pH对水合Al2O3纳米流体的稳定性和导热性的影响  

Effects of pH on stability and thermal conductivity of Al2O3-H2O nanofluids

作　　者：王先菊[1,2] 朱冬生[1] 李新芳 汪南[1] 李华[1] 文学艺[2] 

机构地区：[1]华南理工大学化工与能源学院传热强化与过程节能教育部重点实验室,广东广州510641 [2]海军兵种指挥学院,广东广州510431

出　　处：《功能材料》2007年第A08期3140-3143,共4页Journal of Functional Materials

基　　金：广东省关键领域重点突破项目（B10-B2060090）：中国博士后基金资助项目（20060400219）

摘　　要：利用两步法制备了Al2O3水合纳米流体，测试了不同pH值下，不同体积分数的～203纳米流体的zeta电位和导热系数，研究pH值对Al2O3．H20纳米流体稳定性和导热性的影响，实验结果表明：对不同体积分数的Al2O3纳米流体，pH存在一个优化值对应zeta电位的绝对值最大，而电位的绝对值越大，纳米颗粒在流体中分散稳定性越好，因此对Al2O3纳米颗粒来说，要得到稳定分散的纳米流体pH值应在8～9之间为最佳；同样随着pH的变化，也存在一个最优值对应于Al2O3纳米流体的导热系数增加到一个最大的值，并且导热系数随纳米粒子体积分数增加而增大。实验结果表明纳米流体的稳定性和导热性与pH有密切的关系，此结论与文献[6]和[13]中的结论一致。In this paper, Al2O3-H2O nanofluids are prepared by two-steps method. By means of measurement of zeta potential and thermal conductivity at different pH values, the effects of pH value on the stability and thermal conductivity of Al2O3-H2O are studied. The experimental results show that： for different volume fraction of Al2O3 nanoparticle there is an optimizing pH value corresponding to the highest magnitude zeta potential, and the higher magnitude zeta potential of nanofluids is, the more dispersion and stability of the nanofluids are, therefore, for Al2O3 nanoparticle, to get more stability suspension the pH value should be adjusted to 8-9. Similarity, there is an optimizing pH value corresponding to the highest enhancement of effective thermal conductivity than based fluid with the process of pH changing, and the effective thermal conductivity also increases with the Al2O3 nanoparticle volume fraction increasing. From experimental results it noted that the stability and thermal conductivity of nanofluids are very relative to the suspension pH condition that is agree with the results in references [6] and [13].

关 键 词：纳米氧化铝 分散稳定 ZETA电位 导热系数 

分 类 号：TK124[动力工程及工程热物理—工程热物理]