New Functionalized Mesoporous Silicas for Adsorption of Heavy Metal Ions

“用于吸附重金属离子的新型功能化介孔二氧化硅”Mietek JaroniecKent州立大学摘要该研究项目的重点是开发具有高负载能力的重金属离子吸附剂，这种吸附剂可以很容易地再生和重复使用，而不会造成任何明显的负载能力损失。更具体地说，我们的努力是合成新的介孔硅基吸附剂，用于从水溶液中去除汞离子和其他重金属离子。多孔二氧化硅表面被配体功能化，如1-苯甲酰-3-[3-（三乙氧基硅基）丙基]硫脲和1-烯丙基-3-[3-（三乙氧基硅基）丙基]硫脲，它们对汞和其他重金属离子的结合强度低于常用的3-巯基丙基配体。因此，应该有可能在较温和的条件下（即不使用浓酸）再生这些新的吸附剂，从而防止再生时吸附能力的损失。这些吸附剂是通过自组装二氧化硅/表面活性剂介孔结构材料的直接功能化和具有高比表面积、大孔体积和易于接近的多孔结构的无表面活性剂介孔二氧化硅的功能化制备的。对所得到的重金属离子吸附剂的性能进行了严格的评估，并寻求了水处理中载体、功能化过程和配体的最佳组合。所提出的研究的直接影响将是新的、易于再生的吸附剂的可用性，用于选择性吸附水中有害的重金属离子。这项研究有望为一些重要但尚未解决的问题提供有价值的见解，这些问题是受限制的几何形状和孔径对离子和分子物种吸附的影响，并揭示了键合层的结构和类型与其在金属离子吸附中的性能之间的潜在有用的相关性。拟议研究的跨学科性质为培养研究生和本科生在学术界和工业界的一系列职业提供了独特的教育机会。此外，学生将有很好的机会参与PI在纳米结构材料的合成，功能化和应用领域建立的国际合作。

CTS- 0086512"New Functionalized Mesoporous Silicas for Adsorption of Heavy Metal Ions"Mietek JaroniecKent State UniversityABSTRACTThis research project is focused on the development of heavy-metal-ion adsorbents that would exhibit high loading capacities and could be readily regenerated and reused without any appreciable loss of the loading capacity. More specifically, the effort is to synthesize new mesoporous silica-based adsorbents for removal of mercury ions and other heavy-metal ions from aqueous solution. The porous silica surface is being functionalized with ligands such as 1-benzoyl-3-[3-(triethoxysilyl)propyl]thiourea and 1-allyl-3-[3-(triethoxysilyl)- propyl] thiourea, which are expected to bind mercury and other heavy metal ions less strongly than in the case of commonly used 3-mercaptopropyl ligands. Thus, it should be possible to regenerate these new adsorbents under milder conditions (i.e., without using concentrated acids), and consequently, to prevent the loss of adsorption capacity upon regeneration. These adsorbents are being prepared by a direct functionalization of self-assembled silica/surfactant mesostructured materials and by functionalization of surfactant-free mesoporous silicas of high specific surface areas, large pore volumes, and readily accessible porous structures. The performance of the resulting heavy-metal- ion adsorbents are critically evaluated, and the best combination of support, functionalization procedure, and ligand for water treatment is being sought. The immediate impact of the proposed research will be the availability of novel, easy-to- regenerate adsorbents for selective adsorption of harmful heavy-metal ions from waters. This study promises to provide valuable insight into important and yet largely unresolved problems of the influence of confined geometry and pore size on adsorption of ionic and molecular species and to reveal a potentially useful correlation between the structure and type of bonded layers with their performance in metal-ion adsorption. The interdisciplinary nature of the proposed research provides a unique educational opportunity for training graduate and undergraduate students for a range of careers in academia and industry. Also, students will have an excellent opportunity to participate in the international collaborations established by PI in the area of synthesis, functionalization, and application of nanostructured materials.