Hydroxyethyl cellulose Interface

Dynamic Behavior of Hydrophobically Modified Hydroxyethyl Celluloses at Liquid/Air and Liquid/Liquid Interfaces... 

The rheological properties of a fluid interface may be characterized by four parameters surface shear viscosity and elasticity, and surface dilational viscosity and elasticity. When polymer monolayers are present at such interfaces, viscoelastic behavior has been observed (1,2), but theoretical progress has been slow. The adsorption of amphiphilic polymers at the interface in liquid emulsions stabilizes the particles mainly through osmotic pressure developed upon close approach. This has become known as steric stabilization (3,4.5). In this paper, the dynamic behavior of amphiphilic, hydrophobically modified hydroxyethyl celluloses (HM-HEC), was studied. In previous studies HM-HEC s were found to greatly reduce liquid/liquid interfacial tensions even at very low polymer concentrations, and were extremely effective emulsifiers for organic liquids in water (6). 

Nahringbauer, I. Dynamic surface tension of aqueous polymer solutions, I Ethyl(hydroxyethyl)cellulose (BERMOCOLL cst-103), /. Colloid Interface Sci., 176, 328,1995. 

Fig. 1.21 Photograph of a polystyrene latex dispersion (16 vol%) in 10 mM NaCl at pH 7 with (as indicated in wt%) added hydroxyethyl cellulose (HEC) studied by Faers and Luckham [145]. In the lower photograph the tubes are tilted demonstrating the difference between rigid colloidal solid-liquid and fluid colloidal gas-liquid interfaces for the three-phase coexistence at 0.3 wt% HEC. Reprinted from M. A. Faers and P.F. Euckham, Langmuir, 13 2922, Copyright 1997, with permission from the American Chemical Society and the authors...

Mehra has used Plextol B-500, an acrylic methacrylate copolymer in dilute solution along with a thickener. He first used hydroxyethyl cellulose to gel the adhesive to keep it at the lamina interface, later he used microspheres to apply the film as a slurry. These lining methods were easily activated in the absence elevated temperatures and only slight pressures. Hacke has used a thickener based on methacryl acid in small concentrations with plextol D360 as another adhesive system for a low pressure activated adhesive [9]. 

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