Endang W. Laksono, Puspitaningsih, Das Salirawati, Heru Pratomo
This study aims to synthesize and characterize cellulose films from tofu wastewater with the addition of sorbitol plasticizers and lemongrass oil. The making of sorbitol cellulose films used the fermentation method by varying the concentrations of sorbitol (0,3,6, and 9% v/v) which were added during the fermentation of nata de soya. The sorbitol cellulose film with the best mechanical properties was immersed in lemongrass oil with time variations (3,5, and 9 days). Characterization includes determination of functional groups using FTIR-ATR, mechanical properties, water resistance, moisture absorption, hydrophobicity, and antibacterial activities. The results showed that sorbitol concentration affected the mechanical properties of the film. Tensile strength values 4,5028-7,4582 MPa, percent elongation 10,2719-25,6799%, and modulus young 17,53-39,38 MPa. The higher sorbitol plasticizer concentration increased the percent elongation, lowering the tensile strength, resistance to water and water vapor. The addition of lemongrass oil reduces the percentage of lengthening. The contact angle value of the sorbitol cellulose film with lemongrass oil more than 30o means that it is weak to hydrophobic properties. The longer of soaking with lemongrass oil, the wider zone of bacteria inhibition against E. coli and S. aureus. The best antibacterial activity occurs at 9 hours by One Way ANOVA analysis showed significant results with a significance value of 0.00<0.05. Immersion for 9 days resulted the largest inhibition zone diameter based on Duncan's analysis. © 2025 Author(s).
Chemistry Education Department, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia
