聚乙烯醇载银海绵的制备及界面光热驱动水蒸发性能

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.     

二氧化碳基脂肪族聚碳酸酯的功能化研究进展

简要介绍了二氧化碳基塑料的工业化进程,同时针对当前二氧化碳共聚物结构中缺少可反应基团、难以进行化学修饰导致的品种和功能单一、亲水性差等问题,介绍了二氧化碳基脂肪族聚碳酸酯的功能化研究进展,主要包括侧链含有双键、碳酸酯键和液晶基团的侧基功能化二氧化碳共聚物的合成与性能研究,以及二氧化碳共聚物的亲水性调制和刺激响应行为探索,试图为丰富二氧化碳基聚碳酸酯结构和性能提供借鉴.     

Super-hydrophilic properties of TiO2-DLC nanocomposite films fabricated by the simple electrochemical process

Anatase TiO₂ nanoparticles incorporated DLC films were successfully deposited on single crystalline silicon substrates by the electrolysis of TiO₂-methanol solution under ambient atmospheric pressure and low temperature. Anatase TiO₂ nanoparticles were embedded into amorphous carbon matrix, forming the typical nanocrystalline/amorphous nanocomposite films, confirmed by transmission electron microscopy (TEM). TiO₂ incorporation effectively increased the sp³-hybridized carbon concentration in the composite film, and further regulated the microstructure and surface morphology. Furthermore, the static contact testing completely displayed, TiO₂ incorporation got the composite films super-hydrophilic, which fundamentally improved the wetting ability of DLC film.     

胶原／磷酰胆碱复合膜的制备和性能研究

用静电纺丝-溶液浇注法制备胶原／聚2-甲基丙烯酰氧基乙基磷酰胆碱（pMPC）双层复合膜。用核磁共振波谱仪（NMR）、傅里叶变换红外光谱仪（FTIR）、热重分析仪（TG／DTG）分别表征了pMPC的化学结构、胶原／pMPC分子间的相互作用和共混相容性,用环境扫描电子显微镜（SEM）、X射线光电子能谱仪（XPS）、静态接触...     

Correlation of SiO x layer thickness and properties of BOPP/SiO x composite films with spin coating process parameters

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.     

Long range correlation of hydrophilicity and flexibility along the calcium binding protein chains

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.     

Application of the extended DLVO theory—the stability of alatrofloxacin mesylate solutions

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 (γ_i⁺) surface tension parameter and an electron-donor surface tension parameter γ_i⁻=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 γ_i⁻=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.     

不同临界保留因子下天然有机物亲疏水组分光谱特性

吸附树脂层析法是表征环境水样有机物亲疏水组分分布的常用方法。作为柱层析的基本参数,临界保留因子对亲疏水物质的吸附及分离效果具有潜在影响。以河北某水库的水样为例,将有机物分为亲水物(HIS)、疏水酸(HOB)、疏水碱(HOA)和疏水中性物(HON),考察了在不同临界保留因子分离条件下(k′_cr=5, 10, 25, 50, 100)亲疏水组分有机物含量分布,并着重考察了其光谱学特性。研究发现,亲疏水组分的浓度分布取决于k′_cr值的设置,疏水组分的比例和疏水程度随k′_cr的增大而增大。在250~280 nm波长范围内,亲水组分HIS的紫外吸光度随k′_cr的增高而增高,而疏水组分HOA和HOB则呈现相反趋势,亲水与疏水组分之间的紫外光谱差异性随k′_cr增大而增大。此外,疏水组分单位质量浓度的吸光度对k′_cr的取值敏感,推测k′_cr可能影响所得组分的芳香族官能团性质。进一步考察了各组分的三维荧光光谱,并采用荧光区域积分和荧光指数对图谱进行解析。结果表明,亲疏水组分的荧光峰形态、荧光区域分布和荧光团密度与k′_cr值有关,荧光指数BIX,HIX_em和Peak T/C对k′_cr的取值敏感,说明k′_cr可能对所得组分的具体化学组成乃至迁移转化行为产生影响。因此在分离并表征环境水样的亲疏水组分分布时,应特别注意临界保留因子的设置并明确标明其取值。     

Hydrophilic Carotenoids: Surface Properties and Aggregation Behavior of the Potassium Salt of the Highly Unsaturated Diacid Norbixin

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).     

Surface bio-modification of poly(hydroxybutyrate-co-hydroxyhexanoate) and its aging effect

In this work, poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx) film was fabricated by a solution-casting method and subsequently was modified by NaOH treatment to improve the surface hydrophilic property. Surface properties including hydrophilicity, surface appearance and functional groups were characterized by water contact angle measurement, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed the hydrophilicity of PHBHHx film was obviously improved by the NaOH treatment due to the topography changes promoted by the NaOH-etching and the introduction of polar groups included hydroxyl and carboxyl on the topmost surface layers. However, the modified film exhibited an aging effect: the hydrophilicity decreases with time elapsed during storage. It was found that the aging rate was strongly dependent on the crystallinity of the film and the storage environment. The sample with high-crystallinity lost hydrophilic property slower than that with low-crystallinity. Hydrophilic and low-temperature environment also prevented the modified PHBHHx from fast losing of the hydrophilicity.