Heterophase Polymerization as Synthetic Tool in Polymer Chemistry for Making Nanocomposites

Abstract

Summary: The paper considers various possibilities to produce inorganic -polymeric nanocomposites via aqueous heterophase polymerization. Special emphasis is placed on strategies to synthesize nanocomposite particles via joint nucleation or joint polymerization. The former strategy is used to make composite particles with CaCO 3 as inorganic component. The strategy of joint polymerization takes advantage from the condition that aqueous heterophase polymerization is a convenient possibility to synthesize amphiphilic block copolymers. This method relies on the fact that polymeric radicals can survive in isolated latex particles that are stabilized by hydrophilic blocks. This strategy can be successfully applied to produce silicacontaining block copolymer particles in a one-step procedure.

Molecular Aspects of Radical Polymerizations—The Propagation Frequency

“…It has been observed with advanced light scattering techniques that spontaneous emulsification of organic solvents, that do not swell nanoparticles, in water causes shell formation around the nanoparticles. [120] For example, formation of nanometer thick shells of oct-1-ene and hexane on polystyrene and silica nanoparticles has been proven. During emulsion polymerization, swelling and propagation takes place simultaneously.…”

Borderline Particles: Approaching the Limit between Colloidal Stability and Instability during Heterophase Polymerization

“…This fact is a kind of trademark of the ceric ion redox initiation and is supportive for the successful synthesis of block copolymers via free radical polymerization as discussed in ref . The particular role of the chain length of the water‐soluble polymeric reductant and of the PNIPAM middle block on the polymerization process has been discussed in ref . Moreover, it has been convincingly experimentally proven by reaction calorimetry that radical formation with poly(ethylene glycol) as reductant takes place exclusively at the methylol end groups and not additionally along the polyether chain (see ref…”

“…On the contrary, hydrophilic polymers as reductant cause the formation of block copolymer particles with ordinary SSM. In other studies, we have shown that in order to get stable block copolymer latexes with poly(ethylene glycol) as reductant, its molecular weight must be higher than about 2000 g mol −1 …”

“…If hydrophilic polymers with methylol end groups are used as reductant, amphiphilic block copolymer particles are accessible with controllable composition via sequential addition of various monomers . In fact, this is the free radical polymerization variant, which from the historical perspective, preceded what is known today as polymerization induced self‐assembly (PISA): utilizing controlled radical polymerization started with water‐soluble control agents .…”

Ellipsometric light scattering to probe the interface of colloids - current applications and future challenges

“…This experiment is one of the few studies in the field of the characterisation of the ion distribution about such large particles [7]. A related observation concerncs the wetting of colloidal interfaces in an aqueous medium by oct-1-en [15].…”