Cobalt Molybdate Incorporated Thermoset Composites: Preparation and Characterization

Piezo-chromic oxides are able to mark pressure or strain by a drastic color change. In this paper, CoMoO4 molybdate compound and related thermoset composites were prepared in lab. The distribution of CoMoO4 oxide in the thermoset matrix was first investigated via SEM. Moreover, the effects on the thermal and mechanical properties with the addition of CoMoO4 oxide were further analyzed. The piezo-chromic characteristic for CoMoO4 incorporated thermoset composites were verified with compression test. The color change can be clear visualized at a strain level close to the yield point of the composite blends. This study has the potential to open new directions to piezo-chromic polymeric materials as early damage detector.

Insights into the Antimicrobial Activity of Hydrated Cobaltmolybdate Doped with Copper

Molybdates are biocidal materials that can be useful in coating surfaces that are susceptible to contamination and the spread of microorganisms. The aim of this work was to investigate the effects of copper doping of hydrated cobalt molybdate, synthesized by the co-precipitation method, on its antibacterial activity and to elucidate the structural and morphological changes caused by the dopant in the material. The synthesized materials were characterized by PXRD, Fourier Transformed Infrared (FTIR), thermogravimetric analysis/differential scanning calorimetry (TG/DSC), and SEM-Energy Dispersive Spectroscopy (SEM-EDS). The antibacterial response of the materials was verified using the Minimum Inhibitory Concentration (MIC) employing the broth microdilution method. The size of the CoMoO4·1.03H2O microparticles gradually increased as the percentage of copper increased, decreasing the energy that is needed to promote the transition from the hydrated to the beta phase and changing the color of material. CoMoO4·1.03H2O obtained better bactericidal performance against the tested strains of Staphylococcus aureus (gram-positive) than Escherichia coli (gram-negative). However, an interesting point was that the use of copper as a doping agent for hydrated cobalt molybdate caused an increase of MIC value in the presence of E. coli and S. aureus strains. The study demonstrates the need for caution in the use of copper as a doping material in biocidal matrices, such as cobalt molybdate.

Incomplete amorphous phosphorization on the surface of crystalline cobalt molybdate to accelerate hydrogen evolution

The development of non-noble metal-based electrocatalysts is of great significance to the wide application of electrocatalytic hydrogen production. However, construction of a highly active surface layer with synergistic sites toward...