A Quantitative Approach to Characterize the Surface Modification on Nanoparticles Based on Localized Dielectric
Taketo Mochizuki1, Shota Sampei1, Keishi Suga1
1Department of Chemical Engineering, Tohoku University, Sendai, Miyagi 9808579, Japan.
Surface modification of silica nanoparticles (SiO 2 ) using silane coupling agents improves their dispersibility. The volume fraction of organic modifiers (ϕ R ) reliably predicts the dielectric environment and properties of these hybrid nanoparticles.
Area of Science:
- Materials Science
- Surface Chemistry
- Nanotechnology
Background:
- Oxide nanoparticles (NPs), such as silica (SiO 2 ), often have poor dispersibility in organic media due to their hydrophilic surfaces.
- Surface modification using silane coupling agents is a key strategy to enhance NP compatibility with low-dielectric-constant solvents and polymers.
Purpose of the Study:
- To quantitatively evaluate the surface modification of SiO 2 NPs using octyltriethoxysilane (OTES) and dodecyltriethoxysilane (DTES).
- To investigate the impact of surface modification on NP properties, including Hansen solubility parameters (HSP) and local dielectric environments.
- To establish a correlation between the degree of surface modification and the dielectric properties of the modified NPs.
Main Methods:
- Functionalization of SiO 2 NPs with OTES (C8) and DTES (C12).
- Quantitative evaluation of surface modification using the ratio of modifier to silanol group (θ) and volume fraction of organic modifier (ϕ R ).
- Characterization of surface properties using Hansen solubility parameters (HSP) and analysis of local dielectric environments with a solvatochromic dye (Laurdan).
Main Results:
- Surface modification significantly altered the polarity (δ P ) of SiO 2 NPs.
- A strong correlation was observed between the volume fraction of organic modifier (ϕ R ) and the apparent dielectric environment (ε app ) surrounding the NPs.
- Surface-modified NPs with higher ϕ R (≥0.15) showed well-organized modifiers, indicated by generalized polarization (GP) > 0.
Conclusions:
- The volume fraction of organic modifier (ϕ R ) is a reliable metric for understanding the properties of surface-modified NPs.
- The local dielectric environment and organization of modifiers on NP surfaces can be effectively predicted by analyzing ϕ R .
- Apparent dielectric environment (ε app ) and generalized polarization (GP) are valuable tools for characterizing inorganic-organic hybrid NPs.
More Related Videos
08:19Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles
Published on: March 2, 2016
09:12Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering
Published on: June 1, 2016
