Prof. Dr. Manfred Wilhelm Head of Max-Planck research group "Polymer mechanics", joint appointment: Technical University Darmstadt Institut für Mechanik Hochschulstr. 1 64289 Darmstadt, Germany phone:   +49-(0)-6151-164140 Max-Planck-Institute for Polymer Research     . Ackermannweg 10  55128 Mainz, Germany phone:   +49-(0)-6131-379 124 fax:        +49-(0)-6131-379 100 e-mail: wilhelm@mpip-mainz.mpg.de

Research Interests
 

	Method development in rheology, specifically non-linear methods under oscillatory  shear: "FT-Rheology" and the two dimensional extensions of FT-Rheology.
	Application of FT-Rheology to polymers, e.g. the influence of different topologies,  long chain branching, surface charges for polymer dispersions or shear induced  crystallization towards the non-linear mechanical response under oscillatory shear.
	Method development in Solid-State-NMR, especially with respect to dynamic  and spatial heterogeneities in the 1 - 100 nm regime. More specifically:  multidimensional exchange NMR and proton spin diffusion.
	Application of Solid-State-NMR to materials and questions of industrial relevance.
	If you are intested to work together in one of these topics, please feel free to send me an e-mail!

CV
 

1966-1985 Grew up on a winefarm in Maikammer/Pfalz 1986-1992 Study of Chemistry at the University of Mainz partly supported  with a stipend of the Friedrich-Ebert-society. 09/1989-03/1990 exchange student at the University of Toronto (Canada) in the  group of Prof. M.A. Winnik (with a scholarship of the DAAD). Topic: detection of CMC  in block copolymers via fluorescence. Diploma 10/1992 Title: Order and mobility in polymers: 1H and 13C  Solid-State NMR in the group of Prof. H.W. Spiess at the  Max-Planck-Institute for Polymer Research in Mainz. Ph.D 07/1995 with the dissertation "Development and application  of multidimensional NMR-methods to detect orientation and dynamics  in inorganic and organic polymers" in the group of Prof. H.W. Spiess. 10/1993-04/1994 visit at the UCSB, Santa Barbara (USA), via a further DAAD stipend. Working in the group of Prof. B.F. Chmelka on the topic: multidimensional  13C-exchange NMR applied to zeolites. Postdoc from 09/1995 to 4/1997 at the Weizmann-Institute (Israel) in  the group of Prof. J. Klein (currently at the University of Oxford, UK) using  the surface forces apparatus (SFA) to characterize adsorbed polyelectrolytes  and dendrimers under confinement and shear. This postdoctoral stay was founded via a MINERVA stipend. Staff scientist from 05/1997 to 10/2004 at the Max-Planck-Institute for Polymer Research  in Mainz in the group of Prof. H.W. Spiess where a habilitation was conducted.  The habilitation is the German equivalent of an assistant professorship. The topic of the habilitation (1997 - 2001) was the development and application  of non-linear mechanical methods for the characterization of materials (see below).  This work was rewarded by the Reimund-Stadler prize of the  Fachgruppe Makromolekulare Chemie (GDCh) in 1999. From 11/2004 Professorship at Technical University Darmstadt in joint cooperation with Max-Planck-Institut for Polymer Research. Head of a Max-Planck research group "Mechanics of Polymers" in the engineering mechanics department.

FT-Rheology
 

The basic idea of FT-Rheology is the application of sinusoidal strain to  materials that respond in a non-linear way. This leads to the appearance  of higher harmonic contributions during a rheological measurement.  The reason why the higher harmonics show up is as follows: Let's assume that we have a viscosity (or the spring constant) that depends  on the applied shear rate: You might ask why the expansion includes only even terms? That's simply due to  the fact that we would like to have the same response if we shear in either direction. Next, we apply oscillatory shear and for simplicity we write this in the complex notation: Now, we put the two equations together in Newton's viscosity law: A Fourier-transformation of the time dependant torque is able to unravel in a  very sensitive way the components of the higher harmonics at odd multiples  of the applied excitation frequency. To detect experimentally the higher harmonics we developed the following set-up: The set-up is basically an extension of a commercial rheometer. Typical S/N reaches  100.000 : 1, the detection of up to 71 harmonics was, in this setup, immediately feasible. If you ask about possible applications of FT-Rheology, you can think about anything  that implies non-linear mechanical response in materials in general because  FT-Rheology as a method is of course not limited to polymers! Here is a small list of projects that are currently under way:   Sensitivity improvement of the experimental set-up Comparison between experimental results and finite-element predictions Shear induced aging and quality control, e.g. for industrial processes Shear induced crystallization Evolution of the higher harmonics during the phase alignment of block-copolymers Relation between cross-link density and hogher harmonics in rubbers Relation between topology and non-linear response Effect of charges, pH and solid content in dispersions towards the non-linear respons

Selected References (full list and/or reprints available on request):
 

Fluorescence measurements on colloids: 1. M. Wilhelm, C. Zhao, Y. Wang, R. Xu, M.A. Winnik, J. Mura, G. Riess, M. Croucher;  Poly(styrene-ethylene oxide) Block Copolymer Micelle Formation in Water: A fluorescence  Probe Study; Macromolecules 24 1033 (1991)   Solid-state-NMR on zeolites: 1. M. Wilhelm, A. Firouzi, D.E. Favre, L.M. Bull, D. Schaefer, B.F. Chmelka;  Dynamics of Benzene Absorbed on Ca-LSX Zeolite Studied by Solid-State  Two-dimensional Exchange 13C NMR; J. Am. Chem. Soc. 117 2923 (1995) 2. D.J. Schaefer, D.E. Favre, M. Wilhelm, S.J. Weigel, B.F. Chmelka;  Site-Hopping Dynamics of Benzene Adsorbed on Ca-LSX Zeolite Studied by  Solid-State Exchange 13C NMR; J. Am. Chem. Soc. 119 9252 (1997)   Heterogeneities in materials, 1H-spin diffusion: 1. M. Wilhelm, H. Feng, U. Tracht, H.W. Spiess;  2D CP/MAS 13C Isotropic Chemical Shift Correlation established by 1H Spin Diffusion; J. Magn. Reson. 134 255 (1998) 2. F. Mellinger, M. Wilhelm, K. Landfester, H.W. Spiess, A. Haunschild, J. Packusch; Structure of water-containing latexes: Remagnetization effects during solid-state NMR  spin-diffusion experiments; Acta Polymer. 49 108 (1998) 3. I. Quijada-Garrido, M. Wilhelm, H.W. Spiess, J.M. Barrales-Rienda;  Solid State NMR Studies of Structure and Dynamics of Erucamide/isotactic-Poly(propylene)  Blends; Macromol. Chem. Phys. 199 985 (1998) 4. F. Mellinger, M. Wilhelm, H.W. Spiess, R. Baumstark, A. Haunschild;  Quantitative Measurement of Core Coverage in Core-Shell Particles by Solid State  1H-NMR Spin-Diffusion Experiments; Macromol. Chem. Phys. 200 719 (1999) 5. F. Mellinger, M. Wilhelm, P. Belik, H. Schwind, H.W. Spiess;  Quantitative Determination of Dynamic Heterogeneities in Core-Shell Latices by 1H-Solid State NMR; Macromol. Chem. Phys. 200 2454 (1999) 6. F. Mellinger, M. Wilhelm, H.W. Spiess;  Calibration of 1H-NMR spin diffusion coefficents for mobile polymers through transverse relaxation measurements; Macromolecules 32 4686 (1999) 7. J. Rottstegge, K. Landfester, M. Wilhelm, H.W. Spiess, C. Heldmann;  Different Types of Water in the Film Formation Process of Latex Dispersions as Detected by Solid State NMR; Colloid & Polymer Science 278 236 (2000) 8. M. Valtier, X. Druion, M. Wilhelm, H.W. Spiess;  Quantitative characterisation of the inner structure of core-shell latex particles by 1H solid  state NMR; Macromol. Chem. Phys. 202 1262 (2001) 9. E. Díez-Peña, I. Quijada-Garrido, J.M. Barrales-Rienda, M. Wilhelm, H.W. Spiess;  NMR studies of the structure and dynamics of polymer gels based on N-isopropylacrylamide  (NiPAAm) and methacrylic acid (MAA); Macromol. Chem. Phys. 203 491 (2002) 10. A. Kretschmer, R. Drake, M. Neidhöfer, M.Wilhelm; Quantification of Composition and Domain Size of Industrial Poly(phthalimide)/Poly(dimethylsiloxane) Block Copolymers using different 1H Solid-State NMR Methods; Solid State Nucl. Magn. Reson. 22 204 (2002) 10. T. Dollase, Y. Yagen, M. Wilhelm, H.W. Spiess, R. Yerushalmi-Rozen, M. Gottlieb; Effects of Interfaces on the Cristallization Behavior of PDMS Interface Science 11 199 (2003) 11. J. Rottstegge, B. Traub, M. Wilhelm, K. Landfester, C. Heldmann, H.W. Spiess; Investigations on the film formation process of latex dispersions by solid-state NMR; Macromol. Chem. Phys. 204 787 (2003) 12. J. Rottstegge, P. Kindervater, M. Wilhelm, K. Landfester, C. Heldmann, J.P. Fischer, H.W. Spiess; The influence of sodium ethene sulfonate comonomer on the film formation process of poly(vinylacetate) dispersions; Colloidal & Polymer Science 282 1111 (2003) 13. A. Domjan, G. Erdödi, M. Wilhelm, M. Neidhöfer, K. Landfester, B. Ivan, H.W. Spiess; Structural Studies of Nanophase Separated Poly(2-hydroxyethylmethacrylate)-l-Polyisobutylene Amphiphilic Conetworks by Solid-State-NMR and Small Angle X-ray Scattering; Macromoecules 36 9107 (2003) Dynamic and spatial heterogeneities in glasses: 1. A. Heuer, M. Wilhelm, H. Zimmermann, H.W. Spiess;  Rate Memory of Structural Relaxations in Glasses and its Detection by Multidimensional NMR; Phys. Rev. Letters 75 2851 (1995) 2. U. Tracht, M. Wilhelm, A. Heuer, H. Feng, K. Schmidt-Rohr, H.W. Spiess;  Length scales of the glass transition as determined by multidimensional NMR; Phys. Rev. Letters 81 2727 (1998) 3. U. Tracht, M. Wilhelm, A. Heuer, H.W. Spiess;  Combined reduced 4D 13C exchange and 1H spin diffusion experiment for determing  the length scale of dynamic heterogeneities; J. Magn. Reson. 140 460 (1999) 4. S.A. Reinsberg, X.H. Qiu, M. Wilhelm, H.W. Spiess, M.D. Ediger;  Length Scale of Dynamic Heterogeneity in Glycerol near Tg;  J. Chem. Phys. 114 7299 (2001)   Miscellaneous NMR on polymers: 1. M. Wilhelm, S. Féaux de Lacroix, J.J. Titman, K. Schmidt-Rohr, H.W. Spiess;  The orientation distribution in an industrial sample of poly(p-phenyleneterephthalamide)  determined by two- and three dimensional NMR techniques; Acta Polymer. 44 279 (1993) 2. M. Wilhelm, S. Lehmann, C. Jäger, H.W. Spiess, R. Jerome; Detection of dynamics and phase separation in polymers using 2D 1H NMR in solids;  Magn. Reson. Chem. 32 3 (1994) 3. M. Wilhelm, H.W. Spiess;  Detection of slow 180° Phenylene Flips in PET-Fibres via 13C Two-dimensional Solid-State Exchange NMR; Macromolecules 29 1088 (1996) 4. M. Wilhelm, M. Neidhöfer, S. Spiegel, H.W. Spiess;  A collection of solid state 13C CP/MAS NMR spectra of common polymers; Macromol. Chem. Phys. 200 2205 (1999) 5. D. Maring, M. Wilhelm, H.W. Spiess, B. Meurer, G. Weill;  Dynamics in the crystalline polymorphic forms I, II and form III of isotactic poly-1-butene; J. Poly. Sci. Part B: Polymer Physics 38 2611 (2000 6.  M. Pollard, K. Klimke, R. Graf, H.W. Spiess, M. Wilhelm, O. Sperber, C. Piel, W. Kaminsky; Observation of chain branching in polyethylene inthe solid-state and melt via 13C-NMR spectroscopy and melt NMR relaxation time measurement; Macromolecules 37 813 (2004) Surface forces apparatus (SFA): 1. X. Zhang, M. Wilhelm, J. Klein, M. Pfaadt, E. W. Meijer;  Modification of Surface Interactions and Friction by adsorbed dendrimers: 1. Low Surface  Energy fifth-Generation Amino-Acid-Modified Poly(propyleneimine) Dendrimers; Langmuir 16 3884 (2000)   FT-Rheology: 1. M. Wilhelm, D. Maring, H.W. Spiess;  Fourier-Transform Rheology; Rheol. Acta 37 399 (1998) 2. M. Wilhelm, P. Reinheimer, M. Ortseifer;  High sensitivity Fourier-Transform Rheology; Rheol. Acta 38 349 (1999) 3. M. Wilhelm, P. Reinheimer, M. Ortseifer, T. Neidhöfer, H.W. Spiess;  The Crossover between linear and non-linear mechanical behaviour in polymer solutions  as detected by Fourier-Transform Rheology; Rheol. Acta 39 241 (2000) 4. C. Daniel, I.W. Hamley, M. Wilhelm, W. Mingvanish;  Non-linear Rheology of a Face-centered Cubic Phase in a Diblock Copolymer Gel;  Rheol. Acta 40 39 (2001) 5. D. van Dusschoten, M. Wilhelm;  Increased Torque Transducer Sensitivity via Oversampling; Rheol. Acta 40 395 (2001) 6. T. Neidhöfer, M. Wilhelm, H.W. Spiess;  Fourier-Transform Rheology on linear polystyrene melts;  Applied Rheology 11 126 (2001) 7. S. Kallus, N. Willenbacher, S. Kirsch, D. Distler, T. Neidhöfer, M. Wilhelm, H.W. Spiess;  Characterization of Polymer Dispersions by Fourier-Transform Rheology  Rheol. Acta 40 552 (2001) 8. D. van Dusschoten, M. Wilhelm, H.W. Spiess;  Two-Dimensional Fourier Transform Rheology J. Rheol. 45 1319 (2001) 9. M. Wilhelm; FT-Rheology; feature article; Macromol. Mater. Eng. 287 83 (2002) 10. M. Langela, M. Wilhelm, U. Wiesner, H.W. Spiess; Microphase reorientation in block copolymer melts as detected via FT-Rheology and 2D-SAXS; Macromolecules 35 3198 (2002) 11. T. Dötsch, M. Pollard, M. Wilhelm; Kinetics of Isothermal Crystallization in isotactic Polypropylene Monitored with  Rheology and FT-Rheology; J. Phys.: Cond. Mat. 15 923 (2003) 12.  K. Hyun, J.G. Nam, M. Wilhelm, K.H. Ahn, S.J. Lee; Non-linear response under large amplitude oscillatory shear flow; Korea-Aust. Rheol. J. 15 97 (2003) 13. T. Neidhöfer, M. Wilhelm, B. Debbaut; Fourier-Transform rheology experiments and finite-element simulations on linear polystyrene solutions; J. Rheol. 46 1351 (2003) 14. S. Filipe, M.T. Cidada, M. Wilhelm, J.M. Maia; Evolution of morphological and rheological properties along the extruder for blends of a commercial liquid crystalline polymer and polypropylene; Polymer 45 2367 (2004) 15. L. Hilliou, D.  van Dusschoten, M. Wilhelm, H. Burhin, E.R. Rodger; Increasing the Torque Sensitivity of an RPA 2000 by a factor 5 - 10 using advanced data acqusition; Rubber Chemistry and Technology 77 192 (2004) 16. T. Neidhöfer, S. Stella, N. Hadjichristidis, M. Wilhelm; Distigushing linear from star-branched polystyrene solutions with Fourier-Transform Rheology; Macromol. Rap. Commun. 25 1921 (2004)