Templated Synthesis of Nanoscale Hollow Shells with Controlled Porosity

Cuny City College, New York NY

Investigators

Abstract

CBET-0756409 Couzis The overall objective of the project is to develop facile scalable methods for the fabrication of porous hollow silica spheres using vesicles as templates. The pore structure is determined by the incorporation of pore templating entities in the vesicles that prevent the silica from depositing and polymerizing in those locations. The vesicles are templating the structure at two length scales. The first scale determines the diameter of the spheres, which is less than 100 nm and can be tuned by controlling the size of the vesicle. The second length scale determines the porosity of the shell and is less than 5 nm, again tunable via the molecular weight and molecular shape of the pore templating entity. As part of the overall project, the PI will focus on understanding how to control pore density and size, as well as the shell thickness. These are the key parameters that control the mass transfer process through the shell and provide the connectivity between the interior hollow space and the exterior. Intellectual Merit of the Proposed Work: The project is unique because it aims to control structure independently on multiple length scales simultaneously, the hollow sphere size vs. the shell porosity. Tuning both scales provides the ability to control capacity and rate independently. This type of approach will open up new possibilities for nanostructured materials in a range of fields including catalysis, separations, sensing, drug delivery, and energy storage. Broader impacts of the project: The proposed work, will become part of the cadre of projects available to incoming undergraduate students through the recently awarded collaborative REU site between CCNY and NYU and the existing Soft Materials IGERT. For this reason the REU supplemental funding will provide one undergraduate student with a summer research opportunity. This undergraduate student will work closely with the PhD student supported by this grant and will have access to the various workshop activities offered by the existing REU site. This research allows undergraduates students to tackle a problem that goes beyond one's typical undergraduate training, in the sense that it involves concepts from physics, chemistry, and engineering at the macroscopic and at the molecular level. Experience has shown that such projects have a high level of appeal to undergraduate students. Additionally, the project's RET supplemental funding will leverage CCNY's close relationship with local High Schools focused on Math Science & Engineering, to develop a research partnership with a science teacher. As part of this partnership, the teacher will conduct research in the PIs laboratory during the summer as well as during the academic year (this is facilitated by the close proximity of the High School and CCNY) in the area of nanoparticle synthesis. In addition, as part of this partnership, a teaching module focused on the use of nanoparticles, as building blocks for nanostructures, will be developed. The model will be used to demonstrate aspects of colloidal chemistry and nanoscience to high school Chemistry and physics students.