scholarly journals Highly selective adsorption of ethylene over ethane in a MOF featuring the combination of open metal site and π-complexation

2015 ◽  
Vol 51 (13) ◽  
pp. 2714-2717 ◽  
Author(s):  
Yiming Zhang ◽  
Baiyan Li ◽  
Rajamani Krishna ◽  
Zili Wu ◽  
Dingxuan Ma ◽  
...  
Keyword(s):  
Selective Adsorption ◽  
Adsorption Selectivity ◽  
Metal Site ◽  
Π Complexation

A MOF featuring the combination of open metal site and π-complexation demonstrates exceptional ethylene–ethane adsorption selectivity at 318 K.

Core-Shell Molecularly Imprinted Polymer Nanocomposites for Biomedical and Environmental Applications

2019 ◽  
Vol 25 (34) ◽  
pp. 3633-3644
Author(s):  
Nasrullah Shah ◽  
Saba Gul ◽  
Mazhar Ul-Islam
Keyword(s):  
Food Processing ◽  
Selective Adsorption ◽  
Environmental Applications ◽  
Core Shell ◽  
Template Molecule ◽  
Hollow Core ◽  
Imprinted Polymer ◽  
Adsorption Selectivity ◽  
Molecularly Imprinting Polymers ◽  
Relative Adsorption

: Core-shell polymers represent a class of composite particles comprising of minimum two dissimilar constituents, one at the center known as a core which is occupied by the other called shell. Core-shell molecularly imprinting polymers (CSMIPs) are composites prepared via printing a template molecule (analyte) in the coreshell assembly followed by their elimination to provide the everlasting cavities specific to the template molecules. Various other types of CSMIPs with a partial shell, hollow-core and empty-shell are also prepared. Numerous methods have been reported for synthesizing the CSMIPs. CSMIPs composites could develop the ability to identify template molecules, increase the relative adsorption selectivity and offer higher adsorption capacity. Keen features are measured that permits these polymers to be utilized in numerous applications. It has been developed as a modern technique with the probability for an extensive range of uses in selective adsorption, biomedical fields, food processing, environmental applications, in utilizing the plant's extracts for further applications, and sensors. This review covers the approaches of developing the CSMIPs synthetic schemes, and their application with special emphasis on uses in the biomedical field, food care subjects, plant extracts analysis and in environmental studies.

scholarly journals Husk of Agarwood Fruit-Based Hydrogel Beads for Adsorption of Cationic and Anionic Dyes in Aqueous Solutions

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong
Keyword(s):  
Aqueous Solutions ◽  
Selective Adsorption ◽  
Order Model ◽  
Anionic Dyes ◽  
Adsorption Selectivity ◽  
Hydrogel Beads ◽  
Batch System ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.

Directly decorated CeY zeolite for O2-selective adsorption in O2/N2 separation at ambient temperature

2021 ◽  
Author(s):  
Hanbang Liu ◽  
Danhua Yuan ◽  
Liping Yang ◽  
Jiacheng Xing ◽  
Shu Zeng ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Selective Adsorption ◽  
Air Separation ◽  
Adsorption Selectivity ◽  
First Time

The traditional zeolites used in air separation are generally N2-selective adsorbents. It was found for the first time that the O2/N2 adsorption selectivity can be reversed by directly decorating the...

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.

Impact of intrinsic framework flexibility for selective adsorption of sarin in non-aqueous solvents using metal–organic frameworks

2020 ◽  
Vol 22 (11) ◽  
pp. 6441-6448 ◽  
Author(s):  
Jongwoo Park ◽  
Mayank Agrawal ◽  
Dorina F. Sava Gallis ◽  
Jacob A. Harvey ◽  
Jeffery A. Greathouse ◽  
...  
Keyword(s):  
Selective Adsorption ◽  
Metal Organic Frameworks ◽  
Adsorption Selectivity ◽  
Complex Molecules ◽  
Metal Organic

We assess the nontrivial deviation in predicting the adsorption selectivity from bulk mixtures of complex molecules using nanoporous adsorbents approximated as rigid and intrinsically flexible.

Preparation of Triethylenetetramine-Functionalized Adsorbents for Selective Adsorption of Copper and Zinc Ions

2012 ◽  
Vol 557-559 ◽  
pp. 1078-1084
Author(s):  
Chang Kun Liu ◽  
Xu Xin Zhao ◽  
Lin Fang ◽  
Xiao Fang Yue
Keyword(s):  
Metal Ion ◽  
Selective Adsorption ◽  
Ph Effect ◽  
Single Species ◽  
Industrial Applications ◽  
Zinc Ions ◽  
Adsorption Selectivity ◽  
Copper And Zinc ◽  
Zn Ions ◽  
Cu And Zn

Selective adsorption of a target adsorbate is critical in adsorbent performance evaluation, and is of great importance in industrial applications. In this study, the selective adsorption of copper and zinc ions was investigated with the polyamine-functionalized polymeric adsorbents. The adsorbent was prepared by amination of crosslinked poly (glycidyl methacrylate) (PGMA) with triethylenetetramine (TETA). The influencing factors including reaction time and TETA content during adsorbent synthesis were investigated. The prepared adsorbents (P-TETA) was used to study the adsorption selectivity toward copper and zinc ions in single species system (when only one metal ion is present) and binary species system (when both metal ions are present). Both the pH effect and the adsorption isotherm were examined in single and binary species system. It was found that both Cu and Zn ions would be adsorbed onto P-TETA in significant amount in single species system at higher pH values. However, in binary species system with high initial concentrations for both Cu and Zn ions, Cu ions would be selectively adsorbed onto P-TETA, with insignificant amount of Zn ion adsorbed. The higher coordination constant (in Log K form) of Cu-TETA coordination than Zn-TETA coordination was identified as the major mechanism for the selective adsorption of Cu over Zn ions with P-TETA adsorbents.

Adsorption Selectivity of Fatty Acid Collector by Synthetic Magnetite

2014 ◽  
Vol 552 ◽  
pp. 263-268
Author(s):  
Han Quan Zhang ◽  
Feng Ling Wang
Keyword(s):  
Fatty Acid ◽  
Sodium Oleate ◽  
Selective Adsorption ◽  
Indirect Measurement ◽  
Adsorption Rate ◽  
Separation Performance ◽  
Mineral Surface ◽  
Adsorption Selectivity ◽  
Synthetic Magnetite ◽  
Concentrate Grade

Selective adsorption of collectors on mineral surface can directly impact the flotation separation performance. Mineral flotation tests indicated that reverse flotation of synthetic magnetite can only bring a 2 to 4 percent increase in the concentrate grade, tailings grade remains high. The amounts of commonly used fatty acid collector, such as sodium oleate, adsorbed onto mineral surface are measured with indirect measurement to investigate adsorption selectivity of fatty acid collectors by synthetic magnetite. Results showed a higher selectivity in collector adsorption for natural magnetite, with 38.25% difference in the average adsorption rate of sodium oleate between the valuable minerals and gangue, but a less selective adsorption of fatty acid collector onto artificial magnetite, with only 1% difference in the average adsorption rate between its valuable and gangue.

Selective adsorption and separation of stevioside and rebaudioside A by a metal-organic framework with boronic acid

2020 ◽  
Vol 98 (11) ◽  
pp. 708-716
Author(s):  
Guanyu Wang ◽  
Qiaoge Fu ◽  
Ruili Guo ◽  
Zhong Wei
Keyword(s):  
Boronic Acid ◽  
Selective Adsorption ◽  
Metal Organic Framework ◽  
Steviol Glycosides ◽  
Sugar Solution ◽  
Order Kinetic ◽  
Rebaudioside A ◽  
High Concentration ◽  
Adsorption Selectivity ◽  
Metal Organic

The boronic acid functionalization metal-organic frameworks (MOFs), as unique boronate affinity adsorbents, have desired specific molecular affinity for the separation and enrichment of cis-diol-compounds. Herein, the boronic acid functionalized Zn-based MOF adsorbent (MOF-BA) was synthesized through a simple one-step microwave method and used for the recognition and isolation of steviol glycosides (SGs). This MOF-BA exhibits the same spherical structure and isostructure with the parent framework composed only of the primitive ligand as verified by SEM and XRD characterization. It was confirmed that changing the ratio of ligands could achieve the adjustability of the boron content in the framework. At the same time, the MOF-BA-1.0 showed a suitable pore size (4.69 nm), and the presence of boric acid functional groups showed favorable selectivity for stevioside (STV). The static adsorption results showed that adsorption performances of rebaudioside A (RA) and STV from crude sugar solution (5.0 mg mL−1, pH 8) on MOF-BA-1.0 were investigated at 303 K for 15 h. The adsorption capacities for STV and RA were 42.93 mg g−1 and 22.96 mg g−1, respectively, and the adsorption selectivity (αSTV/RA) reached 4.35. The adsorption isotherm and kinetic data of MOF-BA-1.0 for RA and STV obeyed the Langmuir isotherm model and pseudo second order kinetic model, respectively. The study demonstrated that MOF-BA-1.0 adsorbent could be used as a potential adsorbent to purify the active ingredients of stevia and obtain a high concentration of RA products.

scholarly journals Ion-Imprinted Polypropylene Fibers Fabricated by the Plasma-Mediated Grafting Strategy for Efficient and Selective Adsorption of Cr(VI)

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1508 ◽  
Author(s):  
Zhengwei Luo ◽  
Jiahuan Xu ◽  
Dongmei Zhu ◽  
Dan Wang ◽  
Jianjian Xu ◽  
...  
Keyword(s):  
Time Pressure ◽  
Discharge Plasma ◽  
Selective Adsorption ◽  
Polypropylene Fibers ◽  
Adsorption Selectivity ◽  
Plasma Irradiation ◽  
Ion Imprinted ◽  
The Stability ◽  
Kinetics Of

To improve the adsorption selectivity towards hexavalent chromium anion (Cr(VI)), surface Cr(VI)-imprinted polypropylene (PP) fibers were fabricated by the plasma-mediated grafting strategy. Hence, a non-thermal Rradio frequency discharge plasma irradiation followed by a gaseous phase grafting was used to load acrylic acid (AA) onto PP fibers, which was afterwards amidated with triethylenetetramine and subjected to imprinting with a Cr(VI) template. The plasma irradiation conditions, i.e., gas species, output power, pressure, and time, were optimized and then the influence of grafting time, pressure, and temperature on the grafting degree of AA was investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy were used for the characterization of pristine and modified fibers and to confirm the synthesis success. The hydrophilicity of modified fibers was greatly improved compared with pristine PP fibers. The adsorption thermodynamics and kinetics of Cr(VI) were investigated, as well as the elution efficiency and reusability. The prepared imprinted fibers showed superior adsorption selectivity to Cr(VI) compared with non-imprinted fibers. Finally, the stability of the imprinted fibers against the oxidation ability of Cr(VI) is discussed.

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