Fabrication of YBa₂Cu₃O_7−δsuperconducting nanofibres by electrospinning

Abstract

YBa 2 Cu 3 O 7−δ superconducting nanofibres were successfully fabricated via the electrospinning method in combination with the sol-gel process. The solution was prepared by the sol-gel process with a homogeneous aqueous PVA solution containing Y, Ba, and Cu acetates. The viscosity of the precursor sol for electrospinning was controlled by the evaporation of solvent and a condensation reaction. The electrospun nanofibres were pyrolysed to remove PVA or volatile components, and then sintered to generate a superconducting phase. The critical transition temperature (T c ) of superconducting YBa 2 Cu 3 O 7−δ nanofibres was measured by DC susceptibility tests. By optimizing the electrospinning process and following heat treatments, superconducting YBa 2 Cu 3 O 7−δ nanofibres with a T c = 92.2 K could be produced.

Synergetic effects on the mechanical and fracture properties of epoxy composites with multiscale reinforcements: Carbon nanotubes and short carbon fibers

“…In general, the T g values indicated the start of large-scale motions of the molecular chains in the polymer materials. 38 For the treated SCF-reinforced specimen, the strong interactions of the SCFs and matrix tended to constrain the mobility of the polymer chains and, therefore, decreased T g . With respect to the MWNT-reinforced specimens, the increase in T g was believed to be the result of improved MWNT/EP interfacial interactions because the MWNTs used in this study were carboxylicfunctionalized.…”

Synthesis of Ultrafine High- <inline-formula> <tex-math notation="LaTeX">$T_{C}$</tex-math></inline-formula> Superconducting <inline-formula> <tex-math notation="LaTeX">$\mbox{GdBa}_2\mbox{Cu}_3\mbox{O}_{7\mbox{-}{x}}$</tex-math></inline-formula> Powder

“…This work demonstrates that by using the available and inexpensive benzene tricarboxylic acid, we can simply synthesize single-crystal nanowires of high-Tc superconductor in large quantities at low cost for industrial applications. It may be expected that a further optimization of the shape and particle size will result by changing the type and concentration of the utilized surfactant instead of using some complicated methods for synthesizing of nanowires such as electrodeposition [26] or electrospinning [27].…”

Broadband Dielectric Relaxation Spectroscopy of Functionalized Biobased Castor Oil Copolymer Thermosets

“…In general, three different polymerization mechanisms, namely thermal, [ 30,31 ] cationic, [32][33][34] and free radical [ 35,36 ] polymerization have been employed to synthesize a wide range of vegetable-oil-based polymers and copolymers with excellent thermal and mechanical properties. In addition to the just mentioned polymerization methods, ring-opening metathesis polymerization (ROMP) [37][38][39] and acyclic diene metathesis (ADMET) [ 40 ] are relatively new polymerization techniques that have also been used recently to synthesize novel vegetable-oilbased biopolymers. For instance, rubbery thermosets of modifi ed castor oil containing norbornene moieties and cyclooctene have been synthesized via ROMP.…”

“…[ 42 ] The glass-transition temperatures, T g , of the obtained biobased thermosets ranged from 80 to −29 °C based on the ratio of oil to DCPD as confi rmed by dynamic mechanical analysis (DMA) measurements. [ 39,41,42 ] The curing behavior of crosslinked polymers has been extensively investigated in the literature using a variety of experimental techniques, such as differential scanning calorimetry (DSC), [43][44][45] dynamic rheology, [46][47][48] broadband dielectric relaxation spectroscopy (BDRS), [49][50][51] and mechanical measurements. [52][53][54] BDRS is an accurate analytical technique that is typically used to monitor the dynamics of dipolar groups attached to the polymer molecular chains.…”