Search results for "CONDENSED MATTER"
showing 10 items of 13918 documents
Reactive Compatibilization of PBT/EVA Blends with an Ethylene-Acrylic Acid Copolymer and a Low Molar Mass Bis-Oxazoline
2004
Polyesters and polyolefins form highly incompatible blends with poor properties and gross morphology that hinder any practical applications. In this work, the possibility to compatibilize an incompatible blend of poly(butylene terephthalate) (PBT) with ethylene vinyl acetate (EVA) by adding a bis-oxazoline compound, 2,2'-(1,3-phenylene)-bis(2-oxazoline) (PBO), and an ethylene acrylic acid copolymer (EAA) as compatibilizer precursors has been studied. The results indicate that the binary uncompatibilized blends show poor mechanical properties and a bad morphology with scarce adhesion between the phases. The situation is only slightly improved when the EAA is added while the best performance …
Self-assembly of square planar rhodium carbonyl complexes with 4,4-disubstituted-2,2′-bipyridine ligands
2020
The impact of non-covalent interactions and reaction conditions on formation and self-assembly of ionic pairs of Rh complexes with 4,4’-disubstituted bipyridine ligands ([Rh(L1)(CO)2][Rh(CO)2Cl2])n (1), [Rh(L1)2Cl2][Rh(CO)2Cl2] (2), ([Rh(L1)(CO)2][Rh(CO)2Cl2][Rh(L1)(CO)2]n([Rh(CO)2(Cl)2])n) (3), ([Rh(L2)CO2] [Rh(CO)2Cl2])n∙EtOH (4), ([Rh(L2)(CO)2])n ([Rh(CO)2Cl2])n (5) (L1 = 4,4’-dimethyl-2,2’-bipyridine, L2 = 4,4’-diamine-2,2’-bipyridine) have been studied. Packing of square planar Rh complexes favor formation of one-dimensional chains. In structure 1, the polymeric chain is formed by the alternating cationic [Rh(L1)(CO)2]+ and the anionic [Rh(CO)2Cl2]- units leading to a neutral pseudo li…
A methodology for the control of the residual lifetimes of carbon fibre reinforced composite pressure vessels
2005
International audience; Pressure vessels must be periodically proof tested. Traditional techniques for metal vessels are inapplicable for composite vessels as the latter do not break by crack propagation so that the reasoning behind the traditional testing procedures is not appropriate. Damage accumulation leading to the degradation of a composite vessel is by fibre failure. Fibres show a wide distribution in strengths and loading a composite inevitably breaks some. The method which has been developed is supported by an analysis of delayed fibre failure due to the relaxation of the resin around fibre breaks. This provokes overloading of intact fibres neighbouring breaks. The time until a cr…
Charged supramolecular assemblies of surfactant molecules in gas phase
2016
The aim of this review is to critically analyze recent literature on charged supramolecular assemblies formed by surfactant molecules in gas phase. Apart our specific interest on this research area, the stimuli to undertake the task arise from the widespread theoretical and applicative benefits emerging from a comprehensive view of this topic. In fact, the study of the formation, stability, and physicochemical peculiarities of non-covalent assemblies of surfactant molecules in gas phase allows to unveil interesting aspects such as the role of attractive, repulsive, and steric intermolecular interactions as driving force of supramolecular organization in absence of interactions with surround…
Physicochemical investigation of surfactant-coated gold nanoparticles synthesized in the confined space of dry reversed micelles
2006
Abstract Gold nanoparticle/surfactant composites have been synthesized by a novel reduction reaction in the confined space of dry sodium bis(2- ethylhexyl)sulfosuccinate (AOT) or lecithin reversed micelles dispersed in n-heptane and cyclohexane, respectively. The reaction was carried out by adding an opportune amount of anhydrous hydrazine/tetrahydrofuran solution to a suspension of HAuCl4-containing dry reversed micelles dispersed in organic solvent. UV–vis investigation ascertained the formation of stable metal gold nanoparticles and the analysis of FT-IR spectra highlighted the formation of an oriented surfactant monolayer at the nanoparticle surface. Simple evaporation under vacuum of t…
Structures and EPR spectra of binary sulfur−nitrogen radicals from DFT calculations
2007
he scattered electron paramagnetic resonance (EPR) spectroscopic data for binary sulfur–nitrogen (S,N) radicals have been compiled and critically assessed.Many of these are inorganic rings or cages.For each species, possible equilibrium structures in the gas phase and the EPR hyperfine coupling (hfc) constants have been calculated with DFT using the B3LYP functional and basis sets of triple-ζ (or better) quality.Good agreement is obtained between calculated and measured values for the well characterized [S3N2]+radical dot, a planar π-radical for which the s-component of the orbitals is likely to be reasonably independent of minor geometrical changes between gas-phase and condensed-phase sta…
Room temperature synthesis of lanthanum phosphates with controlled nanotexture as host for Ln(III) through the Epoxide Route
2022
AbstractHerein, the Epoxide Route, a one-pot room temperature alkalinization method based on the reaction between a nucleophile and an epoxide, has been employed to synthesize LaPO4 in the form of a Rhabdophane phase. The intrinsic features of this synthetic approach allow the reaction to be followed by pH monitoring, making possible the identification of the different precipitation steps involved in the formation of the solid. Once demonstrated the effectiveness of this chemical methodology, the size and shape of the LaPO4 particles were controlled by varying the identity and proportion of the organic co-solvents employed to perform the reaction. By these means, crystalline particles with …
Packing incentives and a reliable N–H⋯N–pyridine synthon in co-crystallization of bipyridines with two agrochemical actives
2011
The co-crystallization of agrochemical actives thiophanate-methyl and thiophanate-ethyl with 2,2′-bipyridine, 4,4′-bipyridine and 1,2-bis(4-pyridyl)ethane was investigated with conventional crystallization, the slurry method and liquid-assisted grinding. Co-crystals of both thiophanates with all bipyridines were found and the structures solved with single crystal X-ray diffraction. Whereas the 2,2′-bipyridine co-crystals seem to form because of a combination of weak interactions, and in the case of the thiophanate-methyl, partly because of close packing incentives, the 4,4′-bipyridine and 1,2-bis(4-pyridyl)ethane co-crystals form mainly because of a favourable N–H···N–pyridine hydrogen bond…
N,N-Dimethyl-N-propylpropan-1-aminium chloride monohydrate
2008
The title compound, C8H20N+·Cl−·H2O, has been prepared by a simple one-pot synthesis route followed by anion exchange using resin. In the crystal structure, the cations are packed in such a way that channels exist parallel to the b axis. These channels are filled by the anions and water molecules, which interact via O—H...Cl hydrogen bonds [O...Cl = 3.285 (3) and 3.239 (3) Å] to form helical chains. The cations are involved in weak intermolecular C—H...Cl and C—H...O hydrogen bonds. The title compound is not isomorphous with the bromo or iodo analogues.
3,4,5-Trimethoxy-4'-methylbiphenyl
2013
In the title compound, C16H18O3, the dihedral angle between the benzene rings is 33.4 (2)°. In the crystal, molecules are packed in a zigzag arrangement along the b-axis and are interconnected via weak C—H⋯O hydrogen bonds, and C—H⋯π interactions involving the methoxy groups and the benzene rings of neighbouring molecules.