Iron colloidal

In contrast to the reaction with lithium amide, the sodium amide suspension immediately settles out after stopping the stirring and the supernatant ammonia has a grey or black colour, due to colloidal iron. In some cases it took a long time before all of the sodium had been converted (note 4). A further 0.1 g of iron(III) nitrate was then added to accelerate the reaction and some liquid ammonia was introduced to compensate for the losses due to evaporation. 

Most commercial liquid ammonia contains up to several ppm of colloidal iron compounds, possibly the iron oxide catalyst commonly used in manufacturing ammonia. Reduction converts these compounds to colloidal iron which strongly catalyzes the reaction between alcohols and sodium and potassium. The reaction of lithium with alcohols is also catalyzed by iron but to a markedly lesser degree. The data in Table 1-4 illustrate the magnitude of these catalytic effects. The data of Table 1-5 emphasize how less than 1 ppm... 

Some acrylic acid copolymers are promoted as having a very wide range of functions that permit them to act as calcium phosphate DCAs, barium sulfate antiprecipitants, particulate iron oxides dispersants, and colloidal iron stabilizers. One such popular copolymer is acrylic acid/sulfonic acid (or acrylic acid/ 2-acrylamido-methylpropane sulfonic acid, AA/SA, AA/AMPS). Examples of this chemistry include Acumer 2000 (4,500 MW) 2100 (11,000 MW) Belclene 400, Acrysol QR-1086, TRC -233, and Polycol 43. 

Acrylic acid terpolymers have appeared on the market in recent years. With their broad spectrum of functions, they offer the potential for excellent waterside conditions. In particular, the terpolymers have proved to be very effective particulate iron oxides dispersants and colloidal iron stabilizers. Examples include acrylic acid/sulfonic acid/sodium styrene sulfonate (AA/SA/SSS), such as Good-Rite K781, K797, K798. A further example is acrylic acid/ sulfonic acid/substituted acrylamide (AA/SA/NI), such as Acumer 3100. 

Consequently, when selecting and blending the various raw materials used in all-polymer/all-organic formulations, the questions of thermal and hydrolytic stability and ability to transport or otherwise control colloidal iron oxides (in addition to possible adverse effects such as copper corrosion) become increasingly important at higher boiler temperatures and pressures. 

Aslant M, Schultz EA, Sun T, Meade T, Dravid VP (2007) Synthesis of amine-stabilized aqueous colloidal iron oxide nanoparticles. Cryst Growth Design 7(3) 471 175... 

Under relevant conditions (neutral pH, presence of carbonate) the concentrations of dissolved trace metals are limited by the solubility of their solid hydroxides or carbonates. A prominent example is the solubility of Fe(III), which is very low (around 10 10 mol dm 3) under relevant conditions of fresh water or seawater at neutral pH [96]. Iron(III) occurs primarily as solid or colloidal iron hydroxide at neutral pH. 

On the other hand, the uptake of colloidal iron has been studied in greater detail. For example, some bacteria have been demonstrated to reduce ferric oxide particles to increase iron bioavailability [341,342], As was observed in Section 5.2.4, Fe reaction kinetics with metal carriers are thought to be rate-limiting. In the presence of colloidal iron, the thermodynamic stability or... 

Nodwell, L. M. and Price, N. M. (2001). Direct use of inorganic colloidal iron by marine mixotrophic phytoplankton, Limnol. Oceanogr., 46, 765-777. 

Waite, T. D., and F. M. M. Morel (1984), "Photoreductive Dissolution of Colloidal Iron Oxide Effect of Citrate," J. Colloid Interface Sci. 102, 121-137. 

Colloids Organic Colloids Inorganic Colloids iron oxyhydroxides... 

Maruthe,V.R. Trautwein, A. (1983) Calculation of charge density, electric field gradient and internal magnetic field using molecular orbital cluster theory. In Thosar, B.V. (ed.) Advances in Mossbauer spectroscopy. Elsevier, Amsterdam, 398-449 Matijevic, E. Cimas S. (1987) Formation of uniform colloidal iron(lll) oxides in ethylene... 

Mayer, L.M. (1982) Aggregation of colloidal iron during estuarine mixing Kinetics, mechanism, and seasonality. Geochim. Cosmochim. Acta 46 2527-2535... 

Meisel, D. (1990) Effect of the potential on electron transfer to colloidal iron oxide. Langmuir 6 555-559... 

Waite, TD. Morel, E.M.M. (1984) Photoreduc-tive dissolution of colloidal iron oxide Effect of citrate. J. Colloid Interface Sci. 102 121-... 

Waite, T.D. Torikow, A. Smith, J.D. (1986) Photoassisted dissolution of colloidal iron oxides by thiol-containing compounds. 1. Dissolution of hematite (a-Pe203). J. Colloid Interface Sci. 112 412-420 Walcott, C. Gould, J.L. Kirschvink, J.L. (1979) Pigeons have magnetic remanence. Science 205 1027-1028... 

Zhang,Y Kallay, N. Matijevic, E. (1985) Interactions of metal hydrous oxides with chelating agents. VII. Hematite - oxalic and citric acid systems. Langmuir 1 201-206 Zhang, Z. Boxall, C. Kelsall, G.H. (1993) Photoelectrophoresis of colloidal iron oxides. I. Hematite (a-Fe203). Colloids Surfaces. A. Physics Chemical and Engineering Aspects. 73 145-163... 

Bad appearance. Turbidity is caused by suspended matter, which may contain disease-causing microorganisms. Discoloration that leaves stains can be caused by dissolved or colloidal iron, tannin, or humic acid from decaying vegetation, and excessive salt content. 

If considerably more is added, it will be difficult to observe the red indicator colour of PhjCNa, since the solution will become very dark by the colloidal iron. In the case of smaller amounts of catalyst the conversion into sodamide takes too long. 

It is widely assumed that NO is responsible for the pharmacological effects of nitroglycerin, which has been used to treat angina since 1879. However, this has been challenged by Kleschoyov et al. who, using a colloidal iron-dithiocarbamate preparation to trap the radical in vascular segments, showed that the ability of the compound to induce vasorelaxation is not related to its ability to donate NO.289... 

Pour 2 ml of the prepared colloidal iron hydroxide solution into each of several test tubes and add 2 ml of one of the following solutions of the same normality (0.1 N) to each of them sodium chloride, barium chloride, aluminium chloride, sodium sulphate, aluminium sulphate, or monosubstituted sodium orthophosphate. What do you observe How does the coagulating effect of an electrolyte depend on the sign and magnitude of the charge of its ions ... 

To prepare colloid iron(III) hydroxide, heat 200 mL of distilled water in a beaker to 70°-90°C and leave an identical beaker of water at room temperature. Add 1 mL of 1 M FeCl3 to each beaker and stir. The warm solution turns brown-red in a few seconds, whereas the cold solution remains yellow (Color Plate 31). The yellow color is characteristic of low-molecular-mass Fe3+ compounds. The red color results from colloidal aggregates of Fe3+ ions held together by hydroxide, oxide, and some chloride ions. These particles have a molecular mass of 105 and a diameter of 10 nm, and they contain 103 atoms of Fe. 

An excess of alkene favored the formation of the unsaturated product 44 whereas the silylated compound 45 dominated athigher silane to alkene ratios. The described reaction was also carried out in the presence of colloidal iron and led to results similar to those obtained with Fe(CO)5. Hydrosilylation of vinyltrimethylsilane 46 with chlorosilanes R3SiH using the modified iron carbonyl complex (CH2=CHSiMe3)Fe(CO)4 [44, 45]... 

Waite, T.D. and Morel, F.M.M., 1989a. Photoreductive dissolution of colloidal iron oxide effect of citrate. 3. Colloid Interface Sci., 102 121-137. 

Silt is formed by suspended particulates of all types that accumulate on the membrane surface. Typical sources of silt are organic colloids, iron corrosion products, precipitated iron hydroxide, algae, and fine particulate matter. A good predictor of the likelihood of a particular feed water to produce fouling by silt is the silt density index (SDI) of the feed water. The SDI, an empirical measurement (ASTM Standard D-4189-82,1987), is the time required to filter a fixed volume of... 

Buffle, J., R. R. De Vitre, D. Perret, and G. G. Leppard. 1989. Physico-chemical characteristics of a colloidal iron phosphate species formed at an oxic-anoxic interface of a eutrophic lake. Geochimica et Cosmochimica Acta 53 399-408. 

Dolfing, J., W. J. Chardon, and J. Japenga. 1999. Association between colloidal iron, aluminum, phosphorus, and humic acids. Soil Science 164 171-179. 

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