Bentonite Research Articles

Bentonite clay/carbon matrix-based voltammetric sensor for the detection of valganciclovir

In the present investigation, an electrochemical sensor based on bentonite clay (BNC) was designed and exploited for pharmaceutical applications. Valganciclovir (VLGC) is a member of the aromatic compounds known as purines and L-valyl esters, and it is employed for treating cytomegalovirus retinitis. The overdosage leads to some adverse effects on human health; it is also found as a contaminant in the environmental samples. This demands the analytical tool to track the trace level of VLGC in clinical and environmental samples. The developed sensor (BNC/CPE) was employed in the electrochemical detection of the antiviral drug Valganciclovir (VLGC) using CV and SWV techniques. The developed sensor was employed to evaluate the physiochemical constituents of the electrochemical process by investigating the effect of scan rates on the irreversible signals of VLGC. BNC/CPE sensor shows the detection limits of 13.5 nM for VLGC with a good sensitivity of 35.22 µA µM−1 cm−2. The developed sensor was employed to detect the desired drug moiety in the urine samples, pharmaceutical drugs, spiked water, and soil samples. The good recoveries (93.64–102.11 %) demonstrating the applicability and selectivity of the sensor were supported by excipient interference investigation. Thus, the developed sensors and methods make them as a promise for future research to determine other bio-active molecules in pharmaceutical and clinical samples.

Effect of clays incorporation on properties of thermoplastic starch/clay composite bio-based polymer blends

In this study, thermoplastic starch (TPS) biofilms were developed using starch isolated from the seeds of Melicoccus bijugatus (huaya) and reinforced with bentonite clays at concentrations of 1%, 3%, and 5% by weight. Novelty of this research lies in utilizing a non-conventional starch source and enhancing properties of TPS through clay reinforcement. FTIR analysis verified bentonite’s nature of clays, while SEM analysis provided insights into morphology and agglomeration behavior. Key findings include a notable increase in biofilm thickness and elastic modulus with higher clay content. Specifically, tensile strength of biofilms improved from 2.5 MPa for pure TPS to 5.0 MPa with 5% clay reinforcement. The elastic modulus increased from 25 MPa (TPS) to 60 MPa (5% clay). Thermal stability also showed enhancement, with initial degradation temperature increasing from 110 °C for pure TPS to 130 °C for TPS with 5% clay. Water vapor permeability (WVP) tests demonstrated a decrease in WVP values from 4.11 × 10−10 g m−1 s−1 Pa−1 for pure TPS to 2.09 × 10−10 g m−1 s−1·Pa−1 for TPS with 5% clay, indicating a significant barrier effect due to clay dispersion. These results suggest that biofilms based on huaya starch and reinforced with bentonite clay have considerable potential for sustainable food packaging applications, offering enhanced mechanical and barrier properties.

Zn-doped bentonite catalysts for waste engine oil cracking: Thermal treatment offers a cleaner alternative to acid activation

This study investigates the cracking of waste engine oil (WEO) using bentonite clay (BC) activated through acid and thermal methods, as well as with Zn-doped BCs. Acid activation with 1 M HCl and Zn doping did not alter the BC catalyst’s structure. XRD and SAED analyses confirmed the crystallinity, while TEM showed partial destruction of the layered structure. XRF analysis indicated reduced Al and Si content upon Zn-doping due to high cation exchange capacity. Zn-doping decreased surface area and pore volume but increased acidic sites in acid-treated catalysts, although Zn suppressed these sites in calcined BC. Zn-doped catalysts displayed higher thermal stability. Cracking WEO at 450 °C for 45 min, with and without catalysts, yielded high liquid product recovery (72.6 %–82.8 %), primarily carboxylic acids and aromatics. This demonstrates the potential of Zn-doped BC as an effective catalyst for converting WEO into valuable products, aiding waste management and resource utilization.

An efficient bentonite clay catalyzed multicomponent synthesis of substituted spirooxindoles in water/ethanol solvent system

The present report demonstrates an efficient use of bentonite clay to bring about multicomponent synthesis of substituted spirooxindoles 4a-h in Water/ ethanol solvent system under the mild reaction conditions. Keywords: Bentonite clay, multicomponent synthesis, spirooxindoles

Effects of Bentonite Clay on Lacerated Wound: A Single Case Study from Tamil Nadu, India.

To control infection and promote healing, bentonite, a montmorillonite clay, was used topically to treat lacerate wounds. This clay has been used historically for both beauty and burn treatment. This clay possesses anti-inflammatory, antibacterial, and antioxidant qualities. Through the stimulation of collagen production, cell proliferation, and angiogenesis, bentonite clay promotes the healing of lacerations. The production of anti-inflammatory mediators was suppressed when lacerated lesions were treated with bentonite clay. It also has a significant impact on lacerated wound infection management. Bentonite clay's effects on lacerations. In Kulasekharam, Tamil Nadu, India, at the Sree Ramakrishna Medical College of Naturopathy and Yogic Sciences and Hospital, a single case study was carried out. The female participant in this study is 19 years old. Verbal consent was gained following an explanation of the study's objectives. Our research suggests that bentonite clay is an effective treatment for lacerations. It is a natural remedy. This outcome demonstrated that the treatment has a major, non-complicative impact on the healing of lacerations. Future research with bigger sample sizes is advised in order to increase generality.

Bentonite Clays Related to Volcanosedimentary Formations in Southeastern Spain: Mineralogical, Chemical and Pozzolanic Characteristics

The volcanism that took place during the Neogene in the southeastern Iberian Peninsula caused a large accumulation of volcanosedimentary materials, which were subsequently altered and transformed into bentonite deposits. The mineral composition and technical quality of these deposits have been demonstrated and established in this work. The main object of this research is the mineral, chemical and thermal characterization of the bentonites that lie in the southeastern region of Spain and to demonstrate their technical capabilities to be used as pozzolans. The first phase of characterization of the samples was carried out by X-ray diffraction (XRD), oriented aggregates (OAs), X-ray fluorescence (XRF) and thermogravimetric analysis (TGA). In the second phase, a chemical–technical quality test (CTQT) was carried out, aimed at determining reactive SiO2 and reactive CaO, whereas in the third phase, a chemical pozzolanicity test (CPT) was carried out to establish the pozzolanic behavior of the samples over two test periods: 8 and 15 days. The XRD and OA analyses showed that the bentonite samples are made up of a main phase formed by montmorillonite, quartz, plagioclase-albite and chabazite–Ca. The results obtained by XRF on the bentonite samples indicated that the SiO2 contents are high and vary between 43.33% and 64.71%, while Al2O3 ranges between 15.81% and 17.49%. The CTQT established that more than 80% of the SiO2 and CaO present in the samples are reactive, which was confirmed by the results of the chemical pozzolanicity test (CPT). The results obtained show that the bentonites in this study present technical qualities that are undoubtedly reinforced by their mineral constitution and chemical composition. These tests could become a practical guide for the selection of eco-efficient materials in the production of pozzolanic cements and environmentally friendly ceramic products.

Degradation by photo-Fenton process using Fe-clay as heterogeneous catalyst under sunlight and microwave irradiation

This study presents a newly developed, highly efficient heterogeneous iron-based catalyst (Fe-CY), supported on treated bentonite clay (CY), designed for the degradation of methylene blue (MB) dye. The bentonite clay underwent a two-stage treatment involving physical and chemical processes to produce the designated treated clay (CY), which served as the support material for Fe-CY catalyst preparation using the wet impregnation technique. Subsequently, the performance of the resulting catalyst was assessed in a photo-Fenton reaction aimed at degrading MB dye under both solar and microwave irradiation conditions. To determine the optimal decolorization conditions, several variables, including catalyst dosage, H2O2 quantity, pH, and initial MB concentration in the reaction system, were systematically investigated. Miscellaneous characterization techniques were employed to assess the support, and prepared catalyst. X-ray diffraction (XRD) was used to determine crystallinity, scanning electron microscopy (SEM) to analyze morphological structure, Fourier-transform infrared spectroscopy (FTIR) to identify surface functional groups, energy dispersive X-ray (EDX) analysis for the purpose of elemental analysis, and Brunauer-Emmett-Teller (BET) for analyzing the textural properties. The experimental findings highlight the remarkable effectiveness of the catalyst in degrading methylene blue (MB). Upon exposure to sunlight and microwave irradiation, the catalyst achieved substantial MB color removal rates of 99.5% and 95.5% within 180 and 8 min, respectively. Moreover, the stability of the catalyst was evaluated across three consecutive cycles, revealing a sustained removal efficiency of 83.05%. Finally, a comprehensive investigation into the mechanism behind methylene blue (MB) removal was conducted, revealing insights into the unique catalytic properties of the Fe-clay catalyst.

Biopolymer and Gypsum Added Na Bentonite for a More Effective Clay Liner

AbstractBentonite soil is frequently utilized as a compacted clay liner, which is a critical component of municipal waste landfill systems. This study aims to investigate the feasibility of treating sodium bentonite (NAB) with natural biopolymers to obtain an effective clay liner. The NAB was treated with three biopolymers: sodium alginate (SA), agar gum (A), and xanthan gum (X), at different replacement percentages (2%, 4%, 6%, and 8%). Additionally, an investigation was conducted to determine the extent to which replacing 50% of these additives with gypsum (G) would improve the biopolymer treatments. Fourier-transform infrared spectroscopy (FTIR), pH, one-dimensional swelling, and unconfined compressive strength (UCS) were carried out in this study. The FTIR results indicated the presence of intermolecular hydrogen bonding when NAB was treated with biopolymers and gypsum, which is crucial for enhancing the UCS. Furthermore, the thermal treatment of biopolymers significantly contributes to improving the UCS. Among the various biopolymers tested, agar gum demonstrated the most significant improvement, specifically, replacing 8% of the NAB with agar gum resulted in a 55% increase in UCS. Volume change behavior was most influenced by replacement of NAB with gypsum by 8%, which reduced the vertical swelling to 21% as opposed to 79% for the untreated NAB. The use of SA conversely resulted in an increased vertical swelling of 91%.

Synthesis and characterization of natural rosin-modified silica nanocomposite and its green multifunctional applications for drilling fluid

The increasing energy demand and environmental pressure require the utilization of high-performance and eco-friendly drilling fluid materials for oil/gas exploration. Herein, a green nanocomposite involving the core structure of silica (SiO2), the resin shell structure of rosin dehydroabietic acid (DHAA) derivative [poly(DHAA-co-styrene) (PDS)], and the crown structure of hydrophilic layer [crosslinked poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-N, N-dimethylacrylamide) (CAD)] was prepared through semi-continuous emulsion polymerization and utilized as a high-performance and multifunctional additive for drilling fluid. The optimal composition of core, shell and crown was determined to be 0.3: 10: 2 in mass, and the DHAA component accounted for 50 wt% in the shell structure and the molar ratio of 2-acrylamido-2-methyl-1-propanesulfonic acid and N, N-dimethylacrylamide in the crown was 3:7. The core-shell-crown nanocomposite (SiO2-PDS-CAD) exhibited a well-organized multi-layered nanostructure with an effective encapsulation of PDS on nano-SiO2 and CAD on PDS, facilitating a uniform nano-dispersion of SiO2-PDS-CAD. The bulky copolymerized rosin-based segments coupled with nano-SiO2 resulted in high thermal stability of SiO2-PDS-CAD and broadened the softening point of raw rosin from 87°C to 141°C. Meanwhile, the environmental assessments of acute toxicity and biodegradability showed that SiO2-PDS-CAD was nontoxic and readily biodegradable, and the higher incorporation of rosin components enabled SiO2-PDS-CAD more biodegradable in contrast to the non-biodegradability of the analog without rosin. Moreover, SiO2-PDS-CAD showed versatile functions in bentonite-based drilling fluid by maintaining high yield points, lowering fluid loss and enhancing nano-porous plugging capacity (100–400 nm), especially at elevated temperatures (140–180°C). A maximum increment of 1200 % on yield point occurred after aging 170°C, and the highest improvement of approximately 72 %-75 % on fluid loss occurred at 150–180°C. It also could effectively inhibit clay swelling and decrease the lubrication coefficient. The enhancement mechanism was revealed to be the core-shell-crown synergistic effects, in which the hydrophilic crown contributed to the dispersion stability of SiO2-PDS-CAD and affinity with bentonite clay, and the rigid bridging of core and flexible deformation of rosin shell strengthened the interparticle interactions. The study highlighted a novel strategy for preparing high-value-added rosin-based biomass material for green multifunctional applications in water-based drilling fluids.

Adsorption of Bichromate and Arsenate Anions by a Sorbent Based on Bentonite Clay Modified with Polyhydroxocations of Iron and Aluminum by the "Co-Precipitation" Method.

The physicochemical properties of natural bentonite and its sorbents were studied. It has been established the modification of natural bentonites using polyhydroxoxides of iron (III) (mod.1_Fe_5-c) and aluminum (III) (mod.1_Al_5-c) by the "co-precipitation" method led to changes in their chemical composition, structure, and sorption properties. It was shown that modified sorbents based on natural bentonite are finely porous (nanostructured) objects with a predominance of pores of 1.5-8.0 nm in size. The modification of bentonite with iron (III) and aluminum compounds by the "co-precipitation" method also leads to an increase in the sorption capacity of the obtained sorbents with respect to bichromate and arsenate anions. A kinetic analysis showed that, at the initial stage, the sorption process was controlled by an external diffusion factor, that is, the diffusion of the sorbent from the solution to the liquid film on the surface of the sorbent. The sorption process then began to proceed in a mixed diffusion mode when it limited both the external diffusion factor and the intra-diffusion factor (diffusion of the sorbent to the active centers through the system of pores and capillaries). To clarify the contribution of the chemical stage to the rate of adsorption of bichromate and arsenate anions by the sorbents under study, kinetic curves were processed using equations of chemical kinetics (pseudo-first-order, pseudo-second-order, and Elovich models). It was found that the adsorption of the studied anions by the modified sorbents based on natural bentonite was best described by a pseudo-second-order kinetic model. The high value of the correlation coefficient for the Elovich model (R2 > 0.9) allows us to conclude that there are structural disorders in the porous system of the studied sorbents, and their surfaces can be considered heterogeneous. Considering that heterogeneous processes occur on the surface of the sorbent, it is natural that all surface properties (structure, chemical composition of the surface layer, etc.) play an important role in anion adsorption.

Surface Modification of a Zeolite Microfiltration Membrane: Characterization and Application to the Treatment of Colored and oily Wastewaters

Membrane-based technologies used for water treatment can be an excellent alternative to handle wastewater including both conventional and emerging pollutants as they can provide technological (e.g., high quality of treated water) and economic (e.g., small footprint and low unit cost of production) advantages over other water treatment processes. Recently, low cost ceramic membranes fabricated from natural resources like kaolinitic clay, bentonite clay, phosphate are increasingly used owing to their low-cost starting materials, low sintering temperature and their excellent additional properties. Moreover, the modification of the surface by grafting process provides membranes appropriate for low UF process (dp < 10 nm) and suitable for micropollutants removal at relatively high permeate flux value which can be maintained during filtration due to antifouling characteristics of the UF active layer. In this work, the surface of microfiltration membranes made from natural zeolite was chemically modified by grafting with 1 H, 1 H, 2 H, 2 H-perfluorodecyltriethoxysilane molecule named PFAS. Various characterization methods and techniques, including scanning electron microscopy (SEM), mercury porosimetry, FTIR, TGA, and contact angle, were used to check the properties of the membranes surface before and after grafting. The grafted membranes pore size and porosity were reduced, as proved by SEM images. The determination of the water permeability shows a reduction from 1218 L.h−1.m−2.bar −1 to 204 L.h−1.m−2.bar −1 which confirm the surface densification. The application of the grafted membrane to the treatment of Indigo Blue (IB) colored solution and oily wastewater was investigated to evaluate the performances of this membrane in terms of permeate flux and pollutants retention. The filtration results revealed a good retention of color and oil, exceeding 95% for both parameters. Therefore, it is interesting to recommend this new low-cost membrane for the treatment of industrial wastewater containing recalcitrant pollutants such as color. The study of the effect of the treated colored solution on plant growth, shows that the presence of some residual nutrients required for crops growth, might make the IB treated water beneficial for irrigation purposes.

Calcined biomass-bentonite composites as eco-friendly adsorbents for the treatment of toxic anionic and cationic dye wastewater

Adsorption is a suitable technique for decontamination of organic dye wastewaters. Herein, we comparatively investigated the adsorption performance of bentonite (BEN) and its modification with groundnut shell (BGS) and palm kernel shell (BPS) for methylene blue (MB) and congo red (CR) dyes removal from aqueous solution. BGS and BPS were prepared by calcination at 300 °C for 6 h and were characterized using BET, SEM, EDS and FTIR to determine their textural properties, morphologies, elemental compositions, and functional groups. The BET surface examination revealed that the surface area of BEN was enhanced from 78 m2/g to 195 m2/g and 141 m2/g after modification with groundnut shell (BGS) and palm kernel shell (BPS), respectively. The adsorption process in a batch system was subjected to comprehensive experimentation to investigate the effect of adsorbent dosage, contact time, temperature, initial concentration, and pH. The adsorption was fitted to adsorption isotherm and kinetic models and the results revealed that the adsorption process of BEN, BGS, and BPS towards MB and CR adsorption can be best described by Temkin, Freundlich and pseudo-second order kinetic models. The adsorption capacities (qmax) for uptake of MB by BEN, BGS and BPS are 10.61, 10.85 and 10.93 mg, while CR exhibited 8.83, 6.87 and 5.86 mg/g, respectively. The thermodynamics study revealed that the adsorption process was spontaneous, feasible, endothermic in nature. The adsorption process is governed by electrostatic attraction with the involvement of physical and chemical adsorption. This study suggests that biomass-modified bentonite is a sustainable, cost-effective, non-toxic, and greener approach for eliminating MB and CR from aqueous solution. Furthermore, the modification method does not only achieve substantial removal of MB and CR dyes, but also offers considerable energy savings and operational cost reductions in real-time based on water quality data. This study does present a novel, sustainable approach to improve natural water treatment efficiency and compliance.

Tough and temperature-tolerance cellulose/polyacrylic acid/bentonite hydrogel with high ionic conductivity enables self-powered triboelectric wearable electronic devices

Solid-state zinc-ion hybrid supercapacitors (ZHSCs) featuring hydrogel electrolytes have become ideal for large-scale flexible energy storage. However, existing polyacrylic acid (PAA) hydrogel electrolytes often lack the combined traits of ionic conductivity, mechanical robustness, and temperature tolerance. Herein, a versatile PAA-based hydrogel electrolyte (ACBH-Zn) containing a ZnCl2-cellulose solution and bentonite (BT) is delivered, facilitated by cooperative coordination bonds and hydrogen bonds. The coordination bonds between Zn2+ and −COOH of PAA, in conjunction with cellulose and BT, alongside the abundant hydrogen bonds within cellulose and PAA, are conducive to upgrading mechanical strength and ionic conductivity, while the BT's lamellar structure further provides sufficient ion migration channels. Consequently, the ACBH-Zn showcases exceptional mechanical properties, satisfying ionic conductivity (88.9 mS cm−1), and excellent temperature tolerance at −60 °C (30.3 mS cm−1). The ACBH-ZHSC, when assembled, attains a remarkable maximum energy density (323.4 Wh kg−1), maintaining an impressive capacity retention rate (92 %) even after undergoing 10,000 cycles at 10.0 A g−1. Furthermore, the assembled self-powered triboelectric wearable electronic device effectively converts mechanical energy from human movement into electrical energy, enabling efficient storage and utilization, and offering promising insights into the application of flexible wearable devices.

Reflection coefficient of a natural sodium bentonite in aqueous mixed electrolyte solutions: positive and negative anomalous osmosis

A natural sodium bentonite was tested in the laboratory to measure its reflection coefficient, ω, in equilibrium with mixed aqueous solutions of sodium chloride (NaCl) and potassium chloride (KCl), with the aim of assessing the relative contribution of chemico-osmosis and diffusion induced electro-osmosis to the non-hydraulic component of the liquid flux in the presence of two cationic species, which diffuse at different rates in the pore solution. The former chemico-osmotic contribution is only related to the ionic partition effect in the bentonite pores, and causes ω to vary in the 0 to 1 range, whereas the latter electro-osmotic contribution is controlled by the diffusion potential, which spontaneously builds up across the bentonite layer in response to the different aqueous-phase diffusion coefficients of the ionic species. The theoretical interpretation of the obtained test results demonstrated that chemico-osmosis was the major contribution to ω when the testing solutions only comprised KCl. However, significant deviations in the values of ω from those expected for pure chemico-osmosis were observed for mixtures of NaCl and KCl, with both negative ( ω = −1.234) and positive ( ω = 1.040) anomalous values of the reflection coefficient, resulting from the enhanced influence of diffusion induced electro-osmosis.

Dynamics of water adsorption on SAPO-34: Comparison of three adsorbent bed configurations of adsorption chillers

Intensification of the adsorption dynamics is a strategic way to make adsorption chillers and heat pumps more competitive with conventional vapour compression systems. This can be achieved by consolidating the adsorbent bed with a heat exchanger to enhance heat transfer. This work investigates the dynamics of water adsorption on a commercial adsorbent SAPO-34 for three bed configurations, namely, a reference bed consisting of a monolayer of loose beads located on an aluminium plate, and two consolidated beds – a monolayer of beads glued to the plate, and a homogeneous coating of the plate prepared with binder. The morphology and texture of the prepared beds were studied by optical and scanning electron microscope techniques as well as by low temperature nitrogen adsorption. Six binders involved, both organic (hydroxyethyl cellulose, polyvinylpyrrolidone, polyaniline) and inorganic (heat-conductive compound CPTD, bentonite clay, colloidal silica sol), produced varying effects. It was found that the most preferred configuration involves SAPO beads glued to the plate with bentonite for which the heat transfer was enhanced by a factor of 1.2–1.7 while maintaining sufficient mass transfer. The effective heat transfer coefficient was measured for the most promising binders and selected configurations, and varied between 120 and 248 W/(m2 K). The heat transfer acceleration permitted the specific cooling power (at a conversion of 0.8) to increase from 2.7 kW/kg for loose beads of 0.8–0.9 mm size to 3.5 kW/kg for the same beads bound with bentonite. Thus, gluing pre-made commercial adsorbent beads with heat-exchanger with suitable binders presents a simple and promising method to enhance the adsorption dynamics, resulting in a more compact design of adsorption chillers.

Selective recovery of esterase from Trichoderma harzianum through adsorption: Insights on enzymatic catalysis, adsorption isotherms and kinetics

In recent years, numerous attempts have been made to develop a low-cost adsorbent for selectively recovering industrially important products from fermentation broth or complex mixtures. The current study is a novel attempt to selectively adsorb esterase from Trichoderma harzianum using cheap adsorbents like bentonite (BT), activated charcoal (AC), silicon dioxide (SiO2), and titanium dioxide (TiO2). AC had the highest esterase adsorption of 97.58% due to its larger surface area of 594.45 m3/g. SiO2 was found to have the highest selectivity over esterase, with an estimated purification fold of 7.2. Interestingly, the purification fold of 5.5 was found in the BT-extracted fermentation broth. The functional (FT-IR) and morphological analysis (SEM-EDX) were used to characterize the adsorption of esterase. Esterase adsorption on AC, SiO2, and TiO2 was well fitted by Freundlich isotherm, demonstrating multilayer adsorption of esterase. A pseudo-second-order kinetic model was developed for esterase adsorption in various adsorbents. Thermodynamic analysis revealed that adsorption is an endothermic process. AC has the lowest Gibbs free energy of −10.96 kJ/mol, which supports the spontaneous maximum adsorption of both esterase and protein. In the desorption study, the maximum recovery of esterase from TiO2 using sodium chloride was 41.34 %. Unlike other adsorbents, the AC-adsorbed esterase maintained its catalytic activity and stability, implying that it could be used as an immobilization system for commercial applications. According to the kinetic analysis, the overall rate of the reaction was controlled by reaction kinetics rather than external mass transfer resistance, as indicated by the Damkohler number.

Direct partial oxidation of low-concentration methane to methanol with copper-based clay catalysts

Partial oxidation of methane to methanol (POMM) is an economic and environmental technology, especially for utilizing low-concentration methane resources in the explosive range. In this paper, mineral clays like sepiolite (SEP), attapulgite (ATP), montmorillonite (MMT), bentonite (BEN), kaolin (KAO) and diatomite (DIA) were used as supports to prepare copper-based clay catalysts by impregnation method and their performance in continuous direct POMM with O2 as oxygen source were tested. The methanol yields of these catalysts at 320 °C with feed ratio of CH4: O2: H2O = 2: 1: 8 exhibited the following order: Cu/KAO (145.26 μmol/gCu/h) > Cu/ATP (74.18 μmol/gCu/h) > Cu/SEP (63.99 μmol/gCu/h) > Cu/MMT (51.59 μmol/gCu/h) > Cu/DIA (42.29 μmol/gCu/h) > Cu/BEN (39.64 μmol/gCu/h). This demonstrated that copper-based clay catalysts were promising for use in POMM considering their economy and environmental acceptability. Additionally, these copper-based clay catalysts were characterized and it was found that different clays could tailor the interaction of Cu species with supports, alter the reducibility and surface acidity, thereby changing the methanol yield. What's more, it was confirmed that the superior methanol yield of Cu/KAO was attributed to its relatively more [Cu2O)]2+ sites with Cu–O, Cu–Si/Al and Cu–Cu coordination structures similar to that of copper-based zeolite catalysts.

Evaluating bentonite clay’s potential in protecting intestinal flora and alleviating pseudomembranous colitis following antibiotic usage

As the most commonly used drugs, antibiotics have several adverse effects. When intravenous broad-spectrum antibiotics are administered for infections outside the gut, they are also released into the gut, upsetting the natural balance of flora and potentially causing opportunistic infections there. Pseudomembranous colitis induced by the excessive growth of Clostridioides difficile following antibiotic administration and disruption of the normal gut flora is a main consequence of antibiotic therapy. Unfortunately, effective strategies to mitigate the damage caused by antibiotics to the microbiota remain elusive, with limited information available on the subject. Several studies have examined the effects of enzymatic inactivation of specific antibiotics, but non-enzymatic inactivation of antibiotics has been explored to a lesser extent, resulting in the introduction of only a restricted number of products. We believe that bentonite clay, an underutilized substance that exhibits promising features for counteracting the unfavorable effects of antibiotics has a high potential to circumvent the side effects of antibiotics. It is a cost-effective and safe and has garnered significant attention in the medical history, predominantly for its superior adsorption properties. Given the diverse characteristics of bentonite clay, capacity to protect the natural flora, antibacterial and anti-inflammatory traits, and its contribution to wound healing, it is plausible to assume that bentonite clay exhibits significant potential in mitigating the detrimental consequences of antibiotic on the natural gut microbiota and following pseudomembranous colitis. Further research is necessary to unravel the full extent of its therapeutic effects in combating this condition.

Stabilizing Zinc Anode through Ion Selection Sieving for Aqueous Zn-Ion Batteries.

Uncontrollable dendrite growth and corrosion induced by reactive water molecules and sulfate ions (SO42-) seriously hindered the practical application of aqueous zinc ion batteries (AZIBs). Here we construct artificial solid electrolyte interfaces (SEIs) realized by sodium and calcium bentonite with a layered structure anchored to anodes (NB@Zn and CB@Zn). This artificial SEI layer functioning as a protective coating to isolate activated water molecules, provides high-speed transport channels for Zn2+, and serves as an ionic sieve to repel negatively charged anions while attracting positively charged cations. The theoretical results show that the bentonite electrodes exhibit a higher binding energy for Zn2+. This demonstrates that the bentonite protective layer enhances the Zn-ion deposition kinetics. Consequently, the NB@Zn//MnO2 and CB@Zn//MnO2 full-battery capacities are 96.7 and 70.4 mAh g-1 at 2.0 A g-1 after 1000 cycles, respectively. This study aims to stabilize Zn anodes and improve the electrochemical performance of AZIBs by ion-selection sieving.

Assessing the Microbial Impact on the Performance of Bentonite Clay at Different Thermo-Hydro-Geochemical Conditions

Assessing the Microbial Impact on the Performance of Bentonite Clay at Different Thermo-Hydro-Geochemical Conditions