scholarly journals A Local-Exchange Model of Folding Chain Surface of Polymer Crystal Based on Worm-Like Chain Model within Single-Chain in Mean-Field Theory

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2555
Author(s):  
Hongyi Xiao ◽  
Xinghua Zhang ◽  
Dadong Yan
Keyword(s):  
Surface Tension ◽  
Mean Field Theory ◽  
Mean Field ◽  
Amorphous Layer ◽  
Chain Model ◽  
Single Chain ◽  
Lamellar Crystal ◽  
Local Exchange ◽  
Entry Model ◽  
Optimal Distance

The structure of amorphous layer of folding surface controls the properties of the polymer lamellar crystal, which consists of chains with a loop conformation. The surface tension depends on the length and the distance between two injection points of the loop which involving the reptation motion and lateral exchange motion of the stems. In the present work, a local-exchange motion model based on the worm-like chain model is developed to investigate the effects of lateral motion of stems on the release the surface tension. The optimal distance between two injection points is determined by the balance of chain bending energy and conformational entropy. The numerical results provide evidences to the adjacent re-entry model for various loop lengths. A possible explanation involving density of injection points is proposed to interpret the mechanism.

scholarly journals Single Chain Mean-Field Theory Study on Responsive Behavior of Semiflexible Polymer Brush

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 778
Author(s):  
Yingli Niu ◽  
Xiangyu Bu ◽  
Xinghua Zhang
Keyword(s):  
Field Theory ◽  
Message Passing Interface ◽  
Mean Field Theory ◽  
Mean Field ◽  
Algorithmic Complexity ◽  
Ensemble Average ◽  
Single Chain ◽  
Metropolis Monte Carlo ◽  
Rigid Rod ◽  
Chain Conformations

The application of single chain mean-field theory (SCMFT) on semiflexible chain brushes is reviewed. The worm-like chain (WLC) model is the best mode of semiflexible chain that can continuously recover to the rigid rod model and Gaussian chain (GC) model in rigid and flexible limits, respectively. Compared with the commonly used GC model, SCMFT is more applicable to the WLC model because the algorithmic complexity of the WLC model is much higher than that of the GC model in self-consistent field theory (SCFT). On the contrary, the algorithmic complexity of both models in SCMFT are comparable. In SCMFT, the ensemble average of quantities is obtained by sampling the conformations of a single chain or multi-chains in the external auxiliary field instead of solving the modified diffuse equation (MDE) in SCFT. The precision of this calculation is controlled by the number of bonds Nm used to discretize the chain contour length L and the number of conformations M used in the ensemble average. The latter factor can be well controlled by metropolis Monte Carlo simulation. This approach can be easily generalized to solve problems with complex boundary conditions or in high-dimensional systems, which were once nightmares when solving MDEs in SCFT. Moreover, the calculations in SCMFT mainly relate to the assemble averages of chain conformations, for which a portion of conformations can be performed parallel on different computing cores using a message-passing interface (MPI).

Development of an Importance Sampling Single Chain Mean Field Theory for Polymer Adsorption onto a Flat Wall

2004 ◽  
Vol 37 (3) ◽  
pp. 1124-1133 ◽  
Author(s):  
Josep Bonet Avalos ◽  
Allan D. Mackie ◽  
Silvia Díez-Orrite
Keyword(s):  
Field Theory ◽  
Importance Sampling ◽  
Mean Field Theory ◽  
Mean Field ◽  
Polymer Adsorption ◽  
Single Chain ◽  
Flat Wall

Surface tension of a Yukawa fluid according to mean-field theory

2017 ◽  
Vol 146 (13) ◽  
pp. 134701 ◽  
Author(s):  
Guilherme Volpe Bossa ◽  
Joseph Norris ◽  
Sylvio May
Keyword(s):  
Field Theory ◽  
Surface Tension ◽  
Mean Field Theory ◽  
Mean Field ◽  
Yukawa Fluid

scholarly journals Thermodynamics of droplets undergoing liquid-liquid phase separation

2021 ◽  
Author(s):  
Subhadip Biswas ◽  
Biswaroop Mukherjee ◽  
Buddhapriya Chakrabarti
Keyword(s):  
Surface Tension ◽  
Phase Separation ◽  
Liquid Phase ◽  
Volume Fraction ◽  
Mean Field Theory ◽  
Equilibrium Phase ◽  
Mean Field ◽  
Liquid Phase Separation ◽  
Polymer Mixture ◽  
Liquid Liquid Phase Separation

We study the thermodynamics of binary mixtures wherein the volume fraction of the minority component is less than the amount required to form a flat interface. Based on an explicit microscopic mean field theory, we show that the surface tension dominated equilibrium phase of a polymer mixture forms a single macroscopic droplet. A combination of elastic interactions that renormalize the surface tension, and arrests phase separation for a gel-polymer mixture, stabilize a micro-droplet phase. We compute the droplet size as a function of the interfacial tension, Flory parameter, and elastic moduli of the gel. Our results illustrate the importance of the rheological properties of the solvent in dictating the thermodynamic phase behavior of biopolymers undergoing liquid-liquid phase separation.

scholarly journals Topological changes in telechelic micelles: flowers versus stars

2021 ◽  
Author(s):  
Vladimir Baulin
Keyword(s):  
Smart Materials ◽  
Linear Chain ◽  
Mean Field Theory ◽  
Mean Field ◽  
Polymer Chains ◽  
Linear Polymers ◽  
Stimuli Responsive ◽  
Single Chain ◽  
Low Concentrations ◽  
Effective Attraction

Micellization and morphology of spherical telechelic micelles formed by tri-block copolymers with short solvophobic end blocks at low concentrations is discussed within scaling arguments and Single Chain Mean Field Theory (SCMFT). In ultra-dilute regime, individual telechelic polymer chains can exist in solution in two distinct states: open linear chain conformation with two free ends and closed loop conformation, when two ends are connected by the effective attraction between two solvophobic ends. At concentrations below gelation point, closed loops tend to form micelles comprised mostly of loops in flower-like micelles, while linear polymers in open conformations tend to form star-shaped aggregates with one hydrophobic dangling end. Resulting two kinds of micelles have remarkably different topology and dimensions, while the transition between them can be driven by the entropy, namely conformation changes between domination of the looped and linear conformations. As a result, the transition between two types of micelles lies in a narrow interaction parameters range. Thus, these topological micelles are very sensitive to the changes in external environment and they can serve as a very sensitive stimuli-responsive smart materials.

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