1. Postgraduate School, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Medan 20155, Indonesia
2. Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Medan 20155, Indonesia
3. Cellulosic and Functional Materials Research Centre, Universitas Sumatera Utara, Medan 20155, Indonesia
4. Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Medan 20155, Indonesia
5. Department of Chemistry, Faculty of Science Technology and Information, Universitas Sari Mutiara Indonesia, Medan 20124, Indonesia
6. School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore