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Timothy E. Long

Professor of Chemistry, and Macromolecules and Interfaces Institute member

Polymer Chemistry

Office: 2110 Hahn Hall South
Phone: 540-231-2480
Fax: 540-231-8517

Group Website:

St. Bonaventure University Chemistry B.S., 1983
Virginia Tech Chemistry Ph.D., 1987

Professional Experience 
2011 Associate Dean for Research and International Outreach, College of Science, Virginia Tech
2009 Associate Director Interdisciplinary Research and Education, Fralin Institute, Virginia Tech
2003 Professor of Chemistry, Virginia Tech
2001 Associate Professor of Chemistry, Virginia Tech
1999 Assistant Professor of Chemistry, Virginia Tech
1993 Principal Research Chemist, Eastman Chemical Company, Kingsport, TN
1993 Senior Research Chemist, Eastman Kodak Company, Kingsport, TN
1991 Advanced Technical Program Researcher (ATP, sponsored by NIST)
1990 Senior Research Scientist, Eastman Kodak Company, Rochester, NY
1987 Advanced Research Scientist, Eastman Kodak Company, Rochester, NY

Awards and Recognition
• Received Robert L. Patrick Fellowship Award in 2014
• Regional Chair, IUPAC World Polymer Congress, MACRO 2012 at Virginia Tech, June 2012
• Inducted into the ACS Polymer Division Fellows program in 2012
• Received the Mark Scholar Award in 2012
• Received Pressure Sensitive tape Council, Carl Dahlquist Award in 2012
• Received PMSE Cooperative Research Award in 2011
• Received the Virginia Tech Alumni Award for Research Excellence for 2010
• Received the honor of American Chemical Society Fellow in 2009
• Elected Chair, Polymers Gordon Research Conference (GRC), summer 2009
• Invited Wake Forest University, Affiliated Professor of the WFIRM Wake Forest Institute for Regenerative Medicine (2008)
• Chair-elect, 2012 Polycondensation Conference (2008)
• Symposium Co-chair, 2012 IUPAC World Polymer Congress (2008)
• IRTF Interdisciplinary Research Team Fellowship Award, with Profs. Duncan and Thatcher
• Collano Innovation Award, Lucerne, Switzerland - September 2006
• Chair-elect, 2009 Polymers (East) Gordon Research Conference (2005)
• Chair, ACS Division of Polymer Chemistry (2005)
• Faculty Research Award, Department of Chemistry (May 2003)
• Panhellenic Council of Virginia Tech Certificate of Appreciation for Teaching Excellence, Spring 2003
• Top Oral Presentation, ASI USER FORUM, June 2002 ($2000 award)
• ACS, Division of Polymer Chemistry, Chair-elect, 2002-2005
• IBM Faculty Award, 2002
• 3M Company Faculty Award, 2000-2001
• Sigma Xi, Professional Fraternity Elected Full Member at VA Tech, 1999
• Faculty Signature Award, GenCorp Co. (OMNOVA), Akron, OH, 1999

Our research goal is to integrate fundamental research in novel macromolecular structure and polymerization processes with the development of high performance macromolecules for advanced technologies. Our research platforms focus on the design, performance, and societal implications of novel biomaterials for the following global impact: (1) gene/drug delivery, (2) tissue regeneration, and (3) biomedical devices.  Our hypothesis states that biomaterial design involves fundamental and common structural parameters for performance and that the integration of biomaterials in various biological environments will involve common interfacial and performance challenges.

The development of efficient, nontoxic materials for the delivery of therapeutic nucleic acids and drugs is a fundamental and important problem in biotechnology research.  For example, while many drugs are available to control cardiovascular disease (a leading global health problem), drug toxicity and lack of specificity leads to serious side effects.  Delivery vehicles have the potential to minimize side effects while maximizing medicinal efficacy, yet fundamental studies on biomaterials-based delivery systems are severely lacking.  Our research team focuses on the development and study of water-soluble polycations, particularly segmented block copolymer structures, for the binding, encapsulation, and delivery of anionic drugs and nucleic acids into cultured cells. We are currently examining structure-property effects of incorporating different cationic groups into these structures such as histidine-mimics and quaternary ammonium and phosphonium groups, and investigate the influence of nucleobase substitution in vector design, which may lead to novel binding strategies.

The tissue regeneration biotechnology seeks to replace failing organs, as opposed to treating the symptoms of underlying disease, functional restoration, improving quality of life. Our research builds on the discovery in the Long laboratories to fabricate nanometer-scale scaffolds based on nature-derived phospholipids and new families of photo-reactive amphiphiles.

Novel biomaterials that can transform the functionality and efficacy of medical devices and offer sustainable treatments with reduced cost are sought throughout the world to improve the quality of life. Recent efforts in our laboratories are focused on biomaterials for stents for sensing force needed to employ a device and also the incidence of tissue re-growth near the device interface with biological structure (Vlachos, Long) and biomaterial alternatives to acid-generation during polylactide absorption. Research efforts are proposed based on the synthesis and characterization of charged polyurethanes for subsequent performance as an elastomeric electromechanical transducer. 

In addition to macromolecular chemistry and engineering at the interface with biology, our research group also addresses fundamental questions involving ionic liquids, charged polymers for electroactive devices, fuel cell membranes, novel adhesives, block copolymer elastomers, high impact engineering thermoplastics, and responsive polymer compositions based on tailored hydrogen bonding and electrostatic interactions.  Recent efforts in self-healing compositions offer promise for novel families of cationic polymers.


1. Buckwalter, D. J.; Inglefield, D. L., Jr.; Enokida, J. S.; Hudson, A. G.; Moore, R. B.; Long, T. E., Effects of Copolymer Structure on the Mechanical Properties of Poly(dimethyl siloxane) Poly(oxamide) Segmented Copolymers. Macromolecular Chemistry and Physics 2013, 214(18), 2073-2082.

2. Hemp, S. T.; Zhang, M.; Allen, M. H., Jr.; Cheng, S.; Moore, R. B.; Long, T.E., Comparing Ammonium and Phosphonium Polymerized Ionic Liquids: Thermal Analysis, Conductivity, and Morphology. Macromolecular Chemistry and Physics 2013, 214(18), 2099-2107

3. Buckwalter, D. J.; Zhang, M.; Inglefield, D. L.; Moore, R. B.; Long, T. E., Synthesis and characterization of siloxane-containing poly(urea oxamide) segmented copolymers. Polymer 2013, 54(18), 4849-4857.

4. Hemp, S. T.; Allen, M. H. Jr.; Smith, A. E.; Long, T. E., Synthesis and Properties of Sulfonium Polyelectrolytes for Biological Applications. ACS Macro Letters 2013, 2(8), 731-735.

5. Zhang, M.; Zhang, M.; Moore, R. B.; Long, T.E., Influence of charge placement on the thermal and morphological properties of sulfonated segmented copolyesters. Polymer 2013, 54(14), 3521-3528.

6. Hemp, S.T.; Zhang, M.; Tamami, M.; Long, T. E., Phosphonium ionenes from well-defined step-growth polymerization: thermal and melt rheological properties. Polymer Chemistry 2013, 4(12), 3582-3590.

7. June, S. M.; Suga, T.; Heath, W. H.; Lin, Q.; Puligadda, R.; Yan, L.; Dillard, D.; Long, T. E., Photoactive Polyesters Containing o-Nitro Benzyl Ester Functionality for Photodeactivatable Adhesion. Journal of Adhesion 2013, 89(7), 548-558.

8. Gao, R.; Zhang, M.; Wang, S.; Moore, R. B.; Colby, R. H.; Long, T. E., Polyurethanes Containing an Imidazolium Diol-Based Ionic-Liquid Chain Extender for Incorporation of Ionic-Liquid Electrolytes. Macromolecular Chemistry and Physics 2013, 214(9), 1027-1036.

9. Tamami, M.; Hemp, S. T.; Zhang, K.; Zhang, M.; Moore, R. B.; Long, T. E., Poly(ethylene glycol)-based ammonium ionenes containing nucleobases. Polymer 2013, 54(6), 1588-1595.

10. Allen, M. H.; Day, K. N.; Hemp, S. T.; Long, T. E., Synthesis of Folic Acid-Containing Imidazolium Copolymers for Potential Gene Delivery Applications. Macromolecular Chemistry and Physics 2013, 214(7), 797-805.

11. Allen, M. H., Jr.; Wang, S.; Hemp, S. T.; Chen, Y.; Madsen, L. A.; Winey, K. I.; Long, T.E., Hydroxyalkyl-Containing Imidazolium Homopolymers: Correlation of Structure with Conductivity. Macromolecules 2013, 46(8), 3037-3045.

12. Gao, R.; Ramirez, S. M.; Inglefield, D. L.; Bodnar, R. J.; Long, T. E., The preparation of cation-functionalized multi-wall carbon nanotube/sulfonated polyurethane composites. Carbon 2013, (54), 133-142.

13. Allen, M. H.; Hemp, S. T.; Zhang, M.; Zhang, M.; Smith, A. E.; Moore, R. B.; Long, T. E., Synthesis and characterization of 4-vinylimidazole ABA triblock copolymers utilizing a difunctional RAFT chain transfer agent. Polymer Chemistry 2013, 4(7), 2333-2341.

14. Wu, T.; Wang, D.; Zhang, M.; Heflin, J. R.; Moore, R. B.; Long, T. E., RAFT Synthesis of ABA Triblock Copolymers as Ionic Liquid-Containing Electroactive Membranes. Applied Materials Interfaces 2012, 4(12), 6552-6559.

15. Nelson, A. M.; Long, T. E., A perspective on emerging polymer technologies for bisphenol-A replacement. Polymer International 2012, 61(10), 1485-1491.

16. Green, M. D.; Wang, D.; Hemp, S.T.; Choi, J-H.; Winey, K. I.; Heflin, J. R.; Long, T. E., Synthesis of imidazolium ABA triblock copolymers for electromechanical transducers. Polymer 2012, 53(17), 3677-3686.

17. Gao, R.; Wang, D.; Heflin, J. R.; Long, T. E., Imidazolium sulfonate-containing pentablock copolymer-ionic liquid membranes for electroactive actuators. Journal of Materials Chemistry 2012, 22(27), 13473-13476.

18. Hemp, S. T.; Smith, A. E.; Bryson, J. M.; Allen, M. H.; Long, T. E., Phosphonium-Containing Diblock Copolymers for Enhanced Colloidal Stability and Efficient Nucleic Acid Delivery. Biomacromolecules 2012, 13(8), 2439-2445.

19. Zhang, M.; Moore, R.B.; Long, T. E., Melt transesterification and characterization of segmented block copolyesters containing 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Journal of Polymer Science, Part A: Polymer Chemistry 2012, 50(18), 3710-3718.

20. June, S. M.; Bissel, P.; Long, T. E., Segmented block copolyesters using click chemistry. Journal of Polymer Science, Part A: Polymer Chemistry 2012, 50(18), 3797-3805.

21. Green, M. D.; Choi, J-H.; Winey, K. I.; Long, T. E., Synthesis of Imidazolium-Containing ABA Triblock Copolymers: Role of Charge Placement, Charge Density, and Ionic Liquid Incorporation. Macromolecules 2012, 45(11), 4749-4757.

22. Allen, M. H.; Hemp, S. T.; Smith, A. E.; Long, T. E., Controlled Radical Polymerization of 4-Vinylimidazole. Macromolecules 2012, 45(9), 3669-3676.

23. Tamami, M.; Salas-de la Cruz, D.; Winey, K. I.; Long, T. E., Structure-Property Relationships of Water-Soluble Ammonium-Ionene Copolymers. Macromolecular Chemistry and Physics 2012, 213(9), 965-972.

24. Suga, T.; Hunley, M. T.; Long, T. E.; Nishide, H., Electrospinning of radical polymers: redox-active fibrous membrane formation. Polymer Journal 2012, 44(3), 264-268.

25. Hemp, S. T.; Hunley, M. T.; Cheng, S.; DeMella, K. C.; Long, T. E., Synthesis and solution rheology of adenine-containing polyelectrolytes for electrospinning. Polymer 2012, 53(7), 1437-1443.

26. Gao, R.; Zhang, M.; Dixit, N.; Moore, R. B.; Long, T. E., Influence of ionic charge placement on performance of polyethylene glycol-based sulfonated polyurethanes. Polymer 2012, 53(6), 1203-1211.

27. Cheng, S.; Zhang, M.; Dixit, N.; Moore, R. B.; Long, T. E., Nucleobase Self-Assembly in Supramolecular Adhesives. Macromolecules 2012, 45(2), 805-812.

28. Hemp, S. T.; Long, T. E., DNA-Inspired Hierarchical Polymer Design: Electrostatics and Hydrogen Bonding in Concert. Macromolecular Bioscience 2012, 12(1), 29-39.

29. Salas-de la Cruz, D.; Green, M. D.; Ye, Y.; Elabd, Y. A.; Long, T. E.; Winey, K. I., Correlating backbone-to-backbone distance to ionic conductivity in amorphous polymerized ionic liquids. Journal of Polymer Science, Part B: Polymer Physics 2012, 50(5), 338-346.

30. Fowler, J. N.; Saito, T.; Gao, R.; Fried, E. S.; Long, T. E.; Green, D. L., Impact of Diblock Copolymers on Droplet Coalescence, Emulsification, and Aggregation in Immiscible Homopolymer Blends. Langmuir 2012, 28(5), 2347-2356.

31. Hemp, S. T.; Allen, M. H.; Green, M. D.; Long, T. E., Phosphonium-containing polyelectrolytes for nonviral gene delivery. Biomacromolecules 2012, 13(1), 231-238.

32. Cheng, S.; Zhang, M.; Wu, T.; Hemp, S. T.; Mather, B. D.; Moore, R. B.; Long, T. E., Ionic aggregation in random copolymers containing phosphonium ionic liquid monomers. Journal of Polymer Science, Part A: Polymer Chemistry 2012, 50(1), 166-173


Timothy E. Long