Microgel swelling behavior

Our group has demonstrated that the catalytic properties of immobilized enzymes can be manipulated by the temperature-dependent swelling behavior of the microgel. The hydrolytic activity of adsorbed and native P-D-glucosidase was determined as a function of temperature. Desorption of immobilized enzyme upon... 

It was taken into account that counterions could leave the interior of the microgel for the external solution and that both contributions of electrostatic interaction of a macroion with escaped counterions and of the osmotic pressure of counterions contribute to the swelling law of a microgel. The swelling behavior of a microgel was analyzed as a function of the number v of polymer chains in the microgel. 

Crowther HM, Vincent B. Swelling behavior of pol y-iV- i sopropy I aery I a m i dc microgel particles in alcoholic solutions. Colloid Polym Sci 1998 276 46—51. 

Kaneda, I. and B. Vincent (2004). Swelling behavior of PMMA-g-PEO microgel particles by organic solvents. Journal of Colloid and Interface Science 274(1) 49-54. 

To discuss the swelling/de-swelling behavior of microgel particles in thermodynamic terms, one may write an osmotic balance between the two terms, (i) and (ii) above, as follows [5] ... 

The dependence a(v) could demonstrate nonmonotonic behavior. In a good solvent the swelling ratio a (i.e., the ratio of current size R of the subchain to its size in the 0-solvent) increases with the growth of the number v of subchains in the microgel (see Figure 7). The reason is that for small particles most of the counterions leave the microgel for the outer solution. 

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