Retention mechanisms of 1.7 nm ZnS quantum dots and sub-20 nm Au nanoparticles in ultrafiltration membranes
Retention mechanisms of 1.7 nm ZnS quantum dots and sub-20 nm Au nanoparticles in ultrafiltration membranes
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1.7nm ZnS量子点和亚20nm Au纳米粒子在超滤膜中的保留机制
DOI：
10.1016/j.memsci.2018.09.033
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发表时间：
2018
影响因子：
9.5
通讯作者：
D. Pui
中科院分区：
文献类型：
--
作者：
Handol Lee;D. Segets;S. Süß;W. Peukert;Sheng;D. Pui
膜法被认为是一种非常有效和有前途的饮用水和废水处理方法。然而，由于胶体与膜之间复杂的表面相互作用，颗粒去除机理尚未完全阐明，特别是对于非常小的胶体颗粒。在这项研究中，对八种不同类型的膜过滤器进行了一系列系统的过滤试验，这些过滤器的标称孔径从0.005到0.1 µm，与1.7 nm的硫化锌量子点(QD)和5，10和20 nm的Au纳米颗粒(NPs)进行了一系列的过滤试验，以了解它们的截留机理，包括滤膜表面前面的截留和滤膜内部的吸附。通过比较截留率、吸附和回收率，发现不同的过滤器保留小颗粒的主要保留机制是不同的。例如，静电斥力对NPs的排斥起着重要作用，即阻止它们进入大多数膜的膜孔。相比之下，由于静电吸引，尼龙膜对Au NPs具有显著的吸附保留能力。此外，还发现过滤流量或通量也是最终截留的重要参数，因为增强的流体动力阻力可以触发沉积的纳米颗粒的脱离或通过表面入口挤压纳米颗粒而导致穿透。用五种不同的膜对10 nm Au-NP进行了截留试验，结果表明，不同膜的截留效率差异很大，说明孔径大小不应作为评价过滤器性能的唯一标准，尤其是对于小的NPs。我们的结果不仅对各种膜的滞留机理提供了详细的见解，而且还为如何为不同的过滤目的选择膜过滤器提供了建议。
Membrane processes are considered to be a very effective and promising method for drinking water and wastewater treatments. However, particle removal mechanisms have not been fully elucidated due to complex surface interactions between colloids and membranes, especially for very small colloidal particles. In this study, a series of systematic filtration tests for eight different types of membrane filters, having nominal pore sizes from 0.005 to 0.1 µm, against 1.7 nm ZnS quantum dots (QDs) and 5, 10 and 20 nm Au nanoparticles (NPs) was performed to understand their retention mechanisms, including rejection in front of the filter surface and adsorption inside the filter. By comparing rejection, adsorption and recovery, it was found that the predominant retention mechanisms for retaining small NPs varied from filter to filter. For instance, electrostatic repulsion played a significant role for the rejection of NPs, i.e. impeding them entering the membrane pores in most membranes. In comparison, the Nylon membrane had a significant adsorption retention ability for Au NPs due to electrostatic attraction. Besides, it was found that filtration flow rate, or flux, was also an important parameter for the final retention because the enhanced hydrodynamic drag could trigger the detachment of deposited NPs or press NPs flowing through the superficial entrance leading to penetration. Tests of 10 nm Au NP retention using five different membranes with the same nominal pore size of 0.1 µm showed large variation of NP retention efficiencies demonstrating that pore size should not be used as the only criterion for rating filter performance, especially for small NPs. Our results provide not only detailed insights into the retention mechanisms of various membranes but also suggestions on how to select membrane filters for different filtration purposes.
影响因子：
17.1
作者：
Gaborski TR;Snyder JL;Striemer CC;Fang DZ;Hoffman M;Fauchet PM;McGrath JL
通讯作者：
McGrath JL
DOI：
10.2217/nnm.11.78
发表时间：
2011-07
期刊：
Nanomedicine (London, England)
影响因子：
--
作者：
Stensberg MC;Wei Q;McLamore ES;Porterfield DM;Wei A;Sepúlveda MS
通讯作者：
Sepúlveda MS