Method for producing a heat insulating material composed of a hydrophobic aerogel and the application thereof

A method for producing a heat insulating material composed of a hydrophobic aerogel, comprising:

• (1) mixing step:
• adding a siloxane compound, an inorganic binder solution and a chloride-ion free surfactant into a mixing solvent in order to be dispersed in the mixing solvent to form a uniform mixing solution;
• wherein based on total volume of the mixing solution, a concentration of the inorganic binder solution is 0.05 to 3.0 vol %, and a concentration of the chloride-ion free surfactant is 0.01 to 0.5 vol %;
• wherein the inorganic binder comprises:
• zirconium phosphate, phosphoric acid-copper oxide, or copper-containing oxide;
• (2) hydrolysis step:
• adding an acid catalyst solution into the mixing solution to perform a hydrolysis reaction;
• (3) condensation step:
• adding a basic catalyst solution into the mixing solution after the hydrolysis to perform a condensation reaction;
• wherein the siloxane compound forms stable hydrogel starting particles of a particle size of approximately 5 to 10 nanometers, followed by bonding with each other to grow to hydrogel secondary particles of a particle size of 100 to 1000 nanometers, thereby causing a viscosity of the mixing solution to increase in order to form a solution-like sol;
• finally, the hydrogel secondary particles form a wet gel of a network structure;
• (4) aging step:
• performing aging on the wet gel of the network structure under a specific temperature range of 50 to 95° C. in order to form a more stable gel structure;
• and
• (5) drying step:
• under a normal pressure performing evaporation and drying on the gel structure to remove the solvent;
• during the drying step, water molecules in the gel structure is allowed to escape slowly under an environment of approximately 50 to 90° C., followed by performing drying under a high temperature of 90 to 150° C., in order to obtain an insulating material composed of a hydrophobic aerogel;
• wherein the method does not include a solvent replacement step and a water washing step.