Precipitates properties

In periphery-functionalized dendritic catalysts, the functional groups at the surface determine the solubility and miscibility and thus the precipitation properties. Many dendrimers functionalized with organometallic complexes do not dissolve in apolar solvents, and the presence of multiple metal centers at the periphery facilitates precipitation upon addition of this type of solvent. It is emphasized that the use of dendrimer-immobilized catalysts with the goal of recovery through precipitation is worthwhile only if the tendency to precipitation of the dendritic system exceeds that of its non-dendritic equivalent. 

Wu S, Bras RL, Barros AP (2006) Sensitivity of channel profiles to precipitation properties in mountain ranges. J Geophys Res 111, doi 10.1029/2204JF000164... 

As outlined above, nucleation rates are extremely sensitive to temperature changes. Therefore, precipitation temperature is a decisive factor in controlling precipitate properties such as primary crystallite sizes, surface areas, and even the phases formed. However, it is very difficult to state how the precipitation temperature has to be adjusted to achieve a product with specific properties. The optimum precipitation temperature usually is a parameter which has to be determined experimentally. 

In general, it is very difficult to measure directly the activity or concentration of reactive species independently one from another. Unless a sufficiently sensitive, quick dynamic response, species-specific probe-electrode can be applied for each of the reactants, the direct measurement of such a fundamental precipitation property as momentary supersaturation is rarely possible. Therefore, often the ratio of concentration of one of the reagents whose concentration can be monitored independently, to its solubility, is used as a measure of supersaturation. As a further simplification, a ratio between the concentration of the influx reagent stream and the solubility, i.e., an initial supersaturation ratio, can be used to characterize supersaturation at the onset of nucleation, Tanaka and Iwasaki (1985). 

From eq. [21.3.1] it is clear that molecular oxide concentration in the saturated solution is not dependent on the constituent ion concentrations but connected with the precipitate properties, mainly with the molar surfaee of the deposit, a. 

This procedure makes use of the co-precipitation properties of the different oxidation states of Pu on BiPO. The Pu is first oxidized to Pu(VI) which does not carry on BiPO, and then reduced to Pu(IV) which carries. An additional purification step is provided by extraction into TTA. Yield is greater than 60%. 

Polyelectrolyte and non-polyelectrolyte acrylamide random copolymers and graft copolymers of dextran with acrylamide were synthesized to evaluate the effects of polymer composition and structure on viscosity modification and solution behavior in water and brine. Polymer solution rheological behavior and precipitation properties were measured. 

Zinc/cobalt electroplating baths started in Germany in 1985. For zinc/ nickel baths, a new type— Zin-Loy—was introduced with improved precipitation properties. The corrosion protection in accelerated tests was summarized by Siegert and Hadley (1989), who used German national standards (DIN). 

Alloying element edacity Plateau pressure Cycle life Rate capability Initial activation Decrepitation Precipitate property formation ... 

The same group published another contribution to this topic which describes the complexation of oppositely charged PEs, focusing on the effect of ion pair formation [98]. The free energy was derived from the law of mass action, where the Flory-Huggins parameter was influenced by the polymer fraction [98]. The PE cluster structure, as well as the precipitate properties were described to be salt dependent, which is also in agreement with other theories [16, 98]. 

To improve precipitation properties of MPEG when the synthesized oligosaccharide extends beyond five monosaccharides and its protected form approaches m.w. 5,000, a suitable remedy is to use MPEG of average mw = 12,000 [43]. Also, shorter MPEG of average mw = 2,000 was used in some cases, and instead of the precipitation a filtration through a silica gel column was used for purification [44]. 

From Eq. [9.2.124] it is clear that the concentration of non-dissociated oxide in the saturated solution does not depend on the concentration of constituent ion but it depends on precipitate properties, mainly on the molar surface of the deposit, a. Since concentration of the non-dissociated oxide in the saturated solution is rarely determined, the magnitudes of (used below pK eo -logBC ure usually employed for description of the saturated solutions. The known values of und K eo Permit estimation of the concentration of non-dissociated oxide, s eo iu the saturated solution ... 

Uses Corrosion inhibitor dispersant for controlling silica and magnesium silicate precipitation Properties Liq. 

---