Characterization and stability of innovative modified nanosilica-resin composite coating: Subjected to mechanical, chemical, and cryogenic attack

Abstract

It is crucial to enhance the concrete permeation resistance to liquefied natural gas (LNG) by utilizing a functional coating having excellent cryogenic stability. In this study, a novel method was provided to prepare a modified nanosilica-resin composite coating with excellent oleophobicity and permeation resistance to small molecule alkane oils. The properties of this coating were comprehensively characterized in terms of wettability test, mechanical stability test, chemical stability test, and oil impermeability test. Additionally, its cryogenic stability was also evaluated through the above methodologies. The results showed that the contact angle of mineral oil on the coating exceeds 150°, with a contact angle loss rate of only 2.98 % after 100 cycles of sandpaper abrasion. The contact angle remained above 130° after 24-h immersion in HCl, NaOH, and NaCl solutions, indicating its excellent chemical stability. Upon application, the coating significantly reduces the oil absorption rate of concrete exposed to small-molecule alkane oil by >80 %. More significantly, the contact angle of the coating remained above 150° even after cryogenic treatment, exhibiting a minimal contact angle loss rate of just 2.77 % following 100 cycles of sandpaper abrasion, demonstrating excellent cryogenic stability. The scanning electron microscope and X-ray photoelectron spectrometer results showed that the coating can maintain micro-nano rough structure and chemical structure of fluorine-containing low surface energy functional groups after cryogenic treatment, attributing to its remarkable stability. These findings underscore the novel coating's substantial potential for application potential in various cryogenic industrial fields.