Thorium dioxide(ThO_(2))fibers exhibit exceptional structural stability,low density and superior flexibility,coupled with a remarkably high melting point,positioning them as promising candidates for thermal protection...Thorium dioxide(ThO_(2))fibers exhibit exceptional structural stability,low density and superior flexibility,coupled with a remarkably high melting point,positioning them as promising candidates for thermal protection applications.Additionally,their commendable secondary processing characteristics enable the development of diverse composite materials when integrated with other materials,significantly broadening the potential utilization of ThO_(2)materials and thorium resources in industrial fields.In this work,the ThO_(2)fiber was fabricated by the sol-gel precursor method,and the precursor with good spinnability and excellent stability was synthesized for the first time.The ThO_(2)fiber with a mean diameter of 868 nm is both highly flexible and strong(max.tensile strength 2.21 MPa),capable of bending freely across a wide temperature range from-196℃(in liquid nitrogen)to 1200℃.Meanwhile,it exhibits excellent temperature stability and heat insulation properties.The ThO_(2)nanofiber membranes with layered structure have low density(32-37 mg·cm^(-3)),low thermal conductivity(27.3-30.1 mW·m^(-1)·K^(-1)@25℃).The ThO_(2)nanofiber membranes with 15 mm thickness can reduce the temperature from 1200 to 282℃and maintain a high aspect ratio and bendability after 1200℃@90 min.The results show that the ThO_(2)fiber can be used as a new kind of high-temperature resistant material.展开更多
In this work, water-based precursor solutions suitable for dip-coating of thick La2Zr2O7 （LZO） buffer layers for coated conductors on Ni-5%W substrates with an inclusion of polymeric polyvinyl pyrrolidone were devel...In this work, water-based precursor solutions suitable for dip-coating of thick La2Zr2O7 （LZO） buffer layers for coated conductors on Ni-5%W substrates with an inclusion of polymeric polyvinyl pyrrolidone were developed. The effect of varying percentage of the polymer addition on the preparation of the deposited films with maximum crack-free thickness was investigated. This novel water-based chemical solution deposition method involving polymers in two different chelate-chemistry compositions revealed the possibility to grow single, crack-free layers with thicknesses ranging from 140 to 280 nm, with good crystallinity and epitaxial growth. The effect of increasing polymer concentrations on the morphology and the structure of the films was studied. The appropriate buffer layer action of the films in preventing Ni diffusion was studied by X-ray photoelectron spectroscopy.展开更多
基金supported by the National Natural Science Foundation of China(No.52202090)the Fundamental Research Funds for the Central Universities(No.2082019014).
文摘Thorium dioxide(ThO_(2))fibers exhibit exceptional structural stability,low density and superior flexibility,coupled with a remarkably high melting point,positioning them as promising candidates for thermal protection applications.Additionally,their commendable secondary processing characteristics enable the development of diverse composite materials when integrated with other materials,significantly broadening the potential utilization of ThO_(2)materials and thorium resources in industrial fields.In this work,the ThO_(2)fiber was fabricated by the sol-gel precursor method,and the precursor with good spinnability and excellent stability was synthesized for the first time.The ThO_(2)fiber with a mean diameter of 868 nm is both highly flexible and strong(max.tensile strength 2.21 MPa),capable of bending freely across a wide temperature range from-196℃(in liquid nitrogen)to 1200℃.Meanwhile,it exhibits excellent temperature stability and heat insulation properties.The ThO_(2)nanofiber membranes with layered structure have low density(32-37 mg·cm^(-3)),low thermal conductivity(27.3-30.1 mW·m^(-1)·K^(-1)@25℃).The ThO_(2)nanofiber membranes with 15 mm thickness can reduce the temperature from 1200 to 282℃and maintain a high aspect ratio and bendability after 1200℃@90 min.The results show that the ThO_(2)fiber can be used as a new kind of high-temperature resistant material.
基金funding under the project grants P2/00/03 (CHEMAT)IAP/VI-17(INANOMAT) and FP7-NMP-2007- SMALL-1 Grant No.205854(EFECTS)
文摘In this work, water-based precursor solutions suitable for dip-coating of thick La2Zr2O7 （LZO） buffer layers for coated conductors on Ni-5%W substrates with an inclusion of polymeric polyvinyl pyrrolidone were developed. The effect of varying percentage of the polymer addition on the preparation of the deposited films with maximum crack-free thickness was investigated. This novel water-based chemical solution deposition method involving polymers in two different chelate-chemistry compositions revealed the possibility to grow single, crack-free layers with thicknesses ranging from 140 to 280 nm, with good crystallinity and epitaxial growth. The effect of increasing polymer concentrations on the morphology and the structure of the films was studied. The appropriate buffer layer action of the films in preventing Ni diffusion was studied by X-ray photoelectron spectroscopy.
