Centrifugal Spinning Research Papers - Academia.edu (original) (raw)

Spiropyran-functionalized poly(methyl methacrylate) (PMMA) Forcespinning® fibers were fabricated using a fiber making machine of our own design, employing 1 0 ,3 0 ,3 0-trimethyl-6-nitrospiro[1(2H)-benzopyran-2,2 0-indoline] (6-nitro... more

Spiropyran-functionalized poly(methyl methacrylate) (PMMA) Forcespinning® fibers were fabricated using a fiber making machine of our own design, employing 1 0 ,3 0 ,3 0-trimethyl-6-nitrospiro[1(2H)-benzopyran-2,2 0-indoline] (6-nitro BIPS) as the spiropyran. The effects of the polymer solution concentration (and hence the viscosity), the spinneret rotational rate, and the internal needle diameter on the formation and morphology of the fibers were examined, using scanning electron microscopy. A rotational speed of 3000 rpm and an internal nozzle diameter of 0.35 mm (23 G) in conjunction with a polymer concentration of 15 wt% produced 6-nitro BIPS/PMMA Forcespinning fibers having a smooth morphology with no beads. The photochromic properties of the resultant fibers were characterized by reflectance spectroscopy using the Kubelka–Munk function, fluorescence excitation emission matrix (EEM) analysis, and Raman spectroscopy. The thermal decoloration dynamics of the 6-nitro BIPS in the PMMA fibers were in good agreement with the properties observed in films. These results suggest that 6-nitro BIPS and other spiropyran dyes have significant potential as probes to assess the structures of micro/nanofibers.

With a worldwide ever increasing demand for metals, particularly for the manufacture of electronics and batteries, there is not only a concurrent need to recover these materials from their subsequent waste streams but also a need to make... more

With a worldwide ever increasing demand for metals, particularly for the manufacture of electronics and batteries, there is not only a concurrent need to recover these materials from their subsequent waste streams but also a need to make advancements to do this via development of more efficient and eco-friendly processes for metal recovery; solid-phase extraction can be considered a promising alternative to conventional processes. This work studied the production of novel nanofibers modified with Cyanex 272 and their application in the recovery of cobalt present in aqueous solution The nanofibers produced by forcespinning were characterized by SEM, FT-IR and TGA and the extraction of cobalt was evaluated by variation of the pH, solid:liquid (S:L) ratio, extraction time and Cyanex 272 content in the nanofibers. The best extraction efficiency was 99.96%, achieved under the following conditions: pH 8; (S:L) ratio of 1:200; 25% of Cyanex 272; Extraction time of 60 min. The maximum extraction capacity obtained was 15.46 mg Co/g of nanofiber and 70.15 mg Co/g of extractor. In successive reuse cycles, the results demonstrated that the extraction efficiency was maintained at over 85%. The findings showed that Nylon 6/Cyanex 272 nanofibers are a new robust and promising material for the recovery of heavy metals from aqueous solution, confirming that nanofibers have an efficiency similar to conventional liquid–liquid extraction, without the disadvantage of volatile organic compounds emissions generated by the use of organic diluents.