- Research Associate Professor of Materials Science & Engineering
|Office:||337 Roberts Hall|
Ph.D., Nankai University, Department of Chemistry, and Chinese Academy of Sciences, Institute of Photographic Chemistry, 1997
B.S., Nankai University, Department of Chemistry, 1992
Organic and polymer chemistry, molecular self-assembly, surface and interface engineering, supramolecular nanostructures, micro/nanopatterning, bio-inspired materials, organic-bio-nano hybrids, electronic/photonic/biosensing materials
Nanostructured materials represent a fascinating class of materials whose structural elements such as atomic clusters, crystallites or molecules have dimensions in the range of 1 to 100 nm, the length scale that defines physical properties of materials and at which intriguing phenomena are observed due to quantum phenomena. They exhibit unique electrical, optical, magnetic and sensing properties that are readily tunable through controlling their size, and enable novel applications that are impossible to realize with their bulk counterparts. Synthesis and processing of nanostructured materials have come a long way. Methods have now been established to obtain monodisperse nanocrystals of various metallic and semiconducting materials, fullerenes of distinct properties, single- and multi-wall carbon nanotubes. Novel organic nanomaterials such as supramolecular nanostructures, polymeric dendrimers with tailored functionalities, as well as other nanophase constructs, are being actively developed. One key step towards novel applications of nanostructured materials concerns their surface functionalization, assembly, patterning, orientation and alignment into functional networks without mutual aggregation. Among the bottom-up strategies, self-assembly provides a promising route to build up complex systems with immense flexibility in terms of nanoscale building blocks and resulting functionalities and properties. As the name suggests, self-assembly is a process in which organization of colloidal, macromolecular, or supramolecular units into the desired system occurs through nature-intended phenomena, either mediated by physicochemical pathways or assisted by biomolecules to promote molecular selectivity and specificity. Current research is focused mainly on the combination of molecular/biomacmolecular self-assembly and nanostructured materials for electronic, photonic and biological applications.
Surface and Interface Engineering via Molecular Self-Assembly
Molecular self-assembly on metal (Au, Ag) and semiconductor (Si, GaAs) surfaces: self-assembly of p-conjugated molecules to understand diversified molecule-molecule and molecule-substrate interactions and to have novel nanoelectronic and optical behaviors.
Interfacial engineering of metal oxide substrates (ITO, SiO2/Si, Al2O3, TiO2): self-assembly of functional (dipolar or hole-transporting) phosphonic acids to enhance charge injection/separation, reduce charge traps and increase charge mobility of organic semiconductors by monolayer-mediated ordering for optoelectronics (LED, FET, PV).
Surface functionalization of nanomaterials (NP, QD, nanowire): molecular self-assembly on nanosurface to tune the properties of nanostructures, such as charge injection/separation for optoelectronics, and water-solubility, biocompatibility, stability, toxicity, circulating, biodegradability and multifunctionality (targeting, probing and drug delivery) for bioimaging/nanomedicine
- Patterned assembly of nanomaterials via genetically engineered proteins for inorganics (GEPI) and self-assembled monolayer (SAM): surface chemistry to build patterned, multi-component and 2D/3D hybrid structures of SAMs, biomacromolecules and nanomaterials
- Bio-nanophotonics (plasmonics) and biosensing: surface plasmon-modulated fluorescence, and metal-molecule-metal charge transfer and/or surface-enhanced Raman scattering (SERS) through spatially-organized nanostructures
Supramolecular Nanostructures of p-Conjugated Materials
- Formation of supramolecular nanostructures: design, synthesis and processing of p-conjugated molecules with non-covalent intermolecular interactions such as hydrogen bonding, p-p stacking, metal-ion coordination, electrostatic, dipolar, and quadrupolar interactions. Combination of easy-to-process and single-crystal-like properties
- Supramolecular electronics/photonics: crosslinking, assembly, patterning and alignment of supramolecular nanostructures to tailor a large number of unprecedented properties such as charge transport, energy/charge transfer and light harvesting
Selected Recent Publications
- Yip, H. L., Ma, H., Jen, A. K.-Y., Dong, J. C., Parviz, B. A., "Two-Dimensional Self-Assembly of 1-Pyrylphosphonic Acid: Transfer of Stacks on Structured Surface", J. Am. Chem. Soc. 2006, 128, 5672.
- Dong, J. C., Yip, H. L., Ma, H., Jen, A. K.-Y., Parviz, B. A., "Gated Lateral Charge Transport in Self-assembled 1-Pyrylphosphonic Acid Molecular Multilayers", Appl. Phys. Lett. 2006, 88, 223112.
- Zin, M. T., Yip, H. L., Wong, N. Y., Ma, H., Jen, A. K.-Y., "Arrays of Covalently Bonded Single Gold Nanoparticles on Thiolated Molecular Assemblies", Langmuir 2006, 22, 6346.
- Dou, R. F., Ma, X. C., Yip, H. L., Lau, W. M., Xue, Q. K., Ma, H., Jen, A. K.-Y., et al, "Self-Assembled Monolayers of Aromatic Thiols Stabilized by Parallel-Displaced p-p Stacking Interactions", Langmuir 2006, 22, 3049.
- Boddapati, S. R., Ma, H., Bordia, R. K., Jen, A. K.-Y., "Interfacial-Shear Strength of the Perfluorocyclobutane Films on Silicon", J. Mater. Res. 2006, 21, 1759.
- Barto, R. R., Frank, C. W., Bedworth P. V., Taylor R. E., Anderson, W. W., Ermer, S., Jen, A. K.-Y., Luo, J. D., Ma, H., Tang, H. Z., Lee, M, Ren, A. S., "Bonding and Molecular Environment Effects on Near-Infrared Optical Absorption Behavior in Nonlinear Optical Monoazo Chromophore-Polymer Materials", Macromolecules 2006, in press.
- Kang, M. S., Kang, S. H., Ma, H., Kim, K. S., Jen, A. K.-Y., "Efficient Photocurrent Generation through a Self-assembled Monolayer of C60-Mercaptophenylanthrylacetylene", J. Power Sources 2006, in press.
- Zin, M. T., Ma, H., Sarikaya, M., Jen, A. K.-Y., "Assembly of Gold Nanoparticles Using Genetically Engineered Polypeptides", Small 2005, 1, 698.
- Krapchetov, D. A., Ma, H., Jen, A. K.-Y., Fischer, D. A., Loo, Y. L., "Solvent-Dependent Assembly of Terphenyl- and Quaterphenyldithiol on Gold and Gallium Arsenide", Langmuir 2005, 21, 5887.
- Ma, H., Kang, M. S., Xu, Q. M., Kim, K. S., Jen, A. K.-Y., "Thiol-Linked Anthraquinone Anthryl Acetylene Molecule: Synthesis, Self-assembly, and Photoelectrochemical Properties", Chem. Mater. 2005, 17, 2896.
- Niu, Y. H., Ma, H., Xu, Q. M., Jen, A. K.-Y., "High-Efficiency Light-Emitting Diodes Using Neutral Surfactants and Aluminum Cathode", Appl. Phys. Lett. 2005, 86, 083504.
- Kang, S. H., Ma, H., Kang, M. S., Kim, K. S., Jen, A. K.-Y., Zareie, M. H., Sarikaya, M., "Ordered Self-Assembly and Electronic Behavior of C60-Anthrylphenylacetylene Hybrid", Angew. Chem. Int. Ed. 2004, 43, 1512.
- Kim, K. S., Kang, M. S., Ma, H., Jen, A. K.-Y., "Highly Efficient Photocurrent Generation from a Self-Assembled Monolayer Film of a Novel C60-Tethered 2,5-dithienylpyrrole Triad", Chem. Mater. 2004, 16, 5058.
- Ma, H., Jen, A. K.-Y., "Functional Self-assemblies for Photocurrent Generation", The Spectrum 2004, 17(3), 24.
- Wong, S., Ma, H., Jen, A. K.-Y., Barto, R., Frank, C. W., "Perfluorocyclobutane-Based Polyester(arylene ether)s for Applications in Integrated Optics", Macromolecules 2004, 37, 5578.
- Luo, J. D., Haller, M., Ma, H., Liu, S., Kim, T. D., Tian, Y. Q., Chen, B. Q., Jang, S. H., Dalton, L. R., Jen, A. K.-Y., "Nanoscale Architectural Control and Macromolecular Engineering of Nonlinear Optical Dendrimers and Polymers for Electro-Optics", J. Phys. Chem. B 2004, 108, 8523.
- Ma, H., Luo, J. D., Kang, S. H., Wong, S., Kang, J. W., Jen, A. K.-Y., Barto, R., Frank, C. W., "Highly Fluorinated and Crosslinkable Dendritic Polymer for Photonic Applications", Macromol. Rapid Commun. 2004, 25, 1667.
- Tai, O. Y. H., Wang, C. H., Ma, H., Jen, A. K.-Y., "Wavelength Dependence of First Molecular Hyperpolarizability of a Dendrimer in Solution", J. Chem. Phys. 2004, 121(12), 6086.
- Zareie, M. H., Ma, H., Reed, B. W., Jen, A. K.-Y., Sarikaya, M., "Controlled Assembly of Conducting Monomers for Molecular Electronics", Nano Lett. 2003, 3, 139.
- Liu, S., Haller, M. A., Ma, H., Dalton, L. R., Jang, S. H., Jen, A. K.-Y., "Focused Microwave-Assisted Synthesis of 2,5-Dihydrofuran Derivatives as Electron Acceptors for Highly Efficient Nonlinear Optical Chromophores", Adv. Mater. 2003, 15, 603.
- Wong, S., Ma, H., Jen, A. K.-Y., Barto, R., Frank, C. W., "Highly Fluorinated Trifluorovinyl Aryl Ether Monomers and Perfluorocyclobutane Aromatic Ether Polymers for Optical Waveguide Applications", Macromolecules 2003, 36, 8001.
- Kang, S. H., Luo, J. D., Ma, H., Barto, R. R., Frank, C. W., Dalton, L. R., Jen, A. K.-Y., "A Hyperbranched Aromatic Fluoropolyester for Photonic Applications", Macromolecules 2003, 36, 4355.
Professional Service and Membership
- Referee for Adv. Func. Mater., Nanotechnology, Optics Lett., Optics Commun., and Crys. Growth & Design
- Referee for proposals from Department of Defense (DOD), and U.S. Civilian Research and Development Foundation (CRDF)
- Member of the American Chemical Society, Materials Research Society
- 2006 - Present, Research Assistant Professor, Department of Materials Science & Engineering, University of Washington, Seattle
- 2001 - 2006, Research Scientist, Department of Materials Science & Engineering, University of Washington, Seattle
- 2000 - 2001, Research Associate, Department of Materials Science & Engineering, University of Washington, Seattle
- 1997 - 1999, Visiting Scientist, Department of Chemistry, Northeastern University, Boston
UW Department of Materials Science & Engineering
phone: (206) 543-2600
fax: (206) 543-3100