A General Nanocoating Method via Photoinduced Self-Initiation

Hybrid core-shell nanoparticles play a very significant role in many applications. Here, we report a light-induced oligomer coating on nanoparticles via Norrish type I reaction. The radical species generated via UV irradiation can chemically initiate the photoinitiators, which are then polymerized and deposited on inorganic nanoparticles via heterogeneous nucleation, forming a soft oligomer coating smaller than 40 nm. This coating method is versatile and potentially applicable to many different types of inorganic cores and their assemblies, making it a very useful technique for "freezing" nanoassemblies in solution. Moreover, these oligomer coatings containing radical species can also initiate surface polymerization of both styrenic and acrylic monomers with certain functionalities for different applications such as self-assembly, plasmon tuning, and pH sensing (3.5-4.5).