Search results for "solution"
showing 10 items of 5638 documents
Water-insoluble β-cyclodextrin–epichlorohydrin polymers for removal of pollutants from aqueous solutions by sorption processes using batch studies: A…
2017
This review is dedicated to Giangiacomo Torri (Istituto di Chimica e Biochimica G. Ronzoni, Milan, Italy) in celebration of his retirement.; International audience; Although water-insoluble cyclodextrin-epichlorohydrin polymers have been known for half a century, these materials are of continued interest to the scientific community, in particular for their interesting environmental applications as sorbents in liquid-solid sorption processes. However, in spite of the abundance of literature and conclusive results obtained at the laboratory scale, interpreting the mechanisms of pollutant elimination remains an interesting source of debate and sometimes of contradiction. This review summarizes…
Chlorinated and methylated dibenzothiophenes: Preparation of the model compounds and their analysis from some environmental samples
1990
Abstract Polychlorinated and polymethylated dibenzothiophenes if occuring in the environment can cause environmental hazards and problems like chlorinated dibenzodioxins and dibenzofurans. Some chlorinated and methylated dibenzothiophenes have been synthesized to serve as model compounds in environmental and toxicological analysis. The synthesis mixtures and some environmental samples have been analyzed by high resolution GC/low resolution MS. This investigation showed that the concentrations of these compounds in environmental samples were below ppb level but it did not exclude the occurence of these compounds in our environment. More investigation is needed.
Novel poly (ionic liquid)-based anion exchange membranes for efficient and rapid acid recovery from industrial waste
2020
Abstract Owing to the less energy consumption, positive impact on the environment, and prospect of providing clean water resources, anion exchange membranes (AEMs) are promising materials for acid recovery from various industrial wastewater/effluent. Based on the diffusion dialysis process, AEMs selectively allow rapid proton permeation while efficiently retaining metal ions. To enhance the efficiency of the acid recovery process, precise control of macromolecular architecture and chemical composition that enables high hydrophilicity, proton conductivity through the membrane, and ion exchange capacity is required. In this direction, we report on the one-step fabrication of novel poly (ionic…
1991
L'etude viscosimetrique, potentiometrique et conductimetrique montre que le copolymere forme un complexe de stœchiometrie 2:1 avec le chlorure de palmityltrimethylammonium. Avec le laurylsuslfate de sodium, il y a d'abord formation d'un complexe de composition 2:1 puis par addition supplementaire du surfactant, formation d'un complexe 1:1
1990
It is shown that the block-like structure of the polyampholyte poly(methacrylic acid)-block-poly(1-methyl-4-vinylpyridinium chloride) considerably influences its conformational behaviour. This specific behaviour is explained by the formation of intra-macromolecular polyelectrolyte complexes stabilized by cooperative ionic contacts between acidic and basic units near the isoelectric point (i. e. p.). The structure of the block-polyampholyte at the i. e. p. is suggested to be close to the structure of non-stoichiometric polyelectrolyte complexes. The complex formation ability of the block-polyampholyte with respect to anionic, cationic, and nonionic polymers is also studied. By means of poten…
Nitroarene hydrogenation catalysts based on Pd nanoparticles glued with PDA on inorganic supports: Multivariate Curve Resolution as an useful tool to…
2021
[EN] Two green catalysts based on Pd(0) nanoparticles (Pd NPs) anchored through PDA on porous silica and magnetite have been synthesized using a generalized simple and reproducible "two-step" methodology. Both catalysts were tested for a model reaction, the hydrogenation of 4-nitrophenol using NaBH4 as the hydrogenating agent, and especially good activity has been achieved in the case of the catalysts containing magnetite as inorganic core (Pd NPs-PDA@Fe3O4). We analyzed the effect associated with the catalyst separation method (centrifugation or magnetically) that affect to the distribution and aggregation degree of the Pd NPs. In addition, we also correlate the final catalyst morphology w…
Molecular stabilization of chemically exfoliated bare MnPS3 layers
2021
Transition metal chalcogenophosphates of general formula MPX3 have attracted recent interest in the field of 2D materials due to the possibility of tuning their properties when reaching the 2D limit. Several works address this challenge by dry mechanical exfoliation. However, only a few of them use a scalable approach. In this work, we apply a general chemical protocol to exfoliate MnPS3. The method uses in a first step chemical intercalation and liquid phase exfoliation, followed in a second step by the addition of molecules used as capping agents on the inorganic layers. Therefore, molecules of different nature prompts the quality of the exfoliated material and its stabilization in aqueou…