(398ai) Importance of Temperature On the Gel Electrophoresis of a pH-Regulated, Zwitterionic Sphere

Gel electrophoresis has been adopted widely in soft matter science to characterize/separate entities such as DNAs and proteins. Compared with that in aqueous electrophoresis, the mobility of samples in gel electrophoresis is slower and, therefore, easier to be observed. Due to the presence of Joule effect, temperature can be a significant factor in electrophoresis. Because all the physicochemical properties of the dispersion medium and those of the dispersed entities vary with temperature, its influence on the electrophoretic behavior of an entity can be significant. In this study, we consider the electrophoresis of a pH-regulated, zwitterionic spherical particle in a gel medium under various levels of temperature. This type of particle is capable of simulating a wide class of entities including biocolloids such as DNAs, proteins, and microorganisms, and inorganic colloids such as SiO₂ and TiO₂, where dissociation/association reactions occur on their surface and the associated charged conditions depend upon nearby environment. Choosing an SiO₂ particle in a dilute agarose gel as an example, a detailed numerical simulation is conducted to investigate its electrophoretic behavior under various conditions. The parameters examined include temperature, pH, and the bulk salt concentration. To simulate the usual experimental conditions, we assume that the temperature and the solution pH vary from 283 K to 323 K and 5 to 8.5, respectively.