Tran Trong Hieu Dinh, Hoang Hao Lam, Thanh Danh Tran, Quang Luan Le, Van Man Tran, Truc Phuong Huynh, Van Phuc Dinh, Anh Tuyen Luu, Kim Ngoc Pham and Duy Tap Tran 2022. Investigation of the water states of poly(styrene sulfonic acid) grafted poly(ethylene-co-tetrafluoroethylene) copolymer using FT-IR analysis. Vietnam Journal of Science, Technology and Engineering. 64, 2 (Jun. 2022), 3-9. DOI:https://doi.org/10.31276/VJSTE.64(2).03-09.