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Isotherms of phenanthrene adsorption on different organoclay complexes were obtained using the HPLC technique to understand the adsorption behavior and to characterize the effect of sodium chloride (NaCl) on the adsorption. The adsorbed amounts of phenanthrene on montmorillonite exchanged by organic cations such as tetraheptylammonium, benzyltrimethylammonium, hexadecyltrimethylammonium, or tetraphenylphosphonium were several times higher than those obtained using montmorillonite clay without surface modification. At the same equilibrium concentration, the adsorbed amount of phenanthrene is higher on clay modified with benzyltrimethylammonium than on clay modified with hexadecyltrimethylammonium or other cations. Adsorption of phenanthrene on clay modified with benzyltrimethylammonium increased dramatically as the concentration of NaCl increased up to 150 g/l in the aqueous solution. The shape of the curves obtained can be classified as S-type. The adsorption data obtained from salinity experiments support a mathematical model that links the Langmuir constant with the salinity constant. This model may be useful to predict the equilibrium concentration of a contaminant in saline solution. FTIR studies showed strong interactions between the aromatic rings of phenanthrene and the preadsorbed benzyltrimethylammonium on clay surfaces. 相似文献
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Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Michel Delamar Florence Babonneau Jacques Livage 《Monatshefte für Chemie / Chemical Monthly》2006,41(1):263-275
A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula
P–(CH2)3–C11H22O2N5 (where P represents [Si–O]n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional
ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the
uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). 相似文献
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Issa Mussa El-Nahhal Shehata Mahmoud Zourab Fawzi Soliman Kodeh Abeer Al-Bawab 《International journal of environmental analytical chemistry》2013,93(8):644-656
Phenol red was immobilised into a polysiloxane matrix using a sol-gel process to form pH optical sensors. The sol-gel was obtained by hydrolysis of tetraethoxysilane (TEOS) in the presence of phenol red (PR) and the appropriate surfactant. Different surfactants, namely cetyltrimethylammonium bromide (CTAB), dodecyldimetyl amino-oxide (GLA) and Triton X-100 (TX-100), were employed. Interestingly, the use of surfactants significantly improved the mesostructure of the silica and increased the porosity of the system. The two response pH ranges were shifted to pH 0.0–3.0 and pH 10.5–1.5M [OH?] compared with those of the free PR (pH 0.0–3.0 and pH 6.5–9.5). It is found that the pH response and the pKa shift of the phenol red were dependent, not only on the silica matrix but also on the ionic properties of surfactants. In the case of ionic surfactants such as CTAB or GLA, there was further shift to more acidic and more basic pH, whereas in the case of non-ionic surfactants such as TX-100 no significant change of the pH curve was observed. 相似文献
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El-Nahhal Issa M. Zaggout Farid R. Nassar Mona A. El-Ashgar Nizam M. Maquet Jocelyne Babonneau Florence Chehimi Mohamed M. 《Journal of Sol-Gel Science and Technology》2003,28(2):255-265
Porous immobilized iminodiacetic acid modified silica of the general formula S—(CH2)3—N(CH2COOH)2, (where S represents [Si—O]
n
siloxane network) has been prepared by replacement of the iodide in 3-iodopropyl modified silica with diethyliminodiacetate. The immobilized-diethyliminodiacetate ligand system (S-DIDA) was then hydrolyzed by hydrochloric acid to produce the immobilized iminodiacetic acid ligand system (S-IDA). The iodo functionalized modified silica (S-I) was prepared by polycondensation of Si(OEt)4 and (MeO)3Si(CH2)3I. The XPS and CP/MAS 13C NMR spectra showed that not all iodine atoms are replaced and that the hydrolysis of ethyl acetate groups are incomplete upon treatment with HCl. The immobilized iminodiacetic acid ligand system exhibits high potential for the uptake of various di- and trivalent metal ions such as (Mn2+, Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). Complexation of the iminodiacetate ligand system for the metal ions at the optimum conditions was found in the order: Cu2+ > Fe3+ > Ni2+ > Co2+ > Mn2+ > Zn2+. Stability studies of the iminodiacetate ligand system showed that a degradation of the siloxane network and leaching of some species occurred upon treatment with strong acid and base aqueous solutions. 相似文献
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Nizam M. El-Ashgar Issa M. El-Nahhal Mona A. Ahmed Asmah A. Abu Shaweesh Mohamed M. Chehimi 《Journal of the Iranian Chemical Society》2018,15(10):2325-2338
Immobilized-polysiloxane (diamine-thiol) tetraethylacetate, P-(NN-S)-TEA (where P represents [Si–O]n polysiloxane network), was synthesized using one-pot reaction of tetraethylorthosilicate (TEOS) with 3-(ethylenediaminetriethylacetate)propyltrimethoxysilane and 3-thiolethylacetatepropyltrimethoxysilane in the presence of cetyl trimethylammonium bromide (CTAB) as a surfactant. Its ethylenediamine and diethylenetriamine modified polysiloxane (diamine-thiol)-tetrakis(N-2-aminoethylacetamide), P-(NN-S)-TEA-NN, and polysiloxane (diamine-thiol)-tetrakis(N-diethylenediamineacetamide), P-(NN-S)-TEA-NNN chelating ligand systems were also obtained. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopic (XPS), and thermogravimetric analysis (TGA) techniques have been used for establishing their structures. An elemental CHNX combustion analyzer was used to determine the mass fractions of carbon, hydrogen, nitrogen, and sulfur of samples. The metal uptake capacities results showed that the modified polysiloxane ligand systems exhibited high capacities for the uptake of divalent metal ions in the following order: Cu2+> Pb2+> Ni2+> Co2+. 相似文献
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Hayel M. El-Kurd Issa M. El-Nahhal Nizam M. El-Ashgar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1657-1671
A new chelating porous polysiloxane-immobilized tetraacetic acid ligand system has been prepared. This material was made by chemical modification of the iminodiacetic acid polysiloxane with thionyl chloride and diethyliminodiacetate, respectively. The polysiloxane functionalized with di(amidomethyl)aminetetraacetic acid of the general formula P-(CH 2 ) 3 N(CH 2 C(O)N) 2 (CH 2 COOH) 4 [where P represents the polysiloxane backbones (Si?O?Si) n ] was characterized by Thermogravimetric Analysis (TGA) and FTIR spectra. The FTIR results proved that tetraacetic acid groups are successfully grafted onto the polysiloxane surface. This ligand system exhibits high potential for extraction of divalent metal ions (Co+2, Ni+2, Cu+2, and Zn+2) from aqueous solution. 相似文献