Inorganic Mesoporous Materials Research Articles

Crosslinking ionic oligomers sol-gel synthesis of high-surface-area mesoporous magnesium carbonate and its general applicability

Mesoporous magnesium carbonate has been widely used in controlled release of drugs, adsorption or catalysis. In traditional methods, expensive alkoxide or MgO are usually employed as Mg-source to prepare mesoporous magnesium carbonate. Herein, based on the crosslinking property of ionic oligomers, a novel crosslinking ionic oligomer sol-gel method was proposed to prepare high-surface-area mesoporous magnesium carbonate using cheap MgCl2·6H2O and CO2 as material. (MgCO3)n crosslinking oligomer sols was produced based on the H-bond capping effects of ethanol and triethylamine. The evolution mechanism of crosslinking (MgCO3)n oligomer sols to gels was studied by using ATR-FTIR and NMR. The results indicated that with the slow volatilization of ethanol and triethylamine, a part of H-bond disappeared, which initiating the chain growth of (MgCO3)n oligomer molecules, and finally forming a crosslinking network. Combined with a CO2 critical point drying process, amorphous mesoporous magnesium carbonate nanoparticle with high surface area was obtained and characterized using ATR-FTIR, XRD, XPS, nitrogen adsorption/desorption analysis, SEM, TEM and EDS systematically. The specific surface area of magnesium carbonate reached 628 m2 g−1 when the n(TEA)/n(Mg2+) was 40:1. Moreover, the general applicability of this method was verified. Mesoporous sulfate and phosphate were synthesized, which indicating the crosslinking oligomer sol-gel chemistry provided a general strategy for the construction of mesoporous inorganic oxysalt materials. Our work has important guiding significance for the preparation of other mesoporous materials that using cheap inorganic salt as raw material.

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 (C16-3-16) 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.

Integrated Process for Structuring and Functionalizing Ordered Mesoporous Silica to Achieve Superprotonic Conductivity

Polyacid-functionalized inorganic mesoporous materials have attracted considerable interest as catalysts, permselective molecular sieves, or drug carriers. Despite the great interest, their synthesis into ordered mesostructures incorporating polyacids densely and homogeneously distributed in the mesopores is a challenge. Moreover, their properties as conductors for energy applications remain completely unexplored. Here, we report an efficient, one-shot environmentally friendly synthesis route to prepare ordered mesoporous silica functionalized with strong polyacids, which exhibits excellent proton conductivity. We used polyion electrostatic complex micelles as structure-directing, functionalizing, and pore-generating agents to obtain a material of remarkable textural and functional quality. It presents large and ordered mesopores hosting monodisperse polyacid chains corresponding to a dense and homogeneous functionalization of 1.2 mmolSO3H gSiO2–1 and a function density of 1 SO3H per nm3 of mesopore volume. Overcoming the performance-limiting inhomogeneities, we designed a superprotonic conductor, while the high value of the conductivity, 0.024 S cm–1 at 363 K/95% relative humidity, was maintained for at least 7 days.

Seamless route of self-assembly and 3D printing to fabricate hierarchical mesoporous bioactive glass scaffold for customized bone regeneration with enhanced efficacy

Mesoporous bioactive glass (MBG) was one of the most promising bone regenerative materials for its well-acknowledged bioactivity, biodegradability, and osteoinductivity, as well as its potential for drug delivery. However, it remained a challenge to fabricate MBG scaffold with precisely controllable macro-structure and robust mechanical strength meanwhile to maintain uncompromised composition and mesoporosity. Herein, a fabricating route incorporating self-assembly and 3D printing (SAP) via acryloylating F127 (mesoporous template) was proposed and successfully realized directly printing MBG sol into hierarchical macro-/mesoporous SAP-MBG scaffold with compact and integral structure. Compared to traditional polyurethane (PU) templated MBG scaffold, SAP-MBG scaffold exhibited significantly enhanced mechanical strength meanwhile maintained non-composite component and mesoporous structure. SAP-MBG presented improved macropore interconnectivity and faster calcium dissolution, resulting in superior cellular penetration, in vitro osteogenic performances and in vivo bone regenerative efficacy in a critical-size rat cranial defect model. The SAP fabricating route represented an available approach to overcome the drawbacks of conventional manufacturing methods and realized individualized manufacturing of MBG scaffold. The synthetic design of this study might be extended to the fabricating process improvement of other mesoporous inorganic materials and shed light on future clinical translation of MBG scaffold in bone regeneration.

Weak-solvent-modulated optical encryption based on perovskite nanocrystals/polymer composites

Smart perovskite-based stimulus-responsive fluorescent materials have attracted considerable attention for confidential information protection, are mostly encapsulated in inorganic mesoporous materials, while little in easily processed polymers. Polymers, despite providing ultra-high resistance to humidity, heat and solvents, inevitably restrict the intrusion of external stimulation sources. In this study, based on perovskite nanocrystals/polymer composites, a weak solvent engineering strategy is rationally designed within the inaugural application in the encryption and decryption of confidential information. N,N-dimethylformamide and water are blended as weak solvents, which can swell and penetrate the polymer after spraying. This triggers the fluorescence quenching effect of the polar solvent on the encapsulated perovskite quantum dots and realizes information encryption. Recrystallization of perovskite can be easily achieved by high-temperature treatment to remove weak solvents, and hence regain its fluorescence properties. By introducing and removing the weak solvent, the perovskite-based composite can be quenched and restored, which enables reversible switching of the fluorescence signal. Surprisingly, the switch is highly effective in encrypting and decrypting various types of information. The optical encryption strategy via weak solvent modification not only provides a new path toward information security transmission but also, with its design friendliness, will contribute to the development and design of myriad innovations for data protection.

Adsorption of Dibenzothiophene in Gasoline by Si-MCM-41/Sodium Alginate Porous Hybrid Membrane

In this paper, the novel Si-MCM-41/SA porous hybrid membrane was prepared by in-corporating inorganic mesoporous material Si-MCM-41 into sodium alginate (SA) matrix, then cross-linking with 5% glutaraldehyde and 1.0 mol/L hydrochloric acid. Using scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and atomic force microscope (AFM), the prepared Si-MCM-41 sample and Si-MCM-41/SA porous hybrid membrane were characterized. The adsorption kinetics of the dibenzothiophene (DBT) by the Si-MCM-41/SA porous hybrid membrane was explored. Meanwhile, the effects of Si-MCM-41 content, porogen addition amount, DBT concentration, solution temperature, toluene concentration and other factors on the adsorption property of the Si-MCM-41/SA porous hybrid membrane were studied. In addition, the selectivity and reusability of the Si-MCM-41/SA porous hybrid membrane were also explored. The results show that the Si-MCM-41/SA porous hybrid membrane has excellent adsorption capacity for DBT, reaching 350.74 mg/g, which is a great improvement over the pure SA membrane. Moreover, among three sulfides of thiophene, 3-methylthiophene and DBT, the Si-MCM-41/SA porous hybrid membrane has the highest adsorption selectivity for DBT. The Si-MCM-41/SA porous hybrid membrane can be reused at least 5 times. Therefore, it can be known that the Si-MCM-41/SA porous hybrid membrane is an ideal adsorption material with practical application prospects.

Study on adenosine loading capacity of porous nanosilica for application in drug delivery

Mesoporous silica nanoparticles (MSNs) are used as drug delivery materials because of their outstanding features such as large surface area, easy synthesis and high biocompability. In this study, inorganic mesoporous nanosilica material, MCM-41, was synthesized by sol-gel hydrothermal method using tetraethyl orthosilicate precursor (TEOS). The material structure and composition were analyzed by X-ray power diffraction (P-XRD), N2 adsorption isotherm, thermalgravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FT-IR). Its morphology was examined by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results showed that synthesized MCM-41 has a spherical shape, homogeneous with an average size of 100 nm. The specific surface area is 845 m2 g􀀀1, the pore size is approximately 35 Å. It has high thermal stability until 800oC. FT-IR result showed the formation of the Si-O-Si bond in the structure. The adenosine loading capacity of MCM-41 was investigated based on the influence of loading factors including adenosine concentration, time, solvent, and temperature. The kinetics and thermodynamics of the adsorption processes were also studied. The adenosine loading ability on MCM-41 is significant high, approximately 1699 mg g􀀀1. The kinetic and thermodynamic results showed that the drug adsorbed of MCM-41 occurred with fast rate and spontaneously. Moreover, the release profile of adenosine proved that the drug release process occurred quickly which is suitable for application in acute disease treatment.

Surface molecular design of organic–inorganic mesoporous hybrid materials for CO2 capture

In the present work, a series of organic–inorganic hybrids was designed by using different solvents on 3-aminopropyltriethoxysilane (APTS) grafting on SBA-15. Different characterization techniques were used to evaluate how distinct solvents drive the surface architecture, amine loading, APTS-SBA-15 linkage configuration, surface area and pore volume. FT-IR and 29Si MAS NMR confirmed APTS grafting on SBA-15 surface. Elemental analysis showed that N loading varied from 2.09% up to 5.21%, while the range of C/N ratios (2.69–4.34) indicated that the number of bonds formed between APTS and SBA-15 (linkage configuration) remained between 2 (C/N = 4.3) and 3 (C/N = 2.6). N2 physisorption and TGA data showed that textural properties and APTS content on the synthesized materials were simultaneously dependent on N loading and linkage configuration. The presented data showed that the hybrids properties can be correlated with the solvent polarity, more specifically with the interaction between the inorganic matrix surface and the solvent during grafting. A new approach was presented using the solvent eluent strength to rationalize such correlation. Among all tested solvents, cyclohexane rendered the adsorbent with the highest N loading (5.21%) and more stable linkage configuration (C/N = 4.34). CO2 capture tests showed that the increase of amine loading and surface density improves not only the hybrid capacity to chemisorb CO2, but also its adsorption efficiency. CO2 capture capacities varied from 25 up to 516 µmol CO2 g−1. The correlation between adsorption capacity and N content for the synthesized APTS-SBA-15 hybrids was best fitted by a power function.

Mesoporous zirconia nanoparticles as drug delivery systems: Drug loading, stability and release

Drug delivery systems have been a milestone in medical research in the last twenty years, still representing a key aspect of innovation and evolution in pharmacokinetics and pharmacodynamics. Among several proposed solutions, inorganic mesoporous materials could be a promising vehicle. Their specific chemical-physical properties make them ideal candidates for the adsorption and loading of active pharmaceutical ingredients (API). Recently, mesoporous zirconia nanoparticles (MZNs) have been described as a novel drug delivery system due to their high surface area and biocompatibility. In this work, we investigated the loading and release efficiencies of a wide range of API on MZNs characterized by suitable pore volume and versatility, focusing on the integrity of the released drugs investigated through solution NMR and ESI-MS techniques. In order to explore the potentialities of MZNs for biomedical applications, we selected ibuprofen, N-acetyl-l-cysteine, vancomycin, gentamicin, nitrofurantoin, and indomethacin as benchmark API characterized by a wide range of polarity, molecular weight and presence of different functional groups. MZNs showed to efficiently load and release most of the API investigated. Long time loadings were also investigated observing that, after more than three months, no side reaction occurred on the released drugs except for intrinsically more labile API like NTF and NAC. MZNs ensured high inertness towards a wide range of functional groups such as aliphatic and aromatic amides, acetals of sugar residues as well as several chiral moieties bearing tertiary stereocenters.

Polymer blend directed anisotropic self-assembly toward mesoporous inorganic bowls and nanosheets.

Anisotropic mesoporous inorganic materials have attracted great interest due to their unique and intriguing properties, yet their controllable synthesis still remains a great challenge. Here, we develop a simple synthesis approach toward mesoporous inorganic bowls and two-dimensional (2D) nanosheets by combining block copolymer (BCP)-directed self-assembly with asymmetric phase migration in ternary-phase blends. The homogeneous blend solution spontaneously self-assembles to anisotropically stacked hybrids as the solvent evaporates. Two minor phases-BCP/inorganic precursor and homopolystyrene (hPS)-form closely stacked, Janus domains that are dispersed/confined in the major homopoly(methyl methacrylate) (hPMMA) matrix. hPS phases are partially covered by BCP-rich phases, where ordered mesostructures develop. With increasing the relative amount of hPS, the anisotropic shape evolves from bowls to 2D nanosheets. Benefiting from the unique bowl-like morphology, the resulting transition metal oxides show promise as high-performance anodes in potassium-ion batteries.

Phosphorus‐Modified Mesoporous Inorganic Materials for Production of Hydrocarbon Fuels and Value‐Added Chemicals

AbstractPhosphorus‐modified mesoporous inorganic materials play crucial roles in the valorization of lignocellulosic biomass materials such as syngas (CO and H2), carbohydrate sugars and lignin. This review summarizes the recent advances on the Co‐impregnated phosphorus‐modified γ‐Al2O3 and SiO2 catalysts for production of liquid hydrocarbon fuels via Fischer‐Tropsch synthesis (FTS) reaction of syngas as well as metal phosphates or precious (Pt and Ru) metals‐supported on the metal phosphates for production of furanic compounds, levulinic acid, aromatics and fuel commodities from carbohydrate sugars and lignin. These phosphorus‐modified materials play key roles in the syngas as well as biomass conversion processes due to their tunable surface properties and mesoporous structures. Phosphorus to metal ratios of inorganic materials with their porosity, calcination temperatures of metal phosphates, natures of biomass feedstocks, and reaction variables significantly affect yields of both hydrocarbon fuels and value‐added chemicals. This short review mainly focusses on the various applications of those mesoporous catalysts and supports, and strategies for effective catalytic transformations of lignocellulosic biomass‐derived feedstocks.

Chiral Inorganic mesoporous materials used as the stationary phase in GC

AbstractMesoporous materials are promising functional materials due to their properties, such as a large surface area, tunable pore size, structure and morphology. Chiral mesoporous silica is an indispensable part of mesoporous materials. Considering that chirality is rare in inorganic mesoporous materials, there are very few reports on chiral inorganic mesoporous silica for chromatographic separations. In this work, we report the use of chiral inorganic mesoporous silica based on the template of myristyl chloride‐l‐valine sodium as the stationary phase for enantioselective separation in gas chromatography. Thirteen chiral compounds were resolved on a fabricated column using dynamic coating, including chiral alcohols, epoxides and amino acid derivatives. In addition, n‐alkanes, n‐alcohols and aromatic hydrocarbons have also been separated.

Immobilization of Recombinant Endo‐1,4‐β‐xylanase on Ordered Mesoporous Matrices for Xylooligosaccharides Production

AbstractXylooligosaccharides (XOS) are emerging prebiotics, widely used in food, medicine and health care. XOS are produced by hydrolysis of xylan by acid or endoxylanase enzyme. Xylanase hydrolysis is preferred over acid due to its high specificity and absence of formation of non‐toxic byproducts. Immobilized xylanase improves enzyme‐stability and efficacy of XOS production through its repeated use. Though there are a few xylanases immobilized on conventional organic polymers for XOS production, immobilization of xylanse on mesoporous inorganic materials have not been investigated for XOS production. In this study, the recombinant endo‐1, 4‐β‐D‐xylanase (XynC) of B.subtilis KCX006 was purified and immobilized on ordered mesoporous matrices of carbon (CMK‐3), silica (SBA‐15) and zirconia (ZMF‐127). The immobilized‐XynC was characterized and used for XOS production by recycling. The recovered activity (RA) of immobilized‐XynC varied between 55 to 84%. The maximum RA was observed for XynC immobilized on ZMF‐127 matrix. All immobilized‐XynC had optimum pH similar to that of free‐XynC. But all immobilized‐XynC gained broader temperature range (50‐65°C) for optimal catalytic activity when compared with the free‐XynC. Immobilization of XynC resulted in higher Km due to substrate diffusion limit. All immobilized‐XynC produced free‐XOS of DP 2–6 (X2‐X6) and substituted‐XOS from beechwood xylan and extracted crude xylans from sorghum stalks and sugarcane bagasse (SCB). The XynC immobilized on SBA‐15 produced higher proportions of X2‐X6 compared to ZMF‐127 and CMK‐3. The XynC immobilized on SBA‐15 and CMK‐3 retained higher activity of 85–93% after four batches of repeated use. The observed efficiency of XynC immobilized on CMK‐3 and SBA‐15 are higher than the reported values. The results showed that XynC immobilized on mesoporous carbon and silica matrices would be useful for production of XOS by enzyme recycling.

The Prospect of Photochemical Reactions in Confined Gel Media.

Nature is intrinsically able to control kinetics, conversion, and selectivity of biochemical processes by means of confined reaction environments such as enzyme pockets, bilayer membranes, micelles, vesicles, cells, or bioorganic frameworks. The main reason for this fact is the optimal molecular alignment and restricted motion of reactant molecules compared to those found in bulk solution. Under this inspiration, a number of synthetic photo-nanoreactors based on supramolecular self-assembled systems have been developed during the last decades, including mesoporous inorganic materials, microemulsions, micelles, vesicles, lipid bilayer foams, polyelectrolyte nanoparticles, etc. In a broader sense, nanoreactor technology constitutes nowadays a promising tool to enhance organic synthesis under sustainable reaction conditions. In general, nanoreactors change the essential properties of the molecules within them, thus affecting their chemical reactivity. Among the nanoreactor-like systems described in the literature to facilitate photochemical processes, the more recent use of viscoelastic supramolecular gels, typically made of low-molecular-weight (LMW) compounds self-assembled through noncovalent interactions, as compartmentalized reaction media is particularly appealing due to the versatility of these materials in terms of fabrication, properties, and processability. Furthermore, the high specific surface areas found in supramolecular gels, their stimuli-responsive reversibility, good diffusion properties enhancing the interactions between reactants and the three-dimensional (3D) porous network, functional tunability, and blocking effect of external oxygen are some of the most important features that can benefit photoinduced processes carried out in confined gel media. Not surprisingly, the efficiency of photochemical processes inside gel media is largely dependent on the type of reaction, characteristics of the gel network, solvent nature, reactant properties, and reaction conditions. Thus, the main focus of this Account is to provide a concise overview of the most relevant examples reported by us and others in order to illustrate the main advantages associated with the emerging use of gel-based materials as nonconventional reaction media to facilitate and control photochemical reactions. In particular, photodimerization, triplet-triplet annihilation upconversion (TTA-UC) coupled to single electron transfer (SET), photooxidation, photoreduction, and trifluoromethylation reactions will be illustrated during the discussion. These examples suggest that gel-based media can provide a versatile platform for the discovery of new reaction pathways and facilitate the way that photochemical reactions are traditionally carried out in academia and industry in terms of reaction conditions and required infrastructure. In addition, the use of physical or chemical gels as reaction systems may also accelerate high-throughput screening of photocatalysts. Overall, a judicious choice of gelators, reactants, solvent, and reaction conditions for the assembly of these gelators is crucial for controlling conversion, kinetics, and selectivity of intragel photoinduced processes.

The Effects of Textural Parameters of Zeolite and Silica Materials on the Protective and Functional Properties of Polymeric Nonwoven Composites

Zeolites are micro- and mesoporous aluminosilicate minerals (both natural and industrially produced) widely used as catalysts and sorbents in domestic and commercial water purification and separation technologies. Their ability to selectively adsorb gases (i.e., water vapor, carbon dioxide, and sulfur dioxide removal) from an air stream makes them suitable for applications in odor reducing media used in filtering facepiece respirators (FFRs). FFRs are multilayer products in which the most important role is played by high-performance melt-blown electret nonwovens modified with activated carbon to adsorb malodorous compounds. Replacing carbon sorbents with zeolites could increase the efficiency of odor abatement, thus alleviating work-related hazards for individuals exposed to malodorous substances with adverse effects on human well-being. The objective of the present work was to analyze the influence of the textural parameters of zeolite and mesoporous silica materials on the protective and functional properties of polymeric nonwoven composites containing them. In our experiments, the longest breakthrough time against ammonia vapor was found for a nonwoven composite containing the inorganic mesoporous silica material type MCM-41. It was also characterized by high filtration efficiency against aerosols with solid and liquid dispersed phases (97% and 99% for sodium chloride and paraffin oil mist, respectively) at an airflow resistance of approximately 330 Pa. In turn, the composites containing the molecular sieve (SM-zeolite ZSM-5) exhibited the longest breakthrough time for acetone and cyclohexane vapors at the maximum allowable concentrations of 235 ppm and 81 ppm, respectively. Basic filtration tests showed that the composite was 97% effective against both test aerosols at an airflow resistance of 283.5 Pa.

Effectiveness of novel xerogels adsorbents for cadmium uptake from aqueous solution in batch and column modes: Synthesis, characterization, equilibrium, and mechanism analysis

In the present study, new organic–inorganic mesoporous materials are prepared. The FTIR, SEM, 29Si CP MAS NMR and nitrogen adsorption–desorption experiments are utilized to portray the novel xerogels. Application for the cadmium(II) uptake from aqueous solution using the as-synthesized hybrid materials as adsorbent is explored. Operating parameters influencing the adsorption procedure, for instance, solution pH, contact time and temperature are contemplated. The adsorption kinetic analysis abides by pseudo-second-order model and the intra-particle diffusion model display that the rate-controlled step is directed by film-diffusion before all else and afterward is taken by intra-particle diffusion. Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models are assigned to portray the adsorption isotherms. Experimental data seem to be adequate with Langmuir model showing high monolayer adsorption capacities of Cd(II) onto both novel adsorbents (507–493 mg g−1). Mean free energy values assessed from d–R isotherm prescribe that cadmium sequestration by the two hybrid materials eventuated by chemisorption. Besides, the dynamic process exposed relatively high breakthrough capacity for both xerogels and the column data are well validated by Thomas model. Computed thermodynamic parameters depict that the adsorption of Cd(II) ions onto the two adsorbents is favorable and exothermic in nature. FTIR and XPS analysis, uncover that the fundamental mechanism of the cadmium removal is the chelation of metal ions with the ligating nitrogen atoms (N) of amino functionalized xerogel (M1). Though, onto sulfhydryl-functionalized xerogel (M2) it is presumably through the ion-exchange reaction between Cd2+ ions and (SH) groups. The desorption investigation show that the synthesized hybrid materials possess a remarkable reusability. Prior tests produced on electroplating effluents reveal that the as-prepared xerogel could be strongly used for the cadmium uptake from real wastewater.

A highly ordered chiral inorganic mesoporous material used as stationary phase for high-resolution gas chromatographic separations

A highly ordered chiral mesoporous silica-coated capillary column has been used for high-resolution gas chromatographic separations. The column has excellent selectivity, not only for the separation of isomers, polycyclic aromatic hydrocarbons, linear alkanes, long chain alkanes, Grob’s test mixture and aromatic hydrocarbons, but also for the resolution of different classes of chiral compounds. Additionally, the column exhibits high column efficiency, excellent temperature resistance, and analysis times are short. This is the first report of a highly ordered chiral inorganic mesoporous silica used in separation science.

Multiscale Phase Separations for Hierarchically Ordered Macro/Mesostructured Metal Oxides.

Porous architectures play an important role in various applications of inorganic materials. Several attempts to develop mesoporous materials with controlled macrostructures have been reported, but they usually require complicated multiple-step procedures, which limits their versatility and suitability for mass production. Here, a simple approach for controlling the macrostructures of mesoporous materials, without templates for the macropores, is reported. The controlled solvent evaporation induces both macrophase separation via spinodal decomposition and mesophase separation via block copolymer self-assembly, leading to the formation of hierarchically porous metal oxides with periodic macro/mesostructures. In addition, using this method, macrostructures of mesoporous metal oxides are controlled into spheres and mesoporous powders containing isolated macropores. Nanocomputed tomography, focused ion beam milling, and electron microscopy confirm well-defined macrostructures containing mesopores. Among the various porous structures, hierarchically macro/mesoporous metal oxide is employed as an anode material in lithium-ion batteries. The present approach could provide a broad and easily accessible platform for the manufacturing of mesoporous inorganic materials with different macrostructures.

Effect of inorganic mesoporous carriers on 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol-loaded solid self-emulsifying drug delivery system: Physicochemical characterization and bioavailability in rats

The purpose of this study was to assess the impact of inorganic mesoporous carriers on the physicochemical properties and oral bioavailability of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG)-loaded solid self-emulsifying drug delivery system (solid SEDDS). Numerous PLAG-loaded solid SEDDS formulations were prepared by spray drying technique with sodium laurylsulfate (SLS), butylated hydroxyanisole (BHA) and inorganic mesoporous materials as a surfactant, antioxidant and solid carrier, respectively. The mesoporous materials, such as calcium silicate, silicon dioxide and magnesium aluminosilicate were used as the solid carriers. Their physicochemical properties, solubility, dissolution and pharmacokinetic studies in rats were performed compared with drug alone. Three solid SEDDSs composed of PLAG/BHA/SLS/mesopous carrier at the weight ratio of 1:0.0002:0.25:0.5 resulted in a small emulsion droplet and excellent drug loading efficiency. The solid SEDDS formulations prepared with calcium silicate and silicon dioxide showed a rough-surfaced irregular shape and rough-surfaced spheres, respectively. Magnesium aluminosilicate generated a sticky powder, due to its relatively low specific surface area, resulting in insufficient adsorption of PLAG. These solid SEDDSs improved the solubility, dissolution and oral bioavailability of PLAG. Ultimately, the solid SEDDS prepared with silicon dioxide resulted in the best drug loading efficiency, shape, solubility, dissolution and oral bioavailability due to its great specific surface area. Therefore, mesoporous carriers with different specific surface areas markedly influenced the physicochemical properties, solubility, dissolution and oral bioavailability of PLAG-loaded solid SEDDS.

Recent progress of chiral stationary phases for separation of enantiomers in gas chromatography.

Chromatography techniques based on chiral stationary phases are widely used for the separation of enantiomers. In particular, gas chromatography has developed rapidly in recent years due to its merits such as fast analysis speed, lower consumption of stationary phases and analytes, higher column efficiency, making it a better choice for chiral separation in diverse industries. This article summarizes recent progress of novel chiral stationary phases based on cyclofructan derivatives and chiral porous materials including chiral metal-organic frameworks, chiral porous organic frameworks, chiral inorganic mesoporous materials, and chiral porous organic cages in gas chromatography, covering original research papers published since 2010. The chiral recognition properties and mechanisms of separation toward enantiomers are also introduced.