Improving the metal ion release from nanoparticles embedded in a polypropylene matrix for antimicrobial applications

Abstract

ABSTRACTNovel antimicrobial materials can be produced by adding copper nanoparticles (CNPs) into a polymeric matrix. To improve the behavior of these systems, the effect of different variables on the dispersion of copper metal nanoparticles embedded in a polypropylene matrix by melt mixing and its ion release was analyzed. The variables studied were predispersion of particles in liquid solvents, polymer molecular weight, melt mixing conditions, addition of a compatibilizer agent, two‐step melt mixing, and surface functionalization of the metal particles. Our results show that by modifying these variables, a significant improvement in the filler dispersion, as quantified by optical microscope, can be obtained. For instance, the original CNP agglomerates can be reduced from an average size of 70 µm to a final average size of 30 µm and a larger amount of nanometric agglomerates by using a compatibilizer or predispersed nanoparticles. Moreover, by using surface‐functionalized CNPs, micrometric agglomerates were not observed. Noteworthy, there is a direct relationship between the filler dispersion and the release of biocide copper ions when improvements were larger than a certain threshold with increases as high as 40%. These findings can be used in the development of antimicrobial materials with tailored behavior. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41232.