Mechanism of Degradation of Liquid Membranes and Washout Characteristics of the Membrane Liquids

本研究涉及使用液体表面活性剂膜（ELM）和支撑液膜（SLM）的分离技术。[1]研究了乳化液滴对水的夹带作用以及有机溶剂-Span 80体系的液滴破裂。甲苯膜的破裂比高级链烷烃的破裂多10倍。因此，可以得出结论，正十二烷是最适合作为溶剂的ELMs。[2]用穿透时间测试了用各种有机溶剂浸渍的SLM的稳定性;结果表明，具有较高界面张力的溶剂对膜液的洗脱更稳定。从液滴接触角的角度考察了固体载体的材料和形态对SLM稳定性的影响<theta>。在<theta>cos与接触时间的曲线图上，将外推值cos -&gt;1<theta>作为“临界润湿时间”引入，其可以量化聚乙烯的降解。 ...更多信息 SLM。[3]对于<k_c>两种类型的SLM（平板和中空纤维模块），确定了通过SLM装置的流动通道中的液体侧传质系数。对于<k_c>平板型SLM的-值与平板的理论方程吻合得很好，而<k_c>中空纤维的外部是平板的5至10倍大。溶质通过膜液层扩散的传递系数在具有不同孔隙率的支撑聚合物之间没有显著差异。[4]为了在SLM操作中获得更高的回收率，测试了多层平坦型SLM用于从酸溶液中分离Cr（VI）。在反萃液中加入Cr（VI），由于缓冲作用，回收率显著提高。[5]为了延长膜的使用寿命，提出了利用膜液浮力和毛细管作用的膜相再生模式。通过使用单个中空纤维模块，连续再生SLM被证明用于分离重金属，并且还证实了对多纤维模块的适用性。少

Present study is concerned with separation technique using liquid surfactant membranes(ELM) and supported liquid membranes(SLM).[1] The entrainment of water by emulsified dropletes was examined as well as the droplet breakdown for organic solvent-Span 80 systems. The breakdown of toluene membranes is more than those of higher parafinic hydrocarbons by a factor of 10. Thus it can be concluded that n-dodecane is most suitable as the solvent for ELMs.[2] Stabilities of SLMs impregnated with various organic solvents were tested in terms of the breakthrough time; the results show that the solvent having higher interfacial tension is more stable to washing out of the membrane liquids. Effect of materials and morphology of solid supports on the SLM-stability was examined from the contact angle <theta> of aqueous drop on SLMs. An extrapolating value to cos <theta> ->1 on a plot of cos <theta> versus contact time was introduced as a "critical wetting time", which can quantify the degradation of … More SLMs.[3] Liquid side mass transfer coefficient, <k_c> , in the flow channel through a SLM-device was determined for two types of SLM; flat sheet and hollow fiber modules. The <k_c> -values for the flat type SLM agree well with a theoretical equation for flat plate, while the external <k_c> of the hollow fiber was five to ten times as large as those for the flat plate. Transport coefficients for solute diffusion through the membrane liquid layer have no significant difference among the support polymers having various porosity.[4] In order to obtain higher recovery in SLM-operation, a multilayered flat type SLM was tested for the separation of Cr(VI) from the acid solutions. The addition of Cr(VI) to the stripping solution results in a remarkable improvement of the recovery due to the buffer effect.[5] To enlongate the life-time of SLMs, a regeneration mode of the membrane phase in SLMs was proposed, which utilized a buoyant force of membrane liquid and capillary action. The continuous regenerating SLM was demonstrated for the separation of heavy metals by use of a single hollow fiber module, and also the applicability to a multi-fiber module was confirmed. Less