title: Synthesis and characterization of polyacrylonitrile nanoparticles by dispersion/emulsion polymerization process.
abstract: Polyacrylonitrile nanoparticles in sizes ranging from approximately 35 to 270 nm were prepared by dispersion/emulsion polymerization of acrylonitrile in a continuous aqueous phase in the presence of potassium persulfate as initiator and various alkyl-sulfate and sulfonate surfactants. The influence of various polymerization parameters (e.g., concentration of monomer and initiator, type and concentration of surfactant, temperature and time of polymerization, ionic strength, pH and co-solvent concentration) on the properties (e.g., size and size distribution, yield, stability, etc.) of the particles has been investigated. The polymerization of acrylonitrile may occur in two major locations: in the aqueous continuous phase (dispersion polymerization) and/or within the surfactant micelles (emulsion polymerization). A discussion concerning the role of these two mechanisms under different conditions, including comparison with previous literature, is also presented. Surface and bulk characterizations of the particles were performed by methods such as transmission and scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, zeta potential, and gravimetric measurements.
authors: Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel.
authors: Lior
authors: L
authors: Boguslavsky
authors: Sigal
authors: S
authors: Baruch
authors: Shlomo
authors: S
authors: Margel
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis* / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D053758:Nanoparticles / Q000737:chemistry*; D009994:Osmolar Concentration; D010316:Particle Size; D017680:Potassium Compounds / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D004655:Emulsions; D008823:Micelles; D017680:Potassium Compounds; D013431:Sulfates; D013501:Surface-Active Agents; D014867:Water; C010504:polyacrylonitrile; C009007:potassium persulfate