Preparation of binary nanofluid with heat transfer additives by particle surface functionalisation
Preparation of binary nanofluid with heat transfer additives by particle surface functionalisation
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DOI：
10.1007/s42247-021-00260-z
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发表时间：
2021-08
影响因子：
3.8
通讯作者：
Umar Aliyu Muhammad;D. Bhattacharyya;J. L. Endrino;S. Fereres
中科院分区：
文献类型：
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作者：
Umar Aliyu Muhammad;D. Bhattacharyya;J. L. Endrino;S. Fereres
目前的二元纳米流体合成方法与传热添加剂缺乏了解的化学纳米颗粒添加剂的基础流体的相互作用，这起着重要的作用，在纳米颗粒表面上的表面活性剂的吸附。因此，这导致几天后纳米流体内形成聚集体，影响胶体悬浮液的稳定性。在这里，提出了一种新开发的合成方法，包括颗粒表面功能化的溴化锂-氧化铝盐为基础的纳米流体。开发的新程序允许用表面活性剂作为第一步（表面官能化）初始制备纳米颗粒，然后分别用分散稳定剂（阿拉伯树胶）制备基液。然后，通过搅拌和超声处理将制备的氧化铝纳米颗粒分散到基础流体中，以产生最终的纳米流体，即溴化锂-水（LiBr-H2O）-氧化铝纳米流体。到目前为止，适当的程序还没有报道的纳米流体合成结合表面活性剂和分散剂和化学的纳米颗粒-表面活性剂-基流体相互作用，这是彻底的研究，在新的方法。同时表征和分析了通过常规和新程序制备的流体。通过使用表面官能化方法，热导率提高了3%，颗粒浓度分布（悬浮液中的颗粒数量）比传统方法更大，为22.7%。它还实现了5%的动态粘度降低。另一方面，在293 K和373 K的温度范围内，获得的流体的Mouromtseff数值在0.7和1.8之间，表明具有较强的传热能力。从所进行的粒度和浓度分布分析中显而易见的是，该过程产生了更稳定的纳米流体，其在流体内具有高的纳米颗粒分布。这允许流体的热性能的高度改进。图形摘要使用两步法合成具有传热添加剂的纳米流体的新过程的图形摘要
Current binary nanofluid synthesis methods with heat transfer additives lack an understanding of the chemistry of the nanoparticle-additive-base fluid interaction, which plays a significant role in the adsorption of the surfactant on the nanoparticle surface. Consequently, this leads to the formation of aggregates within the nanofluid after a couple of days, affecting the stability of the colloidal suspension. Here, a lithium bromide-alumina salt-based nanofluid is proposed following a newly developed synthesis method including particle surface functionalisation. The new procedure developed allows the initial preparation of the nanoparticles with the surfactant as the first step (surface functionalisation) and then the preparation of the base fluid with a dispersion stabilising agent (Gum Arabic) separately. This is then followed by the dispersion of the prepared alumina nanoparticles into the base fluid, by stirring and ultrasonication to produce the final nanofluid, lithium bromide-water (LiBr-H2O)-alumina nanofluid. Until now, proper procedures have not been reported for the nanofluid synthesis combining surfactant and dispersant and the chemistry of nanoparticles-surfactant-base fluid interaction, which was thoroughly investigated in the new approach. The fluid prepared by both the conventional and new procedures was characterised and analysed simultaneously. A thermal conductivity enhancement of 3% was achieved by using the surface functionalisation method, with greater particle concentration distribution (number of particles in suspension) of 22.7% over the conventional procedure. It also achieved a 5% decrease in dynamic viscosity. On the other hand, a Mouromtseff number value between 0.7 and 1.8 was obtained for the fluid at 293 K and 373 K temperature range, indicating a strong heat transfer capability. It was apparent from the particle size and concentration distribution analysis conducted that this procedure produced a more stable nanofluid with a high distribution of nanoparticles within the fluid. This allows high improvement of thermal properties of the fluid.Graphical abstractGraphical abstract of a new procedure for nanofluid synthesis with heat transfer additives using the two-step method