This work aims at enhancing the thermal conductivity of base fluids (water and methanol) through successive washing of polymers from the surface of polyvinylpyrollidone (PVP)‐stabilized copper (Cu) nanoparticles. Cu nanofluids were successfully synthesized and characterized using transmission electron microscope and UV–vis spectrophotometer. Thermal conductivity of freshly prepared Cu nanofluid shows ~10% enhancements. The poor enhancement in thermal conductivity is due to the presence of thick polymer coating on the surface of nanoparticles. A new technique has been developed to erode the polymers from the nanoparticle surface by repeated washing and redispersion. After one‐time washing and redispersion, the thermal conductivity of nanofluid has been increased to 0.732 W/mK (~22% enhancements). Greater enhancement (~30.34%) has been achieved after three times continuous washing and redispersion. Finally, the experimental values of thermal conductivity were compared and validated against the existing Maxwell effective model.

中文翻译：

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聚合物洗涤对铜纳米流体导热系数增强的影响

这项工作旨在通过从聚乙烯吡咯烷酮（PVP）稳定化的铜（Cu）纳米颗粒的表面连续冲洗聚合物来提高基础流体（水和甲醇）的导热性。使用透射电子显微镜和紫外可见分光光度计成功地合成并表征了铜纳米流体。新鲜制备的Cu纳米流体的热导率提高了约10％。导热性差的提高是由于在纳米颗粒表面上存在厚的聚合物涂层。已经开发出一种新技术，通过重复洗涤和再分散从纳米颗粒表面侵蚀聚合物。一次性清洗并重新分散后，纳米流体的导热系数已提高至0.732 W / mK（提高了约22％）。增强效果更好（〜30。连续清洗和再分散三遍后，已达到34％）。最后，对导热系数的实验值进行了比较，并针对现有的麦克斯韦有效模型进行了验证。