Projects in 2008

The scope of the work involves the establishment of a research collaborative, SNNI, within the Oregon Nanoscience and Microtechnologies Institute (ONAMI). The Initiative develops new nanomaterials and nanomanufacturing approaches that offer high performance, yet minimal risk to health or the environment. This inaugural year merged the principles of green chemistry and nanoscience to produce inherently safer nanomaterials and more efficient nanomanufacturing processes in the context of producing nanoparticle and nanostructured materials applications in photovoltaics, nanoelectronics and sensing. The three research thrusts are:

Designing Greener nanomaterials

We develop methods to prepare libraries of functionalized metal nanoparticles in which the size, shape and functionality can be widely varied. We will study the accumulation of nanoparticles within organisms and the impacts of these nanoparticles on viability, gene expression and development. These data are used to guide the development of more benign nanoparticles for a wide range of applications. The surface of these nanoparticles are modified which will direct self-assembly, tune electronic or optical coupling, and further enhance the biologically safety of these nanoparticles.

Karen Guillemin (UO), John Postlethwait (UO), Eric Johnson (UO), Scott Reed (PSU), Andrew Berglund (UO), Kenneth Doxsee (UO), Jim Hutchison (UO), Mingdi Yan (PSU)

Study the biological implications of well-defined functionalized gold nanoparticles in two model organisms

Researchers are working to determine the functional impact of nanoparticle design parameters on cell and organismal developmental and physiological activity.  They utilize a structurally and chemically well-defined library of functionalized gold nanoparticles in bioassays in two model organisms.  The team studies the accumulation of nanoparticles within the organisms to determine sites of biological activity and the impacts of these nanoparticles on viability, gene expression and development.  That data will feed back into nanoparticle design, informing the development of nanoparticles that have minimal impact on organisms.

Use biologically derived ligands to control the shape and size of the nanoparticles

One method of producing potentially benign nanoparticles is to utilize nature’s blueprints to create novel nanoparticles. We are using biological ligands to control the shape and size of nanoparticles by selecting and identifying ligands that bind to specific faces of crystalline gold particles. The use of biological ligands allows us to tap the specificity of these ligands to target nanoparticle delivery. By using ligands that originate from biological systems, the likelihood of creating safe and biocompatible nanomaterials is increased.

    Synthesis and surface modification of nanoparticles – develop biologically safer nanoparticles while also directing self-assembly reactions and optimizing interactions with devices

    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 places 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 being explored.

    Developing greener nanomanufacturing for functionalized nanoparticles

    The aim of this effort is to develop greener approaches of nanoparticle production. We will identify acceptable nanoparticle formation reactions that can be carried out in a single solvent phase and that will permit control of particle size. From these studies we will scale up production and develop an integrated microreactor platform for deploying the single solvent phase chemistries. We are also exploring gas-phase production of ceramic nanoparticles in microreactors to produce materials that should expand our capabilities to produce novel devices for sensors and medicine.

    Jim Hutchison (UO), Steven Kevan (UO), Chih-hung Chang (OSU), Brian Paul (OSU), Vincent Remcho (OSU), Sundar Atre (OSU), Shoichi Kimura (OSU), Goran Jovanovic (OSU), Vinod Narayanan (OSU),

    Develop reaction conditions to control nanoparticle size, size dispersity and functionality in microcapillary reactors

    Currently, most nanoparticle syntheses suffer from a lack of product selectivity and reaction inefficiency.  Poor selectivity leads to ill-defined materials, as measured by size, shape, polydispersity, composition and external functionality.  Poor selectivity and reaction inefficiency both lead to low yields and consumption of excessive amounts of raw materials and result in wasteful, solvent-intensive purification procedures.  We aim to develop methods of producing or manufacturing nanoparticles using methods that are efficient and minimize waste, while producing the well-defined materials needed for high-performance applications.  Our approach focuses on the use of microcapillary or microchannel reactor platforms.  Toward this aim, the ability to monitor the growth of nanoparticles within these micro-environments is essential and is the focus of this research area.   The knowledge gained from these experiments will enhance our understanding of the mechanisms of nanoparticle growth and guide the use of microreactors in manufacturing larger quantities of particles with well-defined properties.

      Develop integrated microreactor platform for scaling up production as well as controlling shape and size of nanoparticles

      Scale-up manufacturing of these nanoparticles is integral to development of novel nanodevices. Thus, we aim to develop reliable and reproducible methods for manufacturing uniformly sized inorganic nanoparticles in microsystems. The initial work will focus on gold nanoparticles, which are attractive because of the possibility of manufacturing them with exacting size and shape specificity.  The specific findings of batch reaction investigations will guide rational design of the microreactors.  Key components of the reactor include conduits for fluid transport, valves for reagent introduction, mixing chambers, reaction domains with thin film heaters for reaction control, integrated waveguides for monitoring and feedback control, separation/sorting operations for product purity control, and functionalization chambers for nanoparticle surface modification.

        Apply the unique attributes of the microreactors to produce ceramic nanoparticles in the gas phase

        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.

          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.

          Shane Addleman (PNNL), Glen Fryxell (PNNL), Jim Hutchison (UO), Richard Taylor (UO), Mark Lonergan (UO), Gertrude Rempfer (PSU), David Johnson (UO), Douglas Kezler (OSU)

          Bottom-up, self-assembly based approach to produce 1D, 2D and 3D nanoparticle arrays

          We will develop bottom-up, self-assembly based approaches to produce 1D and 2D nanoparticle arrays.  The approaches provide access to structures that are inaccessible using state-of-the-art patterning methods and are more material efficient than more wasteful top-down methods.  The design and use of tailored nanoparticle building blocks allows precise control over interparticle spacing and offers avenues for interfacing to larger scale structures. We will explore nanoparticle surface chemistry and how surface functionality can be used to direct the self-assembly of 3D nanoparticle architectures.  Control of nanoparticle ligand shells will enable sequential self-assembly of nanoparticle hierarchies, ultimately allowing these materials to be tailored to specific chemical processes, devices, sensors and other applications. By developing an understanding of nanoparticle linkage chemistries, it should be possible to create multilayered structures with specific architectures and tailored reactivity.

            Examine electronic properties of integrated nanoparticle-based materials to determine how the interfaces influence charge transport in these materials

            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 will include 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 will be done in the context of developing high performance sensors, adaptive materials, photovoltaics and photodetectors.

              Benign approaches for integrating nanostructures into thin films for applications in electronic materials and thermoelectrics

              We will focus on benign approaches for integrating nanostructures into thin films for applications in electronic materials and thermoelectrics.  The research shall focus on optimizing material performance and production efficiency through developing a fundamental understanding of the material properties and examination of the materials in devices.  The thin film structures may provide an approach to nanoparticle/nanostructure integration. New synthetic approaches developed involving control of diffusion lengths on an Ångstrom scale permit us to prepare new compounds that do not exist on equilibrium phase diagrams or that would be impossible to access via traditional approaches. More recently we have focused on the synthesis and characterization of nanolaminates and superlattices consisting of intergrowths of the constituent compounds. Research is also directed to the synthesis and study of environmentally benign oxide thin films by using simple aqueous-based chemistries.  Nanolaminated structures are being developed to examine fundamental aspects of chemical reactivity and develop new materials and processes applicable in electronics manufacture.

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