Complex dynamics of capillary imbibition of poly(ethylene oxide) melts in nanoporous alumina
| Autor: | Stelios Alexandris, Hans-Jürgen Butt, Franziska Henrich, George Floudas, Yang Yao, Martin Steinhart, Günter K. Auernhammer |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Materials science Ethylene oxide Capillary action Nanoporous Oxide General Physics and Astronomy Thermodynamics 02 engineering and technology Polymer Penetration (firestop) 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Nanopore chemistry Polymer chemistry Imbibition Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | The Journal of chemical physics. 146(20) |
| ISSN: | 1089-7690 |
| Popis: | Capillary penetration of a series of entangled poly(ethylene oxide) melts within nanopores of self-ordered alumina follows an approximate t1/2 behavior according to the Lucas-Washburn equation; t is the time. However, the dependence on the capillary diameter deviates from the predicted proportionality to d1/2; d is the pore diameter. We observed a reversal in the dynamics of capillary rise with polymer molecular weight. Chains with 50 entanglements (Mw ≤ 100 kg/mol) or less show a slower capillary rise than theoretically predicted as opposed to chains with more entanglements (Mw ≥ 500 kg/mol) that display a faster capillary rise. Although a faster capillary rise has been predicted by theory and observed experimentally, it is the first time to our knowledge that a slower capillary rise is observed for an entangled polymer melt under conditions of strong confinement (with 2Rg/d = 1). These results are discussed in the light of theoretical predictions for the existence of a critical length scale that depends on the molecular weight and separates the microscopic (d d*) regime. |
| Databáze: | OpenAIRE |
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