Tailoring Graphene Nanosheets for Highly Improved Dispersion Stability and Quantitative Assessment in Nonaqueous Solvent

Abstract

Aggregation is a critical limitation for the practical application of graphene-based materials. Herein, we report that graphene oxide (GO) nanosheets chemically modified with ethanolamine (EA), ethylene glycol (EG), and sulfanilic acid (SA) demonstrate superior dispersion stability in organic solvents, specifically EG, based on the differences in their covalent chemistries. Functionalized GO was successfully dispersed in EG at a concentration of 9.0 mg mL(-1) (0.50 vol %), the highest dispersion concentration reported to date. Moreover, our study introduces a unique analytical method for the assessment of dispersion stability and successfully quantifies the instability index based on transmission profiles under centrifugation cycles. Interestingly, GO-EG and GO-EA exhibited highly improved dispersion stabilities approximately 96 and 48 times greater than that of GO in EG solvent, respectively. This finding highlights the critical role of surface functional groups in the enhancement of chemical affinity and miscibility in the surrounding media. We anticipate that the novel structural designs and unique tools presented in this study will further the understanding and application of chemically functionalized carbon materials.

Efficient Drug Delivery Carrier Surface without Unwanted Adsorption Using Sulfobetaine Zwitterion

“…Moreover, the high colloidal stability of SiZwit has been verified by designing a method using UV–vis spectroscopy and centrifugation. [ 27 ] The synthetic method for SiZwit is divided into two steps. First, we functionalized silica nanoparticles with an amino group using (3‐aminopropyl)triethoxysilane (APTES, SiNH 2 ), which is a well‐known amine functionalizing agent.…”

“…Moreover, the high colloidal stability of SiZwit has been verified by designing a method using UV-vis spectroscopy and centrifugation. [27] The Many studies describing the high colloidal stability and antifouling effects of zwitterion nanoparticles are reported; however, to date, disadvantages including complex synthetic methods and lack of methods for hydration layer analysis persist. In this study, zwitterion nanoparticles (SiZwit) are synthesized using (3-aminopropyl)triethoxysilane and 1,3-propane sultone and the hydration layer and colloidal stability of SiZwit are analyzed.…”

Recent trends in covalent functionalization of 2D materials

“…326,327 Carbodiimide is also used as a coupling agent for conversion reactions, from carboxyl to thioester (-COSR) 328,329 and the amide (-CONR) group. [330][331][332][333][334][335][336][337] Carboxyl reacts with thiol/thiourea to produce a thioester structure.…”

Ethylene glycol nanofluids dispersed with monolayer graphene oxide nanosheet for high-performance subzero cold thermal energy storage

“…34,35 Usually, time-consuming surface modication with various surfactants is required to keep their dispersion stability. 36,37 The surface ligands or polymer chains, however, would interfere with the liquid-solid phase change, delay the solidication process 38,39 and impede heat transfer. 40 Therefore, developing self-dispersible GO-EG nanouids with combined low supercooling, high thermal conductivity, large latent heat and good dispersion stability is critical for highperformance solid-liquid phase change-based subzero CTES.…”