Grafting shell-functionalized polymeric

There is a wide range of morphologies and compositions of polymeric microspheres. Core-shell microbeads can be created by sequentially polymerizing vinyl monomers, typically methacrylates and styrene. Each layer may consist of a homopolymer or a copolymer in the copolymers multifunctional vinyl monomers (e.g., diacrylates and divinylbenzene) may be used to create a cross-linked material. An optional final step can be grafting of functional groups to the surface in order to enhance compatibility to the surrounding medium. 

The glassy shell does not need to be crosslinked, since it is grafted to the crosslinked rubbery core. Sometimes the shell can be crosslinked and some reactive functions (such as glycidyl methyl methacrylate) may be grafted onto the surface at the end of the polymerization step. 

A wide variety of polymer microspheres can be made by dispersion polymerization. A key component in all of these systems is the stabilizer (dispersant) both during particle formation and for the stability of the resulting colloidal particles. Functionality can be introduced into colloidal particles in various ways by copolymerization of functional monomers (like HEMA), or incorporation of functional dispersants, initiators, chain transfer agents, or macromonomers. Many different types of macromonomer are prepared and used to prepare functional microspheres. Amphiphilic macromonomers provide a particularly versatile component in these systems, being the source of both stabilizer and functional residue. They act as stabilizer because they are covalently grafted onto the particles surface by copolymerization with main monomers, and form tightly bound hairy shells on the particles surface. 

Section 19.S.1.2), and reported increases in toughness comparable to those achieved with CTBN. A further, but inconclusive, study compared pre-formed poly(n-butyl aciylate)-based particles made by emulsion and by suspension polymerization [97]. Dispersion polymerization in an epoxy resin has been used to give directly dispersions of acrylic rubber particles in the epoxy for subsequent use in toughening epoxy resins [98]. Core-shell toughening particles comprising 70 wt% of CFOSslinked polybutadiene cores, with a grafted functionalized shell have been claimed [99] to improve the fracture toughness of a methylene dianiline cured epoxy resin by a factor of 10. 

An efficient one-pot synthesis of core/shell TiO /PANI-NPs from meth-acrylic acid-functionalized TiO -NPs by self-catalyzed hydroamination and oxidative polymerization of aniline was demonstrated by Bae et al. [118]. Core/shell-structured TiO /PANI nanocomposite was also fabricated by grafting aniline on aminobenzoate monolayer that is chemically adsorbed on the TiO nanocrystal surface [119]. Ferromagnetic semiconducting PANI/TiO nanocomposites [96], PANI/TiO nanocomposite photocatalysts [97], as well as composites of self-assembled PANI nanostructures with TiO -NPs [88] or TiO nanotubes [98] were synthesized by... 

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