Spectroscopic Optical Band Gap Properties and Morphological Study of Ultra-High Molecular Weight Polyethylene Nano Composites with Mg0.15Ni0.15Zn0.70Fe2O3

• Main Author: Azam, Asad Muhammad
• Format: Others
• Language: English
• Published: Umeå universitet, Institutionen för fysik 2016
• Subjects: Physics(optical properties
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-115809

Ultra high molecular weight polyethylene has been commonly used as a biomaterial for hip and knee implants. This thesis concerns optical and three phase morphology of nano composites of ultra high molecular weight polyethylene (UHMWPE) with Mg0.15Ni0.15Zn0.70Fe2O3 using analytical techniques such as UV-visible spectroscopy and Raman spectroscopy. Muller matrix spectro-polarimeter has been used to study the absorption behavior over the visible spectral range i.e. 400-800 nm. The results show significant changes in the absorption behavior of UHMWPE/Zn nano ferrite samples. To analyze these changes in pure and UHMWPE/Zn-nano ferrite composites, the Urbach edge method was used for the calculation of optical activation energy. Moreover, direct and indirect energy band gaps, and the number of carbon atoms in C=C unsaturation have been evaluated by using the modified Urbach formula and Tauc’s equation, respectively. The results show that the optical activation energy decreases more with the addition of 2wt% Mg0.15Ni0.15Zn0.70Fe2O3 than 1wt% of Mg0.15Ni0.15Zn0.70Fe2O3. The values of direct and indirect energy band gaps are also found to decrease more with 2wt% of Mg0.15Ni0.15Zn0.70Fe2O3. Furthermore, indirect energy gaps are found to have lower values as compared to direct energy gaps. The numbers of carbon atoms in clusters determined from modified Tauc’s equation were approximately the same for 1wt% and 2 wt% of Mg0.15Ni0.15Zn0.70Fe2O3 but differ for pure UHMWPE. The degree of crystallinity obtained from Raman spectroscopy was 42%, 43%, and 42% for UHMWPE, UHMWPE+1% of Mg0.15Ni0.15Zn0.70Fe2O3, and UHMWPE+2% of Mg0.15Ni0.15Zn0.70Fe2O3, respectively, i.e. about the same, but the relative amount of interphase and amorphous regions varied. Optical activation and sub band gap energies can be estimated for utilization of this composite in applications such as optical sensors, solar cells etc.