1, prepare calcium chloride solution. Adding calcium chloride powder into distilled water and stirring evenly to obtain calcium chloride solution.
2. Cut the oxidized sodium alginate hydrogel into small pieces, add them into the calcium chloride solution and stir them evenly.
3. Let the mixture stand for a period of time to cross-link the gel.
4. Wash the gel with distilled water to remove excess calcium chloride.
5. Dry the gel in a dryer or ventilated drying room.