Silica and Polydimethylsiloxane

Polyorganosiloxanes, the so-called silicones, whose general formula is R -(SiOR2)n-R, are a family of polymer materials with unique and interesting properties. Silicone polymers have the alternating -Si-O- type structure as part of their backbone chain and although silicon is in the same group as carbon in the periodic table, it has quite a different chemistry. Various 

Various PDMS materials are obtained through synthesis and hydrolysis of chlorosilanes, then polycondensation, according to the following schema  

The adsorption kinetics is consequently an issue of industrial importance with silica/silicone systems and was consequently thoroughly investigated. Cohen-Addad et al. studied the time dependence of the adsorption of siloxane chains on silica aggregates and proposed the following empirical model  

Equation 6.1 is essentially an empirical model, likely selected for its convenience in fitting experimental data, using a linear algorithm for instance the least square method. It is worth noting that considering the variation of 

Adsorption kinetics of polydimethylsiloxane on silica particles. (Experimental data from L. Dujourdy, PhD Thesis, University of Grenoble, France, 1996 nonlinear fitting of Equation 6.2.) 

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