Improved Permeability Properties for Bacterial Cellulose/Montmorillonite Hybrid Bionanocomposite Membranes by In-Situ Assembling

Bacterial cellulose/montmorillonite (BCMMT) hybrid bionanocomposite membranes were prepared by in-situ assembling or one-step biosynthesis process. The presence of MMT in BC membranes was confirmed by thermogravimetric analysis and quantified by mass spectrometry, resulting in bionanocomposites with MMT contents between 7-13 wt%. The incorporation of MMT during BC biosynthesis modified BC morphology and led to lower porosity, even though higher water holding capacity was achieved. Bionanocomposites showed improved thermal stability and water vapor and oxygen gas barrier properties up to 70 and 80% with respect to neat BC membranes. This improvement was related to the tortuous path of gas diffusion created by MMT nanoplatelets due to the high extent of dispersion achieved, as observed by XRD. SEM micrographs confirmed MMT was finely dispersed between BC nanofibrils and a more compact structure was observed as MMT content increased. Thus, the in-situ process can be used as an alternative method to obtain cellulose/MMT hybrid bionanocomposite that would have potential applications as reinforcing element.