Deswelling of Poly(N-isopropylacrylamide) derived hydrogels and their nanocomposites with iron oxide nanoparticles as revealed by X-ray photon correlation spectroscopy

Here we present results on the deswelling behavior of semi-interpenetrating polymer hydrogels of sodium alginate and poly(N-isopropylacrylamide) (PNI-PAAm) containing iron oxide nanoparticles by means of Xray photon correlation spectroscopy (XPCS). The experiments were carried out as a function of t...

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Detalles Bibliográficos
Autores: Hernández, Rebeca, Criado-González, Miryam, Nogales, Aurora, Sprung, Michael, Mijangos, Carmen, Ezquerra, Tiberio A.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/111479
Acceso en línea:http://hdl.handle.net/10261/111479
Access Level:acceso abierto
Palabra clave:ddc:540
Descripción
Sumario:Here we present results on the deswelling behavior of semi-interpenetrating polymer hydrogels of sodium alginate and poly(N-isopropylacrylamide) (PNI-PAAm) containing iron oxide nanoparticles by means of Xray photon correlation spectroscopy (XPCS). The experiments were carried out as a function of temperature starting from temperatures below the low critical solution temperature (LCST) of the materials to temperatures above their LCST. The hydrogels present a hyper-diffusive dynamics of similar nature as that found for the freeze-dried aerogels which has been attributed to their characteristic porous structure. The dynamics of the swollen samples is faster than that of the freeze-dried ones suggesting that water has an effect in accelerating the dynamics of the hydrogels. XPCS has been used to characterize the deswelling process as a function of temperature. Deswelling times for the different samples correlate well with the corresponding relaxation times of the relaxation processes measured by XPCS. (Graph Presented)