Organically modified montimorillonite nanoclay was added to the epoxy and E-glass-epoxy composites. The influence of nanoclay content (varied between 0 to 5wt %) on the relative crosslink density and the fracture toughness of the epoxy matrix was studied. Differential scanning calorimetry (DSC) indicated that the amino functional groups present on the nanoclay react with the epoxy matrix to increase the crosslink density of about 13 and 18% at 3 and 5wt% addition, respectively. The toughness of the epoxy composites increased by 25% at 3wt% addition of nanoclay, whereas, it decreases at 5wt%. Flexural strength and tensile strength of the E-glass-epoxy composites were found to increase by 12% and 11% respectively at 3wt% addition of nanoclay, while at 5wt% addition these properties decreased due to the matrix embrittlement. Interestingly matrix embrittlement is found to be beneficial in increasing the impact resistance due to spallation of embrittled matrix that ensures the dissipation of the impact energy. 5wt% nanoclay addition increases the impact strength by 29% and reduces the back face bulge of composite by 31%. These results may lead to the design and realization of glass-epoxy composites with better impact strength.design and realization of glass-epoxy composites with better impact strength.
This work was aimed to design efficient catalysts for N 2 O decomposition at low temperatures. Cobalt oxide (Co 3 O 4) was prepared by hydrothermal, precipitation and combustion methods and tested for N 2 O decomposition. It was found that the catalysts prepared by solution combustion synthesis were most active for this reaction. Subsequently, a series of ceria (CeO 2) supported Co 3 O 4 catalysts (xCeCo) were prepared by solution combustion method and used them for N 2 O decomposition. All the catalysts were characterized by analytical methods like XRD, TEM, BET, XPS, UV-Vis, Raman and H 2-TPR. It was found that 10 and 20 wt..% loading of CeO 2 on Co 3 O 4 promoted the activity of Co 3 O 4 towards N 2 O decomposition, whereas, higher loading of CeO 2 reduced the activity. Typical results indicated that addition of CeO 2 increases the surface area of Co 3 O 4 , and improves the reduction of Co 3+ to Co 2+ by facilitating the desorption of adsorbed oxygen species, which is the rate-determining step for the N 2 O decomposition over Co 3 O 4 spinel catalysts. Optimal CeO 2 loading can increase both dispersion and surface area of Co 3 O 4 catalysts and weaken the CoO bond strength to promote N 2 O decomposition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.