Hydrophilic nanofiber of bacterial cellulose guided the changes in the micro-structure and mechanical properties of nf-BC/PVA composites hydrogels

Hydrophilic nanofibers derivate from bacterial cellulose (nf-BC) were compounded with PVA colloidal sol to form physical crosslinking hybrid hydrogels. With the hydrophilic and hydrogen bonding interaction between the groups of PVA and nf-BC during the composite gel phase transformation process, a regular and uniform distributed porous structure was formed which interconnected through fibrous funicular cords composed of PVA gel along nf-BC orientation by controlling the content of nf-BC and gel transition condition. The micro-morphology, chemical structure, crystallinity and mechanical properties of the nf-BC/PVA hydrogels changed with the different proportion and distribution of nf-BC. It has been verified that hydrophilic nf-BC acts as “crosslinking agent” and reinforced phase which can guide the composite hydrogels to form more ordered and compact porous structure, via enhancing the interaction of hydrogen bonds and physical crosslinking points between nf-BC and PVA macromolecule, finally resulted in the enhancement of their mechanical performances. The composite hydrogels have broad application prospects in the field of medicine, such as artificial cartilage, blood vessel, wound dressing and so on.