Why only solubility parameters? Liquid-phase exfoliation from the point of view of colloidal chemistry

Author(s)

Damasceno, Joao Paulo Vita ; Caironi, Mario ; Kubota, Lauro Tatsuo

• Document type: Journal article
• Source: MATERIALS TODAY CHEMISTRY; v. 38, p. 8-pg., 2024-04-12.

Abstract

Liquid-phase exfoliation has been widely used to obtain 2D nanomaterials from layered or non-layered solids. Most reports have focused on exfoliation procedures using aqueous solutions of passivating agents, functionalized materials in water, or pristine materials in 'good' organic solvents. Herein, we highlight the third method applied to carbon nanomaterials because it results in stable and concentrated systems without any other additives, and the deposited materials form conductive patterns after solvent drying without the need for posttreatments like (electro)chemical reduction or removal of passivating agents. Good solvents for exfoliating pristine materials have been ascribed as having the 'correct' match of Hansen solubility parameters. Although this approach successfully enhances the yield in terms of mass concentration, it does not explain the high stability of dispersions prepared in liquids ascribed as 'bad' solvents or some properties observed for exfoliated materials in both 'good' and 'bad' ones, like sedimentation. In this review, we have reinterpreted organic dispersions of pristine carbon materials using concepts of Colloidal Chemistry, which can explain many poorly understood properties and guide new improvements in this area. (AU)

• FAPESP's process: 22/05053-4 - Preparation of carbon-based conductive inks for printed electronic devices
• Grantee: João Paulo Vita Damasceno
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis
• Grantee: Marco Aurelio Zezzi Arruda
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/22127-2 - Development of novel materials strategic for integrated analytical devices
• Grantee: Lauro Tatsuo Kubota
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/06604-9 - Conductive inks based on carbon nanomaterials for the preparation of electrodes applied to electrochemical devices
• Grantee: João Paulo Vita Damasceno
• Support Opportunities: Scholarships in Brazil - Post-Doctoral