ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The effects of amino-modified graphene oxide on the water molecules diffusion and seawater barrier properties of DGEBA/3,3′-DDS epoxy resin: a molecular dynamics simulation

Youhui Xu, Jieyu Li, Hongbo Liang, Yuqing Xiong, Weisong Sun, Xiaoying Cao, Hongxia Cao, Fanting Kong, and Hengjiao Gao

School of Media Engineering, Lanzhou University of Arts and Science, Lanzhou, China

E-mail: xuyouhui@163.com

Received: 20 June 2023  Accepted: 23 October 2023

Abstract:

The process of water molecules diffusion in the DGEBA/3,3′-DDS epoxy resin coating with different content of NH-GO and barrier property in seawater environment were studied by the molecular dynamics simulation method. The results show that water molecules existed in epoxy resin internal micropores by the "bound water" with hydrogen bond and "free water" forms. The water molecules diffusion in the epoxy resin is mainly manifested as the free water diffusion process, and the transition from bound water to free water becomes more favorable as the temperature raised. As the temperature increases from 283 to 328 K, the corresponding diffusion coefficient of water molecules increases from 0.741 × 10⁻⁷ to 4.074 × 10⁻⁷ cm² s⁻¹. Due to the good sealing effect of NH-GO on the pores inside the epoxy resin, the diffusion coefficient of water molecules decreased gradually with NH-GO content increased and reached the minimum when the NH-GO increased to 4.2 wt% that the value decreases from 2.037 × 10⁻⁷ to 0.416 × 10⁻⁷ cm² s⁻¹. The NH-GO can further improve the cross-linking of epoxy resin coating and effectively prevent corrosive medium molecules from diffusing to the interface and inside the epoxy resin coating, resulting in the relatively best barrier property. The introduction of NH-GO helps to improve the barrier property and anti-corrosion property of epoxy resin coating.

Keywords: NH-GO; Molecular dynamics simulation; Water molecules diffusion; Corrosion resistance; Barrier property

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03174-8

Chemical Papers 78 (3) 1469–1479 (2024)