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A series of bimetallic Fe/Cu mesostructured samples were synthesized via post-functionalization modification of MCM-41, without the ligand (MCM-41@Cu-Fe) and with ligand glutamine (MCM-41@Gln@Cu-Fe). A bimetallic mesostructured Fe-Cu/MCM-41 catalyst was also synthesized by the co-condensation method (Cu-Fe/MCM-41). The catalysts were characterized by nitrogen adsorption –desorption, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effect of the synthesis procedure on the catalyst's properties was investigated by N2 adsorption/desorption, XRD, and SEM. The catalysts were tested in the synthesis of 5-substituted 1H-tetrazoles. These catalysts are cost-effective for this reaction. Cu-Fe/MCM-41 sample exhibited better catalytic activity compared to other catalysts. [ABSTRACT FROM AUTHOR]

Asphalt mixture has complex gradation and mesostructure. Accurate prediction of the relationship between gradation and mesostructure is of great significance for the establishment of mesostructure numerical simulation model and image-based gradation detection. In this paper, featurization, stepwise regression, econometric hypothesis test are utilized for establishing the predicting models. Firstly, asphalt mixtures with 64 kinds of gradation are scanned by Computed Tomography (CT) to obtain the mesostructure images; Then a series of mesostructure parameters of voids and aggregates are put forward. On this basis, the relationship model between gradation and mesostructure is established and verified by featurization and statistical modeling method. The results show that for predicting the passing percentage of the 4.75 mm sieve and the mean value of average distance between aggregate centroids for 9.5–4.75 mm aggregates, the prediction error of passing percentage is acceptable. It illustrates that the relationship model between gradation and mesostructure established by statistical method is effective, and it is significance for material design and testing under the condition of big data in the future.

Asphalt mixture has complex gradation and mesostructure. Accurate prediction of the relationship between gradation and mesostructure is of great significance for the establishment of mesostructure numerical simulation model and image-based gradation detection. In this paper, featurization, stepwise regression, econometric hypothesis test are utilized for establishing the predicting models. Firstly, asphalt mixtures with 64 kinds of gradation are scanned by Computed Tomography (CT) to obtain the mesostructure images; Then a series of mesostructure parameters of voids and aggregates are put forward. On this basis, the relationship model between gradation and mesostructure is established and verified by featurization and statistical modeling method. The results show that for predicting the passing percentage of the 4.75 mm sieve and the mean value of average distance between aggregate centroids for 9.5–4.75 mm aggregates, the prediction error of passing percentage is acceptable. It illustrates that the relationship model between gradation and mesostructure established by statistical method is effective, and it is significance for material design and testing under the condition of big data in the future. [ABSTRACT FROM AUTHOR]

David R. Maines was a key founder of the Society for the Study of Symbolic Interaction, and a champion of symbolic interactionist sociology. Maines fought against characterizations of symbolic interactionism as astructural and "subjectivist." He was adamant that symbolic interactionism offered vital perspectives on the study of social structure and organization, and that it was compatible with a variety of research methods. He played a vital role in developing narrative sociology and bringing narrative scholarship from communication studies to sociological audiences. In this retrospective on his life and career, I detail what Maines saw as the five central features of symbolic interactionism: (1) interpretation and meaning, (2) communication, (3) temporality and process, (4) agency, and (5) dialectical thinking. I then examine four interrelated themes of Maines' sociological contributions: (1) temporality, (2) debunking myths about interactionism, (3) mesostructure, and (4) narrative sociology. A video abstract is available at https://youtu.be/YodjvXbo51Q. [ABSTRACT FROM AUTHOR]

A convenient, one pot synthesis of heterocyclic nucleous acridine derivative compound achieved those are having very much attention in medicinal chemistry because of their extensive application in biology. The mixture of dimedone, substituted benzaldehyde, and aniline catalyzed by efficient In2O3-SiO2 heterogeneous reusable catalyst in ethanol to obtain the desired acridine derivatives with good yield. The hydrothermal method used to synthesize mesostructured In2O3-SiO2 catalytic material. This catalytic material were characterized by using X-ray diffraction spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, temperature-programmed desorption, and Brunauer–Emmett–Teller. Our synthetic strategy features high yield, simple work up procedure, nontoxic, clean, and easy recovery and reusability of the catalytic system. [ABSTRACT FROM AUTHOR]

A convenient, one pot synthesis of heterocyclic nucleous acridine derivative compound achieved those are having very much attention in medicinal chemistry because of their extensive application in biology. The mixture of dimedone, substituted benzaldehyde, and aniline catalyzed by efficient In2O3-SiO2 heterogeneous reusable catalyst in ethanol to obtain the desired acridine derivatives with good yield. The hydrothermal method used to synthesize mesostructured In2O3-SiO2 catalytic material. This catalytic material were characterized by using X-ray diffraction spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, temperature-programmed desorption, and Brunauer–Emmett–Teller. Our synthetic strategy features high yield, simple work up procedure, nontoxic, clean, and easy recovery and reusability of the catalytic system. [ABSTRACT FROM AUTHOR]

The complex and highly organized structural arrangement of some five billion cardiomyocytes directs the coordinated electrical activity and mechanical contraction of the human heart. The characteristic transmural change in cardiomyocyte orientation underlies base-to-apex shortening, circumferential shortening, and left ventricular torsion during contraction. Individual cardiomyocytes shorten ~15% and increase in diameter ~8%. Remarkably, however, the left ventricular wall thickens by up to 30-40%. To accommodate this, the myocardium must undergo significant structural rearrangement during contraction. At the mesoscale, collections of cardiomyocytes are organized into sheetlets, and sheetlet shear is the fundamental mechanism of rearrangement that produces wall thickening. Herein, we review the histological and physiological studies of myocardial mesostructure that have established the sheetlet shear model of wall thickening. Recent developments in tissue clearing techniques allow for imaging of whole hearts at the cellular scale, whereas magnetic resonance imaging (MRI) and computed tomography (CT) can image the myocardium at the mesoscale (100 mm to 1 mm) to resolve cardiomyocyte orientation and organization. Through histology, cardiac diffusion tensor imaging (DTI), and other modalities, mesostructural sheetlets have been confirmed in both animal and human hearts. Recent in vivo cardiac DTI methods have measured reorientation of sheetlets during the cardiac cycle. We also examine the role of pathological cardiac remodeling on sheetlet organization and reorientation, and the impact this has on ventricular function and dysfunction. We also review the unresolved mesostructural questions and challenges that may direct future work in the field. [ABSTRACT FROM AUTHOR]

To study the effects of the number of freezing–thawing cycles (F-T cycles), the dry density, and the average particle diameter on the mechanical properties of tailings, the calibration laws of the fine-scale parameters in the discrete particle element numerical simulation software PFC2D(Particle Flow Code) were first tested, and then pre-experiments were conducted in the form of orthogonal tests. Finally, according to the results of the pre-experiments and the analysis of the pre-experimental results by SPSS (Statistical Product Service Solutions) software, uniaxial tests were carried out for different numbers of freeze–thaw cycles, different dry densities, and different average particle sizes. The tailings specimens were subjected to uniaxial compression simulations. The results showed that (1) the uniaxial compressive strength of the tailings specimens decreased with each freeze–thaw cycle, and stabilized after seven freeze–thaw cycles. (2) With a greater number of freeze–thaw actions, the porosity of the tailings increased after freeze–thawing. The peak of porosity was much higher than that of the models with fewer than seven freeze–thaw actions. (3) The contact number of tailings specimens showed a significant decrease after the number of freeze–thaw cycles reached seven. However, the amount of exposure was not the main factor affecting the strength of tailings (4). As the number of freeze–thaws increased, the tailings model was more prone to stress concentration. Previously, PFC software has been applied to tailings simulation studies, and this study verifies the feasibility of this method. This research is able to offer a reference for studying the mechanical property changes of tailings in the cold highland area. [ABSTRACT FROM AUTHOR]

Two versions of powders of a charge of detonation nanodiamond doped with 0.96 and 0.73 wt % boron are obtained by explosion using a mixture of TNT with hexogen (TG) (50/50) or tetryl, respectively. Their morphology, texture, and mesostructure are investigated by scanning electron microscopy, small-angle neutron scattering, and low-temperature nitrogen adsorption. A significant effect of the explosion's precursor on the structure and morphology of the obtained carbon nanopowders is found. [ABSTRACT FROM AUTHOR]

Common structures in engineering such as slopes, roadbeds, ballasts, etc., are closely related to granular materials. They are usually subjected to long-term cyclic loads. This study mainly focused on the mechanical behaviors of randomly arranged granular materials before they reach a stable state under different cyclic loads. The variation of the maximum axial strain and the influence of CSR (cyclic stress ratio) were analyzed. The energy consumed in each cycle under constant confining stress loading condition is significantly greater than that of the fixed wall loading condition. The internal deformation evolution of granular materials is studied in detail. The deformation mode of granular material under cyclic loading at different positions inside the material is different according to the strain variation. In addition, the strain, force chain structure and contact force magnitude are combined to explore their effects on local deformation of granular materials under cyclic loading. From the perspective of the deformation form, the material sample can be divided into several regions, and the ability to adjust particle positions determines the deformation mode of different regions. The changes of local strain with the cyclic loading also reflect the contribution of particle displacements to the evolution of microstructure. This research will provide insights into the understanding of granular materials behaviors under cyclic loading. [ABSTRACT FROM AUTHOR]

The properties of sol-gel synthesis of borosilicate sols, wet gels and xerogels, as well as thin nanosized films were studied. Physicochemical processes and phenomena accompanying sol-gel synthesis of borosilicate sols, gels, xerogels, and thin spin-on glass films were analyzed on the basis of reference data and our long-term experience. Particularly, the sol-gel synthesis of borosilicate materials with high boron concentration were described in detail. The morphology, mesostructures and chemical composition of sol-gel derived borosilicate composites with a high boron content (from 30 to 48 wt %, based on B2O3) were studied using a number of complementary research methods (optical, scanning and transmission microscopy, small-angle X-ray scattering, and FTIR spectroscopy). The effect of sol composition (concentrations of Si(OEt)4 and H3BO3), ofthe addition of polyols (primarily glycerol), of the conditions for synthesis and of aging of target materials on their composition were studied, as well as the morphology and mesostructures of the composites. [ABSTRACT FROM AUTHOR]

Realization of high energy density Li-ion anodes is a significant challenge due to the volume changes generally exhibited by such systems during charge and discharge. Here, three-dimensional inverse opal (3D-IO) mesostructured Ni@TiO 2 @RGO electrodes were fabricated by templating nickel electrodeposition with self-assembled, three dimensionally ordered polystyrene (PS) opals, followed by atomic layer deposition (ALD) of TiO 2 and spray coating of reduced graphene oxide (RGO). The electrode delivers initial discharge and charge volumetric capacities of 2082 mAh cm-3 and 1873 mAh cm-3 at 0.5 C, respectively. The composite electrode exhibits volumetric discharge and charge capacities of 1508 mAh cm-3 and 1504 mAh cm-3 at 0.5 C after 200 cycles and good rate capacity up to at least 10 C. The almost unbroken 3D-IO mesostructure after 200 lithiation and delithiation cycles demonstrates the excellent structural stability of the 3D-IO electrode design concept. The enhanced volumetric capacity and structural stability originate from high active materials loading, the short and efficient ion and electron pathways, and the composite structure provided by the nickel electrodeposition, ALD, and RGO spray coating electrode preparation process, as well as that both TiO 2 and RGO participate in lithium storage. [ABSTRACT FROM AUTHOR]

Cationic cylindrical polymer brushes based on polybutadiene-block-poly(2-vinylpyridine) were applied as structure-directing agent for mesostructuring Fe2O3 nanoparticles into nanotubes. After temperature-controlled template removal, the obtained non-woven catalysts were tested for the photodegradation of ciprofloxacin under terrestrial solar radiation. At a slightly basic pH value, as typically encountered in clinical wastewaters, the mesostructured Fe2O3 shows a 4.5 times faster degradation of ciprofloxacin than commercial Aeroxide® TiO2 P25. Even wide-bandgap ZnO, mesostructured in the same way, is 1.6 times slower. Moreover, the non-woven-like structure of the catalyst allows for easy recovery of the catalyst and operation in a continuous flow reactor. [ABSTRACT FROM AUTHOR]

Curcumin is a natural active principle with antioxidant, antibacterial and anti-inflammatory properties. Its use is limited by a low water solubility and fast degradation rate, which hinder its bioavailability. To overcome this problem, curcumin can be delivered through a carrier, which protects the drug molecule and enhances its pharmacological effects. The present work proposes a simple one-pot sol–gel synthesis to obtain a hybrid carrier for curcumin delivery. The hybrid consists of a mesostructured matrix of amorphous silica, which stabilizes the carrier, and hexadecyltrimethylammonium (CTA), a surfactant where curcumin is dissolved to increase its water solubility. The carrier was characterized in terms of morphology (FESEM), physicochemical properties (XRD, FTIR, UV spectroscopy) and release capability in pseudo-physiological solutions. Results show that curcumin molecules were entrapped, for the first time, in a silica-surfactant mesostructured hybrid carrier. The hybrid carrier successfully released curcumin in artificial sweat and in a phosphate buffer saline solution, so confirming its efficacy in increasing curcumin water solubility. The proposed drug release mechanism relies on the degradation of the carrier, which involves the concurrent release of silicon. This suggests strong potentialities for topical administration applications, since curcumin is effective against many dermal diseases while silicon is beneficial to the skin. Highlights: A novel mesostructured curcumin-containing hybrid carrier was successfully synthesized. The hybrid enhances curcumin solubility in pseudo-physiological conditions (e.g., artificial sweat). Curcumin release is governed by a degradation process of the silica matrix. Degradation of the hybrid induces the simultaneous release of curcumin, silicates, and surfactant. [ABSTRACT FROM AUTHOR]

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Recently, perovskite solar cells (PSCs) have attracted more attention. TiO2 as the most common electron transfer material in PSCs has been improved by a serious of methods. In this study, a simple method was used to improve the traditional compact TiO2 properties by doping with Sn4+. It demonstrated that the conductivity of the TiO2 film could be well improved and the band-gap shifted from 3.65 to 3.55 eV with the introduction of Sn ions. The Sn–O–Ti bond was observed in the Sn:TiO2 film according to the results of XPS. The mesostructured PSCs based on Sn:TiO2 exhibited negligible J-V hysteresis behavior, and the Jsc of the device increased distinctly. The power conversion efficiency (PCE) of the Sn:TiO2 device was improved from 14.86 to 17.11%, compared with the reference device. [ABSTRACT FROM AUTHOR]

• New mesostructured Silica hybrid materials have been synthesized via the sol-gel process and their structures were studied by FT-IR, 29Si and 13C NMR. • The scanning electron microscopy study shows that the prepared materials are formed of spherical nanoparticles. • Pore sizes analysis reveals the mesoporous nature of the materials. • Both silica-based gels display potent antimicrobial activities and offer potential mean of fighting microbes. • Silica hybrid gels are cytocompatible with normal human skin cells, and are therefore promising pharmacophores for therapeutic use. New transparent and monolithic silica hybrid gels with high antibacterial and antifungal activities have been synthesized by soft chemistry. The synthesis has been carried out via sol-gel process, by grafting difunctional-1,3,4-thiadiazole components into a silica network, using 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS) as a silicon source. The obtained xerogels were characterized using 13C and 29Si CP MAS NMR, FTIR spectroscopy and SEM. The results of this study reveal that the 1,3,4-thiadiazole nuclei have been chemically cross-linked to the silica backbone structure leading to hybrid materials. The pore sizes and specific surface areas were evaluated using N 2 adsorption/desorption isotherms. The specific surface area found to be ranged from 302 to 365 m2.g−1. Small particle size with a narrow pore size distribution and an average diameter between 2.5 and 3.5 nm characteristic of a mesoporous structure of xerogels was observed. Scanning electron microscopy showed that the xerogels were formed of spherical nanoparticles whose diameter is of around ten nanometers. Gels antimicrobial activity has been evaluated against Gram-negative and Gram-positive bacteria and the fungus Candida albicans. This study demonstrated significant biosafety of the as-synthesized products and cytocompatibility with normal human skin cells was observed, supporting their potential use as promising candidates for therapeutic application. [ABSTRACT FROM AUTHOR]

In this paper, the sliding structure morphology, mechanical and tribological behavior of thermoplastic polyurethanes (TPU) under different conditions were studied. The coefficient of friction of TPU stabilizes rapidly at relatively low values and the wear rate increased. High load conditions significantly improved TPU's coefficient of friction and wear rate. However, a high sliding speed was helpful to form a transfer flimsy. Therefore, the coefficient of friction and wear rate of TPU were reduced at higher sliding speeds. The morphology of the wear surface of TPU indicated that the main wear process was viscous wear and wears fatigue under dry and sliding conditions. Using open-source 3D printer is common to use a series of fillers mode and density to reduce time and consumption. Involving the same FDM technique, it is an important to evaluate its strength with this technology. Herein, the effects of more adjustable variables, such as frequencies, infill patterns, density and loads, has been evaluated in detail. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanoparticles were mesostructured by polybutadiene- block -poly(2-vinylpyridine) cylindrical polymer brushes as a template. Loading the positively charged vinylpyridine block with ZnO nanoparticles produced hybrid rods with high aspect ratio. Mesostructured ZnO nanotubes obtained by pyrolytic template removal show high activity in the photocatalytic degradation of ciprofloxacin using a continuous flow reactor and irradiation with terrestrial solar spectrum. In comparison with Degussa P25, a titanium dioxide photocatalyst, the degradation is 2.9 times faster. Due to its non-woven microstructure, the photocatalyst, moreover, can be easily separated from fluid reaction media by filtration. [ABSTRACT FROM AUTHOR]

A complex moiety containing VO(IV) was anchored covalently into organic-modified Si-MCM-41 to prepare a new catalyst. The prepared materials were characterized using various techniques. Several types of aromatic and aliphatic sulfides were successfully oxidized to the corresponding sulfoxides in good to excellent yields using H2O2 in the presence of a catalytic amount of the catalyst under solvent-free conditions. The results showed that the OH groups of the various compounds such as 2,2-(phenylthio)ethanol and 2-(methylthio)ethanol remained intact under similar conditions. Meanwhile the catalyst was stable in the reaction system, and could be reused at least four times without significant loss of its activity and chemoselectivity. [ABSTRACT FROM AUTHOR]

Acetalization of glycerol with acetone was examined using M-AlPO 4 / x AlPO 4 ( x = Zn, Cu, Ni, or Co) solid acid catalysts with enlarged surface areas. The relationship between the structural properties and the catalytic performances was investigated. The synthesized catalysts were systematically analyzed using various techniques, namely, XRD, SEM/TEM, EDX, BET surface area, pore size distribution, FTIR, UV–vis spectrophotometry and NH 3 -TPD. The XRD results suggested the formation of mesostructured amorphous materials. The SEM/TEM results showed that these materials had an ordered structure. All of the materials exhibited uniform pore size and high specific surface area. The strength of the acid sites of the M-AlPO 4 / x AlPO 4 ( x = Zn, Cu, Ni, or Co) solid acid catalysts was studied by NH 3 -TPD. UV–vis spectrophotometry was used as a novel method to measure the exact amount of acid sites of the M-AlPO 4 / x AlPO 4 ( x = Zn, Cu, Ni, or Co) solid acid catalysts. The resulting materials were found to exhibit excellent catalytic activity for the acetalization of glycerol with acetone. The reaction with M-NiAlPO 4 showed the highest yield (75.44%) and the best selectivity (75.12%). [ABSTRACT FROM AUTHOR]

Abstract: Among other potential applications, mesoporous titania with high surface area and crystalline framework is attractive in photocatalytic hydrogen production. The mesoporous structure with pore walls formed by nanocrystals of anatase would provide a shorter distance of the electron–hole pairs to reach the photocatalyst surface and a higher surface area to deposit modifiers of its photocatalytic activity. In this work, we have successfully applied a hard-templating pathway to obtain ordered mesoporous titania (m-TiO2) with high surface area and anatase as main crystalline phase. Subsequently, various amounts of metallic Pt have been deposited using different impregnation methods. All reactions performed exhibit, at short times, a rapid increase in the hydrogen production rate until a point in which a nearly constant value is achieved. The material prepared by the “citrate method”, based on reduction and encapsulation with sodium citrate of Pt nanoparticles before the photocatalytic reaction, leads to the highest hydrogen production rates with the shortest time to reach the change on the trend of the activity curve. The reason of this result is that citrate method provides very good dispersion and, specially, because the Pt nanoparticles are deposited and reduced preferentially within the pores of m-TiO2, leading to stronger interactions than the other two explored dispersion routes (wetness impregnation and photodeposition). Thus, despite introducing less than half of the theoretical amount of Pt, citrate method produces close to twice the amount of hydrogen obtained by the other dispersion routes. This production capacity is even higher when the amount of Pt loaded is increased, with the optimal concentration being determined as 2% (w/w). [Copyright &y& Elsevier]

Abstract: An investigation of the porosity of a thin mesoporous titania film was performed using both ellipsoporosimetry and thermoporometry. These films are prepared using the sol–gel process with a block copolymer PEO–PPO–PEO (P123) and a thermal treatment at 350°C. The film is constituted by a single layer with oblate pores whose small and high diameters are respectively equal to 5 and 7nm. The porous volume is 31% or 36% depending of the method used. The porous titania film has also been used as a template for the growth of silver nanoparticles. Impregnation of the porous film in a silver salt solution is followed by a reduction step with sodium borohydride. Ellipsoporosimetry is then the only way to study the porosity, using a two-layer model. The first thin layer (35nm) is slightly porous and contains a lot of large silver nanoparticles. The second under layer is thicker (180nm) and has a porosity similar to the empty layer one. [ABSTRACT FROM AUTHOR]

A new type of mesostructured ceria material was synthesized via template-assisted precipitation method and tested for the oxidative dehydrogenation (ODH) of ethylbenzene to styrene by molecular oxygen. The effect of calcination temperature on the catalytic performances of the ceria catalysts has been investigated. Among the catalysts tested, the CeO2-450 sample derived by calcination at 450 °C exhibited the highest ethylbenzene conversion (34%) and styrene selectivity (87%). Comparing the reaction rates for ODH of ethylbenzene (ca. 6.1 mmol ST g h−1 at 450 °C) with the highly active nanostructured carbon-based catalysts in the current literature confirmed the very high activity of these new materials. The superior catalytic performance of the CeO2-450 sample can be attributed to its high specific surface area and enhanced redox properties as revealed by H2-TPR measurements. [ABSTRACT FROM AUTHOR]

Abstract: Mesostructured silica nanotubes have been synthesized in a system of carbon nanotubes/cetyltrimethylammonium bromide/tetraethyl orthosilicate/NH3·H2O through one-pot hydrothermal route. The obtained sample was characterized with X-ray diffraction, nitrogen sorption, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray techniques. These results indicate mesostructured silica nanotubes exhibit small tube diameters (10–40nm), uniform mesopores (2.5nm), and a huge pore volume (1.7cm3/g). [Copyright &y& Elsevier]

Abstract: A mesostructured cobalt oxide microsensor was fabricated using a template replication method under different hydrothermal treatments, and attempts were made to enhance the response of this gas sensor. To evaluate the sensing performance, the sensing materials were deposited via the dielectrophoresis (DEP) process, on micro-hot-plate platforms with interdigitated electrodes. The resistance changed when the carbon monoxide target gas was injected at the optimum temperature. The mesostructured cobalt oxide material with high hydrothermal treatment revealed the well-ordered domains, whereas with low hydrothermal treatment it did not contain ordered domains. Moreover, the cobalt oxide high hydrothermal material had 1.5 times the response to 70ppm carbon monoxide as the low hydrothermal treatment sample. The unobstructed interconnectivity promotes gas diffusion and increases the active surface areas. [Copyright &y& Elsevier]

Abstract: Flexible bi-continuous mesostructured polymer/inorganic composite membranes have been synthesized by undertaking co-assemblies of surfactants and inorganic sol–gel processes inside pores of a preformed porous polymer membrane such as PP porous membrane Celgard® 2400. The pores are interconnected across the membranes, therefore the continuity of the inorganic mesopores across the membranes is guaranteed in principle. The solvent ethanol used for silica sol is conducive to the synthesis of inorganic materials such as silica within the pores although the PP membrane is hydrophobic. The composite membranes show new properties such as transparency, flexibility, uniform nanosized pores and enhanced permeability. [Copyright &y& Elsevier]

Mesoporous sulfated Al2O3–ZrO2 (MSAZ) catalysts with large surface areas and pore volumes after calcination at high temperature (650 °C) and with higher Al2O3 content than 20wt% were successfully prepared from a template of block copolymer (P84). The MSAZ catalysts were characterized by X-ray diffraction (XRD), N2 adsorption, transmission electron microscopy (TEM), 27Al magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (TG–DTG), temperature-programmed desorption of ammonia (NH3-TPD) and infrared spectra (IR) of adsorbed pyridine. It is shown that the resulting mesostructured sulfated Al2O3–ZrO2 samples have a well-developed textural mesoporosity. The number of acid sites present on MSAZ catalysts is higher than that on conventional sulfated zirconia, and the former catalysts are more active than the latter one for various acid-catalyzed reactions. [ABSTRACT FROM AUTHOR]

Mesoporous sulfated Al2O3–ZrO2 (MSAZ) catalysts with large surface areas and pore volumes after calcination at high temperature (650 °C) and with higher Al2O3 content than 20wt% were successfully prepared from a template of block copolymer (P84). The MSAZ catalysts were characterized by X-ray diffraction (XRD), N2 adsorption, transmission electron microscopy (TEM), 27Al magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (TG–DTG), temperature-programmed desorption of ammonia (NH3-TPD) and infrared spectra (IR) of adsorbed pyridine. It is shown that the resulting mesostructured sulfated Al2O3–ZrO2 samples have a well-developed textural mesoporosity. The number of acid sites present on MSAZ catalysts is higher than that on conventional sulfated zirconia, and the former catalysts are more active than the latter one for various acid-catalyzed reactions. [ABSTRACT FROM AUTHOR]

Abstract: Novel lamellar mesostructured hydroxyapatites have firstly been synthesized by template-assisted technique. The mild and nontoxic surfactant, phosphoric acid monododecyl ester (MAP), is used to act as a structure-directing template. The structure of sample was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Scanning electron microscope and Transmission electron microscopy. The results indicate that the obtained sample is a well-organized lamellar mesostructured hydroxyapatite with a uniform layer spacing of 3.64 nm. [Copyright &y& Elsevier]

Abstract: The structure of the preformed LC mesophase of water:transition metal salt ([M(H2O)6]X2):acid (HX):oligo(ethylene oxide) (or Pluronics):tetramethylorthosilicate (TMOS) mixture during hydrolysis and partial polymerization of the silica source is maintained upon further polymerization and condensation of the silica species in the solid state. The liquid mixture in early stage of the silica polymerization could be casted or dip coated to a surface of a glass or silicon wafer to produce mesostructured silica monoliths and films, respectively. The silica species and ions (metal ions and anions) influence the structure of the LC mesophases (as a result, the structure of silica) and the hydrophilic and hydrophobic balance in the reaction media. The silica structure can be changed from hexagonal to cubic by increasing, for example, the nitrate salt concentration in the nitrate salt systems. A similar transformation takes place in the presence of very low perchlorate salt concentration. The salt concentration in the mesostructured silica can be increased up to 1.1/1.0 salt/SiO2 w/w ratio, in mesostructured silica materials by maintaining its lamella structure in P123 and cubic in the C n EO m systems. However, the materials obtained from the P123 systems undergo transformation from lamella to 2D hexagonal upon calcinations. The method developed in this work can be used to modify the internal surface of the pores with various transition metal ions and metal oxides that may find application in catalysis. [Copyright &y& Elsevier]

Mesostructured aluminosilicate nanoparticles with wormhole-like framework structure were synthesized via sol–gel route at low temperature using cationic cetyltrimethylammonium bromide (CTAB) as template. Similar to hexagonal AlMCM-41, the mesoporous nanoparticles had high surface area and uniform mesopores. It is more desirable that acid sites were generated directly by calcining the as-synthesized nanoparticles, making a subsequent ion-exchange and calcination treatment superfluous. The acid strength of acid sites on the present mesoporous nanoparticles was close to that on AlMCM-41 material, but less strong than that of on microporous HZSM-5 crystals. Although highly acidic HZSM-5 was active for cumene cracking, the nanoparticles and AlMCM-41 were much more catalytically active in bulky 1,3,5-triisopropylbenzene cracking due to the facilitation of diffusion of reactant/product molecules. More interestingly, the mesoporous Al substituted nanoparticles still exhibited excellent activities in 1,3,5-triisopropylbenzene transformation after severe treatment by pure steam at 800 °C for 2 h. In contrast, well-ordered AlMCM-41 totally lost its activity after the same treatment. [ABSTRACT FROM AUTHOR]

A mesostructured sulfated tin oxide with large surface area (172 m2/g) has been successfully prepared using a block copolymer as structure-directing agent, which is extensively characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption, and Thermogravimetric analysis (TG) techniques. The results indicate that the mesostructured sulfated tin oxide was tetragonal crystalline, and catalytic tests show that the mesostructured sulfated tin oxide is much more active than conventional one for esterification and Friedel–Crafts acylation. [ABSTRACT FROM AUTHOR]

Abstract: The stereoselective hydrogenation of phenyl acetylene and 1-phenyl-1-hexyne at 298K and atmospheric pressure of H2 over Pd catalysts supported on mesostructured silica was studied. The catalysts were prepared by the impregnation of HMS and MSU-X silicas with 3-D wormhole framework structures and MCM-41 silica with a 1-D hexagonal framework using a toluene solution of Pd(acac)2 to obtain a metal content close to 1wt.%. All the supports were characterised by nitrogen adsorption–desorption isotherms at 77K and XRD. The catalysts were characterized by H2 chemisorption and TEM measurements. The reactions were found to be zero order with respect to the phenyl acetylene and 1-phenyl-1-hexyne concentration. Each catalyst presented a different catalytic performance. The 1%Pd/HMS catalyst was the most active in comparison with the 1%Pd/MSU-X and 1%Pd/MCM-41 catalysts. This superior performance in the case of the HMS support was attributed to the presence of interconnected framework channels and textural mesoporosity that can increase the accessibility of the Pd centers to a greater extent than the more monolithic MSU-X and MCM-41 supports. All catalysts displayed high selectivity to styrene and cis-1-phenyl-1-hexene compounds. [Copyright &y& Elsevier]

Thermally stable mesostructured sulfated zirconia (MSZ) with a high surface area has been successfully prepared by a novel one-step synthetic method involving the alcohothermal processing of zirconium nitrate in the presence of ammonium sulfate. The MSZ samples were characterized using X-ray diffraction (XRD), N2 adsorption measurements, thermal analysis (TG/DTA) and transmission electron microscopies (TEM). It is shown that the resulting mesostructured sulfated zirconia samples are tetragonal crystalline, which have a high specific surface area and a well-developed textural mesoporosity with narrow pore size distribution. Catalytic testing showed that the present mesostructured sulfated zirconia was much more active than conventional sulfated zirconia forn-butane isomerization. [ABSTRACT FROM AUTHOR]

Al-promoted mesostructured sulfated zirconia (Al-MSZ-5) has been successfully synthesized from the template of triblock polymer surfactant (P123) in aqueous solution. Mesostructured Al-MSZ-5 shows high thermal stability, and it can preserve its characteristic mesostructures until calcination at 650 °C. In contrast, the mesostructure of mesoporous sulfated zirconia (MSZ-5) will be destroyed during calcination at 600 °C. Catalytic data for n-butane isomerization show that the Al-MSZ-5 exhibits higher catalytic activity and better stability than both MSZ-5 and conventional Al-promoted sulfated zirconia (Al-SZ). The Al-MSZ-5 sample was characterized by XRD, bright-field and dark-field TEM images, N2 adsorption isotherms, NMR, TG–DTA, IR, and numerous other techniques. The results suggest that Al-MSZ-5 has worm-like mesopores, and that the mesostructured walls contain tetragonal crystalline ZrO2. Such unique structural features might be responsible for the observed large surface area, high catalytic activity for n-butane isomerization, and high thermal stability of mesostructured Al-MSZ-5. [Copyright &y& Elsevier]

A facile two-step sol–gel method has been developed for the preparation of mesostructured aluminosilicate nano-particles (Si/Al = 7.5) with wormhole-like but uniform pore structures and highly catalytic activities towards bulky hydrocarbon cracking. It is desirable that, as this synthesis takes place in the absence of alkali cations, the mesoporous nano-particulate material is directly obtained in the acid form, making a subsequent ion-exchange and calcination treatment superfluous. [ABSTRACT FROM AUTHOR]

The catalytically important vanadyl hydrogen phosphate hemihydrate, VOHPO4 · 0.5H2O phase with strong interlayer bonding has been exfoliated for the first time in DMF-water mixture and the exfoliated hemihydrate phase has been reorganized into a novel mesostructured lamellar VPO phase having the same V–P–O connectivity as in VOHPO4 · 0.5H2O, using octadecyl amine as the structure directing template. [Copyright &y& Elsevier]

A mesostructured γ-alumina with a lathlike framework morphology, denoted MSU-γ, has been prepared according to previously described methods through the reassembly and crystallization of a mesostructured alumina precursor with initially amorphous framework walls and used as a support for the catalytic hydrodesulfurization (HDS) of dibenzothiophene (DBT). The alumina support was loaded with molybdenum and cobalt ions via incipient wetness impregnation methods and then converted to the active sulfide form by reaction with H2S. HDS reactions of DBT were carried out at 400 °C and 400 psi to achieve a DBT conversion of 69–77% and a biphenyl (BP) product selectivity of 60–64% after a reaction time of 3 h, indicating that most of the DBT could undergo desulfurization while limiting excessive hydrogen consumption through aromatic hydrogenation. Although the dispersion of the active Mo/Co sulfide phase supported on lathlike MSU-γ alumina remained very high after several hours on stream, the conversions most likely were limited by a loss of surface area and porosity under HDS conditions. [Copyright &y& Elsevier]

A mesostructured sulfated zirconia with a large surface area (189 m2/g) has been successfully prepared using a triblock copolymer as a structure-directing agent. The resulting material was characterized by XRD, TEM, nitrogen adsorption, FTIR and TG/DTA, which suggested that the mesostructured sulfated zirconia was tetragonal crystalline. Catalytic testing showed that the mesostructured sulfated zirconia was much more active than conventional sulfated zirconia for n-butane isomerization. [ABSTRACT FROM AUTHOR]

Mesostructured zirconia has been synthesized by using zirconium chloride and PEO nonionic ethoxylated sorbitan ester (Tween-20, -40, -60 or -80) as a zirconium source and structure-directing agent in an aqueous medium. To remove the occluded surfactants, UV/ozone treatment has been utilized instead of calcination due to thermal instability. This results from a special molecular structure of Tween surfactant. From XRD, SEM and TEM analyses, the materials treated with UV light and in-situ generated ozone has a wormhole structure and ill-defined or well-defined spherical particles. [ABSTRACT FROM AUTHOR]

Ordered mesostructured hexagonal, cubic and lamellar vanadium-phosphorus-oxide phases displaying improved thermal stability, desirable bulk compositions, and vanadium oxidation states (3.8–4.3) for the partial oxidation of lower alkanes were synthesized using cationic (alkyl trimethyl ammonium salts), anionic (alkyl sulfonates and phosphates) and primary alkylamines as structure-directing agents. It was found that hexagonal mesophases were favored at short carbon chain lengths (C12–C16), while cubic phases were favored for longer chains (C18). Structure-directing agents were removed by calcination or Soxhlet extraction in ethanol. When structure-directing agents were removed by extraction, phase transformations from hexagonal to cubic to lamellar structures were observed. The improved thermal stability of these mesophases was attributed to the acidic self-assembly conditions in the vicinity of the isoelectric point of V(V) oxocations. [Copyright &y& Elsevier]