MEASUREMENT OF LONG-RANGE DEPLETION ENERGIES BETWEEN A COLLOIDAL PARTICLE AND A FLAT SURFACE IN MICELLAR SOLUTIONS

被引：95

作者：

SOBER, DL ^{[1
]}

WALZ, JY ^{[1
]}

机构：

[1] TULANE UNIV,DEPT CHEM ENGN,NEW ORLEANS,LA 70118

来源：

LANGMUIR | 1995年 / 11卷 / 07期

关键词：

D O I：

10.1021/la00007a006

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The interaction energies between colloidal polystyrene latexes and a flat plat have been measured in the presence of cetyltrimethylammonium bromide (CTAB) micelles using total internal reflection microscopy (TIRM). Long range attractive depletion forces were observed down to micelle concentrations of 0.02% vol. Potential minima ranging from 1.5 to 6 kT were measured at separation distances of 50-70 nm, with attractive interactions extending well above 100 nm separation. The relationship between the depth of the potential minima and the micelle volume fraction was found to agree well. with the predicted contact potential for a hard-sphere-hard-wall interaction between a sphere and a flat plate. At CTAB concentrations greater than 2 mM (0.08% vol, micelles) the onset of an oscillatory energy profile was observed, thus indicating a structural contribution to the overall interaction energy.

引用

页码：2352 / 2356

页数：5

共 35 条

[11] LIPOID PH INDICATORS AS PROBES OF ELECTRICAL POTENTIAL AND POLARITY IN MICELLES [J].