writer：Ran Niu, Jiang Gong, Donghua Xu*, Tao Tang, Zhao-Yan Sun*
keywords：Plate-like particles, Structure, Rheology, Negative normal stress differences, Interaction
source：期刊
specific source：Colloids and Surfaces A: Physicochemical and Engineering Aspects 470 (2015) 22-30
Issue time：2015年
The structures and rheological properties of three different plate-like particle suspensions, i.e., organically-modified montmorillonite (OMMT), graphene oxide (GO) and Kaolinite (Kaolin) in silicone oil (SO), are explored. Since the interactions between plate-like particle and SO are different, the dispersion states of these particles in SO are different. OMMT particles disperse relatively well in SO, and small clusters exist in GO/SO suspensions, but larger aggregates are found in Kaolin/SO suspensions. Moreover, liquid-crystalline ordering structure is found in both OMMT/SO and GO/SO suspensions, while it is absent in Kaolin/SO suspensions. Negative normal stress differences (ΔN) are observed during shear in all three plate-like particle suspensions, however, the mechanisms of the negative ΔN might be different. It can be further inferred that the negative ΔN in OMMT/SO suspensions results from the tumbling and rotating motions of OMMT sheets, while for GO/SO or Kaolin/SO suspensions, the negative ΔN results from the vorticity alignment of large GO clusters and Kaolin aggregates.