Guidelines for Tailored Chemical Functionalization of Graphene

Abstract

Graphene oxide (GO) has been synthesized by the Hummers method with modification of experimental condition by different research groups, but there is no guideline to prepare tailored GO for targeted applications. In this research, we suggest a guideline for tailor-fittable functionalization of graphene on the basis of the scope of our previous report on the two-step oxidation of GO. We describe a detailed procedure for synthesis of GO, effects of degree of step I oxidation on characteristics of GO and comparing them with effects of degree of step II oxidation. Characteristic changes of GO occurring during step I oxidation and those occurring during step II oxidation are different in species of oxygen functional groups, interlayer spacing, thermal stability, size distribution, and yield of GO. On the basis of the results, three types of tailor-fitted GO for a fiber, transparent conducting film, and hydrogen storage material are synthesized by controlling the degree of step I and step II oxidation. Compared to the reference GO synthesized by conventional modified Hummers method, the tailor-fitted GO showed 33.5%, 117%, and 104% enhanced performance in strength of the fiber, figure of merits of transparent conducting film, and hydrogen storage, respectively. Our results show that the performance of GO based application is significantly influenced by the synthesis condition of GO, and optimized performance of the applications can be obtained by the tailor-fitted functionalization of GO. We anticipate that this study would be helpful for a variety of researches, both synthesis and application of GO.

Correlation between Molecular Structure and Interfacial Properties of Edge or Basal Plane Modified Graphene Oxide

“…Chong Rae Park et al has provided us guidelines to prepare tailored GO for targeted applications. 7 In 2003, Deḱańy et al reported modified GOs by grafting primary aliphatic amines and amino acids onto its surface. 8 Since then, many researchers have tried different methods to realize the modification of GO, and the fGOs show great potential applications.…”

Efficient room-temperature production of high-quality graphene by introducing removable oxygen functional groups to the precursor

“…The addition of water (previously identified as the second oxidation step in CGO synthesis)27,28 served as the important factor in the formation of structural defects. In the preparation of GO-20 and GO-5, this step was skipped by terminating the reaction in excess water at room temperature (Experimental section).…”

“…The final product, with a bright yellow appearance, was found to be highly dispersible in water, with a defect-rich nanostructure 26. However, over-oxidation in the second step of functionalization27,28 results in the formation of unrepairable structural defects that severely deteriorate the material performance of the reduced GO (rGO). Modifications to the traditional recipe have been reported continuously 29–32.…”

Facile Fabrication of Polyvinyl Alcohol/Edge-Selectively Oxidized Graphene Composite Fibers

“…All chemicals were used without further purification. EOG and GO were synthesized based on our previously reported methods [3,4,21] and prepared as colloidal suspensions with various concentrations (up to 12 mg/mL). The size of the EOG and GO was 2.5 um and 25 μm, respectively.…”

“…The ultrahigh tensile strength (~130 GPa) and Young’s modulus (~1 TPa) of graphene [1] make it an excellent nanofiller to enhance the mechanical properties of composites [2]; however, its poor dispersibility prevents the preparation of high-strength composites. Thus, graphene oxide (GO) can be used as an alternative because of the high dispersibility induced by its oxygen functional groups, including hydroxyl, epoxide, and carboxyl groups [2,3,4,5]. Indeed, GO has improved the mechanical properties of epoxy [6], poly(L-lactic acid) [7], polycarbonate [8], and polyimide [9,10].…”