Surfactants from polysaccharides

Similarly, naturally derived surfactants extracted from fermentation broths or prepared by partial hydrolysis of natural extracts can contain polysaccharides, proteins, and phospholipids. For example, rhamnolipids and sophorolipids have unique structural features that cause them to deposit on chemically similar surfaces and modify surface energy even at very low concentrations. Clearly, the emergence of biotechnology in the twenty-first century will drive the development of new surfactants from microbial fermentation, and improve the commercial viability of known surfactants from such processes. 

Use of High Viscosity Oii Recently Weiss et al. (2005) investigated the possibility of using a semicrystalline oil phase in W/O/gel to control the release of encapsulated hydrophilic compounds from polysaccharide gels with multiple emulsions. Various lipid phases prevent the diffusion of water/surfactant/ active material from the inner phase and also gelation of the oily or aqueous phase. For example, MCT-oil and various vegetable fats were investigated for... 

Oil-field chemistry has undergone major changes since the publication of earlier books on this subject Enhanced oil recovery research has shifted from processes in which surfactants and polymers are the primary promoters of increased oil production to processes in which surfactants are additives to improve the incremental oil recovery provided by steam and miscible gas injection fluids. Improved and more cost-effective cross-linked polymer systems have resulted from a better understanding of chemical cross-links in polysaccharides and of the rheological behavior of cross-linked fluids. The thrust of completion and hydraulic fracturing chemical research has shifted somewhat from systems designed for ever deeper, hotter formations to chemicals, particularly polymers, that exhibit improved cost effectiveness at more moderate reservoir conditions. 

Sample preparation used to extract proteins from cells prior to analysis is an important step that can have an effect on the accuracy and reproducibility of the results. Proteins isolated from bacterial cells will have co-extracted contaminants such as lipids, polysaccharides, and nucleic acids. In addition various organic salts, buffers, detergents, surfactants, and preservatives may have been added to aid in protein extraction or to retain enzymatic or biological activity of the proteins. The presence of these extraneous materials can significantly impede or affect the reproducibility of analysis if they are not removed prior to analysis. 

Figure 6.10 Effect of CITREM on the molecular and thermodynamic parameters of maltodextrin SA-2 (DE = 2) in aqueous medium (phosphate buffer, pH = 7.2, ionic strength = 0.05 M 20 °C) (a) weight average molar mass, Mw (b) radius of gyration, Ra (c) structure sensitive parameter, p, characterizing die architecture of maltodextrin associates (d) second virial coefficient, A2 or A2, on the basis of the weight ( ) and molal (A) scales, respectively. The parameter R is defined as the molar ratio of surfactant to glucose monomer units in the polysaccharide. The indicated cmc value refers to the cmc of the pure CITREM solution. Reproduced from Anokhina et al. (2007) with permission.

Figure 8.15 Cartoon showing how proteins, polysaccharides and surfactants (emulsifiers) might be distributed at the triglyceride-water interface. Inter-facial complexation in vivo between adsorbed protein and charged polysaccharide in the gastrointestinal tract could affect digestion of protein and fat by forming structures that inhibit the accessibility and activity of enzymes (proteases and lipases). Reproduced from Dickinson (2008) with permission.

In this review, we addressed the synthesis of well-defined monodimensional sugar-grafted polysiloxanes. For this reason, we excluded from this paper the synthesis of silicones (poly)-glycosides as surfactants, obtained by glycosylation of hydroxyl-terminated polysiloxanes and the preparation of polysaccharide-silicone adducts. Both are essentially described in patents, from which straighforward data concerning the sttucture of the products and the outcome of the reactions are difficult to extract. For silicone glycosides, some descriptions can be found, only in patents, for example in US 5,428,142 [2]. They are usually prepared by a Fischer... 

Because the micellar interior is far from being rigid, a solubilized substrate is relatively mobile. Like micelle formation, solubilization is a dynamic equilibrium process. Representative recent examples are the solubilization of benzene, naphthalene, anthracene, and pyrene in aqueous solution by the addition of 1-dodecanesulfonic acid [391], the solubilization of fullerene Ceo in aqueous solutions of the non-ionic surfactant Triton X-100 [392], and the solubilization of a cholesteryl-group bearing pullulane (a hydrophobized polysaccharide) [393]. 

Most UF membranes are made from polymeric materials, such as, polysulfone, polypropylene, nylon 6, PTFE, polyvinyl chloride, and acryhc copolymer. Inorganic materials such as ceramics, carbon-based membranes, and zirconia, have been commercialized by several vendors. The important characteristics for membrane materials are porosity, morphology, surface properties, mechanical strength, and chemical resistance. The membrane is tested with dilute solutions of well-characterized macromolecules, such as proteins, polysaccharides, and surfactants of known molecular weight and size, to determine the MWCO. 

Pentose-based surfactants have also been obtained through Pd-catalyzed oligomerization of butadiene [27-29]. This aspect is developed in Palladium-catalyzed telomerization of butadiene with polyols from mono to polysaccharides devoted to this type of products. 

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