image_Tim_Still
Dr. Tim Still

Postdoc

Laboratory for Research on
the Structure of Matter (LRSM)
University of Pennsylvania
3231 Walnut Street
Philadelphia, PA 19104-6396
phone: (+01) 215 573 4080
email: timstill "at" seas.upenn.edu

 _____________________________

Dr. rer. nat. (Ph.D.), Max Planck Institute for Polymer
    Research, Gutenberg University Mainz, 2009
(AK Butt)

Dipl. Chem. , Philipps-Univ. Marburg, 2007 (AK Pilgrim)


working fields:
soft matter physics, colloidal glasses, hydrogel systems,
drop evaporation, carbon nanotubes, polymers,
Brillouin light scattering on colloidal and non-colloidal samples,
Phononics, nano- and mesoacoustic properties of soft condensed matter




Publications

2014

[24] P. J. Yunker, Ke Chen, M. D. Gratale, M. A. Lohr, T. Still, A. G. Yodh, Rep. Prog. Phys. 2014, 77, 056601. 
    Physics in ordered and disordered colloidal matter composed of poly(N-isopropyl acrylamide) microgel particles

[23] A. Basu, Ye Xu, T. Still, P. E. Arratia, Zexin Zhang, K. N. Nordstrom, J. M. Rieser, J. P. Gollub, D. J. Durian, A. G. Yodh, Soft Matter 2014, 10, 3027.  
    Rheology of soft colloids across the onset of rigidity: scaling behavior, thermal, and non-thermal responses

[22] T. Still, C. P. Goodrich, Ke Chen, P. J. Yunker, S. Schoenholz, A. J. Liu, A. G. Yodh
Physical Review E 2014, 89, 012301 (arXiv: 1306.3188).
    Phonon dispersion and elastic moduli of two-dimensional disordered colloidal packings of soft particles with frictional interactions

2013

[21] T. Still, M. Oudich, G. K. Auernhammer, D. Vlassopoulos, B. Djafari-Rhouani, G. Fytas, P. Sheng, Physical Review B 2013, 88, 094102.
    Soft silicone rubber in phononic structures: Correct elastic moduli

[20] Ke Chen, T. Still, S. Schoenholz, K. B. Aptowicz, M. Schindler, A. C. Maggs, A. Liu, A. G. Yodh, Physical Review E 2013, 88, 022315.
    
Phonons in two-dimensional soft colloidal crystals

[19] M. D. Gratale, P. J. Yunker, K. Chen, T. Still, K. B. Aptowicz, A. G. Yodh, Physical Review E 2013, 87, 052301.
    Phonons in two-dimensional colloidal crystals with bond-strength disorder

[18] T. Still, Ke Chen, A. M. Alsayed, K. B. Aptowicz, A. G. Yodh, Journal of Colloid and Interface Sciences 2013, 405, 96.
    Synthesis of micrometer-size poly(N-isopropylacrylamide) microgel particles with homogeneous crosslinker density and diameter control

[17]
P. J. Yunker, T. Still, A. G. Yodh, Proceedings of the International School of Physics "Enrico Fermi" Course CLXXXIV "Physics of Complex Colloids" 2013; arXiv: 1308.1874.
    Colloidal Shape Effects in Evaporating Drops

[16] P. J. Yunker, M. A. Lohr, T. Still, A. Borodin, D. J. Durian, A. G. Yodh, Physical Review Letters 2013, 110
, 035501.
    
Effects of Particle Shape on Growth Dynamics at Edges of Evaporating Drops of Colloidal Suspensions

2012

[15] P. J. Yunker, M. Gratale, M. A. Lohr, T. Still, T. C. Lubensky, A. G. Yodh, Physical Review Letters 2012, 108228303
    Influence of particle shape on bending rigidity of colloidal monolayer membranes and particle deposition during droplet evaporation in confined geometries

[14] T. Still, P. J. Yunker, A. G. Yodh, Langmuir 2012,
28, 4984.
     Surfactant-Induced Marangoni Eddies Alter the Coffee-Rings of Evaporating Colloidal Drops
   
    
[13] M. Mattarelli, M. Montagna, T. Still, D. Schneider, G. Fytas, Soft Matter
2012, 8, 4235.
    Vibration spectroscopy of weakly interacting mesoscopic colloids

2011

[12] P. J. Yunker, T. Still, M. A. Lohr, A. G. Yodh, Nature 2011, 476, 308.
     Suppression of the coffee-ring effect by shape-dependent capillary interactions
   
  (with `News & Viewsʹ by J. Vermant, Nature 2011, 476, 286 and cover page;
        highlighted in international
press, e.g., Le Monde (France), Sueddeutsche Zeitung, Welt (Germany), ORF (Austria),
        NPR [radio], MSNBC, Discover Magazin, ABC, International Business Times, New Scientist etc. (USA))

   
[11] T. Still, G. Gantzounis, D. Kiefer, G. Hellmann, G. Fytas, N. Stefanou, Physical Review
Letters 2011, 106, 175505.
    Collective Hypersonic Excitations in Strongly Multiple Scattering Colloids

[10] Z. Fakhraai, T. Still (equal contribution), G. Fytas, M. D. Ediger ,
Journal of Physical Chemistry Letters 2011, 2, 423.
    Structural Variations of an Organic Glassformer Vapor-Deposited onto a Temperature Gradient Stage

2010

[9] T. Still*, M. Mattarelli, D. Kiefer, G. Fytas, M. Montagna, Journal of Physical Chemistry Letters 2010, 1, 2440.
    Eigenvibrations of Submicrometer Colloidal Spheres

[8] F. Stadler, T. Still, G. Fytas, C. Bailly, Macromolecules 2010, 43, 7771.
    Elongational Rheology and Brillouin Light Scattering of Entangled Telechelic Polybutadiene Based Temporary Networks

[7] T. Still*, M. Retsch, U. Jonas, R. Sainidou, P. Rembert, K. Mpoukouvalas, G. Fytas, Macromolecules 2010, 43, 3422.
    Vibrational Eigenfrequencies and Mechanical Properties of Mesoscopic Copolymer Latex Particles

[6] K. L. Kearns, T. Still (equal contribution), G. Fytas, M. D. Ediger, Advanced Materials 2010, 22, 39.
    High-Modulus Organic Glasses Prepared by Physical Vapor Deposition

2009

[5]  T. Still, High frequency acoustics in colloid-based meso- and nanostructures by spontaneous Brillouin light scattering , PhD thesis, Johannes Gutenberg-Universität Mainz. (printed by Springer (2010),  ISBN: 978-3-642-13482-1)

[4] T. Still*, M. D'Acunzi, D. Vollmer, G. Fytas,
Journal of Colloid and Interface Sciences 2009, 340, 42.
    Mesospheres in nano-armor: Probing the shape-persistence of molten polymer colloids

2008

[3] T. Still, R. Sainidou, M. Retsch, U. Jonas, P. Spahn, G. P. Hellmann, G. Fytas, Nano Letters 2008, 8, 3194.
    The Music of Core-Shell Spheres and Hollow Capsules: Influence of the Architecture on the Mechanical Properties at the Nanoscale
    
(with `Top down, Bottom upʹ in Nature Nanotechnology 2008, 3, 641)

[2] T. Still, W. Cheng, M. Retsch, U. Jonas, G. Fytas, Journal of Physics: Condensed Matter 2008, 20, 404203.
    Colloidal systems: a promising material class for tailoring sound propagation at high frequencies

[1] T. Still, W. Cheng, M. Retsch, R. Sainidou, J. Wang, U. Jonas, N. Stefanou, G. Fytas, Physical Review Letters 2008, 100, 194301.
    Simultaneous Occurrence of Structure-Directed and Particle-Resonance-Induced Phononic Gaps in Colloidal Films

2007

T. Still, Inelastische Neutronenstreuung an geschmolzenen Natriumhaliden, Diploma thesis, Philipps-Universität Marburg.


Presentations on international conferences

2014

ACS 2014 Colloid & Surface Science Symposium, Philadelphia, PA, USA, 06/22-25/2014:
T. Still, K. Chen, C.P. Goodrich, S. Schoenholz, A.C. Maggs, A.J. Liu, A.G. Yodh (oral Presentation):
Phonons in quasi-two-dimensional soft colloidal glasses and crystals

APS March meeting, Denver, CO, USA, 03/03-07/2014:
T. Still, P. J. Yunker, A. G. Yodh (oral Presentation):
Mechanical response of a colloidal glass undergoing repeated local perturbation

Mid-Atlantic Soft Matter Workshop (MASM 12), Philadelphia, PA, USA, 01/17/2014:
T. Still (sound bite):
Phonons in Soft Colloidal Glasses with Frictional Interactions


2013

Symposium "Evolution of Colloidal Matter", New York, NY, USA, 06/27-29/2013:
T. Still, C. P. Goodrich, Ke Chen, P. J. Yunker, S. Schoenholz, A. J. Liu, A. G. Yodh (Poster).
Phonon Dispersion and Elastic Moduli of Two-Dimensional Disordered Colloidal Packings of Soft-Particles with Frictional Interactions

APS March meeting, Baltimore, MD, USA, 03/18-22/2013
:

T. StillC. P. Goodrich, Ke Chen, P. J. Yunker, S. Schoenholz, A. J. Liu, A. G. Yodh (oral Presentation):
Phonon Dispersion and Elastic Properties of Two-Dimensional Soft Particle Colloidal Crystals and Glasses

TAFDV Symposium, West Conshohocken, PA, USA, 03/14/2013:
T. Still (oral Presentation, invited):
The coffee ring effect


Workshop "Soft Matter at Interfaces 2013", Schloss Ringberg, Germany, 03/03-06/2013:
T. Still (oral Presentation, invited):
New twists on the coffee ring effect



2012

244th ACS National Meeting, Philadelphia, PA, USA, 08/19-23/2012:
T. Still, Ke Chen, P. J. Yunker, K. Aptowicz, A. G. Yodh (oral Presentation):
Local Perturbation of Quasi-2D Soft Colloidal Glasses

Mid-Atlantic Soft Matter Workshop (MASM 9), U Maryland, College Park, MD, USA, 07/20/2012:
T. Still (sound bite):
Elastic Properties of Quasi-Two-Dimensional Colloidal Model Systems

APS March meeting, Boston, MA, USA, 02/27-03/02/2012:
T. Still, P. J. Yunker, A. G. Yodh (oral Presentation):
Particle Deposition in Drying Drops of Colloidal Suspensions Containing Different Surfactants
K. Aptowicz, T. Still, Ke Chen, P. J. Yunker, A. G. Yodh (oral Presentation):
Local Perturbation of Quasi Two-Dimensional Colloidal Glasses



2011

6th Gotham-Metro Condensed Matter Meeting, New York, NY, USA, 11/11/2011:
T. Still , Ke Chen, P. J. Yunker, K. Aptowicz, A. G. Yodh (Poster):
Local Perturbation in Quasi-Two-Dimensional Colloidal Glasses

Mid-Atlantic Soft Matter Workshop (MASM 7), Philadelphia, PA, USA, 06/10/2011
:

T. Still (sound bite):
The Influence of Surfactants on the Coffee-Ring Effect in Drying Colloidal Suspensions

APS March meeting, Dallas, TX, USA, 03/21-25/2011
:

T. Still, G. Fytas, M. Mattarelli, M. Montagna (oral Presentation):
Colloidal Particle Vibration Spectroscopy


2010

Son et lumière 2010, Cargèse, Corse, France, 08/30-09/11/2010:
T. Still, G. Fytas (oral Presentation + Poster):
Hypersonic Colloidal Phononics

International Soft Matter Conference 2010, Granada, Spain, 07/05-08/2010:
T. Still, G. Fytas (oral Presentation, invited):
Hypersonic Phononics


2009

ICPPP 15, Leuven, Belgium, 07/19-23/2009:
T. Still, A. Sato, G. Fytas (oral Presentation):
Tailoring Phonon Propagation by Mesoscopic Engineering of Soft Matter

APS March meeting, Pittsburgh, PA, USA, 03/16-20/2009
:
T. Still, R. Sainidou, G. Hellmann, G. Fytas (oral presentation):
The “Music” of Silica-Poly(methyl methacrylate) Core-Shell Spheres: Eigenvibrations and Mechanical Properties at the Nanoscale 
K. L. Kearns, T. Still, G. Fytas, M. D. Ediger (Poster):
Brillouin light scattering measurements of high modulus glasses produced by physical vapor deposition

Makromolekulares Kolloquium 2009, Freiburg, Germany, 02/26-28/2009:
M. Retsch, T. Still, W. Cheng, R. Sainidou, U. Jonas, N. Stefanou, G. Fytas (Poster):
Phononic Properties of Colloidal Particles and Nanostructured Films


2008


16th Ostwald Colloquium, Leipzig, Germany, 09/22-24/2008:
T. Still, M. Retsch, R. Sainidou, U. Jonas, G. Fytas (oral presentation):
High frequency acoustics in colloidal systems by spontaneous Brillouin light scattering

Son et lumière 2008, Cargèse, Corse, France, 09/01-13/2008:
T. Still, M. Retsch, R. Sainidou, W. Cheng, U. Jonas, G. Fytas (oral Presentation + Poster):
GHz acoustics in colloidal systems by spontaneous Brillouin light scattering

Acoustics'08, Paris, France, 06/29-07/04/2008:
T. Still, M. Retsch, R. Sainidou, U. Jonas, G. Fytas (oral presentation):
High frequency acoustics in colloidal systems by spontaneous Brillouin light scattering  (J. Acoust. Soc. Am. 2008, 123, 3555.)