Functional colloidal particles stabilized by layered silicate with hydrophilic face and hydrophobic polymer brushes

Abstract

In this study, we describe a new strategy for producing narrowly dispersed functional colloidal particles stabilized by a nanocomposite with hydrophilic clay faces and hydrophobic polystyrene (PS) brushes on the edges. This method involves preparation of polymer brushes on the edges of clay layers and Pickering suspension polymerization of styrene in the presence of the nanocomposites. PS brushes on the edges of clay layers were prepared by atom transfer radical polymerization. X-ray diffraction and thermogravimetric analysis results indicated that PS chains were grafted to the edges of clay platelets. Transmission electron microscope results showed that different morphologies of clay-PS particles could be obtained in different solvents. In water, clay-PS particles aggregated together, in which PS chains collapsed forming nanosized hydrophobic domains and hydrophilic clay faces stayed in aqueous phase. In toluene, clay-PS particles formed face-to-face structure. Narrowly dispersed PS colloidal particles stabilized by clay-PS were prepared by suspension polymerization. Because of the negatively charged clay particles on the surface, the zeta potential of the PS colloidal particles was negative. Positively charged poly(2-vinyl pyridine) (P2VP) chains were adsorbed to the surface of PS colloidal particles in aqueous solution at a low pH value, and gold nanoparticles were prepared in P2VP brushes. Such colloidal particles may find important applications in a variety of fields including waterborne adhesives, paints, catalysis of chemical reactions, and protein separation. V

Facile fabrication of nanocomposite microspheres with polymer cores and magnetic shells by Pickering suspension polymerization

“…Pickering emulsion droplets are also used as versatile polymerization vessels to fabricate hybrid polymer spheres and capsules with supracolloidal structures [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. The solid particles first self-assemble at the liquid-liquid interface and act as effective stabilizers during the polymerization process, eliminating the need for any conventional stabilizers.…”

“…Such a surfactant-free emulsion polymerization process, called Pickering emulsion polymerization, is more attractive for preparation of hybrid beads than the conventional emulsion polymerization method. Polymerizations based on Pickering emulsion include Pickering miniemulsion polymerization, Pickering suspension polymerization, Pickering dispersion polymerization and Pickering emulsion interface-initiated atom transfer radical polymerization (PEII-ATRP) [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. Magnetic microparticles with poly(methyl methacrylate) (PMMA) [35] or polyaniline (PANI) [44] cores and Fe 3 O 4 nanoparticle shells have been prepared by Pickering suspension polymerization; polystyrene (PS)-Fe 3 O 4 microparticles have been produced by Pickering dispersion polymerization [36].…”

CHAPTER 3. Polymer Colloidal Particles Prepared by Pickering Emulsion Polymerization or Self-Assembly Method

“…33,34 Wu and coworkers anchored ATRP initiator to the edges of clay particles, and prepared PS brushes on the edges of clay particles by ATRP (Figure 3.7). 35 The clay particles with hydrophilic faces and hydrophobic PS brushes on the edges can be used as efficient stabilizers in Pickering suspension polymerization of styrene. Figures 3.8a and b show TEM images of PS colloidal particles.…”

Slightly surface-functionalized polystyrene microspheres prepared via Pickering emulsion polymerization using for electrophoretic displays

“…Pickering emulsion/suspension polymerization has been proven as a fascinating method to fabricate polymer microspheres or polymer/inorganic nanocomposite microspheres [1][2][3][4][5][6][7][8][9][10][11][12]. It has been found that the size and morphology of polymer microspheres prepared by Pickering emulsion polymerization are highly depended on the surface structures of the solid particles [13,14].…”