Thermoplastic starch modified with polyurethane microparticles: Effects of hydrophilicity of polyurethane prepolymer

It is important to chemically modify starch in an effective way. In this study, a series of polyurethane prepolymers (PUP) using 2,2‐dimethylol propionic acid (DMPA) as hydrophilic chain extender was synthesized and then used to modify starch by intensive mixing to obtain modified thermoplastic starch (TPS). The structure and properties of the modified TPS were investigated. The results showed that the elongation at break of the modified TPS increased from 5.4 to 9.8% with the content of PUP in modified TPS increasing from 10 to 20%, suggesting the PUP played an important role in the enhancement of the flexibility of the modified TPS sheet. The reaction ratio of PUP used for preparing the modified TPS was 98.5 ± 0.03%, indicating the modification was conducted efficiently because the multifunctional groups of polyurethane microparticles dramatically improved the reaction probability of the PUP modifier. The modified TPS prepared with PUP by adding DMPA showed increasing viscosity and decreasing contact angle due to the hydrophilicity of DMPA.     

直接键合硅片的亲水处理及其表征

硅片直接键合技术的关键在于硅片表面的亲水处理,本文分析了亲水处理之微观机理,从界（表）面物理化学角度讨论了接触角对硅片表面亲水性的表征及其准确测量方法,并测量了常用清洗液的接触角大小。     

A facile route to end-functionalized poly(N-isopropylacrylamide) brushes synthesized by surface-initiated SET-LRP

In this study, the facile synthesis of well defined, end-functionalized poly(N-isopropylacrylamide) [poly(NIPAM)] brushes was achieved by surface-initiated single-electron transfer living radical polymerization (SET-LRP). Surface-initiated SET-LRP of N-isopropylacrylamide in the presence of cysteamine chain transfer agent was conducted via Cu(0) generated in situ by the disproportionation of Cu(I) to Cu(0) and Cu(II) in N,N-dimethylformamide at 90 °C. Initially, silicon surfaces were modified with 2-bromopropionyl bromide (2-BPB). [Poly(NIPAM)] brushes with amine end-group were then synthesized via surface-initiated SET-LRP from the immobilized 2-BPB. Various characterization techniques including ellipsometry, grazing angle-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and water contact-angle measurements were used to characterize the immobilization of 2-BPB on the silicon wafer and the subsequent polymer with amine end-group formation. The addition of free 2-BPB initiator was required for the formation of free polymer chains in solution. The free polymer chains were isolated and used to estimate the molecular weights and polydispersity index of chains attached to the surface. Although there are several chemicals methods for post-polymerization transformation of the halide chain end to amine groups, this study mainly provides a method for in situ functionalization of poly(NIPAM) brushes.     

基于恢复亲水性的江南城市滨水空间分类及更新方法研究

历史上江南水乡城镇空间呈现高度的亲水性特征。而在近年城市扩张中滨水空间被忽视,城市亲水意向消逝。城市滨水空间的传统价值虽然减弱了,但新的价值增长了,在城市更新中需要恢复江南城市的亲水性特色。针对不同的滨水空间类型应采用不同的更新方法。首先根据河道尺度大小、滨河地块性质将滨水空间归纳为四个类型;然后对应这些类型提出有针对性的设计方法,通过增加滨水空间的活力而复兴江南城市的亲水性特色。     

城市滨水区商业空间设计研究 --以常熟市滨江邻里中心商业地块设计为例

城市滨水区空间的设计与开发该文在分析国内外城市滨水区建设成功案例的基础上,归纳出滨水空间设计的特点,并以常熟滨江邻里中心商业地块的设计为例,就城市滨水区商业空间的设计与开发作一些有益的探讨。     

Polyvinylidene fluoride ultrafiltration membrane blended with nano-ZnO particle for photo-catalysis self-cleaning

A novel photo-catalysis polyvinylidene fluoride ultrafiltration membrane was successfully fabricated via phase inversion method. The membrane matrix was supplemented with nano-ZnO of different content for membrane modification. Filtration experiments, contact angle measurements, scanning electron microscope/energy dispersive X-ray spectrometer analysis, and mechanical tests were conducted to characterize the modified membranes. The photo-catalysis tests clearly showed that the modified PVDF membranes had significant photo-catalysis self-cleaning capability. PVDF-1 (adding 1.0% nano-ZnO with PVDF) membranes achieved 94.8% water flux recovery after exposure to low-pressure 10 W UV-C mercury lamp irradiation for 30 min, whereas the raw membrane only reached 63.3% recovery. The implantation of nano-ZnO on the inner surface of the membrane (i.e., the pore wall) may have been responsible for the enhancement of the photo-catalysis self-cleaning property. The pure water flux of the PVDF-1.5 (adding 1.5% nano-ZnO with PVDF) membrane was nearly five times as great as that of pure PVDF. Supplementation of nano-ZnO could improve the mechanical properties of the membrane, but excessive supplementation of nano-ZnO could cause a decline in the membrane mechanical properties.     

Characterization of metal (Ba, Al, Si, V, and W)-incorporated TiO2 and toluene photodecomposition in the presence of H2O

This study focused on toluene photodecomposition in the presence of H₂O over metal (Ba, Al, Si, V, and W)-incorporated TiO₂. The nanometer-sized, metal-TiO₂ photocatalyst samples, including Ba²⁺, Al³⁺, Si⁴⁺, V⁵⁺, and W⁶⁺ ions, were prepared by using the solvothermal method. The X-ray photoelectron spectroscopy (XPS) results showed that the Ti-OH peak, which indicates hydrophilicity, increased with increasing Al and Si ion components but decreased with increasing Ba, V, and W ion components. The contact angles were distributed over the range of 0–10° on almost all films (200-nm thick) after irradiation for 2 h, and in particular approached 0° on the Al-TiO₂ and Si-TiO₂ nanometer-sized films after just 30 min. The toluene (100 ppm) photodecomposition in the continuous system increased in the order of Al-TiO₂>Si-TiO₂>pure TiO₂>W-TiO₂>Ba-TiO₂>V-TiO₂, and the maximum toluene conversion rate achieved was 45% over Al-TiO₂ film after 120 min. The toluene conversion remarkably increased; however, over all photocatalysts, with H₂O addition during the toluene photo-decomposed reaction, and in particular, the conversion reached up to 90% after 120 min over Al-TiO₂ and Si-TiO₂ with increased hydrophilicity. After photoreaction for 24 h, minimal carbon was deposited on the photocatalyst under both reaction conditions, with and without H₂O addition, although the deposited carbon amounts were smaller for the former. These results confirmed that the hydrophilicity of the photocatalyst had a greater effect on toluene decomposition, while the photocatalytic deactivation could be retarded by H₂O supplementation during toluene decomposition.     

Particles from bird feather: A novel application of an ionic liquid and waste resource

The dissolution and regeneration of the waste chicken feathers in an ionic liquid of 1-butyl-3-methylimi-dazolium chloride ([BMIM]Cl) were demonstrated for preparing chicken feather based particles. The structure and properties of the regenerated chicken feathers were investigated by FT-IR, XRD, SEM, BET and water contact angle. The crystallinity of the regenerated chicken feathers was decreased, and the content of β-sheet was 31.71%, which was clearly lower than the raw feather (47.19%). The surface property of chicken feather changed from hydrophobicity to hydrophilicity after regenerated from [BMIM]Cl as indicated by the change of the water contact angle from 138 to 76°. The chicken feather particles regenerated from [BMIM]Cl showed an excellent efficiency (63.5–87.7%) for removing Cr(VI) ions in wastewater at the concentrations from 2 to 80 ppm. The Freundlich constant (k_F) for the adsorption of Cr(VI) ion by the particles of the regenerated chicken feather was four times larger than that of the raw chicken feather, the possible reason is the hydrophilic groups such as amino and carboxyl groups were tend to self-assemble towards surface when the dissolved CF were regenerated by water, amino group will partly hydrate to cationic amino and Cr(VI) ion occurs as an anion in the aqueous phase, so the cationic amino will adsorb the anionic Cr(VI) ion onto the RCF particles through electrostatic attraction. This work demonstrated a new application of the ionic liquid for dissolving chicken feather and a renewable application of waste chicken feather for removing Cr(VI) ion in water.     

Two-Functional Direct Current Sputtered Silver-Containing Titanium Dioxide Thin Films

The article reports on structure, mechanical, optical, photocatalytic and biocidal properties of Ti–Ag–O films. The Ti–Ag–O films were reactively sputter-deposited from a composed Ti/Ag target at different partial pressures of oxygen on unheated glass substrate held on floating potential U _fl. It was found that addition of ~2 at.% of Ag into TiO₂ film has no negative influence on UV-induced hydrophilicity of TiO₂ film. Thick (~1,500 nm) TiO₂/Ag films containing (200) anatase phase exhibit the best hydrophilicity with water droplet contact angle (WDCA) lower than 10° after UV irradiation for 20 min. Thick (~1,500 nm) TiO₂/Ag films exhibited a better UV-induced hydrophilicity compared to that of thinner (~700 nm) TiO2/Ag films. Further it was found that hydrophilic TiO₂/Ag films exhibit a strong biocidal effect under both the visible light and the UV irradiation with 100% killing efficiency of Escherichia coli ATCC 10536 after UV irradiation for 20 min. Reported results show that single layer of TiO₂ with Ag distributed in its whole volume exhibits, after UV irradiation, simultaneously two functions: (1) excellent hydrophilicity with WDCA < 10° and (2) strong power to kill E. coli even under visible light due to direct toxicity of Ag.     

聚酯磺酸盐的合成及其乳液的研究(Ⅱ)

２．４聚酯磺酸盐乳液的制备２．４．１聚酯磺酸盐的种类对乳液稳定性的影响乳液的制备方法、乳液类型的确定（润湿滤纸法）、稳定期的测定一参考文献［１２］。配比：聚酯磺酸盐／通用不饱和聚酯／苯乙烯／水＝１／１／１／３,所得乳液稳定性见表７和表８。２．４．２聚酯磺酸盐含量对乳液稳定性的影响配比：聚酯（包括聚酯磺酸盐）／苯乙烯／水＝２／１／３。聚酯磺酸盐含量指占聚酯重量百分率。所得结果见表９和表１０。２．４．３不同含水量对乳液稳定性的影响配比：聚酯磺酸盐／苯乙烯＝２／１,含水量指水占乳液重量百分率。用聚酯磺…