Speaker:
Arjun Yodh
Institution:
Univ. of Pennsylvania
Speaker Link:
Date:
Thursday, October 29, 2015
Time:
3:30 pm
Location:
RH 101
ABSTRACT:
Soft matter experiments that explore fundamental issues about ordered and disordered materials in condensed matter physics will be discussed. Recent work employs a novel class of colloidal suspension composed of temperature-sensitive hydrogel particles; the temperature “knob” permits easy control of particle packing and simultaneous viewing by video microscopy [1]. These features, in turn, enable us to use colloidal crystals to answer open questions about “how and where” crystal melting begins and about the mechanisms by which one crystal transforms to another during a solid-solid phase transition [2]. These features have also enabled us to critically explore questions about disordered solids, e.g., how glasses rearrange internally when responding to mechanical stress [3]. After a broad introduction about soft matter and colloidal suspensions, I will describe these new experiments.
REFERENCES
[1] Yunker, P.J., Chen, K., Gratale, M.D., Lohr, M.A., Still, T., Yodh, A.G., Reports on Progress in Physics 77, 056601 (2014).
[2] A.M. Alsayed, M.F. Islam, J. Zhang, P.J. Collings, A.G. Yodh, Science 309, 1207-1210 (2005); Y. Han, Y. Shokef, A. Alsayed, P. Yunker, T. C. Lubensky, A. G. Yodh, Nature 456, 898-903 (2008); Peng, Y., Wang, F., Wang, Z., Alsayed, A.M., Zhang, Z., Yodh, A.G., and Han, Y., Nature Materials Nature Materials 14, 101-108, (2015).
[3] Chen, K., Ellenbroek, W.G., Zhang, Z.X., Chen, D.T.N., Yunker, P.J., Henkes, S., Brito, C., Dauchot, O., van Saarloos, W.,
Liu, A.J., and Yodh, A.G., Phys. Rev. Lett. 105, 025501 (2010); Chen, K., Manning, M.L., Yunker, P.J., Ellenbroek, W.G., Zhang, Z., Liu, A.J., and Yodh, A.G., Phys. Rev. Lett. 107, 108301 (2011); Still, T., Goodrich. C.P., Chen, K., Yunker, P.J., Schoenholz, S., Liu, A.J., and Yodh, A.G., Phys. Rev. E 89, (2014).
Host:
Peter Taborek