Research

Areas of Research in the Tour Group at Rice University

Graphene as a New Material for Various Exciting Applications

Our group has participated in the vigorous growth of the graphene research field with a number of papers funded by different agencies. We have developed methods of making graphene nanoribbons (GNRs) from multi-walled carbon nanotubes (MWCNTs) and have rapidly expanded this area of research. New projects include the use of graphene in drilling fluids funded by M-I-SWACO. The following papers are representative: Sun, Z.; Yan, Z.; Yao, J.; Beitler, E.; Zhu, Y.; Tour, J. M. “Growth of Graphene from Solid Carbon Sources,” Nature 2010, 468, 549-552; Zhu Y.; Tour, J. M. “Graphene Nanoribbon Thin Films Using Layer-by-Layer Assembly,” Nano Lett. 2010, 10, 4356-4362; Zhu, Y.; Higginbotham, A. L.; Tour, J. M. “Covalent Functionalization of Surfactant-Wrapped Graphene Nanoribbons,” Chem. Mater. 2009, 21, 5284-5291; Hamilton, C. E.; Lomeda, J. R.; Sun, Z. ; Tour, J. M.; Barron, A. R. “High-Yield Organic Dispersions of Graphene,” Nano Lett. 2009, 9, 3460-3462; Zhang, Z.; Sun, Z.; Yao, J.; Kosynkin, D. V.; Tour, J. M. “Transforming Carbon Nanotube Devices into Nanoribbon Devices,” J. Am. Chem. Soc. 2009, 131, 13460-13463; Price, B. P.; Lomeda, J.; Tour, J. M. “Aggressively Oxidized Ultra-Short Single-Walled Carbon Nanotubes Having Oxidized Sidewalls,’ Chem. Mater. 2009, 21, 3917-3923; Jin, Z.; Lomeda, J. R.; Price, B. P.; Lu, W.; Zhu, Y.; Tour, J. M. “Mechanically Assisted Exfoliation and Functionalization of Thermally Converted Graphene Sheets” Chem. Mater. 2009, 21, 3045-3047; Kosynkin, D. V.; Higginbotham, A. L.; Sinitskii, A.; Lomeda, J. R.; Dimiev, A.; Price, B. K.; Tour, J. M. “Longitudinal Unzipping of Carbon Nanotubes to Form Graphene Nanoribbons,” Nature 2009, 458, 872-826; Lomeda, J. R.; Doyle, C. D.; Kosynkin, D. V.; Hwang, W.-H.; Tour, J. M. “Diazonium Functionalization of Surfactant-Wrapped Chemically Converted Graphene Sheets,” J. Am. Chem. Soc. 2008, 130, 16201-16206.

Nanomachines, Synthesis and Testing; NSF NIRT

This research, which is funded by The Robert A. Welch Foundation and the National Science Foundation, through the Penn State Center for Nanoscience and a NIRT at Rice, is focused on the synthesis of nanomachines such as nanocars, nanotrucks, motorized nanocars, and other machines that can roll on surfaces and do work at the nanoscale. The synthesis of the first nanocar took almost 10 years to complete, and the imaging of the nanocars moving on a surface by our Rice collaborator Prof. Kevin Kelly, was almost as difficult yet luckily did not take as long. This work has opened up a plethora of opportunities to design and synthesis new nanomachines. For representative publications see: Vives, G.; Kang, J.; Kelly, K. F.; Tour, J. M. “Molecular Machinery: Synthesis of a Nanodragster,” Org. Lett. 2009, 11, 5602-5605; Claytor, K.; Khatua, S.; Guerrero, J.; Tcherniak, A.; Tour, J. M.; Link, S. “Accurately Determining Single Molecule Trajectories of Molecular Motion on Surfaces,” J. Chem. Phys. 2009, 130, 164710-1-9; Khatua, S.; Guerrero, J. M.; Claytor, K.; Vives, G.; Kolomeisky, A. B.; Tour, J. M.; Link, S. “Monitoring of Individual Nanocars on Glass,” ACS Nano 2009, 3, 351-356; Vives, G.; Tour, J. M. “Synthesis of Single-Molecule Nanocars,” Acc. Chem. Res. 2009, 42, 473-487; Vives, G.; Tour, J. M. “Synthesis of a Nanocar with Organometallic Wheels,” Tetrahedron Lett. 2009, 50, 1427-1430; Sasaki, T.; Guerrero, G.; Leonard, A. D.; Tour, J. M. “Nanotrains and Self-Assembled Two-Dimensional Arrays Built from Carboranes Linked by Hydrogen Bonding of Dipyridones” Nano Res. 2008, 1, 412-419; Sasaki, T.; Guerrero, J. M.; Tour, J. M. “The Assembly Line: Self-Assembling Nanocars,” Tetrahedron, 2008, 64, 8522-8529; Kimov, A. V.; Nemukhin, A. V.; Moskovsky, A. A.; Kolomeisky, A. B.; Tour, J. M. “Molecular Dynamics of Surface-Moving Thermally Driven Nanocars” J. Chem. Theory Comput. 2008, 4, 652-656; Sasaki, T.; Osgood, A. J.; Kiappes, J. L.; Kelly, K. F.; Tour, J. M. “Synthesis of a Porphyrin-Fullerene Pinwheel,” Org. Lett. 2008, 10, 1377-1380; Sasaki, T.; Tour, J. M. “Synthesis of a New Photoactive Nanovehicle: Nanoworm,” Org. Lett. 2008, 10, 897-900; Sasaki, T.; Osgood, A. J.; Alemany, L. B.; Kelly, K. F.; Tour, J. M. “Synthesis of a Nanocar with an Angled Chassis. Towards Circling Movement,” Org Lett. 2008, 10, 229-232; Morin, J.-F.; Sasaki, T.; Shirai, Y.; Guerrero, J. M.; Tour, J. M. “Synthetic Routes toward Carborane-Wheeled Nanocars,” J. Org. Chem. 2007, 72, 9481-9490; Shirai, Y.; Morin, J.-F.; Sasaki, T.; Guerrero, J.; Tour, J. M. “Recent Progress on Nanovehicles,” Chem. Soc. Rev. 2006, 35, 1043-1055; Morin, J.-F., Shirai, Y.; Tour, J. M. “En Route to a Motorized Nanocar,” Org. Lett. 2006, 8, 1713-1716; Shirai, Y.; Osgood, A. J.; Zhao, Y.; Yao, Y.; Saudan, L.; Yang, H.; Yu-Hung, C.; Alemany, L. B.; Sasaki, T.; Morin, J.-F.; Guerrero, J.; Kelly, K. F.; Tour, J. M. “Surface-Rolling Molecules,” J. Am. Chem. Soc. 2006, 128, 4854-4864; and Shirai, Y.; Osgood, A. J.; Zhao, Y.; Kelly, K. F.; Tour, J. M. “Directional Control in Thermally Driven Single-Molecule Nanocars,” Nano Lett. 2005, 5, 2330-2334. This publication was the most accessed paper of all papers published by the American Chemical Society in 2005.

Synthesis, Flurescence Imaging and Tracking of Inherently Fluorescent Single-Molecule Nanocars

Project Summary: The primary objective of this project is to build surface-rolling nanomachines (called nanocars) that can convert optical energy inputs into controlled translational motion on a surface as monitored through single-molecule optical imaging techniques. This will be done by uniting the synthetic expertise of the PI, Tour, with the complementary optical imaging and measurement expertise of the co-PIs, Link and Marti, to propel the field of nanomachine development through simplified imaging and tracking methods. Imaging and tracking is currently the major slow step in nanomachine development and we hope to overcome this barrier through the combined expertise and approach here.

Intellectual Merit and Broader Impact: The movement of objects at the nano-level generally remains painstakingly difficult. Nanomanipulators are often 8-9 orders of magnitude larger than the individual nano-entity that they are intended to manipulate, and they only manipulate one nano-sized entity at a time. Following biology’s lead, there may be a better way to manipulate nano-sized objects by using machines that are close in size to the entities that need manipulation. For example, enzymes can be viewed as nature’s nanomachines as they control the transport and placement of molecular-sized entities for the construction of higher order structures. As nature often propels the nanoscale transporters using gross fields of influence, i.e. blood flow made possible by the heart, we too may find that gross fields, such as electric field gradients, are the optimal way to manipulate nano-sized cargo carriers. While we are investigating the use of passive transporters, we seek to study active transporters that have imbedded nanomotors that could be actuated by light. Therefore, transport of goods and materials between points is at the heart of all engineering and construction in real-world systems. Just as biological systems survive by nanometer-scale transport using molecular-sized entities, as we delve into the arena of the nano-sized world, it beckons that we learn to manipulate and transport nanometer-scale materials, and particularly upon surfaces under ambient conditions. Through this work, students and post doctoral associates will be trained in organic synthesis and the development of new imaging and tracking techniques, while propelling the burgeoning field of nanomachine development.

To promote science educational outreach efforts nationally and internationally through the NSF’s broader educational goals of bringing new scientific concepts to the masses, we are using the Internet as a medium for the dissemination of Dance Dance Revolution (DDR) and Guitar Hero (GH) packages that showcase grades 6-8 science curricula (Earth Science, Life Science and Physical Science, respectively) through communal games while particularly targeting broader ages 9-15, the precise age range where interest in science is often lost. Coordination with professionals in the Cognitive Science Department at Rice University will provide critical efficacy evaluations. Music and dance have been tools of learning since ancient times. In the more recent past, music was used for television-based education throughout the 1960s and 70s; science concepts were often translated by “singing to the bouncing ball,” thereby highlighting fundamental principles through lyrics. Here, fundamental science concepts from science text books are converted into modern lyrics that are then used to formulate DDR and GH music and step charts via StepMania and Jamming packages. We seek to demonstrate the utility of communal recreation, through the dancers and the observers (the latter can observe the scrolling lyrics), and afforded by freely available packages through web-based downloads onto school or home computers. The SciRave/SciJam experience will be coupled through lyrics to highlight fundamentals that are learned during classroom study. Using a modern genre in which students are familiar, the long-regarded dovetailing of music and dance with education will be recreated. The downloads can be accessed at www.scirave.org and this initial program will be augmented with the funds here. The proposed effort builds upon our successful NanoKids introduction of fundamental chemistry, physics, and biology concepts into middle schools that was done over a period of several years and used with over 15,000 children throughout the country that specifically targeted at-risk and underrepresented student groups. See: http://nanokids.rice.edu/.

Publications arising from this project include: Vives, G.; Guerrero, J. M.; Godoy, J.; Khatua, S.; Wang, Y.-P.; Kiappes, J. L.; Link, S.; Tour, J. M. “Synthesis of Fluorescent Dye-Tagged Nanomachines for Single-Molecule Fluorescence Spectroscopy,” J. Org. Chem. 2010, 75, 6631–6643.

Functionalized Graphite Oxide Flame Retardants (A project that has been completed)

This project is concerned with the production of new flame retardant materials for use in commercial aircraft to give passengers of a survivable crash additional time to get out of the aircraft before they succumb to deadly gases and smoke. This project is funded by the Federal Aviation Administration and concerns the addition of graphite oxide and its derivatives to impart flame retardance to materials. Representative publications from this and prior FAA-funded work are: Higginbotham, A. L.; Lomeda, J. R.; Morgan, A. B.; Tour, J. M. “Graphite Oxide Flame-Retardant Polymer Nanocomposites,” App. Mater. Interfac. 2009, 1, 2256-2261; Morgan, A. B.; Jurs, J.; Stephenson, J.; Tour, J. M., “Flame Retardant Materials: Non-Halogenated Additives from Brominated Starting Materials and Inherently Low-Flammability Polymers,” in Encyclopedia of Chemical Processing, Lee, S., Ed.; Taylor & Francis, Inc; New York, 2005; pp.1879-1895 and Stephenson, J. J.; Jurs, J. L.; Tour, J. M. “Vinyl Bisphenol C for Flame Retardant Polymers,” Proceedings of the Society for the Advancement of Material and Process Engineering, Long Beach 2004 Vol. 49.

NanoKids Educational Outreach and SciJam/SciRave

This educational outreach project involves the synthesis of molecules that resemble people. Animated videos featuring these characters and others from the world of NanoPut have been used as educational tools for outreach projects intended to bring more people into the sciences. With SciRave/SciJam, the group seeks to demonstrate the utility of communal recreation, through the dancers and the observers, afforded by freely available packages through web-based downloads onto school-based or home computers. The SciRave/SciJam experience will be coupled through lyrics to key fundamentals that are learned during classroom study. Using a modern genre in which students are familiar, the long-regarded dovetailing of music and dance with education will be recreated. We expect to bring more students into the sciences by illustrating the fun and excitement of chemistry via animation and fun characters. Funding was provided by a SGER grant through the NSF, which has ended. Partial funding of this project was through the NSF and its funding of the CBEN here at Rice. Partial funding was also provided by NASA through the URETI TiiMS project. Additional funding has been provided by the NSF through a NIRT. The concept is Copyright James M. Tour 2006.

Traumatic Brain Injury Consortium and Alliance for Nanohealth Seed Grants

Single wall carbon nanotubes (SWCNTs) have many interesting properties.  In the past few years much interest has been generated in the medical field as to the possibility of using SWCNTs or functionalized SWCNTs to carry various payloads into organisms to produce biological effects.  These payloads could be drugs, sensors, visualization aids, or combinations of these and more.  The term “nanovector” has been coined to describe nanoscale particles used for such medicinal purposes.  This is an area of rapidly growing research within our group, and we have expanded the reach of the project from SWCNTs to ultra-short SWCNTs (US-SWCNTs) and now hydrophillic carbon clusters (HCCs). Representative publications include Berlin, J. M.; Leonard, A. D.; Pham, T. T.; Sano, D.; Marcano, D. C.; Yan, S.; Fiorentino, S.; Milas, Z. L.; Kosynkin, D. V.; Price, B. K.; Lucente-Schultz, R. M.; Wen, X.; Raso, M. G.; Craig, S. L.; Tran, H. T.; Myers, J. N.; Tour, J. M. “Effective Drug Delivery, In Vitro and In Vivo, by Carbon-Based Nanovectors Noncovalently Loaded with Unmodified Paclitaxel,” ACS Nano 2010, 4, 4621-4636; Lucente-Schultz, R. M.; Moore, V. C.; Leonard, A. D.; Price, B. K.; Kosynkin, D. V.; Lu, M.; Partha, R.; Conyers, J. L.; Tour, J. M. “Antioxidant Single-Walled Carbon Nanotubes,” J. Am. Chem. Soc. 2009, 131, 3934-3941; Shi, X.; Sitharaman, B.; Pham, Q. P.; Spicer, P. P.; Hudson, J. L.; Wilson, L. J.; Tour, J. M.; Raphael, R. M.; Mikos, A. G. “In Vitro Cytotoxicity of Single-Walled Nanotube/Biodegradable Polymer Nanocomposites,” J. Biomed. Mater. Res. A 2008, 813-823; and Tasciotti, E.; Liu, X.; Bhavane, R.; Plant, K.; Leonard, A. D.; Price, B. K.; Cheng, M. M.-C.; Decuzzi, P.; Tour, J. M..; Robertson, F.; Ferrari, M. “Multistage Silicon Particles as a Multistage Delivery System for Imaging and Therapeutic Applications,” Nature Nanotech. 2008, 3, 151-157. These projects are funded by the Army Research Office and the Alliance for Nanohealth.

SBIR Nano-Device Memory Platform

We continue to work in the area of molecular and nano-material electronics. We are participating in a SBIR funded by the Army Research Office through PrivaTran LLC to develop nano-device memory platforms. Representative publications include: Sinitskii, A.; Fursina, A. A.; Kosynkin, D. V.; Higginbotham, A. L.; Natelson, D.; Tour, J. M. ‘Electronic Transport in Monolayer Graphene Nanoribbons Produced by Chemical Unzipping of Carbon Nanotubes,” App. Phys. Lett. 2009, 95, 253108-1-3; Li, Y.; Chen, M.; Chen, B.; Tour, J. M. “Fluoride-Decorated Oxides for Large Enhancement of Conductivity in Intrinsic Silicon Nanowires,” J. Nanosci. Nanotech. 2009, 9, 6470-6477; Sinitskii, A.; Tour, J. M. “Lithographic Graphitic Memories,” ACS Nano 2009, 3, 2760-2766; He, T.; Corley, D. A.; Lu, M.; Di Spigna, N. H.; He, J.; Nackashi, D. P.; Franzon, P. D.; Tour, J. M. “Controllable Molecular Modulation of Conductivity in Silicon-Based Devices,” J. Am. Chem. Soc. 2009, 131, 10023-10030.

Other Active Projects in the Tour Group

Other active projects in the Tour group include “Cloning Single Wall Carbon Nanotubes for Hydrogen Storage” funded by the Department of Energy (Leonard, A. D.; Hudson, J. L.; Fan, H.; Booker, R. Simpson, L. J.; O’Neill, K. J.; Parilla, P. A.; Heben, M. J., Pasquali, M.; Kittrell, C.; Tour, J. M. “Nanoengineered Carbon Scaffolds for Hydrogen Storage,” J. Am. Chem. Soc. 2009, 131, 723-738); “Light-Weight, Low-Loss Dielectric Polymer Composites Containing Carbon Nanostructures” funded by the Air Force Office of Scientific Research (based on furthering the results from the following paper: Higginbotham, A. L.; Stephenson, J. J.; Smith, R. J.; Killips, D. S.; Kempel, L. C.; Tour, J. M., “Tunable Permittivity of Polymer Composites through Incremental Blending of Raw and Functionalized Single-Wall Carbon Nanotubes,” J. Phys. Chem. B. 2007, 111, 17751-17754); a University of California at Berkeley MURI funded by the ONR to develop graphene-based devices; and the Advanced Energy Consortium-funded project “Nanoreporters” in which we will use functionalized carbon nanomaterials to help determine compositions downhole in oil wells.