Abstract: This paper dealt with in detail the drying-solidification process, contraction and weight-loss
mechanisms, skeleton nanostructures and its evolution trends with temperature increasing for SnO₂ gel system within 20～700℃
heat-treatment interval by TG-DTA, BET-N₂ adsorption, and X-ray diffraction three measuring methods, and further covered with the influences of doping Sb
addition amounts, catalysts and solvents needed in sol stage on drying process and nanostructure of SnO₂ gels. Based on the measurements and
analysis, it is shown that SnO₂ gels are of porous nanostructure of size 1～15nm, in good agreement with Sherer’s Cylinder Skeleton Model, and drying solidification
includes three evolution stages: 20～200℃, 200～550℃ and >550℃, in which the desorption of solvents on the surfaces of gel skeleton,
break-up and oxidation of --acac ring chelated on Sn atom, structural relaxion of gel chain net and gel skeleton crystallization are responsible for the
weight-loss, contraction and solidification of gels, as temperature increases, the nano-skeleton coarsens and enlarges but keeps its radium-length ratio unchanged,

Key words: SnO₂ gels, drying-solidification process, nanostructure, cylinder model