采用一步化学法制备了石墨微流体,并采用瞬态热线法测试了石墨微流体的有效导热系数,研究了石墨含量、超声处理时间、微波处理时间及基液种类对石墨微流体有效导热系数的影响。结果表明:不同基液中加入石墨后形成的石墨微流体的有效导热系数均显著增大,且石墨含量越高有效导热系数越大;石墨含量为1.0%时,以去离子水、乙二醇以及二甲基硅油为基液的石墨微流体的有效导热系数提高幅度分别为102.09%、93.17%、225.69%;石墨含量、超声处理时间及微波处理时间相同时,以二甲基硅油为基液的石墨微流体的有效导热系数增幅最大,乙二醇次之,去离子水最小;随着超声处理时间和微波处理时间的延长,石墨微流体有效导热系数的增幅显著降低.
Graphite-based microfluids were prepared via the one-step chemical method,and the effective thermal conductivity of the microfluids was measured by means of the transient hot wire method under the conditions of dif-ferent graphite contents,different ultrasonic time,different microwave time and base fluids.The results show that (1 )the addition of graphite in the base fluids greatly improves the effective thermal conductivity of the microfluids;(2)the effective thermal conductivity of microfluids increases with the increase of the graphite content;(3)the ef-fective thermal conductivities of graphite-based microfluids in three base fluids (DI water,ethylene glycol and dim-ethicone)respectively increase by 102.09%,93.17%and 225.69%at the graphite content of 1.0%;(4)at the same graphite content,the same ultrasonic time and microwave time,dimethicone may result in the largest effective thermal conductivity increment while DI water may result in the smallest one;and (5 )with the prolonging of ultra-sonic time and microwave time,the increment of effective thermal conductivity of graphite-based microfluids signifi-cantly reduces.