Interfacial Rheology of an Ultrathin Nanocrystalline Film Formed at the Liquid/Liquid Interface

Abstract

We report the interfacial properties of monolayers of Ag nanoparticles 10-50 nm in diameter formed at the toluene-water interface under steady as well as oscillatory shear. Strain amplitude sweep measurements carried out on the film reveal a shear thickening peak in the loss moduli (G") at large amplitudes followed by a power law decay of the storage (G') and loss moduli with exponents in the ratio 2:1. In the frequency sweep measurements at low frequencies, the storage modulus remains nearly independent of the angular frequency, whereas G" reveals a power law dependence with a negative slope, a behavior reminiscent of soft glassy systems. Under steady shear, a finite yield stress is observed in the limit of shear rate .gamma going to zero. However, for .gamma > 1 s-1, the shear stress increases gradually. In addition, a significant deviation from the Cox-Merz rule confirms that the monolayer of Ag nanoparticles at the toluene-water interface forms a soft two-dimensional colloidal glass.

Influence of the contact angle of silica nanoparticles at the air–water interface on the mechanical properties of the layers composed of these particles

“…Both present a maximum at intermediate SiOH content. For particles of 34% SiOH, the yield strain γ Y is quite high at 5%, much higher than that of < 1% for silver nanoparticles adsorbed at an oil-water interface [30]. However, it is close to that of monolayers of insoluble surfactants and proteins [31,32].…”

Voltammetry of Ion Transfer at a Water–Toluene Micro‐ Interface

“…The interface between Wa nd an aromatic hydrocarbon such as toluene is utilized in solvente xtraction, [23,24] and over the past several decades the formation of nanoparticles and thin-layer films at the W j toluene interface has been studied extensive-ly. [25][26][27][28][29][30] To the best of our knowledge,h owever,t here are no direct experimental data on VITIES at the W j toluene interface.Use of am icro-electrode and tetrahexylammonium perchlorate (THexA + ClO 4 À )a st he SE enablet he observation of the reversible response for the redox reaction of ferrocene [31] or porphyrins [32,33] in toluene, because the micro-electrode reduces the effect of the ohmic drop. The effect of the addition of the RTIL [trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate, aph4.cph12]t ot oluene has been demonstratedi nahomogeneous electrochemical system using macro-disc electrodes, and it was observed that 0.4 m (m = mol dm À3 )a ph4.cph12 in toluene induces conductivity in the toluene solutiona ta mbient temperature.…”

“…The interface between Wa nd an aromatic hydrocarbon such as toluene is utilized in solvente xtraction, [23,24] and over the past several decades the formation of nanoparticles and thin-layer films at the W j toluene interface has been studied extensive-ly. [25][26][27][28][29][30] To the best of our knowledge,h owever,t here are no direct experimental data on VITIES at the W j toluene interface.…”

Deposition of Ag and Ag–Au nanocrystalline films with tunable conductivity at the water–toluene interface

“…54 Both Efrima and Rao have reported the synthesis and properties of silver lms that have been at the interface between two immiscible liquids using other precursors. 55,56 The charge transport characteristics of these lms are unknown.…”