Desenvolvimento de um coletor rotativo para uso em fiação por sopro em solução e produção de nanofibras alinhadas de sílica.

Abstract

Solution Blow Spinning (SBS) is a technique recently used in the production of nanometric and submicron fibers, however with few studies focused on the development of collector systems. Thus, this thesis aims to develop a rotary collector for use in solution spinning and silicon aligned nanofiber production. For the development of this work was designed and built prototypes of rotating collectors of the type strips (stems), looking for a collector that optimized the alignment and drying of the nanofibres The collector was applied in the collection of nanofibers of polymer, poly (vinyl alcohol) (PVA) and hybrid nanofiners PVA/TEOS, also being evaluated the alignment behavior of the ceramic silica nanofibers (SiO2) after firing hybrid nanofibers. For collection and alignment of the SiO2/PVA hybrid fibers, SiO2 and polymeric PVA by SBS ceramics collected on the collector surface, the collector velocity was varied, obtaining a range of tangential velocities at the point of collection from 1.035 to 5.175 km.h-1. For the collection of polymeric nanofibers and hybrid fibers, it was found that high tangential velocities from a boundary at the collection point tend to worsen the alignment of the collected fibers the thicker the layer of fibers deposited. The results show that aligned fibers of nanometric diameters can be obtained using the appropriate speed range, which can vary with the spinning time as a function of the thickness of the layer deposited in the collector. It has been found that about 62% of the fibers in the range of -10 ° and 10 ° and 81% of the fibers in the range of -20 ° and 20 ° for polymer fibers are possible. With respect to the hybrid fibers it has been found that it is possible to align about 63% of the fibers in the range of -10 ° and 10 ° and 80% of the fibers in the range of -20 ° and 20 ° for hybrid fibers; and about 62% of the fibers in the range of -10 ° and 10 ° and 80% of the fibers in the range of -20 ° and 20 ° for ceramic fibers.