Effect of doping graphene oxide on the structure and properties of SiO₂ based high emissivity coatings

Abstract

High emissivity coatings have received a great attention due to their energy saving capability for using in spacecraft and industrial furnaces applications. In this study, a feasible spray deposition method was employed to prepare a high emissivity coating on Kovar alloy substrate with porous structure after heat treatment. Graphene oxide was used to dope coating to improve its emissivity. The emissivity enhancement mechanisms of the graphene oxide doped SiO2 coatings have been investigated. Results show that coating emissivity can be significantly improved (6.41 and 9.64% of coating emissivity at 500 and 800°C, respectively) by doping graphene oxide. Thus, this study proposed a feasible and effective method to prepare high emissivity coatings. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48794.

Dual-Emitter Graphene Glass Fiber Fabric for Radiant Heating

“…Notably, glass fiber is a good infrared radiation material originating from the Si−O bond vibration with high emissivity around 0.8. 1,19 Based on the theoretical emissivity of 0.023 for monolayer graphene, GGFF-300 with ∼15 layers of graphene would present an emissivity of 0.29 (see details in Supplementary Note). 22 Actually, the emissivity of GGFF-300 is 0.84, much higher than the theoretical value of 0.29 (Figure 2c).…”

“…Graphene is an electrothermal material benefiting from its great electrical and thermal conductivity, 12−17 and infrared radiation can be emitted through lattice vibration. 4,18,19 Graphene exhibits wavelength-independent but layer-dependent emissivity (absorptivity) from visible to infrared spectrum range. 4,18,20−22 Therefore, the compatibility of the electrothermal properties and infrared radiation characteristics allows graphene to be a promising infrared electrothermal material.…”

“…component being silica, is a good infrared radiation material originating from the Si−O bond vibration, showing high infrared emissivity around 0.8. 1,19 Considering the properties of graphene and glass fibers, the design of combining these two materials to develop an advanced dual-emitter infrared electrothermal material, graphene glass fiber (GGF), was proposed, where graphene works as the heating element and both components work as the radiating elements. Herein, chemical vapor deposition (CVD) was used to realize the preparation of GGF, including GGF bundles (GGFB) and fabric (GGFF), by directly growing graphene on glass fibers.…”

“…Graphene is an electrothermal material benefiting from its great electrical and thermal conductivity, − and infrared radiation can be emitted through lattice vibration. ,, Graphene exhibits wavelength-independent but layer-dependent emissivity (absorptivity) from visible to infrared spectrum range. ,,− Therefore, the compatibility of the electrothermal properties and infrared radiation characteristics allows graphene to be a promising infrared electrothermal material. However, the emissivity of monolayer graphene is 0.023, so multilayer graphene is always needed to realize the high emissivity, and micro- and macrostructure design has also been employed to enhance the infrared radiation. , In addition, the combination of graphene with other high-emissivity materials is also expected to be an effective way to develop advanced, high-performance infrared radiation materials.…”

“…Glass fiber is a commercial lightweight (density ∼2.1 g cm –3 ) structural material with high mechanical strength and flexibility, as well as large specific surface area, and has been widely used as a reinforcing material for applications in aircraft, automobiles, etc . − Notably, glass fiber, with the main component being silica, is a good infrared radiation material originating from the Si–O bond vibration, showing high infrared emissivity around 0.8. , Considering the properties of graphene and glass fibers, the design of combining these two materials to develop an advanced dual-emitter infrared electrothermal material, graphene glass fiber (GGF), was proposed, where graphene works as the heating element and both components work as the radiating elements.…”