Yttrium basic carbonate

IV. Yttrium basic carbonate and oxide on hematite. J. Coll. Interf Sd. 126 645-649 Ainsworth, C.C. Sumner, M.E. (1985) Effect of aluminum substitution in goethite on phosphorus adsorption II. Rate of adsorption. Soil Sd. Soc. Am. J. 49 1149-1153... 

One important aspect of such coating processes is the generality of the procedure. It would appear that specific surface characteristics of the preformed particles are not necessarily essential for the successful deposition of the new layer. For example, yttrium basic carbonate coatings were produced on zirconium basic sulfate... 

Using the same procedure, spherical nanosize particles of hematite were coated with yttrium basic carbonate and showed that various surface thermodynamic properties of these systems were essentially those of yttria (37). 

Thermal Decomposition of Latex Coated with Yttrium Basic Carbonate at 800°C... 

Aiken B, Matijevic E (1988) Preparation and properties of uniform coated inorganic colloidal particles, 4. Yttrium basic carbonate and yttrium-oxide on hematite. J Colloid Interface Sci 126 645-649... 

Figure 2.28 Transmission electron micrograph of yttrium basic carbonate (YOHCO3) particles coated with Si02 showing (a) smooth Si02 coating when the reaction was carried out at room temperature and (b) rough Si02 coating formed at higher reaction temperature (SOT). (From Ref. 86.)...

In most cases the coating alone may be changed on subsequent treatments (e.g., by calcination at elevated temperatures), such as by converting basic carbonates into oxides. However, in some instances the shell and the core may interact to yield a different compound. For example, silica particles coated with Y(0H)C03 on heating to IOOO°C reacted to yield yttrium silicate, Y2Si207, which was restricted to the shell, as long as the amount of silica in the core was in molar excess (32). 

Basic yttrium carbonate [Y(OH)COs] was deposited by CD and snbseqnently annealed in air at 600°C to Y2O3 [51 ]. Si wafers and self-assembled monolayers with sulphonate endgronps were used as substrates. An aqneons solntion of YNO3 and urea was heated at 80°C in sealed vials. The increase in pH, together with generation of carbonate from hydrolysis of urea (Sec. 3.2.4.1), resulted in formation of the basic carbonate. 

The application of mechanical activation for the synthesis of the mentioned above compounds started with the activation of the mixtures of anhydrous oxides [15]. Then, barium oxide (or carbonate) in the mixture was replaced with barium nitrate [16], while copper oxide was replaced with copper hydroxide or basic carbonate Cu2C03(0H)2 [17]. Later, yttrium and copper nitrates were used instead of oxides, while barium hydroxide Ba(OH)2 or Ba02 were used as barium-containing compound [18] finally, the mixture of oxides was activated in the presence of water added for the purpose of obtaining well-molding pastes [19]. After activation, the mixtures were annealed at increased temperature, but the synthesis... 

Sprycha, R., Jablonski, J., and Matijevic, E., Zeta potential and surface charge of monodispersed colloidal yttrium(in) oxide and basic carbonate, 7. Colloid Interf. Sci., 149, 561, 1992. 

Yttrium ions are weakly hydrolyzed in water to Y0H(H20)n. The resulting release of hydronium ions accelerates urea decomposition according to Eq. (2.44). The overall reaction for the precipitation of the basic carbonate can, therefore, be written as... 

T. Curtius and A. Darapsky prepared a basic salt, lanthanum hydroxyazide, La(0H)(N3)2l H20, by boiling a soln. of lanthanum nitrate and sodium azide. The white, slimy mass of basic lanthanum azide is obtained by evaporating the mixed soln. in vacuo, or by treatment of the soln. with a mixture of alcohol and ether. They also made rose-coloured didymium hydroxyazide, Dy(OH)(N3)2, by evaporating a soln. of didymium carbonate in hydrazoic acid. Freshly precipitated yttrium hydroxide dissolves in hydrazoic acid, forming a soluble yttrium hydroxyazide boiling a soln. of yttrium sulphate and sodium azide gives a precipitate of yttrium hydroxide. L. M. Dennis found that zirconium hydroxide is precipitated when a soln. of zirconium salt is treated with potassium azide. 

The basic elements of a SOFC are (1) a cathode, typically a rare earth transition metal perovskite oxide, where oxygen from air is reduced to oxide ions, which then migrate through a solid electrolyte (2) into the anode, (3) where they combine electrochemically with to produce water if hydrogen is the fuel or water and carbon dioxide if methane is used. Carbon monoxide may also be used as a fuel. The solid electrolyte is typically a yttrium or calcium stabilized zirconia fast oxide ion conductor. However, in order to achieve acceptable anion mobility, the cell must be operated at about 1000 °C. This requirement is the main drawback to SOFCs. The standard anode is a Nickel-Zirconia cermet. 

Oxides of the type RjO arc formed by all rare earth elements, by the ignition of the hydroxide, nitrate, sulfate, carbonate, or oxalate. In general the basicity decreases with increase of atomic weight, though yttrium and scandium are exceptions to the rule. The basicity of lanthanum approaches that of the alkaline earths, while scandium is about as basic as aluminium. 

Recycling of yttrium is carried out in only small quantities, primarily from laser crystals and synthetic garnets (Hedrick 2002), but extraction may also be possible from used red phosphor or from South African fly ash and FeCr dusts (Deuber and Heim 1991). Basic yttrium carbonate is useful for the elimination of arsenite and arsenate ions from polluted water, including the recycling of yttrium (Wasay et al. 1996). 

Waysay S. a., Haron M. D. J., UcmuMi A. and Tokunaga S. (1996) Removal of arsenite and arsenate ions from aqueous solution by basic yttrium carbonate. Water Res. 30, 1143-1148. 

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