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Changing the morphology is an excellent option for altering the textural parameters of SBA-15 materials. This study provides a guide on how the properties of mesoporous structures behave according to their morphology and their contribution to thermal stability. The objective of this work was to synthesize different morphologies (spherical, hexagonal prisms, rice-like grains, rods, and fibers) of SBA-15 materials and evaluate the existing textural changes. The materials were synthesized by varying the temperature of the synthesis gel from 25 °C to 55 °C, with stirring at 300 or 500 rpm. The results of X-ray diffraction, Fourier transform infrared spectroscopy, N2 adsorption and desorption, and scanning electron microscopy were evaluated. Thermal stability tests were also conducted in an inert atmosphere. The materials were successfully synthesized, and it was observed that they all exhibited different characteristics, such as their ordering, interplanar distance, mesoporous parameter, specific surface area, micropore and mesopore volumes, external mesoporous area, and wall thickness. They also presented different thermal stabilities. The rice grain morphology had the highest specific surface area (908.8 cm2/g) and the best thermal stability, while the rod morphology had the best pore diameter (7.7 nm) and microporous volume (0.078 cm3/g).

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Mordenite is a well-known zeolite widely used for industrial processes. However, its pore architecture can be inconvenient due to diffusional issues. A study of the synthesis parameters from an organic-free dense gel was carried out to control the crystal morphology, which resulted in finned mordenite zeolite particles. The obtained materials were characterized by XRD, FTIR, 29Si and 27Al MAS-NMR, elemental analysis, nitrogen physisorption, SEM, and TEM. We found that careful manipulation of the hydrothermal parameters directly affected the sizes and morphologies of the crystallites and particles, as well as the textural properties of the final products. Additionally, it was found that mordenite could exhibit a fin morphology with additional mesoporosity, which is a promising means to reduce the diffusional problems of one-dimensional-channel zeolites.

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Silicoaluminophosphate molecular sieves of SAPO-11 type (AEL structure) were synthesized by the hydrothermal method, from the residue of a fluorescent lamp as a source or Si, Al, and P in the presence of water and di-propyamine (DPA) as an organic template. To adjust the P2O5/SiO2 and Si/Al and ratios, specific amounts of silica, alumina, or alumina hydroxide and orthophosphoric acid were added to obtain a gel with molar chemical composition 1.0 Al2O3:1.0 P2O5:1.2 DPA:0.3 SiO2:120 H2O. The syntheses were carried out at a temperature of 473 K at crystallization times of 24, 48, and 72 h. The fluorescent lamp residue and the obtained samples were characterized by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, and BET surface area analysis using nitrogen adsorption isotherms. The presence of fluorapatite was detected as the main crystalline phase in the residue, jointly with considered amounts of silica, alumina, and phosphorus in oxide forms. The SAPO-11 prepared using aluminum hydroxide as Al source, P2O5/SiO2 molar ratio of 3.6 and Si/Al ratio of 0.14, at crystallization time of 72 h, achieves a yield of 75% with a surface area of 113 m2/g, showing that the residue from a fluorescent lamp is an alternative source for development of new materials based on Si, Al, and P.

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The mixture containing alloy and oxide with iron-based phases has shown interesting properties compared to the isolated species and the synergy between the phases has shown positive effect on dye adsorption. This paper describes the synthesis of Fe2SiO4-Fe7Co3-based nanocomposite dispersed in Santa Barbara Amorphous (SBA)-15 and its application in dye adsorption followed by magnetic separation. Thus, it was studied the variation of reduction temperature and amount of hydrogen used in synthesis and the effect of these parameters on the physicochemical properties of the iron and cobalt based oxide/alloy mixture, as well as the methylene blue adsorption capacity. The XRD and Mössbauer results, along with the temperature-programmed reduction (TPR) profiles, confirmed the formation of Fe2SiO4-Fe7Co3-based nanocomposites. Low-angle XRD, N2 isotherms, and TEM images show the formation of the SBA-15 based mesoporous support with a high surface area (640 m2/g). Adsorption tests confirmed that the material reduced at 700 °C using 2% of H2 presented the highest adsorption capacity (49 mg/g). The nanocomposites can be easily separated from the dispersion by applying an external magnetic field. The interaction between the dye and the nanocomposite occurs mainly by π-π interactions and the mixture of the Fe2SiO4 and Fe7Co3 leads to a synergistic effect, which favor the adsorption.

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The need for greener procedures is a fact to reduce residues, to decrease industrial costs, and to accomplish the environmental agreements. In an attempt to address this question, we propose the addition of a natural resource, Brazilian diatomite, to an MFI zeolite traditional synthesis. We have characterized the resulting product with different techniques, such as X-ray diffraction, microscopy, and gas sorption, and, afterwards, we evaluate the greenness of the process by the Green Star method. The results were promising: We obtained the desired topology in the form of small crystallites aggregated and a pore diameter of 0.8 nm. In conclusion, the product has the necessary characteristics for an adsorption or catalytic future tests and escalation to industrial production.

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The present work introduces new functional bionanocomposite materials based on layered montmorillonite and fibrous sepiolite clays and two biopolymers (carboxymethylcellulose polysaccharide and zein protein) to produce drug-loaded bionanocomposite films for antibiotic topical delivery. Neomycin, an antibiotic indicated for wound infections, was employed as the model drug in this study. The physical properties and the antimicrobial activity of these materials were evaluated as a function of the type of hybrid and the amount of zein protein incorporated in the bionanocomposite films. In addition, the interfacial and physicochemical properties of these new clay-drug hybrids have been studied through a combination of experimental and computational methodologies, where the computational studies confirm the intercalation of neomycin into the montmorillonite layers and the possible penetration of the drug in the tunnels of sepiolite, as pointed out by N2 adsorption and X-ray diffraction techniques. The antimicrobial activity of these bionanocomposite materials show that the films based on montmorillonite-neomycin display a more pronounced inhibitory effect of the bacterial growth than those prepared with the sepiolite-neomycin hybrid. Such effect can be related to the difficult release of neomycin adsorbed on sepiolite due to a strong interaction between both components.

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Zeolite synthesis is a wide area of study with increasing popularity. Several general reviews have already been published, but they did not summarize the study of imidazolium species in zeolite synthesis. Imidazolium derivatives are promising compounds in the search for new zeolites and can be used to help understand the structure-directing role. Nearly 50 different imidazolium cations have already been used, resulting in a variety of zeolitic types, but there are still many derivatives to be studied. In this context, the purpose of this short review is to help researchers starting in this area by summarizing the most important concepts related to imidazolium-based zeolite studies and by presenting a table of recent imidazolium derivatives that have been recently studied to facilitate filling in the knowledge gaps.

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Pillared clays (PILCs) are interesting materials mostly due to their high basal spacing and surface area, which make them suitable for adsorption and catalysis applications, for example. However, the production of these materials on industrial scale is dependent on research about what parameters influence the process. Thus, the objective of this work was to evaluate what parameters influence the pillaring procedure. For this, pillared clays were synthesized following three series of experiments. In the first series, the effect of the amount of water in a clay suspension was evaluated. The best results were obtained by using diluted suspensions (1 g of clay to 100 mL of water). In the second series, several pillaring methods were tested. In the third series, the amount of pillared clay was raised to 50 g. Fifty grams of pillared clay can be obtained using the pillaring agent synthesized at 60 °C with further aging for 24 h, and this material exhibited high basal spacing (17.6 Å) and surface area (233 m²/g). These values are comparable with the traditional pillaring method using only 3 g of clay.

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This work describes the synthesis and characterization of pillared clays using a new pillaring method: the reuse of the pillaring solution. First, an Al pillared clay (PILC) was synthesized, and after filtration, the pillaring agent was stored and reused for an additional three pillaring procedures (P1, P2, and P3). The filtered pillaring solution was stored for one year and then reused for one additional pillaring procedure (P4). The samples were analyzed using XRD, N2 physisorption measurements and chemical analysis (EDX). All of the samples exhibited basal spacings larger than 17 Å and BET surface areas greater than 160 m²/g. After the P4 pillaring, the pillaring agent was precipitated with a Na2SO4 solution, and the resulting solid was analyzed using XRD and SEM. The results indicated that even after a total of five pillaring procedures, Al13 ions were still present in solution. Therefore, it is possible to reuse the pillaring solution four times and to even store the solution for one year, which is important from an industrial perspective.

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Olanzapine (OLZ) is a drug that is used in the treatment of schizophrenia and other psychoses, and it belongs to the thienobenzodiazepine class. The OLZ molecule has low solubility decreasing bioavailability, but has high permeability in membrane biological being classified as a Class II drug substance according to the Biopharmaceutics Classification System. It was reported many side effects of administering OLZ orally. So, in order to increase the bioavailability of drug and possibly reducing some of side effects, this paper proposes a new material able to controllably release the drug in the body. To control the dissolution rate, this work proposes a system that incorporates the drug into montmorillonite (MMT) dispersed in a mixture of alginate (ALG) and xanthan gum (XG) biopolymers. The proposed hybrids and bionanocomposites were characterized by several physicochemical techniques, including XRD, IR-ATR, TG DTA, SEM-EDS and HPLC. The characterization data confirmed the intercalation of the OLZ into the MMT by the ion exchange process, as well as the interaction of the MMT-OLZ with the biopolymers. The release test, conducted under various pH conditions, showed that the proposed system exhibited a more controlled drug release than commercial tablets, indicating that the ALG-XG/MMT-OLZ bionanocomposite can act as a controlled release system for OLZ.

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Both stability and catalytic activity of two commercial immobilized lipases were investigated in the presence of different organic solvents in ultrasound-assisted system. In a general way, for Novozym 435, the use of ethanol as solvent led to a loss of activity of 35% after 10 h of contact. The use of iso-octane conducted to a gradual increase in lipase activity in relation to the contact time, reaching a maximum value of relative activity of 126%. For Lipozyme RM IM, after 5 h of exposure, the enzyme presented no residual activity when ethanol was used as solvent. The solvents tert-butanol and iso-octane showed an enhancement of about 20 and 17% in the enzyme activity in 6 h of exposure, respectively. Novozym 435 and Lipozyme IM presented high stability to storage after treatment under ultrasound-assisted system using n-hexane and tert-butanol as solvents.

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In this work the adsorption features of Na Y zeolite with the magnetic properties of iron oxides have been combined in a composite to produce a magnetic adsorbent. These magnetic composites can be used as an adsorbent for metallic contaminants in water and subsequently removed from the medium by a simple magnetic process. The zeolites:iron oxide magnetic composites, were prepared by using Na Y with weight ratio of 3:1 and were characterized by powder X-ray diffraction (XRD), magnetization measurements, chemical analyses, N(2) adsorption isotherms and Mössbauer spectroscopy. Nitrogen adsorption isotherms showed that the surface area decreased from 505 m(2)g(-1) for the pure Na Y to 353 m(2)g(-1) for the Na Y:Fe oxide 3:1 composite. The adsorption isotherms of metal ions Cr(3+), Cu(2+) and Zn(2+) from aqueous solution onto the composites also showed that the presence of iron oxide does not affect the adsorption capacity.

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