Fabrication of bacterial cellulose thin films self-assembled from sonochemically prepared nanofibrils and its characterization

•Development of bacterial cellulose colloid dispersions using ultrasound irradiation.•Self-assembled film formation of the supernatant phase via solvent evaporation.•Purification treatment had a critical effect on the removal of bacteria impurities.•Ultrasound and drying processes had an important effect on the morphology and properties of bacterial cellulose films. Bacterial cellulose (BC) film formation could be a critical issue in nanotechnology applications such as biomedical or smart materials products. In this research, purified pretreated BC was subjected to high intensity ultrasound (HIUS) and was investigated for the development of BC films. The morphological, structural and thermal properties of the obtained films were studied by using FE-SEM, AFM, FT-IR, XRD, TGA and DSC characterizations. Results showed that the most favorable purification treatment was the 0.01M NaOH at 70°C for 2h under continuous stirring. The most suitable ultrasound operating conditions were found to be, 1cm distance of ultrasonic probe from the bottom of the beaker, submerged in cold water bath cooling around 12±2°C. The power (25W/cm2), time (30min), BC concentration (0.1%w/w), amplitude (20μm) and frequency (20kHz) were maintained constant.