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We present here coadsorption data of ethylmercaptan with n-heptane or toluene on NaX at 298 K in the aim to use this adsorbent for removing mercaptans from natural gas. Results show that NaX has an adsorption affinity for sulphur compound strong enough to perform a deep desulphurization. NaX adsorbs preferentially ethylmercaptan over a large domain of pore filling. A displacement of n-heptane by ethylmercaptan is even observed. However, toluene becomes preferentially adsorbed at high filling. The dependence of filling and composition on selectivities and failed prediction of coadsorption equilibria by the IAS Theory indicate that the adsorbed mixture behaves as a non-ideal solution. Calorimetric measurements of coadsorption heats show that the coadsorption process is not governed by enthalpic effects but by entropic effects consecutive to steric hindrance of molecules in confined spaces. 相似文献
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H. Bahaj M. Bakass C. Bayane J. P. Bellat M. Benchanaa G. Bertrand 《Journal of Thermal Analysis and Calorimetry》2011,103(1):117-123
The adsorbed amounts of water vapor onto polyacrylic polymer (polymer ×10) were measured using a thermogravimetry method as
a function of pressure at 298 and 313 K. The adsorption isotherms are categorized to type II isotherms by IUPAC classification
leading to a hysteresis loop between adsorption and desorption branches. The current study was completed by the measurement
of the adsorption heats at 298 K using a differential scanning calorimetry. The calorimetric curves showed two adsorption
heats domains. These domains have been attributed to the adsorption of “equivalent monolayer” and the condensation of water
between polymeric chains. The correlation of experimental data to some chosen theoretical models shows that the GAB model
is the most adequate to describe water vapor sorption isotherms. 相似文献
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Ashish Kadam Thomas Karbowiak Andree Voilley Jean‐Pierre Bellat Olivier Vitrac Frederic Debeaufort 《Journal of Polymer Science.Polymer Physics》2014,52(19):1252-1258
Sorption properties of pure n‐hexane vapor in amorphous polystyrene (PS) were studied at 298 K by thermogravimetry under controlled vapor pressure. Two sorption–desorption cycles were performed by varying the relative pressure between 0 and 0.91. Mixing of PS with n‐hexane resulted in a strong plasticization, which was evidenced by quite significant depression in the glass transition temperature of the polymer as shown by differential scanning calorimetry. Maximum quantity of n‐hexane sorbed in the PS at 298 K and at a pressure close to saturation was about 12.4 wt %. The thermogravimetry yielded an isotherm with a strong hysteresis loop, explanation of which was hypothesized with the help of (a) Flory–Huggins sorption model extended by Vrentas, (b) analysis in terms of modification in the glass transition temperature of the n‐hexane/PS system as a function of sorbed quantity, and (c) change in total volume of the system. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1252–1258 相似文献
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Simon JM Bellat JP Vasenkov S Kärger J 《The journal of physical chemistry. B》2005,109(28):13523-13528
The sticking coefficient, i.e., the probability that, on hitting the surface of a nanoporous particle (zeolite), a molecule shall be able to enter the intracrystalline space, is a key quantity for the application of such materials in heterogeneous catalysis and molecular sieving. On the basis of pulsed field gradient NMR diffusion measurements and molecular dynamics simulations, typical values of this probability are found to be close to one. They exceed previous estimates on the basis of IR uptake measurements by many orders of magnitude. 相似文献
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Supramolecular Open‐Framework of a Bipyridinium‐Carboxylate Based Copper Complex with High and Reversible Water Uptake 下载免费PDF全文
Maxime Leroux Guy Weber Jean‐Pierre Bellat Igor Bezverkhyy Nicolas Mercier 《无机化学与普通化学杂志》2016,642(24):1439-1444
The rigid zwitterionic ligand 1,1′‐bis(4‐carboxylatphenyl)‐(4,4′‐bipyridinium) (pc1) and copper(II) ions give rise to a linear complex [Cu(pc1)2(H2O)4]2+, which self assembles in a pseudo tetragonal supramolecular arrangement leading to the supramolecular open‐framework [Cu(pc1)2(H2O)4](Cl)2 · 8H2O exhibiting an open structure including water molecules and chlorides in pores. The dehydration of this material occurs at relatively low temperature (70 °C) and results in structure modification accompanied by shrinking of the crystals. Characterization of the obtained material by FT‐IR spectroscopy reveals appearance of coordinated carboxylates groups, which may indicate the formation of coordination polymer after dehydration. Water adsorption (maximum uptake 0.23 g H2O per g) on dehydrated material allows to restore the initial structure. A large hysteresis in water adsorption‐desorption isotherm is characteristic of a significant modification of the structure during the hydration‐dehydration cycle which is in line with the structural transition determined from thermodiffractometry and FT‐IR spectroscopy. 相似文献
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Dr. Nans Roques Dr. Georges Mouchaham Dr. Carine Duhayon Dr. Stéphane Brandès Aurélie Tachon Dr. Guy Weber Prof. Dr. Jean Pierre Bellat Dr. Jean‐Pascal Sutter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(37):11690-11694
Hydrogen‐bond assembly of tripod‐like organic cations [H3‐MeTrip]3+ (1,2,3‐tri(4′‐pyridinium‐oxyl)‐2‐methylpropane) and the hexa‐anionic complex [Zr2(oxalate)7]6? leads to a structurally, thermally, and chemically robust porous 3D supramolecular framework showing channels of 1 nm in width. Permanent porosity has been ascertained by analyzing the material at the single‐crystal level during a sorption cycle. The framework crystal structure was found to remain the same for the native compound, its activated phase, and after guest resorption. The channels exhibit affinities for polar organic molecules ranging from simple alcohols to aniline. Halogenated molecules and I2 are also taken up from hexane solutions by this unique supramolecular framework. 相似文献
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Interaction Mechanisms between guaiacols and lignin: the conjugated double bond makes the difference
Barrera-García VD Chassagne D Paulin C Raya J Hirschinger J Voilley A Bellat JP Gougeon RD 《Langmuir : the ACS journal of surfaces and colloids》2011,27(3):1038-1043
Lignin is considered to be responsible for a selective sorption of phenolic compounds on wood. In order to investigate the mechanisms involved, two similar guaiacol compounds--only differing by the nature of the para side chain--were adsorbed on oak wood extracted lignin. Vapor sorption-desorption isotherms indicated that about 3.5 wt % of 4-vinylguaiacol is adsorbed near saturation whereas it is only 0.8% for 4-ethylguaiacol. For both compounds, the isotherms displayed a hysteresis though significantly greater for 4-vinylguaiacol. Analyses of the hydroxyl stretching region of FTIR spectra of the lignin/4-ethylguaiacol and lignin/4-vinylguaiacol complexes indicated that physisorption via hydrogen bonds occurs for both sorbates with lignin phenolic hydroxyl groups but which would be more condensed for the former than for the latter. According to NMR spectra, these phenolic hydroxyl groups correspond to non-etherified guaiacyl subunits. In contrast with other para substituents, the conjugated vinyl bond favors not only physisorption but also chemisorption as witnessed by the fact that upon desorption in the vapor phase, even after pumping under dynamic vacuum for several days, about 1 wt % of 4-vinylguaiacol remains adsorbed onto lignin. 相似文献