Journal ArticleDOI
Dynamic coupling between stress and composition in polymer solutions and blends
Masao Doi,Akira Onuki +1 more
TLDR
In this article, a general expression for the time-correlation function of the polymer concentration around equilibrium and examine its relaxation in some typical cases is given, which can be used for gelling solutions and explains previous dynamic light scattering experiments at the sol-gel transition.Abstract:
Phenomenological hydrodynamic equations are proposed for entangled polymer blends as generalization of those for polymer solutions. They can describe coupling between macroscopic flow and relative diffusion. The key concept we use is the "tube velocity" introduced by Brochard in the problem of mutual diffusion in polymer blends. As applications, (I) we give a general expression for the time-correlation function of the polymer concentration around equilibrium and examine its relaxation in some typical cases. It can be strongly influenced by the viscoelastic effect when the two polymers have different lengths. Our expression can also be used for gelling solutions and explains previous dynamic light scattering experiments at the sol-gel transition. (ii) Detailed calculations are performed for the case of a single rheological relaxation time (the Maxwell model). The steady state structure factor is obtained to Iinear order in macroscopic flow. (iii) We predict that composition inhomogeneity is created in mixtures oflong and short polymers undergoing nonuniform flow. Its origin is that the longer chains support stress more than the shorter ones and the resultant imbalance of stress causes relative motion of the two polymers. These results are applicable both to solutions and blends.read more
Citations
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The self-assembly, aggregation and phase transitions of food protein systems in one, two and three dimensions
Raffaele Mezzenga,Peter Fischer +1 more
TL;DR: This review will tackle the current understanding of protein aggregation in the framework of foods, which is possibly one of the broadest contexts, yet is of tremendous daily relevance.
Journal ArticleDOI
Viscoelastic phase separation
TL;DR: In this paper, the authors review the experiments, theories and numerical simulations for viscoelastic phase separation, focusing on the differences from those of usual phase separation and highlight the significance of visco-elastic phases in pattern formation in Nature and its engineering applications.
Journal ArticleDOI
Phase transitions of fluids in shear flow
TL;DR: In this article, the effects of shear in fluids undergoing phase transitions are reviewed, focusing on near-critical fluids and polymer solutions as representative examples, but also discuss related problems in polymer blends, gels, and surfactant systems.
Journal ArticleDOI
Osmotic spreading of Bacillus subtilis biofilms driven by an extracellular matrix
Agnese Seminara,Thomas E. Angelini,James N. Wilking,Hera Vlamakis,Senan Ebrahim,Roberto Kolter,David A. Weitz,Michael Brenner +7 more
TL;DR: It is proposed that the secretion of EPS drives surface motility by generating osmotic pressure gradients in the extracellular space, and a simple mathematical model based on the physics of polymer solutions shows quantitative agreement with experimental measurements of biofilm growth, thickening, and spreading.
Journal ArticleDOI
Advances in Mechanics of Soft Materials: A Review of Large Deformation Behavior of Hydrogels
TL;DR: In this paper, the authors provide a bird's eye view of the mechanics of hydrogels, in particular the theories associated with deformation and the phenomena that are commonly observed.
References
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Book
The theory of polymer dynamics
Masao Doi,Sam F. Edwards +1 more
TL;DR: In this article, the viscoelasticity of polymeric liquids was studied in the context of rigid rod-like polymers and concentrated solutions of rigid rods like polymers.