The presence of surfactants may have profound effects on the transport of organic contaminants in multiphase systems. It is a common practice, however, to model the subsurface migration of liquids independently of the aqueous phase composition. As such, transport in these systems may not be adequately characterized. This study investigates the impact of pH on interfacial tension, wettability, a...

In this paper, a new friction-induced nanofabrication method is presented to fabricate protrusive nanostructures on quartz surfaces through scratching a diamond tip under given normal loads. The nanostructures, such as nanodots, nanolines, surface mesas and nanowords, can be produced on the target surface by programming the tip traces according to the demanded patterns. The height of these nano...

[1] The interfacial interaction between mineral surfaces and immiscible fluids determines the efficiency of enhanced oil or gas recovery operations as well as our ability to inject and store CO2 in geological formations. Previous studies have shown that the interfacial tension and contact angle in CO2‐water‐mineral systems change noticeably with fluid pressure. We compile previous results and e...

We present a simple and computationally efficient classical atomistic model of silica in which the silicon and oxygen are simulated as hard spheres with four and two association sites, respectively. We have performed isobaric-isothermal Monte Carlo simulations to study the mechanical and phase behavior of this model. We have investigated solid phase structures of the model corresponding to quar...

Ž . High-purity aligned multi-walled carbon nanotubes MWNTs were synthesized through the catalytic decomposition of a ferrocene–xylene mixture at ;6758C in a quartz tube reactor and over quartz substrates, with a conversion of ;25% of the total hydrocarbon feedstock. Under the experimental conditions used, scanning electron microscope images reveal that the MWNT array grows perpendicular to the...

The transformation of quartz to stishovite has been studied by X-ray and optical examination of a series of experimentally shock-loaded specimens of a quartz-copper mixture. Shock pressures of 68 to 260 kb and peak temperatures of 320 ø to 870øK wer e achieved. Stishovite was identified from quartz shock-loaded above 90 kb; the quantity increases with increasing pressure, but is not dependent o...

A low-destructive friction-induced nanofabrication method is proposed to produce three-dimensional nanostructures on a quartz surface. Without any template, nanofabrication can be achieved by low-destructive scanning on a target area and post-etching in a KOH solution. Various nanostructures, such as slopes, hierarchical stages and chessboard-like patterns, can be fabricated on the quartz surfa...

Piezoelectric (strain) coefficients dij of quartz are calculated in terms of molecular dynamics as a function of pressure and temperature. We review the necessary formulas for the computation of electromechanical materials coefficients obtained at constant stress and temperature, and discuss how to overcome complications of the definition of polarization variations due to fluctuating box geomet...

The resistivities of specimens ofSi02 (fused quartz) singly and doubly shocked in the 10-45 and 27-90 GPa ranges, respectively, demonstrate a marked decrease from values of10-0.1 11-m at a single-shock pressure of -40 and a double-shock pressure of 7 4 G Pa. These states correspond to calculated shock temperatures of3300 and -3600 K, respectively. At shock pressures below 36 GPa the measured re...