Thermodynamics of Ionization of Fluoroalcohols in Aqueous Solution: Hexafluoropropan-2-ol and Hexafluoropropan-2,2-diol

1971 ◽  
Vol 49 (18) ◽  
pp. 3054-3056 ◽  
Author(s):  
Earl M. Woolley ◽  
Loren G. Hepler ◽  
Rodney S. Roche
Keyword(s):  
Aqueous Solution ◽  
Solvent Interactions ◽  
Calorimetric Measurements ◽  
The Difference ◽  
Thermodynamics Of Ionization

Calorimetric measurements have led to ΔH0 = 6.37 kcal mol−1 for ionization of aqueous hexafluoro-propan-2-ol (HFIP) and to ΔH0 = 6.00 kcal mol−1 for ionization of aqueous hexafluoropropan-2,2-diol (HFPD). We have combined these values with our ΔG0 values from pK = 9.42 for HFIP and pK = 6.65 for HFPD to obtain ΔS0 = −21.7 cal deg−1 mol−1 for ionization of aqueous HFIP and ΔS0 = −10.3 cal deg−1 mol−1 for ionization of aqueous HFPD. These results (all for 298 °K) show that most of the difference in pK values is due to the large difference in entropy of ionization. The ΔS0 values can be explained largely in terms of solute-solvent interactions.

Thermodynamics of ionization of aqueous alkanolamines

1987 ◽  
Vol 65 (8) ◽  
pp. 1726-1728 ◽  
Author(s):  
Jin-Ho Kim ◽  
Celina Dobrogowska ◽  
Loren G. Hepler
Keyword(s):  
Aqueous Solution ◽  
Glass Electrode ◽  
Electrochemical Measurements ◽  
Calorimetric Measurements ◽  
Protonated Species ◽  
Thermodynamics Of Ionization

We have made electrochemical measurements with a glass electrode that have yielded pK values at T = 298.15 K for monothanolamine (MEA), triethanolamine (TEA), diisopropanolamine (DIPA), and methyldiethanolamine (MDEA) relative to the already well-known pK for diethanolamine (DEA), with all pK values referring to equilibria of the type AmH+(aq) = Am(aq) + H+(aq) in which Am(aq) represents an alkanolamine in aqueous solution and AmH+(aq) represents the corresponding protonated alkanolamine. We have also made calorimetric measurements leading to ΔH0 values for dissociation of the protonated species of all five of these alkanolamines in aqueous solution at T = 298.15 K. These pK and ΔH0 values have led to ΔG0 and ΔS0 values for the corresponding dissociation reactions of all five AmH+(aq) species.

Beneficiation of Seafloor Massive Sulfides by Liquid-Liquid Extraction

2021 ◽  
pp. 1-35
Author(s):  
Yasuharu Nakajima ◽  
Yuta Yamabe ◽  
Toyohisa Fujita ◽  
Gjergj Dodbiba
Keyword(s):  
Aqueous Solution ◽  
Contact Angle ◽  
High Pressures ◽  
Sulfide Mineral ◽  
Contact Angles ◽  
Liquid Extraction ◽  
Massive Sulfides ◽  
Liquid Liquid Extraction ◽  
Pressure Extraction ◽  
The Difference

Abstract This paper addresses the applicability of liquid-liquid extraction for separating mineral particles by the difference in oil-water partition coefficient, for the seafloor mineral processing of Seafloor Massive Sulfides (SMSs). Measurements of contact angle of sulfide mineral – aqueous solution – oil systems under high-pressure conditions were performed to evaluate the efficiency of liquid-liquid extraction at high pressures. The results showed that the contact angle stayed around 80 - 100° at the pressure range up to 16MPa; and the changes in the contact angles were within 5° with varying pressure. Extraction experiments were carried out by using particles of an SMS ore, which contained Zinc (Zn), Lead (Pb), and Barium (Ba) in the grade of more than 10 mass% and Copper (Cu) in a small percentage, to evaluate the beneficiation performance of liquid-liquid extraction. In the experiments, extraction conditions such as the dosage of chemical reagents, and pH in the aqueous solution were varied to optimize both the recovery and selectivity of Cu, Zn, and Pb in the oil phase, and those of Ba in the water phase. The experimental results showed that the optimum condition was 200 g/t dosage - pH 7, where the grade and recovery were ca. 37 mass% and ca. 90 mass%, respectively. The beneficiation performance of liquid-liquid extraction would be comparable to that of flotation, adapted to the processing of other SMS ores.

The cation and anion bonding modes make the difference: an unprecedented layered structure and a tri(hetero)nuclear moiety in thioantimonates(V)

2021 ◽  
Author(s):  
Wolfgang Bensch ◽  
Tobias Engesser ◽  
Christian Nather ◽  
Dario Broich ◽  
Felix Danker
Keyword(s):  
Aqueous Solution ◽  
Layered Structure ◽  
Room Temperature ◽  
The Difference

Mixing solutions of M2+ (M = Cu2+ or Zn2+) salts containing cyclam (cyclam = 1,4,8,11-tetraazacyclotetradecane) as ligand and an aqueous solution of Na3SbS4·9H2O at room temperature afforded crystallization of two...

Two physical processes enhanced the performance of Auricularia auricula dreg in Cd(II) adsorption: composting and pyrolysis

2019 ◽  
Vol 79 (8) ◽  
pp. 1511-1526
Author(s):  
Yue Li ◽  
Siqi Huang ◽  
Yingnan Wei ◽  
Xuesheng Liu ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Structure ◽  
Functional Groups ◽  
Exchange Capacity ◽  
Bet Surface Area ◽  
Order Kinetic ◽  
Auricularia Auricula ◽  
The Difference ◽  
The Impact ◽  
Crystal Species

Abstract This study aims to discover the impact of composting and pyrolysis on the adsorption performance of Auricularia auricula dreg (AAD) for Cd(II) in aqueous solution. Auricularia auricula dreg (AAD), Auricularia auricula dreg biochar (AADB) and Auricularia auricula dreg compost (AADC) were used to remove Cd(II) from aqueous solution, and their adsorption conditions and mechanisms were compared. The adsorption quantity of three adsorbents reached the maximum (AAD: 80.0 mg/g, AADB: 91.7 mg/g, AADC: 93.5 mg/g) under same conditions (adsorbent dosage of 1 g/L, pH 5.0, biosorption temperature of 25 °C, and biosorption time of 120 min). All Cd(II) biosorption processes onto three adsorbents complied with the Langmuir isotherm model and the pseudo-second-order kinetic equation, and spontaneously occurred in an order of AADC > AADB > AAD. The difference in biosorption quantity relied on variation in surface structure, crystal species and element content caused by composting or pyrolysis. Composting enhanced the changes in surface structure, crystal species, functional groups and ion exchange capacity of the AAD, resulting in AAD had greatly improved the biosorption quantity of Cd(II). Pyrolysis increased the adsorption of Cd(II) mainly by increasing the Brunauer–Emmett–Teller (BET) surface area, the particle size and pH, in the same time, providing more oxygen-containing functional groups.

scholarly journals Facile One-Pot Synthesis of Hyperbranched Glycopolymers in Aqueous Solution via a Hydroxy/Cu(III) Redox Process

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2065
Author(s):  
Feng Liu ◽  
Yuangong Zhang ◽  
Xiaohui Hao ◽  
Qian Zhou ◽  
Ying Zheng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Redox System ◽  
Hen Egg White Lysozyme ◽  
One Pot ◽  
Oh Groups ◽  
Egg White Lysozyme ◽  
Hyperbranched Poly ◽  
Amyloid Fibrillation ◽  
Hen Egg White ◽  
The Difference

In this study, a self-condensing vinyl copolymerization/redox (SCVP/Redox) system was constructed to prepare hyperbranched poly(methyl-6-O-methacryloyl-α-D-glucoside) by using Cu(III) as the initiator in aqueous solution, in which the –OH group in C-2, C-3 and C-4 position on pyranose rings could be initiated by Cu(III). The branched and linear units were clearly distinguished by nuclear magnetic resonance (1H NMR) to estimate the degree of branching (DB). When the ratio of Cu(III) to monomer fixed at 0.5:1, the DB value reached 0.32, which was higher than the product initiated by Ce(IV). Moreover, the inhibition activity of the products on amyloid fibrillation was investigated by using the hen egg-white lysozyme (HEWL) as a model based on the difference of the initiation sites. The results showed that the –OH groups in C-4 position might play an important role in this process.

Interaction Between Two Falling Droplets in the Liquid-Liquid Two Phase Flow

2011 ◽  
Author(s):  
Nao Ninomiya ◽  
Takeshi Mori
Keyword(s):  
Aqueous Solution ◽  
Multiphase Flow ◽  
Physical Mechanism ◽  
Two Phase Flow ◽  
Refractive Indices ◽  
Phase Flow ◽  
Two Phase ◽  
Piv Measurement ◽  
The Difference ◽  
Simultaneous Visualization

Although the phenomena related to the multiphase flow can be found in many kinds of industrial and engineering applications, the physical mechanism of the multiphase flow has not been investigated in detail. The major reason for the lack of data in the multiphase flow lies in the difficulties in measuring the flow quantities of the multiple phases simultaneously. The difference in the refractive indices makes the visualization in the vicinity of the boundary of the multiple phases almost impossible. In this study, the refractive index of the aqueous phase has been equalized to that of the oil phase by adjusting the concentration of aqueous solution. Presently, the simultaneous visualization and the PIV measurement have been carried out about the both phases of the liquid-liquid two-phase flow. The measurement has been carried out for the flow field around and inside of two falling droplets interacting each other while they travel.

Sign in / Sign up

Export Citation Format

Share Document