Fluorescence and structural properties of polyvinyl alcohol fibers modified with multiwalled carbon nanotubes-hyperbranched poly (phenylalanine-lysine)

In order to significantly enhance the fluorescence and mechanical properties of polyvinyl alcohol (PVA) fluorescent fibers, HBP(P-L) is synthesized by lysine, phenylalanine and N,N-methylene bisacrylamide via Michael addition reaction. Acidified multiwalled carbon nanotubes (MWCNTs) are added in HBP(P-L) solution, which are sonicated to obtain MWCNTs-HBP(P-L). Moreover, MWCNTs-HBP(P-L) is incorporated with PVA polymer to fabricate PVA fluorescence fibers via wet spinning. The fluorescence and mechanical properties of fabricated PVA fluorescence fibers are characterized by SEM, FTIR, XRD, DSC, fibers tensile tester and fluorescence spectroscopy. The results display that the neat PVA fibers could not emit fluorescence when emission peak is at 450-480 nm, while MWCNTs-HBP(P-L)/PVA fibers could emit green fluorescence. The neat PVA fibers still could not emit fluorescence when emission peak is at 530-550 nm, while MWCNTs-HBP(P-L)/PVA fibers could emit dark red fluorescence. Furthermore, the crystallinity, the degree of orientation, the breaking strength and modulus of MWCNTs-HBP(P-L)/PVA fibers are 65.0%, 93.8%, 6.52 cN/dtex and 76.33 cN/dtex, respectively. Especially, the breaking strength and modulus of MWCNTs-HBP(P-L)/PVA fibers are 15.2% and 82.1% higher than that of neat PVA fibers. The fabricated MWCNTs-HBP(P-L)/PVA fibers exhibit unique mechanical and fluorescence properties, which make it be potentially envisaged in biomedical application.