SBA-15 Nanoparticles Research Articles

Enhanced Nanofiltration Performance of the PVC/PVA Thin Film Membranes for Treatment of Petroleum Refinery Wastewater through Incorporation of Amino-functionalized SBA-15 Nanoparticles

Enhanced Nanofiltration Performance of the PVC/PVA Thin Film Membranes for Treatment of Petroleum Refinery Wastewater through Incorporation of Amino-functionalized SBA-15 Nanoparticles

Physicochemical properties of functionalized A200 and SBA-15 nanoparticles with enhanced amphiphilicity for Pickering emulsions

Pickering emulsions stabilized by functionalized A200 and SBA-15 nanoparticles showed different stabilities, where the former was highly stable to be O/W and the latter was susceptible to a phase inversion from O/W to W/O type.

Orange Carotenoid Protein in Mesoporous Silica: A New System towards the Development of Colorimetric and Fluorescent Sensors for pH and Temperature.

Orange carotenoid protein (OCP) is a photochromic carotenoprotein involved in the photoprotection of cyanobacteria. It is activated by blue-green light to a red form OCPR capable of dissipating the excess of energy of the cyanobacterial photosynthetic light-harvesting systems. Activation to OCPR can also be achieved in the dark. In the present work, activation by pH changes of two different OCPs-containing echinenone or canthaxanthin as carotenoids-is investigated in different conditions. A particular emphasis is put on OCP encapsulated in SBA-15 mesoporous silica nanoparticles. It is known that in these hybrid systems, under appropriate conditions, OCP remains photoactive. Here, we show that when immobilised in SBA-15, the OCP visible spectrum is sensitive to pH changes, but such a colorimetric response is very different from the one observed for OCP in solution. In both cases (SBA-15 matrices and solutions), pH-induced colour changes are related either by orange-to-red OCP activation, or by carotenoid loss from the denatured protein. Of particular interest is the response of OCP in SBA-15 matrices, where a sudden change in the Vis absorption spectrum and in colour is observed for pH changing from 2 to 3 (in the case of canthaxanthin-binding OCP in SBA-15: λMAX shifts from 454 to 508 nm) and for pH changing from 3 to 4 (in the case of echinenone-binding OCP in SBA-15: λMAX shifts from 445 to 505 nm). The effect of temperature on OCP absorption spectrum and colour (in SBA-15 matrices) has also been investigated and found to be highly dependent on the properties of the used mesoporous silica matrix. Finally, we also show that simultaneous encapsulation in selected surface-functionalised SBA-15 nanoparticles of appropriate fluorophores makes it possible to develop OCP-based pH-sensitive fluorescent systems. This work therefore represents a proof of principle that OCP immobilised in mesoporous silica is a promising system in the development of colorimetric and fluorometric pH and temperature sensors.

Evaluation of tumor growth remission in a murine model for subcutaneous solid tumors – Benefits of associating the antitumor agent crotamine with mesoporous nanosilica particles to achieve improved dosing frequency and efficacy

Crotamine is a highly cationic polypeptide first isolated from South American rattlesnake venom, which exhibits affinity for acidic lysosomal vesicles and proliferating cells. This cationic nature is pivotal for its in vitro cytotoxicity and in vivo anticancer actions. This study aimed to enhance the antitumor efficacy of crotamine by associating it with the mesoporous SBA-15 silica, known for its controlled release of various chemical agents, including large proteins. This association aimed to mitigate the toxic effects while amplifying the pharmacological potency of several compounds. Comprehensive characterization, including transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential analysis, confirmed the successful association of crotamine with the non-toxic SBA-15 nanoparticles. The TEM imaging revealed nanoparticles with a nearly spherical shape and variations in uniformity upon crotamine association. Furthermore, DLS showed a narrow unimodal size distribution, emphasizing the formation of small aggregates. Zeta potential measurements indicated a distinct shift from negative to positive values upon crotamine association, underscoring its effective adsorption onto SBA-15. Intraperitoneal or oral administration of crotamine:SBA-15 in a murine melanoma model suggested the potential to reduce the frequency of crotamine doses without compromising efficacy. Interestingly, while the oral route enhanced the antitumor efficacy of crotamine, pH-dependent release from SBA-15 was observed. Thus, associating crotamine with SBA-15 could reduce the overall required dose to inhibit solid tumor growth, bolstering the prospect of crotamine as a potent anticancer agent.

Determination of the Isotopic Composition of Aqueous Mercury in a Paddy Ecosystem Using Diffusive Gradients in Thin Films.

Measuring the isotopic composition of Hg in natural waters is challenging due to the ultratrace level of aqueous Hg (ng L-1). At least 5 ng of Hg mass is required for Hg isotopic analysis. Given the low Hg concentration in natural waters, a large volume of water (>10 L) is typically needed. The conventional grab sampling method is time-consuming, laborious, and prone to contamination during transportation and preconcentration steps. In this study, a DGT (diffusive gradients in thin films) method based on aminopropyl and mercaptopropyl bi-functionalized SBA-15 nanoparticles was developed and extended to determine the concentration and isotopic composition of aqueous Hg for the first time. The results of laboratory analysis showed that Hg adsorption by DGT induces ∼ -0.2‰ mass-dependent fractionation (MDF) and little mass-independent fractionation (MIF). The magnitude of MDF exhibits a dependence on the diffusion-layer thickness of DGT. Since Hg-MDF can occur in a broad range of environmental processes, monitoring the δ202Hg of aqueous Hg using the DGT method should be performed with caution. Field results show consistent MIF signatures (Δ199Hg) between the DGT and conventional grab sampling method. The developed DGT method serves as a passive sampling method that effectively characterizes the MIF of Hg in waters to understand the biogeochemical cycle of Hg at contaminated sites.

Towards superior permeability and antifouling performance of sulfonated polyethersulfone ultrafiltration membranes modified with sulfopropyl methacrylate functionalized SBA-15

A non-solvent induced phase separation (NIPS) process was used to fabricate a series of sulfonated polyethersulfone (SPES) membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration (UF) process. SBA-15 was modified with 3-methacrylate-propyltrimethoxysilane (MPS) to form SBA-15-g-MPS. It was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium salt. The nanoparticles were uniformly dispersed and finger-like channels were developed within the membrane. The adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability, hydrophilicity, and antifouling properties. The pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES membrane. For the membrane containing 5% (mass) of SBA-15-g-PSPA (MSSPA5), the pure water flux was increased dramatically to 402.15 L∙m –2 ∙h –1 , which is ∼ 1.5 times that of MSSPA0 (268.0 L∙m –2 ∙h –1 ). The high flux rate was achieved with 3% (mass) of SBA-15 nanoparticles with retained high rejection ratio 98% for natural organic matter. The results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications.

Removal of Penicillin G from aqueous medium by PPI@SBA-15/ZIF-8 super adsorbent: Adsorption isotherm, thermodynamic, and kinetic studies

In the present paper, synthesis of SBA-15 nanoparticles was carried out from tetraethyl orthosilicate (TEOS) precursor using the sol-gel process. After being combined with Poly propylene imine, and ZIF-8 they were employed for the removal of Penicillin G. The synthesized combination morphology was assessed using nitrogen adsorption and desorption (BET), Fourier transform infrared (FTIR) spectroscopy, and X-ray powder diffraction (XRD). The parameters affecting Penicillin G removal, including pH, amount of adsorbent, time of contact, temperature, and concentration, were optimized, and the optimum levels of the mentioned variables were reported to be pH = 3, 0.03 g, 90 min, 25 °C, and 100 ppm, respectively. In addition, application of Freundlich, Langmuir, Dubinin–Radushkevhch, and Tempkin models and pseudo-first-order and pseudo-second-order adsorption synthetic equations aimed at determining the type of adsorbent isotherm. The results showed that the best fitting of Langmuir (R2 = 0.9944, qm = 400 mg/g) for adsorption isotherm and pseudo-second-order model (R2 = 0.9905) for kinetics studies. Furthermore, data of Gibbs free energy and enthalpy demonstrated an exothermic and spontaneous process in the research.

Immobilization of Orange Carotenoid Protein on mesoporous silica SBA-15 for the development of photoactivable nanodevices

The photoactive Orange Carotenoid Protein (OCP) is a protein involved in photo-protective responses in cyanobacteria. It induces the thermal dissipation of excess solar energy counteracting oxidative stress and photodamage. OCP consists of two structural domains sharing a non-covalently linked carotenoid as a cofactor. Blue light induces photoactivation of OCP and its colour changes from orange to red. In this work we have immobilized OCP on different kinds of raw and surface-functionalized SBA-15 mesoporous silica nanoparticles and structurally characterized the systems. SBA-15 matrices have demonstrated to be suitable supports for OCP, whose immobilization is strongly enhanced by the pre-photoactivation of the protein. OCP remains photoactive inside the mesoporous silica matrix, thereby producing photochromic nanoparticles. Under appropriate conditions OCP can also be released from SBA-15 nanoparticles. This work is a first step to understand the influence of matrix constraints and confinement on OCP photocycle. Furthermore, this study demonstrates that the OCP@SBA-15 system can be used as a photochromic material and as a possible optical device for nanoscale applications. Finally, this work is a first step towards the development of caroteno-protein and carotenoid release-strategies from silica matrix to be applied in the field of antioxidant drug delivery. • Orange Carotenoid Protein was efficiently adsorbed on SBA-15 up to 93 mg/g of solid material. • Orange Carotenoid Protein remains photoactive when immobilized. • Orange Carotenoid Protein immobilization was more efficient on SBA-15 functionalized with amino groups. • Orange Carotenoid Protein adsorption on SBA-15 was partially reversible upon change of pH and ionic strength. • The amount of immobilized Orange Carotenoid Protein was enhanced when the adsorption process takes place upon illumination.

Preparation of Amino-Functionalized Mesoporous SBA-15 Nanoparticles and the Improved Adsorption of Tannic Acid in Wastewater.

Ordered mesoporous Santa Barbara amorphous (SBA-15) materials have high surface areas and are widely used in adsorption, separation, filtration, and heterogeneous catalytic processes. However, SBA-15 surfaces contain hydroxyl groups that are unsuited to the adsorption of organic pollutants; thus, SBA-15 must be chemically modified to promote its adsorption activity. In this study, amino-functionalized nanoporous SBA-15 was fabricated by employing sodium silicate as a precursor. The structural characteristics of the prepared composites were examined using thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectrometry, field-emission scanning electron microscopy, transmission electron microscopy, and surface area analysis. The prepared SBA-15 had a large pore size (6.46–7.60 nm), large pore volume (1.037–1.105 cm3/g), and high surface area (546–766 m2/g). Functionalization caused a reduction in the SBA-15 pore volume and surface area, whereas amino groups that promoted an interaction between adsorbates and solids facilitated solute adsorption. The adsorption of tannic acid (TA) onto amino-modified silica composites (SBA-15 and 3-aminopropyltriethoxysilane (SBA-15/APTES) and SBA-15 and pentaethylenehexamine (SBA-15/PEHA)) was studied. Their adsorption capacities were affected by solution temperature, solution pH, agitation speed, adsorbent dosage, and initial TA concentration. The maximum adsorption capacities for SBA-15/APTES and SBA-15/PEHA were 485.18 and 413.33 mg/g, respectively, with SBA-15/APTES exhibiting ultrafast removal of TA (98.61% removal rate at 15 min). In addition, this study explored the thermodynamics, adsorption isotherms, and kinetics. A comparison of two types of amino-functionalized SBA-15 was used for the first time to adsorb TA, which providing valuable information on TA adsorption on high adsorption capacity materials in water media.

Unit-cell wide SBA-15 type mesoporous silica nanoparticles

With large and 2D hexagonally ordered mesopores, SBA-15 is the superstar among mesoporous silicas reported so far and has found many applications. To prepare SBA-15 nanoparticles is of particular interest for biomedical application yet remains challenging. In this work, rod-shaped SBA-15 nanoparticles (SBA-15NPs), with 2–3 mesopore channels in width (called unit-cell wide) and averaged length of 94.8 nm, are for the first time prepared in a boric acid catalyzed P123 templating system based on the partitioned cooperative self-assembly principle in a one-pot preparation. The BET surface area and total pore volume of typical SBA-15NPs reach 553 m2g-1 and 1.52 cm3g-1, respectively. The preparation of SBA-15NPs relies on PCSA process that bestows long and thin tubular SBA-15 pre-structures with many defects in low-temperature synthesis step, which are then cut into SBA-15NPs by a sulfuric acid enhanced Ostwald ripening process in hydrothermal treatment step. In enzyme adsorption tests, SBA-15NPs demonstrate higher capacity and faster adsorption compared with conventional rod-shaped SBA-15.

Cu(II)-Based Ionic Liquid Supported on SBA-15 Nanoparticles Catalyst for the Oxidation of Various Alcohols into Carboxylic Acids in the Presence of CO2

Cu(II)-Based Ionic Liquid Supported on SBA-15 Nanoparticles Catalyst for the Oxidation of Various Alcohols into Carboxylic Acids in the Presence of CO2

Towards to better permeability and antifouling sulfonated poly (aryl ether ketone sulfone) with carboxyl group ultrafiltration membrane blending with amine functionalization of SBA-15

A series of sulfonated poly (aryl ether ketone sulfone) with carboxyl groups (C-SPAEKS) blending with amine functionalization of SBA-15 particles were fabricated by the phase inversion method applied in ultrafiltration (UF) field. The 4-carboxyphenyl hydroquinone (4C-PH) and sulfonated poly (aryl ether ketone sulfone) with carboxyl groups (C-SPAEKS) were demonstrated by 1H NMR spectra and the FT-IR. The scanning electron microscope (SEM) showed that the nanoparticles were evenly distributed and finger-like channels were formed in the film. The task results showed that the amine functionalization of SBA-15 particles greatly increased the hydrophilicity, water fluxes and antifouling properties of membranes. The pure water flux of C-SPAEKS membrane and hybrid membrane were 259 (L/m2h) and 564 (L/m2h), respectively, which were much higher than those of conventional UF membrane. The pure water flux of hybrid membrane with the concentration of 0.1% nanoparticles was 419 (L/m2h) and at the same time the membrane maintained highly rejection (96%) with higher FRR (93%). In short, all the results indicated that sulfonated poly (aryl ether ketone sulfone) with carboxyl groups (C-SPAEKS) and hybrid membrane blending with amine functionalization of SBA-15 nanoparticles have the great prospect in ultrafiltration.

Dual stimuli-responsive silver nanoparticles decorated SBA‒15 hybrid catalyst for selective oxidation of alcohols under ‘mild’ conditions

Herein, we develop an efficient and novel catalytic system, i.e. silver nanoparticles (AgNPs) incorporated mesoporous silica SBA‒15/copolymer hybrid material, for selective oxidation of different alcohols to aldehydes or ketones under ‘mild’ conditions. The copolymer of N,-N -dimethylaminoethyl methacrylate and 2-hydroxyethyl acrylate (p(DMAEMA- co -HEA)) was used to graft the surface-modified SBA‒15 (MS) using free radical polymerization method. Then AgNPs were decorated on the polymer grafted SBA‒15. The dual (thermal and pH) responsive behaviors of the AgNPs/p(DMAEMA- co -HEA)/MS catalyst were investigated using the dynamic light scattering technique. The lower critical solution temperature (LCST) of the copolymer was found to be approximately 30–35 °C. The catalytic activity of AgNPs/p(DMAEMA- co -HEA)/MS was investigated for the selective oxidation of different alcohols to aldehydes or ketones. The conversion of catalytic products and selectivity were calculated using gas chromatographic techniques, whereas the molecular structure of products was determined using 1 H and 13 C nuclear magnetic resonance spectroscopy. The catalyst showed improved catalytic activity toward the oxidation of alcohols to aldehydes in aqueous medium below LCST and pKa value (7–7.5) of the copolymer. The selectivity toward the corresponding aldehyde was found to be significantly high (99%). The main advantages of the hybrid catalyst as compared to existing catalysts include outstanding alcohol conversion (up to 99%), short reaction time (1 h), small necessary amount of catalyst (6 mg), and performing the catalytic conversion at room temperature using water as a solvent, which are highly beneficial for organic conversion under mild reaction conditions. • A catalytic system for selective oxidation of alcohols under ‘mild’ conditions was developed. • The catalyst consists of a temperature and pH-responsive copolymer, SBA-15, and Ag nanoparticles. • The catalyst showed outstanding alcohol conversion (up to 99%) within a short reaction time (1 h). • The catalyst performed the catalytic conversion at room temperature using water as a solvent.

Thin film nanocomposite membranes filled with MCM-41 and SBA-15 nanoparticles for brackish water desalination via reverse osmosis

This work aimed to investigate the impact of filling MCM-41 and SBA-15 nanoparticles (NPs) on the performance of thin film nanocomposite membranes that applied in reverse osmosis, where SBA-15 is firstly reported here for this purpose. The membranes were prepared via the interfacial polymerization reaction between m -phenylenediamine (MPD) aqueous solution and trimesoyl chloride (TMC)-isooctane solution on a support sheet of polyethersulfone. The reaction time in the presence of NPs was investigated by fixing MPD contact time at 75 s; it was found that 30 s is the optimum TMC contact time. Different loading ratios in the range of 0-0.15 wt% were applied to fill the NPs inside the membranes. Scanning electron microscope (SEM), X-ray Diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), and N 2 adsorption/desorption tests were used to study the NPs characterizations. While SEM, contact angle, mechanical strain and strength, and membrane performance tests were conducted to study the membranes properties. Results showed that in both nanoparticles (i.e. MCM-41 and SBA-15) cases, 0.1 wt% was the optimum filling percentage. When SBA-15 was loaded, water flux increased from 40 to 74.17 L.m −2 .h −1 (LMH), and NaCl rejection increased from 95.1 to 98.5% comparing with the plain membrane. While when the optimum MCM-41 ratio was loaded, water flux and NaCl rejection raised to 60 LMH and 96.9%, respectively. The performance test conditions were 15 bar, 25 °C, and 2500 NaCl feed concentration. • MCM-41 and SBA-15 NPs were filled in TFN membranes. • Both additives improved the membranes performance. • SBA-15 is firstly reported as a filler for RO application. • SBA-15 effect was higher on the membranes water flux and salt rejection.

Influence of modified mesoporous silica SBA-15 and compatibilizer on the properties and structure of ethylene-vinyl acetate copolymer-based nanocomposites

ABSTRACT Three series of poly(ethylene-co-vinyl acetate)/mesoporous silica type SBA-15 (EVA/SBA-15) nanocomposites, containing 1, 2, 3, and 4 wt% SBA-15 nanoparticles were prepared by melt blending in internal mixer. The mesoporous silica SBA-15 was synthesized by the sol-gel method and organomodified by Hexadecyltrimethoxysilane (HDTMS). The terpolymer of Ethylene-butyl acrylate-maleic anhydride (E-BA-MA) containing 6% butylacrylate, 3% maleic anhydride was added as compatibilizer at 2 wt% to nanocomposites including unmodified SBA-15. The chemical and physical properties of EVA/SBA-15 nanocomposites were characterized by infrared spectroscopy (FTIR), calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and rheology. The results confirmed that HDTMS was successfully incorporated into the surface of SBA-15. The crystallinity of the matrix decreased and Young’s modulus increased with the incorporation of the filler and in the presence of terpolymer as compatibilizer, whereas elongation at break and tensile strength kept almost the values of the matrix. The thermal stability of nanocomposites was enhanced as compared with the pure EVA matrix.

Adsorption of ternary toxic crystal violet, malachite green and methylene blue onto synthesised SBA-15 mesoporous nanoparticles

ABSTRACT In this research, SBA-15 mesoporous silica nanoparticles were synthesised and characterised using different techniques. Average particle size of synthesised SBA-15 was obtained to be 16 and 33.6 nm from field emission scanning electron microscopy image and X-ray diffraction analysis, respectively. Response surface methodology indicated that 70 mg L−1 initial dye concentrations, 0.1 g L−1 adsorbent dosage, 14 min contact time and pH 9, result in the best adsorption capacity of SBA-15 nanoparticles. According to analysis of variance, the most important factor on the adsorption of all dyes onto SBA-15 nanoparticles was adsorbent dosage. The equilibrium data were fitted by Langmuir isothermal model and adsorption kinetic data are more similar to the pseudo-first-order model. The thermodynamic analysis suggested that the adsorption of crystal violet (CV) and malachite green (MG) dyes on the SBA-15 nanoparticle is a spontaneous and endothermic process, meanwhile sorption of methylene blue (MB) dye was found exothermic. Also, the ΔG 0 value in the range of −0.27 to −7.1 kJ mol−1 revealed that adsorption of three dyes on SBA-15 nanoparticles was physisorption. Finally, performance of the developed model was applied for the removal of these dyes in river water and simulated industrial wastewater.

Needleless electrospinning of PAN/SBA-15 for the preparation of nanofibers membranes

Polyacrylonitrile is one of the few waterproof polymers that can be spun from relatively safe solvents, facilitating the use of PAN nanofibers membranes in medical, filtration and biological applications. In this study PAN nanofiber membranes containing SBA-15 nanoparticles were prepared by the process of electrospinning in needless electrospinning machine and DMSO was used as solvent. A small amount of dispersing agent BYK W-9010 was added for a better deagglomerating of SBA-15 nanoparticles in the PAN/DMSO solution. The influence of rod like SBA-15 type ordered mesoporous silica particles as filler on the morphology and textural parameters of electrospun PAN nanofibers was studied. The effect of concentration, applied voltage, distance and feed rate on nanofibers diameter was investigated. The results obtained demonstrated that by increasing the concentration, applied voltage and feed rate, the number of nanofibers was increased and thicker nanofibers were obtained. Viscosity increased by increasing the concentration of polymer and it increased further by imparting small amount of silica nanoparticles. The SEM images of nanofibers were taken and their morphology explains that presence of silica nanoparticles in the nanofibers increases the specific surface area and makes the surface rough.

Detection of low concentration acetone utilizing semiconductor gas sensor

Acetone gas sensor plays a key role in air monitoring and non-invasive diagnosis of diabetes. In the present study, two different types of SnO2 semiconductor gas sensors have been fabricated to detect trace acetone. These gas sensors include mesoporous SnO2 sensor synthesized via nanocasting approach using the hard template of mesoporous SBA-15 and bulk SnO2 nanoparticles sensor synthesized by chemical precipitation method. The acetone sensing properties of the SnO2 sensors were evaluated, and the sensing mechanism of the mesoporous SnO2 sensor was proposed. The mesoporous SnO2 sensors achieve higher sensing response to acetone than the bulk SnO2 nanoparticles sensor. Moreover, the mesoporous SnO2 sensor could detect as low as 0.5 ppm acetone and exhibit high selectivity to acetone. Results demonstrate that high surface area and ordered mesoporous SnO2 sensor can considerably enhance the sensing properties to acetone. Therefore, the ordered mesoporous SnO2 sensor provides a robust candidate for trace acetone detection.

Synthesis of Poly (Vinylidene Fluoride)/Modified SBA-15 Nanoparticles Composite Membrane for Water Purification

One of the methods of pollution separating from urban and industrial wastewater is the use of composite membranes based on polymer. The modified composite polymer has high mechanical resistance and improved heat, which is an appropriate option to use as a membrane infiltration method. In this study, to improve the polymer membrane of polyvinylidene fluoride (PVDF) is used the modification of mesoporous silica nanoparticles (SBA–15). The mesoporous silica nanoparticles (SBA-15) are made by the sol-gel method witch in this method is using a precursor of Tetra-ethyl-ortho silicate (TEOS) in the presence of a copolymer Pluronic P123 (as mould and for maintaining the structure after solvent exiting) and has been calcined at 600 °C. The surface modifies of SBA-15 is used from (3-chloropropyl) trimethoxysilane and Triron-100 for 24 h in the presence of argon gas by the post-synthesis method. Subsequently, the physical characteristics are investigated by using nitrogen adsorption and desorption analysis (BET), scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), thermal analysis (TGA) and X-ray diffraction pattern (XRD). The FT-IR analysis and thermal analysis confirmed the complete transmitting of mould during thermal operation. So, according to the results of nitrogen absorption and desorption, powders synthesized based on IUPAC categorization, have hysteresis IV which confirms cavities in the area of meso. Accordingly, the specific surface of the samples is 640 m2.g−1, the volume of cavities is 1.2 cm3.g−1 and the diameter of cavities is 6.2 nm. Moreover, the BJH graph indicated the cavities with a narrow size distribution. The results showed that adding a small amount of modified SBA-15 nanoparticles to PVDF can effectively increase the membrane’s hydrophilicity, mechanical properties, antifouling performance, and thermal stability, increase membrane flux and salt rejection.

Cu/TCH-pr@SBA-15 nano-composite: a new organometallic catalyst for facile three-component synthesis of 4-arylidene-isoxazolidinones.

A copper complex supported on SBA-15 nanoparticles (Cu/TCH-pr@SBA-15) was synthesized by the post-synthesis modification of nano-mesoporous silica with 3-chloropropyltriethoxysilane (CPTES) and thiocarbohydrazide (TCH) and subsequent metal–ligand coordination with Cu(ii). These nanocomposites were thoroughly characterized by FT-IR spectroscopy, TEM, FE-SEM, EDX, atomic absorption spectroscopy and N2 adsorption–desorption (BET) studies. Then, a solvent-free method was developed for the three-component synthesis of 4-arylidene-isoxazolidinones via condensation of hydroxylamine hydrochloride, ethyl acetoacetate and various aromatic aldehydes using Cu/TCH-pr@SBA-15 as a highly efficient nanocatalyst. This new economic and eco-friendly methodology has remarkable advantages such as excellent yields, a shorter reaction time, an easy purification procedure, simplicity, green conditions, solvent-free conditions, and recoverability of the nanocatalyst.