Super-Assembled Multilayered Mesoporous TiO2 Nanorockets for Light-Powered Space-Confined Microfluidic Catalysis

In the field of sustainable chemistry, it is still a significant challenge to realize efficient light-powered space-confined catalysis and propulsion due to the limited solar absorption efficiency and the low mass and heat transfer efficiency. Here, novel semiconductor TiO2 nanorockets with asymmetric, hollow, mesoporous, and double-layer structures are successfully constructed through a facile interfacial superassembly strategy. The high concentration of defects and unique topological features improve light scattering and reduce the distance for charge migration and directed charge separation, resulting in enhanced light harvesting in the confined nanospace and resulting in enhanced catalysis and self-propulsion. The movement velocity of double-layered nanorockets can reach up to 10.5 μm s-1 under visible light, which is approximately 57 and 119% higher than that of asymmetric single-layered TiO2 and isotropic hollow TiO2 nanospheres, respectively. In addition, the double-layered nanorockets improve the degradation rate of the common pollutant methylene blue under sustainable visible light with a 247% rise of first-order rate constant compared to isotropic hollow TiO2 nanospheres. Furthermore, FEA simulations reveal and confirm the double-layered confined-space enhanced catalysis and self-propulsion mechanism.

Strontium and Zinc Co-Doped Mesoporous Bioactive Glass Nanoparticles for Potential Use in Bone Tissue Engineering Applications

Mesoporous bioactive glass nanoparticles (MBGNs) have attracted significant attention as multifunctional nanocarriers for various applications in both hard and soft tissue engineering. In this study, multifunctional strontium (Sr)- and zinc (Zn)-containing MBGNs were successfully synthesized via the microemulsion-assisted sol-gel method combined with a cationic surfactant (cetyltrimethylammonium bromide, CTAB). Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs exhibited spherical shapes in the nanoscale range of 100 ± 20 nm with a mesoporous structure. Sr and Zn were co-substituted in MBGNs (60SiO2-40CaO) to induce osteogenic potential and antibacterial properties without altering their size, morphology, negative surface charge, amorphous nature, mesoporous structure, and pore size. The synthesized MBGNs facilitated bioactivity by promoting the formation of an apatite-like layer on the surface of the particles after immersion in Simulated Body Fluid (SBF). The effect of the particles on the metabolic activity of human mesenchymal stem cells was concentration-dependent. The hMSCs exposed to Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs at 200 μg/mL enhanced calcium deposition and osteogenic differentiation without osteogenic supplements. Moreover, the cellular uptake and internalization of Sr-MBGNs, Zn-MBGNs, and Sr-Zn-MBGNs in hMSCs were observed. These novel particles, which exhibited multiple functionalities, including promoting bone regeneration, delivering therapeutic ions intracellularly, and inhibiting the growth of Staphylococcus aureus and Escherichia coli, are potential nanocarriers for bone regeneration applications.

Mesoporous RE0.5Ce0.5O2-x Fluorite Electrocatalysts for the Oxygen Evolution Reaction

Developing highly active and stable electrocatalysts for the oxygen evolution reaction (OER) is key to improving the efficiency and practical application of various sustainable energy technologies including water electrolysis, CO2 reduction, and metal air batteries. Here, we use evaporation-induced self-assembly (EISA) to synthesize highly porous fluorite nanocatalysts with a high surface area. In this study, we demonstrate that a 50% rare-earth cation substitution for Ce in the CeO2 fluorite lattice improves the OER activity and stability by introducing oxygen vacancies into the host lattice, which results in a decrease in the adsorption energy of the OH* intermediate in the OER. Among the binary fluorite compositions investigated, Nd2Ce2O7 is shown to display the lowest OER overpotential of 243 mV, achieved at a current density of 10 mA cm-2, and excellent cycling stability in an alkaline medium. Importantly, we demonstrate that rare-earth oxide OER electrocatalysts with high activity and stability can be achieved using the EISA synthesis route without the incorporation of transition and noble metals.

Amphiphilic Graft Copolymers as Templates for the Generation of Binary Metal Oxide Mesoporous Interfacial Layers for Solid-State Photovoltaic Cells

The binary metal oxide mesoporous interfacial layers (bi-MO meso IF layer) templated by a graft copolymer are synthesized between a fluorine-doped tin oxide (FTO) substrate and nanocrystalline TiO2 (nc-TiO2). Amphiphilic graft copolymers, Poly(epichlorohydrin)-graft-poly(styrene), PECH-g-PS, were used as a structure-directing agent, and the fabricated bi-MO meso IF layer exhibits good interconnectivity and high porosity. Even if the amount of ZnO in bi-MO meso IF layer increased, it was confirmed that the morphology and porosity of the bi-MO meso IF layer were well-maintained. In addtion, the bi-MO meso IF layer coated onto FTO substrates shows higher transmittance compared with a pristine FTO substrate and dense-TiO2/FTO, due to the reduced surface roughness of FTO. The overall conversion efficiency (η) of solid-state photovoltaic cells, dye-sensitized solar cells (DSSCs) fabricated with nc-TiO2 layer/bi-MO meso IF layer TZ1 used as a photoanode, reaches 5.0% at 100 mW cm-2, which is higher than that of DSSCs with an nc-TiO2 layer/dense-TiO2 layer (4.2%), resulting from enhanced light harvesting, good interconnectivity, and reduced interfacial resistance. The cell efficiency of the device did not change after 15 days, indicating that the bi-MO meso IF layer with solid-state electrolyte has improved electrode/electrolyte interface and electrochemical stability. Additionally, commercial scattering layer/nc-TiO2 layer/bi-MO meso IF layer TZ1 photoanode-fabricated solid-state photovoltaic cells (DSSCs) achieved an overall conversion efficiency (η) of 6.4% at 100 mW cm-2.

Phosphorus-doped TiO2mesoporous nanocrystals for anodes in high-current-rate lithium ion batteries

Limited by the intrinsic low electronic conductivity and inferior electrode kinetics, the use of TiO2as an anode material for lithium ion batteries (LIBs) is hampered. Nanoscale surface-engineering strategies of morphology control and particle size reduction have been devoted to increase the lithium storage performances. It is found that the ultrafine nanocrystal with mesoporous framework plays a crucial role in achieving the excellent electrochemical performances due to the surface area effect. Herein, a promising anode material for LIBs consisting of phosphorus-doped TiO2mesoporous nanocrystals (P-TMC) with ultrafine size of 2-8 nm and high specific surface area (234.164 m2g-1) has been synthesized. It is formed through a hydrothermal process and NaBH4assisted heat treatment for anatase defective TiO2(TiO2-x) formation followed by a simple gas phosphorylation process in a low-cost reactor for P-doping. Due to the merits of the large specific surface area for providing more reaction sites for Li+ions to increase the storage capacity and the presence of oxygen vacancies and P-doping for enhancing material's electronic conductivity and diffusion coefficient of ions, the as-designed P-TMC can display improved electrochemical properties. As a LIB anode, it can deliver a high reversible discharge capacity of 187 mAh g-1at 0.2 C and a good long cycling performance with ∼82.6% capacity retention (101 mAh g-1) after 2500 cycles at 10 C with an average capacity loss of only 0.007% per cycle. Impressively, even the current rate increases to 100 times of the original rate, a satisfactory capacity of 104 mAh g-1can be delivered, displaying good rate capacity. These results suggest the P-TMC a viable choice for application as an anode material in LIB applications. Also, the strategy in this work can be easily extended to the design of other high-performance electrode materials with P-doping for energy storage.

Fabrication of Mesoporous Materials Based on Supramolecular Self-Assembly of Guanosine Monophosphonate-Nickel Chloride (GMP-Ni) for High-Performance Hybrid Supercapacitors

Supramolecular self-assembly of nickel chloride and guanosine mono-phosphonate (GMP) and nickel (Ni)-based GMP-Ni and their calcinated mesoporous electrode materials GMP-Ni-500 and GMP-Ni-700 at 500 and 700 °C, respectively, have been fabricated. GMP-Ni, GMP-Ni-500, and GMP-Ni-700 are examined for their supercapacitor performance in a three-electrode configuration. The electrochemical tests demonstrate the mesoporous battery-type nature of GMP-Ni-500 which exhibited a specific capacity (Cs) of about 289 C g-1 at 0.5 A g-1 current density. In addition, a cost-effective and simple asymmetric supercapacitor device has been fabricated with battery-type GMP-Ni-500 as a cathode material and capacitive-type activated carbon (AC) as an anodic material. In an operating voltage window of 0 to 1.5 V, hybrid supercapacitors (HSCs) based on GMP-Ni-500//AC exhibited a remarkable performance with a specific capacity (Cs) of 144 C g-1 at 0.5 A g-1. For the HSC device, the maximum of 66% capacity retention has been observed after 5000 charging/discharging cycles at 5 A g-1. Furthermore, the HSC device demonstrates a high energy density of 24 W h kg-1 at a power density of 297 W kg-1. The molecular transformation was established by employing theoretical calculations. These results suggest that our HSC has outstanding potential in technology development for next-generation commercial applications.

Synthesis and characterization of mesoporous zinc oxide nanoparticles and evaluation of their biocompatibility in L929 fibroblasts

OBJECTIVES

This study aimed to synthesize and characterize mesoporous zinc oxide nanoparticles (ZnO NPs) and also to evaluate the cytotoxicity of mesoporous ZnO NPs on L929 mouse fibroblast cell lines using 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.

MATERIALS AND METHODS

The synthesized mesoporous ZnO NPs were extensively characterized using X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectra (EDAX), Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS). The cytotoxicity of mesoporous ZnO NPs was assessed by MTT assay. The study groups for cytotoxicity assay were normal saline, 0.1% calcined mesoporous ZnO NP solution, 1% calcined mesoporous ZnO NP solution, 0.1% noncalcined mesoporous ZnO NP solution, 1% noncalcined mesoporous ZnO NP solution, 0.1% ZnO NP solution, 1% ZnO NP solution, 2% chlorhexidine, and phosphate-buffered saline (PBS). The percentages of mean ± standard deviation of viable cells were analyzed.

RESULTS

Characterization of mesoporous ZnO NPs revealed that all the particles were in a more or less spherical shape with a wide particle size distribution of 70-100 nm. TEM image showed the uniformed and aggregated ZnO NPs with a typical size of 10-15 nm. BET analysis showed a mesoporous structure for the prepared mesoporous ZnO NPs. According to the MTT assay, chlorhexidine had the lowest cell viability percentage. Cell viability percentages of 0.1% mesoporous ZnO NP solutions (calcined and noncalcined) were statistically, significantly higher than 0.1% ZnO NP solution (p < .05). Cell viability percentages of 0.1% calcined and noncalcined mesoporous ZnO NP solutions and 0.1% ZnO NP solution were statistically, significantly higher than the 1% solutions (p < .05).

CONCLUSION

Mesoporous ZnO NPs exhibited less cytotoxicity against L929 mouse fibroblast cell lines compared to CHX and ZnO NPs, hence are safe to use.

A Mesostructure Multivariant-Assembly Reinforced Ultratough Biomimicking Superglue

The imitation of mussels and oysters to create high-performance adhesives is a cutting-edge field. The introduction of inorganic fillers is shown to significantly alter the adhesive's properties, yet the potential of mesoporous materials as fillers in adhesives is overlooked. In this study, the first report on the utilization of mesoporous materials in a biomimetic adhesive system is presented. Incorporating mesoporous silica nanoparticles (MSN) profoundly enhances the adhesion of pyrogallol (PG)-polyethylene imine (PEI) adhesive. As the MSN concentration increases, the adhesion strength to glass substrates undergoes an impressive fivefold improvement, reaching an outstanding 2.5 mPa. The adhesive forms an exceptionally strong bond, to the extent that the glass substrate fractures before joint failure. The comprehensive tests involving various polyphenols, polymers, and fillers reveal an intriguing phenomenon-the molecular structure of polyphenols significantly influences adhesive strength. Steric hindrance emerges as a crucial factor, regulating the balance between π-cation and charge interactions, which significantly impacts the multicomponent assembly of polyphenol-PEI-MSN and, consequently, adhesive strength. This groundbreaking research opens new avenues for the development of novel biomimetic materials.

Potential Applications and Additive Manufacturing Technology-Based Considerations of Mesoporous Silica: A Review

Nanoporous materials are categorized as microporous (pore sizes 0.2-2 nm), mesoporous (pore sizes 2-50 nm), and macroporous (pore sizes 50-1000 nm). Mesoporous silica (MS) has gained a significant interest due to its notable characteristics, including organized pore networks, specific surface areas, and the ability to be integrated in a variety of morphologies. Recently, MS has been widely accepted by range of manufacturer and as drug carrier. Moreover, silica nanoparticles containing mesopores, also known as mesoporous silica nanoparticles (MSNs), have attracted widespread attention in additive manufacturing (AM). AM commonly known as three-dimensional printing is the formalized rapid prototyping (RP) technology. AM techniques, in comparison to conventional methods, aid in reducing the necessity for tooling and allow versatility in product and design customization. There are generally several types of AM processes reported including VAT polymerization (VP), powder bed fusion (PBF), sheet lamination (SL), material extrusion (ME), binder jetting (BJ), direct energy deposition (DED), and material jetting (MJ). Furthermore, AM techniques are utilized in fabrication of various classified fields such as architectural modeling, fuel cell manufacturing, lightweight machines, medical, and fabrication of drug delivery systems. The review concisely elaborates on applications of mesoporous silica as versatile material in fabrication of various AM-based pharmaceutical products with an elaboration on various AM techniques to reduce the knowledge gap.

Design, Fabrication and Characterization of Multi-Yolk@Shell NiCuFe2 O4 @mSiO2 Mesoporous Nanocomposite Spheres for the Synthesis of Pyrimido-Quinolines under Solvent-Free Conditions

Multi-yolk@shell mesoporous silica spheres are becoming more and more attractive as high-performance catalysts because of their high surface areas, variable pore sizes, and low densities. In this work, a NiCuFe2 O4 magnetic core with a shell of mesoporous silica mesoporous has been prepared in an easy two-step procedure. The prepared multi-yolk@shell NiCuFe2 O4 @mSiO2 spheres were characterized by using FT-IR, XRD, VSM, EDX, BET, FE-SEM and HR-TEM techniques. These unique multi-yolk@shell NiCuFe2 O4 @mSiO2 spheres demonstrated high catalytic activity for the synthesis of pyrimidoquinolines. Also, this method exposes obvious benefits such as catalyst recyclability, easy reaction condition, simplicity of work up, high product yields and short reaction times.

Mesoporous Starch Cryoaerogel Material as an Emerging Platform for Oral Drug Delivery: Synthesis and In Vitro Evaluation

In this study, a starch cryoaerogel formulation was developed as a carrier for poorly water-soluble drugs, like atorvastatin. Cryoaerogels were generated through a sol-gel method combined with a freeze-drying technique, and atorvastatin was incorporated into the obtained mesoporous systems during the solvent exchange stage. The formulated drug-loaded polymer structures were characterized in terms of their physicochemical properties, solid-state behavior, and cytotoxicity. They had a pore size of 27.56 nm and a drug loading size of 38.60%. Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) analyses indicated that atorvastatin was successfully incorporated into the cryoaerogel pores. The amorphous nature of the loaded drug was confirmed via X-ray diffraction (XRD). Furthermore, after the atorvastatin incorporation into the cryogel, the volume of nitrogen adsorbed on one gram of cryoaerogel (Vm), as well as the specific surface area (aBET) were reduced. The comparison between the drug release profiles of crystalline atorvastatin and the loaded formulation of atorvastatin showed that by including the drug into the pores of the developed cryoaerogel matrix its solubility was significantly improved-the time for the dissolution of 30% pure atorvastatin (t30%) was approximately 4 h, whereas the determined t30% for the formulated cryoaerogels was only 1 h. Moreover, the data from the MTT assay illustrated that the designed cryoaerogel could be used as a safe oral atorvastatin delivery system. According to obtained results, it could be concluded that the starch cryoaerogel formulation is a promising candidate for oral delivery of poorly water-soluble therapeutic agents.

High-Performance Li-S Batteries with a Minimum Shuttle Effect: Disproportionation of Dissolved Polysulfide to Elemental Sulfur Catalyzed by a Bifunctional Carbon Host

A long cycle-life Li-S battery (both the coin cell and pouch cell) is reported with minimum shuttle effect. The performance was achieved with a bifunctional carbon material with three unique features. The carbon can catalyze the disproportionation of dissolved long-chain polysulfide ions to elemental sulfur; the carbon can ensure homogeneous precipitation of Li sulfide on the host carbon, and the carbon has a honeycomb porous structure, which can store sulfur better. All the features are demonstrated experimentally and reported in this paper. Few dissolved polysulfides are found by high-performance liquid chromatography in the electrolyte of the Li-S batteries during cycling, and only dissolved elemental sulfur is detected. The unique porous structure of the carbon made from raw silk is revealed by scanning electron microscopy. The N-containing functionalities that were introduced to carbon from the amino acids of raw silk can catalyze the disproportionation of the dissolved S_n^2- to solid S₈ at the cathode side, thereby mitigating the shuttle effect. In addition, the hierarchical honeycomb porous structures generated by a carbonization process can physically trap high-order lithium polysulfides and sustain the volume change of sulfur. With the synergistic effects of the unique structures and characteristics of the carbon prepared at 800 °C, the sulfur/carbon composite delivers a high reversible capacity of over 1000 mAh g^-1 after 100 cycles with a sulfur content of 1.2 mg cm^-2 in a pouch cell.

Effects of Mesoporosity and Conductivity of Hierarchically Porous Carbon Supports on the Deposition of Pt Nanoparticles and Their Performance as Electrocatalysts for Oxygen Reduction Reaction in Alkaline Media

The structural characteristics of supports, such as surface area and type of porosity, affect the deposition of electrocatalysts and greatly influence their electrochemical performance in fuel cells. In this work, we use a series of high surface area hierarchical porous carbons (HPCs) with defined mesoporosity as model supports to study the deposition mechanism of Pt nanoparticles. The resulting electrocatalysts are characterized by several analytical techniques, and their electrochemical performance is compared to a state-of-the-art, commercial Pt/C system. Despite the similar chemical composition and surface area of the supports, as well as similar amounts of Pt precursor used, the size of the deposited Pt nanoparticles varies, and it is inversely proportional to the mesopore size of the system. In addition, we show that an increase in the size of the catalyst particles can increase the specific activity of the oxygen reduction reaction. We also report on our efforts to improve the overall performance of the above electrocatalyst systems and show that increasing the electronic conductivity of the carbon support by the addition of highly conductive graphene sheets improves the overall performance of an alkaline fuel cell.

Selective Discrimination between CO and H2 with Copper-Ceria-Resistive Gas Sensors

The production of hydrogen and the utilization of biomass for sustainable concepts of energy conversion and storage require gas sensors that discriminate between hydrogen (H₂) and carbon monoxide (CO). Mesoporous copper-ceria (Cu-CeO₂) materials with large specific surface areas and uniform porosity are prepared by nanocasting, and their textural properties are characterized by N₂ physisorption, powder XRD, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The oxidation states of copper (Cu⁺, Cu²⁺) and cerium (Ce³⁺, Ce⁴⁺) are investigated by XPS. The materials are used as resistive gas sensors for H₂ and CO. The sensors show a stronger response to CO than to H₂ and low cross-sensitivity to humidity. Copper turns out to be a necessary component; copper-free ceria materials prepared by the same method show only poor sensing performance. By measuring both gases (CO and H₂) simultaneously, it is shown that this behavior can be utilized for selective sensing of CO in the presence of H₂.

High-Performance γ-Al2O3 Multichannel Tube-Type Tight Ultrafiltration Membrane Using a Modified Sol-Gel Method

We introduced a modified sol-gel method using polyvinyl alcohol (PVA) as an additive to improve the permeability of γ-Al₂O₃ membranes by minimizing the thickness of the selective layer and maximizing the porosity. First, the analysis revealed that the thickness of γ-Al₂O₃ decreased as the concentration of PVA increased in the boehmite sol. Second, the properties of the γ-Al₂O₃ mesoporous membranes were greatly influenced by the modified route (method B) compared to the conventional route (method A). The results showed that the porosity and surface area of the γ-Al₂O₃ membrane increased, and the tortuosity decreased considerably using method B. This effect was attributed to the adsorption of PVA molecules on the surface of the boehmite particles, which depended on the synthesis route. The experimentally determined pure water permeability trend and the Hagen-Poiseuille mathematical model confirmed that the modified method improved the performance of the γ-Al₂O₃ membrane. Finally, the γ-Al₂O₃ membrane fabricated via a modified sol-gel method with a pore size of 2.7 nm (MWCO = 5300 Da) exhibited a pure water permeability of over 18 LMH/bar, which is three times higher than that of the γ-Al₂O₃ membrane prepared using the conventional method.

In Situ Mesopore Formation in SiOx Nanoparticles by Chemically Reinforced Heterointerface and Use of Chemical Prelithiation for Highly Reversible Lithium-Ion Battery Anode

SiO_x is a promising next-generation anode material for lithium-ion batteries. However, its commercial adoption faces challenges such as low electrical conductivity, large volume expansion during cycling, and low initial Coulombic efficiency. Herein, to overcome these limitations, an eco-friendly in situ methodology for synthesizing carbon-containing mesoporous SiO_x nanoparticles wrapped in another carbon layers is developed. The chemical reactions of vinyl-terminated silanes are designed to be confined inside the cationic surfactant-derived emulsion droplets. The polyvinylpyrrolidone-based chemical functionalization of organically modified SiO₂ nanoparticles leads to excellent dispersion stability and allows for intact hybridization with graphene oxide sheets. The formation of a chemically reinforced heterointerface enables the spontaneous generation of mesopores inside the thermally reduced SiO_x nanoparticles. The resulting mesoporous SiO_x -based nanocomposite anodes exhibit superior cycling stability (≈100% after 500 cycles at 0.5 A g^-1 ) and rate capability (554 mAh g^-1 at 2 A g^-1 ), elucidating characteristic synergetic effects in mesoporous SiO_x -based nanocomposite anodes. The practical commercialization potential with a significant enhancement in initial Coulombic efficiency through a chemical prelithiation reaction is also presented. The full cell employing the prelithiated anode demonstrated more than 2 times higher Coulombic efficiency and discharge capacity compared to the full cell with a pristine anode.

Sol-Gel-Derived Ordered Mesoporous High Entropy Spinel Ferrites and Assessment of Their Photoelectrochemical and Electrocatalytic Water Splitting Performance

The novel material class of high entropy oxides with their unique and unexpected physicochemical properties is a candidate for energy applications. Herein, it is reported for the first time about the physico- and (photo-) electrochemical properties of ordered mesoporous (CoNiCuZnMg)Fe₂ O₄ thin films synthesized by a soft-templating and dip-coating approach. The A-site high entropy ferrites (HEF) are composed of periodically ordered mesopores building a highly accessible inorganic nanoarchitecture with large specific surface areas. The mesoporous spinel HEF thin films are found to be phase-pure and crack-free on the meso- and macroscale. The formation of the spinel structure hosting six distinct cations is verified by X-ray-based characterization techniques. Photoelectron spectroscopy gives insight into the chemical state of the implemented transition metals supporting the structural characterization data. Applied as photoanode for photoelectrochemical water splitting, the HEFs are photostable over several hours but show only low photoconductivity owing to fast surface recombination, as evidenced by intensity-modulated photocurrent spectroscopy. When applied as oxygen evolution reaction electrocatalyst, the HEF thin films possess overpotentials of 420 mV at 10 mA cm^-2 in 1 m KOH. The results imply that the increase of the compositional disorder enhances the electronic transport properties, which are beneficial for both energy applications.

Evaluation of drug release, monomer conversion and surface properties of resin composites containing chlorhexidine-loaded mesoporous and nonporous hydroxyapatite nanocarriers

The aim of this study was to evaluate drug release, degree of conversion (DC), and surface properties of resin composites containing chlorhexidine (CHX)-loaded mesoporous (mHAP) and nonporous hydroxyapatite (HAP) nanocarrier. CHX loaded mHAP and HAP, or CHX without nanocarrier was added into the resin composite in 1% and 5% concentrations. After characterization of experimental materials with XRD, EDX, FT-IR, and SEM, the CHX release on the 1st, 7th, 30th, and 120th days were evaluated by UV-vis spectroscopy. DC, surface roughness, and surface hardness of the samples were also evaluated. The data was statistically analyzed. While mHAP groups released significantly higher CHX on the 30th day (p < .05), there was no statistically significant difference between the HAP and mHAP groups on the 120th day (p > .05). DCs of all groups were similar (p > .05). While mHAP and HAP groups containing 5% CHX showed significantly higher roughness than the other groups (p < .05), no statistically significant difference was observed between the other groups (p > .05). The 1% and 5% CHX groups without nanocarrier showed significantly lower surface hardness (p < .05). However, no statistically significant difference was observed between the other groups in terms of surface hardness (p > .05). A controlled CHX release was achieved by mHAP and HAP nanocarriers for 120 days. The nanocarrier addition up to 5% did not negatively affect the DC and the surface hardness which is one of the surface properties of the resin composites. Although the addition of 5% nanocarrier to the resin composite increased the surface roughness, while adding 1% of these nanocarriers did not change.

Stimuli-Responsive Silica Silanol Conjugates: Strategic Nanoarchitectonics in Targeted Drug Delivery

The design of novel drug delivery systems is exceptionally critical in disease treatments. Among the existing drug delivery systems, mesoporous silica nanoparticles (MSNs) have shown profuse promise owing to their structural stability, tunable morphologies/sizes, and ability to load different payload chemistry. Significantly, the presence of surface silanol groups enables functionalization with relevant drugs, imaging, and targeting agents, promoting their utility and popularity among researchers. Stimuli-responsive silanol conjugates have been developed as a novel, more effective way to conjugate, deliver, and release therapeutic drugs on demand and precisely to the selected location. Therefore, it is urgent to summarize the current understanding and the surface silanols' role in making MSN a versatile drug delivery platform. This review provides an analytical understanding of the surface silanols, chemistry, identification methods, and their property-performance correlation. The chemistry involved in converting surface silanols to a stimuli-responsive silica delivery system by endogenous/exogenous stimuli, including pH, redox potential, temperature, and hypoxia, is discussed in depth. Different chemistries for converting surface silanols to stimuli-responsive bonds are discussed in the context of drug delivery. The critical discussion is culminated by outlining the challenges in identifying silanols' role and overcoming the limitations in synthesizing stimuli-responsive mesoporous silica-based drug delivery systems.

Layer-by-Layer Hollow Mesoporous Silica Nanoparticles with Tunable Degradation Profile

Silica nanoparticles (SNPs) have shown promise in biomedical applications such as drug delivery and imaging due to their versatile synthetic methods, tunable physicochemical properties, and ability to load both hydrophilic and hydrophobic cargo with high efficiency. To improve the utility of these nanostructures, there is a need to control the degradation profile relative to specific microenvironments. The design of such nanostructures for controlled combination drug delivery would benefit from minimizing degradation and cargo release in circulation while increasing intracellular biodegradation. Herein, we fabricated two types of layer-by-layer hollow mesoporous SNPs (HMSNPs) containing two and three layers with variations in disulfide precursor ratios. These disulfide bonds are redox-sensitive, resulting in a controllable degradation profile relative to the number of disulfide bonds present. Particles were characterized for morphology, size and size distribution, atomic composition, pore structure, and surface area. No difference was observed between in vitro cytotoxicity profiles of the fabricated nanoparticles at 24 h in the concentration range below 100 µg mL-1. The degradation profiles of particles were evaluated in simulated body fluid in the presence of glutathione. The results demonstrate that the composition and number of layers influence degradation rates, and particles containing a higher number of disulfide bridges were more responsive to enzymatic degradation. These results indicate the potential utility of layer-by-layer HMSNPs for delivery applications where tunable degradation is desired.

Electrochemical Synthesis, Magnetic and Optical Characterisation of FePd Dense and Mesoporous Nanowires

Dense and mesoporous FePd nanowires (NWs) with 45 to 60 at.% Pd content were successfully fabricated by template- and micelle-assisted pulsed potentiostatic electrodeposition using nanoporous anodic alumina and polycarbonate templates of varying pore sizes. An FePd electrolyte was utilized for obtaining dense NWs while a block copolymer, P-123, was added to this electrolyte as the micelle-forming surfactant to produce mesoporous NWs. The structural and magnetic properties of the NWs were investigated by electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The as-prepared NWs were single phase with a face-centered cubic structure exhibiting 3.1 µm to 7.1 µm of length. Mesoporous NWs revealed a core-shell structure where the porosity was only witnessed in the internal volume of the NW while the outer surface remained non-porous. Magnetic measurements revealed that the samples displayed a soft ferromagnetic behavior that depended on the shape anisotropy and the interwire dipolar interactions. The mesoporous core and dense shell structure of the NWs were seen to be slightly affecting the magnetic properties. Moreover, mesoporous NWs performed excellently as SERS substrates for the detection of 4,4'-bipyridine, showing a low detection limit of 10^-12 M. The signal enhancement can be attributed to the mesoporous morphology as well as the close proximity of the embedded NWs being conducive to localized surface plasmon resonance.

Heterostructured and Mesoporous Nb2O5@TiO2 Core-Shell Spheres as the Negative Electrode in Li-Ion Batteries

Niobium pentoxides have received considerable attention and are promising anode materials for lithium-ion batteries (LIBs), due to their fast Li storage kinetics and high capacity. However, their cycling stability and rate performance are still limited owing to their intrinsic insulating properties and structural degradation during charging and discharging. Herein, a series of mesoporous Nb₂O₅@TiO₂ core-shell spherical heterostructures have been prepared for the first time by a sol-gel method and investigated as anode materials in LIBs. Mesoporosity can provide numerous open and short pathways for Li⁺ diffusion; meanwhile, heterostructures can simultaneously enhance the electronic conductivity and thus improve the rate capability. The TiO₂ coating layer shows robust crystalline skeletons during repeated lithium insertion and extraction processes, retaining high structural integrity and, thereby, enhancing cycling stability. The electrochemical behavior is strongly dependent on the thickness of the TiO₂ layer. After optimization, a mesoporous Nb₂O₅@TiO₂ core-shell structure with a ∼13 nm thick TiO₂ layer delivers a high specific capacity of 136 mA h g^-1 at 5 A g^-1 and exceptional cycling stability (88.3% retention over 1000 cycles at 0.5 A g^-1). This work provides a facile strategy to obtain mesoporous Nb₂O₅@TiO₂ core-shell spherical structures and underlines the importance of structural engineering for improving the performance of battery materials.

Co Nanoparticles Confined in Mesoporous Mo/N Co-Doped Polyhedral Carbon Frameworks towards High-Efficiency Oxygen Reduction

Exploiting effective non-noble metal electrocatalysts for oxygen reduction reaction (ORR) is crucial for fuel cells and metal-air batteries. Herein, we designed and fabricated Co nanoparticles confined in Mo/N co-doped polyhedral carbon frameworks (Co-NP/MNCF) derived from polyoxometalate-encapsuled metal-organic framework, which showed comparable ORR performance with commercial Pt/C and a larger diffusion-limited current density. Moreover, the Co-NP/MNCF also exhibited excellent ORR stability and methanol tolerance. These appealing performances can be attributed to the porosity regulation and heteroatom doping of metal-organic framework derived polyhedral carbon frameworks, which could be beneficial for the exposure of more active sites, the optimization of electronic structure and the mass transfer of electrolyte/electron/ion.

The Ultrahigh Adsorption Capacity and Excellent Photocatalytic Degradation Activity of Mesoporous CuO with Novel Architecture

In this paper, mesoporous CuO with a novel architecture was synthesized through a conventional hydrothermal approach followed by a facile sintering procedure. HR-TEM analysis found that mesoporous CuO with an interconnected pore structure has exposed high-energy crystal planes of (002) and (200). Theoretical calculations indicated that the high-energy crystal planes have superior adsorption capacity for H⁺ ions, which is critical for the excellent adsorption and remarkable photocatalytic activity of the anionic dye. The adsorption capacity of CuO to methyl orange (MO) at 0.4 g/L was approximately 30% under adsorption equilibrium conditions. We propose a state-changing mechanism to analyze the synergy and mutual restraint relation among the catalyst CuO, H⁺ ions, dye and H₂O₂. According to this mechanism, the degradation rate of MO can be elevated 3.5 times only by regulating the MO ratio in three states.

Silica-based mesoporous ion-imprinted fluorescent sensors for the detection of Pb2+in aqueous environments

In this work, an environment-friendly core-shell material based on CDs@SiO₂as the core and mesoporous ion-imprinted layer as the shell was reported. As a highly sensitive and accurate fluorescent sensor for the detection of Pb²⁺in environmental water, the composition combined ion imprinting technology with quantum dots to selectively quench the fluorescence of CDs by metal coordination in the presence of Pb²⁺, and the visual change of gradually weakening blue color could be observed by the naked eye for visual detection. The mesoporous structure significantly improved the detection recognition rate of CDs@SiO₂@MIIPs.The molecularly imprinted sensor presented a favorable linear relationship over a Pb²⁺concentration range from 10 nmol l^-1to 100 nmol l^-1and a detection limit of 2.16 nmol l^-1for Pb²⁺. The imprinting factor of the CDs@SiO₂@MIIPs was 5.13. The sensor has a fast detection rate, is highly selective in the identification of Pb²⁺, and can be reused up to 10 times. The applicability of the method was evaluated by the determination of Pb²⁺in spiked environmental water samples with satisfactory results.

Comparative Studies of the Dielectric Properties of Polyester Imide Composite Membranes Containing Hydrophilic and Hydrophobic Mesoporous Silica Particles

In this paper, comparative studies of hydrophilic and hydrophobic mesoporous silica particles (MSPs) on the dielectric properties of their derivative polyester imide (PEI) composite membranes were investigated. A series of hydrophilic and hydrophobic MSPs were synthesized with the base-catalyzed sol-gel process of TEOS, MTMS, and APTES at a distinctive feeding ratio with a non-surfactant template of D-(-)-Fructose as the pore-forming agent. Subsequently, the MSPs were blended with the diamine of APAB, followed by introducing the dianhydride of TAHQ with mechanical stirring for 24 h. The obtained viscous solution was subsequently coated onto a copper foil, 36 μm in thickness, followed by performing thermal imidization at specifically programmed heating. The dielectric constant of the prepared membranes was found to show an obvious trend: PEI containing hydrophilic MSPs > PEI > PEI containing hydrophobic MSPs. Moreover, the higher the loading of hydrophilic MSPs, the higher the value of the dielectric constant and loss tangent. On the contrary, the higher the loading of hydrophobic MSPs, the lower the value of the dielectric constant with an almost unchanged loss tangent.

Enhanced Structural Control of Soft-Templated Mesoporous Inorganic Thin Films by Inert Processing Conditions

Mesoporous thin films are widely used for applications in need of high surface area and efficient mass and charge transport properties. A well-established fabrication process involves the supramolecular assembly of organic molecules (e.g., block copolymers and surfactants) with inorganic materials obtained by sol-gel chemistry. Typically, subsequent calcination in air removes the organic template and reveals the porous inorganic network. A significant challenge for such coatings is the anisotropic shrinkage due to the volume contraction related to solvent evaporation, inorganic condensation, and template removal, affecting the final porosity as well as pore shape, size, arrangement, and accessibility. Here, we show that a two-step calcination process, composed of high-temperature treatment in argon followed by air calcination, is an effective fabrication strategy to reduce film contraction and enhance structural control of mesoporous thin films. Crucially, the formation of a transient carbonaceous scaffold enables the inorganic matrix to fully condense before template removal. The resulting mesoporous films retain a higher porosity as well as bigger pores with extended porous order. Such films present favorable characteristics for mass transport of large molecules. This is demonstrated for lysozyme adsorption into the mesoporous thin films as an example of enzyme storage.

One-Pot Synthesis of Aminated Bimodal Mesoporous Silica Nanoparticles as Silver-Embedded Antibacterial Nanocarriers and CO2 Capture Sorbents

Mesoporous silica nanoparticles have highly versatile structural properties that are suitable for a plethora of applications including catalysis, separation, and nanotherapeutics. We report a one-pot synthesis strategy that generates bimodal mesoporous silica nanoparticles via coassembly of a structure-directing Gemini surfactant (C_16-3-16) with a tetraethoxysilane/(3-aminopropyl)triethoxysilane-derived sol additive. Synthesis temperature enables control of the nanoparticle shape, structure, and mesopore architecture. Variations of the aminosilane/alkylsilane molar ratio further enable programmable adjustments of hollow to core-shell and dense nanoparticle morphologies, bimodal pore sizes, and surface chemistries. The resulting Gemini-directed aminated mesoporous silica nanoparticles have excellent carbon dioxide adsorption capacities and antimicrobial properties against Escherichia coli. Our results provide an enhanced understanding of the structure formation of multiscale mesoporous inorganic materials that are desirable for numerous applications such as carbon sequestration, water remediation, and biomedical-related applications.

Preparation of multifunctional mesoporous SiO2nanoparticles and anti-tumor action

A targeted drug delivery system was developed to accumulate specific drugs around tumor cells based on the redox, temperature, and enzyme synergistic responses of mesoporous silica nanoparticles. Mesoporous silica nanoparticles (MSN-NH2) and Doxorubicin (DOX) for tumor therapy were prepared and loaded into the pores of MSN- NH2 to obtain DOX@MSN(DM NPs). Hyaluronic acid (HA) was used as the backbone and disulfide bond was used as the linker arm to graft carboxylated poly (N-isopropylacrylamide)(PNIPAAm-COOH) to synthesize the macromolecular copolymer (HA-SS-PNIPAAm), which was modified to DM NPs with capped ends to obtain the nano-delivery system DOX@MSN@HA-SS-PNIPAAm(DMHSP NPs), and a control formulation was prepared in a similar way. DMHSP NPs specifically entered tumor cells via CD44 receptor-mediated endocytosis; the high GSH concentration (10 mM) of cells severed the disulfide bonds, the hyaluronidase sheared the capped HA to open the pores, and increased tumor microenvironment temperature due to immune response can trigger the release of encapsulated drugs in thermosensitive materials.In vitroandin vivoantitumor and hemolysis assays showed that DMHSP NPs can accurately target hepatocellular carcinoma cells with a good safety profile and have synergistic effects, which meant DMHSP NPs had great potential for tumor therapy.

Camphene as a Mild, Bio-Derived Porogen for Near-Ambient Processing and 3D Printing of Porous Thermoplastics

Porous structures are ubiquitous in nature due to their advantageous mechanical and transport properties. These structures have inspired various synthetic porous polymer technologies, including lightweight structural materials and membranes. While many manufacturing processes have been developed to generate porous thermoplastics, these usually include hazardous processes, such as high pressures and temperatures, or chemical components. Furthermore, few are compatible with additive manufacturing methods, such as 3D printing. Herein, we introduce bio-derived terpene camphene as a solvent and porogen for the freeze-casting of thermoplastic parts under mild conditions. Enabled by a low melting point (50 °C), camphene is used as a solvent for melt processing camphene-polymer solutions at moderate temperatures that later undergo room-temperature crystallization to template polymer-rich domains. Due to its high vapor pressure, camphene can be sublimed directly from these biphasic structures, resulting in an interconnected microporous polymer structure. Various polymers are demonstrated to be soluble in camphene, including polystyrene, an olefinic elastomer, a polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene elastomer, a cyclic olefin copolymer, and poly(ethyl methacrylate). Porous samples of each polymer were generated from camphene mixtures via compression molding, cooling, and subsequent vacuum annealing at room temperature to remove camphene. The porosity and pore structures were dependent on solution composition, including both the polymer type and polymer loading. Across the compositions investigated, porosity decreased monotonically from 93 to 65% with increasing polymer content. In the case of polystyrene, samples with pore diameters varying from ∼20 to <5 μm were generated. Rheological measurements were conducted on a series of polystyrene-camphene solutions to understand and optimize the formulation and conditions for direct ink write 3D printing. Porous parts with complex structures were successfully printed under mild conditions. These results underscore the advantages of camphene as a sustainable, nontoxic porogen and will inform future development of porous polymer systems derived from these methods.

Sonochemically synthesized mesoporous cobalt oxide nanoparticles for luminol-enhanced chemiluminescence sensing

In recent years, mesoporous cobalt oxides have attracted more attention due to their exceptional physical and chemical properties and their important applications in various fields. The synthesis of cobalt oxides of various sizes, morphologies, and porosity is still a challenging process. In this report, mesoporous Co₃O₄NPs with different porosity were synthesized through facile, one-step, and cost-effective routes, without using any complicated materials or instruments, via the sonochemical process. X-ray powder diffraction (XRD), BET, and transmission electron microscopy (TEM) were used to characterize the as-synthesized NPs. XRD technique was used to determine the crystal structure and phase of the NPs, BET to describe the porous nature of the NPs, and TEM to investigate the structure and morphology of the NPs. Next, the effect of as-synthesized Co₃O₄NPs as a catalyst for the luminol-H₂O₂chemiluminescence system was studied. Co₃O₄NPs were chosen since they have nanoscale size, high specific surface area, and mesoporous nature. Therefore, these NPs can form more active sites and thus show unique catalytic activity than common ionic catalysts such as Co²⁺, Fe³⁺, Cu²⁺used in the luminol-H₂O₂CL system. Finally, this system was used to detect and measure H₂O₂and glucose under optimal conditions. A good linear relationship was observed between the chemiluminescence intensity of the designed system and the concentration of H₂O₂and glucose. A linear range like 0.25-10 pM for H₂O₂and 1-30 nM for glucose was obtained. The excellent LOD of the proposed method for measuring H₂O₂was about 0.07 pM, and for measuring glucose was about 0.14 nM.

One-Pot Synthesis of MnOx-SiO2 Porous Composites as Nanozymes with ROS-Scavenging Properties

The development of nanomaterials that mimic the activity of enzymes is a topic of interest, for the decomposition of reactive oxygen species (ROS). We report the preparation of a novel nanocomposite of MnO_x needles covered with SiO₂ porous material. The material was prepared in one pot with a two-step procedure. The material was characterized by EDX, SEM, TEM, XRD, nitrogen adsorption-desorption isotherms, and XPS. The synthesis protocol took advantage of the atrane method, favoring the nucleation and initial growth of manganese oxide needles that remained embedded and homogeneously dispersed in a mesoporous silica matrix. The final composite had a high concentration of Mn (Si/Mn molar ratio of ca. 1). The nanozyme presented bimodal porosity: intraparticle and interparticle association with the surfactant micelles and the gaps between silica particles and MnO_x needles, respectively. The porosity favored the migration of the reagent to the surface of the catalytic MnO_x. The nanozyme showed very efficient SOD and catalase activities, thus improving other materials previously described. The kinetics were studied in detail, and the reaction mechanisms were proposed. It was shown that silica does not play an innocent role in the case of catalase activity, increasing the reaction rate.

Metal Organic Framework-Derived ZnO@GC Nanoarchitecture as an Effective Hydrogen Gas Sensor with Improved Selectivity and Gas Response

Although they are not as favorable as other influential gas sensors, metal-oxide semiconductor-based chemiresistors ensure minimal surface reactivity, restricting their gas selectivity, gas response, and reaction kinetics, particularly when functioning at room temperature (RT). A hybrid design, which includes metal-oxide/carbon nanostructures and passivation with specific gas filtration layers, can address the concerns of surface reactivity. We present a novel hierarchical nanostructured zinc oxide (ZnO), decorated with graphitic carbon (GC) and synthesized via a wet-chemical strategy, which is then followed by the self-assembly of a zeolitic imidazolate framework (ZIF-8). Because of its large surface area, high porosity, and efficient inspection of other analyte (interfering) gases, the ZnO@GC can provide intensified surface reactivity at RT. In the present study, such a hybrid sensor confirmed extraordinary gas sensing properties, which was characterized by excellent H₂ selectivity, fast response, rapid recovery kinetics, and high gas response (ΔR/R₀ ∼ 124.6%@10 ppm), particularly in extremely humid environments. The results reveal that adsorption sites provided by the ZIF-8 template-based ZnO@GC frameworks facilitate the adsorption and desorption of H₂.

Rational Design of Mesoporous CuO-CeO2 Catalysts for NH3-SCR Applications Guided by Multiple In Situ Spectroscopies

Efficient nontoxic catalysts for low-temperature NH₃ selective catalytic reduction (NH₃-SCR) applications are of great interest. Owing to their promising redox and low-temperature activity, we prepared CuO-CeO₂ catalysts on a mesoporous SBA-15 support using targeted solid-state impregnation (SSI), guided by multiple in situ spectroscopy. The use of template P123 allowed dedicated modification of the surface properties of the SBA-15 matrix, resulting in a changed reactivity behavior of the metal precursors during the calcination process. To unravel the details of the transformation of the precursors to the final catalyst material, we applied in situ diffuse reflectance infrared Fourier transform (DRIFT), UV-visible (UV-vis), and Raman spectroscopies as well as online Fourier transform infrared (FTIR) monitoring of the gas-phase composition, in addition to ex situ surface, porosity, and structural analysis. The in situ analysis reveals two types of nitrate decomposition mechanisms: a nitrate-bridging route leading to the formation of a CuO-CeO₂ solid solution with increased low-temperature NH₃-SCR activity, and a hydrolysis route, which facilitates the formation of binary oxides CuO + CeO₂ showing activity over a broader temperature window peaking at higher temperatures. Our findings demonstrate that a detailed understanding of catalytic performance requires a profound knowledge of the calcination step and that the use of in situ analysis facilitates the rational design of catalytic properties.

Sorafenib tosylate incorporation into mesoporous starch xerogel for in-situ micronization and oral bioavailability enhancement

Poorly water-soluble drugs like sorafenib tosylate (SFB) can be made more soluble and orally bioavailable using a biocompatible hydrophilic matrix yields amorphous or microcrystalline drugs with high stability and low recrystallization risk. Mesoporous starch (MPS) due to its edibility, biodegradability, high surface area, and confined pores. In this study, MPS, either alone or in combination with polyvinylpyrrolidone (PVP), was employed for improving SFB oral bioavailability. To this aim, MPS was prepared in three steps: gelatinization, solvent exchange, and vacuum drying, after which it was used to incorporate SFB at various ratios using the immersion/solvent evaporation technique. Nitrogen adsorption/desorption analysis, Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) crystallography, and differential scanning calorimetry (DSC) were used to characterize SFB-loaded and drug-free samples, which confirmed the successful preparation of mesoporous structures with desirable uniform porosity, small pore size (about 5.3 nm), and specific surface area of about 24 m²/g. In-vitro dissolution testing revealed that the SFB dissolution rate increased substantially for the loaded MPS or MPS-PVP samples. Furthermore, when SFB was loaded in MPS-PVP, single-dose pharmacokinetics in rats confirmed an enhanced oral absorption kinetic. Therefore, impregnation of poorly soluble drugs such as SFB in the PVP-modified MPS excipient, which is constructed from a combination of mesoporous materials and a drug recrystallization inhibitor such as hydrophilic polymers, is proposed as a promising strategy for desirable enhancements in drug solubility, oral bioavailability, and efficacy.

Interface-Engineered Mesoporous with Programmed Drug Release for Synergistic Cancer Theranostics

The pursuit of mesoporous Fe-based nanoagents addresses the field of developing alternative Fe-bearing nanoagents for synergistic cancer therapy with the expectation that the use of an essential element may avoid the issues raised by the exogenous administration of other metal element-based nanoagents. Herein, we highlight the interface-engineered mesoporous FeB (mFeB) where the core mFeB is interfacially oxidized into an FeOOH nanosheet loaded with the chemotherapeutic drug doxorubicin (DOX) and further encapsuled within the double-sulfide-bonded SiO₂ outer layer, denoted as mFeB@DOX-ss-SiO₂, which can realize programmed drug release for synergistic cancer theranostics. When only in a tumor microenvironment, the nanoagent can be activated to release DOX from the mFeB and FeOOH nanosheets as well as expose the easily oxidized mFeB to spontaneously transform to FeOOH nanosheets with Fenton activity to facilitate chemodynamic therapy (CDT). In addition, the high photothermal conversion efficiency of mFeB@DOX-ss-SiO₂ would promote CDT. Also, owing to the inherent nature of ferromagnetism and red fluorescence of DOX, mFeB@DOX-ss-SiO₂ can realize T2-weighted magnetic resonance imaging and fluorescence imaging. In vivo mouse model experiments demonstrate that mFeB@DOX-ss-SiO₂ with good biocompatibility realizing CDT/photothermal therapy/chemotherapy achieved complete tumor suppression. This study opens up a new way to explore theranostic nanoagents.

Dynamic Intercalation-Conversion Site Supported Ultrathin 2D Mesoporous SnO2/SnSe2 Hybrid as Bifunctional Polysulfide Immobilizer and Lithium Regulator for Lithium-Sulfur Chemistry

The practical application of lithium-sulfur batteries is impeded by the polysulfide shuttling and interfacial instability of the metallic lithium anode. In this work, a twinborn ultrathin two-dimensional graphene-based mesoporous SnO₂/SnSe₂ hybrid (denoted as G-mSnO₂/SnSe₂) is constructed as a polysulfide immobilizer and lithium regulator for Li-S chemistry. The as-designed G-mSnO₂/SnSe₂ hybrid possesses high conductivity, strong chemical affinity (SnO₂), and a dynamic intercalation-conversion site (Li_xSnSe₂), inhibits shuttle behavior, provides rapid Li-intercalative transport kinetics, accelerates LiPS conversion, and decreases the decomposition energy barrier for Li₂S, which is evidenced by the ex situ XAS spectra, in situ Raman, in situ XRD, and DFT calculations. Moreover, the mesoporous G-mSnO₂/SnSe₂ with lithiophilic characteristics enables homogeneous Li-ion deposition and inhibits Li dendrite growth. Therefore, Li-S batteries with a G-mSnO₂/SnSe₂ separator achieve a favorable electrochemical performance, including high sulfur utilization (1544 mAh g^-1 at 0.2 C), high-rate capability (794 mAh g^-1 at 8 C), and long cycle life (extremely low attenuation rate of 0.0144% each cycle at 5 C over 2000 cycles). Encouragingly, a 1.6 g S/Ah-level pouch cell realizes a high energy density of up to 359 Wh kg^-1 under a lean E/S usage of 3.0 μL mg^-1. This work sheds light on the design roadmap for tackling S-cathode and Li-anode challenges simultaneously toward long-durability Li-S chemistry.

Impact of Copper-Doped Mesoporous Bioactive Glass Nanospheres on the Polymerisation Kinetics and Shrinkage Stress of Dental Resin Composites

We embedded copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) with antibacterial and ion-releasing properties into experimental dental composites and investigated the effect of Cu-MBGN on the polymerisation properties. We prepared seven composites with a BisGMA/TEGDMA (60/40) matrix and 65 wt.% total filler content, added Cu-MBGN or a combination of Cu-MBGN and silanised silica to the silanised barium glass base, and examined nine parameters: light transmittance, degree of conversion (DC), maximum polymerisation rate (R_max), time to reach R_max, linear shrinkage, shrinkage stress (PSS), maximum PSS rate, time to reach maximum PSS rate, and depth of cure. Cu-MBGN without silica accelerated polymerisation, reduced light transmission, and had the highest DC (58.8 ± 0.9%) and R_max (9.8 ± 0.2%/s), but lower shrinkage (3 ± 0.05%) and similar PSS (0.89 ± 0.07 MPa) versus the inert reference (0.83 ± 0.13 MPa). Combined Cu-MBGN and silica slowed the R_max and achieved a similar DC but resulted in higher shrinkage. However, using a combined 5 wt.% Cu-MBGN and silica, the PSS resembled that of the inert reference. The synergistic action of 5 wt.% Cu-MBGN and silanised silica in combination with silanised barium glass resulted in a material with the highest likelihood for dental applications in future.

High-Capacity Ti3C2Tx MXene Electrodes Achieved by Eliminating Intercalated Water Molecules Using a Co-solvent System

Synthesizing layered transition-metal carbides, MXenes, with a mesoporous structure remains challenging but is highly useful because it converts the laminated two-dimensional structures into versatile porous materials. Hydrogen bonds between intercalated H₂O molecules and oxygen terminal groups on the surface are formed in aqueous solution processes, and this is a determining factor of surface area. We developed an extraction method to remove intercalated water molecules based on a simple intermolecular force attraction strategy in a co-solvent system using a combination of polar-protic/-aprotic and non-polar solvents. As a result, self-aggregated mesoporous Ti₃C₂T_x was realized without any additives. The dipole-dipole interaction between H₂O and CHCl₃ molecules under non-polar solvent conditions assists the extraction of intercalated H₂O from the MXene suspension, which can form a self-aggregated morphology (not re-stacked horizontally). The process yields Ti₃C₂T_x with a layered structure of embedded mesopores and a specific surface area that is 13-fold higher than that of standard MXene. Electrodes made with the resulting MXene exhibited a larger specific capacitance of 224 F/g (1 A/g), with an improved cyclic retention of 96.4%@10,000 cycles. This intermolecular attraction-induced approach, involving the manipulation of morphology, is simple to mass-produce and can be used for MXene-based electrochemical applications.

A Novel Artificial Hemoglobin Carrier Based on Heulandite-Calcium Mesoporous Aluminosilicate Particles

Tetraethyl-orthosilicate (TEOS)-based nanoparticles are most extensively used as a silica-based hemoglobin carrier system. However, TEOS-based nanoparticles induce adverse effects on the hemoglobin structure. Therefore, a heulandite-calcium-based carrier was investigated as a novel silica-based hemoglobin carrier system. The heulandite-calcium mesoporous aluminosilicate particles (MSPs) were fabricated by a patented tribo-mechanical activation process, according to the manufacturer, and its structure was assessed by X-ray diffraction analysis. Upon hemoglobin encapsulation, alternation in the secondary and tertiary structure was observed. The hemoglobin-particle interactions do not cause heme degradation or decreased activity. Once encapsulated inside the particle pores, the hemoglobin shows increased thermal stability, and higher loading capacity per gram of particles (by a factor of >1.4) when compared to TEOS-based nanoparticles. Futhermore, we introduced a PEGlyted lipid bilayer which significantly decreases the premature hemoglobin release and increases the colloidal stability. The newly developed hemoglobin carrier shows no cytotoxicity to human umbilical vein endothelial cells (HUVEC).

Mesoporous NiCo2S4nanoflakes as an efficient and durable electrocatalyst for non-enzymatic detection of cholesterol

The detection of cholesterol is very crucial in clinical diagnosis for rapid and accurate monitoring of multiple disease-biomarkers. There is a great need for construction of a highly reliable and stable electrocatalyst for the efficient detection of cholesterol. In this work, mesoporous NiCo₂S₄nanoflakes of enhanced electrochemical properties are prepared through a facile hydrothermal approach. The developed nanoflakes modified nickel foam electrode exhibits outstanding electrocatalytic properties for the detection of cholesterol with high selectivity. The electrode displays excellent sensitivity of 8623.6μA mM^-1cm^-2, in the wide linear range from 0.01 to 0.25 mM with a low detection limit of 0.01μM. In addition, NiCo₂S₄structure reveals good thermal stability and reproducibility over a period of 8 weeks. Moreover, the nanoflakes show good response for detection of cholesterol in real samples. Our results demonstrate the potential use of NiCo₂S₄as a catalyst for the development of cost-effective electrochemical sensors for medical and industrial applications.

Synthesis and Characterization of Mesoporous Aluminum Silicate and Its Adsorption for Pb (II) Ions and Methylene Blue in Aqueous Solution

Aluminum silicate powder was prepared using two different syntheses: (1) co-precipitation and (2) two-step sol-gel method. All synthesized powders were characterized by various techniques including XRD, FE-SEM, FT-IR, BET, porosimeter, and zetasizer. The particle morphology of the synthesized aluminum silicate powder was greatly different depending on the synthesis. The synthesized aluminum silicate powder by co-precipitation had a low specific surface area (158 m²/g) and the particle appeared to have a sharp edge, as though in a glassy state. On the other hand, synthesized aluminum silicate powder by the two-step sol-gel method had a mesoporous structure and a large specific surface area (430 m²/g). The aluminum silicate powders as adsorbents were characterized for their adsorption behavior towards Pb (II) ions and methylene blue in an aqueous solution performed in a batch adsorption experiment. The maximum adsorption capacities of Pb (II) ions and methylene blue onto the two-step sol-gel method powder were over four-times and seven-times higher than that of the co-precipitation powder, respectively. These results show that the aluminum silicate powder synthesized with a two-step sol-gel method using ammonia can be a potential adsorbent for removing heavy metal ions and organic dyes from an aqueous solution.

Ordered Mesoporous Boron Carbon Nitrides with Tunable Mesopore Nanoarchitectonics for Energy Storage and CO2 Adsorption Properties

Porous boron carbon nitride (BCN) is one of the exciting systems with unique electrochemical and adsorption properties. However, the synthesis of low-cost and porous BCN with tunable porosity is challenging, limiting its full potential in a variety of applications. Herein, the preparation of well-defined mesoporous boron carbon nitride (MBCN) with high specific surface area, tunable pores, and nitrogen contents is demonstrated through a simple integration of chemical polymerization of readily available sucrose and borane ammonia complex (BAC) through the nano-hard-templating approach. The bimodal pores are introduced in MBCN by controlling the self-organization of BAC and sucrose molecules within the nanochannels of the template. It is found that the optimized sample shows a high specific capacitance (296 F g^-1 at 0.5 A g^-1 ), large specific capacity for sodium-ion battery (349 mAg h^-1 at 50 mAh g^-1 ), and excellent CO₂ adsorption capacity (27.14 mmol g^-1 at 30 bar). Density functional theory calculations demonstrate that different adsorption sites (BC, BN, CN, and CC) and the large specific surface area strongly support the high adsorption capacity. This finding offers an innovative breakthrough in the design and development of MBCN nanostructures for energy storage and carbon capture applications.

Mesoporous Silk-Bioactive Glass Nanocomposites as Drug Eluting Multifunctional Conformal Coatings for Improving Osseointegration and Bactericidal Properties of Metal Implants

Endowing metal implants with multifunctional traits to prevent implant-associated infections and improve osseointegration has become a pivotal facet in orthopedics and dental fixation. Herein, we report the synthesis of mesoporous 70S bioactive glass-silk fibroin nanocomposites inspired by the biomimetic organo-apatites of mineralized collagen. The mesoporous, biomimetic nanocomposites enabled loading of antibiotics (gentamicin and doxycycline) and favored their release in a rapid manner while preserving their bioactivity. Ease in modification of the mesoporous nanocomposites enabled tailoring of 3-(aminopropyl)-triethoxysilane to the silanol network of bioactive glass, which improved the loading capacity of the hydrophobic drug (dexamethasone). The modification favored the slow and sustained release of dexamethasone from the modified mesoporous nanocomposites, which is desired for mediating osteogenesis and immunomodulation. Conformal coatings of these drug-loaded nanocomposites were materialized on stainless-steel implants through a facile electrophoretic deposition (EPD) technique, wherein the deposition yield can be controlled by applied parameters. Antibiotic coatings exhibited antibacterial efficacy with bioactivity retained up to 28 days, while dexamethasone-loaded coatings favored mesenchymal stem cell adhesion and osteoinduction. The immunomodulatory roles were also ascertained, wherein M2 macrophage biasness was favored in dexamethasone-loaded coatings. The versatility of these mesoporous biomimetic nanocomposites guarantee the loading of scenario-specific drugs to aid their local delivery through the conformal EPD coatings developed over metal implants toward improving implant patency.

Constructing Polyimide Aerogels with Carboxyl for CO2 Adsorption

In this study, mesoporous polyimide aerogels with carboxyl were successfully synthesized by the co-polymerization method at room temperature from pyromellitic dianhydride and 1,3,5-triaminophenoxybenzene, 3,5-diaminobenzoic acid, and 2,2′-dimethyl-4,4′-diaminobiphenyl. Compared to previously reported porous organic polymer materials, this aerogel has the advantage of a simple and efficient synthesis method. The thermal decomposition temperatures of the obtained polyimide aerogels are all above 400 °C and have excellent thermal stability. Among them, the largest specific surface area is 62.03 m²/g. Although the surface area of this aerogel is not large enough, it has considerable CO₂ adsorption properties. The adsorption capacity of CO₂ is up to 11.9 cm³/g, which is comparable to those of previously reported porous materials. The high CO₂ adsorption is attributed to the abundance of carboxyl groups in the polyimide networks. The mild and convenient synthesis method and high CO₂ adsorption capacity indicate that the polyimide aerogel with carboxyl is suitable as a good candidate material for CO₂ adsorption.

Spray Deposition Synthesis of Locally Ordered Mesoporous Polycrystalline Titania Films at Low Temperature

A low-temperature spray deposition synthesis was developed to prepare locally hexagonally ordered mesoporous titania films with polycrystalline anatase pore walls in an evaporation-induced self-assembly process. The titania film preparation procedure is conducted completely at temperatures below 50 °C. The effects of spray time, film thickness, synthesis time prior to spray deposition, and aging time at high relative humidity after deposition on the atomic arrangement and the mesoorder of the mesoporous titania were studied. We find the crystallite size to depend on both the synthesis time and aging time of the films, where longer times result in larger crystallites. Using the photocatalytic activity of titania, the structure-directing agent is removed with UV radiation at 43-46 °C. The capability of the prepared films to remove the polymer template increased with longer synthesis and aging times due to the increased crystallinity, which increases the photocatalytic efficiency of the titania films. However, with increasingly longer times, the crystallites grow too large for the mesoorder of the pores to be maintained. This work shows that a scalable spray coating method can be used to prepare locally ordered mesoporous polycrystalline titania films by judiciously tuning the synthesis parameters.

Interfacial Assembly of Nanowire Arrays toward Carbonaceous Mesoporous Nanorods and Superstructures

Synthesis of anisotropic carbonaceous nano- and micro-materials with well-ordered mesoporous structures has attracted increasing attention for a broad scope of applications. Although hard-templating method has been widely employed, overcoming the viscous forces to prepare anisotropic mesoporous materials is particularly challenging via the universal soft-templating method, especially from sustainable biomass as a carbon resource. Herein, the synthesis of biomass-derived nanowire-arrays based mesoporous nanorods and teeth-like superstructures is reported, through a simple and straightforward polyelectrolyte assisted soft-templating hydrothermal carbonization (HTC) approach. A surface energy induced interfacial assembly mechanism with the synergetic interactions between micelles, nanowire, nanorods, and polyelectrolyte is proposed. The polyelectrolyte acts not only as a stabilizer to decrease the surface energy of cylindrical micelles, nanowires and nanorods, but also as a structure-directing agent to regulate the oriented attachment and anisotropic assembly of micelles, nanowires, and nanorods. After a calcination treatment, the carbon nanorod and teeth-like superstructure are successfully coupled with Ru to directly produce supported catalysts for the hydrogen evolution reaction, exhibiting much better performance than the isotropic nanospheres based catalyst. This HTC approach will open up new avenues for the synthesis of anisotropic materials with various morphologies and dimensions, expanding the palette of materials selection for many applications.

Mesoporous SBA-15 Silica-Loaded Nano-formulation of Quercetin: A Probable Radio-Sensitizer for Lung Carcinoma

Lung cancer is considered as one of the most serious disease worldwide. The progress of drug carriers based on nonmaterial, which selectively hold chemotherapeutic agents to cancer cells, has become a major focus in biomedical research. This study aimed to evaluate the growth inhibition and apoptosis induction of the human lung cancer cells (A-549) by Q-loaded SBA-15 conjugate system. Mesoporous silica nanoparticles (SBA-15) as host materials for transporting therapeutics medicaments were fabricated for targeted drug delivery toward lung cancer. With the objective of increasing bioavailability and aqueous solubility of flavonoids, SBA-15 was successfully loaded with the quercetin (Q)-a major flavonoid and characterized with the help of Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The biological investigation on A549 cell line confirmed that the efficacy of Q-SBA-15 is much higher than only Q. Moreover, the apoptotic pathway of synthesized Q-SBA-15 NPs examined that the Q-SBA-15-mediated apoptosis via PI3K/AKT/mTOR signaling pathway. Thus, the newly conjugated Q-SBA-15 system improved the apoptotic fate through caspase-mediated apoptosis via PI3K/AKT/mTOR signaling pathway and hence, it can be potentially employed as an anticancer agent for lung cancer.

A Comprehensive Review of Synthesis, Applications and Future Prospects for Silica Nanoparticles (SNPs)

Silica nanoparticles (SNPs) have shown great applicability potential in a number of fields like chemical, biomedical, biotechnology, agriculture, environmental remediation and even wastewater purification. With remarkably instinctive properties like mesoporous structure, high surface area, tunable pore size/diameter, biocompatibility, modifiability and polymeric hybridizability, the SNPs are growing in their applicable potential even further. These particles are shown to be non-toxic in nature, hence safe to be used in biomedical research. Moreover, the molecular mobilizability onto the internal and external surface of the particles makes them excellent carriers for biotic and non-biotic compounds. In this respect, the present study comprehensively reviews the most important and recent applications of SNPs in a number of fields along with synthetic approaches. Moreover, despite versatile contributions, the applicable potential of SNPs is still a tip of the iceberg waiting to be exploited more, hence, the last section of the review presents the future prospects containing only few of the many gaps/research extensions regarding SNPs that need to be addressed in future work.

Solid Oxide Cell Electrode Nanocomposites Fabricated by Inkjet Printing Infiltration of Ceria Scaffolds

The enhancement of solid oxide cell (SOC) oxygen electrode performance through the generation of nanocomposite electrodes via infiltration using wet-chemistry processes has been widely studied in recent years. An efficient oxygen electrode consists of a porous backbone and an active catalyst, which should provide ionic conductivity, high catalytic activity and electronic conductivity. Inkjet printing is a versatile additive manufacturing technique, which can be used for reliable and homogeneous functionalization of SOC electrodes via infiltration for either small- or large-area devices. In this study, we implemented the utilization of an inkjet printer for the automatic functionalization of different gadolinium-doped ceria scaffolds, via infiltration with ethanol:water-based La_1−xSr_xCo_1−yFe_yO_3−δ (LSCF) ink. Scaffolds based on commercial and mesoporous Gd-doped ceria (CGO) powders were used to demonstrate the versatility of inkjet printing as an infiltration technique. Using yttrium-stabilized zirconia (YSZ) commercial electrolytes, symmetrical LSCF/LSCF–CGO/YSZ/LSCF–CGO/LSCF cells were fabricated via infiltration and characterized by SEM-EDX, XRD and EIS. Microstructural analysis demonstrated the feasibility and reproducibility of the process. Electrochemical characterization lead to an ASR value of ≈1.2 Ω cm² at 750 °C, in the case of nanosized rare earth-doped ceria scaffolds, with the electrode contributing ≈0.18 Ω cm². These results demonstrate the feasibility of inkjet printing as an infiltration technique for SOC fabrication.