Relationship between Spinning Aid Polyvinyl Alcohol and Morphology of Alumina Nanofibers via Electrospinning Method

Abstract Polyvinyl alcohol/alumina precursor solution was prepared using economical aluminum chlorohydrate as the aluminum precursor and water as the solvent. The precursor solution was subsequently employed in electrospinning process to yield alumina nanofibers. The relationship between various Polyvinyl alcohol factors, such as degree of hydrolysis, molecular weight and dosage, and morphology of alumina nanofibers via electrospinning method was studied. The Polyvinyl alcohol with a lower molecular weight was used, the precursor solution viscosity decreased, facilitating the finer alumina nanofibers. Conversely, higher molecular weights of Polyvinyl alcohol resulted in more viscous solution, giving rise to coarser fibers that were prone to breakage. Notably, when Polyvinyl alcohol model 1788, characterized by an alcohol alcoholysis degree of 88% and a molecular weight of approximately 75 000, was used as the spinning aid, the precursor solution displayed remarkable stability as Newtonian fluid behavior. When Polyvinyl alcohol of type 1788, 1799, 2488 and 3588 was used as spinning aid, the crystal grain sizes of the prepared alumina fibers were 27, 107, 68 and 144 nm, and the pore sizes of the fibers were 40, 90, 78 and 121 nm, respectively. It indicated that the pore size and grain size of the alumina fibers prepared electrospinning were relative with the molecular weight and alcohololysis degree of Polyvinyl alcohol As the dosage of Polyvinyl alcohol increases, the viscosity of the precursor solution increases, and the diameter of the final fiber increases. The 1788 precursor solution was also found to be optimal for the electrospinning process, enabling the production of a significant quantity of fibers with superior morphology. The resulting fibers possessed a diameter of 250 nm and were composed of the α-Al2O3 phase.