Polymorphic tin dioxide synthesis via sol–gel mineralization of ethyl–cyanoethyl cellulose lyotropic liquid crystals

The polymorphic tin dioxide (SnO₂) was synthesized by calcinating the sol–gel mineralized hybrid of the tin source solution (SnCl₄/ethanol/H₂O) and the lyotropic liquid crystal of ethyl–cyanoethyl cellulose((E-CE)C)/acrylic acid (AA). The sub-micrometer SnO₂ spheres with bimodal distribution at 370 and 860 nm were obtained after calcinating the hybrid at 400°C for 5 h. When the hybrid was exposed to ultraviolet first and then calcinated the flying-saucer-like SnO₂ was formed. The exposure time was found to influence the morphology of the as-prepared SnO₂. Except for the spherical and the flying-saucer-like SnO₂, a small amount of well-developed polyhedral SnO₂ was also observed in the as-prepared samples. On this basis, the lyotropic liquid crystal of (E-CE)C/AA afforded a novel route to obtain polymorphic SnO₂.