Pretransitional orientational ordering of rigid-rod polymers in shear flow

1993 ◽  
Vol 48 (6) ◽  
pp. 4455-4459 ◽  
Author(s):  
Chaohua Wang ◽  
B. E. Vugmeister ◽  
H. Daniel Ou-Yang
Keyword(s):  
Shear Flow ◽  
Rigid Rod ◽  
Orientational Ordering

Orientational Ordering of Rigid Rod Polymers in Shear Flow

1992 ◽  
Vol 289 ◽  
Author(s):  
B.E. Vugmeister ◽  
C. Wang ◽  
H.D. Ou-Yang
Keyword(s):  
Shear Flow ◽  
Order Parameter ◽  
Theoretical Study ◽  
Volume Fraction ◽  
Rotational Diffusion ◽  
Effective Interaction ◽  
Orientational Order ◽  
Flow Shear ◽  
Rigid Rod ◽  
Orientational Ordering

AbstractWe present the results of experimental and theoretical study of the orientational ordering of rigid rod like polymers in the presence of shear flow. Shear induced birefringence was measured to determine the dependence of orientational order parameter S=<3cos2θ−l>/2 on the shear rate at different values of the volume fraction. Experimental results are discussed in terms of an approximate solution of the rotational diffusion equation in the presence of shear flow based on the construction of the effective interaction energy.

scholarly journals Phase separation of rigid-rod suspensions in shear flow

1999 ◽  
Vol 60 (4) ◽  
pp. 4397-4415 ◽  
Author(s):  
Peter D. Olmsted ◽  
C.-Y. David Lu
Keyword(s):  
Phase Separation ◽  
Shear Flow ◽  
Rigid Rod

Attraction between like-charged surfaces induced by orientational ordering of divalent rigid rod-like counterions: theory and simulations

2009 ◽  
Vol 42 (10) ◽  
pp. 105401 ◽  
Author(s):  
Stefano Maset ◽  
Jurij Reščič ◽  
Sylvio May ◽  
Janez Ivan Pavlič ◽  
Klemen Bohinc
Keyword(s):  
Charged Surfaces ◽  
Rigid Rod ◽  
Orientational Ordering

scholarly journals Tumbling of a rigid rod in a shear flow

2014 ◽  
Vol 2014 (9) ◽  
pp. P09007 ◽  
Author(s):  
J M J van Leeuwen ◽  
H W J Blöte
Keyword(s):  
Shear Flow ◽  
Rigid Rod

Orientational Ordering of a Poly(oxyethylene)−Poly(oxybutylene) Diblock Copolymer Gel under Steady Shear Flow

1998 ◽  
Vol 31 (9) ◽  
pp. 2952-2956 ◽  
Author(s):  
John A. Pople ◽  
Ian W. Hamley ◽  
J. Patrick A. Fairclough ◽  
Anthony J. Ryan ◽  
Colin Booth
Keyword(s):  
Shear Flow ◽  
Diblock Copolymer ◽  
Steady Shear ◽  
Steady Shear Flow ◽  
Orientational Ordering

The rigid-rod model for nematic polymers: An analysis of the shear flow problem

1999 ◽  
Vol 43 (3) ◽  
pp. 829-843 ◽  
Author(s):  
V. Faraoni ◽  
M. Grosso ◽  
S. Crescitelli ◽  
P. L. Maffettone
Keyword(s):  
Shear Flow ◽  
Flow Problem ◽  
Rod Model ◽  
Rigid Rod ◽  
Nematic Polymers

Orientational ordering and disordering of a simple dipolar fluid under shear flow

2002 ◽  
Vol 117 (19) ◽  
pp. 9016-9027 ◽  
Author(s):  
J. Liam McWhirter ◽  
G. N. Patey
Keyword(s):  
Shear Flow ◽  
Dipolar Fluid ◽  
Orientational Ordering

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

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