Search results for "SOLVENT"
showing 10 items of 1395 documents
Pyrene derived functionalized low molecular weight organic gelators and gels
2008
Pyrene derived binary functionalized low molecular weight organic gelators (FLMOGs) and gels thereof in selected organic solvents were synthesized and characterized. The functionality refers to a functional group that does not take part in formation of the supramolecular gel network, but remains free and available for other purposes, such as to bind nanoparticles or other molecules into the gel structure. Functional groups were observed to disturb gel formation strongly, if they interact with each other within the same supramolecule due to the formation of competitive structures. Preventing such interactions restored the original gel properties. A gel with weaker supramolecular bonding than…
Solvent-Dependent Self-Assembly of an Oxalato-Based Three-Dimensional Magnet Exhibiting a Novel Architecture.
2016
The old but evergreen family of bimetallic oxalates still offers innovative and interesting results. When (Me4N)3[Cr(ox)3]·3H2O is reacted with Mn(II) ions in a nonaqueous solvent, a novel three-dimensional magnet of the formula [N(CH3)4]6[Mn3Cr4(ox)12]·6CH3OH is obtained instead of the one-dimensional compound obtained in water. This new material exhibits an unprecedented stoichiometry with a binodal (3,4) net topology and the highest critical temperature (TC = 7 K) observed so far in a manganese-chromium oxalate based magnet.
Liquid–liquid equilibria of 4-methyl-2-pentanone+1-propanol or 2-propanol+water ternary systems: Measurements and correlation at different temperatur…
2014
Abstract In this work, experimental liquid–liquid equilibria data of the systems 4-methyl-2-pentanone + 1-propanol + water and 4-methyl-2-pentanone + 2-propanol + water are presented. The liquid–liquid equilibria of both systems have been measured at 283.2 and 323.2 K. The NRTL and UNIQUAC models were successfully applied to fit the data for both ternary systems. The binodal lines were compared to the values predicted by the UNIFAC-LLE and UNIFAC models. Moreover, the solvent capability of 4-methyl-2-pentanone was checked in order to separate the azeotropic mixtures formed by propanol's and water.
Measurements and correlation of liquid–liquid equilibria of 4-methyl-2-pentanone+ethanol+water and 4-methyl-2-pentanone+n-butanol+water ternary syste…
2012
Abstract In this work, experimental liquid–liquid equilibria data of the systems 4-methyl-2-pentanone + ethanol + water and 4-methyl-2-pentanone + n-butanol + water are presented. The liquid–liquid equilibria of both systems have been measured between 283.2 and 323.2 K. The NRTL and UNIQUAC models were applied to fit the data for both ternary systems. The interaction parameters obtained from both models successfully correlated the equilibrium compositions. The binodal lines were compared to the values predicted by the UNIFAC-LLE and UNIFAC models. Moreover, the solvent capability of 4-methyl-2-pentanone was checked in order to separate these azeotropic mixtures alcohol + water.
Application of a low transition temperature mixture for the dispersive liquid–liquid microextraction of illicit drugs from urine samples
2021
© 2021 by the authors.
Biocatalysis and biorecognition in nonaqueous media. Some perspectives in analytical biochemistry
1995
Biocatalysis and, to a lesser extent, biorecognition in non-aqueous media (including organic solvents as well as supercritical fluids and gases) constitute at present an exciting research area which has already demonstrated its biotechnological potential in numerous, varied applications. Less attention, however, has been paid to its analytical possibilities, even though many advantages have been postulated and a wide range of poorly water-soluble analytes are present in samples (or waste materials) from food and drink, petrochemical, pharmaceutical, military and other industries. The main approaches, developed in recent years to exploit the use of enzymes, antibodies or antibody mimics in w…
A miniaturized method for estimating di(2-ethylhexyl) phthalate in bivalves as bioindicators.
2012
This work has developed a miniaturized method based on matrix solid phase dispersion (MSPD), using C18 as dispersant and acetonitrile-water as eluting solvent, for the analysis of di(2-ethylhexyl) phthalate (DEHP) in biota samples by capillary liquid chromatography coupled to in-tube solid phase microextraction and diode array detection. Recovery studies showed that the combination of C18-Florisil® was optimal using low amount of samples (0.1 g) and with low volumes of acetonitrile-water (2.6 mL 1:3.25, v/v). The sample is processed in less than 30 min, no evaporation step is required. The proposed method was applied to the analysis of DEHP in mussels and of the coastal waters in which they…
DEEP EUTECTIC SOLVENTS: FROM SUSTAINABLE REACTION MEDIA TO SUPRAMOLECULAR MATERIALS
Colloidal stability of halloysite clay nanotubes
2019
Abstract The colloidal stability of halloysite clay nanotubes dispersion is reviewed showing the strategy and the mechanism to obtain stable systems in water and apolar solvents. The selective modification of halloysite inner/outer surfaces can be achieved by exploiting electrostatic interactions. The adsorption of anionic surfactants onto the halloysite cavity allows generating inorganic cylindrical micelles that can be separated from the solvent. On the other hand, the functionalization of halloysite shell by positively charged surfactants drives to obtain stable water-in-oil emulsions. The interactions with ionic and nonionic polymers alters the dispersability of halloysite due to electr…
New macrocycles derived from biphenyl for pH-switched solvent extraction
2006
Abstract Four new fluorescent macrocyclic ligands derived from biphenyl are described. The new compounds have been used in liquid–liquid extraction experiments and the influence of pH has been studied in those ligands containing carboxylic groups. The results obtained for the latter ligands have been compared with those observed in the presence of an external acid.