Cation loading

A. P. Robertson and J. O. Leckie, Cation Binding Predictions of Surface Complexation Models Effects of pH, Ionic Strength, Cation Loading, Surface Complex, and Model Fit, J. Colloid Interface Sci. 188, 444 (1997). 

Cation loading was always performed on the acid-washed samples because determination of the extent of cation loading is facilitated by putting the carboxyl groups in the acid form. The conditions utilized for ion exchange can be seen in Table III further details can be found elsewhere ( ). All the samples were exchanged for 24 h,... 

CATION LOADINGS ON RAW, ACID-WASHED AND BACK EXCHANGED PSOC 623 ... 

Robertson A. and Leckie J. O. (1997) Cation binding predictions of surface complexation models effects of pH, ionic strength, cation loading, surface complex, and model fit. J. Colloid Interface Sci. 188, 444-472. 

Figure 7.3 (A) Seasonal variations in drip rate with superimposed short-term hydrological events from a stalactite in Pere-Noel cave in Belgium there is a close relationship between flow rate and periods of high water excess (Genty and Defiandre, 1998). (B) Variations in cation loads, as monitored by electroconductivity, of drip waters in response to seasonal patterns and individual infiltration events for two drips at Ernesto cave (Frisia et al., 2000).

B) Variations in cation loads, as monitored by electroconductivity, of drip waters in response to seasonal patterns and individual infiltration events... 

Alkaline earth metal cation loaded on Ga-Sil(26) prepared by ion-exchange Me(Ex)Ga-... 

The vapor phase synthesis of methacrylic acid from propionic acid and formaldehyde was studied [42]. In particular, the choice of alkali metal cation and loading were evaluated for their effect on the activity and selectivity of silica supported catalysts. Experiments were carried out in 0.5 in. (o.d.) quartz reactors equipped with 0.125 in. thermowells. Alkali metal cations supported on silica are effective base catalysts for the production of methacrylic acid. Silica surfaces exchanged with alkali metal cations are capable of chemisorbing propionic acid yielding surface-bound silyl propionate esters and metal propionate salts. The alkali metal cation influences the temperature at which desorption of the ester occurs (Cs < Na < Li < support). For silica catalysts of equimolar cation loading, activity and selectivity to methacrylic acid show the opposite trend, Cs > K. > Na > Li. Methacrylic acid selectivity reaches a maximum at intermediate cation loadings where interaction of adjacent silyl esters is minimized [42]. 

The process is illustrated in Figure 21 which shows a cation loaded resin placed between... 

Cation load. Since the influent cation load is expressed as ppm equivalents as CaCOs, it is necessary to convert to units consistent with resin manufacturer s capacity data expressed as kdograins (as CaC03) per of resin. Total cation load in this case is 75+ 50+ 25 = 150 ppm. Convert to kgr (150 ppm)(180,000 gal/cycle)/(1000 gr/kgr) (17.1 ppm/g/gal) = 1580 kgr as CaC03 per cycle. 

Formulating Considerations Compatible with most cosmetic raw materials. New materials give compatibility with high-cationic loadings. Must be hydrated in water phase prior to addition to formulation... 

Molinard pointed out that the ions introduced can serve as specific adsorption sites and that this type of modification allows fine-tuning of the PILC substrate for certain gas adsorption applications [18]. By introducing Sr + in Al-PILC, the gas adsorption isotherms at 273 K and 5 x 10 Pa equilibrium pressure showed that the Nj capacity doubled fi-om 0.06 nunol/g on Al-PILC to 0.12 mmol/g on Sr-Al-PILC. The amoimt of cations in the PILC influences the adsorption properties. A higher cation loading results in a lower capacity but a higher N2/O2 selectivity on Ca-Al-PILC, as was proven by adsorption measurements. For the anion exchanged Cl-Al-PILC, more O2 than N2 was adsorbed (0.09 mmol/g and 0.07 mmol/g, respectively) at 273 K and 5x10 Pa. This affinity for O2 should result from a specific interaction with the Cl"-ions. The CO2 capacity decreased in comparison with the unmodified substrate from 0.5 mmol/g on Al-PILC to 0.2 mmol/g on Cl-Al-PILC at 273 K and 0.5 bar. After modification with other anions, Hke F and PO, the same effect was observed. 

The acid/base properties of zeolites can be systematically changed by acting on various factors nature of the exchange cation, cation loading, decationa-tion, dealumination, which have been discussed in the previous section, and introduction of various elements (Ge, B, P, Ga,...) into the crystal framework, the effects of which we will now describe in more detail... 

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