Hydrophobic interactions Hydroxyethyl cellulose

Tanaka R, Meadows J, Williams PA, Phillips GO. Interaction of hydrophobically modified (hydroxyethyl) cellulose with various added surfactants. Macromolecules 1992 25 1304-1310. 

Entrapment within polyacrylamide beads Reaction with cyanogen bromide-treated copolymers of acrylamide and 2-hydroxyethyl methacrylate Reaction with glutaraldehyde-treated polyacrylamide and with copolymers of acrylamide and methyl methacrylate Reaction with glutaraldehyde-treated polyacrylamide beads Coating on a platinum electrode and enclosure within nylon netting Hydrophobic interaction with cellulose esters and with phenoxyacetylated-dextran and other derivatives of glass... 

U Kastner. K Hoffmann, R Donges, R Ehrler. Hydrophobic ally and cationically modified hydroxyethyl cellulose and their interactions with suifactants. Colloids Surfaces 82 279-297. 1994. 

The ability of surfactant binding is enhanced through the hydrophobic interaction between polymer hydrophobes and surfactant hydrophobes. Typical model polymers such as hydrophobically ethoxylated urethane (HEUR), ethyl hydroxyethyl cellulose (EHEC), and hydroxypropyl methyl cellulose (HPMC) have been the focus of study. 

The early attempts in this area revealed that the nonionic polymer and cationic surfactants do not interact with each other. However, in the presence of some types of ions (such as SCN or U) as counterions, a weak interaction was observed. The bulkiness of the cationic surfactant head group (compared to anionic surfactants) was the main reason for such observations (Nagarajan 1989 Witte and Engberts 1987). However, recent studies have shown that many nonionic polymers can interact and associate with cationic surfactants. Hydrophobicity has been mentioned as one of the key factors and plays an important role in the interaction between nonionic polymers and cationic surfactant. Typically, polymers with higher hydrophobicity show a better interaction (Anthony and Zana 1996 Thuresson et al. 1995,1996). Zana et al. (1992) reported that when hydroxyethyl cellulose interacts with hexadecyltrimethylammonium chloride and bromide, the CAC is less than CMC and the aggregation number of the surfactant is also less compared with the polymer-free solution. Brackman et al. (1992) observed no interaction between the nonionic polymers PEO and PVP polymers and the cationic surfactant. 

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