新型聚乙烯醇/聚乙二醇水凝胶热沉性能研究

To study the feasibility and potential of hydrogels for thermal management, a novel polyvinyl alcohol (PVA) /polyethylene glycol (PEG) composite hydrogel heat sink with good mechanics and economy was prepared by freezing-thaw method. The size of the sink is 60 mm×60 mm×2 mm, and self-cooling is realized by water evaporation on the surface. A heat dissipation experiment was carried out with a heat flow of 2 712 W/m², and the heating characteristics, the relationship of the evaporative convection intensity change and the swelling change law were obtained. It was found that the addition of 2.5% PEG reduced the preparation deformation caused by the increase in the number of freezing cycles, with the water content attenuation being decreased by 75.53%, and the chip surface temperature 7.53%. Based on the experimental results, the evaporation heat transfer coefficient was calculated, and the effects of heat flow, thickness, and humidity on evaporative heat dissipation were studied. The swelling rates of the hydrogel with different temperatures and usage conditions (4 h continuous use and 120-day storage at room temperature) were then measured, showing that the hydrogel has a certain short-term reliability in spite of the insignificant sensitive response to temperature.