Starch/Polyvinyl Alcohol/Eggsheell (Starch/PVA/EG) Blend Membranes with Turmeric Extract as a pH Responsive Sheets

Starch-based blend membranes is widely us in many application due to their biodegradability and low cost. Starch/Polyvinyl Alcohol/Eggsheell (Starch/PVA/EG) membranes were prepared with turmeric extract as a pH-responsive agent. Turmeric extract has good antioxidant activity and could act as a biosensor that changes color in different pH conditions. This research aims to study the effect of eggshells amount in the blend membranes on its thermal and pH-responsive properties. Starch/PVA/EG sheet was prepared by slip casting method. For pH responsiveness, the sheets were immersed into turmeric extract with 0,5 mg/mL in concentration for 24 hours and dried. Turmeric extract was analyzed using a spectrophotometer UV Visible to observe its response to pH and antioxidant activity. A pH-responsive sheet then analyzed the functional groups, thermal character, and the sheet's response in various pH conditions. A spectrophotometer UV Visible analysis shows that turmeric extract has shifted optimum peak in different pH conditions. An IC50 value of turmeric extract was 14.802 mg/L. Functional groups analysis showed that increasing eggshell addition had shifted peak of carbonyl groups at 1737 cm -1 to 1627 cm -1 . Presence of CO 3 2- in Starch/PVA/EG sheets were confirmed by peak at 889.18 cm -1 . A DSC analysis results the highest thermal stability was obtained by 50% EG. All the starch/PVA/EG sheets gave response to pH change.