title: Delivery modulation in silica mesoporous supports via alkyl chain pore outlet decoration.
abstract: This article focuses on the study of the release rate in a family of modified silica mesoporous supports. A collection of solids containing ethyl, butyl, hexyl, octyl, decyl, octadecyl, docosyl, and triacontyl groups anchored on the pore outlets of mesoporous MCM-41 has been prepared and characterized. Controlled release from pore voids has been studied through the delivery of the dye complex tris(2,2'-bipyridyl)ruthenium(II). Delivery rates were found to be dependent on the alkyl chain length anchored on the pore outlets of the mesoporous scaffolding. Moreover, release rates follow a Higuchi diffusion model, and Higuchi constants for the different hybrid solids have been calculated. A decrease of the Higuchi constants was observed as the alkyl chain used to tune the release profile is longer, confirming the effect that the different alkyl chains anchored into the pore mouths exerted on the delivery of the cargo. Furthermore, to better understand the relation between pore outlets decoration and release rate, studies using molecular dynamics simulations employing force-field methods have been carried out. A good agreement between the calculations and the experimental observations was observed.
authors.affiliation: Centro de Reconocimiento Molecular y Desarrollo Tecnológico (IDM), Unidad Mixta Universitat Politècnica de València-Universitat de València, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Aznar
authors.forename: Félix
authors.initials: F
authors.lastname: Sancenón
authors.forename: M Dolores
authors.initials: MD
authors.lastname: Marcos
authors.forename: Ramón
authors.initials: R
authors.lastname: Martínez-Máñez
authors.forename: Pieter
authors.initials: P
authors.lastname: Stroeve
authors.forename: Joan
authors.initials: J
authors.lastname: Cano
authors.forename: Pedro
authors.initials: P
authors.lastname: Amorós
mesh_terms: D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D009942:Organometallic Compounds / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D009942:Organometallic Compounds; C415768:tris(2,2'-bipyridyl)ruthenium(II); D012822:Silicon Dioxide