Acid‐treated Bentonite as filler in the development of novel composite PVA hydrogels

Abstract

In this study, novel eco‐friendly hydrogel adsorbents were synthesized based on poly(vinyl alcohol) (PVA) and different contents of an acid‐treated bentonite (1–5 wt %). The hydrogels were prepared by freezing–thawing, which is a simple and nontoxic method. The materials were morphologically and thermally characterized by means of swelling assays, X‐ray diffraction, scanning electron microscopy, dynamic scanning calorimetry, and thermogravimetric analysis in order to evaluate the effect of acid‐treated bentonite loading. The composite hydrogels showed very distinct porous structure and thermal features in comparison to neat PVA as a consequence of the addition of the clay. Moreover, the performance of the obtained composite hydrogels was tested toward the adsorption of cationic (methylene blue) and anionic dyes (methyl red and methyl orange) from aqueous media. The presence of acid bentonite seems to be beneficial for improving the removal capacity of PVA‐based hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47663.

Tillandsia Aeranthos flower‐like magnetic nanostructures confined into polyvinyl alcohol beads

“…As Zhou and collaborators have previously reported for similar magnetic systems, the cross‐linking dots are produced as a result of the strong hydrogen bonding interactions between the MNPs and the –OH groups from the PVA 87 . This kind of entanglement involving hydrogen bonding interactions between the PVA matrix and the included filler to form the desired composite material is a well‐known fact 32 …”

“…87 This kind of entanglement involving hydrogen bonding interactions between the PVA matrix and the included filler to form the desired composite material is a well-known fact. 32 In accordance to the obtained results it was decided to continue the research only considering four of the developed materials: the hydrated and the dried, high-FeOx beads. The magnetization studies revealed that there is no significant difference between the saturation magnetization (Ms) of the C0 and C3 samples ( Figure 11).…”

“…Since the need for their removal from polluted water is widely recognized, a variety of methodologies and treatments has been researched 26–29 . Among them, water remediation through adsorption processes is considered a promising alternative from costs, operational complexity, and reusability points of view 30–34 . Adsorbents should be as green as possible and at the same time, they should be able to perform an efficient treatment toward the removal of a target compound.…”

“…[26][27][28][29] Among them, water remediation through adsorption processes is considered a promising alternative from costs, operational complexity, and reusability points of view. [30][31][32][33][34] Adsorbents should be as green as possible and at the same time, they should be able to perform an efficient treatment toward the removal of a target compound. Several nanoscale materials have been successfully used as adsorbents toward a variety of synthetic chemicals removal.…”

Tensile Fatigue of Poly(Vinyl Alcohol) Hydrogels with Bio‐Friendly Toughening Agents

“… where ΔH was calculated as the area under the melting peak, is the heat needed to melt a 100% crystalline PVA (138.6 J g −1 ), and W PVA is weight fraction of the PVA polymer in the hydrogel sample with respect to deionized water. [ 50,89,90 ] Figure 7b provides a view of the trend of crystallinity degree with increasing starch.…”