Journal of Porous Materials最新文献

The oxidative dehydrogenation of propane (ODP) using CO₂ offers a promising route to propylene production, as CO₂ acts as a milder oxidant than O₂. This study focuses on the synthesis and characterization of CrO_x/MCM-41 catalysts prepared by co-precipitation of chromium nitrate and tetraethyl orthosilicate (TEOS) in the presence of the C16TMABr template. The resulting MCM-41-supported catalysts, along with the initial MCM-41 support, were characterized by N₂ physisorption, TG-DTG-DTA, XRD, FT-IR spectroscopy, SEM-EDS, UV-Vis DRS, XPS, TPR-H₂, and small-angle X-ray scattering. Analysis revealed that Cr in the 1-5Cr_inc/MCM-41 samples primarily exists as Cr⁶⁺, while in the 7-9Cr_inc/MCM-41 samples, both Cr³⁺ and Cr⁶⁺ are present, with Cr³⁺ being the dominant species. Catalytic testing conducted at an atmospheric pressure in the temperature range of 550–750 °C showed that the 5Cr_inc/MCM-41 and 3Cr_inc/MCM-41 catalysts achieved the highest propylene selectivity (68% at 575 °C with a 19% propane conversion and 69% at 600 °C with a 13% propane conversion, respectively). Notably, the incorporated Cr_inc/MCM-41 catalysts exhibited a 1.5–2.5 times higher productivity compared to supported Cr/MCM-41 catalysts.

Magnetic silica molecular sieves have garnered significant attention for their combined molecular sieving properties and magnetic responsiveness, offering promising applications in catalysis and environmental remediation. This study systematically investigates the hydrothermal synthesis of silicalite-1 composites incorporating transition metal ferrites (Mg, Zn, Ni, Co) to develop magnetically separable molecular sieves. Through controlled variation of synthesis parameters including template concentration, water-to-silicon ratio, crystallization temperature and duration, we established optimal conditions yielding well-defined crystalline materials with preserved framework integrity. Comprehensive characterization through vibrating sample magnetometry, X-ray diffraction, and electron microscopy revealed that the incorporated magnetic nanoparticles (12–18 nm) maintain their spinel structure while causing only minimal distortion to the host molecular sieve matrix. The optimized composites demonstrated tunable soft magnetic properties with saturation magnetization values spanning 0.52–16.13 emu/g, dependent on ferrite composition and loading. Notably, the synthesis protocol achieved precise control over particle size (400–600 nm) and crystallinity while enabling efficient magnetic separation. This work provides fundamental insights into the structure-property relationships of magnetic zeolite composites, establishing a robust platform for their rational design in advanced separation and catalytic applications.

Oil pollution poses significant environmental challenges, necessitating the development of effective and sustainable solutions for oil absorbents. In this work, sodium alginate (ALG) and soy protein isolate (SPI) were combined via a sol–gel method, followed by surface functionalization using methyltrimethoxysilane (MTMS) and tetraethyl orthosilicate (TEOS) and dried by supercritical carbon dioxide (scCO₂) to produce a hybrid aerogel oil absorbent. ALG concentration was varied from 1 to 3% w/w, while SPI concentrations were constant at 0.5 and 1.5% w/w. Results showed that the one-step surface modification successfully changed the ALG/SPI aerogel to hydrophobic. ALG/SPI aerogels are capable of absorbing model pollutants (i.e., waste engine oil, heavy-duty oil and chloroform) ranging from 1.34 to 10.3 g/g, with the highest absorption efficiency reaching 91%. Notably, ALG/SPI 1_1.5 appears as the most effective, absorbing waste oil at temperatures from 40 to 80 °C, has a high surface area (210 m²∙g⁻¹), lightweight (0.107 g·cm⁻³), thermally stable over 196 °C, and is reusable up to four times. ALG/SPI aerogel remains afloat, retaining absorbed pollutants and is biodegradable, hence reducing post-use environmental impact. This study demonstrated that the hybrid ALG/SPI aerogels are promising materials as oil absorbents in the oil/water separation industry.

In this study, we developed a novel drug delivery system, PAA-2@pSiNPs@1, designed to enhance drug loading capacity and control drug release, particularly for the treatment of AMI. The composite material was synthesized by incorporating PAA-2 into pSiNPs, with compound 1 successfully encapsulated within the structure. The PAA-2 coating significantly influenced the drug release kinetics, improving the stability of the drug-loaded nanoparticles. Furthermore, the PAA-2@pSiNPs@1 system demonstrated excellent selective detection of Troponin in complex environments, making it especially suitable for AMI diagnosis and monitoring. Additionally, drug release studies were conducted in phosphate-buffered saline (PBS) at different pH values (pH 7.4, 6.5, and 4) to simulate physiological conditions. The results revealed pH-dependent release characteristics. At physiological pH (7.4), drug release was slow, whereas at lower pH values, the release rate was faster, showcasing the system’s potential for controlled drug release. The composite material exhibited high drug loading efficiencies for both hydrophilic and hydrophobic drugs, such as DOX, paclitaxel (PTX), and SN-38, further confirming its broad applicability in various drug delivery systems. Finally, using an ischemia/reperfusion (I/R) injury model in H9c2 cells, we evaluated the inhibitory effect of PAA-2@pSiNPs@1 on oxidative stress-induced myocardial cell damage.

Ciprofloxacin (CIP), a widely used fluoroquinolone antibiotic, has emerged as a significant pharmaceutical contaminant in water bodies, raising environmental and public health concerns due to its persistence and resistance to conventional wastewater treatment methods. This study reports the fabrication and application of a highly porous, cross-linked graphene nanoplatelets/polyvinyl alcohol (GNP/PVA) composite aerogel for the adsorption-based removal of CIP from aqueous solutions. The aerogel was synthesized via solution casting and freeze-drying, with maleic acid serving as the cross-linking agent. Characterization using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TGA) confirmed the aerogel’s porous structure, chemical cross-linking, and thermal stability. The adsorption of CIP by the aerogel was investigated through a batch adsorption process, optimizing various parameters such as solution pH, aerogel dosage, and initial CIP concentration over a three-day period. The optimization revealed that the adsorption process was most efficient at pH 4, using 60 mg of aerogel and an initial CIP concentration of 23 ppm. Under these conditions, the cross-linked GNP/PVA aerogel demonstrated promising potential for effective CIP removal, highlighting its applicability for treating pharmaceutical-laden effluents in municipal and hospital wastewater systems.

Hemoperfusion is a promising alternative to hemodialysis, particularly for removing protein-bound uremic toxins such as p-Cresol, which are poorly eliminated by conventional dialysis due to their strong affinity to plasma proteins. However, current adsorbents often suffer from limited adsorption efficiency and poor biocompatibility. This study presents the development of α-mangostin-loaded silica nanoparticles to enhance both adsorption performance and biocompatibility for potential blood purification applications. Mesoporous silica nanoparticles (15–25 nm) were synthesized and functionalized with 0.5 and 1.5 wt% α-mangostin. Their performance was evaluated through p-Cresol adsorption and nitric oxide scavenging assays. At an initial p-Cresol concentration of 250 mg/L, the adsorption capacities of pure α-mangostin, silica, silica/0.5mangostin, and silica/1.5mangostin were 15.87, 197.67, 179.49, and 185.67 mg/g, respectively. The incorporation of α-mangostin preserved silica’s adsorption capacity while enhancing antioxidant properties. Compared to plain silica, the α-mangostin-loaded nanoparticles increased clotting time by 21.5% and reduced reactive oxygen species by 36%, indicating improved biocompatibility. These results suggest that α-mangostin-loaded silica nanoparticles are promising candidates for multifunctional adsorbents with enhanced biocompatibility for blood purification.

SiO₂ aerogel has broad application prospects in thermal insulation fields such as aerospace, industrial energy conservation, and building energy saving. However, the high preparation cost and poor high-temperature stability limit its large-scale industrial production and application. Herein, CaSO₄-modified SiO₂ aerogel (SC) with low cost and high thermal stability was synthesized from water glass and CaSO₄ via the sol-gel and supercritical drying route. The effect of CaSO₄ doping amount on the morphology, pore structure and physical properties of SC was investigated. Results show that the effective doping of CaSO₄ can significantly improve the heat resistance ability of SC at the temperature of 800–1000 ℃. After heated at 800 ℃ for 2 h, the weight loss of the modified aerogels was less than 7%, and the volume shrinkage rate was as low as 4%. The specific surface area of SCs (≥ 166 m²/g) after calcined at 1000 ℃ for 2 h were higher than that of the unmodified aerogels (119 m²/g). Mechanism analysis shows that not only Ca²⁺ can replace the active group Si-OH on the surface of the gel, reducing the intrinsic surface energy and sintering driving force of the gel particles and but also the Ca₂SiO₄ second phase is generated during the heating process, which hinders the contact growth of the particles and further improves the temperature resistance of the aerogel. These findings propose feasible ideas and methods for the application of SiO₂ aerogel materials in high-temperature thermal insulation.

In this work, the analysis and generalization of data on the elemental, phase and surface composition, crystal structure and microstructure of MFI-type HZSM-5 with Si/Al = 12, 25, 40, 300 were presented. Relationships between the composition of zeolite in HZSM-5 samples with different Si/Al and pore volume, specific surface, and framework voids area were established. Data obtained by electron microscopy and energy dispersive X-ray microanalysis explained the discrepancy between HZSM-5 real composition and the initial (as synthesized) one. Samples with the maximum content of Brønsted (HZSM-5 with Si/Al = 25) and Lewis (HZSM-5 with Si/Al = 12) acid sites responsible for the catalytic activity were identified using diffuse reflectance Fourier transform infrared spectroscopy. N₂O decomposition reaction rate was found to decrease in the row HZSM-5(25) > HZSM-5(12) > HZSM-5(40) > HZSM-5(40)C > > HZSM-5(300). The high N₂O decomposition rate demonstrated by HZSM-5(25) makes it promising catalyst. The second phase of iron oxides, found in all studied HZSM-5 as an impurity of the initial components, and the presence of faceted particles {001} oriented in HZSM-5(25) were shown to contribute to its maximum catalytic activity in N₂O decomposition. The applied methodology for studying aluminosilicalites with different silicon to aluminum ratio and the revealed correlations can provide a fundamental perspective in studying other zeolites.

In this study, pH-responsive drug delivery system was prepared by magnetic mesoporous silica synthesis through hydrothermal method followed by post-synthetic amino modification. The structure of the synthesized nanocomposite was characterized by XRD, FT-IR, VSM, XPS, TEM, SEM, N₂-adsorption/desorption, and surface charge density analyses. The nanocomposite, which was determined to have a remarkably stable mesostructure and superparamagnetic character, was used as drug carrier for both anionic character Indomethacin (IND) and cationic character Doxorubicin (DOX). IND, an anti-inflammatory drug, and DOX, an anticancer drug used in chemotherapy, must be used in high doses due to their low water solubility and lack of targeting ability, respectively. The loading capacities determined according to the adsorption equilibrium are quite high for both drugs (106.96 and 134.10 mg/g, for IND and DOX, respectively) due to electrostatic attraction and hydrogen bond formation. For IND, the release study was realized in phosphate buffer solutions (pH 7.4, 6.8 and 2.2) by mimicking the gastrointestinal tract; for DOX, human blood pH (7.4) and cancer cell pH (5.5) were selected as the release medium. IND exhibited increased release behavior at neutral pH (7.4, 39.5% release), while DOX exhibited increased release behavior at acidic pH (5.5, 39.7% release). Peppas-Sahlin and Korsmeyer-Peppas kinetic models effectively described the IND and DOX release behavior from the nanocomposite. Both IND and DOX could be loaded with high loading efficiency (85.36% and 88.88% for IND and DOX, respectively) onto the nanocomposite and pH-controlled release can be achieved, which may be inspiring for a bimodal nanomedical treatment approach.