Modified silicon dioxide aerogel microsphere thermal-insulation coating

The invention discloses a thermal-insulation coating by taking hydrophobic silicon dioxide aerogel microspheres as thermal-insulation packing. The coating is prepared by the following main steps: preparing the hydrophobic silicon dioxide aerogel microspheres; and mixing the prepared hydrophobic silicon dioxide aerogel microspheres and a polymer emulsion to prepare the thermal-insulation coating. Hydrophobic modification of the silicon dioxide aerogel microspheres includes the following two modes: in one mode, silicon dioxide wet-gel microspheres are modified by adopting halogenated hydrocarbon and in the other mode, alkoxy silane, silazane or siloxane is added into a mixed solution in a sol preparing stage. When the coating is prepared, a surfactant is added, so that the compatibility between the hydrophobic silicon dioxide aerogel microspheres and the polymer emulsion can be improved, the dispersibility of the microspheres in the coating can be improved, the coating quality can be improved, and the thermal-insulation performance of the coating can be improved.