Bacterial NanoCellulose Characterization

This section summarizes analytical techniques that are used to characterize Bacterial NanoCellulose (BNC) and presents common physical, chemical methods enabling for detailed description of properties of the native and modified BNC.To characterize structure (determination of length and width of cellulose fibers and crosslinking of the fibers), most often used methods are electron microscopy (EM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), confocal laser scanning microscopy (CLSM), and CRM Confocal (RAMAN microscopy). Other important parameters that characterize BNC are crystallinity and degree of polymerization (DP). Techniques of cellulose crystallinity measurement involve XRD techniques, solid state ¹³C NMR, IR infrared spectroscopy, and Raman spectroscopy. Degree of polymerization can be determined by membrane osmometry, cryoscopy, size-exclusion chromatography, ebullioscopy, and determination of reducing-ends concentration. FTIR spectroscopy, GC/MS method, colorimetric analysis (e.g., the phenol-sulfuric method), SEC chromatography, or HPAEC (high performance anion exchange chromatography) can be used for the quantification of carbohydrate component of BNC. Mechanical properties of native and modified BNC usually involve measurement of Young's modulus, per cent elongation at break, and tensile strength.