Interfacial layers bound polymers

Since the largest ion fragments are trimers, the presence of an interfacial layer of high crosslink density at the silane-glass interface is indicated. It is difficult to differentiate between a strongly bound polymer or a thick layer of highly crosslinked silane, but the XPS results [ 15] strongly indicate the presence of the former. 

In proton T2 experiments conducted by Litvinov [18] a strong dynamic heterogeneity in the fraction of EPDM bound to carbon black could also be detected an immobilised EPDM layer covering the carbon black surfaces and a mobile EPDM part outside of this interfacial layer. In dynamic-mechanical experiments by Haidar [19], it was found that the polymer layer on the filler surface had glass-like mechanical properties. 

An enhancement in may be due to nonuniform electrostatic field in a relatively thick interfacial layer containing tails and segments of adsorbed polymer molecules. The amount of the WBW in this layer is larger than that around pure silica particles (Table 5.10), as well as the thickness of the interfacial layer perturbed by PVP+dissolved ions and silica particles in comparison with that for the initial silica suspension. This leads to an increase in the surface area in contact with unfrozen water (Table 5.10, The polymer molecules set a significant portion (all PVP molecules are bound to the silica surface) in this layer. However, the sum is the same at 0.3 wt% PVP. The... 

In summary, we suggest that both the degree of interfacial fluidity and the polymer layer thickness play key roles in determining the lubrication performance of surface-bound brushlike polymers in general and of PLL-g-PEG in particular. Both solvent quality and the nature of the counterface can influence these parameters. 

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