Raman spectroscopy study on the dynamic behavior of nitrate anion in zinc nitrate solution at high temperatures and pressure

Aqueous hybrids of amino-functionalized nanosilica and acrylamide-based polymer for enhanced oil recovery

Amino-functionalized nanosilica (ANS) was prepared using nanosilica (NS) and 3-aminopropyltriethoxysilane (APTES) aiming to reinforce the interaction between nanoparticles and polymer molecules. The copolymer of acrylamide, 2-acrylamido-2-methyl-1-propane sulfonic acid (PM), and four ANS samples with different NS to APTES ratios were synthesized. A series of nanoparticle/polymer hybrid systems were fabricated by introducing NS or ANS suspension into PM aqueous solution. The rheological properties and surface activities of these hybrid systems were studied in comparison with PM. The results indicate that the salt-tolerance and heat-resistance properties of PM solution were improved by the introduction of ANS particles. Moreover, the structures of ANS samples have a significant effect on the effectiveness of the nanoparticles due to the fact that the amine group density on the ANS surface can affect the strength of intermolecular interaction between nanoparticles and polymer molecules. Additionally, the better ability of the ANS sample with proper amine group density showed in reducing the oil/water interfacial tension over NS and other ANS samples made it a more promising chemical for enhancing oil recovery. The results from core flooding tests show that the PM/ANS system has the greatest oil recovery factor (16.30%), while the values for PM/NS and PM are 10.84% and 6.00%, respectively.

The amino-functionalized nanosilica/polymer hybrid systems have better salt tolerance and EOR performance than unmodified nanosilica polymer hybrid systems.

High-temperature and high-pressure cubic zirconia anvil cell for Raman spectroscopy

A simple and inexpensive cubic zirconia anvil cell has been developed for the performance of in situ Raman spectroscopy up to the conditions of 500 degrees C and 30 kbar pressure. The design and construction of this cell are fully described, as well as its applications for Raman spectroscopy. Molybdenum heater wires wrapped around ceramic tubes encircling two cubic zirconia anvils are used to heat samples, and the temperatures are measured and controlled by a Pt-PtRh thermocouple adhered near the sample chamber and an intelligent digital control apparatus. With this cell, Raman spectroscopic measurements have been satisfactorily performed on water at 6000 bar pressure to 455 degrees C and on ice of room temperature to 24 kbar, in which the determinations of pressures make use of changes of the A1 Raman modes of quartz and the shift of the sharpline (R-line) luminescence of ruby, respectively.

Advances with supercritical fluids

In the last decade, supercritical fluids more and more have been proved as environmentally benign media for chemical and related processes. Many new processes and products have been developed, using the inherent physical and chemical properties of supercritical fluids. Moreover, these processes also promise economic effects. The prerequisites for this success however, are a sound knowledge of physico-chemical properties of--and phenomena in--supercritical mixtures and the availability of other chemical engineering data. This requires an effective exchange of knowledge between a large number of branches of science. In the following, a lot of recent papers will be cited, which should give an overview of actual results on fundamentals and their applications.