Entropy−Enthalpy Compensations in Solutions of Dual Character Molecules with Polymeric Chromatographic Liquid Phases

2005 ◽  
Vol 109 (5) ◽  
pp. 1736-1743 ◽  
Author(s):  
Jan-Chan Huang ◽  
Richard J. Sheehan ◽  
Stanley H. Langer
Keyword(s):  
Liquid Phases ◽  
Dual Character

In Memoriam. Professor Stefan ERNST

2015 ◽  
Vol 39 (4) ◽  
pp. 665-666
Author(s):  
Mirosław Chorazewski
Keyword(s):  
Secondary Education ◽  
Primary Education ◽  
Unexpected Death ◽  
Uranyl Compounds ◽  
Liquid Phases ◽  
German Speaking ◽  
In Memoriam ◽  
The University ◽  
Phd Thesis ◽  
Molecular Acoustics

Abstract It is with great sadness that we inform our readers about the recent death of Professor Stefan Ernst. Stefan Ernst was born in Piaśniki, Upper Silesia, on November 03, 1934, to parents of Polish-German descent. His primary education started during the war at a German-speaking school in Wirek and continued in Olesno, where he also got his secondary education. As chemistry studies were not yet available at the University ofWrocław in 1953, he started studying biology and switched to chemistry a year later. He received his master’s degree in chemistry in 1959, as one of the first graduates in that major. Then, he started his work on application of thermodynamics and molecular acoustics in investigation of liquid phases under the guidance of the Prof. Bogusława Jeżowska-Trzebiatowska. On 28 November 1967, he defended his PhD thesis entitled “Association-Dissociation Equilibria and the Structure of Uranyl Compounds in Organic Solvents” at the University of Wrocław. Professor Stefan Ernst was a linguist, a polyglot, a renowned thermodynamisist and a researcher of molecular acoustics. With great regret and shock we have learned of his sudden and unexpected death on August 03, 2014, in a hospital in Kraków.

Wide-range equations of state for organic liquids

2007 ◽  
Vol 5 ◽  
pp. 113-120 ◽  
Author(s):  
R.Kh. Bolotnova
Keyword(s):  
High Pressures ◽  
Equations Of State ◽  
Organic Liquids ◽  
Liquid Phases ◽  
Wide Range ◽  
High Pressures And Temperatures

The method of construction the wide-range equations of state for organic liquids, describing the gas and liquid phases including dissociation and ionization which occurs during an intense collapse of steam bubbles and accompanied by ultra-high pressures and temperatures, is proposed.

Isomorphic Co-Crystallization of Ammonium and Rubidium Bromocarnallites

1994 ◽  
Vol 59 (8) ◽  
pp. 1815-1819 ◽  
Author(s):  
Christomir Christov ◽  
Christo Balarew ◽  
Stefka Tepavitcharova
Keyword(s):  
Distribution Coefficients ◽  
Mixed Crystals ◽  
Solubility Isotherm ◽  
Continuous Series ◽  
Liquid Phases

The solubility isotherm of the system NH4Br.MgBr2.6 H2O - RbBr.MgBr2.6 H2O - H2O has been investigated at 75 °C and formation of a continuous series of mixed crystals is established. The factors determining the values of the distribution coefficients of the components between the crystalline and liquid phases are discussed.

Heat capacities and enthalpies of fusion and transformation for solvates of some salts with dimethyl sulfoxide and dimethylformamide

1988 ◽  
Vol 53 (12) ◽  
pp. 3072-3079
Author(s):  
Mojmír Skokánek ◽  
Ivo Sláma
Keyword(s):  
Heat Capacity ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Dimethyl Sulfoxide ◽  
Liquidus Temperature ◽  
Molar Heat Capacity ◽  
Solid Phase ◽  
Zinc Nitrate ◽  
Heat Capacities ◽  
Liquid Phases

Molar heat capacities and molar enthalpies of fusion of the solvates Zn(NO3)2 . 2·24 DMSO, Zn(NO3)2 . 8·11 DMSO, Zn(NO3)2 . 6 DMSO, NaNO3 . 2·85 DMSO, and AgNO3 . DMF, where DMSO is dimethyl sulfoxide and DMF is dimethylformamide, have been determined over the temperature range 240 to 400 K. Endothermic peaks found for the zinc nitrate solvates below the liquidus temperature have been ascribed to solid phase transformations. The molar enthalpies of the solid phase transformations are close to 5 kJ mol-1 for all zinc nitrate solvates investigated. The dependence of the molar heat capacity on the temperature outside the phase transformation region can be described by a linear equation for both the solid and liquid phases.

scholarly journals Double-Chain Cationic Surfactants: Swelling, Structure, Phase Transitions and Additive Effects

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3946
Author(s):  
Rui A. Gonçalves ◽  
Yeng-Ming Lam ◽  
Björn Lindman
Keyword(s):  
Phase Transitions ◽  
Phase Behaviour ◽  
Double Chain ◽  
Scanning Calorimetry ◽  
Alkyl Chains ◽  
X Ray Scattering ◽  
Amphiphilic Compounds ◽  
Liquid Phases ◽  
Lamellar Phases ◽  
Water Layers

Double-chain amphiphilic compounds, including surfactants and lipids, have broad significance in applications like personal care and biology. A study on the phase structures and their transitions focusing on dioctadecyldimethylammonium chloride (DODAC), used inter alia in hair conditioners, is presented. The phase behaviour is dominated by two bilayer lamellar phases, Lβ and Lα, with “solid” and “melted” alkyl chains, respectively. In particular, the study is focused on the effect of additives of different polarity on the phase transitions and structures. The main techniques used for investigation were differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS and WAXS). From the WAXS reflections, the distance between the alkyl chains in the bilayers was obtained, and from SAXS, the thicknesses of the surfactant and water layers. The Lα phase was found to have a bilayer structure, generally found for most surfactants; a Lβ phase made up of bilayers with considerable chain tilting and interdigitation was also identified. Depending mainly on the polarity of the additives, their effects on the phase stabilities and structure vary. Compounds like urea have no significant effect, while fatty acids and fatty alcohols have significant effects, but which are quite different depending on the nonpolar part. In most cases, Lβ and Lα phases exist over wide composition ranges; certain additives induce transitions to other phases, which include cubic, reversed hexagonal liquid crystals and bicontinuous liquid phases. For a system containing additives, which induce a significant lowering of the Lβ–Lα transition, we identified the possibility of a triggered phase transition via dilution with water.

Liquid Phases Used in Packed Gas Chromatographic Columns. Part I. Polysiloxane Liquid Phases

1985 ◽  
Vol 23 (4) ◽  
pp. 161-167 ◽  
Author(s):  
J. A. Yancey
Keyword(s):  
Chromatographic Columns ◽  
Liquid Phases

scholarly journals Palladium and Copper: Advantageous Nanocatalysts for Multi-Step Transformations

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1891
Author(s):  
Antonio Reina ◽  
Trung Dang-Bao ◽  
Itzel Guerrero-Ríos ◽  
Montserrat Gómez
Keyword(s):  
Chemical Properties ◽  
Added Value ◽  
Solid Supports ◽  
Nanosized Materials ◽  
Nano Structures ◽  
Liquid Phases ◽  
Wide Range ◽  
Synthetic Methodologies ◽  
Physical And Chemical ◽  
A Current

Metal nanoparticles have been deeply studied in the last few decades due to their attractive physical and chemical properties, finding a wide range of applications in several fields. Among them, well-defined nano-structures can combine the main advantages of heterogeneous and homogenous catalysts. Especially, catalyzed multi-step processes for the production of added-value chemicals represent straightforward synthetic methodologies, including tandem and sequential reactions that avoid the purification of intermediate compounds. In particular, palladium- and copper-based nanocatalysts are often applied, becoming a current strategy in the sustainable synthesis of fine chemicals. The rational tailoring of nanosized materials involving both those immobilized on solid supports and liquid phases and their applications in organic synthesis are herein reviewed.

Experimental and DFT insights into nitrogen and sulfur co-doped carbon nanotubes for effective desulfurization of liquid phases: Equilibrium & kinetic study

2021 ◽  
Vol 15 (5) ◽  
Author(s):  
Seyyed Salar Meshkat ◽  
Ebrahim Ghasemy ◽  
Alimorad Rashidi ◽  
Omid Tavakoli ◽  
Mehdi Esrafili
Keyword(s):  
Carbon Nanotubes ◽  
Kinetic Study ◽  
Liquid Phases ◽  
Co Doped

scholarly journals THE DETERMINATION OF CAROTENE AND XANTHOPHYLL BY A SINGLE DISTRIBUTION BETWEEN LIQUID PHASES

1936 ◽  
Vol 113 (1) ◽  
pp. 89-104
Author(s):  
S.W. Clausen ◽  
A.B. McCoord
Keyword(s):  
Liquid Phases

Insights into Heap Bioleaching at the Agglomerate-Scale

2017 ◽  
Vol 262 ◽  
pp. 185-188 ◽  
Author(s):  
Alison Cox ◽  
Christopher G. Bryan
Keyword(s):  
Interstitial Cell ◽  
Cell Concentration ◽  
Low Grade ◽  
Dissolved Metals ◽  
Copper Ore ◽  
Cell Numbers ◽  
Liquid Phases ◽  
Heap Bioleaching ◽  
Cell Concentrations ◽  
The Difference

Previous agglomerate-scale heap bioleaching studies have outlined the variations in cell numbers of the liquid and attached phases during colonisation of sterilised ore by a pure culture. In this study, a mixed mesophilic culture was used in agglomerate-scale columns containing non-sterilised low-grade copper ore. Over a six - month period, columns were harvested at various intervals to provide snapshots of the metal distribution and the quantity, location, and ecological variations of mineral-oxidizing microbes within the ore bed. The initial colonisation period in this experiment was dissimilar to previous work, as the indigenous community was retained within the ore-bed throughout acid agglomeration. The overall colonisation phase lasted for approximately 1,000 hours until cell concentrations stabilised. In each column, less than 0.05% of the total cells were found in the leachate, 15-20% in the interstitial phase and the remaining ~80% were attached to the mineral surface. Once cell numbers had stabilised, interstitial cell concentrations were approximately 2,000× greater than those in the leachate. This difference persisted for the duration of the experiment. Copper concentrations in the two liquid phases generally decreased over time, but were on average 50× higher in the interstitial phase. Iron concentrations were more stable, but again were 30× higher in the interstitial phase. This demonstrates that that the difference in cell concentration between the leachate and interstitial phases cannot be explained through diffusion gradients within the system as it is much greater than those observed for the dissolved metals. It also shows that the specific environmental conditions of the interstitial and attached cells are very different to those inferred through analysis of leachates alone.

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