Selective Adsorption Processes : N-ISELF

1984 ◽  
pp. 625-656
Author(s):  
Philippe Jacob
Keyword(s):  
Selective Adsorption ◽  
Adsorption Processes

scholarly journals Synthesis of a magnetic C@Co material via the design of a MOF precursor for efficient and selective adsorption of water pollutants

2021 ◽  
Author(s):  
Yu Liu ◽  
Yan Wang ◽  
Xiao-Sa Zhang ◽  
Wen-Ze Li ◽  
Ai-Ai Yang ◽  
...  
Keyword(s):  
Active Sites ◽  
Organic Dyes ◽  
Selective Adsorption ◽  
Catalytic Performance ◽  
Adsorption Processes ◽  
Carbon Coated ◽  
Adsorption Of Water ◽  
Metal Organic ◽  
Cobalt Nanoparticle ◽  
Fast Acting

Abstract 3D metal-organic frameworks (MOFs) can be appropriate templates for the fabrication of nanomaterials due to they have active sites exposed on the channel or surface, which thus provide them with improved catalytic performance. In this study, a 3D cobalt-based MOF [Co(H2bpta)]n (Co-MOF), where H4bpta denotes 2,2′,4,4′-biphenyltetracarboxylic acid, has been constructed with the use of a ligand with a high carbon content. On this basis, a 2D magnetic carbon-coated cobalt nanoparticle composite (C@Co) was prepared by using the title MOF. Magnetic C@Co can readily absorb dye from the solution and can thus act as an inexpensive and fast-acting adsorbent. Moreover, we have explored the adsorption isotherms, kinetics and thermodynamics of the anion dyes in detail. The adsorption capacity of the C@Co for investigated methyl orange (MO) and congo red (CR) dyes were 773.48 and 495.66 mg g− 1, respectively. It is noteworthy that MO adsorption is higher in existing materials. Thermodynamic studies suggest that the adsorption processes are spontaneous and exothermic. This study opens a new insight into the synthesis and application of carbon-based materials that enable the selective removal of organic dyes.

scholarly journals Analysis of Cuticular Lipids of the Pharaoh Ant (Monomorium pharaonis) and Their Selective Adsorption on Insecticidal Zeolite Powders

2018 ◽  
Vol 19 (9) ◽  
pp. 2797 ◽  
Author(s):  
Heleen Van Den Noortgate ◽  
Bert Lagrain ◽  
Tom Wenseleers ◽  
Johan Martens
Keyword(s):  
Chemical Composition ◽  
Insecticidal Activity ◽  
Selective Adsorption ◽  
Epicuticular Wax ◽  
Gas Chromatography Mass Spectrometry ◽  
Adsorption Selectivity ◽  
Adsorption Mechanisms ◽  
Pore Mouth ◽  
Adsorption Processes ◽  
Epicuticular Wax Layer

The pharaoh ant is a notorious and hard to eradicate pest, which poses a threat in hospitals, spreading pathogens and contaminating sterile equipment. When applied on ants, zeolites adsorb part of their epicuticular wax layer. The ants are then vulnerable to desiccation, since this layer regulates water exchange. We analyzed the chemical composition of this wax layer using GC-MS (Gas Chromatography-Mass Spectrometry). A hexane wash of M. pharaonis foragers resulted in the identification of 53 components, four of which were not previously defined in Monomorium species. Selective adsorption of specific compounds on zeolites assisted in the identification of compounds which could not be separated on the GC column and allowed for the identification of three additional compounds. Zeolites show different affinities for the wax compounds depending on pore structure and chemical composition. Selective adsorption of alkanes on zeolites is also investigated in the fields of refinery processes and catalysis. Pore mouth and key lock adsorption mechanisms and selectivity according to molecular weight and branching, investigated in these fields, are also involved in adsorption processes of epicuticular waxes. The insecticidal activity of a zeolite is related to adsorption selectivity rather than capacity. One of the best adsorbing zeolites showed limited insecticidal activity and can be considered as a non-lethal alternative for epicuticular wax sampling.

scholarly journals Evaluation of an Experimentally Designed Molecular Imprinted Polyurethane Foam Performance for Extraction of Alprazolam

2019 ◽  
Vol 57 (7) ◽  
pp. 662-670
Author(s):  
Zeynab Tavakoli ◽  
Majid Soleimani ◽  
Mir Mohammad Alavi Nikje
Keyword(s):  
Polyurethane Foam ◽  
High Efficiency ◽  
Solid Phase ◽  
Selective Adsorption ◽  
Selective Extraction ◽  
Extraction Methods ◽  
Effective Parameters ◽  
Rigid Foam ◽  
Adsorption Processes ◽  
Central Composite

Abstract Industrial polyurethane rigid foam (PUF) was selected as a substrate for selective solid phase extraction of Alprazolam. Effective parameters for raising selectivity of the PUF were evaluated. Synthetic molecularly imprinted polyurethane foam (MIPUF) was tracked as selective adsorbent and its characteristic was pondered by analytical methods. Optimization was done by central composite design (CCD) to have high efficiency of the polymer adsorption. Two different extraction methods were compared in the selective adsorption processes using MIPUF and NIPUF, batch system and continuous (cartridge) system. Results of the adsorption of alprazolam on the MIPUF had 39% more recovery than NIPUF (reference polymer). Then, the proposed method suggests a selective extraction of mentioned analyte from urine and tablets as complex matrixes.

Global versus local adsorption selectivity

2015 ◽  
Vol 14 (4) ◽  
pp. 563-570 ◽  
Author(s):  
Françoise Pauzat ◽  
Gael Marloie ◽  
Alexis Markovits ◽  
Yves Ellinger
Keyword(s):  
Lactic Acid ◽  
Density Functional ◽  
Selective Adsorption ◽  
Enantiomeric Excess ◽  
Local Property ◽  
Adsorption Selectivity ◽  
Adsorption Sites ◽  
Simulation Techniques ◽  
Adsorption Processes ◽  
Property Changes

AbstractThe origin of the enantiomeric excess found in the amino acids present in the organic matter of carbonaceous meteorites is still unclear. Selective adsorption of one of the two enantiomers existing after a racemic formation could be part of the answer. Hereafter we report a comparative study of the adsorption of the R and S enantiomers of α-alanine and lactic acid on the hydroxylated {$10\bar 10$} chiral surface of α-quartz using numerical simulation techniques. Structurally different adsorption sites were found with opposite R versus S selectivity for the same molecule–surface couple, raising the problem of whether to consider adsorption as a local property or as a global response characteristic of the whole surface. To deal with the second term of this alternative, a statistical approach was designed, based on the occurrence of each adsorption site whose energy was calculated using first principle periodic density functional theory. It was found that R-alanine and S-lactic acid are the enantiomers preferentially adsorbed, even if the adsorption process on the quartz {$10\bar 10$} surface stays with a disappointingly poor enantio-selectivity. Nevertheless, it highlighted the important point that considering adsorption as a global property changes perspectives in the search for more efficient enantio-selective supports and more generally changes the way to apprehend adsorption processes in astro-chemistry/biology.

scholarly journals INDIUM EXTRACTION FROM SOLUTIONS WITH MODIFIED ALUMINOSILICATES

2018 ◽  
Vol 59 (7) ◽  
pp. 35
Author(s):  
Konstantin L. Timofeev ◽  
Gennadiy I. Maltsev ◽  
Alexeiy V. Sviridov
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Selective Adsorption ◽  
Exchange Capacity ◽  
Static Exchange Capacity ◽  
Adsorption Processes ◽  
Iron And Zinc ◽  
Initial Content ◽  
Zinc Production ◽  
Modified Aluminosilicates

The aim of this work was to study the adsorption of indium from aqueous solutions on modified highly dispersed aluminosilicates for the recovery of indium from technological solutions. The adsorption isotherms of indium, iron and zinc from multi component solutions on modified by di(2-ethylhexyl) phosphoric acid montmorillonite were obtained. It was shown that adsorption processes can be reliably described by models of Langmuir and Freundlich (R2  =  0.96–0.99). The shape of the isotherms is determined both by the surface properties of the sorbent and forms of presence of metal ions in aqueous solutions. The highest value of Langmuir constant Kads = 422.65 for reagent "Metоsol" was obtained for ions of indium, which indicates the preferential affinity of the sorbing mineral to this element, since the corresponding figures for the ions Fe2+ (1.09) and Zn2+ (0.78) are close to unity. At sorption of metal ions from model solution in the range of acidity of 1-20 g/dm3 of H2SO4 the extraction of indium remains unchanged at ~70 %, and iron – is reduced from 39 to 15% of the initial content. With the further increase of acidity to 100 g/dm3 of H2SO4, the recovery of indium is reduced to 40 %; iron down to 14 %. In the examined range of concentration of sulfuric acid the extraction of zinc is from 6.0 to 7.5 percent. The value of the static exchange capacity for the studied metals are mmol/g: 0.39–0.23 of indium; 0.11–0.04 of iron(III); 0.05–0.04 of zinc. A rank of affinity of reagent "Metоsol" to extract the metal ions from solution with pre-reduced iron(III)  was In3+ > Fe2+ > Zn2+ which determines the feasibility of its use for the selective adsorption of indium from the complex composition of technological solutions of zinc production.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

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