Insight into Fractal Self-Assembly of Poly(diallyldimethylammonium chloride)/Sodium Carboxymethyl Cellulose Polyelectrolyte Complex Nanoparticles

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• 作者：Qiang Zhao ; Quanfu An ; Jinwen Qian ; Xuesan Wang ; Yang Zhou
• 刊名：Journal of Physical Chemistry B
• 出版年：2011
• 出版时间：December 22, 2011
• 年：2011
• 卷：115
• 期：50
• 页码：14901-14911
• 全文大小：1582K
• 年卷期：v.115,no.50(December 22, 2011)
• ISSN：1520-5207

文摘

Poly(diallyldimethylammonium chloride)-sodium carboxymethyl cellulose polyelectrolyte complexes (PDDA-CMCNa PECs) solids were prepared and dispersed in NaOH aqueous solution. Self-assembly of PECs nanoparticles during the solvent evaporation was examined by field emission electron microscopy (FESEM), atomic force microscopy (AFM), and fractal dimension analysis. It was found that tree-shaped fractal patterns formed after the solvent (water) was dried at ambient temperatures, and the fractal pattern is composed of needle-shaped PEC aggregate (PECA) nanoparticles. Time-dependent FESEM observation revealed that the fractal pattern started with the formation of initial nucleon and it is growing, during which the diffusion limited aggregation (DLA) mechanism revealed and made the pattern branched. Physical insight into the DLA mechanism was discussed in detail. Effects of PEC concentrations, PEC compositions, solvent evaporation temperatures, pH of PEC dispersion, and chemical structures of PECs on the formation of self-assembled fractal pattern were studied. Generally, it was found that the morphologies, charge characters of PEC particles, and the solvent evaporation conditions play important roles during the fractal self-assembly process.