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1.
Etude de phosphates condenses diagramme d’equilibre du systeme AgPO3−Pr(PO3)3 Données sur AgPr(PO3)4
D. Ben Hassen-Chehimi M. Trabelsi-Ayedi 《Journal of Thermal Analysis and Calorimetry》1995,44(4):961-967
The AgPO3?Pr(PO3)3 system has been studied for the first time by differential thermal analysis, X-ray diffraction and IR spectroscopy. The system shows one compound AgPr(PO3)4 which melts in a peritectic decomposition at 1069 K. An eutectic appears at 761 K. AgPr(PO3)4 belongs to the monoclinic system with space group P2t/c,Z=4. The parameters of the unit cell are:a=12.000(9),b=13.177(4),c=7.046(5) Å and β=123o,81(6),Z=4. Its IR absorption spectrum is typical of chain phosphates. 相似文献
2.
F. Bousmina L. Zayani D. Ben Hassen-Chehimi N. Kbir-Ariguib M. Trabelsi-Ayedi 《Monatshefte für Chemie / Chemical Monthly》2003,4(10):763-768
The diagram of the ternary system Mg2+/Cl−, SO4 2−–H2O was established at 15°C by means of analytical and conductimetric measurements. Three compounds were found in this diagram, which are MgSO4·6H2O, MgSO4·7H2O, and MgCl2·6H2O. The solubility field of MgSO4·7H2O is important whereas those of MgSO4·6H2O and MgCl2·6H2O are small. The compositions (mass-%) of the two invariant points determined by the two methods are: MgSO4:MgCl2=2.73:33.80 and MgSO4: MgCl2=3.38:28.91. Both the measured and the calculated isotherm at 15°C have been used for modelling of the diagram Mg2+/Cl−, SO4 2−–H2O between 0 and 35°C. The polythermal invariant point was approximately located between 15 and 10°C. 相似文献
3.
Gam-Derouich S Gosecka M Lepinay S Turmine M Carbonnier B Basinska T Slomkowski S Millot MC Othmane A Ben Hassen-Chehimi D Chehimi MM 《Langmuir : the ACS journal of surfaces and colloids》2011,27(15):9285-9294
Homopolymer grafts from α-tert-butoxy-ω-vinylbenzyl-polyglycidol (PGL) were prepared on gold and stainless steel (SS) substrates modified by 4-benzoyl-phenyl (BP) moieties derived from the electroreduction of the parent salt 4-benzoyl benzene diazonium tetrafluoroborate. The grafted BP aryl groups efficiently served to surface-initiate photopolymerization (SIPP) of PGL. In similar conditions, SIPP of hydroxyethyl methacrylate (HEMA) permitted the production of PHEMA grafts as model surfaces. Water contact angles were found to be 66°, 15°, and 0° for SS-BP, SS-PHEMA, and SS-PPGL, respectively. The spontaneous spreading of water drops on SS-PPGL was invariably observed with 1.5 μL water drops. PPGL thus appears as a superhydrophilic polymer. Resistance to nonspecific adsorption of proteins of PPGL and PHEMA grafts on gold was evaluated by surface plasmon resonance (SPR) using antibovine serum albumin (anti-BSA). The results conclusively show that PPGL-grafts exhibit enhanced resistance to anti-BSA adsorption compared to the well-known hydrophilic PHEMA. PPGL grafts were further modified with BSA through the carbonyldiimidazole activation of the OH groups providing immunosensing surfaces. The so-prepared PPGL-grafted BSA hybrids specifically interacted with anti-BSA in PBS as compared to antimyoglobin. It is clear that the superhydrophilic character of PPGL grafts opens new avenues for biomedical applications where surfaces with dual functionality, namely, specific protein grafting together with resistance to biofouling, are required. 相似文献
4.
Hassen-Chehimi Dalila Ben Kbir-Ariguib Najia Trabelsi-Ayedi Malika 《Journal of Thermal Analysis and Calorimetry》1998,53(3):871-882
A previously established equation of a stoichiometric phase liquidus curve was applied to determination of the phase diagrams
of the systems MIPO3-Pr(PO3)3 (with MI=Na, Rb, Cs or Ag).
The temperature, enthalpy and entropy of fusion were calculated for each solid phase with the exception of silver polyphosphate,
the crystallization field of which was very limited.
The enthalpy of fusion of the polyphosphate Pr(PO3)3 was determined from the DTA curve.
The melting enthalpy of Pr(PO3)3 calculated from the different binary systems was approximately equal to the measured value. The calculated temperatures and
compositions were in good agreement with those determined experimentally.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
C. Marhag D. Ben Hassen-Chehimi H. Said 《Journal of Thermal Analysis and Calorimetry》2006,86(1):249-254
The thermodynamic
exploitation of the solid–liquid equilibria in the MIPO3–Pb(PO3)2, MIPO3–Cu(PO3)2
and MIPO3–Ce(PO3)3
systems (with M
I=Li,
Na, K, Rb, Cs, Ag, Tl) is carried out using a semi-empirical equation of the
liquidus curves already used with success for similar binary systems.
The enthalpy of fusion is calculated for each pure polyphosphate on
the assumption that the liquid solution is ideal and only formed by MIPO3
and M(PO3)q entities (q=2 for Pb and Cu, q=3
for M=Ce). In the most binary systems,
a wide difference between the calculated values of the melting enthalpies
of these polyphosphates and the measured ones determined from the DTA curves,
was observed. This difference is probably due to the existence of some molecular
associations in the liquid phase. 相似文献
6.
F. Chehimi-Moumen P. Llewellyn F. Rouquerol G. Vacquier D. Ben Hassen-Chehimi M. Ferid M. Trabelsi-Ayadi 《Journal of Thermal Analysis and Calorimetry》2005,82(3):783-789
Summary The aim of this work is the optimization of the preparation of anhydrous gadolinium hydrogen phosphate with good fluorescence
properties. The products obtained by dehydration of gadolinium hydrogen phosphate trihydrate depend on the conditions chosen
for the thermal treatment. For this reason, the dehydration was followed by Constant Rate Thermal Analysis whilst strictly
controlling the water vapour pressure above the sample. Intermediate samples, obtained during dehydration were characterised
by IR spectroscopy and X-ray diffraction. It has thus been shown that the thermal pathway taken for the dehydration depends
on the water vapour pressure above the sample in the region from 10-2to 5 mbar. Under the lowest water vapour pressure (5·10-3mbar), the elimination of the crystallization water is carried out in a continuous way and produces a quasi-amorphous intermediate.
Under higher water vapour pressure (5 mbar), well crystallized intermediate products are obtained. The results obtained suggest
that the trihydrate contains zeolitic water which confirms a prior structural study. 相似文献
7.
F. Chehimi-Moumen D. Ben Hassen-Chehimi M. Ferid M. Trabelsi-Ayadi 《Journal of Thermal Analysis and Calorimetry》2001,65(1):87-92
The preparation of a new acid lanthanide diphosphate is reported. The acid praseodymium diphosphate, obtained as a trihydrate salt, is investigated by chemical analysis, X-ray powder diffraction and IR spectroscopy. The study of the thermal behavior of HPrP2O7·3H2O shows that its dehydration begins at 367 K. A scheme of its decomposition is proposed.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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9.
F. Bousmina-Henchi D. Ben Hassen-Chehimi M. Trabelsi-Ayadi 《Phosphorus, sulfur, and silicon and the related elements》2016,191(8):1108-1113
A new ytterbium diphosphate: HYbP2O7·4H2O was prepared via soft chemistry route from evaporation of aqueous solution. It was investigated by single crystal X-ray diffraction, vibrational spectroscopy, and thermal analysis.The framework of the title compound consists in an assemblage of HP2O7 groups and [YbO5(H2O)2] polyhedra, giving rise to corrugated layers stacked along the b axis at y = 1/4 and y = 3/4. Between these layers are located two uncoordinated water molecules. The cohesion of this arrangement is well ensured by a three-dimensional network of water-layer and inter-layer hydrogen bonds of different strengths. Non-coincidences are observed between the majority of the IR and Raman bands and confirm a centrosymetric structure for this compound. Thermal analysis reveals the elimination of 4.5 water molecules per formula unit in three stages between 310 K and 1100 K, which correspond to the departure of the four crystallization water molecules and the OH group. A comparative study among hydrated lanthanide monohydrogendiphosphates known in the literature is presented. 相似文献
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