Projects funded in Year 3
The scope of this work involves the continuing development of SNNI as a major research initiative under ONAMI. The Initiative uses proactive strategies to develop nascent nanomaterials and nanomanufacturing approaches that offer a high level of performance without compromising the environment or health. The work merges the principles of green chemistry and nanoscience to produce safer nanomaterials and more efficient nanomanufacturing processes.
In FY 2007, SNNI underwent a formal review of ongoing projects and advertised an internal call for proposals. New tasks selected served to strengthen the current research thrusts outlined above.
Designing benign nanoparticles
The overarching goal of this research thrust is to formulate structure-property relationships for the biological impact of engineered nanoparticles and to apply these relationships to the design of new materials with tailored properties. By studying the potential toxicological effects of nanoparticles before they are incorporated into technologies we can minimize negative consequences of a growing nanotechnology and promote sustainability. Because nanoparticles are key building blocks for applications in chemical/biological sensing, nanoelectronics, quantum computing, and nanophotonics they are likely to be widely distributed throughout the environment. By using a library of structurally and compositionally well-defined nanoparticles in conjunction with biological assays that examine multiple aspects of cellular and organismal health, it will be possible to identify those that cause harm and develop structure-property relationships to feed back into product design.
Research Group lead: Robert Tanguay (OSU)
Faculty PIs: Jim Hutchison (UO), Eric Johnson (UO), Robert Tanguay (OSU), Galya Orr (PNNL), Marvin Warner (PNNL), Mark Lonergan (UO), Scott Reed (PSU), Stacey Harper (OSU), Shiwoo Lee (OSU)
Expanded libraries of precisely engineered nanoparticles
This research group focuses on the design of new routes to nanomaterials using feedback from biological impact studies to reduce their toxicity and proposes to expand the current library of nanoparticles for investigation of biological interactions to; (a) develop a diverse array of functionalized gold nanoparticles with a variety of core sizes; (b) develop precise libraries of compound semiconductor nanoparticles and purification methods; and (c) continue exploration of the use of naturally occurring lipids to control nanoparticle shape and size.
Probe the biological impacts of functionalized nanoparticles
Biological assays have been established to link the physical, chemical, and geometric properties of structurally well-defined functionalized nanoparticles to their function in biological systems. The biological assays give information on nanoparticle movement and tissue accumulation, changes in gene expression in response to nanoparticle interaction with the cellular environment, and subsequent alterations to organismal viability and development. Individual nanoparticles are tracked in real time through live cells to examine the fate of nanoparticles in cultured. The data from these tracking studies will augment the ongoing in vivo and in vitro toxicity screenings.
Computational and analytic tools to support the development of environmentally-benign nanomaterials
There is a paucity of data on nanoparticle characterization and toxicity or a means for disseminating new data. Many government agencies have called for a method to catalog the anticipated accumulation of data on nanoparticles into a relatively easy searchable database. This research group focuses on the development of a collaborative knowledgebase of Nanomaterial-Biological Interactions (NBI) that is systematically linked to related data/knowledgebases. NBI will serve as a repository for annotated data on nanomaterial-biological interactions. Relevant computational, analytic and data mining tools will be integrated and/or developed to extract useful knowledge from diverse datasets on nanomaterial characterization, synthesis methods and nanomaterial-biological interactions defined at multiple levels of biological organizations.
Developing greener nanomanufacturing of engineered nanoparticles
The aim of this effort is to develop methods of manufacturing nanoparticles using a process that is efficient and minimizes waste, while maintaining the properties needed for high-performance applications. The lessons that emerge from the research conducted during the initial SNNI funding cycle are the importance of developing (i) a mechanistic understanding of the reactions developed for use in microscale reactors, (ii) real-time, in situ, as well as ex situ, characterization methods to guide research and production decisions, and (iii) strong integration and project coordination between the chemistry and engineering in order to develop reactors and methods capable of continuous, high-rate production of highly functionalized nanoparticles.
Research Group lead: Vincent Remcho (OSU)
Faculty PIs: Jim Hutchison (UO), Steven Kevan (UO), Chih-hung Chang (OSU), Brian Paul (OSU), Vincent Remcho (OSU), Todd Miller (OSU), Daniel Palo (PNNL), Andrew Berglund (UO)
Mechanistic studies an in situ spectroscopy toward high-rate, continuous flow nanoparticle production in microchannel reactors
The goal of the research group has been to develop continuous flow production of nanoparticles that increases production rate and decreases waste compared to the batch processes. A first example, a > gram/hour production of monodisperse gold particles, has been accomplished. This research aims to build from the exciting results obtained, extending the size range of gold particles that can be synthesized, completing development of in situ probes of nanoparticle growth for microchannel reactions, integrating nanoparticle purification and parallelize production and applying these methods and approaches to the production of other metal nanoparticles.
Microsystem development for metal nanoparticle production
In our initial efforts, we developed a system that significantly reduces processing time and greatly improves product purity through the application of microreaction technology. In addition, we demonstrated the feasibility and scalability of nanofiltration and size exclusion purification to gold nanoparticle products from the microreaction system. Based on the success of our prior SNNI effort and the knowledge gained from it, we will extend this research to explore the key mechanisms affecting nanoparticle production, the synthesis of other types of engineered nanoparticles, and continue towards total process integration. Additionally, we will explore the modification of the micromixers to include micro-emulsion capability. Device parameters such as flow rate, jet rate/frequency, nozzle material, and nozzle geometry will be investigated for their effects on microemulsion properties.
The use of biological ligands to control the shape of nanoparticles
We designed the ISOS (in vitro selection on surfaces) microreactor technology, which provides a platform to perform SELEX (systematic evolution of ligands by exponential enrichment) experiments on any planar surface. Our focus is on the development of specific biological ligands to control nanoparticle shape and biological targeting. This is a revolutionary step marrying biological systems with nanomaterials and will impact several fields.
Interfacing nanoparticles and nanostructures for device applications
Nanomaterials are driving innovation in optical and electronic devices, however, realizing the full potential of nanoscale matter in device technologies requires the integration of the nanoscale building blocks with other components of the device. Nanostructures can also be important precursors in the low-cost and greener manufacture of more traditional microscale devices and to exotic new materials. Thus, developing environmentally-benign assembly methods and identifying approaches to interface nanomaterials with macroscopic structures are being explored to produce greener, high-performance devices and nanostructured materials.
Research Group Lead: Mark Lonergan (UO)
Faculty PIs: Shane Addleman (PNNL), Gregory Rorrer (OSU), Mark Jones (PNNL), Mark Lonergan (UO), Gertrude Rempfer (PSU), David Johnson (UO), Douglas Keszler (OSU), Mas Subramanian (OSU)
Self-assembly of nanoparticle superstructures
Methods to direct formation of 1, 2, and 3D assemblies of metal nanoparticles will be developed based upon biopolymer templating or surface modification reactions. The approach offers greener methods of construction of nanostructured assemblies useful for sensing, nanoelectronic or optical applications.
Development of nanomaterials for photonic devices
Two types of synthetic routes to developing nanomaterials for photonic devices will be employed; (1) development of environmentally-benign, bio-based routes for the green synthesis of nanoscale photonic crystals designed to enhance solar energy conversion of dye-sensitized solar cells and (2) investigate photonic device structures based on synthetic routes of ionically functionalized nanoparticles. The biological impacts studies will examine the ionically functionalized nanoparticles to guide future design of greener materials.
The chemistry of nanostructured matter: low-temperature and solution-based processing of nanostructured inorganic materials
Our work in the initial support period yielded an understanding of the formation of amorphous films, their transformation to the crystalline states and the potential formation of nanostructured products. We plan to extend the technique to more complex oxides and materials beyond oxides and on controlling the doping levels of these materials to separate effects of different nanostructure from effects caused by different carrier concentrations. This will also allow us to develop a mechanistic understanding of the evolution of solution-derived films and the formation of nanostructured solids from nanostructured precursors prepared by using both solution and vapor phase deposition techniques. The new materials produced will be incorporated into devices such as capacitors, diodes, transistors, and ferroelectric memory elements to evaluate their properties.
Projects completed in Years 1 and 2
Synthesis and surface modification of nanoparticles - develop biologically safer nanoparticles while also directing self-assembly reactions and optimizing interactions with devices. Mingdi Yan (PSU)
Direct synthesis methods and ligand exchange methods are used to prepare metal nanoparticles with desired specificity. Given that the first contact between a nanoparticle and a biological system is the outer surface of the nanoparticle, a strong emphasis is being placed on approaches to tailor the composition and structure of the exterior ligand shell in order to design safer nanoparticulate materials and tuning the electronic or optical coupling. Approaches involving synthetic, biological and photo-crosslinkable ligands are explored.
Apply the unique attributes of the microreactors to produce ceramic nanoparticles in the gas phase. Sundar Atre (OSU), Shoichi Kimura (OSU), Goran Jovanovic (OSU), Vinod Narayanan (OSU)
Developing nanoparticles from materials other than gold will be beneficial in creating a variety of nano-scale devices for a plethora of applications. Thus we will expand our research to include production of ceramic nanoparticles, which we will synthesize in parallel microchannel reactors arrays. In particular, we will develop reactor fabrication methods and integrate powder synthesis to a suitable well-characterized processing stage. We will attempt to understand the influence of reaction parameters on nanoparticle synthesis and particle characteristics and define constraints pertinent to the reaction kinetics. Integral to this research, we will focus on two microscale technology areas: development of microscale chemical reactors and separators suitable for the development of microscale based chemical processes and the development of microscale biosensors devices. These will include development of the process and reactor design package based on the coupled transport-reaction modeling of the powder synthesis schemes.
Examine electronic properties of integrated nanoparticle-based materials to determine how the interfaces influence charge transport in these materials. Richard Taylor (UO)
The objective of this task is to understand carrier transport and charge separation phenomena in a wide range of nanoparticle assemblies. Important areas of research included the exploration and understanding of chaotic dynamics in nanoparticle-based materials, the solid-state electrochemistry of nanoparticle- based mixed ionic/electronic conductors, charge transfer at nanoparticle interfaces, and the development of new tools for studying nanoscale transport and charging. The work is done in the context of developing high performance sensors, adaptive materials, photovoltaics and photodetectors.