Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616, United States.
Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616, United States.
J Colloid Interface Sci. 2017 Aug 15;500:96-104. doi: 10.1016/j.jcis.2017.03.108. Epub 2017 Apr 4.
Nanofluids comprising nanoparticle suspensions in liquids have significant industrial applications. Prior work performed in our laboratory on the spreading of a nanofluid on a solid substrate has revealed that the structural disjoining pressure gradient caused by the layering of the nanoparticles normal to the confining plane of the film with the wedge profile is a new mechanism for oily soil detachment from the solid substrate. In the present work, we explore the application of this new mechanism for the solid particle detachment using latex particles on glass and a copper-coated wafer substrate using nanofluids. In the experiment, we employed the nanofluids to observe the detachment of the latex particles adhered to the glass substrate. We found that the structural disjoining pressure exerted by the nanoparticles can detach the solid particles on the glass substrate. A video depicting this mechanism is provided. Our results showed that the detachment of the particulate solid particles on the solid substrate was clearly enhanced by the nanofluids, compared to using only pure liquids (such as water). The detachment efficiency was increased with the increase in the nanoparticle volume fraction. Our nanofluids also showed a greater detachment efficiency for the particulate soil removal from the copper-coated wafer substrates compared to that of pure liquids. We found that the detachment efficiency is well correlated with the calculated structural disjoining energy. Our findings in this paper provide new insights for the novel application of the structural disjoining energy mechanism for cleaning hard surfaces.
包含纳米颗粒悬浮液的纳米流体在工业中有重要的应用。我们实验室之前在研究纳米流体在固体基底上的铺展行为时发现，由于楔形薄膜限制了纳米颗粒沿垂直于薄膜平面的方向分层，导致了结构分离压力梯度的产生，这是一种从固体基底上脱除油性污垢的新机制。在本工作中，我们使用纳米流体研究了该新机制在玻璃基底上的乳胶粒子和铜涂层晶片基底上的固体颗粒脱除中的应用。在实验中，我们采用纳米流体观察附着在玻璃基底上的乳胶粒子的脱除情况。结果表明，纳米颗粒产生的结构分离压力可以脱除玻璃基底上的固体颗粒。我们提供了一段描述该机制的视频。结果表明，与仅使用纯水等纯液体相比，纳米流体明显增强了固体颗粒在固体基底上的脱除效率。随着纳米颗粒体积分数的增加，脱除效率也随之增加。与纯液体相比，我们的纳米流体对铜涂层晶片基底上的颗粒污染物的去除也具有更高的脱除效率。我们发现，脱除效率与计算得到的结构分离能密切相关。本文的研究结果为结构分离能机制在硬表面清洁中的新应用提供了新的见解。
