Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-flame ionization detection (GC-FID) was applied for the determination of two tricyclic antidepressant drugs (TCAs), amitriptyline and nortriptyline, from water samples. This method is a very simple and rapid method for the extraction and preconcentration of these drugs from environmental sample solutions. In this m...

Dielectric analysis (DEA) shows changes in the properties of a materials as a response to the application on it of a time dependent electric field. Dielectric measurements are extremely sensitive to small changes in materials properties, that molecular relaxation, dipole changes , local motions that involve the reorientation of dipoles, and so can be observed by DEA. Electrical double layer (ED...

Classical manufacturing techniques of advanced polymeric fibers rely on a combination of high polymer crystallinity and high degree of macromolecular alignment to achieve superior mechanical properties. As a consequence, advanced polymeric fibers such as Kevlar and Spectra possess extraordinary strength, but low strains to failure and toughness (energy absorption during rupture). Recent analysi...

A comprehensive model has been developed for calculating the thermal conductivity of aqueous, nonaqueous, and mixed-solvent electrolyte systems ranging from dilute solutions to fused salts or pure solutes. The model consists of a correlation for calculating the thermal conductivity of solvent mixtures and a method for predicting the effect of electrolyte components. The thermal conductivity of ...

Evaluating solvation entropies directly and combining with direct energy calculations is one way of calculating free energies of solvation and is used by Inhomogeneous Fluid Solvation Theory (IFST). The configurational entropy of a fluid is a function of the interatomic correlations and can thus be expressed in terms of correlation functions. The entropies in this work are directly calculated f...

Isopropylammonium formate (IPAF), a new alkylammonium formate (AAF) room temperature ionic liquid, has been synthesized from isopropylamine and formic acid and characterized as an organic solvent mobile phase replacement for reversed-phase liquid chromatography (LC). Characterization of IPAF solvent properties in water such as pH, conductivity, and viscosity, as well as its synthesis, is descri...

ber af problems fer nnr instantaneously While solvent-assisted emulsion systems have met with a degree of success in formulating pressure sensitive adhesives, they have several disadvantages. The solvent content of these systems precludes totally solvent-free adhesives. Also. there is reported evidence that surfactants used to stabilize the emulsion can adversely affect tack properties of the f...

Colloidal suspensions usually consist of colloidal particles of size 1 nm to 1 μm which are surrounded by a solvent, typically water. In these systems the kinetic energy of the colloids at room temperature is about the strength of their interaction energy. Hence, these systems or materials are considered as soft and deformable and known as “soft matter”. Molecular dynamics (MD) simulation of su...

A series of bis(urea) compounds with complementary functional groups similar to the pharmaceutical drug metronidazole and a structural isomer isometronidazole have been synthesized. The gelation properties these were studied in various solvent/solvent mixtures. mechanical strength isomeric gelators was compared using rheology, morphologies xerogels analyzed by scanning electron microscopy. Thes...

The fluorescence quenching of organic dyes via H-bonding interactions is a well-known phenomenon. However, the mechanism of this Hydrogen-Bond Induced Nonradiative Deactivation (HBIND) is not understood. Insight into this process is obtained by probing in the infrared the O–H stretching vibration of the solvent after electronic excitation of a dye with H-bond accepting cyano groups. The fluores...