Adsorption of iron

J. C. Lobartini and G. A. Orioli, Adsorption of iron Fe-humate in nutrient. solution by plants. Plant Soil 706 153 (1988). 

A second form of storage iron is haemosiderin (Weir et al., 1984). This is deposited in humans as a response to the condition of iron overload. Haemosiderin forms as insoluble granules with electron dense cores surrounded by a protein shell. It exists in two forms primary haemosiderin is the result of iron overload due to excessive adsorption of iron in the gut, whereas the secondary form is caused by the numerous blood transfusions which are used to treat thallassaemia (a form of anaemia). Electron diffraction indicated that the iron core in primary haemosiderin is a 3-line ferrihydrite with magnetic hyperfine splitting only below 4 K and, in the secondary form, consists of poorly ordered goethite. As goethite is less soluble in ammonium oxalate buffer solution (pH 3) it has a lower intrinsic toxicity (Mann et al., 1988). 

Toxikokinetic studies showed, that the adsorption of iron blue pigments is very low. Following intravenous injection of a 59Fe-radio labelled iron blue pigment, the [59Fe(CN)6]4 ion was rapidly and virtually completely excreted with the urine. After oral administration of ferric cyanoferrate (59Fe) approx. 2% of the labelled... 

The adsorption of iron(O) pentacarbonyl was recently studied on a Si(lll)-(7 x 7) surface. The interest in Fe(CO)5 lies in its availability as a source gas for the chemical vapor deposition of FeSi2, a critical microelectronics material. Even at temperatures as low as lOOK, Fe(CO)5 already underwent dissociative adsorption to yield a linear iron monocarbonyl (FeCO) surface complex. The prominent loss peaks that appeared at 53meV (428 cm ), 81meV (653 cm ), and 255 meV (2056 cm ) were assigned to the Si-COFe, Fe-CO, and C=0 stretch modes, respectively. These peaks were shown to arise only via dipole scattering which, because of the dipole selection rule, indicates that the adsorbed FeCO is oriented vertically with the CO moiety bonded to the Si surface. 

However, this approach proved unsuccessful when applied to soil waters because of adsorption of iron hydroxides or natural organic matter to the enzyme reactor, causing rapid loss of enzyme activity. 

Fig. 23 Encapsulation of iron oxide nanoparticles in a two-step procedure electrostatic-driven adsorption of iron oxide nanoparticles onto polymer particles, followed by encapsulation of the obtained heterocoagulates by emulsion polymerization...

During the 1990s, van Veen and collaborators mainly studied the electrochemical kinetics of oxygen reduction. Their results are presented in Sect. 3. These mechanistic studies were, however, always based on the model in which the C0-N4 or Fe-N4 moieties of the respective macrocycles were retained intact at all pyrolysis temperatures. Their last contribution to the molecular structure of the catalytic site was a study in 2002 of catalysts obtained by adsorption of iron tetramethoxyphenyl porphyrin chloride (ClFeTMPP) on Vulcan XC-72, heat treated between 325 and 800°C in inert atmosphere, and characterized by EXAFS and Mossbauer spectroscopy, as well as by cyclic voltammetry". The loading of these catalysts was 7 wt% chelate ( 0.5 wt% Fe). 

Figure 3.25. PEM fuel cell polarization curves at 80°C of several MEAs made with nonnoble metal cathode catalysts. The cathode catalysts were prepared by adsorption of iron acetate (0.2 wt% Fe) on various untreated (NT) (panel a) or heat treated (T) carbon supports (panel b). The (T) carbon supports were obtained by heat beatment of (NT) carbon supports at 900°C in H2 Ar NH3 (1 1 2). The polarization curve for 5 wt% Pt/C at the cathode is given for comparison (according to Figure 3 in ref. [Ill] reproduced with permission of the American Chemical Society).

Kang, D. H, A. P. Schwab, C. T. Johnston, and M. K. Banks. 2010. Adsorption of iron cyanide complexes onto clay minerals, manganese oxide, and soil. Journal of Environmental Science and Health. Part A Toxic/Hazardous Substances Environmental Engineering 45, no. 11 1391-1396. doi 10.1080/10934529.2010.500930. 

H. Watarai and Y. Shibuya, Interfacial adsorption of iron(II)-4,7-diphenyl-l,10-phen-anthroline complex in ion-association extraction systems. Bull. Chem. Soc. Jpn., 62, 3446-3450 (1989). 

F. 16 a Cyclic voltammogiams of OPG electrodes modified by adsorption of iron porphyrins and phthalocyanines. Characterization in 0.12 M NaOH. b Rotating disk electrode voltammograms at modified electrode in presence of L-cysteine (0.5 mM). Adapted from Ref. [196]... 

Hydrochloric Acid on Alumina, 1128 Radioactive Isotope Adsorption, 1128 Adsorption of iron and Nickei Carbonyis, 1128... 

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