Acetylation of Nata de coco (bacterial cellulose) and membrane formation

• Published in: MATEC Web of Conferences 2019, Vol.268, p.4003
• Main Authors: Alberto, Erika Louise, de Ocampo, Ailey Nicole, Depasupil, Christopere Ghil, Ligaray, Mayzonee, Eusebio, Ramon Christian, Orbecido, Aileen, Beltran, Arnel, Patacsil, Liza
• Format: Article
• Language: English
• Subjects: Acetylation; Anhydrides; Cellulose; Deionization; Dissolution; Evaporation; Lithium chloride; Solvents; Submerging; Titration
• ISSN: 2261-236X; 2274-7214; 2261-236X
• DOI: 10.1051/matecconf/201926804003

Nata de coco (NDC), a bacterial cellulose formed by Acetobacter xylinum , was utilized to fabricate a membrane via acetylation and phase inversion methods. The NDC was activated and dissolved in N,N-Dimethylacetamide (DMAc) with lithium chloride (LiCl) at varying amounts of NDC, LiCl/DMAc ratio, activation temperature, and dissolution temperature. Acetylation was done by adding acetic anhydride (in a mass ratio of 1:12 NDC-anhydride) to NDC-DMAc/LiCl solution at a dissolution temperature of 110 °C for 3 hours. The modified-NDC was recovered via precipitation in methanol. The modified-NDC was washed with deionized water then freeze-dried. Modification was verified by determining the degree of substitution (DS) using titration and FTIR analysis. It was observed that the modification could be carried out at an NDC/DMAc (w/v) ratio of 1:75 at 120 °C for 1 hour, and addition of 8% (w/v) LiCl catalyst at 110 °C for 20 minutes. The DS of the modified-NDC was observed in the range of 2.84 – 3.69, which indicates a successful modification. This was further verified by the FTIR results. Membrane fabrication was carried out using the modified-NDC via immersion-precipitation and solvent evaporation methods. A successful membrane formation was observed using solvent evaporation.