415 South Street
Waltham, MA 02454-9110
Ph.D., University of Mainz, Germany
Our group studies the composition and nanoscale structure of polymer materials, nanocomposites, carbon materials, natural organic matter, and thermoelectric tellurides, using a variety of selective or two-dimensional nuclear magnetic resonance (NMR) experiments, many of which were developed by us. We have also introduced new methods for quantitative analysis of scattering data of nanostructured materials. This dual approach has enabled us to “solve” important aspects of the structure of the Nafion fuel-cell membrane and of the nanocomposite in bone. Based on these structural insights, we strive to understand the materials properties and sometimes propose improved synthesis conditions.
We also re-analyze the basic thermodynamics of irreversible processes.
Structure of Carbon Materials
- H. Pham, A. E. Anderson, R. L. Johnson, T. J. Schwartz, B. J. O’Neill, P. Duan, K. Schmidt-Rohr, J. A. Dumesic, A. K. Datye “Carbon Overcoating of Supported Metal Catalysts for Improved Hydrothermal Stability” ACS Catalysis. 5, 4546–4555 (2015)
- R. L. Johnson, J. M. Anderson, B. H. Shanks, K. Schmidt-Rohr “Simple one-step synthesis of aromatic-rich materials with high concentrations of hydrothermally stable catalytic sites, validated by NMR.” Chem. Mater. 26, 5523-5532 (2014).
- J. M. Anderson, R. L. Johnson, K. Schmidt-Rohr, B. H. Shanks "Solid State NMR of Chemical Structure and Hydrothermal Deactivation of Moderate-Temperature Carbon Materials with Acidic SO3H Sites." Carbon 74, 333–345 (2014).
- H. N. Pham, A. E. Anderson, R. L. Johnson, K. Schmidt-Rohr, A. K. Datye "Improved Hydrothermal Stability of Mesoporous Oxides for Aqueous Phase Reactions” Angew. Chemie Int. Ed. 51, 13163-13167 (2012).
- C. E. Brewer, Y-Y. Hu, K. Schmidt-Rohr, S. D. Joseph, T. E. Loynachan, D. A. Laird, R. C. Brown "Extent of Pyrolysis Impacts on Fast Pyrolysis Biochar Properties" J. Environm. Quality 41, 1115-1122 (2011).
- X-W. Fang, K. Schmidt-Rohr. “Alkyl and Other Major Structures Formed in Model Maillard Reactions Studied by Solid-State NMR” J. Agric. Food Chem. 59, 481-490 (2011).
Structure of Natural Organic Matter
- X. Cao, C. Lattao , J. -J. Pignatello , J. Mao and K. Schmidt-Rohr "Sorption Selectivity in Natural Organic Matter Probed with Carbonyl-13C-Labeled Benzophenone and 1H-13C NMR Spectroscopy" Environ. Sci. Technol. 8, 8645-8652 (2014).
- J. R. Helms, J-D. Mao, A. Stubbins, K. Schmidt-Rohr, R. Spencer, P. Hernes, K. Mopper "Loss of optical and molecular indicators of terrigenous dissolved organic matter during long-term photobleaching" Aquatic Sciences 76, 353-373 (2014).
- J. Mao, R. L. Johnson, J. Lehmann, D. C. Olk, E. G. Neves, M. L. Thompson, K. Schmidt-Rohr “Abundant and Stable Char in Soil: Implications for Soil Fertility and Carbon Sequestration”, Environ. Sci. Technol. 46, 9571-9576 (2012).
- J. Mao, X-W. Fang, Y. Lan , A. Schimmelmann , M. Mastalerz , L. Xu and K. Schmidt-Rohr "Chemical and Nanometer Structure of Kerogen and its Change During Thermal Maturation investigated by advanced solid-state 13C NMR spectroscopy" Geochim. Cosmochim. Acta 74, 2110-2127 (2010).
NMR Technique Development
- R. L. Johnson, K. Schmidt-Rohr “Quantitative Solid-State 13C NMR Spectra with Signal Enhancement by Multiple Cross-Polarization”, J. Magn. Reson. 239, 44-49 (2014).
- R. L. Johnson, J. M. Anderson, B. H. Shanks, X-W. Fang, M. Hong, K. Schmidt-Rohr “Spectrally Edited 2D 13C-13C NMR Spectra without Diagonal Ridge for Characterizing 13C-Enriched Low-Temperature Carbon Materials” J. Magn. Reson., 234, 112-124 (2013).
- K. Schmidt-Rohr, K. J. Fritzsching, S. Y. Liao, M. Hong. “Spectral Editing of Two-Dimensional Magic-Angle-Spinning Solid-State NMR Spectra for Protein Resonance Assignment and Structure Determination”. J. Biomol. NMR 54, 343 (2012).
- Y.Y. Hu, K. Schmidt-Rohr “Technical Aspects of Fast Magic-Angle Turning NMR for Dilute Spin-1/2 Nuclei with Broad Spectra” Solid State NMR 40, 51-59 (2011).
- Klaus Schmidt-Rohr "Why Combustions Are Always Exothermic, Yielding About 418 kJ per Mole of O2". J. Chem. Educ. (2015). DOI: 10.1021/acs.jchemed.5b00333.
- K. Schmidt-Rohr “Expansion Work without the External Pressure, and Thermodynamics in Terms of Quasistatic Irreversible Processes”, J. Chem. Educ. 91, 402-409 (2014).
- K. Schmidt-Rohr, J. Cui “Reply to a ‘Comment on “Quantification of C=C and C=O Surface Carbons in Nanodiamond by NMR”’” J. Phys. Chem. C, in press (2015)
- J-F. Cui, X-W. Fang, K. Schmidt-Rohr “Quantification of C=C and C=O Surface Carbons in Nanodiamond by NMR” J. Chem. Phys. C 118, 9612-9627 (2014).
- X.-W. Fang, J.-D. Mao, E. M. Levin, K. Schmidt-Rohr “Nonaromatic Core-Shell Structure of Nanodiamond from Solid–State NMR” J. Am. Chem. Soc.131, 1426-1435 (2009).
- Rawal, X. Kong, Y. Meng, J. Otaigbe, K. Schmidt-Rohr “Reduced crystallinity and mobility of nylon-6 confined near the organic-inorganic interface in a phosphate-glass-rich composite detected by 1H-13C NMR” Macromolecules 44, 8100-8105 (2011).
- Y-Y. Hu, X. Liu, X. Ma, J. Yang, A. Rawal, M. Akinc, T. Prozorov, S. Mallapragada, K. Schmidt-Rohr “Biomimetic Self-assembling Copolymer–Hydroxyapatite Nanocomposites with the Nanocrystal Size Controlled by Citrate” Chem. Mater. 23, 2481-90 (2011).
- Y.-Y. Hu, A. Rawal, K. Schmidt-Rohr "Strongly bound citrate stabilizes the apatite nanocrystals in bone" Proc. Natl. Acad. Sci. USA 107, 22425-22429 (2010).
Nafion Fuel Cell Membrane
- X. Kong, K. Schmidt-Rohr “Water–Polymer Interfacial Area in Nafion: Comparison with Structural Models” Polymer 52, 1971-1974 (2011).
- K. Schmidt-Rohr, Q. Chen “Parallel Cylindrical Water Nanochannels in Nafion Fuel Cell Membranes”, Nat. Mater. 7, 75-83 (2008).
- S. N. Girard, K. Schmidt-Rohr, T. C. Hasapis, B. Njegic, E. M. Levin, A. Rawal, K. M. Paraskevopoulos, M. Kanatzidis, “Chemical Analysis of Phase Separation in PbTe – PbS Thermoelectric Materials” Adv. Funct. Mater. 23, 747-757 (2013).
- E. M. Levin, S. L. Budko, K. Schmidt-Rohr “Enhancement of thermopower of TAGS-85 high-performance thermoelectric material via doping with Dy”. Adv. Funct. Mater. 22, 2766-2774 (2012).
- M. D. Nielsen, E. M. Levin, C. M. Jaworski, K. Schmidt-Rohr, J. P. Heremans “Chromium as resonant donor impurity in PbTe”, Phys. Rev. B 85, 045210 (2012).
For a complete list of publications, see the complete Curriculum Vitae (PDF).