Tuning the hydrophobic properties of silica particles by surface silanization using mixed self-assembled monolayers

• Published in: Journal of colloid and interface science Vol. 318; no. 2; pp. 372 - 379
• Main Authors: Kulkarni, Sneha A., Ogale, Satishchandra B., Vijayamohanan, Kunjukrishanan P.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.02.2008; Elsevier
• Subjects: Alkyltrichlorosilane; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Hydrophobic and Hydrophilic Interactions; Membranes, Artificial; Particle Size; Silanes - chemistry; Silanization; Silica particles; Silicon Dioxide - chemistry; Spectroscopy, Fourier Transform Infrared - methods; Superhydrophobicity; Surface physical chemistry; Surface Properties; Temperature; Thermogravimetry; Alkyltrichlorosilane; Silanization; Silica particles; Superhydrophobicity; Particle; Self assembly; Mixed monolayer; Hydrophobicity; Silica
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2007.11.012

Here we describe a novel method of preparing hydrophobic silica particles (100–150 nm; water contact angle of dropcasted film ranging from 60° to 168°) by surface functionalization using different alkyltrichlorosilanes. During their preparation, the molecular surface roughness is also concurrently engineered facilitating a change in both the surface chemical composition and the geometrical microstructure to generate hierarchical structures. The water contact angle has been measured on drop-cast film surface. The enhancement in the water contact angle on 3D (curved) SAMs in comparison to that on 2D (planar) surface is discussed using the Cassie–Baxter equation. These silica particles can be utilized for many potential applications including selective adsorbents and catalysts, chromatographic supports and separators in microfluidic devices.