聚醚砜激基缔合物的荧光光谱研究

本文研究了劳环在主链上的刚性高分子聚醚砜在二氯甲烷溶液中的荧光光谱.结果表明在适当的浓度下它也能形成分子间激基缔合物.     

聚醚砜的磺化及表征

磺化是芳环聚合物改性的有效方法．引入的磺酸基以酸型、盐型和酯型存在,且可以继续制备其它衍生物．有关聚苯醚［１,２］、聚苯硫醚［３］、聚醚醚酮［４,５］和聚砜［６～８］的磺化研究和表征已有很多报道,这些聚合物引入磺酸基后亲水性增强,广泛用于制备反渗透膜...     

溶胶-凝胶法制备聚醚砜-二氧化硅复合材料

以聚醚砜(PES)为基体,通过溶胶-凝胶过程,得到了分散均匀的PES/SiO₂杂化材料,用扫描电镜、透射电镜、傅里叶红外及差示扫描量热法研究不同SiO₂含量的PES/SiO₂杂化材料材料性能.结果表明,当PES/SiO₂杂化材料中SiO₂的质量分数大于10%时可获得有机聚合物链段与无机网络互穿的均匀分散的复合材料.此材料的玻璃化转变温度(Tg)明显提高.     

Evaluation of low-cost disposable polymeric materials for sorptive extraction of organic pollutants in water samples

The capabilities of four commercially available and low cost polymeric materials for the extraction of polar and non-polar contaminants (log K_ow = −0.07–6.88, from caffeine to octocrylene, respectively) from water samples was compared. Tested sorbents were polyethersulphone, polypropylene and Kevlar, compared to polydimethylsiloxane as reference material. Parameters that affect the extraction process such as pH and ionic strength of the sample, extraction time and desorption conditions were thoroughly investigated. A set of experimental partition coefficients (K_pw), at two different experimental conditions, was estimated for the best suited materials and compared with the theoretical octanol–water (K_ow) partition coefficients of the analytes. Polyethersulphone displayed the largest extraction yields for both polar and non-polar analytes, with higher K_pw and lower matrix effects than polydimethylsiloxane and polypropylene. Thus, a sorptive microextraction method, followed by large volume injection (LVI) gas chromatography–tandem mass spectrometry (GC–MS/MS), was proposed using the former sorbent (2 mg) for the simultaneous determination of model compounds in water samples. Good linearity (>0.99) was obtained for most of the analytes, except in the case of 4-nonylphenol (0.9466). Precision (n = 4) at 50 and 500 ng L⁻¹ levels was in the 2–24% and limits of detection (LODs) were in the 0.6–25 ng L⁻¹ range for all the analytes studied.     

聚苯硫醚及其聚醚砜共混物结晶形态的研究

本文借用偏光显微镜(PLM)、扫描电子显微镜(SEM)、小角激光光散射仪(SALS)及蚀刻的方法,研完了聚苯硫醚及其与聚醚砜共混物的结晶形态和织构,讨论了共混方法及其共混组成对其共混物的结晶形态的影响。结果表明,聚苯硫醚在应力作用下能生成横晶;溶液共混物和粉末机械共混物呈现不同的共混结晶形态;随着聚醚砜组分的增加,共混物的织构从聚苯硫醚为连续相逐渐转变为聚醚砜为连续相,同时,聚醚砜的聚集区域从分散在聚苯硫醚的球晶之间转变为聚集在聚苯硫醚的球晶内,使聚苯硫醚的球晶形态逐渐变得不规整。     

紫外光辐照下聚醚砜激基缔合物形成的荧光研究

本文研究了聚醚砜(PES)的二甲基甲酰胺溶液的荧光光谱。发现在通常情况下,浓度在0.0004mg/mL～1mg/mL的范围内,只有聚醚砜的单分子荧光峰。但用波长为280nm的紫外光照射样品溶液能形成激基缔合物,且Ι_e/Ι_m与照射时间有关。     

The influence of phase inversion process modified by chemical reaction on membrane properties and morphology

In this study, the chemical reaction between acetic acid (CH₃COOH) used as non-solvent additive of casting solution and sodium carbonate (Na₂CO₃) dissolved in water as coagulant was employed to modify the classical phase inversion process. By means of this method, the polyethersulphone (PES) ultrafiltration (UF) membranes were prepared. The influence of acetic acid on the properties of the polymer solution was examined by viscometry and related to the morphology of the membrane prepared from the casting solution. The membranes were characterized in terms of the pure water flux, solute transport and field emission scanning electron microscope (FESEM) observation. It was found that chemical reaction between the additive and coagulant increases membrane permeability and mean pore size while maintaining the relatively narrow pore size distribution. FESEM images also confirmed that the chemical reaction contributes to suppress the formation of macrovoid and enhance the interconnectivity of pore. Furthermore, the potential mechanism of membrane formation influenced by chemical reaction was explored tentatively.