­­­Photopattern-Directed Electrodeposition of Microstructured Copper for Antibacterial Surface Coatings

Monday, 10 October 2022
D. J. Sconyers, C. M. Longo, and J. A. Maurer (US Army DEVCOM Armaments Center - Benet Laboratories)
The development of electrodeposited surfaces with antiviral or antibacterial properties is a critical need in light of the realities of current and future pandemics. Increased use of chemical disinfectants represents a growing environmental problem, and in many cases threatens the surface finish of decontaminated products. To engineer new solutions to this problem, we can mimic biological systems that exhibit self-cleaning or bactericidal properties. In nature, surface morphology at the micro- and nanoscale are known to dramatically affect the adhesion of microorganisms and viral particles. These kinds of defined patterns and textures may be realized artificially through directed electrodeposition of transition metals from aqueous solution onto material surfaces of interest. In this work, we demonstrate the generation of such surfaces, enabled by the coating of self-assembled monolayers (SAMs) of alkoxysilanes and alkylphosphonates onto mild steel. Photo-induced monolayer patterning (PIMP) has been employed to selectively generate defect sites in these molecular photomasks, characterized by contact angle (CA) measurements, Fourier-transform infrared spectroscopy (FTIR) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). The electrolytic deposition of copper from aqueous solution onto the exposed steel in our photopatterned systems has been shown to result in variable surface microstructure. In addition, we will discuss biological assays to determine bacterial viability on the finished steel/copper surface.