title: Microscopic structure of gelatin coacervates.
abstract: Microscopic structure of simple coacervates of gelatin having concentration approximately 130 g/l were studied at 25 degrees C by atomic force microscopy (AFM), rheology, small angle neutron scattering (SANS), UV absorption and circular dichroism (CD) techniques. The behavior of viscoelastic exponents Delta' and Delta'' of storage and loss modulii (G'(omega) approximately omega Delta', G''(omega) approximately omega Delta") revealed that, Delta' = 0.25+/-0.01 and Delta'' = 0.78+/-0.1 for coacervates. The mass fractal dimension 'd(f)' for coacervate was found to be 2.27, which attributed a compact heterogeneous network structure to the coacervates. This is supported by AFM pictures. The CD and UV absorption data indicated presence of helical structures inside the coacervates phase. SANS results showed the existence of a single length scale associated with this system identified as gelatin persistence length, zeta = 27+/-2 A. These studies indicate that the coacervate phase is a low dimensional dense heterogeneous material comprised of strongly interconnected triple helices which imparts a large storage modulus to this material.
authors.affiliation: School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.forename: Biswaranjan
authors.initials: B
authors.lastname: Mohanty
authors.forename: H B
authors.initials: HB
authors.lastname: Bohidar
mesh_terms: D002942:Circular Dichroism; D004548:Elasticity; D000431:Ethanol / Q000494:pharmacology; D005780:Gelatin / Q000737:chemistry*; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D018625:Microscopy, Atomic Force; D009502:Neutrons; D009690:Nucleic Acid Conformation; D012212:Rheology; D012542:Scattering, Radiation; D013696:Temperature; D014466:Ultraviolet Rays; D014783:Viscosity
chemical_list: D046911:Macromolecular Substances; D000431:Ethanol; D005780:Gelatin