Glass transition and relaxation processes of nanocomposite polymer electrolytes.
J Phys Chem B
; 116(26): 7762-70, 2012 Jul 05.
Article
in En
| MEDLINE
| ID: mdl-22686254
ABSTRACT
This study focus on the effect of δ-Al(2)O(3) nanofillers on the dc-conductivity, glass transition, and dielectric relaxations in the polymer electrolyte (PEO)(4)LiClO(4). The results show that there are three dielectric relaxation processes, α, ß, and γ, in the systems, although the structural α-relaxation is hidden in the strong conductivity contribution and could therefore not be directly observed. However, by comparing an enhanced dc-conductivity, by approximately 2 orders of magnitude with 4 wt % δ-Al(2)O(3) added, with a decrease in calorimetric glass transition temperature, we are able to conclude that the dc-conductivity is directly coupled to the hidden α-relaxation, even in the presence of nanofillers (at least in the case of δ-Al(2)O(3) nanofillers at concentrations up to 4 wt %). This filler induced speeding up of the segmental polymer dynamics, i.e., the α-relaxation, can be explained by the nonattractive nature of the polymer-filler interactions, which enhance the "free volume" and mobility of polymer segments in the vicinity of filler surfaces.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Phys Chem B
Journal subject:
QUIMICA
Year:
2012
Document type:
Article
Affiliation country:
Suecia