Preparation Of Functionalized Polystyrene Nanoparticles And Its Application In Heavy Metal Sensor

The size of polymer nanoparticle is between the transitional region of atomclusters and macro system, the characteristic of its high specific surface area made itobviously different from macro and micro system. Preparation of polymernanoparticles, especially the particle size is less than30nm particles is of greatsignificance in the field of biomedical polymer. The similarity size dependence andsimple adjustable functional surface with polymer nanoparticles and biologicalmacromolecules (such as amino acids and proteins) is the main direction of currentresearch. As carriers in biology, medicine, solid phase synthesis of organic materialsmonodisperse polystyrene microspheres have broad application, especially thenanoparticles with SH-surface modification has a widely used in drug release,biosensors, protein synthesis analysis. Sulphur of polystyrene resin can be used as aidentify components in heavy metal detection sensor; can detect arbitraryconcentration within a certain range of heavy metal ions.Based on conventional emulsion polymerization, differential micro-emulsionpolymerization changes the feeding way, add polymerization monomer viadifferential add monomer, monodisperse and small size polymer nanoparticles can besynthesised under low monomer/emulsifier ratio. Styrene and4-vinylbenzyl chlorideas comonomer, divinyl benzene as crosslinking agent, potassium peroxodisulfate(KPS) as initiator, and sodium dodecyl sulfate (SDS) as surfactant, chloromethylationpolystyrene microspheres were prepared by differential microemulsionpolymerization. Under Styrene/VBC=1:1; Mn1:Mn2=3:2; SDS:Mn=1:5(w/w) theparticle prepared with Dn of25nm. Thiol polystyrene (SHPS) nanoparticles can beprepared using the chloromethylation microsphere samples reaction with thiourea.The particle morphological was characterized with high resolution transmissionelectron microscope and dynamic light scattering method. Element analysis showedthat the chloromethyl group of chloromethylation microspheres can reach to9.40%and the SH-of the thiol polystyrene can reach to7.72%.The QCM electrode modifyed with thiol microspheres by self-assembly enables the adsorption ability of metal ions to electrode. The assembly and adsorptioncondition of the modified electrode were investigatied by AFM and SEM. Theadsorption performance of the sulphur microspheres to Au(Ⅱ) and Cu(Ⅱ) in aqueoussolution was investigated through static adsorption experiment. Results show thatthiol microspheres have a strong pH value dependence to the two kinds of ion, it canbe reached adsorption equilibrium within5min and the removal rate of Au(Ⅱ) andCu(Ⅱ) was96.42%and96.42%respectively.