Two exfoliation approaches for organic layered compounds: hydrophilic and hydrophobic polydiacetylene nanosheets

Abstract

Two versatile exfoliation approaches generate both hydrophilic and hydrophobic nanosheets from an organic layered compound.

Colloidally Stable Monolayer Nanosheets with Colorimetric Responses

“…The high‐resolution TEM image and corresponding selected‐area electron diffraction (SAED) pattern (Figure c) reveal that the nanosheets are noncrystalline, which is also supported by powder X‐ray diffraction (XRD) (Figure S9, Supporting Information). As reported, the diffraction peaks of PDA stemming from its layered bulk crystal structure will disappear as PDA is in the form of monolayer nanosheets . Small‐angle X‐ray scattering (SAXS) was performed to analyze the thickness of PDA‐EDMA‐TMG nanosheet in solution.…”

“…Nonetheless, despite the discovery of PDA Langmuir–Blodgett monolayer films assembled at air–liquid interfaces for decades of years as well as the easy intercalation of layered diacetylene crystals with various metal ions or amines, the fabrication of colloidally stable few‐layer PDA nanosheets in aqueous media is scarcely reported so far. Recently, Oaki and co‐workers prepared ultrathin hydrophilic and hydrophobic PDA nanosheets by exfoliating layered 10,12‐pentacosadiynoic acid (PCDA) crystals in both aqueous solution and toluene; however, the PDA nanosheets obtained by this method are very fragmented (lateral sizes less than 1 µm) with neither monolayer structure nor colorimetric responses . Therefore, it is still highly desirable but remains an urgent challenge to prepare colloidally stable monolayer organic 2D nanosheets with colorimetric responses.…”

“…Recently, Oaki and coworkers prepared ultrathin hydrophilic and hydrophobic PDA nanosheets by exfoliating layered 10,12-pentacosadiynoic acid (PCDA) crystals in both aqueous solution and toluene; however, the PDA nanosheets obtained by this method are very fragmented (lateral sizes less than 1 µm) with neither monolayer structure nor colorimetric responses. [28] Therefore, it is still highly desirable but remains an urgent challenge to prepare colloidally stable monolayer organic 2D nanosheets with colorimetric responses.Herein, we report for the first time colloidally dispersed chromic monolayer nanosheets based on PDA with large lateral Despite the discovery of chromogenic-layered materials for decades of years, fabrication of colloidally stable monolayer organic 2D nanosheets in aqueous media with colorimetric responses is still challenging. Herein reported is the first solution synthesis of chromic monolayer nanosheets via the topochemical polymerization of self-assembled amphiphilic diacetylenes in aqueous media.…”

“…Recently, Oaki and coworkers prepared ultrathin hydrophilic and hydrophobic PDA nanosheets by exfoliating layered 10,12-pentacosadiynoic acid (PCDA) crystals in both aqueous solution and toluene; however, the PDA nanosheets obtained by this method are very fragmented (lateral sizes less than 1 µm) with neither monolayer structure nor colorimetric responses. [28] Therefore, it is still highly desirable but remains an urgent challenge to prepare colloidally stable monolayer organic 2D nanosheets with colorimetric responses.…”

Exfoliating a CdII–Purine Framework: Conversion of Nanosheets‐to‐Nanofibers and Studies of Elastic and Capacitive Properties

“…The different layers in a layered material are stacked and held by weak van der Waal forces, hydrogen bonding, and non‐covalent interactions. These stabilizing intermolecular forces could be disrupted by various methods, such as sonication‐assisted, surfactant‐assisted, mechanical, chemical, and ion‐induced intercalation . Exfoliation affords 2D nanosheets of atomic thicknesses (<10 nm) and with high aspect ratios.…”