**5. Conclusion**

moduli plot. Nanocomposites were tough enough for the testing due to CNF support. The Young's moduli of these nanocomposites significantly increased and reached in the range 3.36 to 4.29 GPa. The tensile strengths also significantly increased in the range 31 to 59 MPa. It is important to notice that each Young's moduli and tensile strength of the chitin nanofiber composites were higher than that of CNF sheet or SSQ-UA copolymer. The higher Young's moduli and tensile strength of composite is due to SSQ-UA matrix embedded in every space of CNF sheet and strongly interacts with NF at the interface thus resulted in the increase of the reinforcement effect. The enhancements of mechanical properties of composite strongly support that a CNF sheet with a high Young's modulus (1.80 GPa) and a high tensile strength

**Figure 14.** Coefficient of thermal expansion (CTE) of SSQ-UA copolymer films and SSQ-UA-CNFs composites. Repro‐

**Figure 15.** Young's modulus and tensile strength of SSQ-UA copolymer and SSQ-UA-CNFs composites. Reproduced

with permission from ref. 6. Copyright 2012, Elsevier.

duced with permission from ref. 6. Copyright 2012, Elsevier.

98 Advances in Nanofibers

(30 MPa) worked effectively as a reinforcement filler for SSQ-UA copolymer.

Preparation of CNFs from crab, prawn shells, and a number of species of mushrooms have been discussed. Both chemical treatments and mechanical processing have been described in detail. CNFs prepared from crab shell, the presence of acidic medium was important to reduce the size of NFs. While in case of prawn shells the fibrillation was achieved in neutral conditions. Width of CNFs was 10-20 nm with high aspect ratio. After completion of fibrillation the CNFs were in physical state of wet gel of very high viscosity. Size of NFs was determined by recording FE-SEM of flakes or thin film of NFs. Apart from using grinder a newly developed high pressure jet atomization machine (Star Burst System; SBS) was also employed to fibrillate the NFs. Fibrillation was more effective when SBS was used that gave more thinner (19.0-16.5 nm) and homogeneous NFs compared to girder. NFs were characterized for chitin content by XRD and FT-IR measurements. CNFs were also prepared from five different species of edible mushrooms, NFs of width 20-28 nm were obtained. But the chitin yield in mushroom was lower (1.3-3.5 wt.%) compared to crab (12.2 wt.%) or prawn (16.7 wt.%). SSQ-UA copolymer-CNFs transparent composite sheets or thin film ware prepared and their optical, thermal, and mechanical properties were investigated. The properties improved on blending CNFs with copolymer to larger extent which has increased the scope of CNFs. CNFs were found effective to DSS-induced UC disease in mouse colon, the UC symptoms removed and lowered the MPOpositive cell count decreased significantly.

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