Electroactive behavior assessment of poly(acrylic acid)‐graphene oxide composite hydrogel in the detection of cadmium

Abstract

Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous solutions were studied and revealed that the GO enables greater mechanical stability in the materials. The PAA hydrogels, with the same degrees of neutralization, were also prepared without GO to compare with the composites. Additionally, carbon paste electrodes (CPE) modified with the composites PAA-GO were used to asses and compare their adsorption properties with cadmium(II). The anodic stripping voltammetry (ASV) peak, in the differential pulse voltammetry mode, for cadmium oxidation was found to be influenced by the presence of GO into the polymer, and also by their percentage of neutralization. The accumulation of cadmium(II) on the surface of the modified CPEs was performed under opencircuit conditions taking an account the preconcentration time of the metal cation. The presence of GO enhances the electrical signal of the electrodes in short times of immersion in cadmium(II) solutions. This property contributed to get linear responses of the CPEs modified with the composites, which were influenced by their degrees of neutralization. The PAA-GO 10N electrode with 10% of neutralization combined the influence of GO and the degree of neutralization in the same matrix, and also showed good performance in terms of its mechanical stability, it was chosen for preliminary studies on the selectivity of the electrode toward Zn(II) and Cu(II).

Surface modification and immobilization in poly(acrylic acid) of Ag/ZnO for photocatalytic degradation of endocrine‐disrupting compounds

“…In addition, a new intense peak at 1540 cm −1 was assigned to the ionized carboxylate groups (COO − ). The ionization of carboxylate groups in partially neutralized PAA has also been reported, where the H + ions of carboxylic groups in the backbone chains are irreversibly replaced by Na + . In the present study, the cationic ions are provided by ZnO‐Zn 2+ in the acidic medium during the polymerization, resulting in conditions of partial neutralization.…”

Synthesis of Bamboo-like Multiwall Carbon Nanotube–Poly(Acrylic Acid-co-Itaconic Acid)/NaOH Composite Hydrogel and its Potential Application for Electrochemical Detection of Cadmium(II)

“…The CPEs were prepared according to the methodology used by Bejarano-Jimenez et al [ 32 ]. The dried PAA-co-IA/NaOH and PAA-co-IA/NaOH/B-MWCNT polymers were crushed to pass through a <150 mm sieve.…”

“…The absorption of Cu(II), Zn(II), Ni(II), Co(II), Cd(II), Pb(II), and Hg(II) ions was evaluated with PAA-co-IA hydrogels, where it was determined that the degree of swelling was proportional to the content of itaconic acid [ 31 ]. In a previous work of the group, it was demonstrated that NaOH hydrogel neutralizing was a key factor in swelling as well as in its ability to remove rust in metallic surfaces [ 32 ]. In this effort, a novel synthesis of PAA-co-IA/NaOH/B-MWCNT hydrogel was developed for potential use as an electrode modifier of Cd(II) sensing carbon paste electrodes.…”

Recent Progress of Graphene‐Containing Polymer Hydrogels: Preparations, Properties, and Applications

“…By addition of chemical cross‐linker, the mechanical properties can be increased obviously. There are many reports to demonstrate polymer–graphene hydrogels such as PAM–GO hydrogel, PAA–GO, and PNIPAM–GO hydrogel by using chemical cross‐linkers.…”