This research paper
describes the fabrication of bionanocomposites
(BNCs) based on silk fibroin (SF) and reduced graphene oxide (rGO).
The recorded UV–visible (UV–vis) spectra of the sample
confirm the reduction of GO to rGO in SF by showing a plasmon resonance
band within the wavelength range of 261–268 nm. The X-ray diffraction
(XRD) peak at 11.6° corresponding to the GO intensity decreases
with increasing reaction time, resulting in rGO in the SF host matrix.
The morphological behavior of the SF–rGO BNCs is scrutinized
using scanning electron microscopy (SEM), and the images clearly indicate
the existence of rGO within the matrix. The increasing amount of GO
in the SF shows broken graphene sheets, which can increase the surface
roughness and establish a strong physical contact between the SF and
rGO nanosheets. The high-resolution transmission electron microscope
(HR-TEM) image of the bionanocomposite showed that the formed rGO
encompassments of fewer layers are stacked, each with fewer wrinkles
and folding. The Raman spectroscopy confirmed the formation of rGO
by showing the increased intensity ratio of D to G band (I
D/I
G) in the bionanocomposite
samples. The rGO effect on the electrical conductivity is measured,
and the results show that DC conductivity increases from 1.28 ×
10–9 to 82.4 × 10–9 S/cm
with an increase in the GO content in the SF biopolymer. The investigations
demonstrate loss of the insulation property and improved conducting
behavior of the SF biopolymer.