Kinetic, physical and biological studies on some Nanocomposite Materials

Abstract

Poly (methyl methacrylate) (PMMA) nanocomposites with different amounts of nanofillers (Zinc oxide and silver) were prepared by in situ bulk polymerization method. ZnO and Ag nanoparticles were synthesized by a sol‒gel and a hydrothermal method, respectively. The effect of nanofillers concentration, in the range 0.1‒15 wt%, on the optical, biological, electrical properties and thermal decomposition kinetics of PMMA were investigated by XRD, FTIR, TEM, TG/DSC and UV–vis absorption spectra. Results demonstrated that the peaks observed in PMMA together with the peaks of the nanofillers, the intensity of which increases with increasing quantity and well dispersion of nanoparticles of in the polymeric matrix. The ZnO and Ag nanoparticles increased the thermal stability of the polymer that observed in the values of activation energy. The intensity of absorption bands in UV region is decreased with increasing the nanofillers content. The values of electrical conductivity of nanocomposites increase with nanofillers concentration. Polyaniline (PANI) nanocomposites with different amounts of nanofillers (Cerium oxide and silver) were prepared by chemical polymerization using ammonium persulfate (APS) as oxidant and HNO3 as doping agent, respectively. CeO2 and Ag nanoparticles were synthesized by a sol-gel andreduction using NaBH4methods, respectively.The effect of nanofillers content, in the range 1‒10 wt%, on the optical, removal of dye from aqueous solutions by adsorption process, electrical and electrochemicalproperties of PANI were examined by XRD, FTIR, TEM, SEM, TG and UV–vis absorption spectra.Results demonstrated that the intensity of the nanofillers peaks which increases with increasing the content. This confirms that the filler maintained its structure in the polymer and well dispersion of nanoparticles of in the polymeric matrix. The adsorptionperformance ofPANI/CeO2 was evaluated by removal of dye from aqueous solutions.The specific capacitance of PANI/CeO2 nanocomposites increasing as the doping concentration of the CeO2 increases. The use of CeO2 improves the performance of the composites as an effectivesupercapacitor. The values of electrical conductivity of PANI/Agnanocomposites increase with nanofillers concentration as well asthe ac-conductivity values of composites are higher than the dc-conductivity. Keywords: Nanoparticles; Nanocomposites;Non-isothermal decomposition kinetics; Optical properties; Adsorption isotherm; specific capacitance.