Carnegie Mellon University

Stephen Garoff

Emeritus Professor of Physics
Professor of Chemical Engineering (Courtesy) and Professor of Materials Science & Engineering (Courtesy)

Soft Condensed Matter / Biological Physics Experiment
Wean Hall 6313

lab website

Prof. Steve Garoff

Education & Professional Experience

Ph.D.: Harvard University, Applied Physics (1977)
M.S.: Harvard University, Applied Physics (1974)
B.S.: Yale University (1972)

Professional Societies:
American Physical Society, American Chemical Society, Materials Research Society
Fellow, American Physical Society

Curriculum Vitae

Head, Physics Department, Carnegie Mellon University, 2013–17
Professor of Physics, Carnegie Mellon University, 1988–
Professor of Chemical Engineering (Courtesy), Carnegie Mellon University, 1988–
Professor of Materials Science & Engineering (Courtesy), Carnegie Mellon University, 1988–
Research Scientist: Schlumberger-Doll Research, Ridgefield, CT, 1986–88
Research Scientist: Exxon Research, Annandale, NJ, 1977–86

Research Interests

The properties of interfacial regions where fluid or solid phases meet dominate the behavior of many natural and technical processes. Wetting, friction and adhesion, corrosion, stability of emulsions (droplets of liquids in another liquid) or colloidal suspensions (solid particles suspended in a liquid) are some examples. But attaining a fundamental understanding of their behavior challenges our experimental abilities because these interfacial regions are structurally complex on a molecular scale, are seldom homogeneous on a microscopic scale, and may not even be in equilibrium. Often monomolecular layers along the interfaces dominate the behavior of the interface and the macroscopic phenomenon. In the Interfacial Physics Group we attempt to build an understanding of interfacial phenomena on the molecular, microscopic, and macroscopic levels. In our research, we probe many different liquid systems, including aqueous and non-aqueous fluids and solutions, surfactants and polymers, and even metals interacting with a variety of solids, including glasses, oxides and metals. We employ a range of techniques including x-ray, neutron, and optical techniques, atomic force microscopy, rheology, as well as UHV and non-UHV materials preparation. Presently, we focus on wetting, friction, and colloidal forces. Our program draws on a broad range of scientific phenomena such as random field effects, nonequilibrium states, hydrodynamics, and noise in hysteretic systems. The results of our research reveal the scientific underpinnings of such technologies as coatings, adhesion, colloidal stability, and multiphase fluid flow.

We maintain extensive collaborations with groups in the Material Science, Chemical Engineering an Biomedical Engineering Departments at Carnegie Mellon as well as in the University of Pittsburgh Medical School. We participate in the programs of the Center for Complex Fluids Engineering. We also work on applications of our research through projects funded by industry. For more details on our group, see Interfacial Physics Group.

Selected Publications

S Iasella, R Sharma, S Garoff, RD Tilton, Interaction of Impinging Marangoni Fields, J. Colloid Interface Sci., 653, 807-820 (2024)

A Yang, B McKenzie, Y Yi, S Garoff, R Tilton, Effect of Polymer/Surfactant Complexion on Diffusiophoresis of Colloids in Surfactant Concentration Gradients, J. Colloid Interface Sci., 642, 169-181 (2023)

VT Gurumurthy, M Baumhauer, A Khair, IV Roisman, C Tropea, S Garoff, Phys. Rev. Fluids, 7, 114002 (2022)

H. Chu, S. Garoff, A. Khair, R.D. Tilton,  Tuning Chemotactic and Diffusiophoretic Spreading via Hydrodynamic Flows,  Soft Matter, 18, 1896 - 1910 (2022)

 S. Garoff,  T-L Hsieh, W Xu,ML. Sauleda, RD. Tilton,  Surfactant Spreading on a Deep Subphase: Coupling of Marangoni Flow and Capillary Waves,   J. Coll. & Interf. Sci. (2022)

T. Hsieh, S. Garoff, S. Law, R. Tilton,  pH-Dependent Interfacial Tension and Dilatational Modulus Synergism of Oil-Soluble Fatty Acid and Water-Soluble Cationic Surfactants at the Oil/Water Interface, Langmuir, 37, 11573-11581 (2021) 

T. Corcoran, S. Garoff,  Effect of a Surfactant Additive on Drug Transport and Distribution Uniformity After Aerosol Delivery to ex vivo Lungs J Aerosol Med Pulm Drug Deliv., (2021)

HCW. Chu, S. Garoff, A. Khair, RD. Tilton,  Macrotransport Theory for Diffusiophoretic Colloids and Chemotactic Microorganisms J. Fluid Mech. 917 , A52; PII S0022112021003220 (2021)

HCW. Chu, S. Garoff, ML. Sauleda, RD. Tilton,  Surfactant Driven Marangoni Spreading in the Presence of Predeposited Insoluble Surfactant Monolayers, Langmuir, 37, 3309-3320 (2021)

J. Coll.; T-L Hsieh;S. Garoff; MR. Martinez; K. Matyjaszewski, R.Tilton., Interfacial Dilatational Rheology as a Bridge to Connect Amphiphilic Heterografted Bottlebrush Copolymer Architecture to Emulsifying EfficiencyInterf. Sci, 581, 135-147 (2021)

Henry C.W. Chu et al., Advective-diffusive Spreading of Diffusiophoretic Colloids under Transient Solute Gradients, Soft Matter 16, 238 (2020)

Henry C.W. Chu et al., Dispersion in Steady and Time-Oscillatory Flows Through an Eccentric Annulus, AIChE J., e16831 (2019)

Steven V. Iasella et al., Flow Regime Transitions and Effects on Solute Transport in Surfactant-Driven Marangoni Flows, J. Coll. & Interf. Sci. 553, 136 (2019)

Vignesh T. Gurumurthy et al., Spontaneous rise in open rectangular channels under gravity, J. Coll. Interf. Sci. 527, 151 (2018)

Amy Z. Stetten et al., Evolution and disappearance of solvent drops on miscible polymer subphases, Coll. Surf. A 546, 266 (2018)

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ORCID  Researcher ID