Synthesis and Characterization of Superhydrophobic, Self-cleaning NIR-reflective Silica Nanoparticles.
Multifunctional coatings offer many advantages towards protecting various surfaces. Here we apply aggregation induced segregation of perylene diimide (PDI) to control the surface morphology and properties of silica nanoparticles. Differentially functionalized PDI was incorporated on the surface of silica nanoparticles through Si-O-Si bonds. The absorption and emission spectra of the resultant functionalised nanoparticles showed monomeric or excimeric peaks based on the amounts of perylene molecules present on the surface of silica nanoparticles. Contact angle measurements on thin films prepared from nanoparticles showed that unfunctionalised nanoparticles were superhydrophilic with a contact angle (CA) of 0°, whereas perylene functionalised silica particles were hydrophobic (CA > 130°) and nanoparticles functionalised with PDI and trimethoxy(octadecyl)silane (TMODS) in an equimolar ratio were superhydrophobic with static CA > 150° and sliding angle (SA) < 10°. In addition, the near infrared (NIR) reflectance properties of PDI incorporated silica nanoparticles can be used to protect various heat sensitive substrates. The concept developed in this paper offers a unique combination of super hydrophobicity, interesting optical properties and NIR reflectance in nanosilica, which could be used for interesting applications such as surface coatings with self-cleaning and NIR reflection properties.
Department of Chemistry, 3 Science Drive 3, National University of Singapore (NUS), 117543, Singapore.
Deepa
D
Sriramulu
Department of Chemistry, 3 Science Drive 3, National University of Singapore (NUS), 117543, Singapore.
Ella Louise
EL
Reed
NUSNNI-NanoCore, National University of Singapore, 117411, Singapore.
Meenakshi
M
Annamalai
NUSNNI-NanoCore, National University of Singapore, 117411, Singapore.|Department of Physics, National University of Singapore, 117542, Singapore.|Department of Electrical and Computer Engineering, National University of Singapore, 117576, Singapore.|Department of Material Science and Engineering, National University of Singapore, 117575, Singapore.|NUS Graduate School for Integrative Sciences &Engineering, National University of Singapore, 117456, Singapore.
Thirumalai Venky
TV
Venkatesan
Department of Chemistry, 3 Science Drive 3, National University of Singapore (NUS), 117543, Singapore.
Suresh
S
Valiyaveettil