Ordered Nanoporous Carbons with Broadly Tunable Pore Size Using Bottlebrush Block Copolymer Templates

Abstract

We report the preparation of ordered porous carbon materials with tailored pore sizes selected between 16 and 108 nm using bottlebrush block copolymers (BBCPs) as templates. The nanoporous carbons are prepared via the cooperative assembly of polydimethylsiloxane-<i>block</i>-poly(ethylene oxide) (PDMS-<i>b</i>-PEO) BBCPs with phenol-formaldehyde resin yielding ordered precursor films, followed by carbonization. The assembly of PDMS-<i>b</i>-PEO BBCPs with the resin leads to films exhibiting a spherical morphology (PDMS as the minor domain) with uniform domain sizes between 18 and 150 nm in the bulk. The assembled PDMS sphere diameters scale linearly with BBCPs molecular weights, allowing precise control of domain size. Access to very large ordered domains is an enabling hallmark of BBCPs self-assembly, but reports of well-ordered spherical domains are not common. Carbonization of the ordered precursor films yields nanoporous carbon with uniform and tunable pore size. These nanoporous carbons are shown to exhibit excellent performance as supercapacitor electrodes with capacitance reaching up to 254 F g^-1 at a current density of 2 A g^-1.