S 4800 sem microscope

Photoluminescence spectra were measured via using OmniFluo fluorescence spectrometer (Zolix, Beijing, China). Ultraviolet-visible (UV-vis) absorption spectra were taken on a UV-3600 Plus spectrophotometer (SHIMADZU CO., Ltd., Hong Kong, China). X-ray diffraction (XRD) measurements were measured on a Bruker/D8 FOCUS X-ray diffractometer (Billerica, MA, USA) with a Cu Kα radiation source (wavelength at 1.5405 Å). Transmission electron microscope (TEM) and high-resolution TEM (HRTEM) images were recorded with a Technai F20 transmission electron microscope (FEI, Hillsboro, OR, USA). Scanning electron microscopy (SEM) images were taken on a S-4800 SEM microscope (Hitachi, Ltd., Tokyo, Japan).

An S-4800 SEM microscope from Hitachi (Tokyo, Japan) was further used to observe the morphology of the electrospun PHB films, and their cross-sections and surfaces. Cross-sections of the samples were prepared by cryo-fracture of the electrospun PHB films in liquid nitrogen. Then, they were fixed to beveled holders by using conductive double-sided adhesive tape, sputtered with a mixture of gold-palladium under a vacuum, and observed using an accelerating voltage of 5 kV.

Flies were sputter coated with gold in a Pelco model 3 sputter coater 91000. Images were taken on a Hitachi S-4800 SEM microscope.