Papers

Jan, 2022

Oxidation-degree-dependent moisture-induced actuation of a graphene oxide film

RSC ADVANCES
  • Waka Nakanishi
  • ,
  • Yoshihiro Yamauchi
  • ,
  • Yuta Nishina
  • ,
  • Masafumi Yoshio
  • ,
  • Masayuki Takeuchi

Volume
12
Number
6
First page
3372
Last page
3379
Language
English
Publishing type
Research paper (scientific journal)
DOI
10.1039/d1ra07773b
Publisher
ROYAL SOC CHEMISTRY

Multilayered films prepared from graphene oxide (GO) subjected to a single oxidation process (1GO) can actuate in response to moisture, whereas those prepared from GO subjected to two oxidation processes (2GO) lose this ability. To elucidate the origin of this difference, the structures and properties of various multilayered films and their contents were analyzed. According to atomic force microscopy images, the lateral size of the GO monolayer in 2GO (2.0 +/- 0.4 mu m) was smaller than that in 1GO (3.2 +/- 0.4 mu m), although this size difference did not affect actuation. Scanning electron microscopy images of the cross sections of both films showed fine multilayered structures and X-ray diffraction measurements showed the moisture sensitive reversible change in the interlayer distances for both films. Both films adsorbed 30 wt% moisture in 60 s with different water contents at the bottom moist sides and top air sides of the films. Nanoindentation experiments showed hardness values (1GO: 156 +/- 67 MPa; 2GO: 189 +/- 97 MPa) and elastic modulus values (1GO: 4.7 +/- 1.7 GPa; 2GO: 5.8 +/- 3.2 GPa) typical of GO, with no substantial difference between the films. On the contrary, the 1GO film bent when subjected to a weight equal to its own weight, whereas the 2GO film did not. Such differences in the macroscopic hardness of GO films can affect their moisture-induced actuation ability.

Link information
DOI
https://doi.org/10.1039/d1ra07773b
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000746889600001&DestApp=WOS_CPL
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85124104830&origin=inward Open access
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85124104830&origin=inward
ID information
  • DOI : 10.1039/d1ra07773b
  • eISSN : 2046-2069
  • SCOPUS ID : 85124104830
  • Web of Science ID : WOS:000746889600001

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