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Abstract Here it is shown that Ti3C2TxMXene flakes can be co‐assembled with recombinant silk fibroin in aqueous suspensions with silk fibroin nanolayers uniformly covering individual flakes. These bioencapsulated flakes evolve with time due to the gradual growth of silk bundles having β‐sheet secondary organization with unique nanofibrillar morphologies extending across flake edges and forming long fringes around individual MXene flakes. This spontaneous reorganization of recombinant silk suggests surface template‐initiated formation of intramolecular hydrogen bonding of silk backbones assisted by intermolecular electrostatic and hydrogen bonding with the MXene flake. The formation of dense and hydrophobic β‐sheets results in development of a protective shell that hinders the surface oxidation of Ti3C2Txin colloidal solution in water and significantly extends the storage life of the individual MXene flakes. Moreover, assembly into organized laminated composites with individual bioencapsulated flakes tightly interconnected via biopolymer bundles and hairs produces robust freestanding electrically conductive membranes with enhanced transport properties.
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Edge Capping of 2D‐MXene Sheets with Polyanionic Salts To Mitigate Oxidation in Aqueous Colloidal Suspensions
Abstract MXenes have shown promise in myriad applications, such as energy storage, catalysis, EMI shielding, among many others. However, MXene oxidation in aqueous colloidal suspensions when stored in water at ambient conditions remains a challenge. It is now shown that by simply capping the edges of individual MXene flakes, Ti3C2Tzand V2CTz, by polyanions such as polyphosphates, polysilicates or polyborates, it is possible to quite significantly reduce their propensity for oxidation even when held in aerated water for weeks. This breakthrough resulted from the realization that the edges of MXene sheets are positively charged. It is thus an example of selectively functionalizing the edges differently from the MXene sheet surfaces.
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- Award ID(s):
- 1740795
- PAR ID:
- 10110712
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 58
- Issue:
- 36
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 12655-12660
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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