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

Abstract

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.

Nanocellulose in Thin Films, Coatings, and Plies for Packaging Applications: A Review

“…Chemical modification of the cellulose (Tome et al 2010) Use of additives to the film (Pereda et al 2014) Waxes and other coatings on the film (Kisonen et al 2015) Curable cross-linking treatments (Aulin and Ström 2013) Allow residual lignin in the composition (Rojo et al 2015) Films break due to stress above their strength at the weakest point.…”

“…Tchang Cervin et al (2014) used a similar approach to achieve a hydrophobic solid foam of NFC; the hydrophobic treatment of the cellulose rendered the product hydrophobic. Tome et al (2010) derivatized bacterial cellulose membranes by esterification with hexanoyl chloride. The water contact angle was increased, along with resistance to water and gas diffusion.…”

10 Swelling and barrier properties

“…When increasing the acetylation reaction time and then the degree of substitution (DS), an initial reduction of WVTR was observed. WVP of BC membranes was decreased by conducting controlled heterogeneous chemical modification with hexanoyl chloride as shown in Figure 10.3 (Tomé et al, 2010). This decrease was explained by the increasing fraction of acetylated hydroxyl groups which gradually decreased the solubility of water in the amorphous zones of the MFC structure.…”

“…Gas permeation of carbon dioxide, oxygen and nitrogen in unmodified and esterified BC membranes were also evaluated at 25°C and 100% RH (Tomé et al, 2010). The esterification of BC membranes with hexanoyl chloride caused a significant decrease in the permeability towards CO 2 , O 2 and N 2 because of the insertion of fatty aliphatic chains on the membrane surface and ensuing increase of its hydrophobic character.…”

“…Permeability towards water vapor (WVP) in bacterial cellulose membranes before (CB) and after esterification with hexanoyl chloride (BCC6) at different relative humidities (RH)(Tomé et al, 2010).…”