Transient rheological responses in sheared biaxial liquid crystals

• Published in: Rheologica acta Vol. 49; no. 7; pp. 699 - 717
• Main Authors: Sircar, Sarthok, Wang, Qi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.07.2010; Springer; Springer Nature B.V
• Subjects: Amplitudes; Applied sciences; Aspect ratio; Axial stress; Characterization and Evaluation of Materials; Chemistry and Materials Science; Complex Fluids and Microfluidics; Exact sciences and technology; Food Science; Liquid crystal polymers; Liquid crystals; Materials Science; Mechanical Engineering; Organic polymers; Original Contribution; Physicochemistry of polymers; Polymer Sciences; Polymers; Properties and characterization; Rheological properties; Rheology; Rheology and viscoelasticity; Shear stress; Soft and Granular Matter; Time dependence; Bent-core liquid crystals; Linear viscoelasticity; Shear flows; Biaxial liquid crystals; Kinetic theory; Polymers; Smoluchowski equation; Viscoelasticity; Shear flow; Theoretical study; Modeling; Oscillating flow; Liquid crystal polymers; Numerical simulation; Rheological properties
• ISSN: 0035-4511; 1435-1528
• DOI: 10.1007/s00397-010-0440-2

We study the rheological response of monodomain ellipsoidal biaxial liquid crystal polymers (BLCP) as well as bent-core or V-shaped liquid crystal polymers (VLCP) subject to steady and time-dependent small amplitude oscillatory shear in selected regions of the model as well as flow parameter space. We adopt the two newly developed hydrodynamical kinetic theories for ellipsoidal BLCPs and VLCPs, respectively (Sircar and Wang, PRE 78:061702, 2008 , J Rheol 53:819–858, 2009 ; Sircar et al., Comm Math Sci (in press), 2010 ), in which a generalized Straley’s potential is used to represent the pairwise mean-field interaction of the mesoscopic system in biaxial phases. Transient shear stresses and normal stress differences corresponding to steady and small amplitude oscillatory shear are investigated; their variations with respect to the strength of the intermolecular potential, types of biaxial interaction, and changes in the aspect ratios for ellipsoidal BLCPs and the bent angle for VLCPs are explored.