Selective preparation of novel fluoroalkyl end-capped co-oligomeric nanocomposite-encapsulated magnetites and magnetite-adsorbing co-oligomeric nanoparticles

Abstract

New crosslinked fluoroalkyl end-capped co-oligomeric nanocomposite- encapsulated magnetic nanoparticles, prepared by the deprotecting reactions of corresponding fluorinated co-oligomers containing oxime-blocked segments in the presence of magnetic nanoparticles, were produced with nanometer-scale diameters (with diameters in the range of 154-192 nm). The nanoparticles exhibited good dispersibility in traditional organic solvents. They were applied as a surface modification to poly(methyl methacrylate), resulting in good oleophobicity imparted by the fluorine and magnetic properties arising from the encapsulated magnetic nanoparticles. Fluoroalkyl end-capped 2-acrylamido-2- methylpropanesulfonic acid co-oligomers containing adamantane segments form nanometer-sized controlled fine particles in methanol and can interact with magnetic nanoparticles to form fluorinated betaine-type co-oligomeric nanocomposite-encapsulated magnetic nanoparticles (with an average particle size of 25-183 nm). These fluorinated betaine-type nanocomposite-encapsulated magnetic nanoparticles exhibit the lower critical solution temperature (LCST) characteristic in organic media such as t-butyl alcohol and were found to effectively decrease the LCST through the encapsulation of magnetic nanoparticles in fluorinated co-oligomeric nanoparticle cores. Interestingly, transmission electron microscopy images show that magnetic nanoparticles can be encapsulated inside the crosslinked fluorinated co-oligomeric nanocomposite cores; in contrast, magnetic nanoparticles are adsorbed on the surface of fluorinated betaine-type co-oligomeric nanocomposite cores. © The Society of Polymer Science, Japan (SPSJ) All rights reserved.