Nanomaterials

Improving material properties by manipulating atomic structure at the nanometer scale

Go to Research Project Index for all Research Project Categories.

Ceramic Membrane Water Filtration Combined with Ozonation

In this research, we are developing a novel ozone and catalytic membrane filtration laboratory scale drinking water treatment system to meet USA-EPA Stage 2 D/DBP regulatory requirements. The work is focused on optimizing the system for catalyst coated performance of membranes to control the formation of disinfection by-products (DBPs) such as total trihalomethanes and haloacetic acid. Ozonation by-products (OBPs), including aldehydes, ketones and ketoacids, are monitored and their concentrations are found to decrease with the application of ozone and iron oxide coated membrane filtration, as compared to that observed with either ozonation or uncoated ozonation/membrane filtration. A 5 kD MWCO membrane, coated with 40 layers of iron oxide and sintered at 900°C, combined with ozonation (gaseous ozone concentration of 2.5 g/m3) produced permeate water that met the EPA regulatory requirements for TTHMs and HAAs set under Stage 2 D/DBPs Rule and is effective in reducing the concentrations of ozonation by-products formed.

Investigators (PI is linked): Melissa J. Baumann
Categories: Nanomaterials, Biotechnology, Advanced Ceramic Materials

Nanomaterials (Graphene Nano-Platelets) as Multifunctional Modifiers for Polymers

Much excitement has been generated in recent times with the new research focus on materials and processes at the nanoscale. Polymers containing nanoscale additives and reinforcements (e.g. carbon nanotubes, nanoclays) have been shown to possess new, unique physical and chemical properties allowing them to be utilized in new applications such as interior and exterior accessories for automobiles, structural components for portable electronic devices and films. While a great deal of nanolevel research has focused on exfoliated clay platelets and carbon nanotubes, a natural nanostructured mineral, graphite, is known to consist of layers of carbon atoms (graphene sheets) assembled into a layered material. Graphite is one of the stiffest materials found abundantly in nature, and has excellent mechanical, electrical, thermal, lubrication and barrier properties.

This research project is directed at understanding the properties and processes of exfoliated graphite in order to create a new multifunctional additive for polymers. Research completed in the Drzal Group has already shown that with the appropriate surface treatment, graphene sheets can be exfoliated and dispersed in thermoset or thermoplastic polymers resulting in polymers with excellent stiffness, strength, toughness, electrical conductivity, thermal conductivity, and low coefficient of thermal expansion, electromagnetic shielding properties and high barrier properties as well. Current research is directed at the processing and properties of high performance polymers modified with multifunctional exfoliated graphite nanoplatelets for high capacity battery, high performance fuel cell and membrane applications.

Investigators (PI is linked): Lawrence T. Drzal
Categories: Nanomaterials, Electronic Materials

Carbon Nanotube Synthesis with Microwave Plasma Chemical Vapor Deposition

Carbon nanotubes consist of tiny cylinders of graphite and have superior stiffness, strength, toughness, thermal conductivity, and unique electrical properties. They have many potential applications in nanotechnology. We have synthesized long and highly-aligned carbon nanotubes with a microwave plasma chemical vapor deposition method. The nanotubes are characterized with Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The target applications are in field emission display, electronic devices, and polymer reinforcement.

Investigators (PI is linked): Martin C Hawley
Categories: Nanomaterials

Catalytic transformation of biorenewables to petrochemicals

An important global challenge is the need to eventually replace finite fossil fuels with viable renewable resources. Currently, there are many significant initiatives on converting biomass to alternative fuels, but much less activity on using renewables for petrochemicals production. There is much knowledge on the transformation of crude oil to fuels and chemical feedstocks. However, due to significant differences between crude oil and biomass, these well-tested transformation pathways are not suitable for biomass conversion. In this project, we are developing generic methods for synthesizing catalytic nanoparticles (NPs) and surface modification to attach molecular catalysts (MCs), developing protocols for physical and/or chemical immobilization of catalytic NPs and NP-MC complexes in microfluidic channels, and assessing and optimizing catalytic NPs in both classical and microfluidic reactors. We will use the conversion of lactic acid to glycerol as the model reaction. Fatty acids from plant oils represent another important class of abundant biorenewables. To convert these to petrochemicals, we will anchor molecular catalysts to catalytic bimetallic nanoparticles to obtain NP-MC hybrid (NMH), and assess NMH catalyst effectiveness in microreactors using the hydrogenation of selected fatty acids to petrochemicals as model reactions. This is a collaborative project with Professor Obare (Department of Chemistry at UNCC; adjunct in CHEMS).

Investigators (PI is linked): Robert Y. Ofoli
Categories: Nanomaterials, Colloid and Interface Science, Biotechnology, Biobased Industrial Products, Sustainable Economy

Development of Nanostructured Lead-free Solder

In order to improve the service performance of lead-free electronic solders a sub-micron size inert and stable reinforcement, that bonds extremely well and be present in grain boundary regions of the solder matrix without any agglomeration during processing or coarsening during additional exposure to service environments, is essential. Unluckily, traditionally evaluated approaches utilizing ceramic, metallic and IMC particulate reinforcements or alloying methodologies do not satisfy all these requirements. POSS-silanols containing one to three (Si-OH) groups consist of inert strongly bonded cage structure made of Si-O with surface active groups. As a consequence, the negatively charged -OH surface active groups present in POSS may strongly bond with the metallic matrix, hopefully to the grain boundary regions of the solder. The negatively charged surface active groups present on the surface of POSS should also prevent flocculation of these reinforcements during processing. Since bonding between Si and O is very strong, they will not dissociate in service environments. This will alleviate any coarsening problems that may be encountered during service.

Investigators (PI is linked): Andre Y. Lee
Categories: Nanomaterials, Electronic Materials, Advanced Metallic Systems

Engineering Surfaces and Interfaces

Self-assembly, microcontact printing, and layer-by-layer assembly techniques for surface tuning and patterning are utilized to develop new opto-electronic and bio applications. A variety of materials, such as organic and inorganic molecules, polymers, particles, and biomolecules including cells are used to prepare topologically and functionally structured surfaces for their desired purposes using novel self and directed assembly techniques.

Investigators (PI is linked): Ilsoon Lee
http://www.egr.msu.edu/~leeil/ilsoon_research.html#Ilsoon%20Lee%  Categories: Nanomaterials, Biomaterials, Electronic Materials, Polymer Composites, Structural Materials, Polymer Science and Engineering, Colloid and Interface Science, Biotechnology

Adsorption of liposomes on charged polyelectrolyte substrates (Collaborative with Worden and Lee)

One of the problems with some constructions of biomimetic interfaces using lipid bilayers is that no cushion is provided between the bilayer and the substrate to allow for full insertion of membrane proteins, enable their lateral mobility, and provide for ionic reservoirs on either side of the membrane. The deposition of polyelectrolyte multilayers provides ideal cushions for this purpose, and therefore has potential in biosensor applications. In this project, we are studying the adsorption of fluorescently labeled vesicles on charged polyelectrolyte multilayers (PDAC, PAH, PEG, SPS) deposited on glass slides, using total internal reflection fluorescence microscopy (TIRFM) and fluorescence recovery after pattern photobleaching (FRAPP) to estimate the mobility and lateral diffusion coefficients of the lipids in the bilayer. The resulting interfaces were also characterized by cyclic voltammetry (CV) and quartz crystal microbalance (QCM). This work is being done in collaboration with the research groups of Dr. Ilsoon Lee and Dr. RM Worden.

Investigators (PI is linked): Robert Y. Ofoli
Categories: Biotechnology, Colloid and Interface Science, Biomaterials, Nanomaterials

Opto-electrochemical characterization of bilayer-embedded biomacromolecules in TIR geometry

Membrane-bound enzymes and proteins can serve as ion channels and/or catalyze a variety of biological processes. These processes can be characterized by a variety of techniques, including optics and electrochemistry. In this project, we are developing surface chemistries to enable us to use ITO as an effective electrode on which bilayer lipid membranes can be deposited to provide an electrode platform for simultaneous optical and electrochemical measurements of protein activity. We also have capabilities for physical characterization of biomacromolecules (fluidity and mobility measurements) on planar as well as tethered bilayers by fluorescence recovery after pattern photobleaching (FRAPP) experiments, enabling us to do a complete study of many enzymes and proteins of medical interest.

Investigators (PI is linked): Robert Y. Ofoli
Categories: Nanomaterials, Biomaterials, Colloid and Interface Science, Biotechnology

Self-assembled, Nanostructured Biomimetic Interfaces

Living cells efficiently perform many vital sensing, signaling, catalytic, and bioelectronic processes at the molecular scale. These processes typically occur at cell membranes, whose principal components include a bilayer lipid membrane (BLM) and membrane proteins. The BLM's nanoscale thickness (5 nm) and high electrical resistance give it unique optical and bioelectronic properties. A diverse array of membrane proteins embedded in the BLM imparts the highly specific activities exhibited by cell membranes. These activities can, in principle, be mimicked in the laboratory by reconstituting appropriate membrane proteins into artificial BLM. We are using self and directed assembly tools to fabricate functional and nanostructured biomimetic-interfaces that use lipid bilayers, membrane proteins (such as neuropathy target esterase), and other nanostructured components (e.g. polyelectrolyte multilayers) to reproduce cell-membrane processes. These systems have outstanding potential for conducting fundamental studies of nanoscale biological processes and for developing new technologies, including high-throughput drug screening systems, research tools to study membrane proteins, and high-performance biosensors.

Investigators (PI is linked): Ilsoon Lee
http://www.biomimetic.org/  Categories: Nanomaterials, Biomaterials, Polymer Composites, Structural Materials, Polymer Science and Engineering, Colloid and Interface Science, Biotechnology

Bio-Carbon Nanomaterials

Carbon nanoparticles are available in several geometries, including spherical fullerenes, cylindrical nanotubes and planar nanoplatelets. While these nanoparticles all share the same graphenic structure that imparts semiconductor properties, the diverse geometries afford a spectrum of unique chemical, electrical, magnetic, and optical properties. Composite materials containing carbon nanoparticles electrically coupled to biomolecules could yield an array of high-performance technologies. Inclusion of a biological recognition element, and any necessary cofactor or mediator, allows the composite electrode to serve as an integrated, bioactive electrode unit (i.e., bio-carbon network). This work includes (1) development of simple and rapid methods to modify and process carbon nanoparticles for self and directed assembly, (2) incorporation of the nanoparticles into bio-carbon networks, and (3) characterization of the network’s fundamental properties.

Investigators (PI is linked): Ilsoon Lee
Categories: Nanomaterials, Biomaterials, Polymer Composites, Structural Materials, Polymer Science and Engineering, Colloid and Interface Science, Biotechnology

Transport and Stability in Biocatalytic Fuel Cells

Enzyme electrocatalysts are an attractive alternative to conventional noble metals because of their high selectivity, manufacturability by fermentation techniques, and activity in environments where platinum-group metals are fouled. Until recently, however, they were not considered to be practical catalysts for energy applications because the current density, potential, and stability of the resulting cells were insufficient. We study chemical engineering aspects of the materials and structures used to implement these enzymes in electrodes, such as carbon supports, electronic mediators, and reactant transport mechanisms, in order to improve and maximize the overall performance and stability of bioelectocatalytic systems.

Investigators (PI is linked): Scott Calabrese Barton
Categories: Sustainable Economy, Biomaterials, Nanomaterials

Mixed-feed Direct Methanol Fuel Cells

The need for high energy density, lightweight power sources for demanding portable electronic applications gives incentive to the search for novel fuel cell concepts and approaches that could reduce size, weight, and system complexity. Such power sources could find applications in variety of portable medical devices, computer hardware, and military equipment. We are developing a direct methanol fuel cell (DMFC) system design approach where the fuel (methanol) and air are mixed and fed simultaneously to both the anodes and the cathodes of the fuel cell stack. This approach leads to substantial size and weight reductions by eliminating the need for bipolar flow-field/separator plates and cell seals and by simplifying fluid manifolds. The key issues are the need for selective electrocatalyis at both the anode and cathode and efficient mixing and separation systems upstream and downstream of the fuel cell stack, respectively.

Investigators (PI is linked): Scott Calabrese Barton
Categories: Sustainable Economy, Energy Production, Rheology and Multiphase Flow, Nanomaterials

Novel Fabrication of Nanostructured Particles with an Arbitrary Shape

Convenient methods for the fabrication of complex nanostructures are emerging in the growing field of nanotechnology for novel optical, electrical, magnetic, and also biological functions. Recently we have developed a simple and effective method to produce various kinds of nanostructured particles like nanorice and nanospears (i.e., tapered nanorods) using alumina membrane as templates. The nanocylindrical pores of anodized alumina membranes are filled with spherical polymer nanoparticles by a solvent assisted nano-injection. Then the membranes are heated in an oven above the glass transition temperature of the polymer. Due to the non-uniform heating, non-equilibrium capillary forces, and the wetting property of the polymer nanospheres confined in the nanocylinders, the spherical nanoparticles coalesce to form both aspect ratio and end-shape controlled nanorods which are shaped in the forms of nanorice, nanospears or tapered nanorods. Other novel nanostructures include nanorods, nanograss, nanodisks, and broken nanodonuts using vaious nanomaterials such as polymers, metals, inorganic particles, and biomolecules.

Investigators (PI is linked): Ilsoon Lee
Categories: Rheology and Multiphase Flow, Colloid and Interface Science, Polymer Science and Engineering, Structural Materials, Nanomaterials

Nanomixing or Nanodispersion of Nanomaterials

We have established a strategic partnership with the Primix Corporation to study the nanomixing, nanodispersion, and nanoparticulate processes. Due to the enhanced high shear forces, the dispersed nanomaterials have superior stability in solvents. We are currently studying why it helps the stability of the nanodispersion. The mixer, named T.K. Filmics, uses a multiphase swirling flow to achieve extremely high energy dissipation and achieve the dispersion. The mixer has a stationary outer cylinder, within which an inner cylinder rotates very rapidly. The two phases are introduced separately from the bottom and the particulates are dispersed by shear in the annular region between the two cylinders. The high shear force, thin film mixing system has been newly developed from the conventional mixers by the Primix Corporation located in Japan (http://www.primix.jp/en/index.html).

Investigators (PI is linked): Ilsoon Lee
http://www.primix.jp/en/index.html  Categories: Nanomaterials, Polymer Science and Engineering, Rheology and Multiphase Flow, Colloid and Interface Science

Wrinkle-free Nanomechanical Films

Wrinkling or buckling is a common natural phenomenon which occurs in numerous forms on many different length scales. Common forms of buckling include the wrinkling of human skin, the surface of many dried fruits, and even the formation of mountain ranges. Generally buckling occurs when a stiff upper material on a more compliant substrate is compressed. Compressive forces can be generated physically (e.g., stretching or compressing a compliant substrate) or simply by raising or lowering the temperature of the materials. Wrinkling and related phenomena in various materials have been studied from the standpoint of micro and bio mechanics. How and why wrinkles form has been well studied; however, preventing the occurrence of such a phenomenon remains a challenge. The goal of this proposed work is to study how nanoparticles influence the mechanical (or thermal) wrinkling (or buckling) of thin films, and to develop such wrinkle free films for various applications.

Investigators (PI is linked): Ilsoon Lee
Categories: Biotechnology, Colloid and Interface Science, Polymer Science and Engineering, Structural Materials, Polymer Composites, Nanomaterials