High-Resolution Microscopical Studies of Contact Killing Mechanisms on Copper-Based Surfaces.

The mechanisms of bacterial contact killing induced by Cu surfaces were explored through high-resolution studies based on combinations of the focused ion beam (FIB), scanning transmission electron microscopy (STEM), high-resolution TEM, and nanoscale Fourier transform infrared spectroscopy (nano-FTIR) microscopy of individual bacterial cells of Gram-positive in direct contact with Cu metal and Cu5Zn5Al1Sn surfaces after high-touch corrosion conditions. This approach permitted subcellular information to be extracted from the bioinorganic interface between a single bacterium and Cu/Cu5Zn5Al1Sn surfaces after complete contact killing. Early stages of interaction between individual bacteria and the metal/alloy surfaces include cell leakage of extracellular polymeric substances (EPSs) from the bacterium and changes in the metal/alloy surface composition upon adherence of bacteria.

A novel methodology to study antimicrobial properties of high-touch surfaces used for indoor hygiene applications-A study on Cu metal.

Metal-based high-touch surfaces used for indoor applications such as doorknobs, light switches, handles and desks need to remain their antimicrobial properties even when tarnished or degraded. A novel laboratory methodology of relevance for indoor atmospheric conditions and fingerprint contact has therefore been elaborated for combined studies of both tarnishing/corrosion and antimicrobial properties of such high-touch surfaces. Cu metal was used as a benchmark material.

The nature of self-assembled octadecylphosphonic acid (ODPA) layers on copper substrates.

Hypothesis: The self-assembly of amphiphilic molecules onto solid substrates can result both in the formation of monolayers and multilayers. However, on oxidized and non-oxidized copper (Cu), only monolayer formation was reported for phosphonic acids possessing one phosphate head group. Here, the adsorption of octadecylphosphonic acid (ODPA) on Cu substrates through a self-assembly process was investigated with the initial hypothesis of monolayer formation.

Co-Adsorption of HO, OH, and Cl on Aluminum and Intermetallic Surfaces and Its Effects on the Work Function Studied by DFT Calculations.

The energetics of adsorption of HO layers and HO layers partially replaced with OH or Cl on an Al(111) surface and on selected surfaces of intermetallic phases, MgSi and AlCu, was studied by first-principle calculations using the density function theory (DFT). The results show that HO molecules tended to bind to all investigated surfaces with an adsorption energy in a relatively narrow range, between -0.8 eV and -0.

Analysis of Historic Copper Patinas. Influence of Inclusions on Patina Uniformity.

The morphology and elemental composition of cross sections of eight historic copper materials have been explored. The materials were taken from copper roofs installed in different middle and northern European environments from the 16th to the 19th century. All copper substrates contain inclusions of varying size, number and composition, reflecting different copper ores and production methods.