Silica Nanoparticle Wettability: Characterization and Effects on the Emulsion Properties

Abstract

Recent interest in the use of nanoparticles in emulsion stabilization has driven increased efforts to understand how the characteristics of the particles influence the emulsion properties. While it is clear that the contact angle and wettability must play significant roles in determining the type of emulsion formed, it is not straightforward to measure the contact angle of a nanoparticle. In this paper, we compare multiple techniques for characterizing the water–air contact angle of silica nanoparticles while systematically varying the hydrophobicity of the nanoparticles using silanization. We then compare the performance of the particles in decane/water emulsions. While the heat of immersion measured by microcalorimetry is found to provide the best method for discriminating between the wettability of the particles, the fraction of surface covered by the silane groups was observed to affect the structure of the emulsion more profoundly than the differences in the contact angles of the particles. Furthermore, we find that the phase of initial dispersion is extremely influential in determining the resulting emulsion type and droplet size.

Effect of Various Silica Nanofluids: Reduction of Fines Migrations and Surface Modification of Berea Sandstone

“…The grafting of silanes on NP leads to steric stabilization. The surface modification was performed based on the method described by Weston, Jentoft, Grady, Resasco and Harwell [19]. 10 g of silica NP was dispersed in 100 mL toluene by probe sonication.…”

“…Agglomeration can lead to blockage of micro channels, formation damage, hinder the transport of NP and the displacing fluid in the reservoir. The main strategies utilized to enhance the stability of nanofluids are: (a) electrostatic stabilization [16] (by varying pH of the nanofluids); (b) employing stabilizing fluid/surfactant [17]; (c) surface modification [18,19] (functionalization) of the NP. Electrostatic stabilization (for example by varying the pH) is expected to fail in the presence of dissolved salts in brines.…”

“…Yang and Liu [18] presented a work on the synthesis of functionalized silica (SiO 2 ) NP by grafting silanes directly to the surface of silica NP which showed good stability. Weston, Jentoft, Grady, Resasco and Harwell [19] systematically performed surface modification of silica with different silanes and studied the wettability of the modified nanomaterials. However, it is essential to examine the effect these stabilization strategies have on the effectiveness of the nanofluids.…”

Novel continuous process for methacrolein production in numerous droplet reactors

“…Zhou et al used robust and recyclable amphiphilic SiO 2 with alkyl and propylsulfonic acid groups to rapidly and efficiently catalyze the acetalization of immiscible long‐chain fatty aldehydes with ethylene glycol 31 . In addition, many studies have focused on the stability and formation mechanism of Pickering emulsions 32,33 . Solid particles must have the ability to adsorb on the phase interface, so affinity to water and oil phase is of great importance.…”

Wettability Modification of Lignite by Adsorption of Dodecyl Based Surfactants for Inhibition of Moisture Re‐adsorption

“…As one more accurate experimental method, microcalorimetry was used to measure wetting heat of lignite in water which could characterize surface wettability better even by subtle difference than contact angle [21,22]. Wetting heat DH (J/g) of lignite before and after adsorbing surfactants were measured using a C80 calorimeter (Setaram, France) with the sensibility of 0.10 lW.…”