RESUMO
Metal silicide nanowires (NWs) are very interesting materials with diverse physical properties. Among the silicides, manganese silicide nanostructures have attracted wide attention due to their several potential applications, including in microelectronics, optoelectronics, spintronics and thermoelectric devices. In this work, we exhibited the formation of pure manganese silicide and manganese silicide/silicon nanowire heterostructures through solid state reaction with line contacts between manganese pads and silicon NWs. Dynamical process and phase characterization were investigated by in situ transmission electron microscopy (in situ TEM) and spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM), respectively. The growth dynamics of the manganese silicide phase under thermal effects were systematically studied. Additionally, Al2O3, serving as the surface oxide, altered the growth behavior of the MnSi nanowire, enhancing the silicide/Si epitaxial growth and effecting the diffusion process in the silicon nanowire as well. In addition to fundamental science, this significant study has great potential in advancing future processing techniques in nanotechnology and related applications.
RESUMO
In this study, the catalytic efficiency of four recombinant CRL (Candida rugosa lipase) isozymes (LIP1-LIP4) towards the production of fatty acid methyl ester (FAME) was compared and evaluated as an alternative green method for industrial applications. The results indicated that the recombinant C. rugosa LIP1 enzyme exhibited the highest catalytic efficiency for FAME production compared to the recombinant C. rugosa LIP2-LIP4 enzymes. The optimal conditions were as follows: pH 7.0, methanol/soybean oil molar ratio: 3/1, enzyme amount: 2U (1.6 µL), reaction temperature: 20°C, 22 h of reaction time, and 3 times of methanol addition (1 mol/6h), and resulted in 61.5 ± 1.5 wt.% of FAME conversion. The reaction product contained also 10 wt.% of DAG with a ratio of 1,3-DAG to 1,2-DAG of approximately 4:6, and can be potentially used in industrial applications as a food emulsifier.