scholarly journals Anomalous Phase Separation Kinetics Observed in a Micelle System

1994 ◽  
Vol 366 ◽  
Author(s):  
J. P. Wilcoxon ◽  
J. E. Martin
Keyword(s):  
Phase Separation ◽  
Domain Size ◽  
Anomalous Behavior ◽  
Domain Growth ◽  
Cube Root ◽  
Phase Separation Kinetics ◽  
Scattering Study ◽  
Evolution Of Structure ◽  
Spherical Micelles ◽  
Micelle System

ABSTRACTWe report a real-time, two-dimensional light scattering study of the evolution of structure of a two component nonionic micelle system undergoing phase separation. The micelles act like molecular slug-a-beds whose domain growth is pathetically lathargic (i.e. slower than the cube root of time prediction for simple binary fluids). In fact, the growth kinetics can be empirically described as a stretched exponential approach to a pinned domain size. Although the kinetics are not yet understood, this anomalous behavior may be due to the ability of the spherical micelles to reorganize into more complex structures.

Modification of Interfacial Properties of Polymer Blends with Diblock Copolymer

1996 ◽  
Vol 461 ◽  
Author(s):  
S. Kim ◽  
C. C. Han
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Polymer Blends ◽  
Diblock Copolymer ◽  
Diblock Copolymers ◽  
Phase Region ◽  
Domain Growth ◽  
Two Phase ◽  
Phase Separation Kinetics ◽  
Styrene Butadiene

ABSTRACTThe effect of diblock copolymer on the phase-separation process of polymer blends has been investigated by using light scattering and optical microscopic observations. To quench the system into the two phase region, a shear-jump technique is employed instead of the conventional temperature-jump technique. The samples studied are blends of low-molecular-weight polystyrene and polybutadiene with and without added styrene-butadiene block copolymer as a compatibilizer. It was observed that the addition of diblock copolymers could accelerate the phase separation kinetics depending on the shear history. As the concentration of diblock copolymer increases, the distribution of domain sizes becomes narrower and the growth rate slows down. The extent of slowing-down depends on the molecular weight and concentration of the copolymer. The time dependence of domain growth is clearly observed with optical microscopy.

THE EFFECT OF VISCOSITY ON THE PHASE SEPARATION DYNAMICS OF BINARY IMMISCIBLE MIXTURE COUPLED WITH REVERSIBLE REACTION

2010 ◽  
Vol 21 (12) ◽  
pp. 1479-1488 ◽  
Author(s):  
HUI LI ◽  
HONG LIU ◽  
ZHONG-YUAN LU ◽  
QIN WANG ◽  
CHIA-CHUNG SUN
Keyword(s):  
Phase Separation ◽  
Reaction Rate ◽  
Domain Size ◽  
Reaction Rates ◽  
Two Dimensions ◽  
Domain Growth ◽  
Reversible Reaction ◽  
Growth Exponent ◽  
High Reaction ◽  
Immiscible Mixture

The phase-separating system coupled with a simple reversible reaction A ⇌ B in a binary immiscible mixture due to critical quench is investigated with Lowe-Andersen temperature controlling method in two dimensions. The system viscosity strongly influences the asymptotic relationship between the excess energy (characterizing the domain growth) and the reaction rate. The competition between different dynamic factors results in the steady states with characteristic domain sizes. For low viscosities, the domain growth exponent approximates to 0.4 in the cases of low reaction rates and to 0.25 in the cases of high reaction rates, which shows the suppressing effects of high reversible reaction rates on the phase separation. However, in the cases of high viscosities, we find a 0.25 scaling with low reaction rates but a 0.5 scaling with high reaction rates. In these cases, high viscosities prevent mass transport in the binary mixture, consequently result in much smaller steady state domain sizes. Therefore the domain sizes with high viscosities and low reaction rates are very similar to those with low viscosities and high reaction rates, and the dependence of domain sizes on the reaction rates are similar. For the high-viscosity systems with high reaction rates, the domain sizes are predominantly controlled by the reaction rates, therefore we can observe stronger dependence of domain size on the reaction rate.

scholarly journals Methodologies and formalisms of resonance energy transfer in biophysics. Application to membrane model systems

2003 ◽  
Vol 5 (4) ◽  
pp. 223-231 ◽  
Author(s):  
Luís M. S. Loura ◽  
Rodrigo F. M. de Almeida ◽  
Manuel Prieto
Keyword(s):  
Energy Transfer ◽  
Phase Separation ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Domain Size ◽  
Model Systems ◽  
Distribution Models ◽  
Time Resolved ◽  
Phase Separation Kinetics ◽  
Mean Concentration

The formalisms of resonance energy transfer (RET) to a distribution of acceptors are reviewed for several geometries relevant to membranes (planar, bilayer, multilayer) and random probe distribution. Models for nonrandom probe distribution (mean concentration model, phase separation model) are presented. Selected examples of quantitative applications of RET to these systems are described. It is illustrated how information about domain size, partition coefficients, phase composition, phase separation kinetics and bilayer aggregation can be obtained from time-resolved RET data.

Numerical investigation of the growth kinetics for macromolecular microsphere composite hydrogel based on the TDGL equation

2016 ◽  
Vol 15 (08) ◽  
pp. 1650064
Author(s):  
Dating Wu ◽  
Hui Zhang
Keyword(s):  
Phase Separation ◽  
Numerical Investigation ◽  
Growth Kinetics ◽  
Pair Correlation ◽  
Domain Size ◽  
Time Dependent ◽  
Domain Growth ◽  
Ginzburg Landau ◽  
Tdgl Equation ◽  
Kinetics Of

We present results of a detailed numerical investigation of the phase separation kinetic process of the macromolecular microsphere composite (MMC) hydrogel. Based on the Flory-Huggins-de Gennes-like reticular free energy, we use the time-dependent Ginzburg–Landau (TDGL) mesoscopic model (called MMC-TDGL model) to simulate the phase separation process. Domain growth is investigated through the pair correlation function. Then we obtain the time-dependent characteristic domain size, which reflects the growth kinetics of the MMC hydrogel. The results indicate that the growth law based on the MMC-TDGL equation is consistent with the modified Lifshitz–Slyozov theory.

A Time-Resolved Low-Angle Light Scattering Apparatus. Application to Phase Separation Problems in Polymer Systems

2001 ◽  
Vol 66 (6) ◽  
pp. 973-982 ◽  
Author(s):  
Čestmír Koňák ◽  
Jaroslav Holoubek ◽  
Petr Štěpánek
Keyword(s):  
Phase Separation ◽  
Light Scattering ◽  
Signal To Noise Ratio ◽  
Scattered Light ◽  
Ccd Camera ◽  
Time Resolved ◽  
Polymer Systems ◽  
Software Analysis ◽  
Phase Separation Kinetics ◽  
Small Angle Light Scattering

A time-resolved small-angle light scattering apparatus equipped with azimuthal integration by means of a conical lens or software analysis of scattering patterns detected with a CCD camera was developed. Averaging allows a significant reduction of the signal-to-noise ratio of scattered light and makes this technique suitable for investigation of phase separation kinetics. Examples of applications to time evolution of phase separation in concentrated statistical copolymer solutions and dissolution of phase-separated domains in polymer blends are given.

scholarly journals Tunable thermo-reversible bicontinuous nanoparticle gel driven by the binary solvent segregation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuyin Xi ◽  
Ronald S. Lankone ◽  
Li-Piin Sung ◽  
Yun Liu
Keyword(s):  
Phase Separation ◽  
Domain Size ◽  
Binary Solvent ◽  
Colloidal Systems ◽  
Colloidal Assembly ◽  
Structures And Properties ◽  
Wide Range ◽  
Equilibrium Process ◽  
Equilibrium Structures ◽  
Non Equilibrium

AbstractBicontinuous porous structures through colloidal assembly realized by non-equilibrium process is crucial to various applications, including water treatment, catalysis and energy storage. However, as non-equilibrium structures are process-dependent, it is very challenging to simultaneously achieve reversibility, reproducibility, scalability, and tunability over material structures and properties. Here, a novel solvent segregation driven gel (SeedGel) is proposed and demonstrated to arrest bicontinuous structures with excellent thermal structural reversibility and reproducibility, tunable domain size, adjustable gel transition temperature, and amazing optical properties. It is achieved by trapping nanoparticles into one of the solvent domains upon the phase separation of the binary solvent. Due to the universality of the solvent driven particle phase separation, SeedGel is thus potentially a generic method for a wide range of colloidal systems.

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