A5017844298- Rheology and Fluid Dynamics Studies
- Polymer crystallization and properties
- Polymer Foaming and Composites
- Polymer Nanocomposites and Properties
- Marine and Offshore Engineering Studies
- Problem and Project Based Learning
- Spacecraft and Cryogenic Technologies
- Experimental Learning in Engineering
- Fluid Dynamics Simulations and Interactions
- Innovative Teaching Methods
University of Michigan
2016-2019
We compare predictions of two the most advanced versions tube model, namely "Hierarchical model" by Wang et al. [J. Rheol. 2010, 54, 223] and BoB (branch-on-branch) model Das 2006, 50, 207], against linear viscoelastic G′ G″ data binary blends nearly monodisperse 1,4-polybutadiene 4-arm star polymer arm molar mass 24 000 g/mol with a 58 g/mol. The was carefully synthesized characterized temperature gradient interaction chromatography rheology over wide frequency region through...
Despite the prevalence of polymers in modern everyday life, there is little introduction to topic science education throughout primary or secondary schooling United States. Of few states that do include polymer education, this only found at high school level, primarily biology chemistry. Over past year, we have developed a graduate-student-run outreach initiative aimed providing young students with an understanding and appreciation class materials through interactive teaching...
We determine experimentally the "dilution exponent" α for entangled polymers from scaling of terminal crossover frequency with entanglement density linear rheology three 1,4-polybutadiene star that are blended low-molecular-weight, unentangled at various volume fractions, ϕs. Assuming monodisperse stars depends solely on plateau modulus GN(ϕs) ∝ ϕs1+α, number entanglements per chain Me(ϕs) ϕs–α, and tube-segment frictional Rouse time τe(ϕs) ϕs–2α, we show only an = 1 superposes dependence...
We blend newly synthesized nearly monodisperse four-arm star 1,4-polybutadienes with various well-entangled linear polymers, confirming the conclusions in Desai et al. [ Macromolecules201649 (13)49644977] that advanced tube models, namely, hierarchical 3.0 and branch-on-branch models [Wang, Z.; J. Rheol.201054 (2)223260], fail to predict rheological data when pure polymers have shorter relaxation times, but within 3–4 orders of magnitude polymer. However, polymer has a longer time than star,...