Oklahoma State University

My research group designs and synthesizes new polymeric materials to have specific physical or chemical properties. Catalysts and nanostructured materials are the two major objectives.

Polymeric catalysts are designed to oxidize and hydrolyze organic compounds in aqueous and fluorocarbon media. Potential uses of the catalysts are decomposition of pollutants in industrial waste water, chemical manufacturing in aqueous mixtures without organic solvent, and decontamination of toxic chemicals from fluorocarbon solutions. The fundamental goals to understand how colloidal polymers can be stabilized and how chemical reactions proceed on the surface and within polymer particles in colloidal dispersions. The polymer latexes are made by emulsion and dispersion polymerization using radical initiators and functional monomers that subsequently are converted to catalyst sites. Monodisperse colloidal particles can be ordered into colloidal crystalline arrays for selective diffraction of light, templates for photonic band gap materials, and size selective membrane filters.

Colloidal crystalline array of a monodisperse poly(styrene-co-2-hydroxyethyl methacrylate) latex

Colloidal crystalline array of a monodisperse poly(styrene-co-2-hydroxyethyl methacrylate) latex

Various hydrophobically modified dendrimers behave as surfactants in water or form monolayers on the surface of water and on crystal surfaces. A potential application of the dendrimers is a passivation layer at the interface of the electrode and the electrolyte of solid state lithium ion batteries.

 Structure of a fatty acid modified poly(propylene imine) dendrimer

Structure of a fatty acid modified poly(propylene imine) dendrimer.

 

High resolution atomic force micrograph of the fatty acid modified dendrimer.

High resolution atomic force micrograph of the fatty acid modified dendrimer.

High resolution atomic force micrograph of the fatty acid modified dendrimer.

Exceptional mechanical strength, high thermal conductivity and electrical conductivity, either metallic or semiconducting, make single-walled carbon nanotubes (SWNT) a major focus of research in nanotechnology. Dispersion into solution and processing into devices are two of the big challenges that must be met before SWNT will be practical. We have devised methods for the grafting of polymers to and from single-walled carbon nanotubes for dispersion into water, into organic solvents, and into the parent polymers for mechanical reinforcement and for electrical conductivity.

AFM of a Nanotube

Atomic force micrograph of SWNT grafted with poly(butyl methacrylate). The arrows indicate 2.3 nm height difference.

Surface Attachment Scheme

 

Model for a growing polymer radical adding to the surface of a bundle of single-walled carbon nanotubes and wrapping around individual tubes

Students working on these research projects gain experience in monomer and polymer synthesis, spectroscopic characterization of materials, and applications as catalysts, surfactants, and multiphase solid state materials. The lab is equipped with UV, HPLC and SEC, spin coating, and centrifugation instruments. In service facilities at OSU we analyze materials by liquid and solid state NMR spectroscopy, mass spectrometry, scanning probe microscopy, and electron microscopy. Materials research often requires collaboration between research groups having complimentary expertise. We excel at synthesis and primary chemical characterization of materials. We collaborate with researchers at OSU and around the world to characterize our materials, to gain fundamental understanding of the relationships between the structures and the properties of the new polymers, and to explore their potential applications.


Recent Publications

  1. Qin, S.; Qin, D.; Ford, W. T.;* Resasco, D. E.; Herrera, J. E., Functionalization of Single Walled Carbon Nanotubes with Polystyrene via Grafting to and Grafting from Methods, Macromolecules 2004, 37, 752-757.
  2. Qin, D.; Tan, S.; Qin, S.; Ford, W. T.,* Monitoring the Transformation of Colloidal Crystals by Styrene Vapor Using Atomic Force Microscopy, Langmuir 2004, 20, 3145-3150.
  3. Sherman, R. L., Jr.; Chen, Y.; Ford, W. T.,* Cadmium Sulfide and Cadmium Selenide/Cadmium Sulfide Nanoparticles Stabilized in Water with Poly(cysteine acrylamide), J. Nanosci. Nanotech. 2004, 4, 1032-1038.
  4. Qin, S.; Qin, D.; Ford, W. T.;* Herrera, J. E.; Resasco, D. E.; Lian, G.; Bachilo, S.; Weisman, R. B., Solubilization and Purification of Single-Wall Carbon Nanotubes by In Situ Radical Polymerization of Sodium 4-Styrenesulfonate, Macromolecules 2004, 37, 3965-3967.
  5. Tan, S.;* Sherman, R. L., Jr.; Ford, W. T.,* Nanoscale Compression of Polymer Microspheres by Atomic Force Microscopy, Langmuir 2004, 20, 7015-7020.
  6. Murugan, E; Sherman, R. L., Jr.; Spivey, H. O; Ford, W. T.,* Catalysis by Hydrophobically Modified Poly(propylenimine) Dendrimers Having Quaternary Ammonium and Tertiary Amine Functionality, Langmuir 2004, 20, 8307-8312.
  7. Guldi, D. M.;* Ramey, J.; Marcaccio, M.; Paolucci, D.; Paolucci, F.; Qin, S.; Ford, W. T.; Balbinot, D.; Jux, N.; Tagmatarchis, N.; Prato, M.;, Donor-acceptor nanoensembles of soluble carbon nanotubes, Chemical Communications 2004, 2034-2035.
  8. Qin, S.; Qin, D.; Ford, W. T.;* Herrera, J. E.; Resasco, D. E., Grafting of Poly(4–vinylpyridine) to Single Walled Carbon Nanotubes and Assembly of Multilayer Films, Macromolecules 2004, 37, 9963-9967.
  9. Tan, S.,* Sherman, R. L. Jr.; Qin, D.; Ford, W. T.,* Surface Heterogeneity of Polystyrene Latex Particles Determined by Dynamic Force Microscopy, Langmuir 2005, 21, 43-49.
  10. Qin, S.; Qin, D.; Ford, W. T.;* Zhang, Y.; Kotov, N. A., Covalent Cross-Linked Polymer/Single-Wall Carbon Nanotube Multilayer Films, Chemistry of Materials 2005, 17, 2131-2135.
  11. Sherman, R. L., Jr.; Ford, W. T.,* Semiconductor Nanoparticle/Polystyrene Latex Composite Materials, Langmuir 2005, 21, 5218-5222.
  12. Guldi, D. M.;* Rahman, G. M. A.; Prato, M.; Jux, N.; Qin, S.; Ford, W. Single-wall carbon nanotubes as integrative building blocks for solar-energy conversion, Angewandte Chemie, International Edition 2005, 44, 2015-2018.
  13. Sherman, R. L., Jr.; Ford W. T.,* Small Core/Thick Shell Polystyrene/Poly(methyl methacrylate) Latexes, Industrial & Engineering Chemistry Research, 2005, 44, 8538-8541.
  14. Miranda, L. N.; Ford, W. T.,* Binary Copolymer Reactivity of tert-Butyl Methacrylate, 2-(N,N-dimethylamino)ethyl Methacrylate, Solketal Methacrylate, and 2-Bromoethyl Methacrylate, J. Polym. Sci. Part A: Polym Chem. 2005, 43, 4666-4669.
  15. Chen, W.; Tan, S.; Ng, T.-K.; Ford, W. T.; Tong, P.,* Attraction between like-charged colloidal particles at aqueous interfaces, Physical Review Letters 2005, 95, 218301-218304.
  16. Guldi, D. M.;* Rahman, G. M. A.; Qin, S.; Tchoul, M.; Ford, W. T.; Marcaccio, M.; Paolucci, D.; Paolucci, F.; Campidelli, S.; Prato, M., Versatile coordination chemistry towards multifunctional carbon nanotube nanohybrids, Chemistry--A European Journal 2006, 12, 2152-2161.
  17. Chen, W.; Tan, S.; Huang, Z.; Ng, T.-K.; Ford, W. T.; Tong, P.,* Measured long-ranged attractive interaction between charged polystyrene latex spheres at a water-air interface, Physical Review E 2006, 74, 021406/1-021406/14.
  18. Su, A.; Tan, S.;* Thapa, P.; Flanders, B. N.; Ford, W. T.,* Highly Ordered Langmuir-Blodgett Films of Amphiphilic Poly(propylene imine) Dendrimers, Journal of Physical Chemistry C 2007, 111, 4695-4701.
  19. Ha, M. L. P.; Grady, B. P.;* Lolli, G.; Resasco, D. E.; Ford, W. T., Composites of single-wall carbon nanotubes and styrene-isoprene copolymer lattices, Macromolecular Chemistry and Physics 2007, 208, 446-456.
  20. Kim, Y. H.; Ford, W. T.;* Mourey, T. H., Branched Poly(styrene-b-tert-butyl acrylate) and Poly(styrene-b-acrylic acid) by ATRP from a Dendritic Poly(propylene imine)(NH2)64 Core, J. Polym. Sci. Part A: Polym. Chem. 2007, 45, in press.
  21. Tchoul, M. N.; Ford, W. T.;* Lolli, G.; Resasco, D. E.; Arepalli, S., Effect of Mild Nitric Acid Oxidation on Dispersability, Size and Structure of Single-walled Carbon Nanotubes, Chemistry of Materials 2007, 19, in press.