Roll-to-roll fabrication of high surface area mesoporous carbon with process-tunable pore texture for optimization of adsorption capacity of bulky organic dyes

Abstract

Large-scale (multigram-to-kilogram) fabrication of soft-templated ordered mesoporous carbon (OMC) is enabled by roll-to-roll (R2R) processing via evaporation induced self assembly of Pluronic F127, oligomeric phenolic resin (resol), and tetraorthosilicate (TEOS) from ethanolic solution. The solution concentration, TEOS loading (etchable for microporous framework), and crosslinking temperature impact the pore structure. Here we demonstrate that mesoporous carbons with surface areas up to 2455 m2/g can be obtained under the proper processing conditions. Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS) and nitrogen adsorption–desorption isotherms reveal (i) suppressed framework shrinkage with increasing solution concentration during casting, (ii) improved long range order and higher surface area with increasing TEOS content up to 3:1 TEOS:resol, and (iii) enhanced porosity with crosslinking at 100 °C. These differences can be explained on the basis of block copolymer thermodynamics and mechanical reinforcement by silica. This family of OMCs are effective adsorbents for bulky aqueous organic dyes, such as methylene green (MG) and methyl blue (MB), with high adsorption capacities of 0.436 g MG/g OMC and 0.378 g MB/g OMC obtained. This R2R method provides a facile method to generate significant quantities of OMCs with tunable pore textures.