Carbon nanotubes (CNTs) functionalized by a nanothin poly(dopamine) (PDA) layer were produced by a one-pot, nondestructive approach, with direct polymerization of dopamine on the CNT surface. The thickness of the PDA layer can be well-controlled by the reaction time and the proportion of dopamine, and this thickness is found to be the key factor in controlling the dispersion of CNTs and the extent of the interfacial interactions between the CNT@PDA and epoxy resin. SEM results indicated that the dispersion of CNTs in epoxy was improved significantly by coating a nanothin PDA layer onto the CNT surface. In agreement with this finding, the CNTs functionalized with the thinnest PDA layer provided the best mechanical and thermal properties. This result confirmed that a thinner PDA layer could provide optimized interfacial interactions between the CNT@PDA and epoxy matrix and weaken the self-agglomeration of CNTs, which led to an improved effective stress and heat transfer between the CNTs and the polymer matrix.

Multi-walled carbon nanotubes (MWCNTs) were coated with silica by a sol-gel method to improve interfacial bonding and dispersion of nanotubes in the diglycidyl ether of bisphenol A (DGEBA) matrix. TEM and FE-SEM measurements showed that the silica shell was successfully coated on the surface of r-MWCNTs (as-received MWCNTs), and that the dispersion of MWCNT@SiO2 in the epoxy matrix and interfacial adhesion between MWCNTs and epoxy were improved through the silica shell formation. The effects of silica-coated multi-walled carbon nanotube (MWCNT@SiO2) addition on the curing behavior of epoxy resin, and on the physical and thermomechanical properties of epoxy composites, were studied. FT-IR measurements of different blends at different curing times indicated that the curing reaction was accelerated with the presence of MWCNTs and increased with the content of MWCNT@SiO2. DSC results confirmed that the value of activation energy decreased with the introduction of MWCNTs in the order of MWCNT@SiO2 < r-MWCNTs < epoxy. It was found that the thermal conductivity of epoxy composites were significantly enhanced by incorporation of MWCNT@SiO2, relative to composites with r-MWCNTs, while the values of the glass transition temperature slightly increased, and the high electrical resistivity of these composites was retained overall.

The water-gas shift (WGS) reaction (where carbon monoxide plus water yields dihydrogen and carbon dioxide) is an essential process for hydrogen generation and carbon monoxide removal in various energy-related chemical operations. This equilibrium-limited reaction is favored at a low working temperature. Potential application in fuel cells also requires a WGS catalyst to be highly active, stable, and energy-efficient and to match the working temperature of on-site hydrogen generation and consumption units. We synthesized layered gold (Au) clusters on a molybdenum carbide (α-MoC) substrate to create an interfacial catalyst system for the ultralow-temperature WGS reaction. Water was activated over α-MoC at 303 kelvin, whereas carbon monoxide adsorbed on adjacent Au sites was apt to react with surface hydroxyl groups formed from water splitting, leading to a high WGS activity at low temperatures.