Tough strippable hydrogel films based on acrylic Acid/Acrylamide/Zirconyl chloride for surface radioactive decontamination at low temperatures

Strippable films are extensively utilised for the decontamination of radioactive surfaces because of their cost-effectiveness, ease of operation, and minimal liquid waste. However, traditional strippable detergents are formulated for use at normal ambient temperatures and typically lose their efficacy at low temperatures because of poor performance or excessively long film-forming time. In this study, we have developed an anti-freezing and sprayable AMZW detergent based on acrylic acid (AA), acrylamide (AM), zirconyl chloride octahydrate (ZrOCl 2 ·8H 2 O), and water (H 2 O), which possesses a freezing point of approximately −34 ℃ due to the solvation interaction between Zr 4+ and H 2 O. Even at temperatures as low as −25 ℃, the AMZW detergent can be easily sprayed using a conventional apparatus and rapidly cured into a strippable hydrogel film under irradiation by 365 nm UV LED light (LED@365 nm), household LED panel light, or sunlight. The coordination bond formed between Zr 4+ and the carboxyl group of the polymer chain imparts excellent mechanical properties to the hydrogel while the carboxyl group can complex with uranyl nitrate hexahydrate (UO 2 (NO 3 ) 2 ·6H 2 O)—a radioactive simulant. As a result, the strippable hydrogel film demonstrates high tensile strength (6.1 ∼ 19.3 MPa), excellent flexibility (elongation of 90 ∼ 855 %), moderate peel strength (0.05 ∼ 3 N/cm, room temperature (RT)), and high decontamination efficiency (>91.6 % on stainless steel and glass; >81.3 % on concrete) over a wide range of temperatures (−25 ∼ 25 ℃). This work presents a novel approach for producing anti-freezing, fast-forming, flexible, and high-strength strippable hydrogel films for surface radioactive decontamination at low temperatures.