Synthesis and physicochemical characterization of mesoporous SiO2 nanoparticles
- DOI
- Language of the publication
- English
- Date
- 2014-05-18
- Type
- Article
- Author(s)
- Das, Dharani
- Yang , Yong
- O'Brien, Julie S.
- Breznan, Dalibor
- Nimesh, Surendra
- Bernatchez, Stéphane
- Hill, Myriam
- Sayari, Abdelhamid
- Vincent, Renaud
- Kumarathasan, Prem
- Publisher
- Hindawi
Abstract
There exists a knowledge gap in understanding potential toxicity of mesoporous silica nanoparticles. A critical step in assessing toxicity of these particles is to have a wide size range with different chemistries and physicochemical properties. There are several challenges when synthesizing mesoporous silica nanoparticles over a wide range of sizes including (1) nonuniform synthesis protocols using the same starting materials, (2) the low material yield in a single batch synthesis (especially for particles below 60- 70 nm), and (3)morphological instability during surfactant removal process and surface modifications. In this study, we synthesized a library of mesoporous silica nanoparticles with approximate particle sizes of 25, 70, 100, 170, and 600 nm. Surfaces of the silica nanoparticles were modified with hydrophilic-CH2-(CH2)2-COOH and relatively hydrophobic-CH2-(CH2)10-COOH functional groups. All silica nanoparticles were analysed for morphology, surface functionality, surface area/pore volume, surface organic content, and dispersion characteristics in liquid media. Our analysis revealed the synthesis of a spectrum of monodisperse bare and surface modified mesoporous silica nanoparticles with a narrow particle size distribution and devoid of cocontaminants critical for toxicity studies. Complete physicochemical characterization of these synthetic mesoporous silica nanoparticles will permit systematic toxicology studies for investigation of structure-activity relationships.
Plain language summary
Nanoparticles are very small in size (one billionth of one metre in at least one dimension). Particles in the nano size range exhibit specific properties, which in many cases are different from larger particles of the same materials. These properties vary with nanoparticle size and surface chemistry. The unique properties of nanomaterials have been utilized in the production/manipulation of consumer products to impart novel characteristics. Silica, the most common element (constituent of sand), when prepared in the nano-scale can be used in various technologies, such as catalytic supports for chemical processing, electronics, and in various advanced biomedical applications including medical imaging of tumours. Although silica nanoparticles become very useful at the nano-scale, the properties that make them very useful, may also affect the way they interact with biological systems to change their toxicity profiles. A particular challenge for studying toxicity is the lack of well characterized silica nanoparticles at different sizes and various corresponding surface modified forms. In this study, Health Canada scientists synthesized and characterized a library of silica nanoparticles with approximate particle sizes of 25, 70, 100, 170, and 600 nm. The surfaces of the SiNPs of all sizes were modified with one long chain and one short chain organic group, and the properties of these nanoparticles were studied in both dry and liquid medium, thus producing a fully characterized library of materials whose toxicological properties can be studied in future investigations.
Subject
- Health,
- Health and safety