Preparation Of PS - Based Microspheres By Microemulsion Polymerization And Its Application

Preparation and application of functional PS nanospheres have developed rapidly on not only the new technology but also the variety and performance of PS nanospheres which gradually spread to the product of monodisperse, controlled size, morphology and high properties especially of application in biomedical field, which is importance for clinical diagnosis, verify, immunological technique and cytology. Mini emulsion polymerization shows great potential application because of its special mechanism of nucleation.Basic violet (BV11:1) daylight fluorescent pigment resin was prepared by mini-emulsion polymerization of styrene and other functional monomers at the present of basic violet. The water soluble basic violet was firstly converted to hydrophobic brownish-black complex SDS-BV by interacting with SDS driven by electrostatic interaction, then dissolved by GMA. The effect of size and its distribution, type of surfactant, functional monmers and dispersive-protective agent dose on the brightness, penetrability, color fastness were investigated systematically. The concentration of anionic surfactant was decisive factor to affect the size of daylight fluorescent pigment resin spheres, hydroxyethyl cellulose had effect on the polymerization stability, resin size distribution and penetrability. The brightness of resin was dependent on the size and its distribution, nonionic surfactant and acrylonitrile functional monomer. The color fastness was decided by basic violet encapsulation efficiency and the type of functional monomers. The optimization was obtained in this study.In this paper, Poly(styrene-acrylate) latex with phosphate functional group (SA-PO) was prepared using mini-emulsion polymerization, then aniline was adsorbed on the surface by electrostatic interaction. Polyaniline (PANI) bonded SA (PANI-SA) composite was then prepared by in-situ chemical oxidation polymerization of aniline. FT-IR and UV-Vis spectra confirm the formation of the PANI-SA composite. Small spherical particles of10-20nm in diameter on the surface of SA latexes are observed by SEM and TEM. DSC and TGA results indicate that there are chemical bonding formed between PANI and SA, and PANI in the PANI-SA composite can increase the glass transition temperature (Tg) and thermal decomposition temperature (Td) of SA latex film effectively. Compared with PANI/polymer composite system, PANI-SA has two advantages:avoidance of aggregation problem of nanoscale polyaniline in polymer matrix and improvement of the interface adhesion between PANI and polymer matrix.In this paper, RhB-Labeled and CsA loaded PS nanospheres with controlled size and designed functional groups have been successfully synthesized via miniemulsion copolymerization with functional monomers. Size, size distribution and morphology are charactered by DLS and TEM, and CsA encapsulation efficiency is measured by HPLC. The biophysical properties of PS nanospheres were characterized by protein adsorption, blood and cell compatibility and cell penetrability. The results indicated that PEG modified PS nanospheres show the outstanding properties:low size distribution (0.164), high encapsulation efficiency (98.3%), re-calcification time longer than positive control (50%), low hemolysis ratio (3.19%) and high cell viability (95.3%), which lays a good foundation for the drug delivery system design.