Picosecond dynamics of hydrogen bond rearrangements during phase separation of a triethylamine and water mixture

2014 ◽  
Vol 13 (6) ◽  
pp. 891-897 ◽  
Author(s):  
Shinji Kajimoto ◽  
Nak-Hyun Seong ◽  
Hiroshi Fukumura ◽  
Dana D. Dlott

A picosecond temperature jump experiment reveals that phase separation in a liquid triethylamine (TEA)–water mixture started from hydrogen bond scission of TEA–water aggregates in TEA-rich regions and then in water-rich regions.

1993 ◽  
Vol 26 (15) ◽  
pp. 4047-4049 ◽  
Author(s):  
Kyu Dae Kwak ◽  
Mamoru Okada ◽  
Tsuneo Chiba ◽  
Takuhei Nose

2019 ◽  
Vol 13 (2) ◽  
pp. 5163-5181
Author(s):  
Z. Q. Memon ◽  
W. Pao ◽  
F. Hashim ◽  
S. Ahmed

The experimental data for phase separation of the air-water mixture in a T-Junction with the expander section after the branch arm is presented in this work. The main and run arms of the T-junction are directed along the horizontal plane with the branch arm positioned in the vertical plane. The diameter of the main arm is 74 mm, with diameter ratio(s) of, 0.67, and 0.33 in relation to branch arm. At the inlet section of the T-junction, the flow regimes generated were stratified, stratified wavy and slug flow. At the inlet, the air and water superficial velocities are in the range of 0.25 - 0.140 m/s and 0.14-0.78 m/s respectively. The effect of the expander section after the branch arm, the air superficial velocity USA and water superficial velocity USw on liquid carryover (WL3/WL1)max in branch arm have been studied. Based on the experimental data obtained for T-junction with expander section, complete phase separation of air and water was observed in stratified and stratified wavy flow for all superficial velocities and improved phase separation for slug flow. In slug flow, increasing the liquid superficial velocity improves the phase separation but increasing the gas velocity decreases the phase separation. Finally, the volume weighted phase in this new T-junction design is compared with the phase separation data of a simple T-junction.


Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2761 ◽  
Author(s):  
Wenbin Chen ◽  
Siyuan Wu ◽  
Jianing Zhang ◽  
Fengjie Yu ◽  
Jianbo Hou ◽  
...  

In the present work, we developed a simple and rapid sample preparation method for the determination of neonicotinoid pesticides in honey based on the matrix-induced sugaring-out. Since there is a high concentration of sugars in the honey matrix, the honey samples were mixed directly with acetonitrile (ACN)-water mixture to trigger the phase separation. Analytes were extracted into the upper ACN phase without additional phase separation agents and injected into the HPLC system for the analysis. Parameters of this matrix-induced sugaring-out method were systematically investigated. The optimal protocol involves 2 g honey mixed with 4 mL ACN-water mixture (v/v, 60:40). In addition, this simple sample preparation method was compared with two other ACN-water-based homogenous liquid-liquid extraction methods, including salting-out assisted liquid-liquid extraction and subzero-temperature assisted liquid-liquid extraction. The present method was fully validated, the obtained limits of detection (LODs) and limits of quantification (LOQs) were from 21 to 27 and 70 to 90 μg/kg, respectively. Average recoveries at three spiked levels were in the range of 91.49% to 97.73%. Precision expressed as relative standard deviations (RSDs) in the inter-day and intra-day analysis were all lower than 5%. Finally, the developed method was applied for the analysis of eight honey samples, results showed that none of the target neonicotinoid residues were detected.


1992 ◽  
Vol 24 (2) ◽  
pp. 215-218 ◽  
Author(s):  
Mamoru Okada ◽  
Kyu Dae Kwak ◽  
Takuhei Nose

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 95 ◽  
Author(s):  
Michael Hu ◽  
Chaiwat Engtrakul ◽  
Brian Bischoff ◽  
Mi Lu ◽  
Mussie Alemseghed

Surface wettability-tailored porous ceramic/metallic membranes (in the tubular and planar disc form) were prepared and studied for both vapor-phase separation and liquid pervaporative separations of water-ethanol mixtures. Superhydrophobic nanoceramic membranes demonstrated more selective permeation of ethanol (relative to water) by cross-flow pervaporation of liquid ethanol–water mixture (10 wt % ethanol feed at 80 °C). In addition, both superhydrophilic and superhydrophobic membranes were tested for the vapor-phase separations of water–ethanol mixtures. Porous inorganic membranes having relatively large nanopores (up to 8-nm) demonstrated good separation selectivity with higher permeation flux through a non-molecular-sieving mechanism. Due to surface-enhanced separation selectivity, larger nanopore-sized membranes (~5–100 nm) can be employed for both pervaporation and vapor phase separations to obtain higher selectivity (e.g., permselectivity for ethanol of 13.9 during pervaporation and a vapor phase separation factor of 1.6), with higher flux due to larger nanopores than the traditional size-exclusion membranes (e.g., inorganic zeolite-based membranes having sub-nanometer pores). The prepared superhydrophobic porous inorganic membranes in this work showed good thermal stability (i.e., the large contact angle remains the same after 300 °C for 4 h) and chemical stability to ethanol, while the silica-textured superhydrophilic surfaced membranes can tolerate even higher temperatures. These surface-engineered metallic/ceramic nanoporous membranes should have better high-temperature tolerance for hot vapor processing than those reported for polymeric membranes.


2004 ◽  
Vol 33 (6/7) ◽  
pp. 721-732 ◽  
Author(s):  
Akihiro Wakisaka ◽  
Shunsuke Mochizuki ◽  
Hitomi Kobara

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