Solubility in the CuCl2-NaCl-H2O System and Hydration Analysis in the Case of Complexation

1999 ◽  
Vol 64 (8) ◽  
pp. 1262-1268 ◽  
Author(s):  
Jitka Eysseltová ◽  
Vladimír Zbranek ◽  
Jan Jirsák

The solubility diagram in the title system was studied at 25 °C. The results were compared with contradictional isotherms of other authors and one isotherm being in error was localized and rejected. The reliable solubility branches were treated with hydration analysis, which brings information on ionic processes in saturated solutions. Formation of coordination anions such as [CuCl3]- and [CuCl4]2- was found to be the main ionic process in saturated solutions in spite of the non-existence of the corresponding solid phase. The information obtained by this method for systems where hydration of components and complex formation take place simultaneously is demonstrated and discussed for the first time. A possibility of calculation of activity coefficients of the solute on both crystallization branches is discussed.

2019 ◽  
Author(s):  
Elena Prigorchenko ◽  
Sandra Kaabel ◽  
Triin Narva ◽  
Anastassia Baškir ◽  
Maria Fomitšenko ◽  
...  

Amplification of a thermodynamically unfavoured macrocyclic product through the directed shift of the equilibrium between dynamic covalent chemistry library members is difficult to achieve. We show for the first time that during condensation of formaldehyde and <i>cis</i>-<i>N,N'</i>-cyclohexa-1,2-diylurea formation of <i>inverted-cis</i>-cyclohexanohemicucurbit[6]uril (<i>i-cis</i>-cycHC[6]) can be induced at the expense of thermodynamically favoured <i>cis</i>-cyclohexanohemicucurbit[6]uril (<i>cis</i>-cycHC[6]). The formation of <i>i-cis-</i>cycHC[6] is enhanced in low concentration of the templating chloride anion and suppressed in excess of this template. We found that reaction selectivity is governed by the solution-based template-aided dynamic combinatorial chemistry and continuous removal of the formed cycHC[6] macrocycles from the equilibrating solution by precipitation. Notably, the <i>i-cis</i>-cycHC[6] was isolated with 33% yield. Different binding affinities of three diastereomeric <i>i-cis</i>-, <i>cis</i>-cycHC[6] and their chiral isomer (<i>R,R</i>)-cycHC[6] for trifluoroacetic acid demonstrate the influence of macrocycle geometry on complex formation.


2018 ◽  
Vol 25 (6) ◽  
pp. 1157-1165
Author(s):  
Taoufik Mnasri ◽  
Adel Abbessi ◽  
Rached Ben Younes ◽  
Atef Mazioud

AbstractThis work focuses on identifying the thermal conductivity of composites loaded with phase-change materials (PCMs). Three configurations are studied: (1) the PCMs are divided into identical spherical inclusions arranged in one plane, (2) the PCMs are inserted into the matrix as a plate on the level of the same plane of arrangement, and (3) the PCMs are divided into identical spherical inclusions arranged periodically in the whole matrix. The percentage PCM/matrix is fixed for all cases. A comparison among the various situations is made for the first time, thus providing a new idea on how to insert PCMs into composite matrices. The results show that the composite conductivity is the most important consideration in the first case, precisely when the arrangement plane is parallel with the flux and diagonal to the entry face. In the present work, we are interested in exploring the solid-solid PCMs. The PCM polyurethane and a wood matrix are particularly studied.


RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41862-41868 ◽  
Author(s):  
Maosheng Zhang ◽  
Guobin Huang ◽  
Jiarong Huang ◽  
Ling Zhong ◽  
Weilan Chen

Novel octahedral structured Fe3O4@SiO2@polydimethylsiloxane magnetic nanoparticles (Fe3O4@SiO2@PDMS MNPs) have been successfully synthesized for the first time.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2869 ◽  
Author(s):  
Iván Taima-Mancera ◽  
Priscilla Rocío-Bautista ◽  
Jorge Pasán ◽  
Juan Ayala ◽  
Catalina Ruiz-Pérez ◽  
...  

Four metal-organic frameworks (MOFs), specifically UiO-66, UiO-66-NH2, UiO-66-NO2, and MIL-53(Al), were synthesized, characterized, and used as sorbents in a dispersive micro-solid phase extraction (D-µSPE) method for the determination of nine pollutants of different nature, including drugs, phenols, polycyclic aromatic hydrocarbons, and personal care products in environmental waters. The D-µSPE method, using these MOFs as sorbents and in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD), was optimized. The optimization study pointed out to UiO-66-NO2 as the best MOF to use in the multi-component determination. Furthermore, the utilization of isoreticular MOFs based on UiO-66 with the same topology but different functional groups, and MIL-53(Al) to compare with, allowed us for the first time to evaluate the influence of such functionalization of the ligand with regards to the efficiency of the D-µSPE-HPLC-DAD method. Optimum conditions included: 20 mg of UiO-66-NO2 MOF in 20 mL of the aqueous sample, 3 min of agitation by vortex and 5 min of centrifugation, followed by the use of only 500 µL of acetonitrile as desorption solvent (once the MOF containing analytes was separated), 5 min of vortex and 5 min of centrifugation. The validation of the D-µSPE-HPLC-DAD method showed limits of detection down to 1.5 ng·L−1, average relative recoveries of 107% for a spiked level of 1.50 µg·L−1, and inter-day precision values with relative standard deviations lower than 14%, for the group of pollutants considered.


Author(s):  
I. V. Yakovleva ◽  
E. A. Kurbatova ◽  
E. A. Akhmatova ◽  
E. V. Sukhova ◽  
D. V. Yashunsky ◽  
...  

Aim. Production of monoclonal antibodies (mAb) to synthetic tetrasaccharide - repeating unit of the capsular polysaccharide (CP) of Streptococcus pneumoniae serotype 14 and their immunochemical characterization. Materials and methods. In order to generate the hybridoma producing mAb, mice were immunized with synthetic tetrasaccharide conjugated with bovine serum albumin (BSA) with following hybridization of B lymphocytes with mouse myeloma cells. Antibodies were obtained in vitro andin vivo. Immunochemical characterization of mAb to tetrasaccharide was carried out using a variety of ELISA options. Results. For the first time obtained mouse hybridoma, producing IgM to tetrasacchride. The IgM titer of anti-tetrasacharide antibodies in supernatants of clones and in the ascitic fluid of mice in ELISA detected by biotinylated tetrasaccharide and synthetic CP adsorbed on the solid phase was higher compared to the use of bacterial CP as well cover antigen. In the reaction of inhibition of the ELISA, the mAb recognized the corresponding carbohydrate epitopes of the bacterial CP of S. pneumoniae serotype 14 dissolved in the liquid phase better than tetrasaccharide ligand and synthetic CP. Conclusion. To detect mAb to tetrasaccharide in ELISA preferably to use synthetic analogues of the CP as solid phase antigens. The obtained mAb to tetrasaccharide can be used to determine the representation of the protective tetrasaccharide epitope of CP in the development of pneumococcal vaccines.


2021 ◽  
pp. 1-25
Author(s):  
Yali Shao ◽  
Ramesh K. Agarwal ◽  
Xudong Wang ◽  
Baosheng Jin

Abstract In recent decades, increasing attention has been focused on accurate modeling of circulating fluidized bed (CFB) risers to provide valuable guidance to design, optimization and operation of reactors. Turbulence model plays an important role in accurate prediction of complex gas-solid flows. Recently developed Wray-Agarwal (WA) model is a one-equation turbulence model with the advantages of high computational efficiency and competitive accuracy with two-equation models. In this paper for the first time, Eulerian-Eulerian approach coupled with different turbulence models including WA model, standard κ-ε model and shear stress transport (SST) κ-ω model is employed to simulate two-phase flows of gas phase and solid phase in two CFB risers, in order to assess accuracy and efficiency of WA model compared to other well-known two-equation models. Predicted gas-solid flow dynamic characteristics including the gas-solid volume fraction distributions in radial and axial directions, pressure profiles and solid mass flux distributions are compared with data obtained from experiment in detail. The results demonstrate WA model is very promising for accurate and efficient simulation of gas-solid multiphase flows.


2019 ◽  
Vol 285 ◽  
pp. 361-366 ◽  
Author(s):  
Khalil Traidi ◽  
Véronique Favier ◽  
Philippe Lestriez ◽  
Karl Debray ◽  
Laurent Langlois ◽  
...  

In this paper, a new elastic viscoplastic micromechanical modelling is proposed to represent the semi-solid behaviour and predict the ductile-brittle transition of the C38LTT near the solidus. It is based on a viscoplastic modelling previously presented in [1]. The originality of the new model comes from three main enhancements: the transition between the solid state and the semi-solid state was included meaning that the material properties were taken temperature-dependent, the elastic properties was taken into account similarly as [2] and the evolution of the internal variable describing the degree of agglomeration of the solid phase was enhanced. The model was implemented in the commercial software FORGE©. Tensile tests representing the experimental thermal conditions and obtained using a GLEEBLE© machine were simulated. The comparison of the predicted and experimental results shows that, for the first time to our knowledge, the three steps of the load-displacement response and ductile-brittle transition were successfully described.


1990 ◽  
Vol 36 (9) ◽  
pp. 1679-1683 ◽  
Author(s):  
E S Lianidou ◽  
T K Christopoulos ◽  
E P Diamandis

Abstract We describe the first time-resolved immunofluorometric assay for creatine kinase (EC 2.7.3.2) isoenzyme MB (CK-MB) in serum. The assay is based on the formation of the complex: solid-phase anti-CK-MB-CK-MB-biotinylated anti-CK-BB-streptavidin-BCPDA-Eu3+, where anti-CK-MB and anti-CK-BB are monoclonal antibodies against the CK isoenzymes MB and BB, respectively, and BCPDA is the europium chelator 4,7-bis(chlorosulfophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid. The solid-phase complex is fluorescent and is measured on the dry solid-phase (microtiter well) in a specially designed time-resolved fluorometer that uses laser excitation. The assay requires 25 microL of serum and is not affected by the presence of either CK-MM (up to 5000 micrograms/L) or CK-BB (up to 1000 micrograms/L) in the sample. Precision and accuracy indices for the assay were satisfactory.


2019 ◽  
Vol 7 (46) ◽  
pp. 26504-26512 ◽  
Author(s):  
Atanu Jana ◽  
Shynggys Zhumagali ◽  
Qiankai Ba ◽  
Arun S. Nissimagoudar ◽  
Kwang S. Kim

We report, for the first time, the solid-phase gram-scale synthesis of two lead-free, zero-dimensional (0D) fluorescent organic–inorganic hybrid compounds, [Bu4N]2[MnBr4] (1) and [Ph4P]2[MnBr4] (2).


2019 ◽  
Vol 43 (34) ◽  
pp. 13554-13570 ◽  
Author(s):  
Hamed Sahebi ◽  
Elaheh Konoz ◽  
Ali Ezabadi

In this study, DABCO-based ionic liquid-functionalized magnetic iron oxide nanoparticles were synthesized for the first time by the quaternization reaction with 1-(2,3-dihydroxypropyl)-1,4-diazabicyclo[2.2.2]octanylium chloride and chloro-functionalized Fe3O4 nanoparticles.


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