Programa de Ingeniería Molecular, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas 152, 07730, México, Distrito Federal, México.
J Chem Phys. 2011 Oct 7;135(13):134704. doi: 10.1063/1.3644769.
Recently reported colloidal aggregation data obtained for different monovalent salts (NaCl, NaNO(3), and NaSCN) and at high electrolyte concentrations are matched with the stochastic solutions of the master equation to obtain bond average lifetimes and bond formation probabilities. This was done for a cationic and an anionic system of similar particle size and absolute charge. Following the series Cl(-), NO(3)(-), SCN(-), the parameters obtained from the fitting procedure to the kinetic data suggest: (i) The existence of a potential of mean force (PMF) barrier and an increasing trend for it for both lattices. (ii) An increasing trend for the PMF at contact, for the cationic system, and a practically constant value for the anionic system. (iii) A decreasing trend for the depth of the secondary minimum. This complex behavior is in general supported by Monte Carlo simulations, which are implemented to obtain the PMF of a pair of colloidal particles immersed in the corresponding electrolyte solution. All these findings contrast the Derjaguin, Landau, Verwey, and Overbeek theory predictions.
最近报道的胶体聚集数据是针对不同单价盐（NaCl、NaNO(3) 和 NaSCN）在高电解质浓度下获得的，并与主方程的随机解相匹配，以获得键平均寿命和键形成概率。这是针对具有相似粒径和绝对电荷的阳离子和阴离子系统进行的。根据 Cl(-)、NO(3)(-)、SCN(-) 的顺序，从拟合动力学数据的过程中获得的参数表明：(i) 对于两种晶格，均存在平均力势（PMF）势垒且其呈上升趋势。(ii) 对于阳离子系统，PMF 在接触处呈上升趋势，而对于阴离子系统，其呈几乎恒定的值。(iii) 次级最小值的深度呈下降趋势。这种复杂的行为通常得到蒙特卡罗模拟的支持，这些模拟是为了获得一对胶体粒子在相应电解质溶液中的 PMF 而实施的。所有这些发现都与德热纳、朗道、维尔威和奥弗贝克理论的预测形成对比。
