Unveiling the effect of surface modification of spherical PVDF nanoparticles via ZIF-8 and NH2 functional groups on gas adsorption and cell nanotoxicity.

This study presents a facile, robust, and sustainable approach to enable spherical PVDF nanoparticles to serve as a multifunctional, versatile application platform. We focused on enhancing the PVDF nanoparticle performance by uniformly decorating the surface with zeolite imidazole framework nanoparticles (ZIF-8) and modification with -NH2 functional groups. The synthesis methods, results of material characterization techniques (SEM-EDS, FTIR, BET, XRD), and testing methods (gas sorption, confocal and holotomographic microscopy) are discussed to support the proposed concept. The decoration of PVDF nanoparticles resulted in non-selectively increased sorption capacity by a factor of 10 compared to the pristine PVDF particles for the CO2/N2 gas pair. In contrast, surface amination selectively increases CO2 sorption threefold compared to pristine PVDF, while the N2 sorption decreased. Higher CO2 sorption of modified samples agreed with BET analysis, which revealed increased sorption capacity after both modifications (PVDF-ZIF-8386.52 m2/g, PVDF-NH2 217. 86 m2/g and PVDF 87.14 m2/g). The nanotoxicity testing revealed intracellular uptake and moderate nanotoxicity of both PVDF (average particle size 0.3 μm, IC50 of 0.56 ± 0.02 mg/mL) and PVDF-ZIF-8 (size 1.1 μm, IC50 of 0.44 ± 0.01 mg/mL) particles in macrophages RAW 264.7, while not in other cell lines (MRC-5, and HeLa). Nevertheless, the toxicity was observed only at extreme concentrations (approx. > 0.5 mg/mL) absent in the environment, thus mitigating the risk of potential contamination of the environment by PVDF-ZIF-8 nanoparticles with adverse effects on living organisms and human health. Obtained results demonstrate the potential for tailoring PVDF nanoparticles to enhance their performance and ensure their safety, thereby opening promising avenues for their application in gaseous and aqueous media.