scholarly journals Adsorption of Pharmaceuticals onto Smectite Clay Minerals: A Combined Experimental and Theoretical Study

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Gwenaëlle Corbin ◽  
Emmanuelle Vulliet ◽  
Bruno Lanson ◽  
Albert Rimola ◽  
Pierre Mignon
Keyword(s):  
Interlayer Space ◽  
Theoretical Study ◽  
Van Der Waals Interactions ◽  
X Ray Diffraction ◽  
Basal Surface ◽  
Smectite Clay ◽  
X Ray ◽  
Clay Surface ◽  
Cation Coordination ◽  
Dynamics Simulations

The adsorption of two pharmaceuticals, carbamazepine and paracetamol, onto the expandable clay mineral saponite has been studied through the combination of kinetic experiments, X-ray diffraction, and theoretical modeling. Kinetic experiments indicate low adsorption for carbamazepine and paracetamol on expandable smectite clay. Accordingly, X-ray diffraction experiments show that neither compound enters smectite interlayer space. Molecular dynamics simulations were carried out to understand the interactions between the two pharmaceuticals and the saponite basal surface in the presence of Na+ cations. Calculations reveal that paracetamol almost does not coordinate solution cations, whereas a rather low coordination to cation is observed for carbamazepine. As a result, the adsorption onto the clay surface results mainly from van der Waals interactions for both pharmaceuticals. Carbamazepine does adsorb the surface via two configurations, one involving cation coordination, which corresponds to a rather stable adsorption compared to paracetamol. This is confirmed by structural analyses completed with desorption free energy profile.

Experimental and Theoretical Study on the Growth of Plate-like β-HMX Crystals in the Hydroxylated Interlayer Space

2021 ◽  
Author(s):  
Yuting Tao ◽  
Jinjiang Xu ◽  
Haobin Zhang ◽  
Shiliang Huang ◽  
Zuoyin Yang ◽  
...  
Keyword(s):  
Interlayer Space ◽  
Theoretical Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cooling Crystallization

Plate-like β-HMX crystals are grown in the hydroxylated interlayer space using a crystallization technique combining cooling crystallization and solvent-antisolvent method. The obtained crystals have been investigated by X-ray diffraction (XRD),...

Preparation of drug-montmorillonite UV-radiation protection compounds by gas-solid adsorption

Clay Minerals ◽  
2001 ◽  
Vol 36 (4) ◽  
pp. 541-546 ◽  
Author(s):  
C. del Hoyo ◽  
M. A. Vicente ◽  
V. Rives
Keyword(s):  
High Temperature ◽  
Ultraviolet Radiation ◽  
Interlayer Space ◽  
External Surface ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
X Ray ◽  
Clay Surface ◽  
Intercalation Complexes ◽  
Pure Drug

AbstractEthyl cinnamate/montmorillonite intercalation complexes were obtained by gaseous adsorption of the drug on the clay surface. They were characterized by powder X-ray diffraction, differential thermal and thermogravimetric analyses and by visible-UV and IR spectroscopies. It was found that after 1 day of adsorption, most of the drug enters the interlayer space of the clay by substitution of water molecules, and is removed only after heating at high temperature. In addition, a portion is physisorbed on the external surface of the crystallites, being removed easily below 100°C. The interlayer complex improves the protecting ability of the pure clay or the pure drug against ultraviolet radiation, specially in the so-called ‘C’ range (290–190 nm).

scholarly journals Diethylstilbestrol Modifies the Structure of Model Membranes and Is Localized Close to the First Carbons of the Fatty Acyl Chains

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 220
Author(s):  
Alessio Ausili ◽  
Inés Rodríguez-González ◽  
Alejandro Torrecillas ◽  
José A. Teruel ◽  
Juan C. Gómez-Fernández
Keyword(s):  
Membrane Surface ◽  
Water Layer ◽  
Fatty Acyl ◽  
31P Nmr Spectroscopy ◽  
Relaxation Rates ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Acyl Chains ◽  
Dynamics Simulations

The synthetic estrogen diethylstilbestrol (DES) is used to treat metastatic carcinomas and prostate cancer. We studied its interaction with membranes and its localization to understand its mechanism of action and side-effects. We used differential scanning calorimetry (DSC) showing that DES fluidized the membrane and has poor solubility in DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) in the fluid state. Using small-angle X-ray diffraction (SAXD), it was observed that DES increased the thickness of the water layer between phospholipid membranes, indicating effects on the membrane surface. DSC, X-ray diffraction, and 31P-NMR spectroscopy were used to study the effect of DES on the Lα-to-HII phase transition, and it was observed that negative curvature of the membrane is promoted by DES, and this effect may be significant to understand its action on membrane enzymes. Using the 1H-NOESY-NMR-MAS technique, cross-relaxation rates for different protons of DES with POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) protons were calculated, suggesting that the most likely location of DES in the membrane is with the main axis parallel to the surface and close to the first carbons of the fatty acyl chains of POPC. Molecular dynamics simulations were in close agreements with the experimental results regarding the location of DES in phospholipids bilayers.

Compressibility of β-As4S4: an in situ high-pressure single-crystal X-ray study

2012 ◽  
Vol 76 (4) ◽  
pp. 963-973 ◽  
Author(s):  
G. O. Lepore ◽  
T. Boffa Ballaran ◽  
F. Nestola ◽  
L. Bindi ◽  
D. Pasqual ◽  
...  
Keyword(s):  
Pressure Range ◽  
Substantial Reduction ◽  
Structural Data ◽  
Unit Cell ◽  
Van Der Waals Interactions ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Intermolecular Distances

AbstractAmbient temperature X-ray diffraction data were collected at different pressures from two crystals of β-As4S4, which were made by heating realgar under vacuum at 295ºC for 24 h. These data were used to calculate the unit-cell parameters at pressures up to 6.86 GPa. Above 2.86 GPa, it was only possible to make an approximate measurement of the unit-cell parameters. As expected for a crystal structure that contains molecular units held together by weak van der Waals interactions, β-As4S4 has an exceptionally high compressibility. The compressibility data were fitted to a third-order Birch–Murnaghan equation of state with a resulting volume V0 = 808.2(2) Å3, bulk modulus K0 = 10.9(2) GPa and K' = 8.9(3). These values are extremely close to those reported for the low-temperature polymorph of As4S4, realgar, which contains the same As4S4 cage-molecule. Structural analysis showed that the unit-cell contraction is due mainly to the reduction in intermolecular distances, which causes a substantial reduction in the unit-cell volume (∼21% at 6.86 GPa). The cage-like As4S4 molecules are only slightly affected. No phase transitions occur in the pressure range investigated.Micro-Raman spectra, collected across the entire pressure range, show that the peaks associated with As–As stretching have the greatest pressure dependence; the S–As–S bending frequency and the As–S stretching have a much weaker dependence or no variation at all as the pressure increases; this is in excellent agreement with the structural data.

Adsorption of the harmful hormone ethinyl estradiol inside hydrophobic cavities of CTA+ intercalated montmorillonite

2016 ◽  
Vol 74 (3) ◽  
pp. 663-671 ◽  
Author(s):  
A. E. Burgos ◽  
Tatiana A. Ribeiro-Santos ◽  
Rochel M. Lago
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
High Efficiency ◽  
Interlayer Space ◽  
Ethinyl Estradiol ◽  
Significant Loss ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrophobic Cavity ◽  
Adsorption Capacities ◽  
Derivative Thermogravimetry

Hydrophobic cavities produced by cetyltrimethylammonium cation (CTA+) exchanged and trapped in the interlayer space of montmorillonite were used to remove the harmful hormone contaminant ethinyl estradiol (EE2) from water. X-ray diffraction, thermogravimetry/derivative thermogravimetry, elemental analysis (carbon, hydrogen, nitrogen), Fourier transform infrared, scanning electron microscopy/energy dispersive spectroscopy, Brunauer–Emmett–Teller and contact angle analyses showed that the intercalation of 9, 16 and 34 wt% CTA+ in the montmorillonite resulted in the d001 expansion from 1.37 to 1.58, 2.09 and 2.18 nm, respectively. EE2 adsorption experiments showed that the original clay montmorillonite does not remove EE2 from water whereas the intercalated composites showed high efficiency with adsorption capacities of 4.3, 8.8 and 7.3 mg g−1 for M9CTA+, M16CTA+ and M34CTA+, respectively. Moreover, experiments with montmorillonite simply impregnated with cetyltrimethylammonium bromide showed that the intercalation of CTA+ to form the hydrophobic cavity is very important for the adsorption properties. Simple solvent extraction can be used to remove the adsorbed EE2 without significant loss of CTA+, which allows the recovery and reuse of the adsorbent for at least five times.

A Sulfide Ion Sensor from Commercial Bentonite

2014 ◽  
Vol 894 ◽  
pp. 412-415
Author(s):  
Duangsamorn Morawong ◽  
Atchana Wongchaisuwat ◽  
Ladda Meesuk
Keyword(s):  
Interlayer Space ◽  
Intercalation Compound ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
X Ray ◽  
Sulfide Ion ◽  
Best Response ◽  
Percent Recovery ◽  
Synonymous Term ◽  
Nernstian Slope

Bentonite is a synonymous term of montmorillonite which is a clay mineral consisting of 2 : 1 aluminosilicate layered structure. In this work, a commercial bentonite was used to prepare an intercalation compound [Ca (2,2-bipyridine)3]2+in the interlayer space, by solid-solid reaction, which formation was confirmed by the expansion of the interlayer space of bentonite from 1.5 to 1.8 nm, by powder X-Ray Diffraction technique. The intercalation compound [Ca (2,2-bipyridine)3]2+-bentonite was then used as a sensor to assemble a potentiometric electrode. The electrode gave best response to sulfide ion in terms of Nernstian slope. Precision of measurement, reproducibility and percent recovery were also studied. The electrode could be used to measure sulfide ion in real water samples and gave satisfactory results.

scholarly journals Intercalation of oxalate ions in the interlayer space of a layered double hydroxide for nickel ions adsorption

2016 ◽  
Vol 5 (2) ◽  
pp. 144
Author(s):  
Doungmo Giscard ◽  
Théophile Kamgaing ◽  
Ranil Clément Tonleu Temgoua ◽  
Ervice Ymele ◽  
Francis Merlin Melataguia Tchieno ◽  
...  
Keyword(s):  
Interlayer Space ◽  
X Ray Diffraction ◽  
Batch Mode ◽  
Nickel Ions ◽  
X Ray ◽  
Modified Clay ◽  
Pseudo Second Order ◽  
Oxalate Ions ◽  
Double Hydroxide ◽  
Clay Materials

In this study, sorption properties of a synthesized anionic clay were enhanced by the intercalation of oxalate ions in its interlayer space. The pristine and modified clay materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and thermal analysis. These techniques confirmed the presence of oxalate ions in the interlayer space of the clay. The intercalated clay was then used as a matrix for the sorption in batch mode of nickel ions in aqueous solution. The influence of a number of parameters such as contact time, pH, initial concentration of the analyte and adsorbent dosage were studied. The maximum adsorption of nickel was obtained at pH 6, that is, about 90% Ni2+ removal. The adsorbent/adsorbate equilibrium follows a pseudo-second order kinetics and best matches the Langmuir model. The modified clay was shown to be efficient matrix for the sorption of nickel ions.

Evolution structurale de la nacrite en fonction de la nature des molécules organiques intercalees

2000 ◽  
Vol 33 (6) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. Ben Haj Amara ◽  
H. Ben Rhaiem ◽  
A. Plançon
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Organic Molecules ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
Intercalation Process

Nacrite has been intercalated with two polar organic molecules: dimethyl sulfoxide (DMSO) andN-methylacetamide (NMA). The homogeneous nacrite complexes have been studied by X-ray diffraction (XRD) and infrared (IR) spectroscopy. The XRD study is based on a comparison between experimental and calculated patterns. The structures of the intercalated compounds have been determined, including the mutual positions of the layers after intercalation and the positions of the intercalated molecules in the interlayer space. It has been shown that the intercalation process causes not only a swelling of the interlayer space but also a shift in the mutual in-plane positions of the layers. This shift depends on the nature of the intercalated molecules and is related to their shape and the hydrogen bonds which are established with the surrounding surfaces. For a given molecule, the intercalation process is the same for the different polytypes of the kaolinite family. These XRD results are consistent with those of IR spectroscopy.

scholarly journals Ion Coordination and Chelation in a Glycolated Polymer Semiconductor: Molecular Dynamics and X-Ray Fluorescence Study

2020 ◽  
Author(s):  
Micaela Matta ◽  
Ruiheng Wu ◽  
Bryan D. Paulsen ◽  
Anthony Petty ◽  
Rajendar Sheelamanthula ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Figure Of Merit ◽  
Hole Mobility ◽  
Semiconducting Polymer ◽  
Polymer Microstructure ◽  
X Ray ◽  
Polymer Semiconductor ◽  
Full Study ◽  
Cation Coordination ◽  
Dynamics Simulations

<p>Organic electrochemical transistors (OECTs) are based on the doping of a semiconducting polymer by an electrolyte. Due to their ability to conjugate volumetric ion penetration with high hole mobility and charge density, polythiophenes bearing glycolated side chains have rapidly surged as the highest performing materials for OECTs; amongst them, p(g2T-TT) is amongst those with the highest figure of merit. While recent studies have shown how different doping anions tend to affect the polymer microstructure, only a handful of electrolytes have been tested in mixed conduction devices. Our work provides an atomistic picture of the p(g2T-TT) -electrolyte interface in the ‘off’ state of an OECT, expected to be dominated by cation-polymer interactions. Using a combination of molecular dynamics simulations and X-ray fluorescence, we show how different anions effectively tune the coordination and chelation of cations by glycolated polymers. At the same time, softer and hydrophobic anions such as TFSI and ClO<sub>4</sub> are found to preferentially interact with the p(g2T-TT) phase, further enhancing polymer-cation coordination. Besides opening the way for a full study of electrolyte doping mechanisms in operating devices, our results suggest that tailoring the electrolyte for different applications and materials might be a viable strategy to tune the performance of mixed conducting devices.</p>

scholarly journals Mechanical Activation of Smectite-Based Nanocomposites for Creation of Smart Fertilizers

2022 ◽  
Vol 12 (2) ◽  
pp. 809
Author(s):  
Maxim Rudmin ◽  
Santanu Banerjee ◽  
Boris Makarov ◽  
Kanipa Ibraeva ◽  
Alexander Konstantinov
Keyword(s):  
Electron Microscopy ◽  
Interlayer Space ◽  
Soil Leaching ◽  
X Ray Diffraction ◽  
Activation Time ◽  
Release Rates ◽  
X Ray ◽  
Weight Losses ◽  
Transmission Electron ◽  
Scanning Electron

This research presents the mechanical creation of smart fertilizers from a mixture of smectite and urea in a 3:2 ratio by using the planetary milling technique. The smectite–urea composites show intercalation between urea and mineral, which increases steadily with increasing activation time. A shift of X-Ray Diffraction basal reflections, intensities of Fourier transform infrared spectroscopy (FTIR) peaks, and weight losses in thermogravimetric analysis (TG) document the systematic crystallo-chemical changes of the composites related to nitrogen interaction with activation. Observations of the nanocomposites by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) corroborate the inference. Nitrogen intercalates with smectite in the interlayer space and remains absorbed either within micro-aggregates or on the surface of activated smectites. Soil leaching tests reveal a slower rate of nitrogen than that of traditional urea fertilizers. Different forms of nitrogen within the composites cause their differential release rates to the soil. The formulated nanocomposite fertilizer enhances the quality and quantity of oat yield.

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