VNU Journal of Science Mathematics – Physics, Vol 37, No 2 (2021) 77 83 77 Original Article Synthesis and Characterization of Silver Nanoparticles for Antibacterial Application against Bacillus Subtilis and Pseudomonas Aeruginosa Pham Thi Thu Ha1, Vu Xuan Hoa1,, Trinh Dinh Kha1,2, Nguyen Dac Dien3, Luong Duy Thanh2, Nguyen Quang Hung4, 5, Luong Van Luyen6 1TNU University of Sciences, Tan Thinh, Thai Nguyen, Vietnam 2Thuyloi University, 175 Tay Son, Dong Da, Hanoi, Vietnam 3Vietnam Trade Union U[.]