Selective Adsorption of Water-soluble Ionic Compounds by an Interval Immobilization Technique Based on Molecular Imprinting

The influence of small amounts of dissolved foreign substances on the growth of crystals from saturated solutions has been the subject of much investigation. Usually the added substances have been electrolytes. Dyestuffs have not been neglected, but with some few exceptions comparatively little attention has been given to the effect of non-ionized water-soluble electrolytes such as gelatine or dextrine. As a rule, the presence of the foreign substances is found to cause the crystals to assume a different habit. Whenever this occurs the absorption must have occurred on certain crystal-faces in preference to others, but, although the added material is active by virtue of its close attachment to such faces, it is rarely found to be incorporated into the solid to any great extent. The growing crystals appear to reject the impurity—thrusting it outwards as the growth advances. The action of water-soluble colloids on the halides and certain other salts of lead is exceptional in several ways. Although when such colloids are present in small concentrations one can generally observe a modification of habit, at higher concentrations there may be little selective adsorption, and the result may be a rounded crystal on which no plane faces at all can be distinguished, as if the forces by which atoms are attracted to the structure had been equalized in every direction.

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Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions

Polymers ◽

10.3390/polym13020208 ◽

2021 ◽

Vol 13 (2) ◽

pp. 208

Author(s):

Ramona B. J. Ihlenburg ◽

Anne-Catherine Lehnen ◽

Joachim Koetz ◽

Andreas Taubert

Keyword(s):

Aqueous Solution ◽

Methylene Blue ◽

Methyl Orange ◽

Dye Removal ◽

Selective Adsorption ◽

Water Soluble ◽

Organic Substances ◽

Preferential Adsorption ◽

Dimethyl Ammonium ◽

Dye Solutions

New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.

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Optimization of Mordenite Membranes Using Sucrose Precursor for Pervaporation of Water-Ethanol Mixtures

Membranes ◽

10.3390/membranes11030160 ◽

2021 ◽

Vol 11 (3) ◽

pp. 160

Author(s):

Abdulaziz A. Alomair ◽

Yousef Alqaheem

Keyword(s):

Pyrolysis Temperature ◽

Operating Temperature ◽

Selective Adsorption ◽

Sucrose Concentration ◽

Low Cost ◽

Water Flux ◽

Separation Performance ◽

Carbon Membranes ◽

Adsorption Of Water ◽

High Separation

Post-treated mordenite membranes were prepared using sucrose (C12H22O11) as a carbon precursor to block any pinholes and defects in the zeolite layer. The pervaporation (PV) process was used to separate ethanol from the water. The effects of the sucrose concentration and the pyrolysis temperature (650–850 °C) were investigated, and the resulting high separation performance compared to those post/pre-treated membranes was reported in the literature. In this study, mordenite carbon membranes yielded a water/ethanol separation factor of 990.37 at a water flux of 9.10 g/m2h. The influence of the operating temperature on the performance of the membrane also was considered. It was concluded that the selective adsorption of water through zeolite pores was achieved. The entire preparation procedure was achieved using a rapid, low-cost preparation process.

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Molecularly imprinted nanozymes with faster catalytic activity and better specificity

Nanoscale ◽

10.1039/c8nr09816f ◽

2019 ◽

Vol 11 (11) ◽

pp. 4854-4863 ◽

Cited By ~ 21

Author(s):

Zijie Zhang ◽

Yuqing Li ◽

Xiaohan Zhang ◽

Juewen Liu

Keyword(s):

Activation Energy ◽

Catalytic Activity ◽

Molecular Imprinting ◽

Selective Adsorption ◽

Molecularly Imprinted ◽

Product Release

Molecular imprinting accelerates nanozyme catalysis and improves specificity attributable to selective adsorption of imprinted substrate, decreasing activation energy and facilitating product release.

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Visualizing monolayers with a water-soluble fluorophore to quantify adsorption, desorption, and the double layer

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1419033112 ◽

2015 ◽

Vol 112 (8) ◽

pp. E826-E835 ◽

Cited By ~ 13

Author(s):

Ian C. Shieh ◽

Joseph A. Zasadzinski

Keyword(s):

Double Layer ◽

Fluorescent Dyes ◽

Selective Adsorption ◽

Dye Adsorption ◽

Immiscible Liquid ◽

Water Soluble ◽

Fluorescence Signal ◽

Anionic Phospholipid ◽

Gas Phases ◽

Disordered Phase

Contrast in confocal microscopy of phase-separated monolayers at the air–water interface can be generated by the selective adsorption of water-soluble fluorescent dyes to disordered monolayer phases. Optical sectioning minimizes the fluorescence signal from the subphase, whereas convolution of the measured point spread function with a simple box model of the interface provides quantitative assessment of the excess dye concentration associated with the monolayer. Coexisting liquid-expanded, liquid-condensed, and gas phases could be visualized due to differential dye adsorption in the liquid-expanded and gas phases. Dye preferentially adsorbed to the liquid-disordered phase during immiscible liquid–liquid phase coexistence, and the contrast persisted through the critical point as shown by characteristic circle-to-stripe shape transitions. The measured dye concentration in the disordered phase depended on the phase composition and surface pressure, and the dye was expelled from the film at the end of coexistence. The excess concentration of a cationic dye within the double layer adjacent to an anionic phospholipid monolayer was quantified as a function of subphase ionic strength, and the changes in measured excess agreed with those predicted by the mean-field Gouy–Chapman equations. This provided a rapid and noninvasive optical method of measuring the fractional dissociation of lipid headgroups and the monolayer surface potential.

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Adsorption of water‐soluble polychlorinated biphenyl aroclor 1242 and used capacitor fluid by soil materials and coal chars

Journal of Environmental Science and Health Part A Environmental Science and Engineering ◽

10.1080/10934527909374889 ◽

1979 ◽

Vol 14 (5) ◽

pp. 415-442 ◽

Cited By ~ 5

Author(s):

M. C. Lee ◽

R. A. Griffin ◽

M. L. Miller ◽

E.S.K. Chian

Keyword(s):

Polychlorinated Biphenyl ◽

Water Soluble ◽

Adsorption Of Water ◽

Aroclor 1242

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

10.21203/rs.3.rs-888378/v1 ◽

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.

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