State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, Beijing 102249, PR China.
Chemosphere. 2018 Sep;207:489-496. doi: 10.1016/j.chemosphere.2018.05.054. Epub 2018 May 12.
Two novel biphenyl and dipyridyl gemini surfactants, bis-N, N, N,-hexadecyldimethyl-p-biphenylenediammonium dichloride (BHBP) and 1,1'-dihexadecyl-4,4'-bispyridinium bromide (DHBP) were designed and used to functionalize the high layer charged vermiculite (Vt) for the first time. Key organo-Vt characteristics, such as the modifier loading, arrangement and the stacking unit of platelets were specified by FT-IR, XRD, TG, SEM and Elemental Analysis. The saturated surfactant dosage in the modification process, in reverse relationship with the availability of the modifier, was defined as low as 0.4 CEC of Vt. The adsorption performance of organo-Vts were tested by bisphenol A (BPA), which showed great potential as organic adsorbents (143.5 mg g and 139.7 mg g for BHBP-Vt and DHBP-Vt, respectively). Insights into the adsorption mechanism were discussed through kinetics, isotherms and thermodynamics, as well as characterization of the spent samples. BPA onto orgno-Vts matched well with pseudo-second-order, Freundlich models and an exothermic process in nature. Interestingly, π-π interactions between aromatic rings were stronger than that between heteroaromatic ring and aromatic ring, and π-π stacking between the BPA adsorbed and dissociated in solution turned out to promote the adsorption process. The organo-Vts were sustainable and could reuse by ethanol at least for three cycles. Organo-Vts could not only guide focuses on the high layer charged precursors, but open up a new area for the fabrication of novel materials to serve as tunable and cost-effective adsorbents.
两种新型联苯和联吡啶双子表面活性剂，双-N，N，N-十六烷基二甲-p-联苯二铵二盐酸盐（BHBP）和 1,1'-二十六烷基-4,4'-联吡啶溴化物（DHBP）首次被设计并用于功能化高层荷电蛭石（Vt）。关键的有机 Vt 特性，如改性剂的负载、排列和板层的堆叠单元，通过 FT-IR、XRD、TG、SEM 和元素分析来确定。改性过程中表面活性剂的饱和用量与改性剂的有效性成反比，低至 Vt 的 0.4 CEC。通过双酚 A（BPA）测试了有机 Vt 的吸附性能，作为有机吸附剂具有很大的潜力（BHBP-Vt 和 DHBP-Vt 分别为 143.5 mg/g 和 139.7 mg/g）。通过动力学、等温线和热力学以及对用过的样品进行表征，探讨了吸附机制。BPA 与 orgno-Vt 的吸附符合准二级、Freundlich 模型和自然的放热过程。有趣的是，芳环之间的π-π相互作用强于杂芳环与芳环之间的相互作用，吸附和解吸在溶液中形成的 BPA 之间的π-π堆积促进了吸附过程。有机 Vt 是可持续的，至少可以通过乙醇重复使用三到五次。有机 Vt 不仅可以引导人们关注高层荷电前体，而且为制造新型材料开辟了一个新的领域，这些材料可以作为可调谐和具有成本效益的吸附剂。
