The Structure-Function Relationship of PAMAM Dendrimers as Robust Oil Dispersants-资料下载-美国布鲁克海文仪器公司

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阅读：248 发布时间：2015-3-12

PAMAM dendrimers have recently been investigated as efficient and biocompatible oil

11 dispersants utilizing their encapsulation capacity; however, their high cationic charge density has

12 been shown to be cytotoxic. It is therefore imperative to mitigate cationic charge-induced

13 toxicity and understand the effects of such changes. Presented here is a synergistic experimental

14 and computational approach to examine the effects of varying terminal surface charge on the

15 capacity of dendrimers to disperse model liner, polycyclic aromatic, and hybrid hydrocarbons.

16 Uncharged dendrimers collapse by forming intra-molecular hydrogen bonds, which reduce the

17 hosting capability. On the other hand, changing the surface charges from positive to negative

18 greatly shifts the pKa of tertiary amines of the PAMAM dendrimer interior. As a result, the

19 negatively charged dendrimers have a significant percentage of tertiary amines protonated,

20 ~30%. This unexpected change in interior protonation state cause electrostatic interactions with

21 the anionic terminal groups, leading to contraction and a marked decrease in hydrocarbon

22 hosting capacity. The present work highlights the robust nature of dendrimer oil dispersion and

also illuminates potentially unintended or unanticipated effects 23 of varying dendrimer surface

24 chemistry on their encapsulation or hosting efficacy, which is important for their environmental,

25 industrial, and biomedical applications.