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Michael J. Solomon

Michael Solomon

Professor of Chemical Engineering & Macromolecular Science and Engineering

3410 G.G. Brown
(734) 764-3119
FAX: (734) 764-7453
mjsolo@umich.edu

Assembly and microdynamics of nanocolloidal suspensions; confocal laser scanning microscopy and light scattering; complex fluid rheology; polymer science and fluid dynamics

Solomon Research Group Page

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Biographical Information

Curriculum Vitae (PDF)

Mike Solomon is Professor of Chemical Engineering and Professor of Macromolecular Science and Engineering at the University of Michigan.  He was previously Dow Corning Assistant Professor of Chemical Engineering and has been member of the Michigan Faculty since 1997.  Prior to joining U-Michigan, Mike was a post-doctoral research fellow at the University of Melbourne, Australia.  He received his B.S. in chemical engineering and economics from the University of Wisconsin at Madison in 1990 and his Ph.D. in chemical engineering from the University of California at Berkeley in 1996.  He was a Rotary Foundation International Fellow in economics at the Université d’Aix-Marseille II, Aix-en-Provence, France from 1990-1991.


Mike’s research interests are in the area of complex fluids – soft materials with properties intermediate between fluids and solids. His group has applied new 3D confocal microscopy methods to generate discoveries in nanocolloidal assembly, colloidal gelation, and the biomechanics of bacterial biofilms.  His work has also included discovery of a universal scaling for polymer scission in turbulence that identifies the limits that scission imposes on turbulent drag reduction.  Other research interests have included the rheology of polymer nanocomposites, the microrheology of complex fluids and the microfluidic synthesis of anisotropic particles.


Mike’s teaching interests have included development of undergraduate courses in polymer science and engineering, molecular engineering, and chemical engineering process economics as well as graduate electives in nano and colloidal assembly and light scattering.  Mike has received the College of Engineering 1938E Award (2002), the University of Michigan Russel Award (2003), the UM ASEE Outstanding Professor of the Year Award (2006), the Rackham Graduate School’s Faculty Recognition Award (2008) and the COE Education Excellence Award (2010).  He has been recipient of the NSF CAREER award as well as 3M’s non-Tenured Faculty award.

Mike has served as Chair of the Society of Rheology’s Education Committee (2005-2010) and is currently chair of its Metzner Award Committee.  He also served as Chair of the Fluid Mechanics Programming Committee of AIChE (Area 1j) (2008-2010).

 

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Research Interests

Our research investigates complex fluids – soft materials with properties intermediate between fluids and solids.  Our current interests include nanocolloidal assembly, colloidal gelation, and the biomechanics of bacterial biofilms.  Applications that interest us include creating new optical materials, sensors, biomedical devices and procedures, as well as materials for energy management.  

Nanocolloidal assembly
The assembly of nanocolloids into useful structures has long been a key aim of chemical engineers and materials scientists. For example, ordered arrays of colloidal particles formed in the liquid state can be further processed to yield photonic crystal structures useful for sensing and optical materials. Yet, the success of this technological aim is severely hindered by some deep fundamental problems. For example, the crystal structures that have been fabricated to date are disappointingly small, most likely because typical nanocolloidal building blocks are not nearly complex as molecules.  We address this challenge by synthesizing anisotropic colloids and assembling them with the assistance of applied electric, shear and gravitational fields.  We collaborate with Profs. Sharon Glotzer, Mark Burns and Joanna Millunchick in pursuit of this aim.  In a second effort, we address the fact that the typical size of the ordered arrays that have been produced in academia is currently too small for real-world applications.  In collaboration with Professor Ron Larson, we have investigated the complex fluid dynamics of large-scale methods for colloidal crystal production, such as spin coating.  These questions are studied within a collaborative, student-drive research program that includes novel colloid synthesis, direct visualization of assembly structure and dynamics by confocal microscopy as well as rheological measurements.

Colloidal gelation
Colloidal gelation is a common industrial process to manage the rheological and microstructural properties of complex fluid formulations used in the stabilization of consumer products, ceramic materials and pharmaceutical formulations.  By developing new 3D confocal microscopy methods, our group has made fundamental discoveries about gels that are currently being applied in industry to develop new materials and complex fluid processing methods.  Currently, we are engaged in an investigation of the origin of rupture and yielding in colloidal gels.  The work involves a combination of advanced microscopy techniques, flow cell fabrication using methods such as microfabrication, and rheological measurements.

Biomechanics of bacterial biofilms
With Dr. John Younger of the U-Michigan Department of Emergency Medicine and collaborators at two other universities, we are exploring the biomechanical properties of bacterial biofilms.  Biofilms are colonies of microorganisms that are pervasive in a range of natural and industrial settings.  They can also grow on devices, such as intravascular catheters, that are introduced into the body as part of medical practice.  Biofilm structure and mechanics is thought to play a protective role by, for example, improving the resistance of bacteria to antibiotic treatments.  The aim of this project is to understand and measure the mechanical properties of biofilms of size about 10 - 100 microns, since these dimensions match the scales relevant to medical practice.  As part of this work, we have developed a flexible microfluidic rheometer for micromechanical measurements of bacterial biofilm elasticity.  Current work is focused on molecular characterization of the extracellular polysaccharides present in biofilms, rheological characterization of whole biofilms, and confocal microscopy visualization of the complex microscopic structure of biofilms.

Our research is supported by NSF, NIH and ACS-PRF as well as a gift from the Procter & Gamble Company.

 

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Publications

  1. Solomon, M.J., “Directions for targeted self-assembly of anisotropic colloids from statistical thermodynamics,” Current Opinion in Colloid Interface Science, in press (2011).

  2. Dzul, S.P., M.M. Thornton, D.N. Hohne, D.M. Bortz, M.J. Solomon and J.G. Younger, “Contribution of the Klebsiella pneumoniae Capsule to Bacterial Community Microstructure Determined With High-Resolution Confocal Microscopy,” Applied and Environmental Microbiology in press (2011).

  3. Bryne, E., D.M. Bortz, S. Dzul, M.J. Solomon and J. Younger, “Postfragmentation density function for bacterial aggregates in laminar flow,” Phys. Rev E. in press (2011).

  4. Mukhija, D. and M.J. Solomon, “Nematic order in suspensions of colloidal rods by application of a centrifugal field,” Soft Matter, 7 540-545 (2011).

  5. Elbing, B., M.J. Solomon, M. Perlin, D. Dowling and S.L. Ceccio, “Degradation of Drag-Reducing Polymer Solutions within a High-Reynolds Number Turbulent Boundary Layer,” J. Fluid Mechanics 670 337-364 (2011).

  6. Shereda, L.T., R.G. Larson, and M.J. Solomon, “Shear banding in crystallizing colloidal suspensions,” Korea-Australia Rheology Journal 22(4) 309-316 (2010).

  7. Shereda, L.T., R.G. Larson, and M.J. Solomon, “Boundary-driven colloidal crystallization in simple shear flow,” Physical Review Letters, 105 228302 (2010).

  8. Iacovella, C.R., R.E. Rogers, S.C. Glotzer and M.J. Solomon, “Pair interaction potentials of colloids by extrapolation of confocal microscopy measurements of collective structure,” J. Chem. Phys. 133 art no 164903 (2010).

  9. Zeitoun, R., D. Chang, S. Langelier, J. Millunchick, M. J. Solomon and M.A. Burns, “Selective Arraying of Complex Particle and Cell Pattern,” Lab on a Chip 10 1142-1147 (2010).

  10. Solomon, M.J., “Reconfigurable colloids,” Nature 464 496-498 (2010).

  11. Solomon, M.J. and P.T. Spicer, “Microstructural regimes of colloidal rod suspensions, gels, and glasses,” Soft Matter, 6 1391-1400 (2010).

  12. Solomon, M.J. R. Zeitoun, D. Ortiz, K.E. Sung, A. Shah, M.A. Burns, S.C. Glotzer, J.M. Millunchick, “Toward assembly of open colloidal structures from anisotropic pentamer particles,” Macromolecular Rapid Communications 31 196-201 (2010).

  13. Kogan, M and M.J. Solomon, “Electric-field induced yielding of colloidal gels in microfluidic capillaries,” Langmuir, 26(2) 1207-1213 (2010).

  14. Elbing, B.R., E.S. Winkel, M.J. Solomon and S.L. Ceccio, “Degradation of homogeneous polymer solutions in large diameter, high shear turbulent pipe flow,” Experiments in Fluids 47 1033-1044 (2009).

  15. Wilkins, G.M.H., P.T. Spicer and M.J. Solomon, “Nanocolloidal system to explore structural and dynamical transitions in rod networks, gels and glasses,” Langmuir 25 8951-8959 (2009).

  16. Hohne, D.N., J.G. Younger and M.J. Solomon, “Flexible microfluidic device for mechanical property characterization of soft viscoelastic solids such as bacterial biofilms,” Langmuir 25 7177-7768 (2009).

  17. Long, Z., A.M. Shetty, M.J. Solomon and R.G. Larson, “Fundamentals of magnet-actuated droplet manipulations on an open hydrophobic surface,” Lab on a Chip 9 1567-1575 (2009).

  18. Shetty, A.M., G.M.H. Wilkins, J. Nanda and M.J. Solomon, “Multi-angle depolarized dynamic light scattering of single-walled carbon nanotubes,” J. Phys. Chem. C 113 7129-7133 (2009).

  19. Winkel, E.S., G. Oweis, S.A. Vanapalli, D.R. Dowling, M. Perlin, M.J. Solomon and S.L. Ceccio, “High Reynolds number turbulent boundary layer friction drag reduction from wall-injected polymer solutions,” Journal of Fluid Mechanics 621 259-288 (2009).

  20. Shetty, A.M. and M.J. Solomon, “Aggregation in dilute solutions of high molar mass poly(ethylene oxide) and its effect on polymer turbulent drag reduction,” Polymer 50(1) 261-270 (2009).

  21. Shereda, L.T., R.G. Larson and M.J. Solomon, “Local stress control of spatiotemporal ordering of colloidal crystals in complex flows,” Physical Review Letters, 101 art no 038301 (2008).

  22. Hohne, D.N., H-Y Chen, J. Lahann and M.J. Solomon, “Near-surface structure of lithographic ink-fountain solution emulsions on model substrates,” Colloids and Surfaces A, 326 138-146 (2008).

  23. Dibble, C.J., M. Kogan and M.J. Solomon, “Structural origins of dynamical heterogeneity in colloidal gels,” Physical Review E 77 art no 050401(R) (2008).

  24. Yin, G. and M. J. Solomon, “Soft glassy rheology model applied to the stress relaxation of a thermoreversible colloidal gel,” Journal of Rheology 52 785-800 (2008).

  25. Vanapalli, S.A., C.R. Iacovella, K.E. Sung, D. Mukhija, J.M. Millunchick, M.A. Burns, S.C. Glotzer, M.J. Solomon, “Assembly and packing of spheres in confined microchannels for anisotropic particle synthesis,” Langmuir 24 3661-3670 (2008).

  26. Kogan, M., C.J. Dibble, R.E. Rogers and M.J. Solomon, “Viscous solvent colloidal system with well-characterized interactions for direct visualization of suspension structure, dynamics and rheology,” Journal Colloid Interface Science 318 252-263 (2008).

  27. Sung, K.E., S.A. Vanapalli, D. Mukhija. H. McKay, J.M. Millunchick, M.A. Burns and M.J.Solomon, “Programmable fluidic production of microparticles with configurable anisotropy,” J. Am. Chem. Soc., 130 1335-1340 (2008).

  28. Poeckh, T. S. Lopez, O.A. Fuller, M.J. Solomon and R.G. Larson, “Silica-based nucleic acid purification microchip: principles and application to influenza A detection” Analytical Biochemistry 373 253-262 (2008).

  29. Mukhija, D. and M.J. Solomon, “Translational and rotational dynamics of colloidal rods by direct visualization with confocal microscopy,” Journal Colloid and Interface Science 314 98-106 (2007).

  30. Glotzer, S.C. and M.J. Solomon, “Anisotropy of building blocks and their assembly into complex structures,” Nature Materials 6 557-562 (2007).

  31. Dibble, C.J., M. Kogan and M.J. Solomon, “Structure and dynamics of colloidal depletion gels: coincidence of transitions and heterogeneity,” Phys Rev E, 74 art no. 041403 (2006).

  32. Vanapalli, S.A., S.L. Ceccio and M.J. Solomon, “Universal scaling for polymer chain scission in turbulence,” Proceedings of the National Academy of Sciences 103(45) 16660-16665 (2006).

  33. Mohraz, A. and M.J. Solomon, “Gelation and internal dynamics of colloidal rod aggregates,” Journal Colloid Interface Science 300(1) 155-162 (2006).

  34. Lee, M., M. Alcoutlabi, J.J. Magda, C. Dibble, M.J. Solomon, X.F. Shi and G.B. McKenna, “The shear-thickening transition of model colloidal spheres and its effect on the radial pressure profile during cone-and-plate and parallel plate shearing flows,” Journal of Rheology 50(3) 293-312 (2006).

  35. Solomon, T. and M.J. Solomon, “Stacking fault structure in shear-induced colloidal crystallization,” Journal of Chemical Physics, 124 art no. 134905 (2006).

  36. Mohraz, A. and M.J. Solomon, “Direct visualization of colloidal rod assembly by confocal microscopy,” Langmuir 21(12) 5298-5306 (2005).

  37. Vanapalli, S.A, M. Islam, M.J. Solomon, “Scission-induced bounds on maximum polymer drag reduction in turbulent flow,” Physics of Fluids, 17 art no. 095108 (2005).

  38. Wu, K.C., K.F. Seefeldt, M.J. Solomon and J.W. Halloran, “Prediction of ceramic stereolithograpy resin sensitivity from theory and measurement of diffuse photon transport,” Journal of Applied Physics, 98 art no. 024902 (2005).

  39. Glotzer, S.C., M.J. Solomon and N. Kotov, “Self-assembly: from nanoscale to microscale colloids,” AIChE Journal, 50(12) 2978-2985 (2004).

  40. Vermant, J. and M.J. Solomon, “Flow induced structure in colloidal suspensions,” Journal of Physics: Condensed Matter. 17 R187-R216 (2005).

  41. Mohraz, A. and M.J. Solomon, “Orientation and rupture of fractal colloidal gels during start-up of steady shear flow,” Journal of Rheology 49(3) 657-681 (2005).

  42. Solomon, M.J. and M. Kogan, “Confocal Optical Microscopy,” in Encyclopedia of Condensed Matter Physics, G. Bassani, G. Liedl and P. Wyder, (eds). Elsevier 229-235 (2005).

  43. Kim, K. M.T. Islam, X. Shen, A.I. Sirviente and M.J. Solomon, “Effect of macromolecular polymer structures on drag reduction in a turbulent channel flow,” Physics of Fluids 16(11) 4150-4162 (2004).

  44. Mohraz, A. D.B. Moler, R.F. Ziff and M.J. Solomon, “Effect of monomer geometry on the fractal structure of colloidal rod aggregates,” Physical Review Letters 92(15) 155503 1-4 (2004).

  45. Solomon, M.J. and A. Somwangthanaroj, “Intercalated polypropylene nanocomposites,” Dekker Encyclopedia of Nanoscience and Nanotechnology, edited by J.A. Schwarz, I. Contescu and K. Putyer, Marcel Dekker, 1483-1490 (2004).

  46. Almusallam, A.S., R.G. Larson and M.J. Solomon, “A comprehensive constitutive model for immiscible blends of Newtonian polymers,” Journal of Rheology, 48(2) 319-348 (2004).

  47. Islam, M, S.A. Vanapalli and MJ. Solomon, “Inertial Effects on Polymer Chain Scission in Planar Elongational Cross-Slot Flow,” Macromolecules, 37(3) 1023-1030 (2004).

  48. Varadan, P. and M.J. Solomon, “Direct visualization of flow-induced microstructure in dense colloidal gels by confocal laser scanning microscopy,” Journal of Rheology 47(4) 943-968 (2003).

  49. Almusallam, A.S., R.G. Larson and M.J. Solomon, “A constitutive model for breakup of extended droplets,” Journal of Non-Newtonian Fluid Mechanics 113(1) 29-48 (2003).

  50. Seefeldt, K.F. and M.J. Solomon, “Self-diffusion in dilute colloidal suspensions with attractive potential interactions,” Physical Review E 67, 050402(R) 1-4 (2003).

  51. Somwangthanaroj, A., E.C. Lee and M.J. Solomon, “Early stage quiescent and flow-induced crystallization of intercalated polypropylene nanocomposites by depolarized light scattering,” Macromolecules 36 2333-2342 (2003).

  52. Lerdwijitjarud, W., R.G. Larson, A. Sirivat and M.J. Solomon, “Influence of Weak Elasticity of Dispersed Phase on Droplet Behavior for Polybutadiene/Poly(dimethyl siloxane) Blends,” Journal of Rheology. 47(1) 37-58 (2003).

  53. Varadan, P. and M.J. Solomon, “Direct visualization of long-range heterogeneous structure in dense colloidal gels,” Langmuir 19(3) 509-512 (2003).

  54. Lu, Q. and M.J. Solomon, “Probe size effects on the microrheology of associating polymer solutions,” Physical Review E 66 061504-1 - 061504-11 (2002).

  55. Solomon, M.J. and Q. Lu, “Rheology and dynamics of particles in viscoelastic media,” Current Opinion in Colloid and Interface Science 6(5) 430-437 (2001).

  56. Varadan, P. and M.J. Solomon, “Shear-Induced Microstructural Evolution of a Thermoreversible Gel,” Langmuir 17 2918-2929 (2001).

  57. Solomon, M.J., A.S. Almusallam, K.F. Seefeldt, A. Somwangthanaroj and P. Varadan, “Rheology of Polypropylene/Clay Hybrid Materials”, Macromolecules 34(6) 1864-1872 (2001).

  58. Solomon, M.J. and P. Varadan, “Dynamic structure of thermoreversible colloidal gels of adhesive spheres,” Phys. Rev. E 63 051402-1 - 051402-10 (2001).

  59. Almusallam, A.S., R.G. Larson and M.J. Solomon, “A constrained volume model for the prediction of droplet shapes and stresses in immiscible blends,” J. Rheology 44(5) 1055-1083 (2000).

  60. Solomon, M.J., T. Saeki, M. Wan, P.J. Scales, D.V. Boger and H. Usui, "The Effect of Adsorbed Surfactants on the Rheology of Colloidal Zirconia Suspensions," Langmuir 15(1) 20-26 (1999).

  61. Zhou, Z., M.J. Solomon, P.J. Scales and D.V. Boger, “The yield stress of concentrated flocculated suspensions of size distributed particles,” J. Rheology 43(3) 651-672 (1999).

  62. Solomon, M.J. and D.V. Boger, "The rheology of aqueous dispersions of spindle-type colloidal hematite rods," J. Rheology 42(4), 929-949 (1998).

  63. Boger, D.V. and M.J. Solomon, "Newtonian Elastic Liquids – A Paradox!," in Theoretical and Applied Mechanics 1996, (eds. T. Tatsumi, E. Watanabe and T. Kambe) Elsevier Science, Amsterdam, 139-154 (1997).

  64. Lee, E.C., M.J. Solomon and S.J. Muller, "Molecular Orientation and Deformation of Polymer Solutions Under Shear: A Flow Light Scattering Study," Macromolecules, 30 7313-21 (1997).

  65. Solomon, M.J. and Muller, S.J. "Study of mixed solvent quality in a polystyrene - dioctyl phthalate - polystyrene system." Journal of Polymer Science: B, Polymer Physics, 34, 181-192 (1996).

  66. Solomon, M.J. and Muller, S.J. "Flow past a sphere in polystyrene-based Boger fluids: the effect on the drag coefficient of finite extensibility, solvent quality and polymer molecular weight," Journal of Non-Newtonian Fluid Mechanics, 62, 81-94 (1996).

  67. Solomon, M.J. and Muller. S.J. "The transient extensional behavior of polystyrene-based Boger fluids of varying solvent quality and molecular weight," J. Rheology, 40(5) 837-856 (1996).

Courses Taught

Currently, Solomon teaches the junior-level separation course (ChE 343). Previous electives Professor Solomon has offered are Polymer Science and Engineering (ChE 472), Molecular Engineering (ChE 496, with Mark Burns), Scattering and Optical Methods for Complex Fluids (ChE 696) as well as Nano and Colloidal Assembly (ChE 696). He also created the department's new one-credit course in ChE process economics (ChE 485).  Previously, Solomon taught the introductory material and energy balance course (ChE 230), undergraduate fluid mechanics (ChE 341), the junior chemical engineering laboratory (ChE 360) and graduate fluid dynamics (ChE 527).