A method based on nanosecond laser treatment was used to design superhydrophobic and superhydrophilic aluminum alloy substrates showing enhanced cytotoxic activity with respect to Escherichia coli K12 C600 strain. It was shown that the survival of cells adhered to the superhydrophobic substrates was significantly affected by the presence of organic contaminants, which are ubiquitous in hospital practice and the food industry. The peculiarities of the texture also played a notable role in antibactericidal activity. It was found that the superhydrophilic surfaces had much higher toxicity than the superhydrophobic ones, which was explained by the mechanisms of adhesion of cells to the surface. Scanning electron microscopy and tomographic reconstruction of the adhered cells were used to study the variation of cell morphology after attachment to surfaces with different wettability. It was shown that the cytotoxicity of superhydrophobic surfaces could be significantly enhanced by using the combined antimicrobial action of bacteriophages and the superhydrophobicity of the objects.

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Abstract. The thermodynamic properties of the copper carbonates malachite and azurite have been studied by adiabatic calorimetry, by heat-flux Calvet Calorimetry, by differential thermal analysis (DTA) and by thermogravimetric (TGA) analysis. The heat capacities, C o of natural malachite and azurite have been measured between 3.8 and 300 K by low-temperature adiabatic calorimetry. The heat capacity of azurite exhibits anomalous behavior at low temperatures. At 298.15 K the molar 8298.15 heat capacities C ~ and the third law entropies o are 228.5 _+ 1.4 and 254.4 _+ 3.8 J mol-1 K-1 for azurite and 154.3+0.93 and 166.3• K -1 for malachite. Enthalpies of solution at 973 K in lead borate (2PbO'BzO3) have been measured for heat treated malachite and azurite. The enthalpies of decomposition are 105.1 +__ 5.8 for azurite and 66.1 +_ 5.0 kJ tool-1 for malachite. The enthalpies of formation from oxides of azurite and malachite determined by oxide melt solution calorimetry, are -84.7 + 7.4 and -52.5 __+ 5.9 kJ mol-1, respectively. On the basis of the thermodynamic data obtained, phase relations of azurite and malachite in the system Cu 2 + -HzO-CO2 at 25 and 75 ~ have been studied.

A method based on nanosecond laser processing was used to design superhydrophilic and superhydrophobic copper substrates. Three different protocols were used to analyze the evolution of the bactericidal activity of the copper substrates with different wettability. Scanning electron microscopy was used to study the variation of cell morphology after the attachment to superhydrophilic and superhydrophobic surfaces. The dispersions of Escherichia coli K12 C600 and Klebsiella pneumoniae 811 in Luria Bertani broth in contact with the superhydrophilic copper surface showed enhanced bacterial inactivation, associated with toxic action of both hierarchically textured copper surface and high content of Cu2+ ions in the dispersion medium. In contrast, the bacterial dispersions in contact with the superhydrophobic copper substrates demonstrated an increase in cell concentration with time until the development of corrosion processes. The resistance of bacterial cells to contact the copper substrates is discussed on the basis of surface forces, determining the primary adhesion and of the protective action of a superhydrophobic state of the surface against electrochemical and biological corrosion.

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