Preparation and characterization of bacterial cellulose membranes with tailored surface and barrier properties

Modified bacterial cellulose membranes with tailored properties, regarding their surface and barrier properties were prepared by controlled heterogeneous esterification with hexanoyl chloride. The characterization of the esterified bacterial cellulose membranes was performed by FTIR spectroscopy, elemental analyses, X-ray diffraction, thermogravimetry and contact angle measurements. The esterified membranes showed an increased hydrophobic surface character, while preserving the bulk structure of the pristine material. The evaluation of the barrier properties was carried out through permeability measurements towards water vapor at different relative humidities and by the permeability towards humidified carbon dioxide, oxygen and nitrogen using the time-lag method. A decrease of roughly 50% in both water and gas permeation through bacterial cellulose membranes was observed after heterogeneous esterification. The bacterial cellulose membranes prepared are a good and interesting example of the development of bio-based materials with promising applications in the packaging industry.