Membrane Science & Technology Cluster, MESA+ Institute for Nanotechnology, University of Twente, Faculty of Science and Technology, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
Membrane Science & Technology Cluster, MESA+ Institute for Nanotechnology, University of Twente, Faculty of Science and Technology, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
J Colloid Interface Sci. 2017 Nov 15;506:308-318. doi: 10.1016/j.jcis.2017.07.043. Epub 2017 Jul 15.
The increasing use of engineered nanoparticles in customer products results in their accumulation in water sources. In this experimental study, we investigated the role of surfactant type (cationic, anionic and non-ionic) and concentration on fouling development, nanoparticle rejection and fouling irreversibility during dead-end ultrafiltration of model silica nanoparticles. Our work demonstrates that the type of surfactant influences the nanoparticle stability, which in turn is responsible for differences in fouling behavior of the nanoparticles. Moreover, the surfactant itself interacts with the PES-PVP membrane and contributes to the fouling as well. We have shown that anionic SDS (sodium dodecylsulfate) does not interact extensively with the negatively charged silica nanoparticles and does not change significantly the surface charge and size of these nanoparticles. Adsorption of the cationic CTAB (cetyltrimethylammonium bromide) onto the silica nanoparticles causes charge transition and nanoparticle aggregation, whereas non-ionic TX-100 (Triton X-100) neutralizes the surface charge of the nanoparticles but does not change significantly the nanoparticle size. The most severe fouling development was observed for the silica nanoparticle - TX-100 system, where nanoparticles in the filtration cake formed exhibited the lowest repulsive interactions. Rejection of the nanoparticles was also highest for the mixture containing silica nanoparticles and TX-100.
随着工程纳米粒子在消费品中的应用越来越多，它们在水源中的积累也越来越多。在这项实验研究中，我们研究了表面活性剂类型（阳离子、阴离子和非离子）和浓度对模型二氧化硅纳米粒子死端超滤过程中污垢形成、纳米粒子截留和污垢不可逆性的影响。我们的工作表明，表面活性剂的类型影响纳米粒子的稳定性，这反过来又导致纳米粒子污垢行为的差异。此外，表面活性剂本身与 PES-PVP 膜相互作用，并导致污垢的形成。我们已经表明，阴离子 SDS（十二烷基硫酸钠）与带负电荷的二氧化硅纳米粒子不会广泛相互作用，也不会显著改变这些纳米粒子的表面电荷和粒径。阳离子 CTAB（十六烷基三甲基溴化铵）吸附到二氧化硅纳米粒子上会导致电荷转移和纳米粒子聚集，而非离子 TX-100（曲拉通 X-100）则中和纳米粒子的表面电荷，但不会显著改变纳米粒子的粒径。在二氧化硅纳米粒子-TX-100 体系中观察到最严重的污垢形成，其中过滤饼中形成的纳米粒子表现出最低的排斥相互作用。对于含有二氧化硅纳米粒子和 TX-100 的混合物，纳米粒子的截留率也最高。
