Kapitza conductance of silicon–amorphous polyethylene interfaces by molecular dynamics simulations
We use nonequilibrium molecular dynamics simulation to elucidate the interfacial thermal conductance between single-crystal silicon and amorphous polyethylene. In particular, we investigate the role of solid stiffness and the bonding strength across the interface on the interfacial thermal conductance. Simulations of interfacial scattering of individual phonon wave packets indicate that neither diffuse mismatch model nor acoustic mismatch model describes the interfacial scattering process quantitatively. In general, transmission coefficients for longitudinal phonons are significantly higher than those for transverse phonons. We also observe that anharmonic processes can be important for interfacial conductance.
Finding environmentally gentle methods to graft Lewis acid on the surface of mesoporous materials is a topic of current interest. Herein we describe the optimization of a preparation procedure of a mesoporous silica-supported ErIII catalyst using the microwave-assisted post-calcination functionalization of Mobil Composition of Matter-41 silica as the key step. The required time for functionalization was reduced from several hours to 10 min using sealed-vessel microwave technology. Control experiments using conventional heating at the same temperature demonstrated that the rate increase is owing to a simple thermal/kinetic effect as a result of the higher reaction temperature. The resulting ErIII catalyst was tested for the first time as a catalyst in the continuous flow deprotection of benzaldehyde dimethylacetal and a complete leaching study was performed.