Rheological Properties of Silica Suspensions and Visualization of the Network Structures

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09650985
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 高分子構造・物性(含繊維)
• Research Institution: Chiba University
• Principal Investigator: KOSEKI Kenichi Chiba University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (70092054)
• Co-Investigator(Kenkyū-buntansha): ISHII Chiaki Chiba University, Faculty of Engineering, Research Associate, 工学部, 助手 (30291305) ; AMARI Takeshi Chiba University, Faculty of Engineering, Professor, 工学部, 教授 (90013185)
• Project Period (FY): 1997 – 1998
• Keywords: Network Structure / Silica Suspension / Viscoelastic Properties / Rheology / Photopolymerization / TEM

Research Abstract

Fumed silica was dispersed in acrylate monomer by a roll mill. The silica aerosil (A200 ; Degussa Co.) was used for dispersed particle. The diameter and the density of powder were 12nm and 2.2g/cm^3, respectively. Photosensitive disperse medium was two functional acrylate monomer sensitized with photosensitive radical generator. Dynamic viscoelastic properties were measured by computer aided rheometer with a cone and plate geometry. All measurements were carried out at 25ﾟC.All suspension show typical shear thinning. We can deduce that the flocculated network structure depending on the concentration is broken down by steady shearing. The dependence of on the angular frequency without steady shear flow shows the characteristics of a concentrated suspension, namely the G' is independent of this frequency. After applying steady shear, the viscous film samples were polymerized by UV irradiation for fixing the structure. The results showed that the formation or deformation of the network structure by shearing estimated from the rheologycal behaviors of silica suspension was consistent with the TEM observation.