Fig. 2

Morphological and structural characterizations. a Micro-Raman spectra of PE powder, PEMF and PENF where the data is normalized to the highest peak of each spectrum. b Ratio of integral areas of Raman band 1414 cm⁻¹ to Raman bands 1293 cm⁻¹ and 1305 cm⁻¹ vs. intensity ratio of Raman bands 1128 cm⁻¹ to 1060 cm⁻¹. c TEM micrograph of a PENF. d SAED pattern of the PENF in c Inset shows the distinct diffraction spots of (200) plane of parent crystal (subscript P) and (110) plane of twinned crystal (subscript T). Arrow indicates the drawing direction. e Orthorhombic crystal structure of PE. Scale bar, 500 nm