Mechanics of Glass Processes

Thus, we considered a number of examples of application of the sensor technique in experiments on heterogeneous recombination of active particles, pyrolysis and photolysis of chemical compounds in gas phase and on the surface of solids, such as oxides of metals and glasses. The above examples prove that, in a number of cases, compact detectors of free atoms and radicals allow one to reveal essential elements of the mechanisms of the processes under consideration. Moreover, this technique provides new experimental data, which cannot be obtained by other methods. Sensors can be used for investigations in both gas phase and adsorbed layers. This technique can also be used for studying several types of active particles. It allows one to determine specific features of distribution of the active particles along the reaction vessel. The above experiments demonstrate inhomogeneity of the reaction mixture for the specified processes and, consequently, inhomogeneity of the... 

It has been known for some time that hexatrienes can be formed by reaction of excited benzene molecules with solvent in a frozen glass (262-264). Some details of the mechanism of this process have been deduced by Simons and Smith (90). They propose that intermolecular vibronic interaction with solvent is a necessary but not sufficient requirement for production of hexatrienes in viscous media. The reaction is associated with radiationless decay of the triplet state rather than a bimole-cular reaction of triplet benzene with neighboring solvent molecules. Since radiationless decay constitutes intersystem crossing, the product of the reaction is also in the ground state. It is stressed by the authors that hexatrienes are not produced in fluid media or by nonphosphorescent benzene derivatives in which there is a rapid competing decay of the triplet state. 

Figure 15.9 shows the effect of glass fiber on the rate of conversion of novolac resin.The addition of glass fiber decreases rate of curing and degree of conversion. The chemical mechanism of this process is not discussed. 

The present report is devoted to recent studies on anionic and cationic polymerizations in various glasses. The new results give better insight into the mechanism of these processes. 

Percolation of the oxygen gas into the separator is facilitated by more intimate contact between the glass mat surface and the surface of the positive plate. This is achieved by applying compression to the active block. There are two possible mechanisms of this process ... 

Finally, the mechanism of the process can be reduced to the dissolution of fly ash glass or ciystalline zeohte, in the case of natural pozzolana. There is an opinion that the pozzolanas composed of zeolites are more reactive than the vitreous ones [27], This can be related to the high porosity of zeolites and their ion exchange ability [41], Therefore the bonding of calcium ions occurs veiy quickly and pozzolana is transformed into the alumina-siUca gel. 

The mechanism of the process occurring at the glass I solution interface continued to intrigue researchers. In a further study of this problem, Horovitz ( 12.) and Schiller (12), out of Horovitz s laboratory, extended Haber s theory. In this extension they considered... 

The analyas of the data obtained for a number of sterns, containing both inorganic and polymeric fillers, shows that the average time of relaxation of the process of isothermic contraction t v increases in the presence of hard particles. However, from the point of view of understanding the mechanism of the processes which occur in the interface, it is mote cmrect to compare tte relaxation time at corresponding temperatures equidistant from the glass transient t nperature, rather than at equal temperatures. 

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