Ultralarge Pore Size Research Articles

Calcination-free nanoarchitectonics of mesoporous conducting polymer@silica hybrids with ultra-large pores and their enhanced protein adsorption capacity

The nanohybrids of mesoporous conducting polymer@silica with ultra-large pore size are successfully in-situ synthesised from 3,4-propylenedioxythiophene (ProDOT) derived cationic surfactant and silica precursor assisted by co-solvent n-butanol at high temperature without any template removal process. The ultra-large mesopores pores are created in the nanohybrids without calcination step through an integrated approach of simple polymerisation and rearrangement of the conducting and hydrophobic monomeric unit, ProDOT unit followed by the pore swelling with the co-solvent and high-temperature hydrothermal treatment. By controlling the hydrothermal temperature and the amount of co-solvent, the pore size can be expanded from 11.6 nm to 27 nm. The prepared nanohybrid with ultra large pores exhibits a high adsorption capacity for large-sized protein (bovine serum albumin, BSA), and the adsorption capacity can be controlled with the adjustment of the pore size. The adsorption capacity of a nanohybrid with 27 nm is 166 mg/g, which is almost twice that of a nanohybrid with 11.6 nm (75 mg/g). The mesoporous conducting polymer@silica nanohybrids can be applied as a carrier for protein delivery or the support for enzymatic catalysis or biosensors.

A highly accessible copper single-atom catalyst for wound antibacterial application

Bacterial infection arised from multipathogenic bacteria is a tricky issue that attracts worldwide attentions. In this paper, a highly accessible copper single-atom catalyst (Cu SAC) supported by biocompatible N-doped mesoporous carbon nanospheres was synthesized with the emulsion-template method. The tightly anchored copper single-atom of the catalyst could effectively transform O2 into O2−• under ambient conditions by the ultra-large pore size (~ 23.80 nm) and small particle size (~ 97.71 nm). Due to multiple synergistically oxidative damages to biomolecules, the Cu SAC could be employed to eliminate different bacteria in vitro without the generation of multidrug resistance (MDR). Moreover, the Cu SAC could also promote wound healing in vivo by eradicating the propagation of bacteria at wound. It is envisioned that the Cu SAC with superior antibacterial performance could be applied in the treatment of related bacterial infection in future.

Fabrication of epidermal growth factor imprinted and demethylcantharidin loaded dendritic mesoporous silica nanoparticle: An integrated drug vehicle for chemo-/antibody synergistic cancer therapy

Currently, administration of antibodies combining with anti-cancer drugs strategies are powerful therapies options for certain cancers, however, the widely use of natural antibodies is still limited by the high cost and the risk of immunogenic reactions. In this study, an epidermal growth factor (EGF)-imprinted and anti-tumor agent demethylcantharidin (DMC) loaded nanoparticle which with ability of both serving as the artificial antibody and delivering DMC to be used for chemotherapy was designed. Polydopamine (PDA) was chosen as the molecular imprinting polymer (MIP) materials and coated into the pore channels of dendritic mesoporous silica nanoparticles (DMSN) which with nano size spherical shape and ultra-large pore size. Finally, DMC was introduced into the DMSN@MIP by coupling with the hydroxyl groups of PDA films. The successfully prepared DMSN@MIP-DMC was with specific EGF adsorption ability and high DMC loading capacity. In vitro and in vivo studies results showed that DMSN@MIP-DMC with affinity to EGF inhibit its binding to receptor epidermal growth factor receptor (EGFR), preventing receptor phosphorylation and further promote apoptosis of 4T1 cells induced by DMC. These results imply that DMSN@MIP-DMC has the potential to both serve as the artificial antibody and drug vehicle for delivering anti-tumor drugs.

Ordered mesoporous alumina with ultra-large pore size catalyze cinnamaldehyde to cinnamyl alcohol with high selectivity

At present, most of mesoporous alumina are synthesized by a soft template method with pore diameters of less than 10 nm, which tends to cause an amorphous structure and great limitations for the catalytic reaction. Therefore, we chose to use triblock copolymer as a template and self-assembly by solvent evaporation to synthesize an ultra-large mesoporous alumina without any pore expanding agents. The synthesized mesoporous alumina is used for the hydrogenation reaction of 4-methoxy cinnamaldehyde, and the mesoporous alumina exhibited high conversion and excellent selectivity. Compared with industrial synthesis of 4-methoxy cinnamyl alcohol, the reaction can be a complete conversion of 4-methoxy cinnamaldehyde to 4-methoxy cinnamyl alcohol without any by-products.

Versatile Nanoemulsion Assembly Approach to Synthesize Functional Mesoporous Carbon Nanospheres with Tunable Pore Sizes and Architectures.

Functional mesoporous carbons have attracted significant scientific and technological interest owning to their fascinating and excellent properties. However, controlled synthesis of functional mesoporous carbons with large tunable pore sizes, small particle size, well-designed functionalities, and uniform morphology is still a great challenge. Herein, we report a versatile nanoemulsion assembly approach to prepare N-doped mesoporous carbon nanospheres with high uniformity and large tunable pore sizes (5-37 nm). We show that the organic molecules (e.g., 1,3,5-trimethylbenzene, TMB) not only play an important role in the evolution of pore sizes but also significantly affect the interfacial interaction between soft templates and carbon precursors. As a result, a well-defined Pluronic F127/TMB/dopamine nanoemulsion can be facilely obtained in the ethanol/water system, which directs the polymerization of dopamine into highly uniform polymer nanospheres and their derived N-doped carbon nanospheres with diversely novel structures such as smooth, golf ball, multichambered, and dendritic nanospheres. The resultant uniform dendritic mesoporous carbon nanospheres show an ultralarge pore size (∼37 nm), small particle size (∼128 nm), high surface area (∼635 m2 g-1), and abundant N content (∼6.8 wt %), which deliver high current density and excellent durability toward oxygen reduction reaction in alkaline solution.

Highly effective antibacterial activity by the synergistic effect of three dimensional ordered mesoporous carbon-lysozyme composite

Aiming at developing a safe and efficient alternative to traditional drinking water disinfection, this work successfully synthesized a novel antibacterial material with high surface area, ultra large pore size and tunable loading of immobilized lysozyme. The immobilized enzymes exhibit high antibacterial efficacy without forming carcinogenic disinfection byproducts. Critical immobilization parameters were optimized to keep the activity of the immobilized enzyme at a high level. The immobilization of lysozymes on 3DOm COOH could be confirmed by the characterizations of transmission electron microscopy, X-ray diffraction and Zeta-Potential. In addition, the structural stability of lysozymes on 3DOm COOH were studied by Fourier transform infrared spectroscopy. The antibacterial performance of 3DOm COOH-Lyz were specifically investigated based on the disinfection efficacy of Staphylococcus aureus in water. The results revealed that the immobilization capacity and relative activity of immobilized lysozyme were 814mg/g carrier and 80%, respectively, under the optimal immobilization conditions. And the antibacterial material with the initial mass ratio of lysozyme and 3DOm COOH as 3:1 exhibited maximum bacteria removal efficiency (98.1%) at pH 5. Moreover, the reusability test indicated that 3DOm COOH-Lyz has certain operational stability, and remains 82% bacterial removal efficiency even in the fifth cycle, which provides a promising application for safe and efficient drinking water disinfection in small-scale and emergency water treatment.

Ordered Mesoporous Alumina with Ultra-Large Pores as an Efficient Absorbent for Selective Bioenrichment

Alumina has recently turned out to be effective in enrichment of biomacrolecules like phosphopeptides due to its good affinity to phosphor groups. Ordered mesoporous alumina (OMA) materials with high surface areas, regular porous structures, and large pore size are an ideal absorbent for the enrichment of phosphopeptides. Herein, a ligand-assisted solvent evaporation induced coassembly route is developed to synthesize OMA materials with an ultralarge pore size (16.0–18.9 nm) using a high-molecular-weight poly(ethylene oxide)-b-polystyrene (PEO-b-PS) as a soft template, aluminum acetylacetonate as a precursor, and tetrahydrofuran as a solvent. The obtained ordered mesoporous alumina shows high surface area (114–197 m2/g), large pore volume (0.16–0.34 cm3/g), and high thermal stability (up to 900 °C). The OMA materials show crystalline γ-Al2O3 frameworks with crystal size of ∼11 nm after calcination at 900 °C in air. Because of their high surface area, ultralarge pore size, and rich Lewis acid sites, the ob...

Synthesis of mesoporous silica material with ultra-large pore sizes and the HDS performance of dibenzothiophene

Ultra-large mesoporous silica materials using different micelle expanders including hexane, cyclohexane, 1,3,5-triisopropylbenzene and 1,3,5-triethylbenzene, have been successfully synthesized by the template of polymer surfactant of P123 (Aldrich, EO20PO70EO20). Among all the used micelle expanders, highly ordered cubic mesoporous silica material (SBA-16@hexane) with ultra-large pore size was obtained by using hexane. All the obtained samples were well characterized by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), nitrogen adsorption–desorption, UV–vis diffuse reflectance spectroscopy (DRS), H2-TPR, pyridine-FTIR, 27Al MAS NMR, GC–MS and Raman. The synthesis mechanism was also proposed. Compared with the conventional SBA-16 (6.31 nm) synthesized taking polymer surfactant of F127 (propylene oxide block copolymer) as the template, the as-synthesized SBA-16@hexane had a pore diameter of 15.1 nm with a highly ordered mesostructure, which was the largest one among all the reported pore sizes of SBA-16 materials. The corresponding hydrodesulfurization (HDS) catalysts of NiMo/Al-SBA-16@hexane, NiMo/γ-Al2O3, and NiMo/Al-SBA-16 were prepared by using different supports respectively, furthermore, their HDS performances were evaluated adopting dibenzothiophene (DBT) as the probe reactant. The DBT HDS efficiencies over these catalysts followed the order: NiMo/Al-SBA-16@hexane > NiMo/γ-Al2O3 > NiMo/Al-SBA-16. The high activity of NiMo/Al-SBA-16@hexane can be attributed to the superior diffusivity of the novel support of SBA-16@hexane with ultra-large pore size.

On the support in cobalt Fischer–Tropsch synthesis—Emphasis on alumina and aluminates

Impact of the support in Fischer–Tropsch synthesis is discussed with emphasis on alumina and aluminates; in particular γ-alumina, α-alumina, Mg-aluminate and Ni-aluminate. Topics covered are the support in industrial type catalysts, pore characteristics, attrition of particles, pore diffusion, loading and heat treatment of aluminates, turn-over-frequency and selectivity to C5+ products. Comparison is made between the supports including γ-alumina with narrow, medium, large and ultra-large pore size. An attempt is made to decouple the effects of cobalt crystallite size, pore size and type of support; all of which are important for the degree of polymerization. Selectivity to C5+ is favored by supports containing large pores, i.e., pores made up of large crystallites of the support material that also are more inert in nature. Cobalt surface coverage of CHx reaction intermediates is coupled directly to product selectivity as well as to catalytic activity. A model is suggested to link changes in composition of the surface pool of intermediates with properties of the support. Strain in cobalt crystallites as they extend over several crystallites of the support is expected to play a decisive role. Finally, the effect of conversion and added water on Fischer–Tropsch synthesis is analyzed. It is shown that all supports exhibit a positive selectivity response to water vapor pressure, but more so for the large pore supports titania, Ni-aluminate and γ-alumina with larger pores. Adsorbed water on cobalt may facilitate CO activation and suppress hydrogen coverage. Activity response of water is similar, although an anomalous reduction in activity upon added water for narrow pore alumina is observed. The reduction in activity is ascribed to oxidation of cobalt, possibly due to condensation of water vapor.

Preparation and retention mechanism exploration of mesostructured cellular foam silica as stationary phase for high performance liquid chromatography

Siliceous mesostructured cellular foam (MCF) with highly interconnected porous structure, ultralarge pore size and relatively uniform particle size (3–5μm) was prepared to achieve the mixed-mode and efficient separation of intact proteins. And molecular sieving effect for the first time played an important role in protein separation using mesoporous silica materials as HPLC stationary phase. The spherical silica particles were synthesized via hydrothermal method and the pore size was easily regulated by adding NH4F as well as altering the aging time. After aminopropyl derivatization, the chromatographic performance of functionalized mesoporous silica particles was investigated in comparison with those without modification and commercial NH2 column, and their mixed-mode retention mechanisms were investigated in detail. The superior separation performance for the retention of proteins was obtained on our home-made column in comparison with commercial NH2 column. The influences of aminopropyl derivatization and mobile phase composition on the column property were also investigated. Moreover, the home-made column showed similar performance for separation of polar anilines and neutral PAHs with the commercial column, owing to mixed-mode retention mechanisms including p–π stacking, electron interaction, hydrophobic effect, π–π EDA interaction and hydrogen bonding. All these results indicated that the aminopropyl modified MCF would be promising in the mixed-mode and efficient separation of biomolecules in addition with small molecules.

Synthesis of Al-Containing Spherical Mesocellular Silica Foams with Different Pore Sizes and Their Applications as Catalyst Supports for Hydrodesulfurization of Dibenzothiophene

In the present work, a series of Al-containing spherical mesostructured cellular silica foams (SMCFs) with different ultra-large pore sizes were successfully synthesized by simply adjusting the mass ratio (x) of the swelling agent 1,3,5-trimethylbenzene (TMB) to P123. The as-synthesized Al-SMCFs-x were utilized as NiMo catalyst supports for the hydrodesulfurization of dibenzothiophene. The characterization results showed that, compared with other studied NiMo/Al-SMCFs-x catalysts, the NiMo/Al-SMCFs-1.25 catalyst exhibited higher sulfidation degree, higher dispersions of Ni and Mo species, shorter length, and lower stacking number of MoS2 slabs. It was also found that the NiMo/Al-SMCFs-1.25 catalyst possessed suitable physicochemical parameters [i.e., ultra-large pore size (27.5 nm), high surface area (383 m2 g−1), and large pore volume (1.34 cm3 g−1), resulting in the formation of more type II active sites with more brim active sites. Consequently, the NiMo/Al-SMCFs-1.25 catalyst displayed outstanding catalytic performance for the hydrodesulfurization of dibenzothiophene.

Synthesis and Characterization of Gyroidal Mesoporous Carbons and Carbon Monoliths with Tunable Ultralarge Pore Size

Ordered mesoporous carbons with high pore accessibility are of great interest as electrodes in energy conversion and storage applications due to their high electric and thermal conductivity, chemical inertness, and low density. The metal- and halogen-free synthesis of gyroidal bicontinuous mesoporous carbon materials with uniform and tunable pore sizes through bottom-up self-assembly of block copolymers thus poses an interesting challenge. Four double gyroidal mesoporous carbons with pore sizes of 12, 15, 20, and 39 nm were synthesized using poly(isoprene)-block-poly(styrene)-block-poly(ethylene oxide) (ISO) as structure-directing triblock terpolymer and phenol-formaldehyde resols as carbon precursors. The highly ordered materials were thermally stable to at least 1600 °C with pore volumes of up to 1.56 cm(3) g(-1). Treatment at this temperature induced a high degree of sp(2)-hybridization and low microporosity. Increasing the resols/ISO ratio led to hexagonally packed cylinders with lower porosity. A single gyroid carbon network with high porosity of 80 vol % was obtained using a similar synthesis strategy. Furthermore, we present a method to fabricate monolithic materials of the gyroidal carbons with macroscopic shape and thickness control that exhibit an open and structured surface with gyroidal features. The gyroidal materials are ideally suited as electrode materials in fuel cells, batteries, and supercapacitors as their high, three-dimensionally connected porosity is expected to allow for good fuel or electrolyte accessibility and to prevent total pore blockage.

Synthesis of highly dispersed mesostructured cellular foam silica sphere and its application in high-performance liquid chromatography

Highly dispersed mesostructured cellular foam silica spheres of relatively uniform micrometer size (3.5–4.5μm) were successfully prepared using a triblock copolymer EO20PO70EO20 as the structure-directing agent accompanied by TMB and K2SO4. Both two additives have effective influence and K2SO4 have better performance than other inorganic salts such as KCl and NaCl. The pore size and surface area were tuned by TMB and NH4F. The resultant S-MCFs were modified with C18 group before being used as the HPLC stationary phase for effective separation of aromatic compounds and phthalic acid esters. The perfect spherical morphology and large pore volume gave rise to low and stable back pressure. High surface area, ultralarge pore size and unique pore structure would permit high flow rates and afford the possibility for fast separation.

Development of a method for methylated DNA enrichment with functionalized mesocellular silica foams immobilized with methyl CpG binding domain

To develop a method for enriching methylated DNA in clinical samples using mesocellular silica foams (MCFs) immobilized with methyl-CpG binding domain (MBD). MCFs with ultra-large pore size were synthesized, functionalized and immobilized with GST-MBD. The large cage-like pore structures of MCF materials was retained after functionalization and immobilization, with pore diameter of 55 nm, window size of 30 nm, and a high pore volume of 1.0 cm(3)/g. The loading amount of MBD was as high as 53 wt%. Immobilized MBD showed high binding activity and stability. In a binding buffer with salt concentrations ranging 500-550 mmol/L, the MCF-MBD can selectively enrich methylated DNA from the mixed DNA solution. The MCF-MBD method may offer a better choice for high-throughout DNA methylation screening, and has laid a foundation for clinical application, prenatal diagnosis and research on DNA methylation-related genetic diseases.

Siliceous mesocellular foam for high-performance liquid chromatography: Effect of morphology and pore structure

Spherical siliceous mesocellular foam (MCF) particles with an average particle size of 4.8 μm have been successfully prepared. These spherical particles were tailored in pore sizes and surface areas. They were functionalized with C 8 or C 18 groups, and applied towards reversed phase high-performance liquid chromatography (HPLC) column separations. Their high surface areas gave rise to very good retention characteristics, as illustrated in the separation of a series of alkylbenzene solutes with increasing chain length. The highly interconnected porous structure and ultralarge pore size of MCF allowed the columns to be used at high flow rates without much loss in column efficiency. The column efficiency and peak symmetry were further improved by eliminating the micropores of the stationary phase. The reversed phase column packed with C 18-modified spherical MCF particles provided for excellent separation of different deoxynucleosides, illustrating the broad applicability of these materials due to their controlled pore size.