The generation of desired functional groups on poly(4-vinyl pyridine) particles by post-modification technique for antimicrobial and environmental applications

Abstract

Poly(4-vinyl pyridine) (p(4-VP)) particles were synthesized by a simple micro-emulsion polymerization technique using sodium dodecyl sulfate (SDS) as surfactant. The prepared p(4-VP) particles were then treated various modifying agents with different functional groups. The modifying agents used in the modification of p(4-VP) particles are N-alkyl quaternizing agents such as 2-bromo ethanol (OH), 4-bromo butyronitrile (CN), and 2-bromoethylamine hydrobromide (NH2). The functional groups on the modified p(4-VP) particles were confirmed by FT-IR spectrometry and zeta potential measurements. The size of p(4-VP) and modified p(4-VP) particles is between 300 and 700nm, and the zeta potentials of modified p(4-VP) particles were varied between 2 and 45mV. Moreover, a second post-modification was carried out on 4-bromo butyronitrile modified p(4-VP) particles by amidoximation. The modified p(4-VP) particles were also tested for their antimicrobial effects against various bacteria such as Staphylococcus aureus, Bacillus subtilis, and Escherichia coli. It was found that p(4-VP) do not posses antimicrobial properties, whereas the modified forms especially p(4-VP)+ and p(4-VP)+–NH3+ showed highly bactericidal characteristics. Due to the positive charge by means of new functional groups generated on p(4-VP)-based particles by modification, the absorption of oppositely charged reagents such as fluorescein sodium salt (FSS) was increased drastically. For example, the absorption capacity of unmodified p(4-VP) was increased to 93.3, 93.5, and 93.6 form 37.6mg for p(4-VP)+, p(4-VP)+–NH2, p(4-VP)+–NH3+, respectively. Moreover, upon modification, except Cu(II), Co(II) and Ni(II) absorption capacities were increased from about 15.9, and 22.1mg to 21.1 and 39,1mg per gram particles.