Novel Covalently Cross-Linked Attapulgite/Poly(acrylic acid-co-acrylamide) Hybrid Hydrogels by Inverse Suspension Polymerization: Synthesis Optimization and Evaluation as Adsorbents for Toxic Heavy Metals

Abstract

Novel covalently cross-linked microbeads of attapulgite/poly(acrylic acid-co-acrylamide) [ATP/P(AA−AM)] hybrid hydrogels with excellent mechanical stability were synthesized by the inverse suspension copolymerization of acrylic acid (AA) and acrylamide (AM) with multifunctional attapulgite nanorods (MF-ATP) as the sole cross-linker. The synthesis conditions, such as feeding method, neutralization degree of AA, and feed ratio of the comonomers to MF-ATP, were optimized scientifically. The TGA results showed that 96% of the comonomers (AA and AM) were grafted onto the MF-ATP nanorods to form a three-dimensional network skeleton of the hybrid hydrogels, for a feed ratio of MF-ATP nanorods to comonomers of 1:5. The ATP/P(AA−AM) hybrid hydrogels exhibited selective adsorption toward toxic heavy-metal ions, especially Pb 2+ and Cu 2+ ions. In addition, the adsorbed ions could be easily desorbed, indicating the reusability of the ATP/P(AA−AM) hybrid hydrogels. Their use as an adsorbent for toxic heavy-metal ions can therefore be expected to be economically and technically feasible.

Recent progress in gelatin hydrogel nanocomposites for water purification and beyond

“…Figure 9and in the fifth circle, the regeneration efficiency was reported to be 87.1 % and 93.6 % for gelatin grafted poly(acrylic acid) (GE-g-PAA/APT-0) and gelatin grafted poly(acrylic acid)/attapulgite (GE-g-PAA/APT-5, 5 is percentage of APT) respectively. This better adsorption efficiency was related to the cross linker behavior of attapulgite in polymerization process [59,60]. SEM study of the synthesized hydrogels was also carried out to study their porous surface (Fig.…”

Effects of feed palygorskite inclusion on pelleting technological characteristics, growth performance and tissue trace elements content of blunt snout bream (Megalobrama amblycephala)

“…Clay minerals are widely used for the removal of heavy metal ions (Bradl, 2004;Liu et al, 2014). Potgieter et al (2006) found that the metal ions (Pb and Cr) from aqueous solution can be adsorbed successfully in significant amounts by palygorskite.…”

Preparation of Fe3O4/attapulgite/polyvinylalcohol composites and its treatment for methyl orange in neutral condition

“…First, as PVA is introduced, the hydroxyl of PVA can modify the attapulgite, which can improve the ability of adsorption of attapulgite. There are many similar experiments that attapulgite is modified with the organics for improving the adsorption . Second, after introducing the PVA, PVA bonds with iron atoms, which contributes to the fabrication of dispersed Fe 3 O 4 particles .…”