Using a scanning tunneling microscope (STM), the concerted dynamics of H-bonds is visualized in real space. The STM manipulation of individual water molecules enables engineering of individual H-bonds, providing model systems to explore the H-atom transfer reaction on a metal surface. The relay reaction, which is the key mechanism in proton transfer in diverse systems, was directly observed for H2O-(OH)n(n = 2-4) complexes on Cu(110). The reaction was investigated as a function of transfer distance and bias voltage, and the mechanism of the electron-induced relay reaction was discussed.
We have recently intensively studied the dissociation of individual water molecules on ultrathin MgO film grown on Ag(100) substrate at the single-molecule level, by means of both scanning tunneling microscopy experiment and density functional theory calculations. We have found clear evidence for that the chemical reactivity of ultrathin MgO film can be controlled by the film thickness, in which the interfacial interaction between oxide and metal substrate plays an important role in determining chemical reactivity. In this short review, we briefly discuss the role of the ultrathin insulating film in water dissociation induced by vibrationally excited state using inelastic tunneling electrons, which is crucial to selectively achieve two kinds of dissociation path, as well as underlying thickness dependence of chemical reactivity.
Adsorbed proteins initiate the undesirable phenomena like blood coagulation and immune response, and lead to the negative effects on human body and function of biodevices. Thus, the suppression of protein adsorption is essential property for biomaterials. Therefore, interfacial water molecules may play a key role on protein adsorption. In this study, various types of surface; hydrophobic, hydrophilic, anionic, cationic and zeitterionic were prepared by high-density polymer brush having different molecular structure. The amount of adsorbed negatively and positively charged protein was analyzed by quartz crystal microbalance (QCM) method to investigate the protein adsorption on polymer brush surfaces quantitatively. Structure of interfacial water at the interface between polymer brush and water media was investigated using sum-frequency generation (SFG) spectroscopy. From the quantitative comparison with protein adsorption and structure of interfacial water molecule of each polymer brush, it is concluded that the interfacial water molecules, which form strong hydrogen bonding is a strong relation to the suppression of protein adsorption.
Supercritical water, which forms a homogeneous phase including organic compounds, offers an environmentally benign reaction space for producing organic-inorganic hybrid materials. Supercritical hydrothermal synthesis enables the surface modification of metal oxide nanoparticles using organic compounds. Such organic-inorganic hybrid materials provide trade-off functions such as high thermal conductivity and electrical resistance. The surface modification also affects exposed surfaces and catalytic activity of nanoparticles.
The definition, property, application fields and purification facilities of ultra pure water are overviewed with the recent achievements in the technologies of water recycling and reductions in chemical consumption at first. Then the ion adsorption filter for removing ppt level of ionic impurities from ultra pure water, and the functionalized ultra pure water for precision cleaning in the fields of semiconductor and flat panel displays are described as the recent achievements in ultra pure water technology.
Polarization tool as ellipsometry is a classic but still new technology. It is used in various fields : from materials science, such as the newest nanotechnology and optical function material, to biotechnology in recent years. It has been developing into the new areas, called polarization science and polarization technology. This paper reviews a measurement method for spectroscopic Mueller matrix such as a dual rotating retarder type polarimeter, a liquid crystal phase modulation type polarimeter, and a channeled spectrum polarimeter. In addition, the important analysis is introduced for equipment calibration and a decomposition method from obtained Mueller matrix.