title: Size, Stability, and Porosity of Mesoporous Nanoparticles Characterized with Light Scattering.
abstract: Silicon-based mesoporous nanoparticles have been extensively studied to meet the challenges in the drug delivery. Functionality of these nanoparticles depends on their properties which are often changing as a function of particle size and surrounding medium. Widely used characterization methods, dynamic light scattering (DLS), and transmission electron microscope (TEM) have both their weaknesses. We hypothesize that conventional light scattering (LS) methods can be used for a rigorous characterization of medium sensitive nanoparticles' properties, like size, stability, and porosity. Two fundamentally different silicon-based nanoparticles were made: porous silicon (PSi) from crystalline silicon and silica nanoparticles (SN) through sol-gel process. We studied the properties of these mesoporous nanoparticles with two different multiangle LS techniques, DLS and static light scattering (SLS), and compared the results to dry-state techniques, TEM, and nitrogen sorption. Comparison of particle radius from TEM and DLS revealed significant overestimation of the DLS result. Regarding to silica nanoparticles, the overestimation was attributed to agglomeration by analyzing radius of gyration and hydrodynamic radius. In case of PSi nanoparticles, strong correlation between LS result and specific surface area was found. Our results suggest that the multiangle LS methods could be used for the size, stability, and structure characterization of mesoporous nanoparticles.
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, FI-20500, Turku, Finland. martti.kaasalainen@utu.fi.
authors.forename: Martti
authors.initials: M
authors.lastname: Kaasalainen
authors.affiliation: Department of Chemistry, University of Helsinki, FI-00014 HY, Helsinki, Finland.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Aseyev
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Eva
authors.initials: E
authors.lastname: von Haartman
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Didem Şen
authors.initials: DŞ
authors.lastname: Karaman
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, FI-20500, Turku, Finland.
authors.forename: Ermei
authors.initials: E
authors.lastname: Mäkilä
authors.affiliation: Department of Chemistry, University of Helsinki, FI-00014 HY, Helsinki, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Tenhu
authors.affiliation: Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, FI-20520, Turku, Finland.
authors.forename: Jessica
authors.initials: J
authors.lastname: Rosenholm
authors.affiliation: Laboratory of Industrial Physics, Department of Physics and Astronomy, University of Turku, FI-20500, Turku, Finland. jarno.salonen@utu.fi.
authors.forename: Jarno
authors.initials: J
authors.lastname: Salonen
keywords: Biorelevant characterization; Light scattering; Mesoporous silica nanoparticle; Particle size; Porosity; Porous silicon