Enlarged pore size in nanoparticulated bimodal porous silicas: Improving accessibility

• Published in: Microporous and mesoporous materials Vol. 221; pp. 150 - 158
• Main Authors: Moragues, Alaina, Guillem, Carmen, Mauri-Aucejo, Adela, Tortajada, Marta, Beltrán, Aurelio, Beltrán, Daniel, Amorós, Pedro
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-02-2016
• Subjects: Bimodal porosity; Mesoporous materials; Silica nanoparticles; Swelling agents; Template synthesis; Silica nanoparticles; Bimodal porosity; Template synthesis; Mesoporous materials; Swelling agents
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2015.09.037

Mass-transfer kinetics seems to be highly favored in siliceous materials constructed from the aggregation of mesoporous nanoparticles. Besides intra-particle mesopores, over the course of the aggregation process an inter-particle (textural) large pore system is generated. Diffusion constrains through the resulting hierarchically structured pore systems mainly depend on the characteristics of the intra-particle mesopores. By using alkanes as swelling agents, we have been able to significantly increase the intra-particle mesopore size in previously well characterized UVM-7 materials. The Winsor-III-like behavior associated with the presence of alkanes in the hydro-alcoholic reaction media used in the surfactant-assisted preparative procedure allows explaining the existence of limits to the mesopore size expansion. A preliminary study on enzyme adsorption by these UVM-7-modified solids offers promising results about their capabilities as supports for processing a variety of biomolecules.
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•The intra-particle mesopores in nanoparticulated bimodal porous silicas have been enlarged up to ca. 56%.•We have established the limits for the mesopore expansion on the basis of classical principles of colloid chemistry.•The resulting open architecture leads to an enhanced accessibility for guest species.