The influence of acid modification on the structure of montmorillonites and surface properties of bentonites

Krupskaya, V. V.; Novikova, L. A.; Tyupina, E. A.; Белоусов, П. Е.; Dorzhieva, O. V.; Закусин, С. В.; Kim, K. B.; Roessner, F.; Badetti, Elena; Brunelli, Andrea; Belchinskaya, Larisa

doi:10.1016/j.clay.2019.02.001

Cited by 64 publications

(34 citation statements)

References 37 publications

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“…As a result of numerous isomorphic substitutions in the mineral structural sheets, its particles had negative charges at the basal surfaces and positive charges at the edges, which provides conditions for a specific particle interaction like edge-to-face, edge-to-edge and face-to-face [ 59 ]. Therefore, the interaction between clay particles and polymer molecules is based on the charge attraction [ 60 ]. The adsorption of polymer chains was accompanied by its intercalation into the mineral structure in the form of a monolayer, causing an increase in the interlayer space, which is schematically presented in Figure 13 .…”

Section: Resultsmentioning

confidence: 99%

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

et al. 2021

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The article aims to verify the possibility of obtaining an organic–inorganic material acting as both a binder and a lustrous carbon carrier in bentonite-bonded molding sands. Due to the wide industrial application, organoclays can be considered as innovative materials supporting the foundry technology in meeting environmental requirements. In this study, the organic modification of montmorillonite in calcium bentonite (SN) was performed by poly(acrylic acid) (PAA) and its sodium salt (PAA/Na). Additionally, for the purpose of comparison, the sodium-activated bentonite/poly(acrylic acid) (SN-Na/PAA) composites were also prepared. The collective analysis of the research results used in the assessment of the mineral/polymer interaction mechanism indicates surface adsorption combined with the intercalation of PAA monolayer into the mineral interlayer spaces. Materials were characterized by the combination of Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods. Based on the XRD analysis, the influence of PAA/Na on the aluminosilicate layered structure was found to be destructive, which may adversely affect the binding properties of SN/PAA/Na composites considered as a potential group of new foundry binders. The SN/PAA and SN-Na/PPA composites (with appropriate polymer content) can act as a binding agent in the synthetic molding sand technology, despite coating the bentonite particles with polymer molecules. The risk of losing the mineral′s binding capacity is reduced by the good binding properties of pol(acrylic acid) itself. The article is the first stage (preceding the thermal analysis and the strength tests of molding sands with the prepared organobentonites) in determining the possibility of obtaining a new full-value foundry binder in molding sands with bentonite.

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Section: Resultsmentioning

confidence: 99%

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

et al. 2021

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“…The sample of Bentonite was chosen with a Na-form of montmorillonite. Exposure of acidic conditions at pH < 4 should lead to a partial exchange of interlayer Na + and the leaching of octahedral Al 3+ , Mg 2+ and Fe 2,3+ [41][42][43], which may further compete with Cs + . At the same time, diatomite has a sufficient content of smectite and defective kaolinite (possibly halloysite or mixed mineral of the kaolinite-smectite range), which can also supply interlayer and octahedral cations in a solution at low pH, which in turn can compete with Cs + .…”

Section: Cesium Sorptionmentioning

confidence: 99%

Cesium Sorption and Desorption on Glauconite, Bentonite, Zeolite, and Diatomite

et al. 2019

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This study is devoted to studying the sorption of 137Cs on mineral sorbents at a wide pH range, from 2 to 10, as well as to studying sorption mechanisms. In order to obtain the most reliable sorption characteristics, samples of high purity were examined as sorbents: bentonite, glauconite, zeolite, and diatomite. A detailed description of their mineral composition, cation exchange capacity and specific surface of sorbents is given. XRD, XRF, FTIR, SEM, and BET adsorption methods were used for assaying. The sorption and desorption values were identified for each sorbent. As a result of the conducted research, it can be concluded that 137Cs sorption mainly occurs through the exchange reaction on zeolite, glauconite and bentonite. The highest cesium Kd was observed on zeolite due to its high CEC and amounted to 4.05 mg/L at pH 7. The higher sorption capacity of glauconite in comparison with bentonite is primarily due to the high layer charge which is mainly localized in tetrahedral sheets, and to the existence of highly selective sorption sites (frayed edge sites) on the glauconite surface. Diatomite showed the lowest sorption capacity provided by the presence of a small quantity of smectite and kaolinite in its composition. The values of desorption increase in the following order: zeolite < bentonite ~ diatomite < glauconite.

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“…This reaction inform Al has changed to hydroxyl structure that give an impact of change of octahedral to tetrahedral. Changed of octahedral to tetrahedral made the crystal lattice is negatively charged, negative charged will neutralizing by alkali in bentonite (Krupskaya et al, 2019). Activated bentonite used ZnCl 2 and NaCl make an exchange of Zn and Na.…”

Section: Resultsmentioning

confidence: 99%

Activated Bentonite: Low Cost Adsorbent to Reduce Mercury Content in A Solution

Naswir¹,

Desfaurnatalia²,

Septiarini³

et al. 2019

Res. J. Applied Sci.

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The purpose of this study is to find the best activator for bentonite to reduce the mercury content in a solution. Bentonite was activated by HCl, H 3 PO 4 , NaCl, ZnCl 2 , NaOH and KOH use different concentration such as 0.5, 1.0 and 1.5M. Activated bentonite has been characterized by x-ray diffraction, scanning electron microscope with energy dispersive spectroscopy and atomic absorption spectrometry. Bentonite characterization showed that bentonite contains kaolinite, montmorillonite, quartz and cristobalite. Activated bentonite has bigger pores than natural bentonite. Atomic absorption spectrometry showed that H 3

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The influence of acid modification on the structure of montmorillonites and surface properties of bentonites

Cited by 64 publications

References 37 publications

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

Cesium Sorption and Desorption on Glauconite, Bentonite, Zeolite, and Diatomite

Activated Bentonite: Low Cost Adsorbent to Reduce Mercury Content in A Solution

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