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用超网链(HNC)近似法研究了离子间势能对唐南平衡的影响,并计算了唐南平衡中的平衡密度,渗透压和唐南电位,计算表明,唐南电位比渗透压对离子间热能更灵敏,使用平均离子活度系数,所得唐南电位很接近于以前的研究,使用原正确的单离子活度系数,所得唐南电位更接近实验值。 相似文献
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槲皮素金属配位印迹聚合物膜的制备及性能研究 总被引:1,自引:0,他引:1
以中药活性成分黄酮类化合物槲皮素与Zn(II)的配合物为模板, 以4-乙烯基吡啶为功能单体, 乙二醇二甲基丙烯酸酯为交联剂, 水溶性线性聚合物聚乙二醇(PEG, Mw=600)为添加剂, 利用分子印迹技术紫外光引发原位聚合的方法制备了带支撑的锌离子配位分子印迹聚合物膜. 使用扫描电镜测定了不同PEG用量下膜的表面形貌. 通过膜渗透实验考察了PEG含量对金属配位印迹膜渗透速率的影响, 系列印迹聚合物膜的识别体系及对不同底物的渗透选择性, 同时考察了阳离子和阴离子对印迹膜渗透模板分子的影响. 实验结果表明: 制膜过程中水溶性线性聚合物PEG的加入可以明显改善膜的透过性能|槲皮素-Zn(II)模板印迹聚合物膜对槲皮素表现出明显的渗透选择性, 对槲皮素结构类似物芦丁和柚皮素的渗透选择性较差|且该金属配位印迹聚合物膜对不同阳离子和阴离子也都表现出较好的选择识别作用. 相似文献
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用于渗透气化法分离水—乙醇混合物的含离子膜 总被引:2,自引:0,他引:2
合成了乙烯醇和顺丁烯二酸的交替共聚物,并制成膜,使其与BaCl_2,CaCl_2,SrCl_2及CuSO_4的水溶液反应。将反应产物—含离子聚合物膜用于渗透气化法分离乙醇-水混合物。结果表明,离子膜在渗透速率及分离系数两方面均好于纯聚合物膜。在以上四种离子膜中,含Ba~(2 )离子膜的性能最好,这表明Ba~(2 )离子不仅使膜更加亲水,增加了对水的溶解度,而且由于Ba~(2 )离子引起聚合物分子链间的交联,而使膜变得更加致密,从而提高了膜的分离系数。 相似文献
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铜离子印迹聚合物膜的制备及其渗透性能 总被引:3,自引:0,他引:3
采用分子印迹技术紫外光引发聚合方法制备了带支撑膜的铜离子印迹聚合膜.用扫描电子显微镜观察了膜的表面形态.膜渗透实验结果表明,通过对不同阳离子(如锌离子、钙离子等)的比较,此印迹膜对铜离子有较好的选择渗透性.分别考察了不同支撑膜、致孔剂和功能单体对膜结构及其渗透性能的影响,考察了pH值、阴离子及阳离子对膜渗透性能的的影响.结果表明,采用PVDF膜为支撑膜,乙酸铜为印迹离子合成的铜离子印迹膜,在pH值为1左右,阴离子为乙酸根离子时,对铜离子有较好的选择渗透性. 相似文献
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Hofmeister离子序列涉及到的问题十分广泛,对很多化学和生物体系都有影响。关于Hofmeister离子序列调控水溶液中大分子溶质行为的作用机制,目前的研究主要有两类观点:一类认为Hofmeister离子是通过与水分子相互作用间接影响水溶液中大分子溶质的存在状态及聚集行为;而另一类则认为Hofmeister离子与水溶液中大分子溶质之间存在直接相互作用是导致Hofmeister离子序列的内在原因。本文详细介绍了上述两类观点的研究工作,并对该领域的最新进展进行了评述。由于实际体系中可能存在水分子-水分子、水分子-离子、水分子-溶质分子、阴离子-阳离子等众多复杂的相互作用,上述两类观点其实都只是从一个侧面解释了Hofmeister离子序列,对Hofmeister离子序列及其作用机制的研究仍然有待深入。 相似文献
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以1-乙烯基-3-乙酸乙酯咪唑氯离子液体为功能单体,以再生纤维素膜为基膜,采用温和的表面ATRP接枝聚合技术在水溶液中制备了溶菌酶分子印迹膜.通过紫外-可见光谱分析了离子液体与模板分子的作用力,讨论了功能单体1-乙烯基-3-乙酸乙酯咪唑氯用量对印迹复合膜性能的影响,研究了分子印迹复合膜对溶菌酶模板分子及其结构类似物的吸附行为和选择性识别特性.结果表明,以1-乙烯基-3-乙酸乙酯咪唑氯离子液体作为功能单体的溶菌酶分子印迹膜能够从结构类似物混合体系中选择性分离富集溶菌酶,且具有很好的稳定性和可再生性能. 相似文献
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荷电膜的膜电位研究进展 总被引:1,自引:0,他引:1
膜电位的测定是表征荷电膜的传递现象的重要参数之一。本文简要介绍了膜电位理论基础,包括T. M. S.理论和不可逆热力学理论。分别阐述了关于离子交换膜、双极膜、两性膜以及复合膜的膜电位的最新进展,并提出今后的发展方向。 相似文献
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Zeolite X membranes were investigated by in-situ hydrothermal synthesis on porous ceramic tubes precoated with zeolite X seeds or precursor amorphous aluminosilicate, and porous α-Al2O3 ceramic tubes with a pore size of 50 200 nm were employed as supports. Zeolite X crystals were synthesized by the classic method and mixed into deionized water as a slurry with a concentration of 0.2 0.5wt%, having a range of crystal sizes from 0.2 to 2μm. Crystal seeds were pressed into the pores near the inner surface of the ceramic tubes, and crystallization took place at 95℃ for 24-96 h. It was also investigated that Boehmite sol added with zeolite X seeds was precoated on ceramic supports to form a layer of γ-Al2O3 by heating, and hydrothermal crystallization could then take place to prepare the zeolite membranes on the composite ceramic tubes. The crystal species were characterized by XRD, and the morphology of the supports subjected to crystallization was characterized by SEM. The composite zeolite membranes have zeolitic top-layers with a thickness of 10-25 μm, and zeolite crystals can be intruded into pores of the supports as deeply as 100μm. The experimental results indicate that the precoating of zeolitic seeds on supports is beneficial to crystallization by shortening the synthesis time and improving the membrane strength. The resulting zeolite X membrane shows permselectivity to tri-n-butylamine((C4H9)3N) over perfluro-tributyl-amine ((C4Fg)3N), and a permeance ratio of 57 for ((C4Hg)3N to (C4F9)3N could be reached at 350℃. Permeances of BZ, EB and TIPB through the zeolite membrane were also measured and were found to slightly increase with temperature. 相似文献
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PREPARATIONOFSILICALITE┐1ANDZSM┐5ZEOLITE/CERAMICCOMPOSITEMEMBRANESZhangLixiong,JiaMengdong,MinEnze(ResearchInstituteofPetrole... 相似文献
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Zhongqiang Xu Qingling Chen Guanzhong LuShanghai Research Institute of Petrochemical Technology Shanghai ChinaInstitute of Industrial Catalysis East China University of Science Technology Shanghai China 《天然气化学杂志》2002,(Z2)
Zeolite X membranes were investigated by in-situ hydrothermal synthesis on porous ceramic tubes precoated with zeolite X seeds or precursor amorphous aluminosilicate, and porous α-Al2O3 ceramic tubes with a pore size of 50-200 nm were employed as supports. Zeolite X crystals were synthesized by the classic method and mixed into deionized water as a slurry with a concentration of 0.2-0.5wt%, having a range of crystal sizes from 0.2 to 2μm. Crystal seeds were pressed into the pores near the inner surface of the ceramic tubes, and crystallization took place at 95℃ for 24-96 h. It was also investigated that Boehmite sol added with zeolite X seeds was precoated on ceramic supports to form a layer of r-Al2O3 by heating, and hydrothermal crystallization could then take place to prepare the zeolite membranes on the composite ceramic tubes. The crystal species were characterized by XRD, and the morphology of the supports subjected to crystallization was characterized by SEM. The composite zeolite membranes hav 相似文献
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A model of the composite membrane consisting of the catalytic layer (CL) and the nanofiltration layer (NFL) is presented. It has been found that applying NFL on the permeate side of CL it is possible to enhance substantially the conversion of substrate into the product. The best performance is obtained for high retention of substrate and low of product. At higher values of volume flow and/or longer catalytic path the retention degree of product becomes negligible. The presence of NFL enhances the influence of distribution of the reaction rate constant, k, on the conversion ratio. Comparing to k = constant the positive effect is obtained if k increases along the catalytic pore, whereas negative—if k decreases. 相似文献