Bacterial cellulose processing techniques

Native cellulose are commonly modified by physical, chemical, enzymic, or genetic means in order to obtain specific functional properties, and to improve some of the inherent properties that limit their utility in certain application. Physical/surface modification of cellulose are performed in order to clean the fiber surface, chemically modify the surface, stop the moisture absorption process, and increase the surface roughness. " Among the various pretreatment techniques, silylation, mercerization, peroxide, benzoylation, graft copolymerization, and bacterial cellulose treatment are the best methods for surface modification of natural fibers. 

Extrusion and impregnation, electrospinning, and multilayer films are other processes applicable for reinforced nanocomposites. Thus, preparation of cellulose whiskers reinforced with polylactic acid nanocomposites (by melt extrusion carried out by pumping the suspension of nanocrystals into the polymer melt during the extrusion process), using polyvinyl alcohol as a compatibilizer for the dispersion of cellulose whiskers within the polylactic acid matrix, was reported (de Menezes et al. 2009) bacterial cellulose whiskers incorporated into poly(oxyethylene) nanofibers by electrospinn to enhance the mechanical properties of electrospun fibers (Peresin et al. 2010) or the use of the layer-by-layer assembly technique, which maximizes the interaction between cellulose whiskers and a polar polymeric matrix (Bruno et al. 2009 Aulin et al. 2010), are some examples of nanocomposites reinforced by the last three methods. 

There are a number of common techniques that researchers use to characterize bacterial cellulose. Whilst this is by no means a comprehensive list, these techniques do provide a good indication of alterations that may have occurred during the cultivation of the bacteria, as cellulose polymerization and crystallization are closely coupled processes, and changes to the cultivation conditions can change the structure and morphology of the resulting cellulose [35]. 

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