Rheological study of highly concentrated aqueous graphene oxide suspensions : the effects of concentration, particle lateral dimensions and number of layers per particle

Malnarič, Iris (author), Alič, Branko (author), Krajnc, Matjaž (author), Vesel, Alenka (author), Šebenik, Urška (author)

Aqueous graphene oxide (GO) suspensions have attracted considerable attention due to their unique properties, which can find numerous applications in various fields, from industry to biomedicine. When designing a GO hydrogel for a specific application, a thorough understanding of the effects of appropriate starting material properties and its concentration range on the suspension stability, structural and rheological properties is of essential importance. The present work is concerned with high solids content (from 1.00 to 2.00 w/v%) GO aqueous suspensions exhibiting marked elastic properties. The effects of the GO particles lateral dimensions and the number of GO layers per particle on the flow and viscoelastic properties are investigated. Rheological parameters useful for quantitative interpretation of the results were obtained by fitting the experimental data using Cross, Herschel-Bulkley, and generalized Maxwell models. All GO suspensions showed a marked shear thinning and thixotropic behaviour with a significant yield stress. Their mechanical spectra confirmed viscoelastic behaviour typical for a suspension in an arrested state. Observed differences in values of rheological parameters and their variations with concentration are explained by particle properties and corresponding rotational restrictions, electrostatic attraction/repulsion, nematic phase formation, and particle agglomeration. The research presents fundamental insights into the rheological properties of GO suspensions, which can be manipulated by varying particle geometry and concentration.

• Language: English
• Keywords: graphene oxide, aqueous suspension, rheology, particle size, oxidation degree
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 12 str.
• Numbering: Vol. 675, art. 132012
• PID: 20.500.12556/RUL-147665
• UDC: 62-911-026.743:532.135
• ISSN on article: 0927-7757
• DOI: 10.1016/j.colsurfa.2023.132012
• COBISS.SI-ID: 158337027
• Publication date in RUL: 10.07.2023

Record is a part of a journal

• Title: Colloids and surfaces. A, Physicochemical and engineering aspects
• Shortened title: Colloids surf., A Physicochem. eng. asp.
• Publisher: Elsevier
• ISSN: 0927-7757
• COBISS.SI-ID: 15328517

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: grafen oksid, vodna suspenzija, reologija, velikost delcev, stopnja oksidacije

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0191
• Name: Kemijsko inženirstvo

• Funder: ARRS - Slovenian Research Agency
• Project number: L2-1834
• Name: Ogljikove nanostene za supekondenzatorje prihodnosti