One-Component Gels Based on Peptidic Dendrimers: Dendritic Effects on Materials Properties

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• 作者：Christine S. Love ; Andrew R. Hirst ; Victor Chechik ; David K. Smith ; Ian Ashworth ; and Colin Brennan
• 刊名：Langmuir
• 出版年：2004
• 出版时间：August 3, 2004
• 年：2004
• 卷：20
• 期：16
• 页码：6580 - 6585
• 全文大小：203K
• 年卷期：v.20,no.16(August 3, 2004)
• ISSN：1520-5827

文摘

This paper describes the gelation of symmetric dendrimers based on building blocks constructed fromL-lysine. These dendrimers form gel-phase materials in nonpolar organic solvents. The thermal propertiesand concentration dependence of the gelation were investigated, and it was found that there was a cleardendritic effect on the behavior of the soft materials formed, with higher generation dendrimers givingrise to more thermally stable gels. Variable temperature ¹H NMR studies indicated that this behavior wasprobably a consequence of more extensive interdendrimer hydrogen bonding occurring between the peptidicgroups in the higher generation dendrimers. The supramolecular aggregates were found to have a fibrillarstructure, with the dimensions and alignment of the fibers being dependent on dendritic generation.Circular dichroism measurements confirmed that these fibers possessed chiral organization of the peptidicgroups on the supramolecular (nano) scale, assigned as helicity. This paper indicates that dendriticfunctionalization provides a useful way of tuning gel-phase materials properties, with clear dendriticeffects on gel formation being quantified for the first time, hence illustrating the way dendriticfunctionalization can play a positive role in the formation of highly functional organic materials withdesirable properties.