Tur-Ridha Noer Khalifah, - and Hasnah Natsir, - and Siti Fauziah, - and Indah Raya, - Synthesis and Characterization of Hydrogels Derived from Cellulose of Water Hyacinth (Eichornia crassipes) and Chitosan Using the Freeze Thaw Method. © 2022 Trans Tech Publications Ltd, Switzerland.