Synthesis of latex based antibacterial acrylate polymer/nanosilver via in situ miniemulsion polymerization

Silver nanoparticles were incorporated into poly-{methyl methacrylate-butyl acrylate-acrylic acid} using two different approaches. The first approach was based on dispersing the nanosilver particles in acrylic latex (previously synthesized by the emulsion polymerization) and the second is the in situ polymerization of acrylate monomers in the presence of silver nanoparticles by miniemulsion polymerization. Miniemulsion polymerization can yield a better dispersion of nanosilver in the polymeric particles because organic particles can be dispersed directly in the monomer droplets becoming encapsulated upon polymerization. Morphological investigations were performed using SEM and TEM. FTIR and thermal analyses revealed the silver nanoparticles to be located in the polymeric structure of latex. The nanocomposite latex was compared with the neat latex of the same monomer structure. A comparison of these results showed an increase in the degradation temperature and glass transition temperature (T (g) ) compared to the blank latex. The antibacterial properties were determined using the disc diffusion method against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli). The nanocomposite synthesized via in situ miniemulsion polymerization showed highly potent antibacterial activity toward both gram-positive and gram-negative bacteria comparing the neat latex and the blended nanocomposite, which makes it useful for a wide range of biomedical and general applications.