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Phase Separation Behavior (phase + separation_behavior)

Distribution by Scientific Domains

Polymers and Materials Science	50%
Chemistry	50%

Selected Abstracts

Characterization of Phase Separation Behavior, Emulsion Stability, Rheology, and Microstructure of Egg White,Polysaccharide Mixtures

JOURNAL OF FOOD SCIENCE, Issue 6 2009
E. Alben Erçelebi
ABSTRACT:, Phase separation behavior of egg white-pectin/guar gum mixtures was investigated. These systems led to phase separation arisen by either depletion flocculation or thermodynamic incompatibility. The influence of polysaccharides on the emulsifying activity index (EAI), emulsifying stability index (ESI), creaming stability, microstructure, and rheological properties was also studied at different polysaccharide concentrations (0% to 0.5%, [w/v]). Increasing pectin and guar gum concentration from 0.01% to 0.5% significantly improved EAI by 51% and 25%, respectively. The highest ESI and EAI values were obtained in the presence of 0.5% (w/v) pectin/guar gum. Microscopic images showed that emulsions containing polysaccharides had small droplets as compared to that of emulsions without polysaccharides. The addition of polysaccharides improved emulsion stability against creaming. Egg white-stabilized emulsions with and without polysaccharides reflect the pseudoplastic behavior with,n,< 1.0. Polysaccharides, especially at high concentrations, affected the viscoelastic behavior of the emulsions; storage (G,) and loss modulus (G,) crossed-over at lower frequency values as compared to that of emulsions containing no polysaccharide. [source]

Modeling of the Phase Separation Behavior of Polydisperse Semi-Flexible Diblock Copolymers

MACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2004
Andreas John
Abstract Summary: A modified random phase approximation method with a cumulant expansion for the semi-flexible structure factor of diblock copolymers was exercised to describe the phase separation behavior of semi-flexible and polydisperse diblock copolymers. Scattering curves and spinodal diagrams were calculated applying monomer specific input parameters. The influence of polydispersity was included applying basic concepts of mathematical statistics utilizing several probability density distributions in the case of the two single blocks. In contrast to semi-flexibility, the main effect of polydispersity was found to shift the spinodal up, thus to enlarge the range of existence of the homogeneous phase. Twofold Schultz-Zimm distribution of diblock copolymers. [source]

Characterization of Phase Separation Behavior, Emulsion Stability, Rheology, and Microstructure of Egg White,Polysaccharide Mixtures

Flexible Organic Solar Cells: Nanoscale Phase Separation and High Photovoltaic Efficiency in Solution-Processed, Small-Molecule Bulk Heterojunction Solar Cells (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2009
Mater.
The inside cover of this issue illustrates the fabrication of lightweight and flexible organic solar cells, developed by B. Walker et al. on page 3063, from a solution of fullerene and diketopyrrolopyrrole-based materials. The texture of the organic film on the substrate was taken from an atomic force microscope phase image of the high performance device (4.4% power conversion efficiency), showing the phase separation behavior of the two molecular semiconducting materials. [source]

Direct characterization of phase behavior and compatibility in PET/HDPE polymer blends by confocal Raman mapping

JOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2007
Shuangyan Huan
Abstract Morphology, chemical distribution and domain size in poly(ethylene terephthalate)/high-density poly(ethylene) (PET/HDPE) polymer blends of various ratios prepared with and without maleic anhydride have been analyzed with confocal Raman mapping and SEM. The ratioimage method introduced here allows us to obtain enhanced chemical images with higher contrast and reliability. Compatibility numbers (Nc) are calculated to evaluate the compatibility of the blends. The incompatible polymer blends show heterogeneous distribution with phase separation behavior, while the semicompatible blends prepared with maleic anhydride show much smaller subphase distributions with less distinct interphases. After the blending modification by maleic anhydride of only 0.5%, the viscosity status and dispersibility between PET and HDPE could be substantially improved, and the interactions that exist between the two phases have also been proved by ATR-FT-IR results. High-spatial-resolution confocal Raman mapping coupled with the ratioimage method provides a very attractive way to characterize the compatibility and phase behavior of the polymer blend through different blending methodologies. Copyright © 2006 John Wiley & Sons, Ltd. [source]