Dec 5, 2024
8:00pm - 10:00pm
Hynes, Level 1, Hall A
Miriam Rafailovich4,Radha Perumal Ramasamy1,Amirthapandian Sankarakumar2,Vinod Aswal3
Anna University1,Indira Gandhi Centre for Atomic Research2,Bhabha Atomic Research Centre3,Stony Brook University, The State University of New York4
Recently, magnetism has been observed in graphene and has been attributed to structural defects namely dislocations, vacancies, adatoms and impurity atoms [1-6]. In this work, polystyrene [PS] and graphene were mixed using plasti-corder (brabender) to have 88% PS and 12 % graphene. The samples were then hot pressed between brass electrodes. The samples were made in the shape of disc of 1 mm thickness and 2 cm diameter. The samples were irradiated with 100keV He
+ ions with the ion fluences 1×10
14 , 1×10
15 and 1×10
16 ions/cm
2 . The SEM analysis showed that (a) the surface has clear distinct light and dark regions in all the samples, (b) some fragments were observed to be present on the surface and (c) There are also more crater like structures in the ion irradiated samples. The ratio I
D /I
G where I
D and I
G are the Raman peak intensities of D band (1350 cm
-1 ) and G band (1582 cm
-1 ) is used to characterize the level of disorder in graphene. As disorder in graphene increases, I
D /I
G will increase. It was observed for un-irradiated samples that the G band was very prominent, when it is compared to the D band. For the ion fluences of 0, 1×10
14 , 1×10
15 and 1×10
16 ions/cm
2 , the ratio of I
D /I
G became ~ 0.07, 0.2, 0.5 and 0.9. This indicates that the disorder in graphene increases with increase in ion fluence. Small angle neutron scattering (SANS) is a useful technique to understand the microstructure of the nanocomposites. Using SANS it was observed that fractal structures were present in the ion irradiated and un-irradiated polystyrene graphene nanocomposites. The polymer dynamics and conductivity was studied using broadband dielectric relaxation spectroscopy (BDS). BDS analysis showed that the dielctric properties such as dielectric constant, dielectric loss, loss tangent, electric modulus were significantly affected by the presence of graphene in the nanocomposites. This research could benefit using graphene in batteries.
References:
1 Wang, Y.; Huang, Y.; Song, Y.; Zhang, X.; Ma, Y.; Liang, J.; Chen, Y. Nano letters. 2008, 9(1), 220-224.
2 Banhart, F.; Kotakoski, J.; Krasheninnikov, A.V. ACS nano. 2010 5(1), 26-41.
3. Singh R. Journal of Magnetism and MagneticMaterials. 2013, 346, 58-73.
4. Zhou, J.; Wang, Q.; Sun, Q.; Chen, X.S.; Kawazoe, Y.; Jena, P. Nano letters. 2009, 9(11), 3867-3870.
5. Wang, Y.; Huang, Y.; Song, Y.; Zhang, X.; Ma, Y.; Liang, J.; Chen, Y. Nano letters. 2008, 9(1), 220-224.
6. Ramasamy, R.P., Aswal, V.K., Rafailovich, M.H. and Halada, G. Journal of Materials Science: Materials in Electronics,2020, 31(21), pp.18344-18359.