One-dimensional electrospun alumina borate ceramics: transformation from fiber-like structure to ribbon-like structure at the increased concentrations of precursor sol

In this work, one-dimensional alumina borate (AB) ceramics were prepared by a combination of electrospinning technique and sol-gel method. Basic aluminum acetate was used to prepare precursor sols with different concentrations. Polyvinyl pyrrolidone (PVP) was used as the polymer additive. The morphology of the electrospun ceramic products at increased sol concentrations was observed and the corresponding mechanism was discussed. With the sol concentration increased from 10% to 25%, the following results were found. For the spinning solutions, the viscosities and conductivities increased while the surface tension decreased accordingly. Electrospun precursors and calcined AB ceramics transformed from fiber-like structure to ribbon-like structure. The ribbon width and thickness increased accordingly. A new mechanism for the formation of the ribbon-like structure on the basis of force conditions on the cross-section of the whipping precursor fibers was established. The AB ribbons prepared at 1200 °C were made of Al₁₈B₄O₃₃ nanograins.