New Functionalized Mesoporous Silicas for Adsorption of Heavy Metal Ions

Kent State University, Kent OH

Investigators

Abstract

CTS- 0086512 "New Functionalized Mesoporous Silicas for Adsorption of Heavy Metal Ions" Mietek Jaroniec Kent State University ABSTRACT This 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.