Characterization of poly-{trans-[RuCl2(vpy)4 ]-styrene-4-vinylpyridine} impregnated with silver nanoparticles in non aqueous medium

Abstract

A síntese e a caracterização de um novo filme polimérico composto por poli-{trans-[RuCl 2 (vpy) 4 ]-estireno-4-vinilpiridina} impregnado com nanopartículas de prata são descritas neste trabalho. Este material foi obtido por polimerização em meio não aquoso envolvendo o complexo mononuclear trans- [RuCl 2 (vpy) 4 ], o estireno (sty) e a 4-vinilpiridina (4-vpy), usando peróxido de benzoila como iniciador. As dimensões nanométricas das partículas de prata foram confirmadas através de microscopia eletrônica de transmissão (TEM) e por espectroscopia eletrônica no UV-visível. A morfologia do terpolímero foi caracterizada por microscopia eletrônica de varredura (MEV). As propriedades térmicas foram analisadas por termogravimetria (TGA) e calorimetria diferencial de varredura (DSC). A ação antimicrobiana do polímero impregnado com nanopartículas de prata foi avaliada utilizando microrganismos Gram positivo e Gram negativo, Staphylococcus aureus (ATCC 25923) e Escherichia coli (ATCC 25922), respectivamente. A atividade antimicrobiana do terpolímero com nanopartículas de prata foi confirmada pela presença de um halo de inibição do crescimento bacteriano nos meios de cultura semeados.The synthesis and characterization of a new polymeric material composed of poly-{trans-[RuCl 2 (vpy) 4 ]-styrene-4-vinylpyridine} impregnated with silver nanoparticles are here described. This material was obtained by a non aqueous polymerization reaction involving trans-[RuCl 2 (vpy) 4 ], styrene (sty) and 4-vinylpyridine (4-vpy), using benzoyl peroxide as initiator. The silver particles nanometric dimensions were confirmed by transmission electron microscopy (TEM) and UV-visible spectroscopy. The terpolymer morphology was characterized by scanning electron microscopy (SEM). Thermal properties were analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The antimicrobial action of the polymer impregnated with silver nanoparticles was evaluated by the use of Gram positive and Gram negative microorganisms, Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), respectively. The antimicrobial activity of the terpolymer with silver nanoparticles was confirmed by the presence of a bacterial growth inhibition halo in seeded culture media.Keywords: ruthenium complex, polymer, silver nanoparticles, antimicrobial IntroductionFunctional polymer networks have gained great importance in many fields of scientific research as well as in industrial applications. These applications will increase greatly due to the variety of possible modifications in the chemical and physical properties of these materials. 1 Network polymers based on styrene, prepared by well-developed suspension polymerization processes, retain many advantageous qualities for a microcomposite host matrix. These include ease of preparation, controlled surface area and porous structure, good thermal resistance and reasonable chemical inertness. 2 Polymers based on the application of coordination forces have been prepared recently. The f...