Hybrid (Ag)ZnO/Cs/PMMA nanocomposite thin films

Abstract

Combining well known oxide materials with biocompatible polymers such as chitosan (Cs) and antimicrobial agents such as Ag can bring new functionalities to materials for electronics and lead to new border applications in the field of stretchable wearable bioelectronics and drug delivery systems. The paper reports on new hybrid thin films based on zinc oxide (ZnO) and Ag:ZnO nanoparticles dispersed in chitosan and incorporated in poly(methyl methacrylate) (PMMA) matrix by a modified sol-gel method. The structure, morphology, optical, electrical and antimicrobial properties of the obtained hybrid ZnO/Cs/PMMA and Ag:ZnO/Cs/PMMA thin films have been investigated. For electric characterization, current-voltage, capacitance-voltage and dielectric constant-frequency curves of the one and two-layers hybrid thin films deposed in MIS structure have been recorded. The dielectric constant values between 9.5 and 14.9 at 20 kHz, in addition with low surface roughness, optimal optical transmittance in visible and near-infrared region of about 90% and optical band gap (Eg) values between 3.543 and 3.737 eV, indicate high potential applications of the obtained hybrid films in transparent bioelectronics. The antimicrobial activity of the hybrid sols used for the film's deposition and the resulted thin films have been investigated using the paper disc method on Mueller-Hinton agar against Gram negative E. coli and Gram positive S. aureus bacteria. Ag:ZnO/Cs/PMMA films showed good antimicrobial activity against S. aureus and E. coli.