Probing in-situ the molecular dynamics of gas-poly(1-trimethylsilyl-1-propyne) (polyTMSP) systems with dielectric and NMR spectroscopies
The molecular dynamics of poly(1-trimethylsilyl-1-propyne) in the presence of N, CO, CH and CH, is assessed in situ with broadband dielectric and solid state NMR spectroscopies. The measurements of the dielectric permittivity and the analysis of the dielectric spectra show two secondary β relaxation...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/347844 |
| Acceso en línea: | http://hdl.handle.net/10261/347844 |
| Access Level: | acceso abierto |
| Palabra clave: | Gas separation Glassy polymers High free volume fraction Broadband dielectric spectroscopy Solid state NMR spectroscopy |
| Sumario: | The molecular dynamics of poly(1-trimethylsilyl-1-propyne) in the presence of N, CO, CH and CH, is assessed in situ with broadband dielectric and solid state NMR spectroscopies. The measurements of the dielectric permittivity and the analysis of the dielectric spectra show two secondary β relaxations and the absence of a glass transition. These relaxations could be associated to highly flexible and disordered regions (β), and to more rigid and ordered ones (β). The E of β observed in the presence of CO was the highest among the four gases studied, suggesting an increased presence in disordered regions. The results of C T NMR relaxation measurements provide complementary information on the polymer backbone dynamics. The Ts of main chain carbons increase as the concentration of gas sorbed in the polymer increases, indicative of a decrease in chain mobility. The combination of both spectroscopies afforded additional insight toward the understanding of gas transport in glassy microporous polymers. |
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