Force measurement between mica surfaces in electrolyte solutions  

电解质溶液中云母间表面力的测量(英文)

作　　者：赵古田[1] 郭纬川[1] 谭启檐[1] 裘英华[1] 阚亚鲸[1] 陈云飞[1,2] 倪中华[1] 

机构地区：[1]东南大学江苏省微纳生物医疗器械设计与制造重点实验室,南京211189 [2]东南大学MEMS教育部重点实验室,南京210096

出　　处：《Journal of Southeast University(English Edition)》2013年第1期57-61,共5页东南大学学报（英文版）

基　　金：The National Basic Research Program of China(973 Program)(No.2011CB707605);the National Natural Science Foundation of China(No.50925519,50821063)

摘　　要：The forces between two molecularly smooth mica surfaces are measured in monovalent and divalent cations electrolyte solutions by a surface force apparatus （SFA）. The properties of K＋, Na＋, and Mg2＋ between molecularly smooth mica surfaces are investigated. The Derjagui-Landau- Verwey-Overbeek （DLVO） force and the hydration force are detected in the experiment. The results show that in lower concentrations of a monovalent electrolyte solution （about 10-4 mol/L）, the force curves are completely in good agreement with those computed by the DLVO theory. However, additional short-range repulsive forces which deviate from the DLVO theory are observed when the concentrations of cations are above the critical bulk concentration, which is different for each electrolyte. The results show the properties of these cations on both the screening effect adsorbed on the mica surface and the hydration in solution. From the results, the interaction energy between two hydrated ions of potassium or sodium can also be estimated.利用表面力仪(SFA)测量一价与二价电解质溶液中分子级光滑的云母表面间作用力.研究了钾离子、钠离子、镁离子在分子级光滑表面云母间的性质.实验中测量了DLVO作用力及水合力,结果表明:在较低浓度的一价离子溶液(约10-4mol/L)中,实验中所测得的力与DVLO理论力曲线完全一致.然而在浓度超过反离子临界浓度时,额外的短程斥力偏离DLVO理论值,临界浓度对于每一种离子是不同的.实验结果展现了这3种离子对云母表面的屏蔽效应差异及在溶液中的水合性质.此外,从这些结果可以评估2个水合钠离子或者2个水合钾离子之间的作用能.

关 键 词：surface force apparatus （SFA） DLVO force hydration force screening effect 

分 类 号：O561.4[理学—原子与分子物理]