Dependency of Particle Sizes and Colloidal Stability of Polyelectrolyte Complex Dispersions on Polyanion Structure and Preparation Mode Investigated by Dynamic Light Scattering and Atomic Force Micros

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• 作者：Marcela Mihai ; Ecaterina Stela Dragan ; Simona Schwarz ; Andreas Janke
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：July 26, 2007
• 年：2007
• 卷：111
• 期：29
• 页码：8668 - 8675
• 全文大小：568K
• 年卷期：v.111,no.29(July 26, 2007)
• ISSN：1520-5207

文摘

Polyelectrolyte complex (PEC) dispersions were prepared by controlled mixing of three random copolymersof sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) with either t-butyl acrylamide (TBA) [P(AMPS₅₄-co-TBA₄₆) and P(AMPS₃₇-co-TBA₆₃)] or methyl methacrylate (MM) [P(AMPS₅₂-co-MM₄₈)] with an ionene-type polycation, containing 95 mol % N,N-dimethyl-2-hydroxypropyleneammonium chloride repeat units(PCA₅), with their structural characteristics being deeply investigated by dynamic light scattering (DLS) andatomic force microscopy (AFM). Shape, size, and polydispersity of the PEC dispersions were directly observedby AFM as a function of polyanion structure, the ratio between charges, n^-/n⁺, and the titrant addition rate(TAR). The particle sizes increased and the colloidal stability decreased with the increase of the nonioniccomonomer content and with the decrease of TAR. It was demonstrated that the medium particle sizes of thecomplex nanoparticles adsorbed on silicon wafers measured by AFM, in the dry state, were close but alwayslower than those measured by DLS, both before and after the complex stoichiometry.