陈凤兰¹，铁生年¹，汪长安^1,2

(1. 青海大学 新能源光伏产业研究中心，青海 西宁 810016；2. 清华大学 材料科学与工程学院，北京 100084)

DIO:10.13732/j.issn.1008-5548.2022.03.010

收稿日期： 2021-12-07， 修回日期：2022-03-11,在线出版时间：2022-04-27。

基金项目：青海省自然科学基金项目,编号：2020-ZJ-909、2021-ZJ-906；材料复合新技术国家重点实验室(武汉理工大学)开放基金项目,编号：2020-KF-1。

第一作者简介：陈凤兰(1997—)，女，硕士研究生，研究方向为相变储能材料。E-mail：qhucfl202097@163.com。

通信作者简介：铁生年(1965—)，男，教授，博士生导师，研究方向为新材料高值化。E-mail：tieshengnian@163.com。

摘要：以Na₂SO₄·10H₂O-Na₂CO₃·10H₂O-NaCl三元相变体系为基液，采用两步法制备氧化石墨烯(GO)芒硝基相变纳米流体(GSPCNs)。结果表明：纳米GO在温度为35℃以上超声分散于芒硝基相变材料中具有较好的分散稳定性；在35～50℃的温度下，GO-GSPCNs的黏度随时间恒定，无触变性；在35℃下，剪切速率大于30 s^-1时，GO-GSPCNs是牛顿型流体，剪切速率小于30 s^-1时呈非牛顿剪切变稀行为，服从宾汉姆(Bingham)流体模型，一致性指数高于0.999。在剪切应力为100 Pa时，GO-GSPCNs黏度随着温度升高而降低。经1 200次固-液循环后，不同体积分数的GO-GSPCNs流变行为在低剪切速率时发生变化，循环后的流体黏度降低，流动阻力减小。

关键词：纳米氧化石墨烯；芒硝基相变纳米流体；流变特性；固-液循环

Abstract：On the basis of Na₂SO₄·10 H₂O-Na₂CO₃·10 H₂O-NaCl ternary phase change system, graphene oxide(GO)mirabilite phase change nanofluids(GSPCNs) was prepared by two-step method. The results show that nano graphene oxide has good dispersion stability when ultrasonically dispersed in the mirabilite phase change materials at the temperature above 35 ℃. At 35～50 ℃, the viscosity of GO-GSPCNs is constant over time and has no thixotropy. At 35 ℃, when the shear rate is more than 30 s^-1, GO-GSPCNs is the Newtonian fluid, its shear rate is less than 30 s^-1, showing non-Newtonian shear thinning behavior obeying the Bingham fluid model, and disposable index is higher than 0.999. When the shear stress is 100 Pa, the viscosity of GO-GSPCNs decreases with increasing of temperature. After 1 200 solid-liquid cycles of GO-GSPCNs with different volume fraction, the rheological behavior changes at low shear rate. The viscosity of GO-GSPCNs decrease after circulation and the flow resistance of GO-GSPCNs decreases.

Keywords：nano graphene oxide; mirabilite phase change nanofluid; rheological property; solid-liquid circulation

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