Stable microfluidized bacterial cellulose suspension

Abstract

In this work, nanofibrillated suspensions of bacterial cellulose (BC) were produced via microfluidization. The effects of the size of the openings of the microfluidizer chamber and ultrasonication on the nanofibril properties were evaluated. The results of the X-ray diffraction analysis indicated a considerable reduction in BC crystallinity (86–65%) and crystallite size (5.8–4.0 nm) after microfluidization and ultrasonication. Thermal analysis showed a remarkable reduction from 337 to 283 °C in the initial temperature of degradation along the several steps of BC deconstruction. Moreover, infrared analysis indicated that both processes led to an increase in the Iβ content (43–66%) of the fibers. Morphological analysis showed that the fibrillation process used exposed the internal faces of the ribbon-like nanofibrils, and thus, increased the surface area of the cellulose network, and produced fibers with a high aspect ratio (L/d). A thermally stable nanofibrillated suspension could be obtained by adding carboxymethyl cellulose as a simple and effective way to maintain cellulose fibers dispersed in the solution during sterilization by autoclaving.