Polypyrrole-Barium Ferrite Magnetic Cryogels for Water Purification

Abstract

Magnetic polypyrrole-gelatin-barium ferrite (PPy-G-BaFe) cryogels/aerogels were synthesized by one-step oxidative cryopolymerization of pyrrole in the presence of various fractions of barium ferrite (BaFe) nanoparticles, dispersed in aqueous gelatin solution. The successful incorporation of BaFe into the composites was confirmed by elemental analysis and scanning electron microscopy paired with an energy-dispersive X-ray detector. The maximum achieved content of BaFe in the resulting material was 3.9 wt%. The aerogels with incorporated BaFe had significantly higher specific surface area and conductivity, reaching 19.3 m2 g−1 and 4 × 10−4 S cm−1, respectively, compared to PPy-G aerogel, prepared in the absence of BaFe (7.3 m2 g−1 and 1 × 10−5 S cm−1). The model adsorption experiment using an anionic dye, Reactive Black 5, showed that magnetic PPy-G-BaFe aerogel, prepared at 10 wt% BaFe fraction, had significantly higher adsorption rate and higher adsorption capacity, compared to PPy-G (dye removal fraction 99.6% and 89.1%, respectively, after 23 h). Therefore, the prepared PPy-G-BaFe aerogels are attractive adsorbents for water purification due to their enhanced adsorption performance and the possibility of facilitated separation from solution by a magnetic field.

Magnetic Polypyrrole-Gelatin-Barium Ferrite Cryogel as an Adsorbent for Chromium (VI) Removal

“…PPy-G-BaFe and PPy-G aerogels were prepared by oxidative cryopolymerization of pyrrole in the presence or in the absence of BaFe magnetic particles, respectively. The detailed characterization of the aerogels, including their morphology, composition, mechanical characteristics, conductivity, etc., has been previously reported [36]. The present work was focused on the applicability of the aerogels as adsorbents for removal of Cr(VI) from the aqueous medium.…”

“…Figure 2 shows that PPy-G and PPy-G-BaFe aerogels had similar adsorption performance, which was not affected by the presence of BaFe magnetic particles. It is presumably attributed to its relatively low content (3.9 wt% [36]) in the aerogels). Thus, all further experiments were carried out using PPy-G-BaFe aerogels.…”

“…These materials can be prepared by oxidative one-step cryopolymerization in the presence of a water-soluble polymer, including gelatin [32,34], nanofibrillated cellulose [33], poly(vinyl alcohol) [35], methylcellulose [35], hydroxypropylcellulose [35] or poly(N-vinylpyrrolidone) [35], which acts as a stabilizer for improving mechanical properties. The macroporous structure and developed surface of PPy-based cryogels facilitate their application for water purification, which has been reported for adsorption of dyes [36], antibiotics [37,38] or Cr(VI) [33,35].…”

“…For this purpose, magnetic PPy-gelatin-barium ferrite (PPy-G-BaFe) cryogels were used in this work. The preparation of the cryogels by one-step oxidative cryopolymerization procedure, their characterization and application for the adsorption of dyes, such as Reactive Black 5, have been reported before [36]. They are the promising candidates for the water purification task due to the presence of magnetic BaFe particles, which enable their separation from the treated solution by magnetic field.…”

Self-Assembling Peptide-Based Magnetogels for the Removal of Heavy Metals from Water

“…To enhance hydrogels adsorption efficiency and reduce their operational costs, they can be hybridized (or combined) with magnetic nanoparticles (NPs) to form “magnetogels”, which are promising organic-inorganic nanohybrids for environmental and biological applications, as they combine benefits of both hydrogels and magnetic nanoparticles into a single inorganic/organic hybrid [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. In fact, magnetic sorbents entrapped within hydrogel-based materials can promote heavy metals removal thanks to the large number of functional groups on hydrogel surfaces, thus improving adsorption selectivity as well as sorbent capacity.…”