The invention discloses a preparation method of a light high-strength hollow SiO2
aerogel composite board, which comprises the following steps: uniformly mixing
tetramethyl orthosilicate and
methanol, adjusting the pH value to be acidic, adding a
mixed solution of
ammonium fluoride and water, uniformly stirring, and hydrolyzing to obtain silica
sol; the preparation method comprises the following steps: putting a water-soluble
powder modifier into silica
sol, and dispersing under ultrasonic
waves to form a stable suspension; putting the suspension into a mold, adding a catalyst, uniformly stirring, and standing for reaction to obtain wet gel; putting the wet gel into a
mixed solution of water and
methanol, dissolving the
powder modifier in the wet gel by using ultrasonic
waves, and repeatedly replacing a soaking solution until the
powder modifier in the wet gel is completely dissolved; and after the wet gel becomes transparent, aging and
drying the wet gel in sequence to prepare the lightweight high-strength hollow SiO2
aerogel composite board. According to the invention, the one-time forming qualification rate of large-size
aerogel products is improved; a large-size hollow structure in the prepared hollow SiO2 aerogel composite board has a relatively strong
energy absorption effect, and the hollow SiO2 aerogel composite board is high in strength, light in weight and simple to manufacture.