• 文献标题:   Tailored Colloidal Stability and Rheological Properties of Graphene Oxide Liquid Crystals with Polymer-Induced Depletion Attractions
  • 文献类型:   Article
  • 作  者:   SHIM YH, LEE KE, SHIN TJ, KIM SO, KIM SY
  • 作者关键词:   graphene oxide, polymer, molecular weight, liquid crystal, viscosity, rheology
  • 出版物名称:   ACS NANO
  • ISSN:   1936-0851 EI 1936-086X
  • 通讯作者地址:   Ulsan Natl Inst Sci Technol
  • 被引频次:   4
  • DOI:   10.1021/acsnano.8b06320
  • 出版年:   2018

▎ 摘  要

Graphene oxide liquid crystallinity (GO LC) has been widely exploited for high-performance graphene-based applications. In this regard, colloidal stability of GO LC suspension is a crucial requirement, particularly while polymers are often added to the GO LC. Unfortunately, current level of knowledge on how polymers influence the structure and properties of GO LC is not sufficient to systematically guide the development of applications. Here, we investigate the microstructure and rheological properties of GO LC suspensions in the presence of polymer additives with varying molecular weights and concentrations. Similar to conventional colloidal systems, non-negligible polymer-induced interactions are found in GO LC suspensions, which can effectively modulate the interaction among GO platelets and the relevant physical properties. On the basis of extensive small-angle X-ray scattering and rheological measurements, we demonstrate that, contrary to the general perception, polymer-induced depletion attraction can increase the colloidal stability of GO, while also preventing the vitrification of GO LC. In addition, a proper level of polymer additive can reduce the viscosity of GO LC suspensions by orders of magnitude, providing an effective route to GO LC-based solution processing. After all, the colloidal stability and rheological properties of GO can significantly impact the quality of GO. Therefore, we believe that our finding will be of great interest in the field of graphene-based applications, as it presents effective strategies for improving properties.