Preparation of Long-Alkane Monola Yers Adsorbed On Exfoliated Graphite For Neutron Diffraction Studies

1994 ◽  
Vol 376 ◽  
Author(s):  
K. W. Herwig ◽  
B. Matthies ◽  
H. Taub
Keyword(s):  
Neutron Diffraction ◽  
Adsorption Process ◽  
Selective Adsorption ◽  
Exfoliated Graphite ◽  
Polymer Science ◽  
Fluid Mixture ◽  
Solid Interface ◽  
Classic Problem ◽  
Preferential Adsorption ◽  
Adsorption From Solution

ABSTRACTA classic problem in polymer science is the preferential adsorption at a solid interface of one polymer species from a multi-component fluid mixture. Prototype systems for studying this selective adsorption process are solutions consisting of alkane molecules of two different lengths in the presence of a solid interface. Before neutron diffraction could be used to probe structural questions related to the selective adsorption process in such systems, a significant effort was required to develop methods for fabricating suitable samples. We describe techniques for preparing samples of long-alkane monolayers adsorbed on exfoliated graphite by adsorption from solution and by deposition from the vapor phase.

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.

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

Polymers ◽  
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.

Luteolin Imprinted Polymer with Selective Recognition and Adsorption Performance

2014 ◽  
Vol 809-810 ◽  
pp. 297-301
Author(s):  
Ping Rui Meng ◽  
Liang Bo Li
Keyword(s):  
Adsorption Process ◽  
Selective Adsorption ◽  
Methanol Solution ◽  
Selective Recognition ◽  
Imprinted Polymer ◽  
Molecular Imprinted Polymers ◽  
Adsorption Dynamics ◽  
Adsorption Performance ◽  
Recognition Specificity ◽  
Adsorption Amount

In order to selectively separate luteolin from its crude solution, we synthesized luteolin molecular imprinted polymers (LMIP) with high recognition specificity for luteolin, using an imprinting technique. Luteolin was used as template, methanol as solvent, and N,N’-methylenebisacrylamide (MBAA) as the cross-linking. Then prepared LMIP were characterized and evaluated by scanning electron microscope (SEM) and equilibrium absorption experiments. The results showed that the cavities matching with the template molecules in size and structure were present in the LMIP. Adsorption dynamics analysis suggested that, when the adsorption time reached 4 h, the adsorption process had reached balance and the adsorption capacity was at steady state. The selective adsorption amount reached at 35.65 umol/g for the LMIP, while a lower value of 11.68 umol/g for the blank polymer (i.e. nontemplated). Relative to the corresponding blank polymer, LMIP had an excellent recognition to luteolin in methanol solution. Keywords: Molecular imprinting, Molecular recognition, Adsorbent, Luteolin

scholarly journals Efficient and Selective Adsorption of Gold Ions from Wastewater with Polyaniline Modified by Trimethyl Phosphate: Adsorption Mechanism and Application

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 652 ◽  
Author(s):  
Wang ◽  
Zhao ◽  
Wang ◽  
Zhang ◽  
Zhang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Selective Adsorption ◽  
Interaction Mechanism ◽  
Single Layer ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Trimethyl Phosphate ◽  
Selective Recovery

The selective recovery of gold from wastewater is necessary because it is widely used in various fields. In this study, a new polymeric adsorbent (TP-AFC) was prepared by modifying polyaniline with trimethyl phosphate for the selective recovery of gold from wastewater. Bath experiments were carried out to explore the adsorption capacity and mechanism. The optimum pH of adsorption is 4. The adsorption equilibrium is reached at 840 min. The maximum adsorption capacity is 881 mg/g and the adsorption was a spontaneous endothermic process. The adsorption process fitted well with pseudo second-order kinetic and the Langmuir-models. The single-layer chemisorption governed the adsorption process. In addition, the application in wastewater indicated that the interfering ions had no effect on the adsorption of gold ions. TP-AFC has good selectivity. The interaction mechanism was mainly ion exchange and complexation. In general, TP-AFC was successfully prepared and has an excellent future in practical application.

The structure of a fluid mixture of deuterated ethane and deuterated methane by high-pressure neutron diffraction experiments

2001 ◽  
Vol 115 (12) ◽  
pp. 5561-5566 ◽  
Author(s):  
Till Pfleiderer ◽  
Helmut Bertagnolli ◽  
Klaus Tödheide ◽  
Henry E. Fischer
Keyword(s):  
High Pressure ◽  
Neutron Diffraction ◽  
Fluid Mixture

scholarly journals Selective removal of silicic acid by a gallic-acid modified resin

2019 ◽  
Vol 9 (4) ◽  
pp. 431-441
Author(s):  
Shuqin Bai ◽  
Jue Han ◽  
Cong Du ◽  
Wei Ding
Keyword(s):  
Adsorption Capacity ◽  
Gallic Acid ◽  
Silicic Acid ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Selective Adsorption ◽  
Hydroxyl Groups ◽  
Acid Type ◽  
The Common ◽  
Common Anion

Abstract To remove silicic acid from aqueous solutions, a novel gallic acid-type resin (GA-type resin) was prepared by a grafting method. The effects of the adsorption capacity, pH and presence of NaCl, NaNO3, Na2SO4, and NaCO3 salts on the silicic acid removal were studied. The GA-type resin adsorbs monosilicic acid, silicate ions, and polymeric silicic acid. The adsorption capacity of 4.64–4.94 mg/g was achieved in a short adsorption time (Qm of 8.99 mg/g) and is 30–40 times larger than that of the OH-type resin. The silicic acid removal efficiency was almost unaffected by the pH and common anions when the common anion and silicic acid contents were similar, proving the GA-type resin exhibits an excellent performance for selective adsorption of silicic acid. The Temkin isotherm model can well describe the adsorption process, which is chemical adsorption, and indicates that the adsorption heat decreases with the increasing adsorption amount. The adsorption mechanism of silicic acid on the GA-type resin involves dehydration condensation reactions of the hydroxyl groups in silicic acid and gallic acid. The GA-type resin can be efficiently regenerated and reused after treatment with an HCl solution.

Premelting of ice in exfoliated graphite; a neutron diffraction study

1992 ◽  
Vol 125 (1-2) ◽  
pp. 33-41 ◽  
Author(s):  
J.-M. Gay ◽  
J. Suzanne ◽  
J.G. Dash ◽  
Haiying Fu
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Exfoliated Graphite

scholarly journals Super and Selective Adsorption of Cationic Dyes onto Carboxylate-Modified Passion Fruit Peel Biosorbent

2021 ◽  
Vol 9 ◽  
Author(s):  
Kaiwei Chen ◽  
Linlin Du ◽  
Peng Gao ◽  
Junli Zheng ◽  
Yuanli Liu ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Selective Adsorption ◽  
Low Cost ◽  
Methyl Violet ◽  
Passion Fruit ◽  
Cationic Dyes ◽  
Polluted Water ◽  
Isotherm Models ◽  
Fruit Peel ◽  
Environmental Friendliness

The carboxylate-functionalized passion fruit peel (PFPCS) was an efficient and rapid biosorbent for wastewater treatment. The PFPCS exhibited excellent selectivity to the cationic dyes, where the maximum adsorption capacities for methylene blue (MB) and methyl violet (MV) were 1,775.76 mg g−1 and 3,756.33 mg g−1, respectively. And the adsorption process of MB and MV on PFPCS reached equilibrium within 20 min. Moreover, the adsorption conditions and mechanisms were investigated. The adsorption process was in good agreement with the pseudo-second-order and Langmuir isotherm models. The adsorption mechanism was also proposed to be electrostatic interaction and hydrogen bond. After six cycles of desorption-adsorption, the removal efficient of MB and MV could be kept above 95%. Thus, PFPCS was considered as a highly efficient absorbent for removing cationic dyes from polluted water due to excellent adsorption characteristics, low cost and environmental friendliness.

scholarly journals DFT Analysis of NO Adsorption on the Undoped and Ce-Doped LaCoO3 (011) Surface

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1379 ◽  
Author(s):  
Xiaochen Li ◽  
Hongwei Gao
Keyword(s):  
Adsorption Energy ◽  
Density Functional ◽  
Adsorption Process ◽  
Dft Method ◽  
Adsorption Site ◽  
No Adsorption ◽  
Functional Theory ◽  
Adsorption Structure ◽  
Preferential Adsorption ◽  
The Density Functional Theory

Using the density functional theory (DFT) method, we investigated the adsorption of NO on the undoped and Ce-doped LaCoO3 (011) surface. According to our calculations, the best adsorption site is not changed after Ce doping. When the NO molecule is adsorbed on the perfect LaO-terminated LaCoO3 (011) surface, the most stable adsorption site is hollow-top, which corresponds to the hollow-NO configuration in our study. After the substitution of La with Ce, the adsorption energy of hollow-NO configuration is increased. For the perfect CoO2-terminated LaCoO3 (011) surface, it is found that Co-NO configuration is the preferential adsorption structure. Its adsorption energy can also be enhanced after Ce doping. When NO molecule is adsorbed on the undoped and Ce-doped LaO-terminated LaCoO3 (011) surface with hollow-NO configuration, it serves as the acceptor and electrons transfer from the surface to it in the adsorption process. On the contrary, for the Co-NO configuration of undoped and Ce-doped CoO2-terminated LaCoO3 (011) surface, NO molecule becomes the donor and loses electrons to the surface.

scholarly journals The Adsorption of Methylene Blue by an Amphiphilic Block Co-Poly(Arylene Ether Nitrile) Microsphere-Based Adsorbent: Kinetic, Isotherm, Thermodynamic and Mechanistic Studies

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1356 ◽  
Author(s):  
Xuefei Zhou ◽  
Mingzhen Xu ◽  
Lingling Wang ◽  
Xiaobo Liu
Keyword(s):  
Methylene Blue ◽  
Adsorption Process ◽  
Selective Adsorption ◽  
Modern Society ◽  
Influential Factors ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Cationic Dye ◽  
Solution Ph ◽  
Arylene Ether

Dye pollution is a serious problem in modern society. We desired to develop an efficient adsorbent for the decontamination of discharged dyes. In this work, the polymeric microspheres derived from a kind of amphiphilic block of co-poly(arylene ether nitrile) (B-b-S-P) were prepared on the basis of “oil-in-water” (O/W) microemulsion method. The B-b-S-P microspheres were found competent to remove the cationic dye, methylene blue (MB); and various influential factors, such as contact time, initial concentration, solution pH and temperature were investigated. Results indicated that the maximum adsorption capacity of B-b-S-P microspheres for MB was 119.84 mg/g at 25 °C in neutral conditions. Adsorption kinetics and isotherm dates were well fitted to a pseudo-second-order kinetic model and the Langmuir isotherm model, and thermodynamic parameters implied that the adsorption process was endothermic. The B-b-S-P microspheres also exhibited a highly selective adsorption for cationic dye MB, even in the presence of anionic dye methyl orange (MO). In addition, the possible adsorption mechanism was studied, suggesting that the electrostatic interaction and π–π interaction could be the main force in the adsorption process.

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