Effects of high-voltage electric field produced by an improved electrode system on freezing behaviors and selected properties of agarose gel

Abstract

Abstract This work aimed at evaluating the effects of high-voltage electric field (HVEF) produced by an improved electrode system on the freezing behaviors and selected properties of agarose gel. The freezing of the agarose gel was realized by a Peltier cooler coupled with an improved electrode system. The electrode system was integrated with a dielectric spacer having high permittivity to avoid partial discharges. Results showed that HVEF combined with a low freezing rate significantly reduced the supercooling degree, enhanced the average freezing rate in particular the nucleation rate, and higher internal electric field intensity showed a better microstructure with smaller ice crystals in frozen samples. Under the highest applied voltage of 9\u202fkV ( E i n \xa0=\xa01.09\xa0E+05\xa0V/m) tested in this study, a 100% supercooling release was achieved. Maximum reductions of 78.83%, 25.79% and 28.75% were observed for the nucleation time, tempering time and total freezing time, respectively, while the phase transition time was prolonged by 14.86% as compared with the control (p