Adsorption of aniline

O Brien, J., Curtin, T., and O Dwyer, T.F. (2005) An investigation into the adsorption of aniline from aqueous solution using H-beta zeolites and copper-exchanged beta xeolites. Adsorpt. Sd. Technol, 23, 255. 

Adsorption of aniline on Cui xZnxFc204 at <100°C indicates a simple molecular adsorption through N-atom on an acid-base pair site. However, above 100°C, N-H bond dissociates and aniline chemisorbed strongly on the catalyst surface. Chemisorbed aniline... 

Polyaniline has been formed in the pores of Cu- or Fe-exchanged MCM-41 by adsorption of aniline vapour and subsequent oxidative polymerization (Figure 7.23), and these molecular wires demonstrate significant electronic conduction, although less than that of bulk polyaniline. Pyrolysis of polyacrylonitrile in the pores produces a graphitelike carbon chain, which exhibits microwave conductivity ten times that of bulk carbonized polyacrylonitrile. Such materials have potential for use in information processing as storage capacitors. 

Adsorption of aniline on minerals, such as kaolinite, montmorillonite and vermiculite as well as on a-alumina and iron powders, has been studied in order to better understand the interaction of the adsorbate with natural adsorbents154-157. However, the results, similarly to those obtained on a smooth polycrystalline platinum electrode158, are not useful for the removal of aniline from waste water. The commonly used activated charcoal is also deficient owing to slow kinetics of the removal of dissolved pollutants. In this situation, activated carbon fibers, woven as a C-cloth, seem to be the ideal adsorbents for removal of aniline from waste streams. The reports of Niu and Conway159,160 explained the adsorptive and electrosorptive behavior of aniline on C-cloth electrodes and suggested a methodology for clean-up of industrial waste waters. 

This equation has rarely been reported as accoimting well for a set of experimental data. The adsorption of aniline on Kromasil Cig is a case in point [11,32], see Figure 3.11. Chromatographers seem to prefer the Langmuir model and rarely try to use this alternative. Accurate data acquired in a wide range of concentrations are needed to show that one of the two models is significantly better than the other... 

Radovic and coworkers [38] recently investigated the effects on the adsorption process of the pH and the nature of the functional groups on the aromatic adsorptive and the adsorbent. For this purpose, they used an as-received activated carbon oxidized with nitric acid and nitrided with ammonia to study the adsorption of aniline and nitrobenzene, which are, respectively, electron-donating and electron-withdrawing groups. Results found by these authors, together vidth... 

McCarthy and coworkers126 229 reported a template-guided synthesis of water-soluble chiral PAn nanocomposites. The nanoparticles were prepared by the physical adsorption of aniline monomer onto a templating poly(acrylic acid) in the presence of (+)- or (-)-CSA, followed by chemical oxidation. Using this approach, optically active nanocomposites of approximately 100 nm diameter were formed. Earlier work by Sun and Yang230 using polyelectrolytes produced similar nonchiral dispersions in which the PAn chain is interwound with a water-soluble polymer by electrostatic forces.231 Similar work by Samuelson and coworkers utilized DNA as a chiral template for PAn.232... 

An elaboration of this technique, incorporating the concept of template-guided synthesis, is the use of nanoporous matrices such as zeolites and polycarbonates as a template within whole pores to perform the chemical polymerization of aniline monomers. For example, Wu and Bein254 have prepared nanofilaments of conducting PAn in the 3-nm-wide channels (pores) of the aluminosilicate host, MCM-41, through initial adsorption of aniline vapor into the dehydrated host followed by oxidation with (NH)2S208. 

The substance to be selectively adsorbed from a mixture can depend on experimental conditions. For example, from a mixture of aniline and phenol, a high pH will favor the adsorption of aniline, whereas a low pH will cause preferential adsorption of phenol. Similarly, temperature can produce diverging effects raising the temperature increases the adsorption of glycerophosphate but simultaneously diminishes that of sucrose. 

ADSORPTION OF ANILINE FROM SOLUTION OF ANILINE HYDROCHLORIDE ... 

Molasses adsorption based on color unit scale adsorption of Aniline Blue expressed as g/g carbon ai an equilibrium solution concentration of 0.10 g/liter. 

Alkalimetric and acidimetric methods are not to be used because of interference from acids or bases in some carbons. The effect is illustrated by an experience with a test that involved the adsorption of aniline. As first conducted, the residual unadsorbed aniline was measured by a specific chemical test. The method was tedious, however, and it was thought the procedure could be shortened and simplified by titrating the unadsorbed aniline with an acid. But the residual aniline thus measured often differed from that measured by the specific chemical test. The deviations were traced to the presence of free acid on some carbons and free alkali on others. Carbons with a high pH gave a false high residual aniline, whereas carbons of low pH showed a false low residual concentration of aniline. Similar experiences are reported in the use of acidimetry and alkalimetry to measure the adsorption of other substances. 

Abridged data on such a study appear in Table 14 5. Inspection of the table discloses that the adsorption of aniline blue closely parallels the M-RE hence if the M-RE is being used nothing will be gained by adding the test with Aniline Blue. 

The formation of filaments of PANI was also achieved using MCM-41 as a template [86,87]. MCM-41 is a synthetic aluminosilicate, with hexagonal arrays of holes ca. 3.0 nm in size. Nanocomposites of PANI-MCM-41 were synthesized by exposure of MCM-41 containing ions of Cu (II) or Fe (III) to vapors of aniline [88]. The adsorption of aniline... 

C. J. Murphy et al., Photolmninescence-Based Correlation of Semiconductor Electric Field Thickness with Adsorbate Hammett Substituent Constants. Adsorption of Aniline Derivatives onto Cadmimn Selenide, J.Am. Chem. Soc. 1990, 112, 8344-8348. 

Polymer-clay nanocomposites using PANI and PPy exhibit better electrical behavior than PEO-clay systems, but in these cases the conductivity is electronic. These nanocomposites are prepared, as discussed earlier (Sec. V.B), by interla-mellar adsorption of aniline or pyrrole in smectites saturated with transition metal... 

Other work abstracted has included the adsorption of the dyes crystal violet and malachite green on vermiculite the adsorption of aniline and p-... 

Guo K, Chen Y (2010) Simple and rapid detection of aromatic amines using a thin layer chromatography plate. Anal Methods 2 1156-1159. doi 10.1039/C0AY00316F Haas R, Schmidt TC, Steinbach K, Von Low E (1997) Derivatization of aromatic amines for analysis in ammunition wastewater II derivatization of methyl anilines by iodination with a Sandmeyer-fike reaction. Fresenius J Anal Chem 359 497-501 HanY, QuanX, Chen S, Zhao H, Cui C, Zhao Y (2006) ElectrochemicaUy enhanced adsorption of aniline on activated carbon fibers. Sep Purif Technol 50 365-372. doi 10.1016/j. seppur.2005.12.011... 

Wu YG, Hui L, Li X, Zhang YZ, Zhang WC (2007) Degradation of aniline in weihe riverbed sediments under denitrification conditions. J Environ Sci Health, Part A Tox Hazard Subst Environ Eng 42(4) 413-419. doi org/10.1080/10934520601187302 Yadav S, Tyagi DK, Yadav OP (2011) EquiUbrium and kinetics studies on adsorption of aniline blue from aqueous solution onto rice husk carbon. Int J Chem Res 2(3) 59-64 Yang J, Tsai FP (2001) Development of a solid-phase microextraction/reflection-absorption infrared spectroscopic method for the detection of chlorinated aromatic amines in aqueous solutions. Anal Sci 17 751-756... 

Yang K, Wu W, Jing Q, Zhu L (2008) Aqueous adsorption of aniline, phenol, and their substitutes by multi-walled carbon nanotubes. Environ Sci Tech 42 7931-7936. doi 10.1021/es801463v Ye S, Huang F (2007) Separation of carcinogenic aromatic amines in the dyestuff plant wastewater treatment. Desalination 206 78-85. doi 10.1016/j.desal.2006.03.562 Yemashova N, Kalyuzhnyi S (2006) Microbial conversion of selected azo dyes and their breakdown products. Water Sci Technol 53(11) 163-171. http //www.ukpmc.ac.uk/abstract/MED/ 16862786... 

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