Two-Dimensional Stacked Composites of Self-Assembled Alkane Layers and Graphene for Transparent Gas Barrier Films with Low Permeability

Yoon-Jeong Kim; Tae Hoon Seo; Yang Hui Kim; Eun-Kyung Suh; Sukang Bae; Jun Yeon Hwang; Jaewoo Kim; Youngjong Kang; Myung Jong Kim; Seokhoon Ahn

doi:10.1021/acs.nanolett.1c03761

Two-Dimensional Stacked Composites of Self-Assembled Alkane Layers and Graphene for Transparent Gas Barrier Films with Low Permeability

Nano Lett. 2022 Jan 12;22(1):286-293. doi: 10.1021/acs.nanolett.1c03761. Epub 2022 Jan 3.

Authors

Yoon-Jeong Kim^{1

2}, Tae Hoon Seo³, Yang Hui Kim¹, Eun-Kyung Suh, Sukang Bae¹, Jun Yeon Hwang¹, Jaewoo Kim¹, Youngjong Kang², Myung Jong Kim⁴, Seokhoon Ahn^{1

5}

Affiliations

¹ Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea.
² Department of Chemistry, Research Institute for Natural Sciences and Institute of Nano Science and Technology, Hanyang University, Seoul 04763, Republic of Korea.
³ Green Energy & Nano Technology R&D group, Korea Institute of Industrial Technology, Gwangju 61012, Republic of Korea.
⁴ Department of Chemistry, Gachon University, Gyeonggi-do 13120, Republic of Korea.
⁵ Department of Chemistry, Jeonbuk National University, Jeonbuk 54896, Republic of Korea.

PMID: 34978186
DOI: 10.1021/acs.nanolett.1c03761

Abstract

Self-assembled alkane layers are introduced between graphene layers to physically block nanometer size defects in graphene and lateral gas pathways between graphene layers. A well-defined hexatriacontane (HTC) monolayer on graphene could cover nanometer-size defects because of the flexible nature and strong intermolecular van der Waals interactions of alkane, despite the roughness of graphene. In addition, HTC multilayers between graphene layers greatly improve their adhesion. This indicates that HTC multilayers between graphene layers can effectively block the lateral pathway between graphene layers by filling open space with close-packed self-assembled alkanes. By these mechanisms, alternately stacked composites of graphene and self-assembled alkane layers greatly increase the gas-barrier property to a water vapor transmission rate (WVTR) as low as 1.2 × 10^-3 g/(m² day), whereas stacked graphene layers generally show a WVTR < 0.5 g/(m² day). Furthermore, the self-assembled alkane layers have superior crystallinity and wide bandgap, so they have little effect on the transmittance.

Keywords: chemical vapor deposition graphene; graphene gas barrier; scanning tunneling microscopy; self-assembly; two-dimensional crystal engineering.