Dynamics of individual flexible polymers in a shear flow

Nature ◽  
10.1038/21148 ◽  
1999 ◽  
Vol 399 (6736) ◽  
pp. 564-566 ◽  
Author(s):  
Philip LeDuc ◽  
Charbel Haber ◽  
Gang Bao ◽  
Denis Wirtz
Keyword(s):  
Shear Flow ◽  
Flexible Polymers

Intrinsic viscosity of flexible polymers in unbounded and bounded Newtonian shear flow

1991 ◽  
Vol 24 (19) ◽  
pp. 5351-5356 ◽  
Author(s):  
J. H. Van Vliet ◽  
G. Ten Brinke
Keyword(s):  
Shear Flow ◽  
Intrinsic Viscosity ◽  
Flexible Polymers

Understanding conformational and dynamical evolution of semiflexible polymers in shear flow

Soft Matter ◽  
2019 ◽  
Vol 15 (31) ◽  
pp. 6353-6361 ◽  
Author(s):  
Xiangxin Kong ◽  
Yingchun Han ◽  
Wenduo Chen ◽  
Fengchao Cui ◽  
Yunqi Li
Keyword(s):  
Shear Strength ◽  
Shear Flow ◽  
Dynamical Evolution ◽  
Semiflexible Polymers ◽  
Flexible Polymers ◽  
Affine Deformation

At small and intermediate shear strength, flexible polymers show a quasi-affine deformation while semiflexible ones are initially unfolded from the center.

In Situ Dynamics of Concentrated DNA Molecules in a Shear Flow

1999 ◽  
Author(s):  
Philip LeDuc ◽  
Bryan Pfister ◽  
Yangqing Xu ◽  
Denis Wirtz ◽  
Gang Bao
Keyword(s):  
Shear Flow ◽  
Conformational Changes ◽  
Flow Direction ◽  
Polymer Concentration ◽  
Polymer Dynamics ◽  
Dna Molecules ◽  
Flexible Polymers ◽  
Shear Rates ◽  
Dna Solutions

Abstract Polymer dynamics has been studied for many years because of its importance in many areas including materials, mechanics, biology, and medicine (Munk, 1989; Hoffman, et al., 1984). The dynamics of macromolecules in shear flow has been studied using light scattering and birefringence, but the effect of shear on the dynamics of individual polymers is not well understood (Doi & Edwards, 1986; de Gennes, 1991; de Gennes, 1997). Recently we studied the conformational changes of DNA molecules under shear in dilute concentration (LeDuc et al., 1998). Here we report the observations of the dynamics of fluorescently-labeled DNA molecules in a shear flow with increased concentration. Under a controlled shear flow, these flexible polymers exhibit various extended conformations, which range from parallel to perpendicular in orientation when compared to the flow direction. The amount of stretching that occurs in these experiments is found to be less than that for the dilute concentrations of the DNA solutions. Further, the stretching of the molecular solutions is found even at shear rates much smaller than the inverse of the relaxation time of the molecule. The in situ observations also reveal the effect of polymer concentration on the entanglement of macromolecules. These results provide insight into the behavior of individual and concentrated polymer molecules under shear and help further development of models for polymer dynamics (Perkins, et al., 1994; Smith, et al., 1992; Wirtz, 1995).

scholarly journals Active Brownian Filamentous Polymers under Shear Flow

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 837 ◽  
Author(s):  
Aitor Martín-Gómez ◽  
Gerhard Gompper ◽  
Roland Winkler
Keyword(s):  
Shear Rate ◽  
Shear Flow ◽  
Persistence Length ◽  
Relaxation Times ◽  
Shear Thinning ◽  
Weissenberg Number ◽  
Flexible Polymers ◽  
Orientation Relaxation ◽  
Independent Behavior ◽  
Analytical Expressions

The conformational and rheological properties of active filaments/polymers exposed to shear flow are studied analytically. Using the continuous Gaussian semiflexible polymer model extended by the activity, we derive analytical expressions for the dependence of the deformation, orientation, relaxation times, and viscosity on the persistence length, shear rate, and activity. The model yields a Weissenberg-number dependent shear-induced deformation, alignment, and shear thinning behavior, similarly to the passive counterpart. Thereby, the model shows an intimate coupling between activity and shear flow. As a consequence, activity enhances the shear-induced polymer deformation for flexible polymers. For semiflexible polymers/filaments, a nonmonotonic deformation is obtained because of the activity-induced shrinkage at moderate and swelling at large activities. Independent of stiffness, activity-induced swelling facilitates and enhances alignment and shear thinning compared to a passive polymer. In the asymptotic limit of large activities, a polymer length- and stiffness-independent behavior is obtained, with universal shear-rate dependencies for the conformations, dynamics, and rheology.

Flexible polymers in a nematic medium: a Monte Carlo simulation

1993 ◽  
Vol 3 (5) ◽  
pp. 603-609 ◽  
Author(s):  
J. H. van Vliet ◽  
M. C. Luyten ◽  
G. ten Brinke
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Flexible Polymers
Sign in / Sign up

Export Citation Format

Share Document