A Landau-de Gennes theory for twist-bend and splay-bend nematic phases of colloidal suspensions of bent rods.

摘要: We develop a phenomenological Landau–de Gennes (LdG) theory for lyotropic colloidal suspensions of bent rods using Q-tensor expansion the chemical-potential dependent grand potential. In addition, we introduce bend flexoelectric term, coupling polarization and divergence Q-tensor, to study stability uniaxial (N), twist-bend (NTB), splay-bend (NSB) nematic phases rods. first show that mapping can be found between LdG Oseen–Frank theory. By breaking degeneracy splay elastic constants, find predicts either an N–NTB–NSB or N–NSB–NTB phase sequence upon increasing particle concentration. Finally, employ our first-order N–NTB transition, which K33 as well its renormalized version K33eff remain positive at whereas vanishes spinodal. connect these findings recent simulation results.