Surface properties: silicones

Binder for various multi-component and hybrid coatings (abrasives, powder, fillers) with silicone surface properties mentioned above... 

A chemical property of silicones is the possibility of building reactivity on the polymer [1,32,33]. This allows the building of cured silicone networks of controlled molecular architectures with specific adhesion properties while maintaining the inherent physical properties of the PDMS chains. The combination of the unique bulk characteristics of the silicone networks, the surface properties of the PDMS segments, and the specificity and controllability of the reactive groups, produces unique materials useful as adhesives, protective encapsulants, coatings and sealants. 

Silicon wafer has been extensively used in the semiconductor industry. CMP of silicon is one of the key technologies to obtain a smooth, defect-free, and high reflecting silicon surfaces in microelectronic device patterning. Silicon surface qualities have a direct effect on physical properties, such as breakdown point, interface state, and minority carrier lifetime, etc. Cook et al. [54] considered the chemical processes involved in the polishing of glass and extended it to the polishing of silicon wafer. They presented the chemical process which occurs by the interaction of the silicon layer and the... 

Si-C formation technique with hydrogen-terminated silicon substrates can also be used as the covalent attachment of nanomaterials onto silicon surface. The possibility of assembling nanomaterials in order is strongly desired in order to enable efficient utilization of their unique nano-sized properties. Ordered arranging and position controlling of nanomaterials on solid substrates especially on silicon surface have been intensively studied [10]. In this manuscript, the nanoparticle immobilization by thermal Si-C formation will be discussed [11]. 

In the category of silicone coatings used for surface modification of the specific substrates, functional silicone fluids are often used, which can selectively interact with the chemical groups of the substrate, thus modifying its surface properties. The use of functional silicones in the textile industry has been discussed in a number of recent publications.5 421 422 The use of different types of high-performace silicone-coated textiles, which include elastomers and resins, has recently been reviewed.423 The use of functional silicones in personal-care products, for example, in shampoos and hair conditioners, mentioned before,381 provides another well-known example. 

Owen, M. J. Surface Properties and Applications. In Silicon-Containing Polymers. The Science and Technology of Their Synthesis and Applications Jones, R. G., Ando, W., Chojnowski, J., Eds. Kluwer Dordrecht, 2000 pp 213-231. 

She, H. Chaudhury, M. K. Owen, M. J. Surface Properties of Thin Film Poly(dimethylsiloxane). In Silicones and Silicone-Modified Materials Clarson, S. J., Fitzgerald, J. J., Owen, M. J., Smith, S. D., Eds. ACS Symposium Series 729 American Chemical Society Washington, DC, 2000 pp 322-331. 

While these potentials have been successful in modeling dynamic processes on silicon surfaces, the many-body expansion as applied in this case suffers from several drawbacks. Because all of the three potentials above have been fit to properties of the crystalline silicon soUd, they implicitly assume tetrahedral bonding. Atoms on the surface of silicon are known to exhibit nontetrahedral hybridizations, and so the results for surfaces are at best uncertain. Also, none of these potentials reproduce accurately the properties of the Sij diatomic molecule. This again inhibits a complete description of surface reactions. 

This discussion has emphasized the fundamental differences between finite (whether small or large) and fully extended systems. An energy functional which describes, for example, 1 cm of silicon or lead, contains a great deal of information about its surface properties as well as its bulk properties. However, all such surface information disappears from the functional when the thermodynamic limit is taken. I must emphasize that this process is irreversible Information on physical quantities which are sensitive to the delicate correlations in the boundary regions cannot be found in energy functionals of the corresponding extended system. This is another example of the importance of the global boundary conditions and the related universality subclasses. 

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