Contact angles of water droplet on as-grown Z, +X, –X, and m faces of synthetic quartz crystals with growth term of 20 and 48 days, and polished Z, +X, –X, Y, and 45° cut faces of synthetic quartz crystal we...Contact angles of water droplet on as-grown Z, +X, –X, and m faces of synthetic quartz crystals with growth term of 20 and 48 days, and polished Z, +X, –X, Y, and 45° cut faces of synthetic quartz crystal were observed. The average of the contact angles on as-grown Z, +X, and –X faces increased with the growth term, and they were larger than that on polished Z, +X, and –X faces. On the other hand, the average of the contact angles of water on m face decreased with the growth term, and they were smaller than that on polished Y cut face. Growth rate of the faces of synthetic crystals was measured and the order of growth rate was, m < –X < +X < Z. Specific surface free energy (SSFE) was calculated using Neumann’s equation. The SSFE of polished face was in the order of, m < –X < +X < Z, which corresponds to the order of the growth rate. The SSFE was larger for the face with larger growth rate.展开更多
A mercury-free solid electrode system for the electrochemical generation of O ·- 2 was described. The effects of pH, the amount of the surfactant and electrode materials on the reduction of O 2 were investigated....A mercury-free solid electrode system for the electrochemical generation of O ·- 2 was described. The effects of pH, the amount of the surfactant and electrode materials on the reduction of O 2 were investigated. The electrogeneration of O ·- 2 was only obtained at the Pt electrode in this medium system. The different electrochemical behaviour of O 2 at Pt electrode and Au electrode were explained in terms of the different adsorptions of DSAB, which was confirmed by quartz crystal microbalance(QCM). The frequency responses for the reduction of O 2 at Pt electrode and Au electrodes were compared by electrochemical quartz crystal microbalance(EQCM), suggesting that the electrogenerated O ·- 2 was adsorbed on the surface of the Pt electrode. The one-electron reduction of oxygen in this system was also confirmed by using chronocoulometry. The scavenging activities of two kinds of antioxidants(ascorbic acid and cysteine) were examined and compared.展开更多
文摘Contact angles of water droplet on as-grown Z, +X, –X, and m faces of synthetic quartz crystals with growth term of 20 and 48 days, and polished Z, +X, –X, Y, and 45° cut faces of synthetic quartz crystal were observed. The average of the contact angles on as-grown Z, +X, and –X faces increased with the growth term, and they were larger than that on polished Z, +X, and –X faces. On the other hand, the average of the contact angles of water on m face decreased with the growth term, and they were smaller than that on polished Y cut face. Growth rate of the faces of synthetic crystals was measured and the order of growth rate was, m < –X < +X < Z. Specific surface free energy (SSFE) was calculated using Neumann’s equation. The SSFE of polished face was in the order of, m < –X < +X < Z, which corresponds to the order of the growth rate. The SSFE was larger for the face with larger growth rate.
文摘A mercury-free solid electrode system for the electrochemical generation of O ·- 2 was described. The effects of pH, the amount of the surfactant and electrode materials on the reduction of O 2 were investigated. The electrogeneration of O ·- 2 was only obtained at the Pt electrode in this medium system. The different electrochemical behaviour of O 2 at Pt electrode and Au electrode were explained in terms of the different adsorptions of DSAB, which was confirmed by quartz crystal microbalance(QCM). The frequency responses for the reduction of O 2 at Pt electrode and Au electrodes were compared by electrochemical quartz crystal microbalance(EQCM), suggesting that the electrogenerated O ·- 2 was adsorbed on the surface of the Pt electrode. The one-electron reduction of oxygen in this system was also confirmed by using chronocoulometry. The scavenging activities of two kinds of antioxidants(ascorbic acid and cysteine) were examined and compared.
