This disclosure relates to liquid dispersion compositions that are suitable to provide absorbent materials (e.g., an absorbent coating), and methods of preparing the compositions and absorbent materials thereof.

A method for preparing a solid amine adsorbent of CO.sub.2 includes introducing a gas mixture containing 10 vol. % to 50 vol. % of CO.sub.2 is introduced into a sodium aluminate solution having a concentration in a range of 10 g/L to 100 g/L at room temperature to obtain a reaction solution. This occurs continuously until a pH value of the reaction solution is lowered to 9.5 to 9.8 to obtain a product solution containing a precipitate. The precipitate is filtered and washed. The filtered and washed precipitate is mixed with an organic alcohol at a mass ratio of 1:5 to 1:30 to obtain a suspension. The suspension is heated to an azeotropic point of water and the organic alcohol, and evaporated, boiled, and refluxed to obtain pore-enlarged pseudo boehmite. This is calcined to obtain aluminum oxide powder. The aluminum oxide powder is impregnated in an organic amine solution and dried.