School of Chemistry, The University of Melbourne, VIC 3010, Australia; Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India.
School of Chemistry, The University of Melbourne, VIC 3010, Australia.
Waste Manag. 2021 Apr 1;124:54-62. doi: 10.1016/j.wasman.2021.01.009. Epub 2021 Feb 15.
A cross-linked polymer inclusion membrane (CL-PIM) incorporating the extractant trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate (Cyphos® IL 104) was developed for the first time for the enhanced Au(III) recovery from aqua regia digests of electronic waste (discarded mobile phones). Cellulose triacetate (CTA), poly(vinyl chloride) (PVC) and poly(vinylidene fluoride-co-hexafluropropylene) (PVDF-HFP) were examined as base polymers. The suitability of poly(ethylene glycol) dimethylacrylate (PEGDMA), poly(ethylene glycol) divinyl ether (PEGDVE) and N-ethylmaleimide (NEM) as cross-linking agents, and the possibility of using triarylsulfonium hexafluorophosphate (TASHFP) and 2,2-dimethoxy-2-phenylacetophenone (DMPA) as initiators were investigated. It was demonstrated that the CL-PIMs composed of Cyphos® IL 104 (30 wt%), PVDF-HFP, PEGDMA (base polymer to cross-linking agent ratio 6:4) and DMPA (1 wt%) or TASHFP (2 wt%) transported Au(III) from 2.5 mol L hydrochloric acid solutions twice as fast as their non-CL-PIM counterpart, showing excellent stability over five successive transport experiments. However, in aqua regia feed solutions (6 mol L acidity) only the CL-PIM containing TASHFP was able to achieve complete Au(III) recovery. AFM studies revealed that the PVDF-HFP-based CL-PIMs had a much higher surface contact area when compared to their non-CL counterpart, and this is proposed to be the reason for their superior transport performance. The CL-PIM that showed good transport efficiency in aqua regia was also applied to aqua regia digests of electronic waste from two mobile phones, and Au(III) was selectively recovered in less than 24 h, while other metals present in significantly higher concentrations were not transported.
首次开发了一种用于从电子废物（废弃手机）的王水消解物中增强 Au(III) 回收的交联聚合物包埋膜（CL-PIM），其中包含萃取剂三己基十四烷基膦双（2,4,4-三甲基戊基）膦酸盐（Cyphos® IL 104）。考察了纤维素三醋酸酯（CTA）、聚氯乙烯（PVC）和聚偏二氟乙烯-六氟丙烯（PVDF-HFP）作为基础聚合物。研究了聚乙二醇二甲基丙烯酸酯（PEGDMA）、聚乙二醇二乙烯基醚（PEGDVE）和 N-乙基马来酰亚胺（NEM）作为交联剂的适用性，以及三芳基硫鎓六氟磷酸盐（TASHFP）和 2,2-二甲氧基-2-苯乙酮（DMPA）作为引发剂的可能性。结果表明，由 Cyphos® IL 104（30wt%）、PVDF-HFP、PEGDMA（基础聚合物与交联剂的比例为 6:4）和 DMPA（1wt%）或 TASHFP（2wt%）组成的 CL-PIM 从 2.5mol L 盐酸溶液中两次输送 Au(III)的速度是其非 CL-PIM 对应物的两倍，在五次连续输送实验中表现出优异的稳定性。然而，在王水进料溶液（6mol L 酸度）中，只有含有 TASHFP 的 CL-PIM 能够实现完全回收 Au(III)。AFM 研究表明，与非 CL-PIM 相比，PVDF-HFP 基 CL-PIM 具有更高的表面接触面积，这被认为是其优异输送性能的原因。在王水中表现出良好输送效率的 CL-PIM 也应用于来自两部手机的王水消解物电子废物，Au(III) 在不到 24 小时内被选择性回收，而存在浓度明显更高的其他金属则未被输送。
