Photo-Fenton removal of water-soluble polymers

This paper presents the results of experiments carried out in a laboratory-scale photochemical reactor on the photodegradation of different polymers in aqueous solutions by the photo-Fenton process. Solutions of three polymers, polyethyleneglicol (PEG), polyacrylamide (PAM), and polyvinylpyrrolidone (PVP), were tested under different conditions. The reaction progress was evaluated by sampling and analyzing the total organic carbon concentration in solution (TOC) along the reaction time. The behavior of the different polymers is discussed, based on the evolution of the TOC–time curves. Under specific reaction conditions, the formation and coalescence of solid particles was visually observed. Solids formation occurred simultaneously to a sharp decrease in the TOC of the liquid phase. This may be favorable for the treatment of industrial wastewater containing polymers, since the photodegradation process can be coupled with solid separation systems, which may reduce the treatment cost.     

混酸PEG酯的合成及性能研究

用从大豆油脚水解制得的脂肪酸合成混酸聚乙二醇酯，通过测定酸值的方法确定了最佳反应时间为16h。与油酸聚乙二醇酯相比，混酸聚乙二醇酯具有更优良的乳化性、润湿性，可以替代油酸聚乙二醇酯用于纺织、农药和化妆品工业中。     

酸催化二甘醇脱水环化反应研究

以硫酸、磷钨酸、ZRP-5分子筛为催化剂,研究了二甘醇(DEG)脱水环化的反应规律。结果表明,DEG发生分子内脱水环化反应,生成1,4-二氧六环(DOX),DEG分子间脱水不仅可以生成四甘醇、六甘醇等,同时可生成三甘醇、五甘醇等一系列的多甘醇(PEG)。不仅DEG可以脱水环化生成DOX,在反应中生成的PEG也同样可以进行生成DOX的反应。对于二甘醇(DEG)脱水环化反应,硫酸是性能优良的催化剂,反应可以在较低的温度下进行,馏出产物中DOX选择性大于95％。     

Synthesis and applications of heterobifunctional poly(ethylene oxide) oligomers

Poly(ethylene oxide) (PEO) oligomers are employed extensively in pharmaceutical and biomedical arenas mainly due to their excellent physical and biological properties, including solubility in water and organic solvents, lack of toxicity, and absence of immunogenicity. PEO can be chemically modified and reacted with, or adsorbed onto, other molecules and surfaces. Sophisticated applications for PEO have increased the demand for PEO oligomers with tailored functionalities, and heterobifunctional PEOs are often needed. This review discusses the synthesis and applications of heterobifunctional PEO oligomers possessing amine, carboxylate, thiol, and maleimide functional groups.     

No Direct Postconditioning Effect of Poloxamer 188 on Mitochondrial Function after Ischemia Reperfusion Injury in Rat Isolated Hearts

Myocardial infarction is a leading cause for morbidity and mortality worldwide. The only viable treatment for the ischemic insult is timely reperfusion, which further exacerbates myocardial injury. Maintaining mitochondrial function is crucial in preserving cardiomyocyte function in ischemia reperfusion (IR) injury. Poloxamer (P) 188 has been shown to improve cardiac IR injury by improving cellular and mitochondrial function. The aim of this study was to show if P188 postconditioning has direct protective effects on mitochondrial function in the heart. Langendorff prepared rat hearts were subjected to IR injury ex-vivo and reperfused for 10 min with 1 mM P188 vs. vehicle. Cardiac mitochondria were isolated with 1 mM P188 vs. 1 mM polyethylene glycol (PEG) vs. vehicle by differential centrifugation. Mitochondrial function was assessed by adenosine triphosphate synthesis, oxygen consumption, and calcium retention capacity. Mitochondrial function decreased significantly after ischemia and showed mild improvement with reperfusion. P188 did not improve mitochondrial function in the ex-vivo heart, and neither further P188 nor PEG induced direct mitochondrial protection after IR injury in this model.     

Cycling of lithium/metal oxide cells using composite electrolytes containing fumed silicas

The effect on cycle capacity is reported of cathode material (metal oxide, carbon, and current collector) in lithium/metal oxide cells cycled with fumed silica-based composite electrolytes. Three types of electrolytes are compared: filler-free electrolyte consisting of methyl-terminated poly(ethylene glycol) oligomer (PEGdm, M_w=250)+lithium bis(trifluromethylsufonyl)imide (LiTFSI) (Li:O=1:20), and two composite systems of the above baseline liquid electrolyte containing 10-wt% A200 (hydrophilic fumed silica) or R805 (hydrophobic fumed silica with octyl surface group). The composite electrolytes are solid-like gels. Three cathode active materials (LiCoO₂, V₆O₁₃, and Li_xMnO₂), four conducting carbons (graphite Timrex® SFG 15, SFG 44, carbon black Vulcan XC72R, and Ketjenblack EC-600JD), and three current collector materials (Al, Ni, and carbon fiber) were studied. Cells with composite electrolytes show higher capacity, reduced capacity fade, and less cell polarization than those with filler-free electrolyte. Among the three active materials studied, V₆O₁₃ cathodes deliver the highest capacity and Li_xMnO₂ cathodes render the best capacity retention. Discharge capacity of Li/LiCoO₂ cells is affected greatly by cathode carbon type, and the capacity decreases in the order of Ketjenblack>SFG 15>SFG 44>Vulcan. Current collector material also plays a significant role in cell cycling performance. Lithium/vanadium oxide (V₆O₁₃) cells deliver increased capacity using Ni foil and carbon fiber current collectors in comparison to an Al foil current collector.     

Sol-Gel法制备氧化铝负载铜基超细粒子影响因素的研究

通过对Sol-Gel法制备氧化铝负载铜基超细粒子的研究，表明PEG分散剂对粒度分布有重要影响；采用XRD对制得的催化剂表面组成进行了研究，指出了发生固相反应生成活性较低的CuAl2O4的影响因素。     

Application of enzymatically gelled chitosan solutions to water‐resistant adhesives

An investigation was undertaken on the application of dilute chitosan solutions gelled by tyrosinase‐catalyzed reaction with 3,4‐dihydroxyphenethylamine (dopamine). The tyrosinase‐catalyzed reaction with dopamine conferred water‐resistant adhesive properties to the semidilute chitosan solutions. The viscosity of the chitosan solutions increased highly by the tyrosinase‐catalyzed reaction and the subsequent reactions between o‐quinone compounds and chitosan. These highly viscous, gel‐like modified chitosan materials were allowed to spread onto the surfaces of the glass slides, which were tightly lapped together and held them in water. Tensile shear adhesive strength of over 400 kPa was observed for the modified chitosan samples. The increase in the amino group concentration of the chitosan solutions and the molecular mass of the chitosan used effectively led to the increase in adhesive strength of the glass slides. In addition, in the case where the chitosan solution was gelled by the enzymatic reaction with dopamine in the presence of poly(ethylene glycol), adhesive strength sharply increased at shorter reaction times concomitantly with the increase in the viscosity of the chitosan solutions because the tyrosinase activity effectively was retained by poly(ethylene glycol). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1818–1827, 2007     

丙烯酸聚乙二醇单酯的合成研究

以聚乙二醇-200与丙烯酸直接缩合反应,在不加有毒带水剂的条件下合成了丙烯酸聚乙二醇单酯。探讨影响缩合反应酯化率的因素,确定酯化反应的最佳条件：丙烯酸与PEG200的摩尔比为1.2∶1.0,反应温度是110-140℃,阻聚剂对苯二酚为0.6%（以醇酸总质量计）,反应时间为6 h,催化剂对甲苯磺酸为1.0%（以醇酸总质量计）,产率达89.4%。     

聚乙二醇重氮树脂在聚乙烯膜材料表面的自组装及亲水改性

用铬酸氧化法在聚乙烯薄膜的表面引入了羧基阴离子,合成了端基阳离子性的聚乙二醇重氮树脂,用静电自组装并辅以紫外光照射的方法,在聚乙烯薄膜的表面引入了共价键连接的聚乙二醇分子链.用紫外-可见分光光度法研究了重氮树脂及其静电自组装体系的光分解性质,得到重氮基团的分解速率常数kd=0.021 4 s-1.红外分析表明,紫外光照射后聚乙烯薄膜表面连接的聚乙二醇分子链可耐DMF-ZnC l2-H2O三元极性溶剂的刻蚀.由于在聚乙烯薄膜的表面引入了亲水性的聚乙二醇分子链,其表面接触角从改性前的104°降至48°.