Nanoporous Asphalt-Based Activated Carbon Prepared from Emulsified Asphalt and Graphene Oxide as High-Thermal-Conducting Adsorbers for n-Hexane Vapor Recovery

Abstract

Because of the low thermal conductivity of activated carbon, local overheating often occurs during the adsorption process for volatile organic compounds (VOCs), resulting in a low adsorption efficiency, potential fire hazard, etc. Asphalt-based activated carbon (A-AC) was prepared from emulsified asphalt, and graphene oxide (GO) was evenly dispersed in A-AC in situ to prepare a nanoporous carbon with asphalt/GO as a high-thermal-conducting adsorber for n-hexane vapor recovery. Then this study systematically discusses the effects of GO on the specific surface area, pore size distribution, thermodynamic properties of A-AC, and the adsorption/ desorption properties of n-hexane vapor. The results show that the addition of an appropriate amount of GO is beneficial to the formation of a cross-linked structure in the A-AC during the activation process. When the optimized amount of GO is 1.0 wt % (labeled as A-AC/GO-1.0), both the specific surface area and micropore volume reach the maximum, which are 1662 m 2 •g −1 and 0.49 cm 3 •g −1 , respectively. More importantly, the thermal conductivity of A-AC/GO-1.0 is 2 times that of A-AC. In addition, the A-AC/GO-1.0 material has a good adsorption capacity for n-hexane vapor, which is 1.76 times for A-AC. It can also retain a good regeneration performance after a dynamic adsorption experiment. Therefore, as a promising material, A-AC/GO will break through the technological bottleneck of the adsorption/desorption of activated carbon, such as low adsorption capacity owing to the high adsorption heat effect, difficult desorption and regeneration, and short life.

Preparation of an Activated Carbon Composite with High Thermal Conductivity Based on Emulsified Asphalt and Carbon Nanotubes and its Adsorption Performance for n‐Hexane

“… Prepared CNTs dispersions with different mass fractions (the amount of dispersant polyvinylpyrrolidone PVP is 5 % of the mass of CNTs) and prepared aqueous KOH solution simultaneously. Weighed a certain mass of emulsified asphalt (emulsified asphalt is prepared by asphalt, AEO‐9, and deionized water at 60 °C), [32] which was heated and stirred to a dense state. Then slowly poured CNTs dispersion and KOH aqueous solution into the emulsified asphalt in turn and continued to stir for 40 min to mix well (The mass ratio of asphalt to KOH is 1 : 4.…”

“…(2) Weighed a certain mass of emulsified asphalt (emulsified asphalt is prepared by asphalt, AEO-9, and deionized water at 60 °C), [32] which was heated and stirred to a dense state. Then slowly poured CNTs dispersion and KOH aqueous solution into the emulsified asphalt in turn and continued to stir for 40 min to mix well (The mass ratio of asphalt to KOH is 1 : 4.).…”

Effects of mechanical properties of carbon-based nanocomposites on scaffolds for tissue engineering applications: a comprehensive review

“…20 For example, the combination of GO with other components makes it a strong adsorbent for the absorption and desorption of n-hexane vapor, which is due to both to the enhanced specic surface area and micropore volume of the composite. 21 In the aerospace industry, CNTs have been used as a mechanical performance modier due to their high specic surface area, mechanical strength, and inherent hardness. 22 One of the most important applications of carbon structures is to the improve mechanical properties of materials in tissue engineering.…”