Phenol‐Derived Carbon Sealant Inspired by a Coalification Process

Abstract

Recently, emerging functions utilizing phenolic molecules, such as surface functionalizing agents or bioadhesives, have attracted significant interest. However, the most important role of phenolic compounds is to produce carbonized plant matter called “coal”, which is widely used as an energy source in nearly all countries. Coalification is a long‐term, high‐temperature process in which phenols are converted into conducting carbonized matter. This study focuses on mimicking coalification processes to create conducting sealants from non‐conducting phenolic compounds by heat treatment. We demonstrate that a phenolic adhesive, tri‐hydroxybenzene (known as pyrogallol), and polyethylenimine mixture initially acts as an adhesive sealant that can be converted to a conducting carbon sealing material. The conductivity of the phenolic sealant is about 850 Ω−1 cm−1, which is an approximately two‐fold enhancement of the performance of carbon matter. Applications of the biomimetic adhesives described herein include conducting defect sealants in carbon nanomaterials and conducting binders for metal/carbon or ceramic/carbon composites.

Strategic Advances in Spatiotemporal Control of Bioinspired Phenolic Chemistries in Materials Science

“…[279] Polyphenol-amine copolymerized networks are instrumental to the development of adhesives and catalysts with durable properties. [51,127] On the other hand, there is a paucity of work that mirrors Nature's strategy of synergizing phenolic chemistries with sophisticated multiscale architectures. [6] In other words, it is highly desirable to consider topology and microstructure engineering of phenolic materials to amplify the performances and add functionality.…”

“…Reproduced with permission. [ 51 ] Copyright 2020, Wiley. d) Polymeric entanglement of PG/PEI network on surfaces of silica particles.…”

“…[ 95 ] Recently, Lee and co‐workers demonstrated that atmospheric oxygen is effective to trigger a rapid oxidative crosslinking between PG and polyethylenimine (PEI), leading to the formation of robust adhesive self‐sealing PG/PEI films (Figure 4E, c). [ 51 ] By further inclusion of oxygen‐delivering silica agglomerates into a polyphenol–PEI copolymerization system, the same group prepared superglues with impressive mechanical properties and versatile adhesive properties. [ 127 ] The synergy of polyphenol with amine‐rich polymer resulted in strong mechanical properties and versatile adhesive properties, showing new prospects in the development of gels and carbon materials.…”

“…In these cases, polyphenol–amine copolymerized networks would be a more suitable priming structure than pure polyphenols/MPNs for secondary functionalization. [ 51,127,274 ] For example, Lee group has very recently developed a polymeric superglue by copolymerization of a polyphenol (PG) and an amine‐containing polymer (PEI). [ 127 ] The observed superglue performances are majorly ascribed to the formation of phenol–amine crosslink networks, as well as adhesiveness from residual phenolic groups.…”

“…Finally, the postpolymerization control of phenolic chemistries offers a second opportunity for tailoring material properties. [49] The surface moieties or bulk properties of catechol-based materials can be post-modified by grafting, [2] doping, [49] etching, [50] carbonization, [51] etc. to satisfy a particular function demand, including roughness, hydrophilia, and catalytic and biological properties, etc.…”