Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
J Colloid Interface Sci. 2011 Nov 15;363(2):490-6. doi: 10.1016/j.jcis.2011.07.070. Epub 2011 Jul 29.
A viable cost-effective approach employing mixtures of non-ionic surfactants Triton X-114/Triton X-100 (TX-114/TX-100), and subsequent cloud point extraction (CPE), has been utilized to concentrate and recycle inorganic nanoparticles (NPs) in aqueous media. Gold Au- and palladium Pd-NPs have been pre-synthesized in aqueous phases and stabilized by sodium 2-mercaptoethanesulfonate (MES) ligands, then dispersed in aqueous non-ionic surfactant mixtures. Heating the NP-micellar systems induced cloud point phase separations, resulting in concentration of the NPs in lower phases after the transition. For the Au-NPs UV/vis absorption has been used to quantify the recovery and recycle efficiency after five repeated CPE cycles. Transmission electron microscopy (TEM) was used to investigate NP size, shape, and stability. The results showed that NPs are preserved after the recovery processes, but highlight a potential limitation, in that further particle growth can occur in the condensed phases.
采用非离子表面活性剂 Triton X-114/Triton X-100（TX-114/TX-100）混合物，以及随后的浊点萃取（CPE），是一种可行且具有成本效益的方法，可用于浓缩和回收水介质中的无机纳米粒子（NPs）。金 Au 和钯 Pd-NPs 已在水相中预先合成，并由巯基乙磺酸（MES）配体稳定，然后分散在水非离子表面活性剂混合物中。加热 NP-胶束体系会引起浊点相分离，从而在转变后将 NPs 浓缩到较低相中。对于 Au-NPs，已经使用紫外/可见吸收来定量五次重复 CPE 循环后的回收和再循环效率。透射电子显微镜（TEM）用于研究 NP 的大小、形状和稳定性。结果表明，回收过程后 NPs 得以保留，但突出了一个潜在的限制，即凝聚相中可能会发生进一步的颗粒生长。
