Nguyen Thi, Ngoc Tram, 1 Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam 2 Institute of Applied Materials Science, Vietnam Academy of Science and Technology, 01 TL29, District 12, Ho Chi Minh City 700000, Vietnam 3 Tra Vinh University, No. 126, Nguyen Thien Thanh, Ward 5, Tra Vinh city, Tra Vinh Province 940000, Vietnam