Surface Chemical Studies of Dispersion and Coagulation of Colloid Particles

胶体粒子的稳定性一直是胶体和表面科学研究的重要课题之一。由于胶体体系在包括医学应用在内的现代高科技中的应用，人们对胶体体系稳定性的兴趣迅速增加。这次合作研究由18名成员组成，他们在不同的领域进行自己的研究，但与一个共同的学科-胶体稳定性有关。这项研究包括两个项目：1)从一个原始批次分配给每个成员的聚苯乙烯胶乳粒子临界凝聚浓度CCC的合作测量；2)各自对象的单独研究。研究结果表明，在硝酸盐存在下，带负电乳胶包膜的Cc值K^1为2 30 mm(标准差=52 mm)，Mg^lt；2+&gt；为18.9 mm(=5.6 mm)，La^&lt；3+&gt；为0.47 mm(=0.048 mm)。The Ratio…除二价镁离子显示出较大的值外，大多数CCC为100：8.2：0.20，与DLVO理论所预测的比例100：1.6：0.15符合得相当好。应用DLVO理论，用CCC和Zeta电位估算了乳胶粒在水介质中的Hamaker常数。测得胶乳在水介质中的Hamaker常数平均值为1.52x10^&lt；-20&gt；J，介于胶体稳定性实验得到的Hamaker常数(0.1-11×10^&lt；-20&gt；J)的文献值之间，但比Lifshitz理论测得的0.35×10^-20&gt；J大4倍。K&lt；@d1+@&gt；d1、mg&lt；@d12+@&gt；D和La&lt；@d13+@&gt；d1的ccc值分别为2 0 5 mm(=11 mm)、18.8 mm(=0.80 mm)和0.5 1 mm(=0.034 mm)。Hamaker常数的平均值为1.07×10~(-1)~(？)d1~(-20)，第二个散射量小得多的结果正好与第一个结果相符。个别研究的结果请参阅所附的出版物清单。较少

The stability of colloid particles has been one of the most important subjects in colloid and surface science. The interest in stability properties colloidal system has been increasing rapidly due to their utility in modern high-technology including medical application.This cooperative study consists of 18 members who are conducting their own research in a variety of field but are connected with a common subject, i.e., colloid stability. The study consists of two projects; 1) cooperative measurements of critical coagulation concentration, CCC, of polystyrene latex particles which were distributed to each member from one original lot and 2) individual research of their own subjects. Results of the coolerative research are summarized as follows.Mean values of CCC's of negatively charged latex perticles were found to be 230 mM (standard deviation, =52 mM) for K^1, 18.9 mM( = 5.6 mM) for Mg^<2+>, and 0.47 mM( =0.048 mM) for La^<3+>, respectively, in which nitrate salts were used. The ratio … More of these CCC's is 100:8.2:0.20, in fairly good agreement with the ratio predicated by the DLVO theory, i.e., 100:1.6:0.15, except for divalent Mg^<2+> which shows a little larger value. The Hamaker constant of latex particles in aqueous media was evaluated using the CCC and zeta potentials at CCC by applying the DLVO theory. The mean value of the Hamaker constant of latex perticles in aqueous media was obtained as 1.52x10^<-20> J. This value lies between literature values of the Hamaker constants (0.1-11x10^<-20> J) obtained by the colloid stability experiments, but it is four times larger in magnitude than that on the basis of the Lifshitz theory, 0.35x10^<-20> J.The second experiment on CCC determination was carried using different latex particles. The mean values of seven determinations of CCC were found to be 205 mM( =11 mM) for K<@D1+@>D1, 18.8 mM( =0.80 mM) for Mg<@D12+@>D, and 0.51 mM( =0.034 mM) for La<@D13+@>D1, the ratio of CCC being 100:9.1:0.25, respectively. The mean value of the Hamaker constant was obtained as 1.07x10<@D1-20@>D1.J. The second results with much less scattering justfy the first ones. Results of the individual research are referred to the list of publication attached. Less