纳米碳基表面分子印迹吸附剂综述及其吸附机理探讨

A review of nanocarbon-based molecularly imprinted polymer adsorbents and their adsorption mechanisms

  • 摘要: 纳米碳基材料由于具有低密度、高强度、环境友好、结构可控、表面易于修饰等优点,成为了一类非常理想的表面分子印迹基质材料。相应的纳米碳基表面分子印迹聚合物(C-SMIPs)吸附剂,对于实现液相环境体系中的有机小分子污染物的选择性吸附脱除与富集回收取得了令人满意的效果。本综述对该应用背景下近五年来的不同维度C-SMIPs进行了归纳总结。不仅发现C-SMIPs吸附能力的下限更容易受基质材料的影响,其上限则更多地取决于印迹层的构建情况,以多孔纳米炭球和氧化石墨烯为基质的C-SMIPs通常具有较高的吸附容量,其中氧化石墨烯基SMIPs通常具有较高的吸附效率。同时本综述还推断出C-SMIPs对于目标分子吸附的本质是固液界面间的物理性吸附,解决了长时间以来令人困扰的对吸附过程定性的争议。另外,通过本综述的探讨分析,可以为接下来深入研究C-SMIPs的基质筛选、印迹方法、吸附条件选择等提供一些可借鉴的理论和实践经验,从而不断推进C-SMIPs的研发和应用。

     

    Abstract: Nanocarbon materials have become a class of ideal supports for surface molecularly imprinted materials because of their low density, high strength, environment-friendliness, controllable structure and modifiable surface. Thus, nanocarbon-based surface molecularly imprinted polymer adsorbents (C-SMIPs) have achieved satisfactory performance for the removal and enrichment of organic compound pollutants in liquids. This review summarizes C-SMIPs based on various nanocarbon materials for the treatment of ecological environmental pollutants in water during the last five years. The structural characteristics and adsorption features of these C-SMIPs have been comprehensively and systematically analyzed and compared. It is found that the low limit of adsorption capacity is usually decided by the carbon support while the upper limit depends more on the imprinted layer. Specifically, C-SMIPs based on porous carbon nanospheres or graphene oxide usually have large adsorption capacities. It can also be inferred that the essence of C-SMIP adsorption towards target molecules is physical adsorption at the solid-liquid interfaces, the chemical-like adsorption found in the literature is caused by an extremely strong interaction between active sites and the adsorbate by multiple non-covalent bonds like ionic bonds, hydrogen bonds, electrostatic interactions, and van der Waals forces, which settles the long-standing controversy on the nature of adsorption for C-SMIPs. Moreover, analysis and discussion of the literature provide some theoretical and practical evidence for support optimization, imprinting method amelioration, and adsorption parameter selection, which may promote the development and applications of C-SMIPs.

     

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