共查询到20条相似文献,搜索用时 15 毫秒
1.
Surface-enhanced micro-Raman detection and characterization of calix[4]arene-polycyclic aromatic hydrocarbon host-guest complexes 总被引:1,自引:0,他引:1
Leyton P Sanchez-Cortes S Campos-Vallette M Domingo C Garcia-Ramos JV Saitz C 《Applied spectroscopy》2005,59(8):1009-1015
Surface-enhanced micro-Raman spectroscopy (micro-SERS) was used to detect traces of the hazardous pollutant polycyclic aromatic hydrocarbons (PAHs) pyrene and benzo[c]phenanthrene deposited onto a calix[4]arene-functionalized Ag colloidal surface. High spectral reproducibility and very low molecular detection limits (10(-8) M) were obtained by using 25,27-carboethoxy-26,28-hidroxy-p-tert-butylcalix[4]arene as host molecule. Films of immobilized aggregated Ag nanoparticles, obtained by chemical reduction with hydroxylamine, were prepared by direct adhesion on a glass surface. The influence of the aggregation degree of the initial Ag nanoparticles on the micro-SERS detection effectiveness was checked. Different relative concentrations of the host (calixarene receptor) and the guest (PAHs) were attempted in order to optimize detection of the pollutant. The obtained results indicated that the detection limit is much lower in the case of benzo[c]phenanthrene than in pyrene when exciting with the 785 nm line of a diode laser. A detailed interpretation of the Raman spectra was accomplished in order to obtain more information about the interaction mechanism of the host-guest complex, which could be useful in the future for the design of powerful detection systems. 相似文献
2.
Nadjib Benosmane Bouzid Guedioura Safouane Mohammed Hamdi Maamar Hamdi Baya Boutemeur 《Materials science & engineering. C, Materials for biological applications》2010,30(6):860-867
A polymer inclusion membrane (PIM) system with cellulose acetate polymer as support and calix[4]resorcinarenes as carriers has been developed. Special attention was paid to PIM characterization using scanning electron microscopy, Fourier-transform infra-red study, X-ray scattering and thermogravimetric analyses. The efficiency of the membrane transport was optimized as a function of pH, stirring speed, aqueous phases and membrane composition. The results suggested that the transport mechanism is a counter-transport of protons, the mechanism was mainly controlled by the diffusion of the complex formed in the membrane core. Analysis of lead(II) transport through these PIMs was performed. It was found that calix[4]resorcinarenes containing membranes were flexible, resistant and heterogeneous without plasticizer addition. 相似文献
3.
Muhammad Afzal Kamboh Imam Bakhsh Solangi S.T.H. Sherazi Shahabuddin Memon 《Journal of hazardous materials》2009,172(1):234-239
The present study describes a novel synthetic method for the immobilization of calix[4]arene (II) onto the surface of modified Amberlite XAD-4 resin (4), which does not require the derivatization of calixarene moiety. The novel calix[4]arene based resin (C4 resin) 5 was used as sorbent for the removal of azo dyes. Batch-wise sorption study was carried out and observed that the C4 resin (5) is more effective as compared to compound II as well as pure Amberlite XAD-4 resin (1) to remove the selected dyes [i.e. Reactive Black-5 (RB-5), Reactive Red-45 (RR-45) and Congo Red (CR)]. The effect of sorbent dosage and pH on % sorption was studied. During the extraction process, various kinds of interactions such as electrostatic repulsion, deprotonation of the hydroxyl groups of C4 resin, dissociation of reactive dyes into anions/cations and structural variations were monitored and found that they are highly pH dependent. 相似文献
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In this paper, the adsorbents were prepared from cellulose-grafted with calix[4]arene polymers (CGC[4]P-1 and CGC[4]P-2) and their sorption properties studied. The polymers were characterized by Fourier transform infrared spectroscopy, elemental analysis, thermal gravimetric analysis and scanning electron microscopy. They were then used to evaluate the sorption properties of some heavy metal cations (Co(2+), Ni(2+), Cu(2+), Cd(2+), Hg(2+) and Pb(2+)) and dichromate anions (Cr(2)O(7)(2-)/HCr(2)O(7)(-)). Results showed that CGC[4]P-2 was a good sorbent for heavy metal cations while CGC[4]P-1 was ineffective. In the studies of dichromate anion sorption, it was observed that CGC[4]P-2 was a more highly effective sorbent at pH 1.5 than was CGC[4]P-1. 相似文献
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meso-Octamethylcalix[4]pyrrole (CP) and meso-heptaethylcalix[4]pyrrole-meso-4-aminophenyl (4APCP) modified glassy carbon (GC) electrodes were prepared by the electrochemical oxidation in acetonitrile solution. Binding of the calix[4]pyrroles with the glassy carbon surface was investigated that it is through the etheric linkage revealed from the reflection-absorption infrared spectroscopy (RAIRS). Surface films of CP and 4APCP were investigated by cyclic voltammetry (CV), ellipsometry, X-ray photoelectron spectroscopy, RAIRS and the contact angle measurements. The thicknesses of the films were determined by ellipsometry which confirmed that the film was multilayer and homogeneous over the surface. Ellipsometric measurements also provided that the CP and 4APCP film thicknesses were 2.49 nm and 4.58 nm for 6 CV cycle modification, corresponding to 66 μF/cm2 and 106 μF/cm2 capacitances obtained by CV. The wetting behavior was examined by contact angle measurements and found that the hydrophobicity of the GC-4APCP surface was higher than that of GC-CP, probably due to the aromatic meso substituent present in the former. 相似文献
8.
N. S. Almodóvar R. Font J. Portelles O. Raymond E. Martínez J. M. Siqueiros 《Journal of Materials Science》2003,38(14):3085-3088
A study of the calcination and sintering processes of 0.5PMN-0.5PFN ceramics prepared starting from the specifically designed precursor compound [Fe0.6, Mg0.4]NbO4, is presented. The microstructural characteristics are determined using X-ray diffraction and scanning electron microscopy. The resulting dielectric properties of the PMN-PFN samples thus obtained were very good when compared with those reported in the literature, for samples prepared at higher calcination temperatures. The dielectric properties as functions of temperature and the hysteresis loops (P vs. E) under different external applied electric fields are reported. 相似文献
9.
BACKGROUND: Bioactive and biodegradable polyurethanes (BDPUs) have drawn much attention in recent years. As part of the research program to search for novel prepolymers for BDPUs, a study was carried out on the synthesis and characterization of triblock copolymers comprising poly(tetrahydrofuran) as a central block and poly(?-benzyl L-glutamate)s as outer blocks. RESULTS: A new macroinitiator terminated with phenylalanine was first prepared from the condensation of a distal hydroxy poly(tetrahydrofuran) with N-tert-butoxycarbonyl L-phenylalanine in the presence of dicyclohexylcarbodiimide, followed by removing the protecting group. Then, it was employed to initiate the ring-opening polymerization of ?-benzyl L-glutamate N-carboxyanhydride in varying feeding ratios to give rise to the targeted triblock copolymers. CONCLUSIONS: The length of the outer poly(?-benzyl L-glutamate) blocks was well tailored by varying the monomers to macroinitiator feeding ratio. All the triblock copolymers exhibited a nearly symmetrical and unimodal molecular weight distribution while only one distinct glass transition temperature was evidenced from -10°C to 25°C. 相似文献
10.
2-炔丙基-4-[4-N,N-二乙基苯偶氮基]苯甲酸酯的合成、表征及光限幅性能 总被引:4,自引:0,他引:4
使用二环己基碳酰亚胺(DCC)和N,N-二甲基吡啶(DMAP)催化合成了非线性生色化合物2-炔丙基-4-[4-N,N-二乙基苯偶氮基]苯甲酸酯(PBAB)。与酸催化等法进行比较,DCC/DMAP催化法具有反应条件温和、产率高的优点。用紫外、红外、核磁和元素分析对化合物结构进行表征。测定了其光限幅性能,在低入射激光光强时,透射光强度随入射光强度增加而增加:当入射光强度达151.4GW/cm^2透射光强开始偏离线性,呈现非线性光限幅效应。对其限幅机制进行了分析,结果显示产物对1064nm波长激光的限幅机制主要是双光子吸收机制。 相似文献
11.
He L Yao L Liu F Qin B Song R Huang W 《Journal of nanoscience and nanotechnology》2010,10(10):6348-6355
A novel method was developed to prepare Fe3O4@CS beads with core-shell structure using a double-crosslinking process. Before the coating process, an unique crosslinking agent, glutaraldehyde (GA), was adsorbed onto the surface of Fe3O4 in advance, so the subsequent CS can uniformly coat around the magnetic core processed from the strong interaction between GA and CS, forming a perfect core-shell structure. The obtained Fe3O4@CS beads were followed by the Pd deposition through in-situ reduction method, and the prepared composite catalyst was applied exemplarily in synthesizing nabumetone to check its reusing property. The nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and the magnetic hysteresis loop determination method. This novel composite catalyst showed admirable potential in reusable catalysis. 相似文献
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A fluorogenic derivative of 1,3-alternate calix[4]arenebis(crown-6) (1) containing a dansyl group in the proton-ionizable side arm has been employed in selective sensing of Tl+ and Cs+ at low concentration levels in MeCN-H2O (1:1) mixed solvent. Optical recognition of these two metal cations by 1 occurs in contrasting modes. On the basis of the results of fluorescence, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 1H NMR studies, Tl+ and Cs+ react with 1 via formation of 1:1 complexes that differ in coordination arrangement around the metal ion. 相似文献
13.
Tsuda D Nakahara Y Machitani K Kannaka M Takahashi E Kimura K 《Analytical chemistry》2012,84(8):3710-3715
A novel flow injection analysis (FIA) system for ultra-high-sensitive determination of Na(+), which involves laser interferometric photothermal equipment as the detector, was designed using a proton-dissociable chromogenic calix[4]arene derivative with a dinitrophenol moiety as the extraction-photometric reagent. The chromogenic calix[4]arene derivative showed an excellent extractability toward Na(+), which reflected the cation-complexing property of the tetraethyl ester derivative of calix[4]arene. As the calibration graph of the Na(+) concentration could be successfully obtained at the nanomolar level by this method, the proposed FIA system was found to be promising for highly sensitive determination of Na(+) in very dilute samples such as supply water and cooling water in power plants. 相似文献
14.
Thangamani Rajkumar Chinnaswamy Thangavel Vijayakumar 《Fullerenes, Nanotubes and Carbon Nanostructures》2017,25(7):442-448
Functionalization of graphene oxide leads improvement in thermal stability and flame retardancy. Acid chloride terminated N-[4-(chlorocarbonyl)phenyl]maleimide (Cl-CPMI) was synthesized to decorate hydroxyl group in graphene oxide (GEO) and glycine-reduced GEO (RGEO). Structural characterization of the materials was performed using FTIR, 13C NMR and Raman spectroscopic methods. Interlayer distance and surface morphology were also studied using X-ray diffraction and scanning electron microscopic methods, respectively. The absence of the band for C-Cl and shortening of the O-H band in the FTIR and peak in 13C NMR spectra confirm the functionalization of alcoholic group on the graphitic plane with Cl-CPMI. The ratio, ID/IG computed from Raman study, the nature of XRD pattern and interlayer distance between the adjacent graphitic layers were not affected by the functionalization of GEO and RGEO using Cl-CPMI. The tagging of maleimide unit with the graphitic plane was also confirmed by the cloudy appearance in the SEM images. 相似文献
15.
《Materials Research Bulletin》2006,41(7):1287-1294
Chemical preparation, crystal structure and NMR spectroscopy of a new organic cation p-phenylenediammonium monophosphate [p-NH3C6H4NH3][H2PO4]2 are presented. This new compound crystallizes in the orthorhombic system, with the space group Pnma and the following parameters: a = 7.970 (2) Å; b = 22.770 (7) Å; c = 7.000 (7) Å, V = 1270.3 (11) Å3, Z = 4 and Dx = 1.590 g cm−3. The crystal structure has been determined and refined to R = 0.043 and R(w) = 0.057 using 2623 independent reflections. The structural arrangement can be described as inorganic layers of (H8P4O16)4− units, parallel to (a, c) planes. The organic groups (p-H3NC6H4NH3)2+are anchored between the phosphoric layers to form a three-dimensional infinite network. This compound is also investigated by IR and solid-state 1H, 13C and 31P MAS NMR spectroscopies. The ab initio method is used in the calculation of chemical shifts. 相似文献
16.
M.G.S.R. Thomas W.I.F. David J.B. Goodenough P. Groves 《Materials Research Bulletin》1985,20(10):1137-1146
Room-temperature electrochemical extraction of lithium from nearly stoichiometric, layered LiNiO2 gives the solid-solution system Li1?xNiO2. Monitoring the temperature dependence of the X-ray-diffraction pattern of Li0.5NiO2 has revealed a first-order transformation above 150°C to the cubic, normal spinel phase Li[Ni2]O4. This spinel phase is stable to 300°C 相似文献
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Yu YY 《Journal of nanoscience and nanotechnology》2010,10(8):5354-5358
In this study, polythiophene based rod-coil block copolymers (P3HT)47-b-(PMSMA)34 are synthesized by atom transfer radical polymerization (ATRP). The effects of altering the mix of solvent and processing temperature on the morphologies and photophysical properties of the block copolymers in both solution and solid state are investigated. The chemical structure of the prepared block copolymers is confirmed by NMR and FTIR analysis. TEM results show that different morphologies of aggregates can be obtained by varying the toluene/methanol ratios. Such aggregation leads to a significant red shift on the optical absorption and photoluminescence spectra of the P3HT-b-PMSMA in mixed solvents. The results of AFM, UV-Vis, and PL show that the morphologies and photophysical properties of P3HT-b-PMSMA films are also significantly affected by the curing temperature. Blue shifts on the optical absorption and photoluminescence spectra are observed upon increasing the curing temperature. 相似文献
19.
Sorption characteristics of Cu(II) ions onto silica gel-immobilized calix[4]arene polymer in aqueous solutions: batch and column studies 总被引:2,自引:1,他引:1
In the present study, Cu(II) removal from aqueous solutions by sorption was investigated. Aminopropyl silica gel-immobilized calix[4]arene polymer (APSIC[4]P) was used in sorption as sorbent. During the experimental part of this study, the effect of parameters, such as pH, initial Cu(II) concentration, temperature on Cu(II) removal was observed. In addition, sorption isotherm studies and column studies were made. Maximum Cu(II) removal was obtained at pH 6 and 25 degrees C. In the isotherm studies, Langmuir and Freundlich isotherm models were applied and it was determined that the experimental data confirmed to Langmuir isotherm model. Batch sorption capacity (q0) was calculated as 5.08 mg/g. The capacity value for column study was obtained by graphical integration as 1.14 mg/g. The Thomas and the Yoon-Nelson models were applied to experimental data to predict the breakthrough curves and to determine the characteristics parameters of the column useful for process design. 相似文献
20.
采用水热法合成高质量的Fe4[Fe(CN)6]3(HQ-FeHCF)纳米材料, 并对材料进行X射线衍射(XRD), 扫描电子显微镜(SEM), 透射电子显微镜(TEM)和热重分析测试(TGA)等表征。结果表明:Fe4[Fe(CN)6]3呈规则立方体, 颗粒大小约500 nm, 属面心立方结构。Fe4[Fe(CN)6]3在NaClO4-H2O-聚乙二醇电解液中1C、2C、5C、10C、20C、30C和40C的容量分别为124、118、105、94、83、74和64 mAh·g -1, 表现出优异的倍率性能; 以5C倍率循环500次, 容量保持率接近100%, 表现出极佳的循环稳定性。以Fe4[Fe(CN)6]3和磷酸钛钠分别为正负极的全电池工作电压高达1.9 V, 能量密度可达126 Wh·kg -1; 以5C倍率恒流充放电测试140次后全电池容量保持率为92%, 且库伦效率始终接近100%。 相似文献