Enhancing antimicrobial performance and surface characteristics of glass fiber reinforced composites using chitosan-ZnO-CuO nanohybrids

Abstract

Enhancing the antimicrobial performance of construction materials such as Glass Fiber Reinforced Concrete (GFRC) is crucial for improving their durability and hygiene, particularly in environments prone to microbial contamination. In this study, hydrothermally synthesized Chitosan-ZnO-CuO nanohybrid composites were incorporated into GFRC to evaluate their antimicrobial efficacy and surface characteristics. Chitosan, a biocompatible and biodegradable polymer, was combined with zinc oxide and copper oxide nanoparticles to form multifunctional hybrids exhibiting synergistic antimicrobial behavior. The nanohybrids were doped into GFRC at concentrations of 1 %, 2 %, and 3 %, and their antimicrobial activity was tested against Escherichia coli, Candida albicans, and Trichophyton tonsurans. At 2 % doping, inhibition zones increased by 66.7 % for E. coli, 36.8 % for C. albicans, and 34.6 % for T. tonsurans compared to 1 % doping. However, efficacy declined at 3 %, suggesting an optimal concentration threshold. Surface roughness analyses revealed that increasing nanohybrid content enhanced surface topography, with Ra values rising from 0.14 µm to 0.95 µm, and Rmax peaking at 17.3 µm at 2 %. This increased surface roughness is believed to promote antimicrobial efficiency by creating a more irregular surface that disrupts microbial adhesion and biofilm formation, thereby synergizing with the nanohybrids’ biocidal action. These findings demonstrate that Chitosan-ZnO-CuO nanohybrids improve the hygienic and surface properties of GFRC, with optimal performance observed at 2 % loading. The study contributes to the development of advanced fiber-reinforced composites with dual mechanical and antimicrobial functionality for hygienically critical applications.