Biopolymers stability

The layer-by-layer method enables the fabrication of multiple-layer polyelectrolyte capsules and emulsions. It consists of the spontaneous deposition of biopolymer stabilizing layers at the interface of particles or emulsion droplets, driven by the electrostatic attraction between the templating interface and the forming monolayers. In particular, the spontaneous deposition of a first layer of... 

Proteins are biopolymers formed by one or more continuous chains of covalently linked amino acids. Hydrogen bonds between non-adjacent amino acids stabilize the so-called elements of secondary structure, a-helices and / —sheets. A number of secondary structure elements then assemble to form a compact unit with a specific fold, a so-called domain. Experience has shown that a number of folds seem to be preferred, maybe because they are especially suited to perform biological protein function. A complete protein may consist of one or more domains. 

Stabilization of Ordered Structures Qf Biopolymers by Solvation Effects... 

Fig. 7. Besides direct interactions between functional groups of the biopolymer molecule itself there are also various kinds of interactions with water molecules. These hydrophilic and hydrophobic interactions are essential for stabilizing the native conformation of biopolymers. In the last few years some progress was made in elucidating the hydration of these molecules.

Covalent bridging of biopolymers is one of the widely occurring prindples in nature for increasing the stability of the tertiary structure, for example the disulfide bridges in keratin and ribonuclease. 

GA is a natural biopolymer with wide industrial use as a stabilizer, a thickener, an emulsifier and in additive encapsulation not only in food industry but also in textiles, ceramics, lithography, cosmetic and pharmaceutical industry (Verbeken et al., 2003). 

PLA/PCL-OMMT nano-composites were prepared effectively using fatty amides as clay modifier. The nano-composites shows increasing mechanical properties and thermal stability (Hoidy et al, 2010c). New biopolymer nano-composites were prepared by treatment of epoxidized soybean oil and palm oil, respectively plasticized PLA modified MMT with fatty nitrogen compounds. The XRD and TEM results confirmed the production of nanocomposites. The novelty of these studies is use of fatty nitrogen compoimds which reduces the dependence on petroleum-based surfactants (Al-Mulla et al., 2011 Al-Mulla et ah, 2011 Al- Mulla et ah, 2010c). 

The stability of a colloid such as gelatin in water is determined by the electric charge and hydration. The addition of large amounts of electrolytes to colloids (biopolymers) causes... 

Sanborn, T., Wu, C., Zuckermann, R., and Barron, A. Extreme stability of helices formed by water-soluble poly-7M-sub-stituted glycines (polypeptoids) with alpha-chiral side chains. Biopolymers 2002, 63, 12-20. 

A fluid loss additive for hard brine environments has been developed [1685], which consists of hydrocarbon, an anionic surfactant, an alcohol, a sulfonated asphalt, a biopolymer, and optionally an organophilic clay, a copolymer of N-vinyl-2-pyrrolidone and sodium-2-acrylamido-2-methylpropane sulfonate. Methylene-bis-acrylamide can be used as a crosslinker [1398]. Crosslinking imparts thermal stability and resistance to alkaline hydrolysis. 

Vila JA, Ripoll DR, Scheraga HA (2001) Influence of lysine content and pH on the stability of alanine-based copolypeptides. Biopolymers 58 235—246. 

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