Influence of silica nanoparticles on mass transfer in a membrane-based micro-contactor
Influence of silica nanoparticles on mass transfer in a membrane-based micro-contactor
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DOI：
10.1039/c5ra26056f
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发表时间：
2016-01-01
期刊：
影响因子：
3.9
通讯作者：
Bart, Hans-Joerg
中科院分区：
文献类型：
--
作者：
Ashrafmansouri, Seyedeh-Saba;Willersinn, Stefan;Bart, Hans-Joerg
欧洲经委会（EFCE）美联储,化学。采用enng .)甲苯-丙酮-水萃取试验系统，有机相为含0.001 ~ 0.1 vol%疏水二氧化硅纳米颗粒的甲苯基纳米流体。实验在基于膜的微接触器中进行，在有机相和水相的不同体积流速下，从有机相到水相的传质方向。结果表明，在低流速下，纳米颗粒的传质效果更好。使用体积为0.001 %的二氧化硅纳米颗粒，最大传质系数提高了约31%。在纳米颗粒浓度较高和较低的情况下，提取效率较低。纳米颗粒的布朗运动和诱导微对流被认为是在低浓度纳米颗粒下观察到传质增强的原因。此外，由于固体纳米颗粒的存在，纳米颗粒聚集和自由体积的减少可能会在更高的纳米颗粒浓度下恶化传质。
The EFCE (Europ. Fed. Chem. Engng.) extraction test system of toluene-acetone-water was used, where the organic phase was a toluene-based nanofluid containing 0.001 to 0.1 vol% hydrophobic silica nanoparticles. Experiments were performed in a membrane based micro-contactor at various volumetric flow rates of organic and aqueous phases and with a mass transfer direction from the organic to the aqueous phase. The results showed that nanoparticles are more effective on mass transfer at lower flow rates. A maximum enhancement of about 31% in the overall mass transfer coefficient was observed using 0.001 vol% silica nanoparticles. At higher and lower nanoparticle concentrations, smaller extraction efficiencies were observed. Brownian motion of nanoparticles and induced micro-convection is considered to be responsible for observing mass transfer enhancement at low concentrations of nanoparticles. Also, nanoparticle aggregation and reduction in free volume because of the presence of solid nanoparticles is a possibility for deteriorated mass transfer at higher nanoparticle concentrations.