Effect of Ionic Strength on the Protein Desorption

The effect of ionic strength on the desorption of preadsorbed proteins above the transition temperature (i.e., 40°C) was also discussed and found to be of great interest as reported by Duracher [32]. In fact, the desorption investigated (in the case of an oppositely charged system at a given pH) as a function of salt concentration was found to dramatically increase from 50% to 95% of the desorbed amount. This was attributed to the screening effect of electrolytes which reduces

FIG. 10 Protein desorbed amount (wt %) onto ammo-containing polystyrene core cross-linked poly(NIPAM) shell. Adsorption-desorption conditions: adsorption at a given pH in the phosphate buffer (10 mM) and at 40°C (for 2 h), and desorption by cooling of sample at 20°C. (The hydrophilic thickness layer of DD4 latex is higher than that of DD11) [32].

FIG. 10 Protein desorbed amount (wt %) onto ammo-containing polystyrene core cross-linked poly(NIPAM) shell. Adsorption-desorption conditions: adsorption at a given pH in the phosphate buffer (10 mM) and at 40°C (for 2 h), and desorption by cooling of sample at 20°C. (The hydrophilic thickness layer of DD4 latex is higher than that of DD11) [32].

the attractive electrostatic interactions as shwon in (Fig. 11). As for classical polyelectrolytes, the adsorption and desorption processes were dramatically affected when pH and salinity were modified as a consequence of alteration in the attractive electrostatic interactions. The only neglected point in the case of thermally sensitive poly(NIPAM)-based colloidal particles was the effect of ionic strength on the poly(NIPAM) chain conformation or basically the effect of ionic strength on the gel swelling ability [17].

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