Preparation of poly(γ-benzyl-L-glutamate) nanofibers by electrospinning from isotropic and biphasic liquid crystal solutions

Liquid crystal polymer (LCP) nanofibers were prepared by electrospinning from isotropic and biphasic poly(gamma-benzyl-L-glutamate) (PBLG)/dichloromethane-pyridine solutions. The prepared fibers were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, polarized optical microscopy, wide-angle X-ray diffraction and polarized micro-Raman spectroscopy. The as-spun PBLG fiber from the isotropic solutions had an undulating orientation of closed-packed alpha-helices similar to a serpentine trajectory in their internal structures. The as-spun PBLG fibers from the biphasic solutions that contained the LC phase had uniaxially oriented hexagonal lattices of alpha-helices along the fiber axis. These results indicated that the orientation of the ordered structure of the electrospun lyotropic LCP fibers can be controlled by the initial microstructure of the spinning solution. Polymer Journal (2012) 44, 360-365; doi:10.1038/pj.2011.137; published online 11 January 2012