Development of a gel permeation chromatography method for the determination of molecular weight of bacterial cellulose and cellulose nanocrystals

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Cellulose derived from plant sources is one of the most abundant natural biopolymer and finds applications in many products in our daily life. As a polymer, application is strongly dependent on its molecular weight. Gel permeation chromatography is one of the standard methods for molecular weight determination which requires the dissolution of the polymer to form a solution. However strong hydrogen bonding which hinders cellulose solubility in most solvent systems makes its molecular weight determination difficult. There a few solventsystems that are found to be suitable. Bacterial cellulose, produced by bacteria, is in the form of nanofiber that is substantially pure. Due to its high degree of crystallinity, it is especially challenging to find a suitable solvent system. Similar problem exists for cellulose nanocrystals which are also highly crystalline and difficult to dissolve. As a result, no definitive molecular weight has been determined for bacterial cellulose even though medical devices including replacement dura mater and occlusive wound dressing are already commercialized and many potential biomedical and medical device applications are being pursued. This project will investigate solvent systems for effective bacterial cellulose dissolution and develop a new procedure for molecular weight determination of bacterial cellulose. A range of solvent systems in combination with GPC columns and GPC operating conditions will be investigated. Upon completion of the project, a standard operating procedure using GPC for molecular weight determination of bacterial cellulose and cellulose nanocyrstals will be developed. This procedure can also be applied to conventionally derived plant cellulose.