A facile one-step route to synthesize titania hollow microspheres with incontinuous multicavities

Micron-Sized Thiol-Functional Polysilsesquioxane Microspheres with Open and Interconnected Macropores: Effects of the System Composition on the Porous Structure and Particle Size of the Microspheres

Control of the porous structure and particle size is essential for improving the properties of polysilsesquioxane (PSQ) microspheres. Herein, using the strategy combining inverse suspension polymerization, two-step sol-gel- and polymerization-induced phase separation processes, micron-sized thiol-containing macroporous PSQ (TMPSQ) microspheres with controllable morphologies, adjustable particle diameters (4.9-17.3 μm), and pore sizes (40-3774 nm) were prepared. The morphology and size of the TMPSQ microspheres were characterized by SEM. The mercury intrusion method was employed to analyze the porous structure of the microspheres. The effects of the composition of the sol-gel disperse phase, the mass ratio of the sol-gel disperse phase to the oil continuous phase (WRW/O), and the Span 80 mass content in the oil continuous phase on the morphology, particle diameter and pore size of the TMPSQ microspheres were investigated. Results indicated that the composition of the sol-gel disperse phase determines the morphology and porous structure of the microspheres, and WRW/O and Span 80 content have remarkable impacts on the morphology and particle size of the microspheres. This study is beneficial to the design and fabrication of functional PSQ microspheres with desired properties and promising application prospects.

Macroporosity Control by Phase Separation in Sol-Gel Derived Monoliths and Microspheres

Macroporous and hierarchically macro/mesoporous materials (mostly monoliths and microspheres) have attracted much attention for a variety of applications, such as supporting or enabling materials in chromatography, energy storage and conversion, catalysis, biomedical devices, drug delivery systems, and environmental remediation. A well-succeeded method to obtain these tailored porous materials relies on the sol-gel technique, combined with phase separation by spinodal decomposition, and involves as well emulsification as a soft template, in the case of the synthesis of porous microspheres. Significant advancements have been witnessed, in terms of synthesis methodologies optimized either for the use of alkoxides or metal-salts and material design, including the grafting or immobilization of a specific species (or nanoparticles) to enable the most recent trends in technological applications, such as photocatalysis. In this context, the evolution, in terms of material composition and synthesis strategies, is discussed in a concerted fashion in this review, with the goal of inspiring new improvements and breakthroughs in the framework of porous materials.

Preparation of porous alumina microspheres via an oil-in-water emulsion method accompanied by a sol–gel process

Porous alumina microspheres prepared via a facile template-free approach followed by heat-treatment, exhibiting a three-dimensional interconnected structure.