Ionic strength on the interaction

Table VIII shows the effect of ionic strength on the interaction between ionics and POE nonionics. In the catlonlc-nonlonic...

The value of pKint in Eq. (14) should depend on ionic strength. The electrostatic term in this equation includes the effect of ionic strength on the interaction between charges, but not the effect on the chemical potential of the isolated dissociating group in its acidic and basic forms, and this effect therefore remains a factor in pK t. 

Tombacz, E. et al.. Effect of pH and ionic strength on the interaction of humic acid with with aluminium oxide. Colloid Polym. Sci., 278, 337, 2000. 

Leprince, F. and Quiquampoix, H. (1995) Extracellular enzyme activity in soil effect of pH and ionic strength on the interaction with montmorillon-ite of two acid phosphatases secreted by the ectomycorrhizal fungus Hebeloma cylindros-porum. European Journal of Soil Science 47, 511-522. 

This force spectroscopy approach has found application ranging from mapping effect of varying ionic strength on the interactions between charged surfaces [230-245], to studying electrostatic forces at crystal surfaces [246,247],... 

The data presented in Figure 4c,d demonstrate the effect of the ionic strength on the interactions between silica and two PLL-,g-PEG-coated Nb206 surfaces with different PEG surface densities. For the lower PEG density, PLL(20)-,g[10.1]-PEG(2) (0.21 PEGnm ), attractive forces were observed at low ionic strength, revealing the... 

Figure 7.3 Effect of ionic strength on the energy of interaction between spherical particles.

Photo-induced electron transfer between [Ru(bpy)3]2+-like centres covalently bound to positively-charged polymers (N-ethylated copolymers of vinylpyridine and [Ru(bpy)2(MVbpy)]2+) and viologens or Fe (III) has been studied using laser flash photolysis techniques. It is found that the backbone affects the rates of excited state quenching, the cage escape yield, and the back electron transfer rate because of both electrostatic and hydrophobic interactions. The effect of ionic strength on the reactions has been studied. Data on the electron transfer reactions of [Ru(bpy)3]2+ bound electrostatically or covalently to polystyrenesulphonate are also presented. 

In the case of PVA a strong interaction occurs between neighbouring charged sites and, consequently, the ionic strength of the medium has a strong influence on pKo 55) (Table 2). Less influence is exerted by the ionic strength when the interactions between neighbouring units are smaller, as, e.g., in the case of poly(4-vinylpyridine)56). 

The ODN adsorption onto cationic microgel poly(N-isopropylacrylamide) particles was reported to be dramatically affected by the salinity of the incubation medium [9] as illustrated in Fig. 6. The observed result was related to (i) the reduction in attractive electrostatic interactions between ODN molecules and the adsorbent and (ii) the drastic effect of ionic strength on the physico-chemical properties of such particles [17, 27]. In fact, the hydrodynamic size, the swelling ability, the electrokinetic properties, and the colloidal stability are dramatically affected by pH, salt concentration, and the medium temperature [27]. 

Similar uncertainties are true for the effect of ionic strength on the stability constants, as described using SIT, and the corresponding interaction coefficients that are determined. A re-interpretation is necessary that considers polynuclear complex formation. 

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