Robust Composite-Shell Microcapsules via Pickering Emulsification

• DOI: 10.1021/acsami.5b00494
• Publication Date: 2015-03-19T17:44:22Z
• Authors: Marcia W. Patchan; Benedict W. Fuller; Lance M. Baird; Paul K. Gong; Erich C. Walter; Brendan J. Vidmar; Ike Kyei; Zhiyong Xia; Jason J. Benkoski
• Keywords: Polyurea; Isophorone diisocyanate; Diethylenetriamine; Polyethylenimine

Microencapsulation technology has been increasingly applied toward the development of self-healing paints. Added to paint as a dry powder prior spraying, microcapsules store liquid that can repair protective barrier layer if released into scratch. However, will not occur unless withstand spray-painting, aggressive solvents in paint, and long-term exposure elements. We have therefore developed one-pot synthesis for production Pickering with outstanding strength, solvent resistance, properties. Octadecyltrimethoxysilane-filled (OTS) form via standard interfacial polycondensation, except silica nanopowder (10-20 nm diameter) replaces conventional surfactant or hydrocolloid emulsifier. Isophorone diisocyanate (IPDI) OTS core reacts diethylenetriamine, polyethylenimine, water hard polymer shell along interface. Compared pure polyurea, silica-polyurea composite improves shelf life by 10 times. The addition SiO2 prevents leaching xylenes hexanes up 80 days, resulting survive nebulization through spray gun at 620 kPa 500 cSt fluid.