Organic/Metallic Nanohybrids Based on Amphiphilic Dumbbell-Shaped Dendrimers
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- 作者：Shi-Min Shau ; Chia-Cheng Chang ; Chia-Hao Lo ; Yi-Chu Chen ; Tzong-Yuan Juang ; Shenghong A. Dai ; Rong-Ho Lee ; Ru-Jong Jeng
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：April 25, 2012
- 年：2012
- 卷：4
- 期：4
- 页码：1897-1908
- 全文大小：774K
- 年卷期：v.4,no.4(April 25, 2012)
- ISSN：1944-8252
文摘
In this study, we synthesized a series of amphiphilic dumbbell-shaped dendrimers through the addition reactions of a hydrophilic poly(oxyalkylene) with hydrophobic dendrons based on 4-isocyanate-4鈥?(3,3-dimethyl-2,4-dioxo-azetidine)diphenylmethane with different numbers of branching generations. The addition reaction of azetidine-2,4-diones of dendrons to amines of poly(oxyalkylene) was proceeded by stirring the reactants in dry tetrahydrofuran (THF) under nitrogen at 60 掳C. In aqueous media, the dumbbell-shaped dendrimers self-assembled into micelles with their hydrophobic dendrons in the core and their hydrophilic poly(oxyalkylene) segments forming loops in the corona shell. Employing the unique self-assembled micelle structures as templates for subsequent chemical reduction of the Ag+ ions, we generated new types of organic/metallic [silver nanoparticle (AgNP)] nanohybrid clusters. The long poly(oxyalkylene) loops that extended into the aqueous phase complexed with the Ag+ ions, providing the suspension with steric stabilization to prevent the AgNPs from collision and flocculation. After reduction, the AgNPs were present in a homogeneous distribution in the round dendrimer micelle鈥搒tabilized nanoclusters. The diameter of each AgNP was less than 10 nm; the diameter of each round nanocluster was in the range of 50鈥?00 nm. The encapsulation efficiency of the AgNPs in micelles was about 54鈥?9% for the dumbbell-shaped dendrimer based organic/AgNP nanohybrid.