ELECTRORHEOLOGICAL FLUIDS CONTAINING GRAPHENE OXIDE SHEETS GRAFTED WITH POLY(METHYL METHACRYLATE)

1,2 CVEK Martin
Co-authors:
1 MRLIK Miroslav 3 ILCIKOVA Marketa 3 MOSNACEK Jaroslav 1 SEDLACIK Michal
Institutions:
1 Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Trida T. Bati 5678, 760 01 Zlin, Czech Republic, EU
2 Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, Vavreckova 275, 760 01 Zlin, Czech Republic, EU
3 Polymer Institute, Slovak Academy of Sciences, Dubravska cesta 9, 845 41 Bratislava 45, Slovakia, EU
Conference:
9th International Conference on Nanomaterials - Research & Application, Hotel Voronez I, Brno, Czech Republic, EU, October 18th - 20th 2017
Proceedings:
Proceedings 9th International Conference on Nanomaterials - Research & Application
Pages:
111-116
ISBN:
978-80-87294-81-9
ISSN:
2694-930X
Published:
8th March 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
49 views / 17 downloads
Abstract

Electrorheological (ER) fluids are fascinating materials with a wide range of potential applications. However, low performance in electric field and poor sedimentation stability are the most serious limitations for these applications. To reduce the mentioned drawbacks various materials such as graphene were explored. Recent efforts to improve performance of the ER fluids led to the modification of the graphene with polymer substances. Herein, the proposed ER structures are based on the graphene oxide (GO) sheets controllably grafted with poly(methyl methacrylate) (PMMA). The oxygen-containing functional groups introduced by modified Hummers method enabled the immobilization of 2-Bromoisobutyryl bromide onto the GO. The controlled PMMA chain growth was performed by atom transfer radical polymerization resulting in the GO-g-PMMA entities. The reaction process was monitored via nuclear magnetic resonance spectroscopy and gel permeation chromatography. The successful grafting process was confirmed via infrared spectroscopy. Conductivity of the neat GO as well as the fabricated GO-g-PMMA structures was investigated using four-point method, while their reduction was examined via Raman spectroscopy. Such particles were further thoroughly dispersed in silicone oil (SO) and the ER performance of as-prepared ER fluids was investigated. The system containing the GO-g-PMMA exhibited superior dynamic yield stress and higher ER effects as the modified particles were able to develop more rigid field-induced internal structures, due to the enhanced particle conductivity and thus better response to external electric field. The results also showed that the presence of PMMA grafts enhanced the compatibility with SO, which was reflected in substantially improved stability against sedimentation.

Keywords: electrorheology, steady shear, graphene oxide, surface modification, atom transfer radical polymerization
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