Organic Reactions and Nanoparticle Preparation in CO<sub>2</sub>‐Induced Water/P104/<i>p</i>‐Xylene Microemulsions

Zhang, Rui; Li, Jun; Han, Buxing; Wu, Weize; Jiang, Tao; Liu, Zhimin; Du, Jimin

doi:10.1002/chem.200204496

Cited by 31 publications

(23 citation statements)

References 44 publications

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“…17 Specifically for the synthesis of nanoparticles, the benefits are apparent; firstly by making the process more environmentally benign, and secondly facilitating the facile recovery of nanomaterials after the reaction has taken place by merely reducing the pressure and releasing the gas. A good example of the benefits of incorporating supercritical CO 2 into this process has been shown by Zhang et al 136 Xylene is an inadequate solvent to stabilize a microemulsion of water/P104/xylene in presence of CO 2 at ambient pressure (P104:…”

Section: Water In Sc-fluid Microemulsionsmentioning

confidence: 99%

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Recent advances in nanoparticle synthesis with reversed micelles

Eastoe

Hollamby

Hudson

2006

Advances in Colloid and Interface Science

581

408

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Section: Water In Sc-fluid Microemulsionsmentioning

confidence: 99%

“…anti-solvent, 79,136,158 flocculation by use of a photolyzable surfactant 76,159 or temperature induced separation, 160,161 but at the time of writing this remains a young field and interesting developments can be anticipated. …”

Section: Significant Recent Highlightsmentioning

confidence: 99%

Recent advances in nanoparticle synthesis with reversed micelles

Eastoe

Hollamby

Hudson

2006

Advances in Colloid and Interface Science

581

408

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“…CO 2 solubility is a necessary but insufficient property of the candidate surfactant. The interactions 115 between the tail and CO 2 must be strong enough to impart CO 2 -philicity to a compound that contains a CO 2 -phobic segment.…”

Section: Design Of Oxygenated Hydrocarbon and Hydrocarbon-based Co 2 mentioning

confidence: 99%

Synthesis and Evaluation of CO2 Thickeners Designed with Molecular Modeling

Enick¹,

Beckman²,

Johnson³

2009

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The objective of this research was to use molecular modeling techniques, coupled with our prior experimental results, to design, synthesize and evaluate inexpensive, non-fluorous carbon dioxide thickening agents.The first type of thickener that was considered was associating polymers. Typically, these thickeners are copolymers that contain a highly CO 2 -philic monomer, and a small concentration of a CO 2 -phobic associating monomer.Yale University was solely responsible for the synthesis of a second type of thickener; small, hydrogen bonding compounds. These molecules have a core that contains one or more hydrogen-bonding groups, such as urea or amide groups. Non-fluorous, CO 2 -philic functional groups were attached to the hydrogen bonding core of the compound to impart CO 2 stability and macromolecular stability to the linear "stack" of these compounds.The third type of compound initially considered for this investigation was CO 2 -soluble surfactants. These surfactants contain conventional ionic head groups and composed of CO 2 -philic oligomers (short polymers) or small compounds (sugar acetates) previously identified by our research team. Mobility reduction could occur as these surfactant solutions contacted reservoir brine and formed mobility control foams in-situ.The vast majority of the work conducted in this study was devoted to the copolymeric thickeners and the small hydrogen-bonding thickeners; these thickeners were intended to dissolve completely in CO 2 and increase the fluid viscosity. A small but important amount of work was done establishing the groundwork for CO 2 -soluble surfactants that reduced mobility by generating foams in-situ as the CO 2 +surfactant solution mixed with in-situ brine. PolymersIn this final report, we review our entire co-polymeric thickener effort and detail, for the first time, the phase behavior and viscosity results of the first non-fluorous, oxygenated hydrocarbon-based, associating polymer CO 2 thickener, poly(vinyl acetate -co -benzoyl 5% ). The CO 2 -philic monomer was vinyl acetate, and the associative thickener monomer was vinyl benzoate. Poly(vinyl acetate -co -benzoyl 5% ), Mw ~ 12000, is capable of increasing the viscosity of CO 2 by 70% at a concentration of 2wt%, a shear rate of ~5000s -1 , 298K and 9500 psia. Unfortunately, poly(vinyl acetate -co -benzoyl 5% ) is not capable of dissolving in CO 2 at pressures close to the MMP, roughly 1200 psia at 298 K. In fact, we are now convinced that a non-fluorous, hydrocarbon-based copolymeric thickener cannot be designed that will dissolve in CO 2 at typical reservoir conditions. Why? Every polymer that we designed using molecular modeling tools was indeed CO 2 soluble, a somewhat remarkable achievement given the small number of CO 2 soluble surfactants that have ever been identified, but each one was less soluble in CO 2 than poly(vinyl acetate). Therefore co-polymeric thickeners based on any CO 2 soluble polymer will undoubtedly be less soluble in CO 2 (i.e. require even greater pressures than 9500 psia)...

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“…Therefore, an interested reader surveying the scientific literature quickly comes to realize that there is a great strength and depth of knowledge about synthesis of NPs. On the other hand there is a surprising gap in understanding about recovery and recycling of dispersed nanoparticles, which feature in a much smaller fraction of articles, for example water-induced separation [20], temperature induced recovery [21,22], precipitation by anti-solvents [23][24][25], centrifugation [26], cloud point extraction [27] or flocculation by utilizing photolyzable surfactants [28,29]. Of course, if the NPs are made from high value precursors, such as precious metals, then processing, recovery and recycling impacts on the economics of any potential NP applications.…”

Section: Introductionmentioning

confidence: 99%