PS-PBA粒子分散系的介电弛豫谱解析——同、反离子对弛豫的影响及表界面电参数的计算  

Analysis of dielectric relaxation spectroscopy for the PS-PBA particle suspension——Influence of co-and counter-ion on relaxation behavior and computations of interfacial electrokinetic parameters

作　　者：赵孔双[1] 聂梦云[1] 王华瑞[1] 李娇阳[1] 

机构地区：[1]北京师范大学化学学院,北京100875

出　　处：《中国科学：化学》2010年第8期1046-1055,共10页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(20673014&20976015)资助

摘　　要：制备了近纳米级的聚苯乙烯-丙烯酸丁酯(PS-PBA)复合微球粒子,并在40Hz～110×106Hz的宽频范围测量了该粒子分散在9种电解质中时的介电弛豫谱,发现了与PS微球粒子分散系不同的特异介电弛豫:低频弛豫对反离子种类具有敏感性而高频弛豫则与电解质种类几乎无关;根据Shilov-Dukhin模型和M-W-O模型分别分析了高、低频率的弛豫机制,并通过对介电谱的Cole-Cole拟合获得了各体系的介电参数.进一步利用Hanai方法由介电参数计算获得了所有体系的相参数;详细分析了体系的内部参数受PS-PBA微球自身结构以及电解质种类影响的原因;讨论了离子扩散系数对介电参数的影响,从而得出了低、高频的弛豫特征时间分别由同离子的扩散系数和反离子的扩散系数所决定之结论.最后,结合Grosse宽频介电理论计算了粒子表面的以及双电层的主要电参数,并分析了电解质种类差异对这些电参数的影响.Near-nanoscale polystyrene-poly（butyl acrylate） （PS-PBA） particles were prepared,and the dielectric measurements were carried out for the systems composed of the particles and nine kinds of electrolyte solutions over the 40 Hz–110 MHz range. The special dielectric relaxation phenomenon which are different from PS particle system were observed：The low-frequency relaxation is exceptionally sensitive to ion species and the high-frequency relaxation is independent of electrolyte species. The dielectric parameters were obtained with Cole-Cole equation by fitting experimental data and the phase parameters were calculated by Hanai methods. The Shilov-Dukhin model and the M-W-O model were used to explain the mechanism of the low-frequency and the high-frequency relaxation,respectively. Combining with the configuration of PS-PBA particle reasonable explication about dielectric and phase parameters was given. The influence of ion diffusions indicates that low and high-frequency relaxations were determined by co-ion diffusion coefficient and diffusion coefficient of counterions,respectively. In light of the Gross board frequency dielectric theory,the electrokinetic parameters of particle surface and double layer were calculated and the influence of electrolyte difference toward electro kinetic parameters was analyzed.

关 键 词：PS-PBA微球 介电弛豫谱 离子扩散系数 双电层 动电参数 

分 类 号：O631.3[理学—高分子化学]