Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO2 Capture and Dye Separation

Ordered Mesoporous Crystalline Frameworks Toward Promising Energy Applications

Ordered mesoporous crystalline frameworks (MCFs), which possess both functional frameworks and well-defined porosity, receive considerable attention because of their unique properties including high surface areas, large pore sizes, tailored porous structures, and compositions. Construction of novel crystalline mesoporous architectures that allows for rich accessible active sites and efficient mass transfer is envisaged to offer ample opportunities for potential energy-related applications. In this review, the rational synthesis, unique structures, and energy applications of MCFs are the main focus. After summarizing the synthetic approaches, an emphasis is placed on the delicate control of crystallites, mesophases, and nano-architectures by concluding basic principles and showing representative examples. Afterward, the currently fabricated components of MCFs such as metals, metal oxides, metal sulfides, and metal-organic frameworks are described in sequence. Further, typical applications of MCFs in rechargeable batteries, supercapacitors, electrocatalysis, and photocatalysis are highlighted. This review ends with the possible development and synthetic challenges of MCFs as well as a future prospect for high-efficiency energy applications, which underscores a pathway for developing advanced materials.

Neutralization-mediated extraction of amphiphilic organic molecules for obtaining high-quality mesoporous alumina

A solvent extraction method was improved using organic bases such as triethylamine (Et3N) that neutralize HCl effectively and stabilize sol-gel derivative alumina frameworks as insoluble species, thereby achieving removal of EOnPOmEOn at a rate higher than 90% to obtain high-quality mesoporous alumina.

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.

Unveiling the mechanism of methylcellulose-templated synthesis of Al2O3 microspheres with organic solvents as swelling agents in microchannel

Herein, we report a systematic investigation of the preparation of large-pore-volume Al₂O₃ microspheres using a complex synthesis system with methylcellulose (MC) as the template and gelation initiator and organic solvents as the swelling agent and carrier medium under the flow characteristics of a coaxial microchannel. The adsorption of MC micelles on boehmite colloidal nanoparticles (NPs) was proven and determined by interfacial tension measurements, dynamic light scattering, and cryogenic transmission electron microscopy. Isothermal titration calorimetry demonstrated that the adsorption process was caused by nonspecific hydrophobicity; one binding site was involved, and the affinity constant was 1060 M^-1. When the MC:NPs mass ratio exceeded 0.1, the template-NP bridged each other to form large aggregates, thereby forming large mesopores and enhancing the gelation speed. Alkanes, alcohols, and amines were applied to further enhance the porosity, and the swelling capacities were investigated experimentally and theoretically. Amines were efficient swelling agents owing to their excellent ability to swell MC micelles and insert into the acid colloid network. The coaxial microchannel was subjected to molding; this process significantly influenced the morphology and textural properties owing to the internal circulation during droplet formation. When trihexylamine with suitable steric hindrance, alkalinity, and polarity was used as the swelling agent, the microspheres exhibited an optimal specific surface area of 403 m²/g and a pore volume of 1.85 cm³/g.

Preparation Methods and Performance Analysis of Polyanthra-Quinone/Carbon Nanotube Composites for Capturing Carbon Dioxide

Carbon capture is one of the important methods to achieve carbon neutrality. In this paper, a simple and reliable method for the preparation of poly(anthraquinone)/multi-walled carbon nanotube composites (PAQ/MWCNTs) for capturing carbon dioxide is proposed. Using constant magnetic stirring, 1,4-anthraquinone (1,4-AQ) was allowed to accumulate on multi-walled carbon nanotube (MWCNTs) substrates via π–π. The poly(anthraquinone)/multi-walled carbon nanotube composites were produced by this continuous process. Besides, the carbon cloth electrode prepared from PAQ/MWCNTs composites was subjected to redox potentials for carbon dioxide capture. Results showed that PAQ/MWCNTs composites had good redox reversibility, their carbon dioxide capture capacity was 7.80 mmol·g−1 while the material utilization rate reaches reached 73.4%.

Transient Laser-Annealing-Induced Mesophase Transitions of Block Copolymer-Resol Thin Films

Block copolymer self-assembly-derived thin films provide direct access to two- and three-dimensional periodically ordered mesostructures as enablers for many nanotechnology applications. This report describes laser-annealing-induced disorder-order mesophase transitions of polystyrene-block-poly(ethylene oxide)/resol hybrid thin films over a range of laser temperatures (∼45 to 525 °C) and short dwell times (0.25 to 100 ms), revealing the non-equilibrium ordering and disordering kinetics and behaviors. We found that a combination of transient laser temperature of ∼275 °C and annealing dwell time of 100 ms provided the most optimal kinetic and thermodynamic control of the diffusivities of hybrid mesophases and photothermal-induced resol polymerization, yielding long-range ordered films resembling an in-plane body-centered cubic sphere morphology. A clear understanding of hybrid thin film mesophase self-assembly under non-equilibrium laser annealing could open new avenues to introduce novel chemistries and rapidly achieve nanoscale periodic order suitable for the patterning of complex structures, electronics, sensing, and emerging quantum materials.