Preparation method of high-efficiency gel for seawater desalination

A preparation method of a gel, comprising:

• Step 1, add 2-10 mg/ml dopamine hydrochloride solution to 0.2-1 wt % ammonia solution to prepare dopamine aqueous solution, and add 0.1-0.5 g carnauba to 100 ml limonene to prepare carnauba wax solution, and prepare agar aqueous solution;
• Step 2, heat the agar aqueous solution prepared in step 1, then pour it into a polystyrene mold and cool it down to room temperature to form a gel, place the gel at 4° C. for 24 hours to age the gel, then freeze it in liquid nitrogen for 3-6 hours, and then place the gel at −18° C. for 12 hours to prevent cracking due to excessive temperature difference, and then thaw at room temperature;
• Step 3, soak the thawed gel prepared in step 2 in the dopamine aqueous solution for 24hours, and in-situ polymerize dopamine on the surface of the gel to generate a light-to-heat conversion material polydopamine;
• Step 4, soak the gel obtained in step 3 in an ethanol solution to change liquid;
• Step 5, soak the gel obtained in step 4 in the carnauba wax solution, and then dry it under normal pressure to obtain photothermal aerogel.