1 Centre for Nanotechnology and Advanced Materials (CENTAM), Faculty of Science and Engineering, University of Nottingham Malaysia (UNM), 43500, Semenyih, Selangor, Malaysia. Kasturi.Muthoosamy@nottingham.edu.my.
2 Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan, BE1410, Brunei Darussalam. manickam.sivakumar@utb.edu.bn.