Jump to Main Content
Nanoindentation of annealed Nafion/sulfonated graphene oxide nanocomposite membranes for the measurement of mechanical properties
- Lee, Sangmin, Choi, Bong Gill, Choi, Dukhyun, Park, Ho Seok
- Journal of membrane science 2014 v.451 pp. 40-45
- annealing, asymmetric membranes, graphene oxide, hardness, mechanical properties, nanocomposites, polymers
- The functionalized graphene oxides (GOs) are advanced nanofillers to improve the mechanical properties of the nanocomposite membranes, which can be further enhanced by a simple thermal annealing. Here, we report the preparation and annealing of Nafion/sulfonated GO (N/sG) nanocomposite membranes for the improvement of mechanical properties. In particular, the influence of thermal annealing on the mechanical behaviors of the N/sG composite membranes was investigated by the nanoindentation. The macro- and microscopically uniform dispersion of sGO in the polymer matrices arising from the favorable interactions between them could effectively improve the modulus of Nafion by up to 24.3% (from 0.70GPa to 0.87GPa at the loading of 1.0wt% of sGO) while preserving the hardness. Both the modulus and hardness of the composite membranes were further enhanced by ~27% (from 0.70GPa to 0.89GPa) and ~6.6% (from 62MPa to 65MPa), respectively, after the thermal annealing at 160°C. This annealing-induced improvement results from the reorientation of crystalline domain in the composite membranes. These findings provide a new insight to improve the mechanical behaviors of the nanocomposite membranes by means of the incorporation of the functionalized GOs and the treatment of thermal annealing.