Influence of the ultrasound cavitation intensity on reduced graphene oxide functionalization

Aleš Ručigaj (Author), Justin G. Connell (Author), Matevž Dular (Author), Boštjan Genorio (Author)

Abstract

Graphene is a valuable and useful nanomaterial due to its exceptionally high tensile strength, electrical conductivity and transparency, as well as the ability to tune its materials properties via functionalization. One of the most important features needed to integrate functionalized graphene into products via scalable processing is the effectiveness of graphene dispersion in aqueous and organic solvents. In this study, we aimed to achieve the functionalization of reduced graphene oxide (rGO) by sonication in a one-step process using polyvinyl alcohol (PVA) as a model molecule to be bound to the rGO surface. We investigated the influence of the sonication energy on the efficacy of rGO functionalization. The correlation between the performance of the high-intensity ultrasonic horn and the synthesis of the PVA functionalized rGO was thoroughly investigated by TGA coupled with MS, and IR, Raman, XPS, Laser diffraction, and SEM analysis. The results show that the most soluble PVA-functionalized rGO is achieved at 50% of the ultrasonic horn amplitude. Analysis of cavitation dynamics revealed that in the near vicinity of the horn it is most aggressive at the highest amplitude (60%). This causes rGO flakes to break into smaller domains, which negatively affects the functionalization process. On the other hand, the maximum of the pressure pulsations far away from the horn is reached at 40% amplitude, as the pressure oscillations are attenuated significantly in the 2-phase flow region at higher amplitudes. These observations corelate well with the measured degree of functionalization, where the optimum functionalized rGO dispersion is reached at 50% horn amplitude, and generally imply that cavitation intensity must be carefully adjusted to achieve optimal rGO functionalization.

Keywords

grafen oksid;polivinil alkohol;ultrasonikacija;funkcionalizacija površine;graphene oxide;poly(vinyl alcohol);ultrasonication;surface functionalization;

Data

Language:	English
Year of publishing:	2022
Typology:	1.01 - Original Scientific Article
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
UDC:	620.3:544.57
COBISS:	128495875
ISSN:	1350-4177
Views:	17
Downloads:	6
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	grafen oksid;polivinil alkohol;ultrasonikacija;funkcionalizacija površine;
Type (COBISS):	Article
Pages:	str. 1-10
Issue:	ǂVol. ǂ90
Chronology:	Nov. 2022
DOI:	10.1016/j.ultsonch.2022.106212
ID:	22400406