Mechanochemical Considerations on the Maximal Numbers of Radicals Generated in Binary Powders of Glycolic Acid and Silica-Alumina

The number of radicals generated in a binary powder of glycolic acid and silica-alumina was determined by means of electron spin resonance (ESR) spectroscopy. The maximal number of spins/g and the duration of the maximal number of spins/g were dependent on the calcination temperature of silica-alumina, on conditions of storage such as atmosphere or temperature of storage, and on the particle size of silica-alumina. Each of the above values was found to be influenced significantly by mechanical force induced by shaking or compressing. Techniques for decreasing the number of radicals induced by mechanical force are discussed.