Organic/Metallic Nanohybrids Based on Amphiphilic Dumbbell-Shaped Dendrimers
| Autor: | Ru-Jong Jeng, Yi-Chu Chen, Chia-Cheng Chang, Tzong-Yuan Juang, Rong-Ho Lee, Shi-Min Shau, Chia-Hao Lo, Shenghong A. Dai |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | ACS Applied Materials & Interfaces. 4:1897-1908 |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/am300499k |
| Popis: | 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'-(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 °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-stabilized nanoclusters. The diameter of each AgNP was less than 10 nm; the diameter of each round nanocluster was in the range of 50-200 nm. The encapsulation efficiency of the AgNPs in micelles was about 54-69% for the dumbbell-shaped dendrimer based organic/AgNP nanohybrid. |
| Databáze: | OpenAIRE |
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