Study on modified MXene to increase the stability and decontamination properties of biomass-based antifreeze foam detergent

Abstract

In order to solve the problems of poor stability and low decontamination efficiency of foam detergent in the process of removing surface radioactive contamination in a low-temperature environment, MXene (Ti3C2Tx) was prepared by LiF/HCl etching, the MXene was modified by hydroxylation to obtain Alk-MXene, and the Alk-MXene was hydrophobically modified by octadecylamine (ODA) to obtain Alk-MXene@ODA. MXene, Alk-MXene, and Alk-MXene@ODA were characterized by SEM, XRD, FTIR, BET, and a contact angle measuring instrument. The effects of the addition of Alk-MXene@ODA on the foam stability, foaming ability of the foam detergent, foam liquid-film thickness, liquid-film decay rate, viscosity at the same shear rate, and spraying and wall-hanging properties were investigated. The decontamination properties of the Alk-MXene@ODA-stabilized biomass-based antifreeze foam detergent were also investigated. The results show that Alk-MXene has a large interlayer spacing, a large specific surface area, and abundant –OH on its surface. Alk-MXene exhibits full absorption of water, and the hydrophobicity of Alk-MXene@ODA after graft modification with ODA increased and the wetting contact angle increased to 89.07°. Via Alk-MXene@ODA synergistic foam stabilization, the drainage half-life of the foam increased from 40.81 min to 66.89 min, the average thickness of the foam liquid film increased from 47.065 µm to 53.162 µm, the liquid-film decay rate reduced from 0.956 µm/min to 0.544 µm/min, and the viscosity of the foam detergent solution increased at different shear rates. The foam detergent is sprayable, and the wall-hanging time can reach 80 min on a vertical tile surface. At −10 °C, the α decontamination factors of the Alk-MXene@ODA-stabilized biomass-based antifreeze foam detergent on glass, painted board, ceramic tile, and stainless steel were improved by 23.89, 23.77, 23.01, and 22.53, the β decontamination factors were improved by 15.48, 17.12, 15.03, and 14.42, respectively, relative to ordinary foam. The adsorption and coordination of uranyl ions with Alk-MXene@ODA promoted the improvement in the decontamination factor of the foam detergent. Alk-MXene@ODA combined with biomass-based antifreeze foam detergent can achieve dual functions of stabilizing foam and increasing decontamination efficiency. Biomass-based antifreeze foam detergent with increased stability and decontamination efficiency by Alk-MXene@ODA can efficiently and quickly remove surface radioactive contamination in a low-temperature environment.