Effect of Ionic Binding on the Self-Diffusion of Anionic Dendrimers and Hydrophilic Polymers in Aqueous Systems as Studied by Pulsed Gradient NMR Techniques

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• 作者：Hé ; loï ; se Thé ; rien-Aubin ; X. X. Zhu ; Charles N. Moorefield ; Kishore Kotta ; George R. Newkome
• 刊名：Macromolecules
• 出版年：2007
• 出版时间：May 15, 2007
• 年：2007
• 卷：40
• 期：10
• 页码：3644 - 3649
• 全文大小：135K
• 年卷期：v.40,no.10(May 15, 2007)
• ISSN：1520-5835

文摘

Pulsed gradient NMR techniques including diffusion-ordered NMR spectroscopy have been usedto study the self-diffusion of three carboxylated dendrimers in aqueous solutions of neutral poly(vinyl alcohol)(PVA) and of cationic poly(allyl amine) (PAAm). The ionic interaction between the cationic PAAm network andthe anionic dendrimers had the most significant effect on the diffusion of the dendrimers in the system. Theself-diffusion coefficients of the dendrimers in PAAm were an order of magnitude lower than in PVA and morewidely distributed, and the activation energy for the displacement of the dendrimers in PAAm was higher thanthat in PVA. The effects of the dendrimer size, polymer concentration, and temperature on the diffusion of thedendrimers have also been studied.