Narrow Results

The segregation energy of diluted species in a matrix can be calculated by first principles. These calculations are generally very computational demanding. The existing empirical models which use the difference in surface tensions to predict the segregation energy are limited, because they do not take the surface orientation of the matrix into account. In this investigation a model was developed which can estimate the segregation energies of segregating species in a binary system. The model makes use of the sublimation energies and takes the orientation of the surface into account. The model shows that the driving force for segregation is not the difference in surface tensions (between the surface tension of the pure element and the surface tension of the element in the alloy) but the difference in surface energies. The results of the calculations were used to simulate the Ag and Sb segregation to the (111) surface of copper.

Bamboo charcoal (BC) accompanied silver (Ag) nanocomposite is synthesized through sol–gel method. The produced BC/Ag nanocomposite was surface modified by air and oxygen plasma treatments. Silver ions (Ag${}^{+}$) will serve to improve the antibacterial activity as well as the surface area of BC. Plasma treatment has improved the surface functional groups, crystalline intensity and antibacterial activity of the prepared nanocomposite. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies show that Ag nanoparticles have good agreement with BC and the particle size has a mean diameter of 20–40nm. We observe the carboxyl functional groups in Fourier transform infrared spectroscopy (FTIR) after the oxygen plasma treatment. Moreover surface area and adsorption were analyzed by using the Brunauer, Emmett and Teller (BET) surface area ($S_{\mathrm{\text{BET}}}$) and UV–Vis spectroscopy.