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The effects of the spin coating process parameters on the thickness of the SiOx layer of the BOPP/SiOx composite film were investigated. When the concentration of tetraethoxysilane (TEOS) increased from 12.5 vol% to 55% vol%, the SiOx thickness increased from about 80 nm to 470 nm. In the sol time range of 1.5 h to 5 h the SiOx layer thickness reached a maximum at about 4 h and the change of the thickness roughly matched the change of the silica colloidal sphere sizes in sol. When the spin-coating speed of the dispensing stage increased from 450 r/min to 500 r/min, the SiOx layer thickness drastically decreased from about 1.67 μm to 400 nm. While the spin-coating speed of the thinning and drying stage went up to 1200 r/min, the SiOx layer thickness was in the range of 330 nm to 390 nm. It was also found that the SiOx layer thickness was almost increased linearly from about 500 nm to 1.02 μm with the ratio of the commercial silica colloidal to the TEOS from 0.2 to 1.0. The water contact angles decreased to about 23.0° for the BOPP/Si-Sol composite film with 1.67 μm SiOx layer and about 4.0° for the BOPP/mixing Si-Sol composite film with 1.02 μm SiOx layer. Compared to BOPP, the light transparency of the BOPP/Si-Sol composite films decreased by about 5.5% with the SiOx layer from about 80 nm to 1.67 μm and by 7.0% for the BOPP/mixing Si-Sol composite film with the SiOx layer from about 350 nm to 1.02 μm respectively. 相似文献
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紫外光照处理对TiO2膜光伏性能的影响 总被引:3,自引:0,他引:3
近年来人们利用纳米晶TiO2电极取代普通的TiO2电极[1],使其太阳能电池的光电转换效率得到很大提高.纳米晶TiO2电极具有大量表面态,在化学上表现为Ti3+或Ti—OH,对于光生电荷的分离过程和迁移过程有重要影响.这些表面化学结构的变化可能会导致TiO2的光伏性能的变化.1997年Fujishima等[2]用紫外光照射TiO2膜使它具有超亲水的性质,结构分析表明,超亲水的原因在于光照使TiO2膜的表面形成Ti—OH[3].因此,在光照处理的同时可能会导致TiO2的光伏性的变化.本文对紫外光照处理TiO2膜的光伏性能进行了研究,并结合光诱导TiO2的亲水性变化对光伏性能变化的原因进行了讨论. 相似文献
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光催化抗雾膜材料的制备及其亲水性研究 总被引:27,自引:1,他引:27
采用改进的Sol-Gel技术制备负载型复合光催化抗雾膜材料,AES和接触角测定等手段研究了膜厚度、热处理条件及光照条件等因素对材料亲水性的影响,光催化抗雾膜的亲水性受控于TiO2的晶型和膜比表面,大比表面和高锐钛矿含量可降低膜对水的接触角,膜的厚度通过改变催化剂量和光利用率影响材料的亲水性。膜材料亲水性保持或恢复效果相当。 相似文献
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利用光热材料的太阳能水蒸发技术是一种绿色、 环保地解决淡水资源短缺的重要技术, 但光热材料的制备成本、 蒸发效率和热损失等因素限制了其推广应用. 本文采用一锅法制备了聚乙烯醇载银海绵(AgNPs/PVA)太阳能界面蒸发器, 并研究了AgNPs含量对AgNPs/PVA在太阳能驱动水蒸发过程中光热性能的影响. 研究结果表明, 当AgNPs的质量为PVA的10%时, 制备的AgNPs/PVA在1 kW/m 2的太阳光强度下具有最优的蒸发速率, 水蒸发速率可达1.62 kg?m ?2?h ?1, 为纯水(0.42 kg?m ?2?h ?1)的3.9倍. 本文制备的AgNPs/PVA具有制备工艺简单、 亲水性能优良和蒸发性能良好的特点, 在太阳能驱动水蒸发领域具有较大的应用前景. 相似文献
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Long range correlation concerning hydrophilicity and flexibility along a number of 80 calcium binding protein sequences is confirmed by using spectral analysis and detrended fluctuations analysis methods, as well as by Hurst exponent calculations. There are no significant differences between the correlation properties concerning these properties for the two structural subfamilies, extended and compact, of the calcium binding proteins and they are also similar with the correlation properties revealed by other investigated proteins. This result sustains the hypothesis that the long range correlation of hydrophilicity and flexibility along the chain is a common feature of proteins. 相似文献
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Electrophoretic mobility and contact angle measurements have been made on alatrofloxacin mesylate and its formulations which were protected from or exposed to light, and its degradation product compound (F). In aqueous solution, the light-protected alatrofloxacin mesylate had a zeta-potential of +19 mV, a negligible electron-acceptor (γi+) surface tension parameter and an electron-donor surface tension parameter γi−=32.5 mJ m−2, which was higher than that of water. This caused the particles to be very hydrophilic and to form very stable suspensions in aqueous solution due, mainly, to a net Lewis acid–base (polar) repulsion. After the suspensions were exposed to light, the zeta-potential of the degradation product increassed to +37.8 mV, but the electron-donor surface tension parameter decreased to γi−=8 mJ m−2, making the molecules or particles very hydrophobic and causing them to flocculate. The energies of attraction in the latter case were mainly hydrophobic (90%) with about 10% resulting from van der Waals forces. 相似文献
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Low-temperature CO2 plasma is used for the treatment of poly-ethersulfone (PES), polyamide (PA) and poly-phenylene ethersulfone (PPE) ultrafiltration membranes. This has led to significant enhancement of the wetting characteristics of the membrane surface as is shown by contact angle measurements and Fourier transform infrared (FTIR) spectrum analysis of the treated membranes. Changes in the physical characteristics of the surface, such as tensile property, surface roughness, etc. are quantified by tensile strength measurement and atomic force microscopy (AFM), respectively. An increase in the measured values of the di-electric constants further highlights the hydrophilic modification of the surface. A series of ultrafiltration experiments using a BSA solution of known concentration under different operating conditions is performed and the deposition thicknesses over the membrane surface during ultrafiltration are measured directly using image analyzing microscopy. The results clearly demonstrate that a plasma treated PES membrane is more hydrophilic with smoother surface and resists fouling leading to significant enhancement of permeate flux. 相似文献
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Aki Uehara Masanao Imai Isao Suzuki 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,324(1-3):79-85
The hydrophobic interfacial characterization of sugar–ester alcohol W/O microemulsion was investigated in order to develop a suitable design for reaction media. A W/O microemulsion system was prepared as a combination of sugar–ester, DK-ester-F-110 with alcohol as a cosolvent. The diameter of the sub-micron-sized water pool, the hydrophobicity of the water pool, and the fluidity of the micro-interface were studied to analyze the reactivity of Rhizopus delemar lipase in lipid hydrolysis. The diameter of the sub-micron sized water pool was measured by dynamic laser light scattering. It was proportional to the 0.33 power of Wsoln and decayed with increasing alcohol concentration. The initial reaction rate of the hydrolysis of triolein in W/O microemulsion depended on the solubilized water content. The hydrophilic character of the micro-water pool was estimated from the fluorescence wavelength indicated by Coumarin 343. The maximum initial reaction rate appeared at 450–460 nm. The fluidity of the micro-interface was investigated by fluorescence anisotropy using TMA-DPH. A suitable physicochemical reaction condition for high reactivity to occur was found, satisfying both the hydrophilicity and the fluidity of the micro-interface. 相似文献
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Stefanie Breukers Christer L. Øpstad Hans‐Richard Sliwka Vassilia Partali 《Helvetica chimica acta》2009,92(9):1741-1747
The oft‐claimed ‘good’ water solubility of the food color norbixin ( 3 ) could not be confirmed. In contrast, the potassium salt 5 of norbixin formed suitable dispersions. The surface and aggregation properties of salt 5 were investigated and compared with other naturally occurring and synthetic hydrophilic carotenoids (Table). 相似文献