| A new technique, hydrodynamic fingerprinting, is presented for the characterization and study of colloidal dispersions on the basis of their hydrodynamic behavior. In the hydrodynamic fingerprint the hydrodynamic size as measured by photon correlation spectroscopy is presented as a function of two colloidal state variables simultaneously. There is an acid-base variable, pH, and a conductivity variable, p{dollar}lambda{dollar}.; Hydrodynamic fingerprinting is applied to four polymer latexes, two polystyrene latexes, one with a sulfate surface and one with a carboxyl surface, and two methyl maehacrylate-ethyl acrylate latexes, one of which contains 2 % acrylic acid. It is shown that hydrodynamic fingerprinting can be used to study colloidal stability, expandable properties of colloids, time effects in colloidal solutions, and the surface chemistry of the colloid-solution interface.; A combinatorial hydrodynamic-electrokinetic fingerprinting analysis of the acidic copolymer latex is also presented. This approach can be used to gain insight into ambiguous electrokinetic behavior, and to study the surface charge characteristics of colloidal dispersions. |
