• 文献标题:   Orientation effect on the rheology of graphene oxide dispersions in isotropic phase, ordered isotropic biphase, and discotic phase
  • 文献类型:   Article
  • 作  者:   CHOI GM, PARK M, JEONG SY, LEE HS
  • 作者关键词:   graphene oxide, rheology, orientation dynamic, phase behavior, liquid crystal, interlayer distance, leslieericksen model, dlvo theory
  • 出版物名称:   JOURNAL OF RHEOLOGY
  • ISSN:   0148-6055 EI 1520-8516
  • 通讯作者地址:  
  • 被引频次:   9
  • DOI:   10.1122/8.0000260
  • 出版年:   2021

▎ 摘  要

We present a combined simulation and experimental study of the structure and dynamics of dilute, semidilute, and concentrated graphene oxide aqueous alkaline dispersions. These materials behave as lyotropic systems, with phase ordering as the concentration increases. The sheet spacing in the ordered phases is much broader than that expected by the classical Derjaguin-Landau-Verwey-Overbeek theory. Rheological responses in the isotropic phase are similar to rod-like liquid crystals (LCs), which follow the simplified Leslie-Ericksen (LE) model. The dispersions in the biphase and the discotic phase behave similarly to polydomain LC polymers, following the mesoscopic LE model [Larson-Doi (LD) model]. The LD model fits the time evolution of shear stress at startup flow, re-startup flow after the cessation of flow, and reversal flow in the discotic phase. Further, the Folgar-Tucker-Lipscomb model fits the stress overshoot in a startup flow, but not the reversal flow.