Graphene-based composite with high stable dispersion in ethanol.

In the last few years a lot of applicative research studies are focused on graphene, a 2D carbo-material with very particular physical features like electro-conductivity, thermo-conductivity, mechanical stability, and its particular aspect ratio with a high surface and a negligible thickness (1–3). For that features the spectra of possibilities to make a new application with this material, are big and grow time after time. In addition, with climate change, the focus of research to make new technologies greener and with less impact, on the environment, than now has moved to increase the study of that material and most researchers have focused their studies on the possibility to disperse that material in a green solvent with low boiling point. One problem with pristine Graphene is that it could be dispersed with high concentration only in polar aprotic solvent as n-methyl-2-pyrrolidone or Dimethyl formamide (4), a solvent with a high boiling point and with high toxicity for the humans and the environment. Usually for that reason is preferred to use the oxidized form of graphene GO, most easy to disperse, and reduce in rGO. The reduced form has the problem of having more defects on the surface than pristine graphene losing a part of the natural performance of the graphene. Another method studied is the use of a surfactant (5)or making nano-composite material with the use of polar polymer such as the PVP (6–8) has permitted to disperse of the material with a good concentration in water. This research has moved used to investigate how to make new composite graphene-based, easy to disperse in an organic polar solvent such as ethanol. We made an uncontrolled growth of polymer (ethyl maleate derivate) on the surface of the material, for making that we use the support of the microwave reactor that, with the particular characteristic of the graphene to be a radical initiator, permits the formation of different particles of polymer maleate based on the surface of the graphene. This material has good stability in ethanol and maintains that feature after a long time. That dispersion opens the possibility to make ink graphene-based or coating on other surfaces and other different applications with the fast removal of the solvent. At the same time the uncontrolled growing permit the removal of the composite with the heating of the material in an inert atmosphere to obtain pristine graphene with a low number of defects. Bibliography 1. Clancy AJ, Bayazit MK, Hodge SA, Skipper NT, Howard CA, Shaffer MSP. Charged Carbon Nanomaterials: Redox Chemistries of Fullerenes, Carbon Nanotubes, and Graphenes. Chem Rev. 2018;118(16):7363-7408. doi:10.1021/acs.chemrev.8b00128 2. Randviir EP, Brownson DAC, Banks CE. A decade of graphene research: Production, applications, and outlook. Mater Today. 2014;17(9):426-432. doi:10.1016/j.mattod.2014.06.001 3. Wei W, Qu X. Extraordinary physical properties of functionalized graphene. Small. 2012;8(14):2138-2151. doi:10.1002/smll.201200104 4. Vacacela Gomez C, Guevara M, Tene T, et al. The liquid exfoliation of graphene in polar solvents. Appl Surf Sci. 2021;546(December 2020):149046. doi:10.1016/j.apsusc.2021.149046 5. Wang S, Yi M, Shen Z, Zhang X, Ma S. Adding ethanol can effectively enhance the graphene concentration in water-surfactant solutions. RSC Adv. 2014;4(48):25374-25378. doi:10.1039/c4ra03345k 6. Laaksonen P, Kainlauri M, Laaksonen T, et al. Interfacial engineering by proteins: Exfoliation and functionalization of graphene by hydrophobins. Angew Chemie - Int Ed. 2010;49(29):4946-4949. doi:10.1002/anie.201001806 7. Perumal S, Lee HM, Cheong IW. High-concentration graphene dispersion stabilized by block copolymers in ethanol. J Colloid Interface Sci. 2017;497:359-367. doi:10.1016/j.jcis.2017.03.027 8. Wajid AS, Das S, Irin F, et al. Polymer-stabilized graphene dispersions at high concentrations in organic solvents for composite production. Carbon N Y. 2012;50(2):526-534. doi:10.1016/j.carbon.2011.09.008