Hydrophilic domain adsorption

This instability can be avoided by adding a non-ionic surfactant to the surface of the latex, forming a hydrophilic layer (Triton x-405 of 30 units) on the surface of the latex [22]. In addition, this compound reduces the stacking effect by masking the hydrophobic domains (or properties) of the surface. Indeed, competition for adsorption between the ODN and the surfactant molecules can also lead to desorption. However, this effect was not observed in all reported studies, but it is in principle accessible by comparing the adsorption energies of ODN and the surfactant on the surface of the latex. 

Fig. 9. Temperature dependence of the fiequency of C3-rotation of the CH3 group around die Si-C bond (1), motion of chains outside die adsorption layer (2, points), anisotropic motion of adsorbed chain units (3) in filled PDMS containing hydrophilic Aerosil [9] the temperature-fiequency domain fm adsorption-desorption processes is shown by the dashed area (4) solid line (2) shows the temperature dependence of chain motions (a-relaxadon) in unfilled PDMS...

There have been many investigations on surfactant foams, foam films. Plateau border, foam drainage and their physical chemistry. The application of these results to protein foams is only partly possible. Proteins are macromolecules, their adsorption is coupled with a change in conformation at the gas/liquid interface which is a slow process. It takes 15 to 20 h to obtain the equilibrium surface tension. The residence time of the protein molecules in a flotation column is too short to attain the equilibrium surface tension during this time. Therefore, the transport of proteins to the interface and their adsorption at the interface are dynamical processes which are far from equilibrium. Surfactants have well-defined hydrophilic and hydrophobic domains. Thus it is relatively easy to calculate their interaction with the interface. Protein molecules have several hydrophilic and hydrophobic domains, and their interaction with the interface depends on the hydrophilic/hydrophobic character of their surface... 

The objective of functionalization of polymer surfaces is to create a surface that shows high fibronectin adsorption and, at the same time, guarantees the availability of its cell binding domains. Hydrophilic surfaces favor adsorption of fibronectin and fibronectin shows high affinity to sulfonic acid and sulfate groups [123]. This is the reason why the fimctionalization of hydrophobic polymer surfaces is carried out by SO2 plasma treatment, so that not only the hy-drophilicity is increased but oxidized sulfur groups are also introduced (Fg.22). 

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