Silane oligomers

Figure 4.31 Total energy per Si repeat unit of (a) methyl(phenyl)silane oligomer 42 with 21 Si repeat units and (b) n-hexyl(phenyl)silane oligomer 46 as a model of 43 with 31 Si repeat units as a function of the Si-Si-Si-Si dihedral angle.

The scheme of the chemical composition of the ceramic ink is visible in Fig. 11. Component A denotes the surface-modified coloring pigments, B the silane oligomers, C the Si02 nanoparticles, and D the silane monomers. 

We also mention here the dehydrocoupling of silanes which gives silane oligomers and polymers39 ... 

Silicon-backbone materials include silane oligomers, polysilanes, silicon clusters, and amorphous and crystalline silicons. These materials have been investigated independently in two different fields. Crystalline and amorphous silicon are studied in the field of solid-state physics (i), whereas polysilanes and related molecules are studied in the field of organosilicon chemistry (2). Crystalline silicon (c-Si) and amorphous hydrogenated silicon (a-Si H) are well known as two of the most useful semiconductors for electronic and optical devices. Polysilanes have been investigated for application as SiC ceramic binders (3) and photoresists (4). The methods of synthesizing... 

I have focused on methyl derivatives of nonsiloxane organosilicon backbones to achieve a useful comparison of polymer backbones. There are studies on materials with pendant groups other than methyl and backbones other than siloxane. The most useful of these studies is the direct liquid-surface-tension measurement by Feher and co-workers (96) of silane oligomers from trisilane to heptasilane, including some branched species (Table XV) (96-99). The data are useful because they answer the question of the surface activity contribution of the Si-H group. The situation with SiH-containing siloxanes... 

Table XV. Liquid Surface Tension of Silane Oligomers at 20 ...

Further experiments have been done to determine the molecular weight of silane oligomers formed on the surfaces of various fillers and the amount of silane retained after THF washing. Table 6.3 shows how the retention of silane compares with the pH of the filler slurry. Neutral pH favors retention of silane, whereas a ba-... 

In either process, the rate of adsorption is expected to be extremely slow. Hence, the addition of an alkaline catalyst greatly aids in accelerating these adsorption processes. Heat and/or time can achieve the same viscosity reduction effect, because both increased temperature and prolonged time lead to more adsorbed silanes. Very few silane oligomers are produced in this method since the hydrolyzed silane molecules do not exist in quantity at any time of treatment. Unlike the mixing of a silane pretreated filler, it is essential to consider the kinetics of silane adsorption in this type of treatment method. 

Mack, H. (2004) Silane oligomers a class of their own. Silanes and Other Coupling Agents III (ed. K.L. Mittal) VSP, Boston,... 

The concentration of silane in the primer solution during application controls the thickness of the silane coating on the surface. Poor adhesion is obtained if the silane coating is too thick. A thick, cross-linked silane oligomer is a weak layer and the bond would fail in the silane layer. Poor adhesion is also obtained if the silane coating is too thin because... 

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