Phase behavior of TXs/toluene/water microemulsion systems for solubilization absorption of toluene

Triton Xs(TXs) surfactants/cosurfactant/water/oil(toluene) microemulsion systems for enhancing toluene solubilization were proposed and its potential was investigated for toluene removal from gas stream.The results indicated that TX-100 was superior to other TXs surfactants in removing toluene without cosurfactant.The efficiency of cosurfactants for improving toluene solubilization capacity follows the order:amine>alcohol>acid.According to the factor analysis,the linear cosurfactants are better than the bra...     

Mini-Review： Green sustainable processes using supercritical fluid carbon dioxide

Environmentally benign carbon dioxide offers significant potential in its supercritical fluid phase to replace current reliance on a range of hazardous,relatively expensive and environmentally damaging organic solvents that are used on an extensive global basis.The unique combination of the physical properties of supercritical fluids are being exploited and further researched to continue the development and establishment of high efficiency,compact plant to provide energy and water efficient manufacturing processes.This mini-review is focused on the use and potential applications of supercritical fluid carbon dioxide for a selected range of key and emerging industrial processes as a sustainable alternative to totally eliminate or greatly reduce the requirement of numerous conventional organic solvents.Examples of the industries include:chemical extraction and purification,synthetic chemical reactions including polymerization and inorganic catalytic processes.Biochemical reactions involving enzymes,particle size engineering,textile dyeing and advanced material manufacture provide further illustrations of vital industrial activities where supercritical fluid technology processes are being implemented or developed.Some aspects relating to the economics of sustainable supercritical fluid carbon dioxide processes are also considered.     

Fast and Living Ring-Opening Polymerization of l-Lactide Initiated with In-situ–Generated Calcium Alkoxides

The ring-opening polymerization of l-lactide with calcium alkoxides generated in-situ from bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] and 2-propanol are presented. The polymerization in THF at room temperature proceeds rapidly and in a living manner, giving poly(l-lactide)s of controlled molecular weight, low polydispersity, and tailored end-functionalities. Kinetic studies show the absence of an induction period and a pseudo-first order rate constant of 6.41 L mol^–1 min^–1, which is significantly higher than for related Y₅(-O)(O ⁱ Pr)_13– or aluminum alkoxide-initiated polymerizations. The initiation involves a two-step process: (1) alcoholysis of bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] to give the corresponding calcium alkoxide and (2) ring-opening of l-lactide via acyl-oxygen cleavage and insertion into the calcium-alkoxide bond. In the presence of excess alcohol, fast and reversible exchange between free alcohol molecules and coordinated alkoxide ligands takes place. This allows tuning of the poly(l-lactide) molecular weight over a wide range.     

Species analysis methods for hydrolysis polymerization of aluminum

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反相微乳液聚合PAM在悬浮介质中的絮凝过程研究

研究了Span80-Tween80/异辛烷/H2O反相微乳液聚合丙烯酰胺反相微乳液聚合所得到的PAM的微观结构及其在1%高岭土悬浮液的模拟废水中的絮凝过程与机理。采用电子显微镜、激光纳米粒度仪、分光光度计等测试手段,测定了PAM粒子以及与悬浮介质结合的絮体形态、粒径和粒径分布等微观结构及其絮凝性能。试验结果表明:反相微乳液聚合所制备的PAM为单分散、球形的纳米材料,粒径(D)在145～175nm之间;AMPS改性PAM与高岭土结合后,高岭土与高分子团状结构包埋在一起,透过率较大,絮凝范围宽,可以理解为高分子絮凝剂的"架桥-吸附-网捕"机理。     

膜表面光接枝改性的研究现状及展望

本文介绍了利用紫外光将单体接枝到聚合物表面的技术原理与条件 ,并介绍了分离膜表面进行光接枝聚合的研究进展及发展趋势     

聚丙烯酸酯反相破乳剂制备条件优化及性能评价

以甲基丙烯酸(MAA)和丙烯酸乙酯(EA)为原料,通过乳液聚合制备了聚丙烯酸酯类反相破乳剂P(EA-MAA)。通过单因素实验考察了各因素对产物分子量、乳液粒径中值、聚合物凝胶残渣以及产物除油性能的影响,实验结果表明：在单体总质量分数为10%、单体配比(EA﹕MAA)为1:1,单体加入顺序为先EA后MAA,反应温度70℃,引发剂用量为1‰(占单体总质量分数),反应时间为6h的条件下,制备的P(EA-MAA)分子量大,粒径中值小,聚合物凝胶残渣少,除油率达到94.7%。     

PDA的制备及其对水体中邻苯二甲酸二甲酯的去除性能

以二甲基二烯丙基氯化铵(DMDAAC)和丙烯酰胺(AM)为原料,Span-80和Tween-80为乳化剂,液体石蜡为分散相,采用分批加料法,反相乳液聚合制备二甲基二烯丙基氯化铵与丙烯酰胺的共聚物(PDA)。研究内容包括单体配比、引发剂配比、油水体积比和pH值对产物特性粘度的影响。研究获得的优化聚合条件为:单体质量比(DMDAAC∶AM)为2∶8,引发剂质量比(NaHSO3∶K2S2O8)为5∶3,油水体积比为1∶1.2,pH值为8。选用自制PDA用于去除水中邻苯二甲酸二甲酯(DMP)时,在絮凝剂PDA的投加量为0.60 mg/L,pH值为10时,DMP的去除效果最好,去除率达到98.31%。     

PA/蒽醌/PVDF复合纳滤膜结构与性能及其应用

以聚偏二氟乙烯(PVDF)超滤膜为基膜,采用聚乙烯亚胺(PEI)与单宁酸(TA)和没食子酸(GA)的混合物共沉积后,再与均苯三甲酰氯(TMC)进行界面聚合的方法制备了PVDF复合纳滤膜,探讨了TA与GA的混合质量比例对PVDF复合纳滤膜选择层的微观结构和性能的影响,分别采用FTIR、AFM、SEM和水接触角测量仪对复合纳滤膜选择层的化学结构、表面粗糙度、微观结构和表面亲水性进行了表征,考察了PVDF复合纳滤膜在模拟RB5-NaCl染料废水处理中的性能和稳定性。结果表明：随着TA:GA比例的增加,选择层的表面粗糙度增加、水接触角减小,纯水通量增加,PEG1000截留率略有降低;染料废水通量和截留率呈相同的变化趋势,染料和盐的分离因子达到12.97;PVDF复合纳滤膜在运行时间内表现出良好的稳定性。     

微乳法制备W/O型Fe3O4磁流体及其清除水面浮油模拟研究

应用复合乳化剂和助表面活性剂制备出稳定的油包水(W／O)型微乳液,利用拟三元相图和体系电导随组成的变化,探明了一定条件下形成W／O型微乳液的最佳体系,进而利用W／O型微乳液作为“微反应器”合成Fe2O4磁流体,应用TEM对制备的磁流体进行了表征．初步模拟了用磁流体清除水面浮油的实验,获得令人满意的结果。