Synthesized zeolites are extremely important as industrial minerals and are most commonly prepared using organic templates. Because these organic templates present undesirable environmental hazards, a synthesis method which avoids their use is desirable. The objective of the current study was to develop such a synthesis method. Zeolite NaY was synthesized hydrothermally starting from a mixture of 1.0 Al2O3:10 SiO2:4.6 Na2O:180 H2O molar gel composition, without adding any organic additives. Experiments were carried out to investigate the effects of molar compositions including water content (H2O/SiO2), crystallization conditions including temperature, and time on the crystal size and yield of NaY-type zeolite. The results showed that increasing the crystallization time from 5 to 12 h increased the crystal size, while increasing the crystallization temperature from 80 to 100°C also increased crystallinity. The crystal species of zeolite NaY were characterized by X-ray diffraction, X-ray fluorescence, and scanning electron microscopy analysis. Zeolite NaY crystals in the size range 25–150 nm were synthesized successfully over a period of 8 h at 100°C.

High temperature and a large salt content weaken the surface hydration ability of clay particles in drilling fluid, reduce zeta potential, agglomerate clay particles, increase particle size, and destroy the stability of drilling mud. A filtrate reducer is required, therefore, to maintain the zeta potential of the clay, prevent the agglomeration of clay particles, and maintain good performance of the drilling mud at high temperature and high salt content. To prepare temperature- and salt-resistant polymer filtrate reducer, a betaine monomer was synthesized and copolymerized with a conventional monomer. A betaine monomer 3-(dimethyl (4-vinyl benzyl) ammonia) propyl sulfonate (DVBAPS) was synthesized and then used to create a copolymer filtrate reducer. The copolymer filtrate reducer, referred to as PAAAND, was prepared by free radical copolymerization with 2-acrylamide-2-methylpropane sulfonic acid, acrylic acid, N-vinyl pyrrolidone, acrylamide, and DVBAPS. The optimum synthesis conditions were determined by single factor evaluation, and the chemical structure of the PAAAND was confirmed by Fourier-transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. Results from particle-size distribution and zeta-potential measurements showed that PAAAND increased the zeta potential of clay particles and the distribution width of particles size, which served to maintain the stability of the drilling mud under high-temperature and high-salt conditions. The results of scanning electron microscopy showed that PAAAND made the filter cake formed by clay particles smoother and denser, which reduced filtration loss. The reduction in filtrate loss continued even after aging at high temperature, and, thus, PAAAND performed better than commercial products.

Remembered largely for the controversial rebuilding of the Bank of England and for his role in the construction of New Delhi, Herbert Baker (1862–1946) was responsible for architecture in the wider British empire as well as his native England. This article appraises ways in which Baker and his work linked these spheres through an analysis of India’s High Commission in London, India House (1928–30), the first extended scholarly account of the building. In doing so, it focuses on how architecture designed by Baker during the interwar period evoked the assumption by India of ‘dominion status’, a label applied to imperial regions deemed to have attained a position of equality alongside Britain on the basis of their constitutional development. The article locates the new High Commission at the convergence of an interwar imperial vision emphasising the status of the dominions and India’s path towards independence, contributing to an architectural history of British imperialism as urged for in recent years. Constructed at the heart of the imperial capital, India House was a highly visible declaration of India’s transition from a position of dependence to one approaching parity with Britain and the ‘old’ or ‘white’ dominions. As well as substantiating Baker’s commitment to India’s envisaged future as a dominion, the building shows significant consistencies of approach and intent when set against contemporaneous work in New Delhi, manifesting interconnections between the two spaces and the pivotal role of the architect in linking them.

Photo-assisted selective catalytic reduction (photo-SCR) has been considered as a promising strategy for NOx removal in recent decades. The purpose of the present work was to test the effectiveness of La1–xPrxCoO3, supported on the surface of natural palygorskite (Pal) by a facile sol-gel method, as a photo-SCR for the removal of NOx from wastewaters. The structure, acidity, and the redox property of the prepared La1–xPrxCoO3/Pal nanocomposite were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). Density functional theory (DFT) calculations were employed to determine the valence bands. The La1–xPrxCoO3/Pal catalysts were then tested for SCR removal of NOx with the assistance of photo-irradiation. The photo-SCR results revealed that the NOx conversion and the N2-selectivity were greatly improved by this method and reached >95% when carried out at the relatively low temperature of 200°C and with the Pr doping at x = 0.5. The improvements were attributed to the co-precipitation of a PrCoO3 phase as in a solid solution forming a coherent heterojunction of PrCoO3/La0.5Pr0.5CoO3 on the Pal surface.

Compacted bentonite–sand mixture is proposed widely as backfill in geological repositories for disposal of radioactive waste in many countries because this material has significant swelling capacity and low water permeability. Development of the swelling pressure of backfills upon hydration is related closely to the stability of the host rock in the geological repository. No systematic experimental studies have been carried out to explore the effect of a water phase on the swelling pressure and water retention of bentonite–sand mixtures with insignificant osmotic suction. The objective of the current study was to examine experimentally the influence of a water phase involving liquid water and water vapor on swelling pressure and water retention of a bentonite–sand mixture with insignificant osmotic suction. Swelling-pressure tests with suction control and water-retention measurements under constant-volume conditions were performed on the compacted bentonite–sand mixture with a dry density of 1.80 g/cm3. Osmotic and vapor equilibrium techniques were used to make identical specimens adsorb liquid water and water vapor, respectively. The experimental results showed that the water phase had almost no effect on the swelling-pressure patterns of the unsaturated bentonite–sand mixture upon hydration over a suction range from 27 to 3 MPa. The swelling pressure increased significantly with decreasing suction from 27 to 3 MPa, regardless of the mixture adsorbing either the liquid water or water vapor. Nevertheless, the water phase had a considerable impact on both the swelling pressure and water retention of the unsaturated bentonite–sand mixture upon hydration over the same suction range. For a given value of suction in the range above, the swelling pressure and the water content of the bentonite–sand upon adsorption of liquid water were greater than those upon adsorption of water vapor. The influence of the water phase on the swelling pressure and the water retention of the bentonite–sand mixture with insignificant osmotic suction is related mainly to the hydration or swelling mechanism of Ca-rich bentonite.

The nature of component layers of mixed-layer illite-smectite and their possible evolution in the course of illitization have been debated since the 1960s. The present study is a new attempt to solve these problems, using samples collected from diverse geological formations around the world. Twenty three purified illite-smectites from bentonites and hydrothermal rocks, covering the complete range of expandability, were analyzed chemically, including ${\text{NH}}_4^{+}$\$\end{document} determination, and their structural formulae were calculated. The exchangeable cations (EXCH) were plotted vs. the fixed cations (FIX) yielding the following experimental regression:$\text{EXCH}=-0.43\times \text{FIX}+0.41\left({\text{R}}^2=0.98\right)$\$\end{document}

FIX and EXCH depend on the charge of the illite (Qi) and smectite (Qs) interlayers, and the fractions of these interlayers in the bulk clay leading to: $\text{EXCH}=-Q_{\text{s}}\text{/}{Q}_{\text{i}}\times \text{FIX}+Q_{\text{s}}$\$\end{document}

Analysis of these relations and independent measurements of the total specific surface area (TSSA) indicate that the layer charges of both types do not change in the course of illitization. The smectite layer charge is equal to 0.41 and the illite layer charge is equal to 0.95 per O10(OH)2. End-member illite has a well defined composition that is close to intermediate between muscovite and phengite, with fixed cations content greater than that specified in the AIPEA classification of layer silicates:${\text{FIX}}_{0.95}\left({\text{Si}}_{3.25}{\text{Al}}_{0.75}\right)\left({\text{Al}}_{1.81}{\text{Fe}}_{0.01}{\text{Mg}}_{0.19}\right){\text{O}}_{10}{\left(\text{OH}\right)}_2$\$\end{document}

The established relationship allows the calculation of the mean number (N) of 2:1 layers in all fundamental particles and also the fraction of smectitic layers (fs) from FIX:$N=Q_{\text{i}}\text{/}(Q_{\text{i}}-\text{FIX})f_{\text{s}}=(Q_{\text{i}}-\text{FIX})\text{/}{Q}_{\text{i}}$\$\end{document}

N and fs can be used to calculate TSSA, and all three parameters can also be calculated from cation exchange capacity and from X-ray diffraction peak positions, utilizing the regressions established here.

High-temperature oxide-melt solution calorimetry and acid-solution calorimetry were used to determine the heat of dissolution of synthetic goethite with particle sizes in the range 2–75 nm and measured surface areas of 30–273 m2/g (27–240 × 103 m2/mol). Sample characterization was performed using X-ray diffraction, Fourier transform infrared spectroscopy, the Brunauer, Emmett and Teller method and thermogravimetric analysis. Water content (structural plus excess water) was determined from weight loss after firing at 1100°C. Calorimetric data were corrected for excess water assuming this loosely adsorbed water has the same energetics as bulk liquid water. The enthalpy of formation was calculated from calorimetric data using enthalpies of formation of hematite and liquid water as reference phases for high-temperature oxide-melt calorimetry and using enthalpy of formation of lepidocrocite for acid-solution calorimetry. The enthalpy of formation of goethite can vary by 15–20 kJ/mol as a function of surface area. The plot of calorimetric data vs. surface area gives a surface enthalpy of 0.60±0.10 J/m2 and enthalpy of formation of goethite (with nominal composition FeOOH and surface area = 0) of −561.5±1.5 kJ/mol. This surface enthalpy of goethite, which is lower than values reported previously, clarifies previous inconsistencies between goethite-hematite equilibrium thermodynamics and observations in natural systems.

The clay minerals formed in chilled margins and massive crystallized inner parts of three basalt-hawaiite bodies of Mururoa Atoll (French Polynesia) exhibit contrasting textures. Glass alteration textures are observed around fractures crosscutting the quenched margins: Fe-rich clays grow inward into the glass (retreating surface) while Mg-rich clays grow outward (open space). The textures of clay deposits filling the diktytaxitic voids (mesostasis) in the massive inner parts of the three volcanic bodies are different: unoriented clay matrix with embedded euhedral apatite and pyroxene microcrysts (submarine flow); pallisadic clays coating the void walls and the crystal surfaces of apatite and K-feldspar microcrysts (subaerial flow); and clay muffs covering all the apatite needles, with the central part of the void remaining empty (dike). The unoriented texture could result from the alteration of a glass precursor concomitant with the olivine phenocrysts (clay pseudomorphs). However, such an alteration implies important chemical transfers which are not observed. The pallisadic and muff textures form through heterogeneous nucleation on the solid surfaces and crystal growth from a saline solution. No glass precursor existed. As the center of the diktytaxitic voids in the dike is empty, the residual liquid was probably boiling. The amounts of light rare earth elements (LREE), Sr, and the most incompatible elements are greater in clays from diktytaxitic voids relative to the amounts formed in the altered glass of the chilled margins. Thus, diktytaxitic clays formed from a residual liquid which gave either an evolved glass or a saline solution after cooling (fractionation process). The δ18O variation vs. loss on ignition (LOI) indicates that sea water was involved either in rock alteration or magma contamination. This is confirmed by the 87Rb/86Sr ratio of bulk rocks and clay fractions from the quenched and massive inner parts of the three volcanic bodies which do not fit with the 11.5 Ma isochron indicating that the Rb-Sr system was not closed at any stage during the magmatic history.

Model spent cetyltrimethylammonium bromide (CTMAB)-bentonite, and cetyl pyridinium chloride (CPC)-bentonite used for sorbing p-nitrophenol (PNP) from wastewater, as well as virgin CTMAB-bentonite and CPC-bentonite, were employed as the starting materials to prepare porous clay heterostructures (PCHs). The BET surface areas and total pore volumes of the PCHs based on these spent and virgin organobentonites (PNP-CTMAB-PCH, CTMAB-PCH, PNP-CPC-PCH and CPC-PCH) are 661.5 m2/g and 0.25 cm3/g, 690.4 m2/g and 0.27 cm3/g, 506.3 m2/g and 0.30 cm3/g, and 525.4 m2/g and 0.30 cm3/g, respectively. These values approximate those of activated carbon (AC), at 731.4 m2/g and 0.23 cm3/g, and are much larger than those of bentonite and CTMAB-bentonite, at 60.9 m2/g and 0.12 cm3/g, and 3.7 m2/g and 0.0055 m2/g, respectively. The PCHs have slightly higher adsorption capacities for benzene and CC14 than AC at higher relative pressures despite their comparatively lower benzene and CC14 adsorption capacity at lower relative pressures. The existence of PNP in organobentonites also enhances the volatile organic compounds (VOCs) adsorption capacity of PCHs at lower adsorbate concentrations, although some adsorption capacity is lost at higher concentrations. The hydrophobicity order of the adsorbents is: CTMAB-bentonite > AC > PCHs > bentonite. The micro- to mesoporous pore sizes, superior VOC adsorption properties, thermal stability to 750°C and hydrophobicity and negligible influences of PNP on PCHs make spent PNP-containing organobentonites ideal starting materials for synthesis of PCHs and especially attractive adsorbents for VOC sorption control.

Clay minerals appear to change significantly under the influence of pasture development on poldered sediments in the Baie d'Authie area (Somme, France). Cores 40–90 cm deep from recent salt marsh sediments and poldered sediments developing grass pastures since 1737, 1575 and 1158 indicate that the natural mineral suite of kaolinite, mica, illite, and two disordered mixed-layered illite-smectite (I-S) phases common to the sedimentary input changes gradually but significantly in the materials. In the oldest, best-developed profile, there is a dominance of a disordered, illitic I-S in the humic upper part of the profile and a more abundant, more smectitic I-S mineral below. It appears that grass-derived humic materials tend to stabilize closed (collapsed) or illitic behavior in I-S clays. The natural evolution of the sediment (lower part of the profile) is towards a smectitic clay assemblage. Destruction of organic matter of the smectitic I-S minerals by oxidation indicates that this material can significantly modify the physical behavior of the clays keeping the structure open to polar molecules.

A geological, mineralogical, and geochemical characterization of the Tamame de Sayago (Zamora, Spain) deposit was carried out with the aim of knowing the conditions that facilitated the genesis in the same deposit of kaolinite and smectites. The alteration processes affecting a Variscan granite were deduced throughout the study of a very wide group of representative samples by X-ray diffraction (XRD), scanning electron microscopy (SEM), chemical analyses of major, minor, and trace elements, as well as δ18O, δ34S stable isotope and K/Ar dating analyses. In addition, 2D and 2.5D graphs of the kaolinite and smectite isoconcentrations were obtained from core data. According to the color and texture, two different clayey rock types were identified and named as homogeneous alteration zones (ZAHO) and heterogeneous alteration zones (ZAHE). The ZAHO are regoliths in which the granite texture is preserved, and the feldspars are almost completely kaolinized. In the ZAHE, the original texture of the granitic rock is lost, and the main clay mineral is smectite. The mineralogical composition is similar, with kaolinite, smectite, mica, quartz, scarce feldspar, and occasionally natroalunite and APS (aluminum-phosphate-sulphate); however, the mineral concentration varies considerably because ZAHO are rich in kaolin areas whereas ZAHE are bentonitic areas. Both rock types contain numerous veins and nodules. The weathering of the Paleozoic granite alongside the absence of sedimentation during the Mesozoic led to the formation of kaolinite that is preserved in ZAHO materials. Nonetheless, during the Cretaceous–Tertiary transit, the conditions of tectonic stability varied. Late Variscan faults reactivated which allowed the percolation of Mg- and Ca-rich hydrothermal fluids through the already kaolinized granite, increasing the alteration of the primary silicates and leading to the formation of smectites in ZAHE materials. The amount of smectites is greater closer to the faults. The stable isotopes indicate the meteoric nature of the low-temperature hydrothermal fluids. The K/Ar data obtained from the natroalunite of veins indicate that those hydrothermal fluids circulated in different pulses from 66.4 ± 1.7 to 58.8 ± 1.5 Ma, as a minimum. Those ages are coincident with the first formation stages of the Duero Basin.

The rheological characteristics of purified bentonite suspensions as a function of exchangeable cation $({\text{Ca}}^{2+},{\text{NH}}_4^{+},{\text{Li}}^{+})$$({\rm{C}}{{\rm{a}}^{2 + }},{\rm{NH}}_4^ + ,\;{\rm{L}}{{\rm{i}}^ + })$ are studied at three different clay concentrations (40 gL−1, 60 gL−1, 80 gL−1). A Herschel-Bulkley model is used to determine rheological parameters such as yield value, consistency and fluidification index. The flow curves are typical for shear thinning fluids but differ on two points; presence of yield stress and/or thixotropy. The Li suspensions are not yield stress fluid, and the thixotropy is weakly expressed only for the 80 gL−1 suspension. On the contrary, Ca-clay suspension flow curves always present yield stress and a large thixotropic area. The NH4-clay suspensions exhibit an intermediate behavior as there is no thixotropy, but a yield stress appears for the most concentrated suspension. These differences in macroscopic mechanical properties are discussed with reference to the suggested microscopic clay organization in suspension.

The Japanese empire’s occupation of China during the Second World War left a complex and bitter legacy in postwar Chinese society. This article examines the occupation and its legacies at the grassroots, taking university students in Nanjing as a case study in occupation history and ‘bottom-up’ wartime commemoration. These young people, who studied at National Central University (NCU) under the Japanese-backed Reorganized National Government of Wang Jingwei, organized three protest movements between 1940 and 1945, defying puppet authorities, Japanese forces, and, after the war, the returning Chongqing Nationalist government, as they campaigned against corruption, opium sales, and discriminatory treatment over their status as ‘bogus students’ who supposedly received Japanese ‘enslavement education’ from a collaborationist regime. In the 1980s, after decades of marginalization under the People’s Republic of China, these former protestors began holding reunions, documenting their experiences, and campaigning for recognition from Nanjing University, which eventually recognized them as alumni. Drawing primarily on privately printed alumni memoirs and commemorative volumes, this article positions the protests in the history of youth activism in Nanjing. That NCU students were able to rehabilitate themselves was due to their own organizational prowess and a sympathetic reception from the leadership of a cash-strapped Nanjing University, though the interests of fellow alumnus Jiang Zemin and the Communist Party-state still set the parameters of historical memory. In this, the example of the Nanjing students complicates the top-down role of the state, as described in much previous scholarship on Chinese wartime commemoration, in producing politically motivated nationalist narratives of wartime history.

Due to swelling, smectite minerals are capable of intercalating many organic molecules in their interlayer space. Tetracycline (TC) is a group of antibiotics used extensively in human and veterinary medicine. The great aqueous solubility and long environmental half life of TC mean that the study of interactions between swelling clay minerals and TC are of great importance in TC transport and retention in subsurface soils. In the present study, the intercalation of TC molecules at different levels into smectites was investigated using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The shift of the FTIR bands of amide I and II in comparison to crystalline TC suggested a strong interaction between the amide groups and the clay surfaces. The band at 1455 cm−1 remained the same after TC intercalation into SAz-1, SWy-2, and SYn-1, suggesting that complexation was not a dominant mechanism of TC uptake by these minerals. With cation exchange as the major mechanism of TC intercalation into these minerals, simultaneous removal of H+ from solution protonated the TC molecules and provided a positive charge to interact with negatively charged mineral surfaces even in neutral to slightly alkaline conditions. The increase in interlayer distance after intercalation by TC, as revealed by XRD, suggested a tilted orientation of the intercalated TC molecules in both twisted conformation in acidic condition and extended conformation in alkaline condition.

The development of nanoparticles incorporating Gd3+ has attracted interest in the field of contrasting nanomedicine for magnetic resonance (MR) and computed tomography (CT). In order to achieve an effective contrasting performance, the amount and stability of Gd incorporated as well as particle-size control of the nanoparticles should be considered simultaneously. In the current study, Gd-diethylenetriaminepentaacetate(Gd-DTPA) was incorporated into layered double hydroxide (LDH) to meet the physicochemical properties required for MR-CT dual contrasting nanomedicine. Strategically, the particle size and nanometer incorporation of Gd-DTPA into LDH (GL-R hybrid) were controlled homogeneously using the reverse micelle method. X-ray diffraction showed that the hybrid obtained possessed a hydrotalcite phase. Dynamic light scattering and electron microscopic analyses showed that the hybrid had a controlled size of <200 nm with significant homogeneity. Fast Fourier-transform of transmission electron microscopy confirmed that the platelets of the GL-R hybrids were oriented randomly to form inter-particle space, enabling the Gd-DTPA moiety to be encapsulated stably. The encapsulation efficiency of Gd-DTPA was 20.8%, which was sufficiently high compared with other Gd-DTPA-incorporatedLDH. According to X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy, Gd-DTPA incorporated in the hybrid preserved its structure intact. Its potential as a dual modal contrast agent was demonstrated by measuring the concentration-dependent Hounsfield unit and magnetic resonance relaxivity, which were determined to be 230 at 2 mg/mL and 5.8 in the range ~0.2–1 mM-Gd, respectively.