posted on 2019-10-01, 11:03authored byWenliang Song, Yu Zhang, Anuraj Varyambath, Il Kim
Three-dimensional
hierarchical nanoporous polymers and carbon nanomaterials
with well-defined superstructures are of great interest for various
intelligent applications, whereas a facile and versatile approach
to access those materials with a high surface area, stable well-defined
morphology, and ordered pores still remains a significant challenge.
Herein, we report a self-regulated Lewis acid–base interaction-mediated
assembly strategy for the in situ synthesis of morphology-engineered
hyper-cross-linked porous polymers and carbon materials. A series
of functionalized aromatic compounds (FAC) is subjected to self-cross-linking via classic Friedel–Crafts chemistry to achieve stable
porous polymers with a high surface area. Varying the monomer/catalyst
combination had a dramatic effect on the acid–base interaction,
facilitating the tailoring of the self-assembled morphologies from
nanotubes to hollow nanospheres, and even nanosheets. A mechanistic
study showed that the byproducts generated during cross-linking orchestrate
the interactions between the catalyst (acid) and FAC (base) and simultaneously
drive the self-assembly to yield specific morphologies. Based on the
rigid hollow polymer framework and intrinsic hydroxyl functionality,
the hyper-cross-linked hollow nanospheres were easily transformed
to an acid-functionalized catalyst for efficient biodiesel production.
Moreover, high-quality porous carbonaceous nanocounterparts such as
carbon nanotubes, hollow carbon nanospheres, and carbon nanosheets
could also be produced by direct pyrolysis of the corresponding polymer
precursors. These findings may provide guidance for the facile design
of morphology-controlled functionalized polymers and carbon nanomaterials
for various applications.