Highly Efficient Copper(II) Ion Sorbents Obtained by Calcium Carbonate Mineralization on Functionalized Cross‐Linked Copolymers

Abstract

A new type of Cu(II) ion sorbents is presented. These are obtained by CaCO3 mineralization from supersaturated solutions on gel-like cross-linked polymeric beads as insoluble templates. A divinylbenzene-ethylacrylate-acrylonitrile cross-linked copolymer functionalized with weakly acidic, basic, or amphoteric functional groups has been used, as well as different initial inorganic concentrations and addition procedures for CaCO3 crystal growth. The morphology of the new composites was investigated by SEM and compared to that of the unmodified beads, and the polymorph content was established by X-ray diffraction. The beads, before and after CaCO3 mineralization, were tested as sorbents for Cu(II) ions. The newly formed patterns on the bead surface after Cu(II) sorption were observed by SEM, and the elemental distribution on the composites and the chemical structure of crystals after interaction with Cu(II) were investigated by EDAX elemental mapping and by FTIR-ATR spectroscopy, respectively. The sorption capacity increased significantly after CaCO3 crystals growth on the weak anionic bead surface (up to 1041.5 mg Cu(II) /g sample) compared to that of unmodified beads (491.5 mg Cu(II) /g sample).

Superparamagnetic Composites Based on Ionic Resin Beads/CaCO3/Magnetite

“…As shown in our previouss tudy, [16] CaCO 3 mineralization using ion-exchanger beads takes place irrespective of the natureo ft he functional groups on the beads or of the reactants addition order.T he presence of magnetite in the reaction system is expected to furtheri nfluence the CaCO 3 mineralization pathway due to the carboxylate ions corona. Actually, ionic beads were expected to act as organic templates, inducing the mineralization,w hereas the surfactated magnetite was expected to control the growth of the specific polymorphs or guide the assembly of the crystals nanoparticles.…”

“…Figures 1a nd 2s how that, beside the nature of the ionic groups on ion-exchanger beads, the addition order of the reactants has an im- Chem.E ur.J. [16] At working pH (pH 8), the acidic groups of AIE are completely ionized and only as mall part of the secondary amine groups are in protonated form;t herefore, the main functional group that controls crystal nucleation is ÀCOO À .T herefore, when MF was first added on AIE beads (Figures 2a and b), the anionic groups on the beads surfaced on ot interact electrostatically with the carboxylic groups on the oleic acid coronao nm agnetite and, therefore, alower magnetite amount is expected to be found in the beads. When Ca or CO 3 were first added (Figure 1c and d), the already formed crystallization seeds seems to not be influencedb yt he further addition of MF,t he CIE beads (Ca/MF/CO 3 and CO 3 /MF/Ca) being covered by at hin layer of CaCO 3 crystals, similar to that obtained in the absence of MF and the same inorganic precursors concentration.…”

“…[16,19] The EDX method allows the quantitative determination of the atomicp ercento ft he elements in the investigated samples. [16] The amount of magnetite included in the composites dependso nt he nature of the ionic groups on the beads surface and on the inorganic precursor addition protocol. Calcium can be considered as al abel for the CaCO 3 inorganic phase, andt herefore changes in its relative content can be explained by its distribution in the organic phase.…”

A rapid and visual turn-off sensor for detecting copper (II) ion based on DNAzyme coupled with HCR-based HRP concatemers

“…Of particular interest there has been the detection of copper (II) ion, a dangerous pollutant that causes adverse afflictions in people upon excess intake, including liver or kidney damage, gastrointestinal disturbance5, Parkinson’s disease, Wilson’s disease and Alzheimer’s disease34. Considering its toxicity, the Chinese Ministry of Health (CMH), U.S.…”

Hemin/G-quadruplex-based DNAzyme concatamers for in situ amplified impedimetric sensing of copper(II) ion coupling with DNAzyme-catalyzed precipitation strategy

“…Copper (Cu 2 þ ) ion is an essential micronutrient element as a cofactor and/or structural component to support the biological metabolic activities of numerous enzymes and proteins (Verwilst et al, 2015;Hosseini et al, 2015). Unfavorably, excess copper intake to human body may cause some adverse afflictions, e.g., liver or kidney damage, gastrointestinal disturbance, and degrading memory in the elderly or individuals with Wilson's disease (Mihai et al, 2015). Recently, different methods and strategies based on various signal-generation principles have been developed for the determination of copper ion, e.g., by using atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), fluorescence spectroscopy, and voltammetric or colorimetric assay (Cao et al, 2015;Foroushani et al, 2015;Ndokoye et al, 2014;Park et al, 2014;Jin and Han, 2014;Ding et al, 2014).…”