The invention discloses a SiO2 acid-base composite nanometer
coating with a porous structure and a preparation method thereof. The
coating consists of a multi-slit film with the thickness of 150-200 nm, and a substrate is covered with the multi-slit film, wherein the multi-slit film is formed by placing SiO2 nanometer chains containing mesopores between SiO2 nanoparticles which are distributed in a three-dimensional
net shape. The method includes the steps that separately prepared tetraethyl
silicate ethanol solutions are dropwise added into a mixed
aqueous solution and stirred for aging first, water and a
mixed solution of
ethanol and ethyl tetrasilicate are sequentially added into obtained SiO2 alkaline
sol after an
aqueous solution of
nitric acid is added dropwise into the SiO2 alkaline
sol, stirring is carried out to obtain acid-base composite
sol, and then
polyethylene glycol 300 is added into the acid-base composite sol and stirred for aging; the substrate is placed in the obtained sol for
film coating and then subjected to immersing, pulling,
film coating and air-
drying, and then an obtained film-coated substrate is subjected to annealing to obtain a target product. The nanometer
coating has good hydrophilicity and
wear resistance and high
light transmission performance and is extremely likely to be commercially used in the fields of
fog resistance, automatic cleaning, wide-spectrum reflection enhancement and the like in a wide range.