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Your search keyword '"THERMAL properties"' showing total 2 results
Start Over Descriptor "THERMAL properties" Topic chemical engineering Publication Year Range Last 50 years Publisher american chemical society
2 results on '"THERMAL properties"'

1. Significant Impact of Thermo-Mechanical Conditions on Polymer Triple-Shape Memory Effect.

Author

Junjun Li and Tao Xie

Subjects
*CHEMICAL engineering, *POLYMERS, *THERMAL properties, *MECHANICAL behavior of materials, *HEATING, *SHAPE memory effect, *MACROMOLECULES
Abstract

A polymer triple-shape memory effect represents one of the most recent discoveries in the rapidly expanding field of shape memory polymers. It refers to the capability of a polymer to memorize two temporary shapes and subsequently recover them, all in one shape memory cycle. Although several examples of triple-shape polymers had been reported in the literature, they were notably evaluated under very different thermo-mechanical conditions. In this study, the effect of various thermo-mechanical conditions on the polymer triple-shape properties was investigated using Nafion as a model material. The choice of the programming and recovery heating methods in constructing triple-shape cycles was found to have a profound impact on the triple-shape properties. As such, the results of this study provided useful reference for future development of triple-shape polymers. [ABSTRACT FROM AUTHOR]

Published
2011
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2. Development of Hierarchically Porous Ionomer Membranes for Versatile and Fast Metal Ion Conduction

Author

Christian Hänsel and Dipan Kundu

Subjects
Thermal properties, Materials science, Alkali metals, General Chemical Engineering, Materials Science, Mechanical properties, Solvation, Ether, 02 engineering and technology, 010402 general chemistry, Electrochemistry, 01 natural sciences, Article, Dissociation (chemistry), Ion, lcsh:Chemistry, Batteries, chemistry.chemical_compound, Polymer morphology, Distribution function, Analytical chemistry, Fuel cells, Inorganic chemistry, Polyethers, Porosity, Redox potential, Transport phenomena (Physical chem.), Ionomer, chemistry.chemical_classification, General Chemistry, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Sulfonate, Membrane, lcsh:QD1-999, chemistry, Chemical engineering, 0210 nano-technology
Abstract

Innovative design concepts can play a key role in the realization of high-performance ionomer membranes that are capable of exclusive metal ion conduction and potentially applicable in electrochemical devices including sensors, fuel cells, and high-energy batteries. Herein, we report on the development of new ionomers, based on sulfonated poly(ether ether ketone) (SPEEK), engineered to conduct a variety of ions, namely, Li+, Na+, K+, Zn2+, and Mg2+, when soaked with nonaqueous solvents. Application of a facile phase-inversion method results in M-SPEEK (M = Li/Na/K/Zn/Mg) membranes with a hierarchical porous network, facilitating organic solvent infusion that is necessary to promote dissociation and rapid transport of cations between anionic sulfonate groups on the polymer chains. This strategy leads to membranes with alkali ion conductivities approaching 10–4 S cm–1 at room temperature, and near unity cation transference numbers (tM+ ≥ 0.9). Furthermore, an exceptionally high Zn-ion conductivity of 10–2 S cm–1 is obtained for the water-infused Zn-SPEEK membrane. In comparison, the dense membranes demonstrate 2–3 orders of magnitude lower conductivities because of insufficient solvent infusion. Preliminary electrochemical studies with solvent-infused ionomer membranes as the electrolyte look promising., ACS Omega, 4 (2), ISSN:2470-1343

Published
2019

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