Density controlled oil uptake and beyond: from carbon nanotubes to graphene nanoribbon aerogels

Abstract

Large-scale manipulation of the density (from 2.5 to 1327 mg cm -3 ) and wettability of carbonbased aerogels have been realized by delicately modulating the gelation, drying and post treatment processes. An unexpected "Janus face" effect of pyrrole was revealed in the fabricating process. Pyrrole acts as a "spacer" at relatively low concentrations (< ca. 5 vol%), resulting in a decrease of the aerogel density; however, "linker" behaviour appears at higher concentrations (> ca. 5 vol%), leading to an increase of the aerogel density. By systematic studies, the oil adsorption capacity of aerogels has been correlated to the aerogel density and surface wettability, which can guide the production of highly efficient sorbents. For example, polydimethylsiloxane modified graphene nanoribbons aerogel with a density of 2.5 mg cm -3 was prepared and showed a remarkable adsorption capacity of up to 302 times for phenixin and 121 times for n-hexane its own weight, much higher than that of most carbonaceous sorbents previously reported. Furthermore, a proof-of-concept aerogel-based floating-type densitometer has also been proposed to expand the potential applications of aerogels.The relationship of oil adsorption capacity and the aerogel parameters has been fabricated by delicately manipulating the density of carbon aerogels.

3D Self‐Supporting Porous Magnetic Assemblies for Water Remediation and Beyond

“…In this way, the density of resultant materials increased, which has been proved to be unfavorable to acquire high adsorption capacity. [15] Actually, the average maximum oil adsorption capacity of those 3D-SPMAs is below 30 times weight gain, which is far lower than normal 3D-SPAs. Although magnetic CNT sponges, [41] carbon fibers based aerogels, [112] and ultralight Fe 2 O 3 /C foams [38] showed relatively higher capacity of approximately 45 to 60, 30 to 70, and 50 to 103 times weight gain, respectively.…”

“…In the first class, 3D-HMA were obtained by the post-modification of as-prepared 3D-S PMAs. [4,15,33,34,[38][39][40]44,93,104,106,113] For example, Li et al [104] have introduced octadecyl chains on the surface of as-prepared Figure 11. a) Schematic illustration of fabrication of magnetic p(AMPS) hydrogel composite and its application for removing toxic metals.…”

Recent Development of Advanced Materials with Special Wettability for Selective Oil/Water Separation

“…By combining the robust mechanical strength of CNTs and large surface area of graphene, CNT/graphene composites have also been prepared with much improved performance. [115][116][117] For example, Sun et al fabricated ultrafl yweight aerogels (UFAs) through the "sol-cryo" method using CNTs and giant graphene sheets. [ 117 ] The UFA exhibited an extremely low density (0.16 mg cm −3 ) and high porosity of around 99.9%, resulting in an unprecedented high oil uptake capacity of over 900 times of its own weight.…”

Advanced Sorbents for Oil‐Spill Cleanup: Recent Advances and Future Perspectives

“…Because of their intrinsic hydrophobic property, carbon materials have potential applications in the field of oil‐spill cleanup. Over the past few years, carbon‐based oil sorbents have been extended from traditional activated charcoal, carbon microbelts,[12b] and graphite to recently developed nanostructured carbons such as carbon nanoparticles, carbon soot, carbon nanofibers (CNFs), graphene, and CNTs . By direct pyrolysis of certain types of biomass from nature, nanostructured carbon with hydrophobic properties can be easily obtained .…”