Nanostructural Engineering of Complex Functional Particles

An NSF Nanoscale Interdisciplinary Research Team (NIRT) Project NSF Grant: EE C-0210835

Project Overview

This goal of this project is to develop synthetic methods and fundamental understanding needed to produce “nanoengineered” particles that could provide unprecedented “intelligent” functionality for a variety of applications. The particle synthesis exploits the self-assembly of soap-like molecules (surfactants) that can occur during evaporation of droplets to introduce intricate and highly controlled porosity and radially graded structure into silica particles (See graphic). This process can provide a great deal of control over nature of porosity and particle structure by the choice of surfactant, synthesis conditions, or the addition of agents that can provide functionality to the pores. In addition, functional modifications can be made to the particles after synthesis. For example, lipid bilayers are being coated on the outside of mesoporous particles. These bilayers can be functionalized with specific molecular recognition sites or trans-membrane proteins. We are also exploring approaches to attach environmentally (pH, temperature) sensitive molecules to pore walls to effectively act as smart valves between the external environment and the particle interior. It is envisioned that cavities positioned within particle interiors could provide a reservoir for sensing or therapeutic agents whose action or delivery is coupled to molecular recognition functionality at the particle surface and is mediated by controlled transport through nanoporous channels. Such “smart” particles could be used to screen interactions of drugs with membrane proteins or to provide controlled delivery of a therapeutic agent based on an external trigger. Similar complex functionality can be envisioned for other catalyst, sensor, optical or magnetic applications. The synthetic strategies will be guided by experimental and computational research devoted to understanding the fundamental issues related to amphiphilic molecule behavior and assembly in evaporating droplets. To accomplish these objectives, a research team has been assembled providing scientific expertise in aerosol science ( Ward), self-assembly, inorganic materials and sol-gel science (Brinker), catalysis and electron microscopy ( Datye), surface engineering and biomedical materials ( Lopez), and molecular modeling and computation ( Van Swol).

Click Here to see examples of nanoengineered particles that have been produced.

Publications

• Control of Molecular Transport Through Stimuli Responsive Ordered Mesoporous Materials," Fu, Q.; Rama Rao, G.V.; Ista, L.K.; Wu, Y.; Andrzejewski, B.; Sklar, L.A.; Ward, T.L.; Lopez, G.P. Advanced Materials (in press).
• "Biomimetic Molecular Assemblies on Glass and Mesoporous Microbeads forBiotechnology," Buranda, T.; Huang, J.; Ramarao, G.V.; Ista, L.K.; Larson, R.S.; Ward, T.L.; Sklar, L.A.; Lopez, G.P. Langmuir 2003, 19, 1654-1663.
• "Monodisperse Mesoporous Silica Microspheres Formed by Evaporation-Induced Self-Assembly of Surfactant Templates in Aerosols," Rama Rao, G.V.; Lopez, G.P.; Bravo, J.; Pham, H.; Datye, A.K.; Xu, H.; Ward, T.L. Adv. Mater.2002, 14, 1301-1304.
• "Monodisperse Mesoporous Microparticles Prepared by Evaporation-Induced Self-Assembly Within Aerosols," Rathod, S.; Rama Rao, G.V.; Andrzejewski, B.; Lopez, G.P.; Ward, T.L.; Brinker, C.J.; Datye, A.K. MRS Proc., 2003 (in press).
• "Synthesis of Smart Mesoporous Materials," Fu, Q.; Rama Rao, G.V.; Ista, L.K.; Xu, H.; Sklar, L.A.; Ward, T.L.; Lopez, G.P. MRS Proc., 2003 (in press).

People

Principal Investigators Prof. Timothy L. Ward Prof. C. Jeffrey Brinker Prof. Gabriel P. Lopez Prof. Abhaya K. Datye Dr. Frank van Swol	Graduate Students Shailendra Rathod Mangesh Bore Xingmao Jiang Chris Crosher Brett Andrzejewski
Post-Doctoral Scientists Dr. G.V.Rama Rao Dr. Hien Pham Dr. Sivakumar Challa Dr. Yi Yang	Undergraduate Students Tim Olson Kyle Fenton