- double-bonds leads to crosslinks in the material.Under similar conditions of excitation a photoreaction has not been observed in poly(p-phenylenevinylene) prepared via the precursor-route.     

Patterning of Tin Oxide Film from Photoreactive Precursor Solutions Prepared via the Addition of N-Phenyldiethanolamine

Metallo-organic compounds were synthesized for the preparation of tin oxide fine patterning via the addition of alkanolamines. Tin(IV) isopropoxide was chemically modified with diethanolamine (DEA) and/or N -phenyl-diethanolamine (PhDEA). Then, the chemical stability and photoreactivity of the prepared metallo-organic compounds were compared. A tin precursor solution that was formed via the stepwise additions of both DEA and PhDEA showed good chemical stability in air and efficient photoreactivities under ultraviolet irradiation. The fine patterning of tin oxide was achieved successfully on a substrate, using the precursor solution.     

Fabrication of robust multilayer films by triggering the coupling reaction between phenol and primary amine groups with visible light irradiation

We prepared robust cross-linked (x-linked) multilayer films under visible light irradiation with the catalysis of a Ru(ii) complex. The x-linking is achieved by the coupling reaction between phenol group and primary amine group within the self-assembled multilayer films that were prepared beforehand. Three kinds of polymers, i.e., poly(4-vinylphenol), poly(allylamine) and poly(ethyleneimine), were selected as the model system to illustrate the concept of this strategy. Upon visible light irradiation, the chemical stability of the x-linked films towards solution etching was greatly enhanced. In previous studies, horseradish peroxidase (HRP) is often utilized to catalyze the C-C, C-O and C-N coupling structures, which is useful to prepare polymers, capsules and bulk hydrogels. We also tried to prepare the x-linked films by the catalysis of HRP. The comparison of the two methods suggests that the Ru(ii) complex method is more ideal for fabricating x-linked films. In addition, the photo-triggered chemical reaction within the films was confirmed by the solid-state (13)C NMR, XPS and FT-IR measurements. Without UV light irradiation or thermal treatment, this strategy brings many advantages. It is anticipated that this approach can be easily extended to the applications of the biological related fields in the future.     

Surface hydrophilic–hydrophobic property on transparent mesoporous silica thin films containing chromium oxide single-site photocatalyst

Using a sol–gel/spin-coating method with organic template, the transparent mesoporous silica thin films containing chromium oxide moieties can be prepared on quartz plate. The spectroscopic characterization has revealed that these thin films contain isolated and tetrahedrally coordinated chromium oxide moieties (single-site photocatalyst) in their frameworks. Even before UV light irradiation these Cr-containing mesoporous silica (CrMS) thin films have demonstrated a hydrophilic surface property more strongly than Cr-containing non-porous silica films and mesoporous silica thin films without chromium oxide. Furthermore, the Cr-containing mesoporous silica thin films showed the super-hydrophilic property not only under UV light irradiation but also even under visible light irradiation from a fluorescent lamp. In the presence of ethylene gas, the polyethylene was successfully formed on the surface of the CrMS thin film under UV light irradiation. After the formation of polyethylene the surface property of the CrMS thin film was converted into hydrophobic while keeping its transparency. The isolated and tetrahedrally coordinated chromium oxide moieties are responsible for these photo-induced surface reactions.     

UV reactive polymers for refractive index modulation based on the photo-Fries rearrangement

In this study we report on the synthesis and characterization of photoreactive polymers which display large changes in their refractive index upon UV irradiation. These polymers contain aromatic ester groups which undergo a photo-Fries rearrangement from aryl esters to hydroxyketones. The polymers under investigation were poly(4-acetoxystyrene) and two derivatives of polynorbornene, poly(bicyclo[2.2.1]hept-5-ene-2-carboxylic acid, phenyl ester) and poly(bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, diphenyl ester). The kinetics of the photoreaction was studied by FTIR spectroscopy. Ellipsometric measurements of thin films showed that the photo-Fries rearrangement causes a large increase of the refractive indices in these polymers (between +0.03 and +0.05). The modulation of the refractive index is of interest for applications in the field of optics and data storage. The photoreaction also leads to an increase in surface energy as evidenced by contact angle measurements with water and diiodomethane as test liquids.     

紫外光照射对掺铝氧化锌薄膜导电和透光性质的影响

本文采用光助溶胶—凝胶法制备了掺铝氧化锌(AZO)透明导电薄膜.研究了紫外光照射对薄膜导电性和透光性质的影响.结果表明:光照使薄膜的导电性显著提高,且光照后薄膜方阻的降低幅度随薄膜晶粒尺寸的减小而逐渐增加;而随着紫外光照射时间延长,薄膜的紫外吸收边蓝移,近红外区透光率降低.以上实验现象可能与表面吸附氧解吸引起的载流子浓度增加、迁移率升高以及分层退火处理形成的薄膜结构有关.     

Ultraviolet Patterning of Alkoxy-Derived Lithium Niobate Film

Patterned lithium niobate (LN) films were synthesized successfully from a precursor film containing 1-phenyl-1,3-butanedione (PBD) by ultraviolet (UV) irradiation. A LN precursor solution composed of lithium ethoxide and niobium ethoxide was modified with PBD in ethanol to form LiNb(OEt)_{6- n} (PBD) _n , which was designed to have a specific UV absorption at 330 nm. The precursor film began to crystallize at 400°C on sapphire C substrates. The UV absorption band at 330 nm in the precursor film decreased in intensity with increased exposure time to UV light. The patterned LN films crystallized at 550°C on sapphire C substrates showed a (006) preferred orientation.     

Self‐assembled multilayer films based on diazoresins studied by atomic force microscopy/friction force microscopy

The layer‐by‐layer self‐assembled NDR‐PSS (nitro‐containing diazoresin‐polysodium p‐styrenesulfonate) films were fabricated. The crosslinking structure formed from the conversion of ionic bond to covalent bond after UV irradiation, confirmed by small angle X‐ray diffraction. The roughness and microtribological properties of NDR‐PSS films were investigated by atomic force microscopy/friction force microscopy. The ordered multilayer films after photoreaction are better in microtribological performance than that of the monolayer film. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 631–638, 2000     

Functionalization of polypropylene film by radiation grafting of acryloyl chloride and subsequent esterification with Disperse Red 1

Polypropylene (PP) films were grafted with acryloyl chloride by γ‐irradiation, and the grafted films were reacted with an azo dye, Disperse Red 1. The films were characterized by X‐ray diffraction, scanning electron microscopy, atomic force microscopy, and differential scanning calorimetry. It was found that the grafting takes place first on the film surface, and with increase in the radiation dose the grafting penetrated inside of the film, decreasing the crystallinity of the PP film. The surface of the films was homogeneous, and a mesophase was observed for the film grafted with the dye through a polarized optical microscope. The dye underwent trans to cis photoreaction, whereby the red films became colorless by the irradiation of UV light at room temperature, although the color was recovered on standing, and more quickly when heated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 172–178, 2004     

紫外光辐射和微波辐射处理的纳米TiO2薄膜光催化性能研究

采用溶胶-凝胶(sol-gel)技术以工业偏钛酸为原料．载玻片为基体制备纳米TiO2薄膜。分别用紫外光辐射、微波辐射及热辐射(马福炉)对TiO2进行处理,研究了不同处理方式对纳米TiO2薄膜微结构参数的影响及结构参数与降解甲基橙光催化性能的关系。X射线衍射(XRD)研究说明三种处理方式得到在基片上具有[101]面择优取向的TiO2薄膜．其中热辐射为晶体膜,紫外光及微波为非晶膜。光催化实验结果为热辐射TiO2薄膜活性最好．微波辐射及紫外光辐射其次．但差异较小(3％),微波及紫外光辐射处理温度约100℃,尤其适用于低温材料基质,表明新的辐射方式可替代传统的热处理。     

A rapid approach to urushiol–copper(I) coordination polymer under UV irradiation

Urushiol–metal polymers have attracted more and more attention in China because of their wide applications as a heavy anticorrosive coating in chemical industry. They could also offer many novel properties, including catalytic activity, magnetic property, semiconductive properties, flame retarding performance, etc., and significant progresses have been achieved in synthesis and study on the mechanism of these polymers. In this paper, a rapid method for fabrication of urushiol–copper(I) coordination polymer was developed under UV irradiation within 2 min. The formation and thermo-stability of the cured films were characterized by ESR, XPS, FT-IR, TGA, etc. The results suggested the coordination occurred between copper(I) ion and oxygen under UV irradiation. In the course of UV irradiation, the hydroxyl groups on the phenyl ring of urushiol were dissociated to urushiol semiquinone, and then coordinated with copper(I) ions generated by deoxidization of copper(II) ion. At the same time, crosslinking reaction on the long aliphatic unsaturated side chain occurred to form polymer. TG analysis showed that the polymer had excellent thermo-stability.     

Preparation of positive photoreactive polyimides and their characterization

Polyimide precursors were synthesized from a diamine and a diacid chloride that was derived from the reactant with promellitic dianhydride and o-nitrobenzyl alcohol. Their thermal properties were studied in nitrogen using dynamic thermogravimetry, and the photoreaction mechanism was investigated by ultraviolet and infrared spectrophotometry. The polyimide precursors were spin-coated onto silicon wafers, prebaked, and then exposed to UV light from a high pressure Hg–Xe lamp. When the films were dipped into 2% aqueous KOH after irradiation, the exposed area dissolved forming high resolution patterns. Relative sensitivities of the polymers were determined.     

Preparation of Molybdenum, Vanadium, and Tungsten Oxide Thin Films from Self-Assembly Deposited Polyoxometalate–Alkylamine-Layered Hybrid Films

A novel, simple, and efficient route for preparing MoO₃, V₂O₅, and WO₃ films has been developed from layered polyoxometallate (POM)-alkylamine hybrid films by calcination. The highly ordered hybrid films were self-assembly deposited in a one-step process using clear precursor POM solutions, prepared by reacting layered MoO₃, V₂O₅, and WO₃·H₂O powders with hexylamine in the presence of water. The morphology of the resulting films can be tuned by removing the intercalated hexylamine molecules from the as-prepared hybrid films through UV irradiation before calcination.     

预处理对Ti02表面超亲水性的影响

在高湿度环境下，应用紫外光辐射对溶胶一凝胶Ti02薄膜预处理，经过预处理的薄膜烧结后具有快速光致高度亲水特性和良好的光催化活性，超亲水的薄膜能够吸附大量的酸性品红，在光照下薄膜将吸附的酸性品红逐渐降解掉．     

Photodegradation of o‐Cresol with Ag Deposited on TiO2 under Visible and UV Light Irradiation

This study investigated the effect of dosage of Ag on the characteristics of TiO₂, quantum yield, and temporal decomposition behavior of o‐cresol in an annular reactor under ultraviolet (UV) and visible light irradiation. In order to extend light absorption and minimize the rapid recombination during photoreaction, the Ag deposited on TiO₂ photocatalysts was prepared by a photodeposition process. The results of diffuse reflectance spectra (DRS) indicated that Ag deposited on TiO₂ promoted the optical absorption in the visible region and made it possible for it to be excited by visible light. The degradation rate of o‐cresol with 0.50 wt % Ag/TiO₂ under visible light irradiation was 2.0 times that with pure TiO₂.     

Light‐control birefringence of oriented poly(vinyl cinnamate) by UV irradiation

The research focused on realizing the birefringence of light‐control polymer films. The photoelastic birefringence exhibits when Poly (vinyl cinnamate) (PVCi) films are stretched below their glass transition temperature (T_g). The birefringence of PVCi decreases when the UV irradiation happens because the side chains of the PVCi photo‐react when the oriented films are exposed to UV light. A method to quantify the birefringence ability of the polymer films is created and verified. Using this method, the decrease of the birefringence through the UV irradiation is quantified. The result shows the birefringence of PVCi can be controlled by altering the UV irradiation time. In addition, oriented PVCi films of different esterification degrees were prepared and irradiated at different time, and the birefringence of them was studied to clarify the birefringence mechanism of light‐control polymer films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and characterization of UV‐curable ZnO/polymer nanocomposite films

A series of novel nano‐ZnO/polymer composite films with different ZnO contents was prepared through incorporation of pre‐made colloidal ZnO particles into monomer mixtures of urethane‐methacrylate oligomer and 2‐hydroxyethyl methacrylate, followed by ultraviolet (UV) radiation‐initiated polymerization. The colloidal ZnO nanoparticles with a diameter of 3–5 nm were synthesized from zinc acetate and lithium hydroxide in ethanol via a wet chemical method. In order to stabilize and immobilize the ZnO particles into the polymer matrix, the ZnO nanoparticles were further capped using 3‐(trimethoxysilyl)propyl methacrylate. Thermogravimetric analyses show that the ZnO nanoparticles were successfully incorporated into the polymer matrix and these ZnO/polymer composites have a good thermal stability. Transmission electron microscopy studies indicate the ZnO nanoparticles were uniformly dispersed in the polymer and they remained at the original size (3–5 nm) before immobilization. All nanocomposite films with ZnO particle contents from 1 to 15 wt% show good transparency in the visible region and luminescent properties. In addition, composite films with high ZnO content (>7 wt%) are able to absorb UV irradiation below 350 nm, indicating that these composite films exhibit good UV screening effects. Copyright © 2006 Society of Chemical Industry     

Efficient degradation of aqueous methyl orange over TiO2 and CdS electrodes using photoelectrocatalysis under UV and visible light irradiation

A highly efficient photoelectrocatalytic course was realized by combining TiO₂ and CdS films. The TiO₂ films were prepared using dc reactive magnetron sputtering method, and the CdS films were deposited by chemical bath deposition (CBD) method. The X-ray diffraction (XRD), Raman, field-emission scanning electron microscope (FESEM) were used to characterize the film structure and surface morphologies. The experiment results showed that the photoelectrocatalysis by using the TiO₂ and CdS films under double-beam irradiation of UV and visible lights had higher photocatalytic activity than the sum of photoelectrocatalysis solely using TiO₂ and CdS films.     

Nanocrystalline ZnO Thin Film Synthesis Using Glycerol in Aqueous Polymeric Precursor Processing

Synthesis of high-quality ZnO thin films via simple and cost effective processing technique is a major challenge. In this work, the preparation of nanocrystalline ZnO thin films by a novel polymeric precursor processing using glycerol as chelating agent is presented. The process has advantages of being cost-effective and environment friendly. ZnO thin films were prepared by a single spin-coating deposition of aqueous polymeric precursor prepared with zinc nitrate [Zn(NO₃)₂] and glycerol as chelating agent. The thermal decomposition of polymeric precursors was studied by thermogravimetric analysis and Fourier transform infrared (FTIR) spectroscopy. Annealing of these films were performed over the range of 300°–600°C, and the effect of annealing on the degree of crystallization, surface morphology, crystallite size, and optical properties was investigated. X-ray diffraction analysis shows that the thin films are polycrystalline with wurtzite structure. The thin films are 80% dense, have crack free microstructure, and transparency of >85% in the visible region. These films exhibit absorption edge at 375 nm. On measuring at room temperature, the optical band gap energy of ZnO thin films, annealed at 450° and 600°C, was determined to be 3.295 and 3.267 eV. Room temperature photoluminescence spectra of these films show strong UV emission and a broad yellow-green emission in the range 525–600 nm. The intensity of UV emission peak increases with increase in annealing temperature that is attributed to an improvement in crystallinity.