Unexpected in-situ Free Radical Generation and Catalysis to Ag/Polymer Nanocomposite.

Yifan Pang,Jintao Wang,Chunhui Li,Liuhe Wei,Ruixue Wei

doi:10.1038/srep11993

Abstract

In this study, we discover unexpectedly that simple reaction of AgNO3 with oleic acid (OA) without solvent and surfactant could generate alkyl free radical which can catalyze double-bond polymerization of OA to form 1D polymeric oleic acid (POA) chain. In certain conditions, these POA chains circumvolute tightly each other to form microspheres and micro-plates in which monodisperse 4-5 nm Ag nanoparticles (NPs) were absorbed. It has been revealed that alkyl free radical generated during the redox reaction of carboxyl group of OA with Ag+ at relative low temperature. Then, the alkyl free radical catalyzed the double-bond polymerization of OA when the reaction temperature was further increased. Different from commonly-seen hydrophobic nanoparticles prepared in oleic acid-based microemulsion system, the nanocomposites cannot dispersed in n-hexane and could dispersed in ethanol and THF. The unusual dispersion behavior has been explained in terms of their structure and polarity of POA chain. The method combines the nucleation of Ag nanoparticles and the polymerization of monomer in a facile one-pot reaction, which provides a novel way for metal-polymer microsphere nanocomposite with low-cost, easy-operation and high-yield.

Highlights

Ag NPs and the double-bond polymerization of oleic acid occurred in same open vessel without further post-purification
Contrary to other commonly-seen nanomaterials prepared in oleic acid (OA)-based solution, the as-obtained nanocomposites can be dispersed in ethanol, but not in nonpolar solvents, such as n-hexane and cyclohexane
It is worthy to note that the polymeric oleic acid (POA) chains in reaction OA system could form spherical structure with the addition of hexane for it is insoluble in hexane

Summary

Introduction

Ag NPs and the double-bond polymerization of oleic acid occurred in same open vessel without further post-purification. Contrary to other commonly-seen nanomaterials prepared in OA-based solution, the as-obtained nanocomposites can be dispersed in ethanol, but not in nonpolar solvents, such as n-hexane and cyclohexane.

Results

Conclusion