Wan Ahmad Kamil Mahmood

Solid polymer electrolytes (SPEs) have been considerably investigated due to various electrochemical device applications. Most of the SPEs comprise polymer as a host material to provide strength and good mechanical stability and salt that transfers charge carriers to cause conductivity. Nanocomposite solid polymer electrolyte membranes based on poly(vinyl alcohol) (PVA)-poly(ethylene glycol) (PEG) blend complexed with LiClO4 and nanofillers Al2O3 at different weight percent ratios have been obtained by using electrospinning method. The conductivity and structural properties of the different systems have been characterized by using various experimental approaches such as X-ray diffraction (XRD) and Fourier transform infrared FTIR spectroscopy. The ionic conductivity of the systems has been measured by using an LCR meter in a temperature ranging from 298 to 353 K. Maximum ionic conductivity of 1.58 × 10-4 S cm-1 at room temperature has been observed for the system of PVA-PEG-LiClO4-Al2O3 (50-25-15-10) with 15 wt% weight percent of LiClO4 salt in PVA-PEG blend matrix. The ac conductivity report indicates that the ionic conductivity of the PVA-PEG-LiClO4-Al2O3 complex is influenced by the concentration of LiClO4. The effect of temperature on the ionic conductivity of polymer electrolyte complexes has been estimated by changing the temperature ranging from 298 to 353 K. However, the conductivity of the nanofiber polymer electrolyte systems increases with the rise of temperature, and the maximum conductivity of 1.58 × 10-2 S cm-1 has been recorded at 353 K. The temperature-dependent conductivity follows the Arrhenius behavior.

The conductive and stretchable films with improved hardness are suitable for the fabrication of flexible electronic devices. This study describes the sol–gel technique to prepare a novel conductive and flexible film consisting of epoxidized natural rubber (ENR), doped polyaniline (PD) and zirconia. The zirconia networks were directly synthesized in‐situ in ENR/PD solution and flexible conductive composite film with improved hardness was obtained. The morphology study revealed the size of PD decreased significantly from 77.89 ± 43.95 nm to 4.32 ± 1.13 nm and highest electrical conductivity of 1.9 × 10⁻³ S/cm was achieved with 10 wt.% percolation threshold of zirconia precursor. The binding energy of Zr3d_5/2 and Zr3d_3/2 decreased, suggesting that zirconia was converted to the lower oxidation state. Furthermore, the shape of PD changed from spherical to rod‐like structure with root mean square value of 2 nm, while the hardness and reduced modulus improved to 1.72 MPa and 36.7 MPa, respectively.

This study describes the preparation and characterization of nanofibers with poly(vinyl alcohol) (PVA) as the wall matrix to encapsulate montmorillonite (MMT) clay and intercalated MMT‐urea nanocomposite using an electrospinning technique. Nanofibers encapsulated with (1–5%, w/w) MMT clay were successfully produced and characterized in relation to morphological, spectroscopic, structural, surface, and thermal properties. The electrospinning conditions for voltage, flow‐rate, and emitter to collector distance were 20 kV, 0.5, and 0.25 mL/h, and 10 cm, respectively. The surface roughness increased from 43.5 (empty fibers) to 56 nm in the PVA/MMT‐3% and bead‐less nanofibers were formed with the maximum diameter distribution and mean diameter value of 45–80 and 62 nm, respectively. The d‐spacing was increased significantly from 1.004 in MMT to 1.684 nm in MMT‐urea, indicating the intercalation of urea occurred successfully. Furthermore, elemental analysis results showed that the intercalated MMT‐urea contained 30.4% nitrogen. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45957.

The present study describes the preparation and characterization of a novel nanocomposite, based on montmorillonite clay (MMT) encapsulation in poly(ethylene glycol) (PEG) by an electrospraying process. PEG/MMT nanocomposites with MMT contents ranging from 1 to 5 wt % were successfully prepared and characterized in relation to their morphological, spectroscopic, structural, and thermal properties. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy micrographs showed that the PEG nanobeads formed spherical shapes, and with increasing amount of MMT clay, the size of the beads decreased significantly, ranging from 120 to 3.7 nm. The Fourier transform infrared spectroscopy results suggested that there was no significant chemical interaction between PEG and MMT clay. However, the d‐spacing of MMT clay in PEG/MMT increased, a clear indication of the intercalation of PEG in the interlayer spaces of MMT clay. Furthermore, the thermal stability of PEG polymer decreased upon encapsulation of MMT clay in PEG/MMT composites. Nanoindentation results showed that the hardness and Young's modulus of the PEG/MMT composites increased with 3 wt % loading of MMT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45048.

Summary: This study describes the preparation and characterisation of nanoparticles with gelatin as the wall matrix to encapsulate Moringa oleifera (MO) extract using an electrospraying technique. The electrospraying conditions for voltage, flow rate and emitter/collector distance were 20 kV, 0.5 mL h⁻¹ and 10 cm, respectively. Nanoparticles with encapsulated MO extract (1–5%, w/w) were successfully produced and characterised in relation to spectroscopic, morphological and thermal properties. Increasing amounts of MO extract resulted in a significant decrease in the nanocapsule size (ranging from 140 and 179 nm) produced. Spectroscopic analysis indicated no chemical interactions between core and wall materials. The encapsulation efficiency (EE) of MO extract‐loaded nanocapsules obtained was 83.0 ± 4.0%. Surface analysis showed that roughness decreased from 91 nm (empty beads) to 57.5 nm with addition of 3% MO extract. The thermal stability of encapsulated nanoparticles slightly increased and the glass transition temperature (T_g) disappeared due to increase in crystallinity.