论文部分内容阅读
一个唯象的朗道·德文希尔理论被用来研究外部应力对P(VDF-TrFE)聚合物电热效应的影响。P(VDF-TrFE)(55/45)体材料和P(VDF-TrFE)(70/30)薄膜材料的电热效应极大地依赖于外部应力。外部应力和失配应变并不改变电热系数的最大值,但会减小电热系数最大值所对应的温度。对于P(VDF-TrFE)(55/45)体材料,张应力减小绝热温度改变值,并且最大的室温绝热温度改变发生在应力为180兆帕时。对于P(VDF-TrFE)(70/30)薄膜,张应力或压失配应变减小其绝热温度改变。而且,张应力和压应变同时作用可以导致大的室温绝热温度改变,这能为实际的制冷应用提供潜在的应用前景。
A phenomenal Landau Devonshire theory was used to study the effect of external stress on the electrothermal effect of P (VDF-TrFE) polymers. The electrothermal effect of P (VDF-TrFE) (55/45) bulk material and P (VDF-TrFE) (70/30) thin film material strongly depends on external stress. External stress and mismatch strain do not change the maximum value of the coefficient of electric heating, but reduce the temperature corresponding to the maximum value of the coefficient of electric heating. For P (VDF-TrFE) (55/45) bulk materials, the tensile stress decreases the change in adiabatic temperature, and the largest change in room temperature adiabatic temperature occurs at a stress of 180 MPa. For P (VDF-TrFE) (70/30) films, the tensile stress or the mismatch strain decreases and the adiabatic temperature changes. Moreover, the simultaneous application of tensile stress and compressive strain can lead to large room temperature adiabatic temperature change, which can provide potential application prospects for practical refrigeration applications.