RESUMEN
Silica/cesium tungsten bronze (SiO2/Cs x WO3) composite micro-nano fiber membranes were prepared by the co-precursor electrostatic spinning method using cesium chloride, tungsten powder and tetraethyl orthosilicate as raw materials. TGA, XRD, FT-IR, XPS, SEM and ultraviolet-visible-near red spectrophotometry were used to analyze the thermal decomposition process, phase composition, microscopic morphology and near-infrared absorption properties of the product. Studies have shown that as the ratio of Cs/W of raw materials increases, the crystallinity of Cs x WO3 in the product increases first and then decreases. When n(Cs)/n(W) reaches 0.5, its crystallinity is the most complete; similarly, calcination also contributes to the crystallization of Cs0.33WO3, but high temperatures above 800 °C will also destroy its crystal structure. The study found that after calcination at 700 °C, the fiber membrane with a Cs/W atomic ratio of 0.5 has the best infrared absorption performance. The average absorbance of near-infrared light at 780-2500 nm is 1.5, which is 5.56 times that of the pure SiO2 fiber membrane. The tensile strength reaches 2.4 MPa, which can meet practical requirements. This research provides a basis for the development of flexible solar shading materials under complex outdoor conditions.
RESUMEN
Silica/titanium dioxide (SiO2/TiO2) composite nanofiber membranes with different TiO2 content were prepared with the technology of electrospinning using ethyl orthosilicate, butyl titanate and polyvinyl pyrrolidone as silicon titanium sources and spinning aids. TGA, XRD, SEM and FT-IR were used to analyze the thermal decomposition process, phase composition, microscopic morphology and infrared properties of the products. The study showed that with the increase of the calcination temperature, the TiO2 phase gradually changed from amorphous to anatase structure. Above 900 °C, a sample containing rutile TiO2 with a higher refractive index was obtained. Simultaneously, the continuity of the sample deteriorated, and the mechanical properties deteriorated. The study found that after calcination at 900 °C, the fiber membrane with a TiO2 content of 12% had the lowest cost and the best overall performance, with tensile strength being 3.09 MPa, and thermal conductivity at 500 °C being 0.0899 W m-1 K-1, which is 20% lower than that of pure SiO2 fiber membrane. This research provides a reference for the development of high temperature insulation materials with good flexibility.