Cellulosic fibrils hierarchical structure

Nanofibrils can be extracted from natural resources, since many cellulosic fibres (such as cotton, hemp, flax) or protein fibres (such as wool, silk from silkworm or spider) have hierarchical structures composed of fibrils in nanoscale sizes. 

Natural fibers consist of aggregated cellulose chains arranged in a hierarchical structure. These elementary fibrils are composed of cellulose chains called cellulose macro fibrils [16]. Figure 6.3 shows a fransmission elecfron microscopy (TEM) image of cellulose microfibrils, or MFC [17],... 

Cellulose, the most abundant renewable organic material produced in the biosphere, is extracted from plants, bacteria, algae, fungi, and tunicates [28]. The structure of nature-derived cellulosic materials is hierarchical. The primary building unit of cellulose is p-l,4,-linked-anhydro-D-glucose. A discrete number of cellulose molecules pack in a parallel fashion to form elementary fibrils, also known as... 

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