Hydrophilic-hydrophobic surface

P. O. Kuzema, Properties of chemically modified high-disperse silicas with hydrophilic-hydrophobic surface (PhD Thesis, Kyiv, 2004). 

The scope of the chapter will include an introduction to the technique of neutron reflectometry, and how it is applied to the study of surfactant adsorption at the planar solid-solution interface, to obtain adsorbed amounts and details of the structure of the adsorbed layer. The advantages and limitations of the technique will be put in the context of other complementary surface techniques. Recent results on the adsorption of a range of anionic, cationic and nonionic surfactants, and surfactant mixtures onto hydrophilic, hydrophobic surfaces, and surfaces with specifically tailored functionality will be described. Where applicable, direct comparison with the results from complementary techniques will be made and discussed. 

Dekany, I. and Nagy, L. G. Immersional wetting and adsorption displacement on hydrophilic/hydrophobic surfaces.. Colloid Interface Sci. 147(1) 119—28, 1991. 

We are combining the selective deposition of polypyrrole and polyaniline on hydrophilic/hydrophobic surfaces as described in the preceeding section with the recent microcontact printing technique (18-20) to produce patterned conducting polymer films which we have demonstrated can be used in PDLC display-type devices. 

Table 6.15 Hydrophilic/hydrophobic surface characteristics of various commerciai NF membranes based on contact angle...

An example of plasma polymerization is acrylic acid coating of PDMS. The polymerized coatings yielded hydrophilic or patterned hydrophilic/ hydrophobic surfaces that were quite stable. These materials were useful in PDMS microchannels in lab-on-a-chip devices or in soft microlithography. Maleic anhydride has also been used in these polymerizations. Photons have also been used to modify surfaces. ... 

In the case of protein or mineral components of bovine bone tissue, the influence of solvents on bound water differs from that for human bone tissue (Tables 7.15 and 7.17 and Figure 7.68). Addition of less polar solvents gives smaller changes in the Ys, and AG values. These results can be explained by a lower heterogeneity of BBl and BB2 samples than native one, i.e., model samples BBl and BB2 have less mosaic (hydrophilic/hydrophobic) surfaces than native bone tissue. WAW is more strongly bound and freezes at temperatures considerably lower than the freezing point of the major fraction of SAW. 

This situation is, of course, far from satisfactory. We therefore turned to atomistic simulations of all-atom (AA) poly(styrene sulfonate) (PSS) and poly(diallyldi-methylammonium) (PDADMA) systems [160]. The polymers had a low degree of polymerization which was 12 at most. Our main target was to investigate some properties such as the dielectric constant and water structure that cannot be addressed using CG models. Moreover, in a second recent effort, we looked at PSS monolayer simulations for hydrophilic/hydrophobic surfaces and different surface charge [161]. 

The adsorption of surfactants on solids is affected by the surface properties (hydrophilicity/hydrophobicity, surface charge) and by the surfactant properties (ionic/non-ionic, CMC, HLB). Figure 3.9 illustrates the possible configurations of non-ionic surfactants on hydrophobic (A) and on hydrophilic (B) solid surfaces as well as those of cationic surfactants on negatively charged oxide layers (C). The surface concentrations increases successively from row I (ideal gas) to row IV or V (saturated surface). The picture reveals a broad variety including monolayers. 

Microcalorimetric Control of Liquid Sorption on Hydrophilic/Hydrophobic Surfaces in Nonaqueous Dispersions... 

Chapter 10, by Dekany (Hungary), describes the microcalorimetric control of liquid sorption on hydrophilic/hydrophobic surfaces in nonaqueous dispersions. 

LIA 99a] Liang L., Feng X., Liu J. et al., Preparation of composite-crosslinked poly(N-isopropylaciylamide) gel layer and characteristics of reverse hydrophilic-hydrophobic surface . Journal of Applied Polymer Science, vol. 72, pp. 1-11, 1999. 

Motion of Drops at Boundary of Hydrophilic-Hydrophobic Surface... 

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