Synthesis And Properties Of Polymer-Inorganic Composite Janus Nanosheets

Exploration of Janus materials with two different compositions compartmentalizeddistinctly onto the same surface is expected to provide an effective solution to thefunctionalization and dispersibility of nanomaterials. However, it is a great challenge toprepare Janus colloids due to their complex structures, so it is key to develop newmethods to large scale production of Janus colloids. In this paper, we developed a simpleapproach to large scale fabricate polydivinylbenzene/silica Janus composite nanosheetsthrough emulsion interfacial sol-gel method combined with radical polymerization.Firstly, under acidic condition at room temperature, self-organized interfacial sol gelprocess of the three silanes occurs to form inorganic Janus hollow spheres. Both interiorand exterior surfaces of the shell are smooth. Then, Janus composite hollow spheres aresynthesized by initiating polymerization of DVB onto the interior surface of the silicalayer. Although the exterior surface keeps smooth, the interior surface becomes coarse.By crushing the hollow spheres with colloid milling creates Janus composite nanosheets.One side of the Janus nanosheets is rough corresponding to polymer, while the other oneis smooth corresponding to silica. The cross-sectional dimension of the nanosheets istunable by controlling both the mill spacing between the rotators and milling time.Content and thickness of polymer and silica layers are tunable with reagent feedingamount. In addition, MPS covalently bind polmer layer with silica layer. The Januscomposite nanosheets can serve as solid surfactants to stabilize emulsion droplets, whichare tolerant against solvents. Janus balance of the composite nanosheets is tunablecrossing from more lipophilic to hydrophilic by alteration of polymer content. Thereafter,continuous phase of the emulsions can be inverted. This paper provides a new idea oflarge scale production of Janus composite nanosheets.