The electronic structure change in the valence band of molybdenum (110) during argon ion bombardment is studied. The UPS measurements using synchrotron radiation show that argon ion bombardment induces a reduction in intensity of the peak at 4.10 eV below Fermi energy and a decrease in the work function. This peak reduction is explained in terms of substitution of a vacancy for a molybdenum atom. The decrease in the work function also suggests that vacancies are being created in the surface region due to argon ion bombardment.
Silica sol, which has heat-resistant and nonflammable properties, is one of the important coating materials which gives glossy and antisoiled film on the surface of building materials, but the film-forming properties of silica sols are not satisfactory. In order to improve the film-forming properties, it is effective to modify the silica sols with synthetic resin emulsion. Thus we studied the influence of the type of synthetic resin emulsion, the type of silica sol, the mixing ratio of the resin to the sol, and the particle size of the silica sol on such physical properties of the coatings as surface gloss, antisoil, and durability. Consequently, though silica sol itself did not have good film-forming properties, the properties were improved by adding more than 10 parts by weight of synthetic resin emulsion to 100 parts by weight of silica sol as a solid, and more than 20 parts of resin showed excellent film-forming properties. Meanwhile, coating which showed good surface gloss, antisoil, and durability were obtained in the range of from 30 to 100 parts of resin. Coatings surface which were prepared from silica sols modified with synthetic resin emulsion maintained their good properties after exposure to various kinds of durable tests for a long time.