Preparation method of layered double hydroxide polyacrylamide nano-composite hydrogel

The invention relates to the technical field of preparation of high-molecular polymers for oil fields, and provides a layered double hydroxide polyacrylamide nano-composite hydrogel preparation method, which comprises: mixing cobalt nitrate, aluminum nitrate and urea, heating, carrying out in-situ synthesis to obtain a cobalt-aluminum layered double hydroxide sol, irradiating with red laser to generate a Tyndall effect, and drying to obtain the layered double hydroxide polyacrylamide nano-composite hydrogel. Reducing the temperature of the system, and adding an anti-settling aid before a bright passage in the cobalt-aluminum layered double hydroxide sol disappears, so as to prepare the stable cobalt-aluminum layered double hydroxide sol; adding the polymer hydrogel as a cross-linking agent into acrylamide, stirring, introducing inert gas, adding an initiator, and polymerizing in an inert atmosphere to obtain polymer hydrogel; and finally, carrying out post-treatment, so as to obtain the layered double hydroxi