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Thieo E. Hogen-Esch

Professor of Chemistry
Organic and Polymer Chemistry

MSc. Polymer Chemistry, University of Leiden, Netherlands, 1961
PhD. (Cum Laude) Physical Organic Chemistry, University of Leiden, Netherlands, 1967
Office: LHI 123
Phone: (213) 740-5980
Fax: (213) 740-6679
Email: hogenesc@usc.edu


Research Focus

 

Research in Polymers and Materials Science.

The Hogen-Esch group is focused on the synthesis of polymers using advanced methods in all areas of polymer synthesis aimed at the fabrication of new materials with potential in energy and other materials science fields. Applications include: fuel cell and ultrafiltration/reverse osmosis membranes and polymers reinforced with perfluorocarbon clusters. Current areas of interest include:

A. Non-thermodynamic self-assembled polymer blends with hydrophilic nano-sized channels.
These are made from polymer blends consisting of commercially available polyvinylidenefluoride (PVDF) that is mixed with a styrene sulfonate copolymer. Heating to crosslink the copolymer and rapid quenching in water followed by ion exchange with sulfuric acid transforms the blend into a nano-structured hyper-branched polystyrene sulfonic acid suspended in the PVDF matrix. This material offer interesting perspectives, including their use as fuel cells and water purification. The research here will be aimed at understanding this expanding this concept into similar meta-stable polymer composites. These will include a number of promising blends of elastomeric and glassy polymers that will make it possible to optimize properties such as polymers with enhanced toughness. Examples are blends of high volume polymers such as polystyrene and polyisoprene or polybutadiene elastomers.

B. Synthesis of blends polymers end-functionalized with perfluorocarbon (RF) groups for reverse osmosis and other applications.
We have shown that the presence of perfluorocarbon (C8F17) and longer end groups greatly enhances cohesive forces in synthetic polymers that show major increases in strength (elastic and loss moduli) and thermal stabilities. These studies are being carried out in collaboration with the Professor Nutt group (Dept. of Chemical Engineering and Materials Science). RF end -functionalized polymers also allow the formation of different polymers to be mixed at the molecular level, giving rise to nano-structured polymer blends. The properties of such unusual blends remain largely unexplored. An intriguing example incorporates a suitable hydrophobic polymer such as polyacrylic acid or poly(2-acrylamido- 2-methyl propane sulfonic acid are expected to show enhanced water permeation with potential as ultrafiltration or reverse osmosis membranes.

Selected publications

 

  1. Yurdacan, M., Franke, O. Hogen-Esch, T. E. “Nanoindentation of Films of Perfluorotridecyl, Perfluorodecyl, and Perfluoroheptyl End-Functionalized Polystyrene at the Micron Scale.” Macromol. Chem. Phys. 2016, 217, 1260–1269.
     
  2. Piunova, V. A.; Hogen-Esch, T. E. “Synthesis of telechelic perfluorocarbon functionalized polystyrene and polybutylmethacrylate and characterization of their blends”Polymer 2015, 69, 58-65.
     
  3. Deng, C., Peng J., Shen, X.B., Ling J., Hogen-Esch T. E. “White Light Emission of Multi-Chromophore-Photoluminescent Nanoparticles using Polyacrylate Scaffolds Copolymers with Pendent Polyfluorene Groups.” Polymer Chemistry 2014, 05(17), 5109-5115.
     
  4. Lin, Y.; Zheng, Z.; Hogen-Esch, T. E.; Ling, J.; Shen, Z. “Well-Defined Novel Fluorene-Containing Polymers: Synthesis, Fluorescent Properties and Micellization Behaviors” J. Colloid Interface Sci. 2013, 390, 105-113.
     
  5. Nossarev G G.; Johnson, J.M.; Bradforth S. E.; Hogen-Esch T. E. Emission of Macrocyclic and Linear Poly(2-vinylnaphthalene): Observation of Two Excimer Populations in Macrocycles. J. Phys. Chem., 2013, 117(20), 10244-10256.
     
  6. Shen J, Piunova V.A, Nutt S, Hogen-Esch T.E. “Blends of Polystyrene and Poly (n-Butyl Methacrylate) Mediated by Perfluorocarbon End Groups, Polymer, 2013, 54, (21) 5790–5800.
     
  7. Lin, Y., Zheng, Z., Hogen-Esch, T. E., Ling, J., Shen, Z.). Well-defined novel fluorene-containing polymers: synthesis, fluorescent properties, and micellar nanoparticles. Journal of colloid and interface science. 2013, Vol. 390 (1), pp. 105-13.
     
  8. Shi, F.T. ; Ling, J. ; Lu, J.M.; Han, B.Y. ; Liu, L. ; Hogen-Esch, T.E. Synthesis of isotactic polystyrene in hydrocarbons by initiation with t-BuLi in the presence of sodium dodecylbenzenesulfonate. Polymer 2012, 53(1), 94-105.
     
  9. You, L.; Hogen-Esch, T. E.; Zhu, Y.; Ling J,; Shen, Z. “Brønsted Acid-Free Controlled Polymerization of Tetrahydrofuran Catalyzed by Recyclable Rare Earth Triflates in the Presence of Epoxides”. Polymer. 2012, 19, 1953-1058 (Aug).
     
  10. Ring-Opening Polymerization of epsilon-Caprolactone Catalyzed by Yttrium Trisphenolate in the Presence of 1,2-Propanediol. Do Both Primary and Secondary Hydroxyl Groups Initiate Polymerization? Jun Ling, Jinzhi Liu, Zhiquan Shen, Thieo E. Hogen-Esch J. Polym. Sci. A. 2011, 49 (9) 2081-2089.
     
  11. Zhuang, D.; Hogen-Esch T. E. “Controlled Color Output Through Fluorescent Polymer Nano-Pigments” Macromolecules, 2010, 43 (19), 8170–8176.
     
  12. Hogen-Esch, T. E., Fominna, N., Bradforth, S. E. (). Synthesis and Spectroscopy of Poly(9,9-dihexylfluorene-2,7-dlyl-co-9, 9-dihexylfluorene-3,6-diyl)s and Their Model Oligomers. Macromolecules 2009. Vol. 42 (17), pp. 6440-6447.
     
  13. Hogen-Esch, T. E., Chen, R., Ling, J.). Synthesis and Spectroscopic Studies of Macrocyclic Polystyrene Containing Two Fluorene Units and Single 9, 10-Anthracenylidene Group. JACS, 2009, Vol. 42 (16), pp. 6015-6022.
     
  14. Ling, J., Hogen-Esch, T. E., Shen, j. (). A density functional theory study of the mechanisms of scandium-alkoxide initiated coordination-insertion ring-opening polymerization of cyclic esters. Polymer, 2009, Vol. 50 (15), pp. 3575-3581.
     
  15. Hogen-Esch, T. E., Iyer, P., Van Beylen, M. 1,4-Dilithio-1,1,4,4-tetraphenylbutane in Diethyl Ether: An Effective Initiator for the Living Anionic Polymerization of Dienes. Journal of Polymer Science Part A-Polymer Chemistry. 2009, Vol. 47 (8), pp. 2198-2206.
     
  16. Johnson, J. M., Chen, R., Moskun, A., Zhang, X., Hogen-Esch, T. E., Bradforth, S. E. (). Investigation of Macrocyclic Polymers as Artificial Light Harvesters: Sub-Picosecond Energy Transfer In Poly(9,9-Dimethyl-2-Vinyl-Fluorene). Journal of Physical Chemistry, 2008, Vol. 112, pp. 16367-16382.
     
  17. Hogen-Esch, T. E., Ling, J., Fomina, N., Golam, R. (). DFT based Monte Carlo Simulations of poly(9,9-dialkyifluorene-2,7-diyl) polymers in solution. Journal of Physical Chemistry, 2008 Vol. 112 (33), pp. 10116-10122.
     
  18. Hogen-Esch, T. E., Fomina, N. Synthesis and characterization of macrocyclic poly(fluorene-3,6-diyl). Macromolecules, 2008, Vol. 41 (11), pp. 3765-3768.
     

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