Search results for "liquids"

Miscela binaria liquido ionico/[bmim][N3]: un mezzo efficace per la sintesi di arilazidi mediante SNAr

Acidic imidazolium salts: catalysts for biomass transformation

Gluconic acid for eco-friendly Ionic Liquids: chemical and biological investigations

Ionic liquids (ILs) are employed in several fields thanks to their well-known properties. For a long time, ILs were considered the “green” alternative to conventional organic solvents.1 However, the increasing attention on environmental health led to consider different ILs structures and alternative synthetic pathways. Considering the tunability of IL structures, new synthetic approaches with natural sources as starting materials were taken into account.2 Here, new eco-friendly ILs were synthesised using gluconic acid. The structures carry gluconic moiety on the cation or as the anion (Figure 1). Hence, several OH groups decrease toxicity and shape a high coordinative site. These new organi…

SYNTHESIS OF OXADIAZOLE BASED ORGANIC SALTS

2010

Functionalised Imidazolium Dicationic Ionic Liquids used as reaction media for base catalyzed organic reactions

Do we understand the solid-like elastic properties of confined liquids?

2021

Recently, in polymeric liquids, unexpected solid-like shear elasticity has been discovered, which gave rise to a controversial discussion about its origin (1⇓–3). The observed solid-like shear modulus G depends strongly on the distance L between the plates of the rheometer according to a power law G ∝ L − p with a nonuniversal exponent ranging between p = 2 and p = 3 . Zaccone and Trachenko (4) have published an article in which they claim to explain these findings by a nonaffine contribution to the liquid shear modulus. The latter is represented as Δ G ∝ − ∑ λ = L , T 1 V … [↵][1]1To whom correspondence may be addressed. Email: giancarlo.ruocco{at}roma1.infn.it. [1]: #xref-corresp-1-1

Supported ionic liquids. New recyclable materials for the L-proline-catalyzed aldol reaction

2006

New materials for L-proline recycling have been developed. These materials have been applied to the L-proline-catalyzed aldol reaction between acetone and several aldehydes. The L-proline has been supported on the surface of modified silica gels with a monolayer of covalently attached ionic liquid with or without additional adsorbed ionic liquid. Good yields and ee values, comparable with those obtained under homogeneous conditions, have been obtained especially with imidazolinium-modified and 4-methylpyridinium-modified silica gels. Moreover, these materials have been easily recovered by simple filtration and studies about their reuse have been carried out. These studies showed that these …

Carbon Nanomaterial Doped Ionic Liquid Gels for the Removal of Pharmaceutically Active Compounds from Water.

2019

Due to large drug consumption, pharmaceutically active compounds (PhACs) can be found as water contaminants. The removal of PhACs is a significant issue, as they can easily overtake traditional purification methods. Because of their surface properties, carbon nanomaterials are among the most efficient materials able to adsorb PhACs. However, their limitation is their recovery after use and their possible leakage into the aquatic system. Consequently, new hybrid supramolecular ionic liquid gels (HILGs) have been designed for the adsorption of some antibiotic drugs (ciprofloxacin and nalidixic acid) from water. The chemical&ndash

Use of supercritical CO2 and N2 as dissolved gases for the atomization of ethanol and water

2012

Supercritical dissolved gas atomization (SDGA) is an atomization process in which a gas at temperatures and pressures above the critical point is used as the atomizing medium. The concept of SDGA has been applied mainly using CO 2 as atomizing gas in various processes developed for the production of fine particles of pharmaceuticals, polymers, and chemical products and for the atomization of fuels. In this work, SDGA, using ethanol and water as the liquids to be atomized, has been experimentally studied. The spray characteristics, in terms of droplet size and distribution, have been investigated using a laser diffraction analyzer. Ethanol has been chosen due to the large miscibility with CO…

Extent of the influence of phosphate buffer and ionic liquids on the reduction of the silanol effect in a C18 stationary phase

2017

The presence of anionic free silanols in the silica-based stationary phases gives rise to broad and asymmetrical peaks when cationic basic compounds are chromatographed using hydro-organic mobile phases. The addition to the mobile phase of a reagent with ionic character prevents the access of analytes to the free silanols, improving the peak shape. The silanol activity can be affected by the buffer concentration and mobile phase pH, factors that are not always considered sufficiently in the literature. In this work, the chromatographic behaviour of three basic β-adrenoceptor antagonists (acebutolol, nadolol and timolol), using mobile phases containing acetonitrile, was examined at different…