Free‐Standing Molecularly Thin Amorphous Silica Nanosheets

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 19; no. 22; pp. e2300022 - n/a
• Main Authors: Yamamoto, Eisuke, Fujihara, Kosuke, Takezaki, Yuma, Ito, Kentaro, Shi, Yue, Kobayashi, Makoto, Osada, Minoru
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.06.2023
• Subjects: 2D assembly; Amorphous materials; amorphous silica; bottom‐up synthesis; Nanosheets; Nanotechnology; Silicon dioxide; solid surfactants; Thickness; Two dimensional materials; amorphous silica; 2D assembly; bottom-up synthesis; solid surfactants; nanosheets
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202300022

Recent progress in 2D materials has initiated new fields of molecularly thin amorphous materials with mysterious properties and structures. However, designed synthesis of molecularly thin amorphous silica still remains a challenge; whether free‐standing molecularly thin amorphous silica nanosheets can exist is unclear. Here, this issue is addressed by using a new chemical protocol; solid‐state surfactant lamellae with ordered alkyl‐chain arrangements can serve as superior templates guiding free‐standing amorphous silica nanosheets. Simple sonication of the lamellar hybrids allows exfoliation into monolayer amorphous silica nanosheets with 0.9 nm thickness. In addition, the nanosheets show the distinctive feature of high colloidal stability that enables atomic layer engineering of silica nanocoatings and dielectric nanofilms. The approach may shed new light on the properties and applications of old silica. A chemical protocol is established for free‐standing molecularly thin nanosheets; solid‐state surfactant lamellae can serve as templates guiding amorphous silica nanosheets. Delamination of the lamellar hybrids with ordered alkyl‐chain arrangement allows for free‐standing amorphous silica nanosheets with 0.9 nm in thickness. The nanosheets show high colloidal stability that enables atomic layer engineering of film with a highly insulating property.