Porous silica products obtained by selective leaching of phlogopite using an acid solution were investigated by XRD, MAS NMR, SEM, TEM, DTA/TG, and N2 and Ar gas adsorptions. The phlogopite powder was leached by a nitric acid solution at various concentrations (0.01–10 M) at 5–150°C for 10 min–480 h. Selective leaching of the phlogopite powder became extensive when the concentration of nitric acid was >1 M. Only SiO2 remained after the treatment, the other components (MgO, Al2O3, K2O and Fe2O3) being selectively leached from the product. At higher leaching temperatures, the leaching rate became faster and the resulting maximum specific surface area of the porous silica product became larger at each leaching temperature. The porous silica products were found by SEM and TEM, to maintain their original platy particle shape even after the selective leaching. The 29Si MAS NMR spectra of the products, however, revealed that the linkage structure of SiO4 tetrahedra converted to a framework type from a layered type in the original phlogopite. The porous silica product with the maximum specific surface area (532 m2/g) was obtained by leaching in a nitric acid solution with concentration of 5 M at 90°C for 15 min. The pore-size distribution of the porous silica product was bimodal with micropores of ∼0.7 nm and mesopores of ∼4 nm. The pore size of the products changed from 0.7 nm to 4 nm and further to 6 nm with increased leaching time. The present results are discussed in relation to those reported for phlogopite by other workers.

Interlayer swelling of hydrated montmorillonite is an important issue in clay mineralogy. Although the swelling behavior of montmorillonite under ambient conditions has been investigated comprehensively, the effects of basin conditions on the hydration and swelling behaviors of montmorillonite have not been characterized thoroughly. In the present study, molecular dynamics simulations were employed to reveal the swelling behavior and changes in the interlayer structure of Na-montmorillonite under the high temperatures and pressures of basin conditions. According to the calculation of the immersion energy, the monolayer hydrate becomes more stable than the bilayer hydrate at a burial depth of 7 km (at a temperature of 518 K and a lithostatic pressure of 1.04 kbar). With increasing burial depth, the basal spacings of the monolayer and bilayer hydrates change to varying degrees. The density-distribution profiles of interlayer species exhibit variation in the hydrate structures due to temperature and pressure change, especially in the structures of bilayer hydrate. With increasing depth, more Na+ ions prefer to distribute closer to the clay layers. The mobility of interlayer water and ions increases with increasing temperature, while increasing pressure caused the mobility of these ions to decrease.

The reduction of azo dyes to less toxic and more easily biodegradable amine derivatives is an effective strategy for the treatment of industrial wastewater. The present work aimed to study the reduction reaction of azo dye Congo red (CR) catalyzed by nanoparticles (NPs) of chromium oxides (Cr2O3NPs) immobilized on bentonite in the presence of NaBH4. Cr(III) ions were intercalated using ion exchange reactions to obtain Cr-bentonite, and then the immobilized chromium cations were treated using NaBH4 leading to the formation of Cr2O3NPs-bentonite. The physicochemical properties of the samples were investigated using X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS), atomic absorption spectrometry (AAS), UV–Visible diffuse reflectance (UV–Vis DR), and Fourier-transform infrared (FTIR) spectroscopy techniques. The results showed the formation of various chromium species, in which the most dominant were chromium oxide nanoparticles, on the bentonite surface with an average particle size between 20 and 35 nm. Line-scan analysis showed a reactive catalytic surface due to the excellent distribution of Cr on the bentonite surfaces. The best-performing catalyst, Cr2O3NPs-bentonite, displayed significant catalytic activity compared to the bentonite and Cr-bentonite materials, with a full reduction time of 630 s and a rate constant, kapp, equal to 0.034 s–1. The resulting products (benzidine and sodium 3, 4-diaminonaphthalene-1-sulfonate) from the catalytic reduction exhibited low toxicity compared to the CR dye; these products are easy to use in chemical synthesis. All results collected from this work indicated that this low-cost catalyst can be exploited to eliminate other dyes from the environment.

Microporous structure in zeolite leads to diffusion limitation, which causes coke formation and is harmful to catalytic reactions. Hierarchical zeolite containing primary microporosity and secondary porosity at the meso- and macroscales has received much attention due to its enhanced mass transport. Hierarchical Y zeolites were obtained by treating NH4-Y zeolite with high-temperature calcining and acid-base leaching. The results demonstrated that the calcined zeolite showed great crystallinity after acid-base leaching. The mechanism of introduction of mesopores was demonstrated in detail. The calcination transformed framework Al to extra-framework Al and enlarged the defect by acid and alkali. The mesopores increased with the calcining temperature and holding time. The relationship between the heating rate and the removal of Al species was non-linear; a heating rate of 100°C/h exhibited good protection for the zeolite structure.

NEWMOD®, developed by R.C. Reynolds, Jr., has been an important tool for evaluating quantitatively X-ray diffraction (XRD) patterns from interstratified clay minerals for more than 20 years. However, a significant drawback to the NEWMOD® approach is that analyses are done by forward simulation, making results sensitive to user input and starting-model assumptions. In the present study, a reverse-fitting procedure was implemented in a new program, FITMOD, which automatically minimizes the differences between experimental and simulated XRD patterns. The differences are minimized by varying model parameters (such as Reichweite, crystal-size distribution, cation content, type of disorder, etc.) using the downhill simplex method. The downhill simplex method is a non-linear optimization technique for determining minima of functions. This method does not require calculation of the derivatives of the functions being minimized, an important consideration with many of the parameters in NEWMOD- type simulations. Instead, the downhill simplex method calculates pseudo-derivatives by evaluating sufficient points to define a derivative for each independent variable. The performance of FITMOD was evaluated by fitting a series of synthetic XRD patterns generated by NEWMOD+, yielding agreement factors, Rwp, of <0.3%. As long as the correct interstratified system was specified (e.g. illite-smectite), excellent fits were obtained irrespective of the starting parameters for the simulations. FITMOD was also tested using experimental XRD patterns, which gave very good fits, in agreement with previously published results. The optimization routine yields good fits for both synthetic and experimental XRD profiles in a reasonable time, with the possibility of varying all important structural parameters. FITMOD automatically provides optimum fits to experimental XRD data without operator bias, and fitting efficiency and accuracy were, therefore, significantly improved.

The widespread Balıkesir bentonite deposits within the Miocene volcano-sedimentary units in western Anatolia have economic potential; they are important raw materials for the paper and bleaching industries in Turkey. No detailed geological, mineralogical, geochemical, or genesis characterizations of these bentonite deposits have been carried out to date. The present study was undertaken to close this gap. The mineralogical characteristics of the bentonites and their parent rocks were examined using polarized-light microscopy, X-ray powder diffractometry (XRD), scanning- and transmission-electron microscopies (SEM–EDX and TEM), and chemical (ICP–AES and –MS) methods. In the bentonite deposits, smectite is associated with smaller amounts of illite, chlorite, quartz, feldspar, dolomite, calcite, opal-CT, and amphibole. The smectite was identified by sharp basal reflections at 14.42–14.93 Å. Plagioclase and sanidine crystals in volcanic units are altered and sericitized. Biotite and hornblende are partly to completely Fe-(oxyhydr)oxidized and chloritized. Smectite flakes occur on altered feldspar and mica grains and devitrified volcanic glass fragments in association with or without calcite ± dolomite crystals. Increasing Al+Fe+Mg/Si ratios with increasing degree of alteration reveal that hydration of volcanogenic grains (feldspar, mica, hornblende, glass shard) favored precipitation of smectite with montmorillonite composition, with an average structural formula: (Ca0.31Na0.05K0.08)(Al2.72Fe0.17Mg1.27Ti0.011Mn0.01)(Si7.94Al0.06)O20(OH)4. The concentration of Al2O3 and MgO and increase of LREE/HREE ratio, and a distinct, negative Eu anomaly show that smectite was probably formed as a result of the decomposition of volcanic feldspar, mica, amphibole, and volcanic glass. Association of carbonate rocks within the smectite-rich material and the absence of chlorite and detrital materials such as rock fragments in the bentonites suggest that the bentonite deposits formed authigenetically as ‘primary bentonites’ from volcanoclastic materials deposited in a calm lacustrine–palustrine environment during an early diagenetic process.

Shales and claystones in the Permian Irati Formation consist of Al-rich or Fe-Mg clay minerals in its southern/central and northern parts, respectively. The constrasting compositions indicate particular geological and paleo-environmental conditions. The purpose of this study was to determine the conditions of formation by characterizing the black shales and claystones from different sections of the northern edge of the basin, some of which reveal the presence of intruded diabase sills.

Black shales consist of saponite or saponite-talc mixed layers, talc, lizardite, nontronite, and quartz. Green claystones are nontronite-rich but also contain lizardite, talc, and quartz. The chemical compositions of the black shale and claystones, except for one sample (POR-56), exhibit a positive correlation of the TiO2, Cr, and P2O5 contents with Al2O3, which typically results from weathering processes. The presence of saponite, nontronite, and some accessory minerals (spinel, pyroxene, native silver) suggests altered basic-ultrabasic rocks as sediment sources, consistent with the rare earth element (REE) composition being less than the Post-Archean Average Shale (PAAS) or North American Shale Composite (NASC) levels and with negative Ce and Eu anomalies. Sample POR-56 consists largely of nontronite and is anomalously rich in zircon, monazite, and apatite. Chemically, sample POR-56 is different from the black shales and claystones, being richer in Al2O3-Fe2O3, MgO-poor, and having greater REE contents than the PAAS or NASC standards. The POR-56 bed is probably a bentonite resulting from the alteration of volcanic ash in sea water (strong, negative Ce anomaly). The Zr/TiO2vs. Nb/Y relation indicates that the magmatism was andesitic. During the Upper Permian, intermediate to basic volcanic activity was recorded in the Mitu Group of the Central Andes.

Close to the diabase sill, the black shales and claystones contain saponite, talc, and lizardite but nontronite is absent. Saponite and talc crystals, however, exhibit a larger coherent scattering domain size (CSDS) and are randomly oriented with respect to the sedimentary bedding. The thermal metamorphism effect is confirmed by the presence of secondary enstatite-augite and albite crystals.

Epilepsy treatment requires anti-seizure medical formulations; available medications have various painful side effects and penetrate the brain–blood barrier poorly. A promising method is the use of natural clay nanocontainers for drug delivery through this membrane barrier. Halloysites (Hly) are biocompatible, 50-nm diameter tubes with a positively charged, hollow inner lumen and negatively charged outer shell and are available naturally. These characteristics enable them to be versatile as drug loaded ‘nano-torpedoes’ effectively penetrating cell membranes. The endothelial cells are a major cell type in the blood–brain barrier that provides for the selective permeability separating the circulating blood and allowing only the passage of glucose, water, and amino acids, but not traditional drug formulations. Nanotubes encapsulating rhodamine isothiocyanate and ionomycin penetration through the rat-brain microvascular endothelial cells followed by a prolonged 24-h drug release was demonstrated. A model membrane was set up across 0.4-μm-pore polystyrene transwell supports covered by seeding endothelial and astrocyte cells to mimic the blood–brain barrier in vivo. This barrier demonstrated a dual permeation mechanism (inter-cell accumulation and through-passing) for loaded Hlys, exploiting the potential of this nanoclay in the trans-membrane delivery of drugs. Use of Hly nanotubes as drug carriers to penetrate the brain microvascular endothelial barrier and to deliver the payload displayed a new approach for the treatment of brain diseases such as epilepsy.

A reference sample of sepiolite and products of its comminution by vibrating dry-milling have been studied using X-ray diffraction (XRD) line-broadening analysis, complementary field emission scanning electron microscopy (FESEM) images and surface area measurements. The apparent crystallite sizes determined via XRD are in agreement with observations on FESEM images. The sepiolite aggregates consist of lath-shaped agglutinations of prisms and pinacoids elongated along [001], each lath including several crystallites in that direction. The surface area magnitudes are in the range of previous experimental measurements of other sepiolites. The results obtained show the effectiveness of vibro-milling as the procedure to use for the comminution of sepiolite.

This article examines a transnational network of advocates for Kampō (traditional) medicine in Japan, occupied China, and Manchukuo during the Sino-Japanese War (1931–1945), shedding new light on collaborationism, Asianism, and the modernization of traditional medicine in East Asia. In the 1930s, despite deteriorating Sino-Japanese relations, the Kampō revival movement in Japan joined forces with the struggle to preserve traditional medicine in China. In 1938, the Association of East Asian Medicine was founded in Japan, gathering together Chinese, Korean, and Japanese advocates under the banner of ‘East Asian medicine’. This article delineates the evolution of what I call ‘medical Asianism’ and how it was institutionalized in different parts of the Japanese empire. Participants in this network differed in their priorities and ideological commitments, yet they tactfully utilized the Japanese imperial infrastructure and wartime circumstances to promote traditional medicine. Their work laid important intellectual and institutional foundations for the postwar development of traditional medicine across East Asia. This study also contributes to a more nuanced understandings of collaborationism. The type of collaboration examined in this article was preceded by a long history of intellectual exchange, based on a shared body of knowledge and morals, motivated by mutual empathy, and for a cause that was much valued in postwar Asia. As a result, unlike most Chinese collaborators who were prosecuted as ‘traitors’, protagonists in this study continued to prosper professionally and became valuable assets in the postwar rebuilding of Sino-Japanese relations.

The reactivity and stability of the edge faces of swelling clay minerals can be altered by layer charge and the stacking structure; however, these effects are poorly understood due to experimental limitations. The structure and stability of the montmorillonite {110}, {010}, {100}, and {130} edge faces with a layer charge of either y = 0.50 or y = 0.33 (e−/Si4O10) were investigated using first-principles calculations based on density functional theory. Stacked- and single-layer models were tested and compared to understand the effect of stacking on the stability of montmorillonite edge faces. Most stacked layers stabilize the edge faces by creating hydrogen bonds between the layers; therefore, the surface energy of the layers in the stacked-layer model is lower than in the single-layer model. This indicates that the estimates of edge face surface energy should consider the swelling conditions. Negative surface energies were calculated for these edge faces in the presence of chemisorbed water molecules. A high layer charge of 0.50 reduced the surface energy relative to that of the low layer charge of 0.33. The isomorphic substitution of Mg for Al increased the stability of interlayer Na ion positions, which were stable in the trigonal ring next to the Mg ions. The lowest surface energies of the {010} and {130} edge faces were characterized by the presence of Mg ions on edge faces, which had a strong cation adsorption site due to the local negative charge of the edges. The coordination numbers of O atoms around cations adsorbed to these edge faces were small in comparison to interlayers without water.

Adsorption desulfurization is a potential new method for deep desulfurization of fuel oil. The development of adsorbents with high adsorption capacity and selectivity is the core of deep adsorption desulfurization. The adsorption behavior of thiophene in MCM-41 mesoporous materials modified by various metal ions was studied in order to understand the adsorption desulfurization process of molecular sieves. The Fe-, Co-, and Zn-modified MCM-41 materials were prepared using a one-step in situ hydrothermal synthesis method. The modified MCM-41 molecular sieves maintained the mesoporous structure, and the metal ions had specific dispersion on the surface of the molecular sieves. Adsorption of thiophene on the surfaces of molecular sieves had both physical and chemical characteristics. The adsorption desulfurization performance of the modified molecular sieve was superior to that of the pure silica molecular sieve. In the simulated gasoline with sulfur content of 220 μg/g, when the amount of adsorbent used was 100 mg, the adsorptive desulfurization performance tended to be in equilibrium, and the optimum adsorption temperature was 30°C. Fe-MCM-41 and MCM-41 molecular sieves reached adsorption equilibrium after ~60 min, but the desulfurization rate of Co-MCM-41 and Zn-MCM-41 still increased slightly. The kinetic simulation results indicated that the pseudo-second-order kinetics adsorption model described well the adsorption process of thiophene on molecular sieves. The molecular sieve Fe-MCM-41 had the best desulfurization performance with an equilibrium adsorption capacity of 14.02 mg/g and the desulfurization rate was ~90%.

Very unusual rocks consisting of natrolite (>95 vol.%) ± pargasite (<5 vol.%) and rarealbite (<1 vol. %) have been discovered in the Kop mountain range, eastern Turkey. We propose to call these rocks ‘natrolitite’ and ‘pargasite natrolitite’. They were produced by Na Si metasomatism of dikes and stocks of diorite through replacement of the intermediate primary igneous plagioclase to produce natrolite. The metasomatic alteration produced concentric elliptical zones characterized by distinct mineral assemblages centered on intrusions of diorite. The Central Zone 1 consists of variably albitized diorite with preserved magmatic textures (albite ± andesine ± pargasite ± quartz). Transition Zone 2 comprises natrolite-bearing diorite (natrolite ± albite ± andesine ± pargasite ± calcite ± quartz). Marginal Zone 3 is a rock made up almost entirely of natrolite (natrolite ± pargasite ± albite ± calcite ± chlorite). Outer Zone 4 occurs along the boundary between the natrolitite and the surrounding serpentinite and consists of listvenite, a rock which comprises magnesite, quartz, calcite, mica, talc, and hematite, indicating a role for CO2 in the metasomatic reactions, consistent with the presence of calcite in the alteration zones. Zone 5 consists essentially of brecciated serpentinite with numerous hydrothermal quartz veins and calcite veins. Whole-rock compositions document an increase in Na2O, Al2O3, and H2O from the core (central zone) to themargin while CaO, MgO, and SiO2 decrease. Plagioclase abundance and composition also varies outwards from the central core rocks where it occurs as a primary magmatic phase (∼95 vol.% An41−38) to the alteration zones (<5 vol.% An32−37) due to partial to complete replacement of plagioclase by natrolite with or without rare albite. The natrolites exhibit little variation in Si/Al ratios, ranging between 1.45 and 1.61, and are similar in composition to those reported in the literature. Accompanying pargasitic amphibole also becomes progressively more sodic in composition from the core rocks to the marginal zone rocks. Our analysis indicates that albitization preceded the formation of natrolite and that the formation of natrolite, instead of other more typical alteration minerals (e.g. analcime and paragonite), reflects Na metasomatism at lower chemical potentials for Al2O3 and SiO2. Potential sources of Na could be hypersaline brines or leaching of country rocks, such as trondhjemites. The fluids were driven in hydrothermal convection cells set up by theintrusion of thediorites.

To better predict the fate and mobility of surfactants in the environment, sorption and desorption of a nonionic polyoxyethylene lauryl ether surfactant (Brij 35) by two smectites (Wyoming montmorillonite and Panther Creek smectite) and two interstratified mica-vermiculites (IMVs) were investigated by batch techniques, X-ray diffraction, and infrared spectroscopy. Maximum surfactant sorption by smectites ranged from 196 to 256 g kg−1, whereas the maximum sorption by the IMVs was indeterminate over the range of concentrations employed. Sorption by smectites was best described by the Langmuir model, but sorption by the IMVs showed an S-shaped isotherm, suggesting that cooperative sorption occurred. The surfactant was more readily desorbed from the IMVs than from the smectites in an initial wash with water. After two water washes, 65–75% of the initially sorbed surfactant was retained by the smectite, and 44–51% of the surfactant sorbed to the IMVs remained with the solid phase. In this study, basal spacing of the smectites increased to ≈17.5 Å near the sorption maximum, suggesting intercalation of surfactant molecules in the interlamellar regions of the clay. X-ray data also suggested that the surfactant molecules were oriented horizontally in the interlayer spaces. Greater surfactant sorption by the Casmectites gradually diminished the intensity of the 1630 cm−1 infrared band dues to hydration water, indicating that some water had been displaced by the surfactant. The surfactant was also sorbed by the IMV clays, but only on external surfaces and probably via interactions of micelles with the solid phase.

Quantitative analysis of the smectite-to-illite and illite-to-muscovite transformations indicates that 17–28 wt.% SiO2 and 17–23 wt.% SiO2, respectively, are liberated during these reactions, assuming that Al is conserved. Dissolution of quartz silt in shales yields up to 6–9% SiO2 in the range up to 200°C and a further 10–15% SiO2 in the 200–500°C range. For muds altered to shales at 200°C, 14–20 wt.% silica is evolved. From 200 to 500°C, a further 18–28 wt.% silica is evolved. Additional small amounts of silica may be released in the alteration of feldspar to clay and by stylolitization of quartz silt. Thus, in the burial and temperature range of diagenesis into the epizone, major quantities of silica are released from clays and by quartz dissolution in shales. Within this range of alteration, concomitant decline of whole-rock Si/Al (SiO2/Al2O3) in the transformation of smectite to illite to muscovite suggests the liberated silica migrates from the source shale. As a result, the metamorphosed shales are more micaceous and less quartzose than their progenitor muds. In the diagenetic zone and anchizone, the evolved silica is probably a major source of quartz cement in sandstones. In the epizone, evolved silica is commonly present in quartz veins in the parent rocks. Fluid-inclusion temperatures in quartz overgrowths and fracture fillings in some sandstones suggest that some cements may have been derived from downdip basinal shales and pressure solution in sandstones.

The polyphenol theory of humic-substance formation has been studied extensively; however, an alternative theory, that humic substances are formed through the condensation of amino acids and reducing sugars (Maillard reaction), has not been explored to the same extent. The general objectives of this study were to determine whether smectites and goethites catalyze the abiotic polymerization of arginine and glucose to form humic-like compounds. The effects of smectite type, saturating cation, and the degree of Al substitution in goethites on the polymerization reaction were also studied. Four cation-saturated smectites and four Al-substituted goethites were incubated abiotically with solutions containing a mixture of arginine + glucose for 21 days at 37°C. After the incubations, total C recovered ranged from 80.6 to 123.8% and from 100.5 to 105.1% for the smectite and goethite systems, respectively. At the end of the incubations, 21.4–50.3% of the added C and 16.5–90% of the added N were sorbed on the various smectites, and 6.2–9.0% of the added C and 2.3–4.6% of added N was sorbed on the goethites in a form that could not be desorbed by washing with 100 mM CaCl2. X-ray diffraction analysis indicated that some of the sorbed C was intercalated in the smectites and FTIR analysis provided evidence of new absorption bands at 1650 and 1668 cm−1, which are consistent with Maillard reaction products. Thus, it is concluded that smectites catalyze the condensation of arginine and glucose to form humic-like products. Goethites, however, have little or no ability to catalyze this reaction.

The ultrasound technique was applied to the synthesis of layered double hydroxides. The use of ultrasound in the synthesis of these compounds was studied in terms of its effect on their crystal qualities and surface properties. The crystal qualities of the compounds synthesized with ultrasound were compared with those of compounds synthesized without ultrasound to elucidate the effect of the ultrasound on the synthesis. The effect of crystal quality (crystallite size) on the adsorption behavior of humic substances was examined. The compounds synthesized under ultrasonic conditions showed a larger crystallite size and a larger adsorption capacity for humic substances than those synthesized without ultrasonic treatment. The degree of adsorption correlated well with crystal quality.

The Church of Ireland General Synod had been held online in 2021 and in person in 2022. This year – the third meeting of the triennium – the first two days were held in Clayton White's Hotel, Wexford (Friday 12 May and Saturday 13 May) with day 3 taking place remotely on the evening of Tuesday 16 May. (Another evening, Thursday 18 May, had also been set aside for meeting but this was not required.)