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Polymeric microparticles have been shown to have great impacts in the area of drug delivery, biosensing, and tissue engineering. Electrospray technology, which provides a simple yet effective technique in the creation of microparticles, was utilized in this work. In addition, altering the electrospray experimental parameters such as applied voltage, flow rate, collector distance, solvents, and the polymer-solvent mixtures can result in differences in the size and morphology of the produced microparticles. The effects of the flow rate at (0.15, 0.3, 0.45, 0.6, 0.8, and 1 mL/h) and N, N-Dimethylformamide (DMF)/acetone solvent ratios (20:80, 40:60, 60:40, 80:20, 100:0 v/v) in the production of polyvinylidene fluoride (PVDF) microparticles were studied. Scanning electron microscopy (SEM) was used to observe changes in the morphology of the microparticles, and this revealed that a higher acetone to DMF ratio produces deformed particles, while flow rates at (0.3 and 0.45 mL/h) and a more optimized DMF to acetone solvent ratio (60:40 v/v) produced uniform spherical particles. We discovered from the Raman spectroscopy results that the electrosprayed PVDF microparticles had an increase in piezoelectric β phase compared to the PVDF pellet used in making the microparticles, which in its original form is α phase dominant and non-piezoelectric.

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In this work, we report on the synthesis and performance evaluation of electrosprayed multi-walled carbon nanotubes (MWCNTs)/ Polyvinylidene Fluoride (PVDF) nanocomposite materials for gas detection of volatile organic compounds. MWCNTs are characterized by a hollow structure, large surface area and several unique properties that make them potentially excellent for gas sensing. However, in order to improve their sensitivity, stability and reproducibility effects, the carbon nanotubes were doped with PVDF polymer in a minimal concentration such that it utilizes its strong binding effect with interconnected nanotubes and the substrate and further, the polymer does not affect the dominance of MWCNTs on the surface as observed from SEM characterization. The electrospray deposition technique, combined with sonication, was used to ensure the MWCNT was dispersed evenly in the polymer matrix, as MWCNTs tend to aggregate due to their strong Van der Waals forces. The sensing mechanism and the kinetic adsorption of gases on the sensors were studied and the experimental result shows that MWCNT-OH/PVDF sensor revealed a larger sensitivity than that of MWCNT-OH sensor to tested VOCs at room temperature.