The Interface Caused By The Emulsion Polymerization Core-shell Particles

In this dissertation,, nano-scale particles of hydrophilic PMAA shell and hydrophobic PSt core nanoparticles (PSt/PMAA), hydrophilic PAA core and hydrophobic PSt shell nanoparticles (PAA/PSt), P(St-co-AM)/NiS hybrid materials, PSt nano-hollow spheres, Ag@PSt hybrid materials and CdS@PSt hybrid materials have been successfully prepared byγ-irradiation technique and redox interfacial initiate microemulsion and emulsion polymerization, at room temperature and under ambient pressure. The possible formation mechanisms of redox interfacial initiation and nano-scale materials were suggested, and some factors of affecting the formation of nano-materials were studied.1. According to the knowledge of coordination chemistry, CHPO is hydrophobic and FeSO₄·7H₂O is hydrophilic, they can meet each other at the interface of oil-water, so radical can be formed at the interface and then initiate monomer polymerization. Composite polymer particles PSt/PMAA were prepared through two-stage interfacial-initiated seeded emulsion polymerization without any surfactant. We also use the same initiated system to initiate AA and St to synthesize PAA/PSt core/shell nanoparticles by one-step. We discuss the influence of the radius and disperse of nanoparticles by change second amount monomer, reaction temperature, different surfactants and other factors2. We combined interfacial initiated andγ-irridiation method to synthesize polymer/ inorganic hybrid materials, use the same initiated system to synthesize PSt/PAM core/shell nanoparticles through two-stage interfacial-initiated seeded emulsion polymerization. Then we enraped NiS nanoparticles onto the functional core/shell PSt/PAM when sodium thiosulfate(Na₂SSO₃) is utilized as sulfur source and NiSO₄ as metal source respectively byγ-irridiation.3. As a very interesting work of my dissertation, Interfacial-initiated polymerizations of styrene (St) were carried out in inversed and normal emulsion with cumene hydroperoxide (CHPO) and ferrous sulfatea (FeSO₄)/disodium ethylenediaminetetraacetate (NaEDTA)/sodium formaldehyde sulfoxylate (SFS) as the redox initiation system. The water-soluble Fe²⁺-NaEDTA-SFS acted as the reducing component and the oil-soluble CHPO as the oxidant component. Therefore, the primary radicals were produced mainly at the oil/water interface to initiate the polymerization of St. Thus, sub-micrometer hollow polystyrene (PSt) spheres were obtained in this one-stage polymerization, which was supported by the techniques of transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM).4. Sub-micrometer hollow polystyrene (PSt) spheres can be obtained by interfacial-initiated emulsion polymerization in one-stage. We can utilize the predominance of fabrication of nanoparticles byγ-irridiation and the method of interfacial-initiated method to synthesize various polymer encapsulated onto inorganic hybrid materials through two steps, such as: Ag@PSt and CdS@PSt hybrid materials.5. Because the hydromethylcellulose sodium (HMMC) have many functional hydroxyl and have good water-solubility. When the HMMC was soluble in water, its chains are unfolded, so we can use the HMMC to fabricate nano-rod and nano-wire as good template. The experimentation results can give us good proof to illuminate the HMMC is a good template in fabricate nano-rods and nano-wires. Without the HMMC, we can get the spheres nano-metal sulfide.