荷电膜膜电位及其渗透传质机理研究-应用化学专业论文.docxVIP

中国科学技术大学硕士学位论文Abstract 中国科学技术大学硕士学位论文 Abstract Recent years，transport of species through membranes has been deserved much attention wi廿1 the increasing use and development of membrane science and technology．Among various membrane processes，charged membrane predominate in application scope due to the necessity of antifouling and ionic rejection．Conventional transport mechanism of membrane hasn’t been kept pace with the development of membrane science and technologies in transport process of charged membrane， because the some assumptions ofthe most developed model does not coinced with the situation，e．g．，in most model development，the membrane have been assumed to be a symmetric structure．In fact，in the practical commercial applications，the membrane is often of asymmetrical structure to reduce the transport resistance and enhancement of the intensity of it，i．e．，a charged and dense top layer and a porous，uncharged sublayer In addition，in the transport theory based on percolation theory,it is most dependent on analytical methods used to study the transport mechanism of percolation transport，the result of which is dependence on the results of the experiments of given conditions． As a mal，hematic t001 for percolation theory,the results should be universal because the results of numerical and analytical method don’t depend on the experimental conditions．Therefore，in this job，the special attention will be given to the following two aspects： 1．Dne to the difference in material characteristics．we now assume a non—continuous concentration at the interface．i．e．．the interface concentration at charged layer side will differ from that at the uncharged side due to Donnan exclusion effect．To elucidate the nature at interface of asymmetrical nanofiltration membrane． interfacial concentration at the top layer side was reconsidered by a contact factor． The contact factor was calculated and analyzed by a computer program．Using this contact factor，an asymmetrical membrane potential for