Microrheology of cross-linked polyacrylamide networks

@article{citeulike:2710294, abstract = {Experiments investigating the local viscoelastic properties of a chemically cross-linked polymer are performed on polyacrylamide solutions in the sol and the gel regimes using polystyrene beads of varying sizes and surface chemistry as probes. The thermal motions of the probes are measured to obtain the elastic and viscous moduli of the sample. Probe dynamics are measured using two different dynamic light scattering techniques, diffusing wave spectroscopy (DWS) and quasielastic light scattering (QELS) as well as video-based particle tracking. Diffusing wave spectroscopy probes the short-time dynamics of the scatterers while QELS measures the dynamics at larger times. Video-based particle tracking provides a way to investigate the local environment of the individual probe particles. A combination of all the techniques results in a larger range of frequencies that can be probed compared to conventional bulk measurements while providing local information at the level of individual probes. A modified algebraic form of the generalized Stokes-Einstein equation is used to calculate the frequency-dependent moduli. A comparison of microrheological measurements with bulk rheology exhibits striking similarity, confirming the applicability of microrheology for chemically cross-linked polymeric systems.}, author = {Dasgupta, Bivash R. and Weitz, D. A. }, citeulike-article-id = {2710294}, doi = {10.1103/PhysRevE.71.021504}, journal = {Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)}, keywords = {microrheology, polymer, weitz}, number = {2}, posted-at = {2008-04-23 22:44:34}, priority = {2}, publisher = {APS}, title = {Microrheology of cross-linked polyacrylamide networks}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=PLEEE8000071000002021504000001\&idtype=cvips\&gifs=yes}, volume = {71}, year = {2005} }

TY - JOUR ID - citeulike:2710294 L3 - citeulike-article-id:2710294 TI - Microrheology of cross-linked polyacrylamide networks JF - Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) VL - 71 IS - 2 PB - APS N2 - Experiments investigating the local viscoelastic properties of a chemically cross-linked polymer are performed on polyacrylamide solutions in the sol and the gel regimes using polystyrene beads of varying sizes and surface chemistry as probes. The thermal motions of the probes are measured to obtain the elastic and viscous moduli of the sample. Probe dynamics are measured using two different dynamic light scattering techniques, diffusing wave spectroscopy (DWS) and quasielastic light scattering (QELS) as well as video-based particle tracking. Diffusing wave spectroscopy probes the short-time dynamics of the scatterers while QELS measures the dynamics at larger times. Video-based particle tracking provides a way to investigate the local environment of the individual probe particles. A combination of all the techniques results in a larger range of frequencies that can be probed compared to conventional bulk measurements while providing local information at the level of individual probes. A modified algebraic form of the generalized Stokes-Einstein equation is used to calculate the frequency-dependent moduli. A comparison of microrheological measurements with bulk rheology exhibits striking similarity, confirming the applicability of microrheology for chemically cross-linked polymeric systems. KW - microrheology KW - polymer KW - weitz AU - Dasgupta, Bivash AU - Weitz, DA PY - 2005/// UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PLEEE8000071000002021504000001&idtype=cvips&gifs=yes ER -