Ion-exchange silicas

UNUSUAL REGIOSELECTIVITIES OBSERVED IN THE OLIGOMERIZATION OF PROPENE ON NICKEL(II) ION-EXCHANGED SILICA-ALUMINA CATALYSTS... 

Figure 4 Temperature programmed reduction of Ni(II) ion exchanged silica-alumina...

Unusual Regioselectivities Observed in the Oligomerization of Propene on Nickel(II) Ion-exchanged Silica-Alumina Catalysts 226... 

Ca ion-exchanged silica, anticorrosion pigment, 322 Silicone KF351A... 

Another approach has been the use of suitable ion-exchanged silicas . In the presence of electrolytes, these give protection by releasing passivating ions that can interact not only with the matrix but also with the electrolytic species themselves and the snbstrate see Fig. 1. This type of inhibitor is typified by the fact that it is completely insoluble in water and only works on demand - that is, only when invading electrolytic species are present. 

Fig. 1. Schematic of the corrosion inhibition reaction mechanism for ion-exchanged silicas...

The acid and base properties of catalytic activities of ion-exchanged silica-gel were also studied. Table 3.22 shows the acidity of the cation-exchanged silica gel which was evacuated at 373 or 573 The acidities were determined by an indicator method. 

Fig. 4.14 Ratei of elimination reactions of 2-bromobutan (O) and 2,3-dibromobutane (9) over metal-ion exchanged silica gels at 433 K See note for electronegativity of metal ion. )...

Fletcher, T. (1992). Ion-exchanged silicas as alternatives to strontium chromate in coil coating primer. Polymers Paint Colour Journal, March. 

Ion exchange Silica or polymer grafted with anionic groups (—SO3",—C02, etc.) cationic groups (-NH3+,-N(CH3)3+, etc.) Water and ionic salt anionic (phosphates, acetate, borate, formate, carbonates, etc.) cationic (hydronium, pyridinium, ammonium, etc.) Organic and inorganic ions... 

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