Janus Nanoshards Prepared Based on High Internal Phase Emulsion Templates for Compatibilizing Immiscible Polymer Blends

Silica Janus nanoparticles have great potential to improve the compatibility of immiscible polymer blends due to their synergetic amphiphilicity and Pickering effect. However, a great challenge of the scalable production of Janus nanoparticles still remains because of the complex preparation procedure and strict synthesis conditions. Herein, high internal phase emulsion templates stabilized by hyperbranched vinyl-substituted polyethoxysiloxane alone are used as microreactors to realize the well-defined functionalization of porous materials in the oil phase and aqueous phase independently. Janus nanoshards (JNs) are then obtained via crushing the formed silica aerogels, followed by grafting polyolefin elastomer (POE) chains on the opposite surface with polystyrene (PS) chains. The morphology of the silica JNs is observed by field-emission scanning electron microscopy and transmission electron microscopy. The prepared silica JNs can anchor at the interface of PS/POE blends to manipulate the phase morphology and improve the adhesion of two phases. Synchronous strengthening and toughening of the polymer blends are achieved by using functional silica JNs as compatibilizers. This work proposes a new strategy for the large-scale production of silica JNs suitable for compatibilizing immiscible polymer blends.