TY  - JOUR
AU  - Aly, Emad Hassan 
PY  - 2011
TI  - Positron Annihilation Study on Nickel and Iron Nano-Particles in Natural Rubber Composites
JF  - American Journal of Applied Sciences
VL  - 8
IS  - 2
DO  - 10.3844/ajassp.2011.147.155
UR  - https://thescipub.com/abstract/ajassp.2011.147.155
AB  - Problem statement: The effect of Ni and Fe nano-particles as a filler on the free volume
properties Of Natural Rubber (NR) was studied using Positron Annihilation Lifetime Spectroscopy
(PALS). Approach: The PAL measurements revealed that the free volume properties are strongly
affected by the amount and type of filler. Results: Particularly speaking, the free volume fraction
dramatically decreased by increasing the filler content. Besides, the addition of nano-prticles created
new positron trapping sites at filler-rubber interfaces. Furthermore, correlations were made between
the free volume hole sizes (Vh) and each of the mechanical and electrical properties successively. A
negative correlation was observed between Vh and hardness in the Ni-rubber composites while a
positive counterpart was found in the case of Fe-rubber composites. Finally, the polarity of the fillers,
being higher than that of the rubber itself, leads to an increase in electrical parameters and an inhibition
of o-Ps formation. Conclusion: These results indicate that the investigated composites are considered
to be insulating materials as their conductivity values are in the order of an insulator range.