MECHANISMS OF INCIPIENT CHEMICAL REACTION BETWEEN CA(OH)(2) AND SIO2 UNDER MODERATE MECHANICAL STRESSING .2. EXAMINATION OF A RADICAL MECHANISM BY AN EPR STUDY

摘要

An EPR spectroscopy was examined in detail in order to elucidate the role of mechanically induced radicals on the incipient mechanochemical reaction between Ca(OH)(2) and SiO2. The specific radical species found on separately milled Ca(OH)2 and SiO2 disappeared in the case of mixed milling. O- radicals on Ca(OH)(2) and E'centers on the SiO2 surface reacted during milling, leading to a precursor of complex oxide with Si-O-Ca bonding. Relative contribution of radical mechanism was compared with those of electron pairs to the complex formation of Si-O-Ca under mechanical stressing. (C) 1996 Academic Press, Inc. [References: 28]