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《Analytical letters》2012,45(12):2355-2366
Abstract An indirect atomic absorption spectro-metric (AAS) method using electrothermal atomization (ETAAS) for the determination of cationic surfactants has been proposed. The method involves ion-pair formation between cationic surfactant and sodium hexanitro-cobaltate(III), extraction of the ion-pair into 1, 2-dichloroethane and determination of cobalt con centration in organic phase by ETAAS and hence indirectly relating to the cationic surfactant concentrations. Surfactants of the anionic and nonionic group do not interfere to a great extent, and matrix inter ferences from many other cations, anions and organics are also not observed. The method has been success fully applied to cationic surfactant determination in waste water and hair rinsers. Relative standard deviation values (RSD) of 3.2% for waste water samples and 4.3% for shampoo were observed in these analyses. 相似文献
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乳化剂对阳离子乳液聚合及乳胶粒性能的影响 总被引:1,自引:0,他引:1
以苯乙烯、丙烯酸丁酯为非离子单体,甲基丙烯酰氧乙基三甲基氯化铵(DMC)为阳离子单体,偶氮二异丁基脒盐酸盐(AIBA)为引发剂,十六烷基三甲基氯化铵(CTAC)和乙撑基双(十六烷基二甲基氯化铵)(G16—2—16)为乳化剂,采用半连续种子乳液聚合法进行阳离子乳液聚合。探讨了乳化剂的分子结构和用量对反应速率、单体转化率以及乳胶粒粒径、Zeta电位等的影响。结果表明:乳化剂的用量越大,反应速率越大,单体转化率越高,而乳胶粒粒径越小;使用G16—2—16作乳化剂时,单体转化率较高,乳胶粒粒径较大,Zeta电位较高。 相似文献
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金属-有机骨架材料用于废水处理 总被引:1,自引:0,他引:1
废水中的各种有害物质常常具有生物毒性或致癌性,因此如何高效、节能地处理水体污染是一个亟待解决的重要问题。金属-有机骨架材料(metal-organic frameworks, MOFs)是一种新型纳米多孔材料,具有种类多样性、结构可设计性与可调控性、高比表面积及良好的热稳定性等优点,已成为当前化学、材料学科的一个研究热点, 在多个领域显示出潜在的应用前景,尤其是在分离方面。与气相分离相比,MOFs用于液相分离的研究较少。本文综述了近年来MOFs用于含有染料、药物、醇、芳香族化合物、重金属离子及其他离子的废水处理的研究进展,重点剖析了MOFs的孔结构、骨架电荷及功能性对分离效果的影响,并结合本课题组的研究工作,对这种新型多功能材料在水处理方面的前景和今后的研究重点作了展望。 相似文献
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利用电纺丝技术制备了聚丙烯腈纳米纤维无纺布, 然后在水溶液原位偕胺肟化得到偕胺肟化聚丙烯腈纳米纤维, 该纳米纤维可用于吸附再生含金属离子废水. 采用氯化铜溶液模拟含金属离子废水, 探讨不同肟化率的偕胺肟化纳米纤维对铜离子的吸附效果; 发现肟化率78.8%的偕胺肟化纳米纤维的吸附能力最好, 利用Langmuir吸附方程得到最大吸附值为56.5 mg/g, 同时吸附后可将含铜废水浓度从100 mg/L降至13 μg/L, 远远低于国标GB8978-1996规定的铜排放的一级标准(总铜浓度<0.5 mg/L). 吸附铜离子的纳米纤维在1 mol/L稀硝酸中, 100 min后铜离子的解吸附率超过98%. 经4次吸附-解吸附循环后, 偕胺肟化纳米纤维的吸附能力仍能达到首次吸附最大吸附值的50%以上, 表明偕胺肟化纳米纤维具有一定的循环再生能力. 相似文献
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Cationic fluorinated polyacrylate soap-free latex (CFMBD) was synthesized by semi-continuous seeded emulsion polymerization of dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and dimethylaminoethyl methacrylate (DM) with a novel cationic polymerizable emulsifier, maleic acid double ester-octadecyl poly(ethyleneoxy)20 ether-ethylene trimethyl ammonium chloride (R303), and 2,2′- azobis (2 - methylpropionamidine) dihydrochloride (VA-50) was utilized as the initiator. Effects of some factors, such as VA-50 amount, R303 amount and DFMA amount, on stability and average particle size of the CFMBD were discussed in detail, and the optimal polymerization condition was obtained. In addition, the emulsion and its film were characterized by Fourier transform infrared (FTIR) spectrometry, thermogravimetry analysis (TGA), contact angle goniometer, X-ray photoelectron spectroscopy (XPS), respectively. FTIR confirmed the structure of the CFMBD. With the increasing of DFMA amount, water absorption of the film decreased and water contact angle of the film increased. While the DFMA amount was more than 6 g in the recipe, the water contact angle (107.5°) and the water absorption (7.8 wt%) of the film showed no more changes. Meanwhile, thermal stability of the copolymer was greatly improved with the increasing of DFMA amount. XPS analysis indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface. 相似文献
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硅氧烷乳液聚合过程中大颗粒形成机理研究:Ⅰ.阳离子型乳液的耐电解质… 总被引:5,自引:1,他引:5
探讨了二甲基聚硅氧烷阳离子型乳液耐电解质稳定性的影响因素。结果表明,加入少量的非离子型表面活性剂与阳离子型乳化剂并用进行乳液聚合,可以保护乳液粒子,防止由于电解质引的乳液粒子的相互凝聚而形成大颗粒。 相似文献
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pH响应性阳离子型微凝胶的制备及性质研究 总被引:1,自引:0,他引:1
以甲基丙烯酸-(N,N-二甲氨基)乙酯(DMAEMA)和丙烯酸乙酯(EA)为共聚单体, 二甲基丙烯酸乙二醇酯(EGDMA)为交联剂, 采用半连续乳液聚合法, 制备了具有pH响应性的阳离子型微凝胶, 并研究不同聚合条件对所合成的微凝胶性质的影响. 利用透射电子显微镜(TEM)、激光粒度分析仪和流变仪对微凝胶进行一系列表征. 研究了介质pH值对微凝胶的形态、平均粒径、zeta电位、溶液浊度(透光率)的影响, 以及NaCl盐溶液对微凝胶分散体系稳定性的影响. 结果表明, 这类阳离子型微凝胶体系具有良好的pH响应性, 在pH=7左右发生相转变. 此外, 研究表明不同浓度NaCl溶液对微凝胶的稳定性有一定影响, 临界絮凝浓度约为1.3 mol8226;L-1. 相似文献
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Cristiane Costa Verusca H. S. Santos Claudia Sayer Pedro H. H. Araujo Alexandre F. Santos Montserrat Fortuny 《Macromolecular Symposia》2011,302(1):161-168
Summary: Emulsion polymerization reactions were performed under microwave irradiation and conventional heating using anionic or cationic initiators and surfactants. Microwave irradiation promoted higher reaction rates for both initiators and surfactants, in comparison with the conventional heating. The effect of high power microwave irradiation was studied using a method of cycles of heating and cooling, where rapid polymerization reactions were obtained. In the reactions with anionic initiator and surfactant, a decrease in the particle diameters was observed with microwave heating, and even smaller particles were obtained using high power microwave irradiation. Moreover, the decrease in the particle size was acompanied by an increase in the polymer molecular weight. On the other hand, these effects were not observed for reactions with cationic initiator and surfactant. 相似文献
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高分子阳离子絮凝剂用于炼油废水处理研究 总被引:15,自引:0,他引:15
用聚二甲基二烯丙基氯化铵型高分子阳离子絮凝剂处理炼油废水考察了险油和化学耗氧量的动态变化规律。对产生的浮渣性质及滤饼的成份进行了研究。并且与聚合铝的处理效果进行对照。研究结果表明,HCA除油和化学耗管氧量的性能优于PAC,HCA产生的浮渣是PAC的三分之一,而浮渣中的含油量则是PAC的三倍。 相似文献