Cellulose Nanocrystals and Nanofiber from Sub-Wear out Brazilian Semiarid Source for Biological Applications

Nowadays, the development of sustainable materials using chemical routes that are less harmful to the environment, adding social and economic viability to developed countries is a significant challenge. In this context, the present study extracted cellulose nanocrystals (CNC) based on two different chemical routes (H₂SO₄ and H₂SO₄/HCl) using a sub-wear out fiber from a natural resource in the semiarid Brazilian region with proposal of social and economically promoting this area and produce low-cost CNC. The two CNC (CNC H₂SO₄ and CNC H₂SO₄/HCl) were extensively characterized by spectroscopic analysis (FTIR, XPS, UV-Vis), X-ray diffraction, and morphological analysis (SEM, TEM). In addition, morphological analysis was performed after heat treatment to analyze the dependence on the thermodynamic kinetic in nucleation and growth of nanocrystals. The CNC biocompatibility was tested using a Resazurin assay. The results showed differences in morphologies, crystalline structures and chemical groups in the CNC depending on the chemical route. The sizes of CNC H₂SO₄ and H₂SO₄/HCl were 30 and 50 nm, respectively. The cytotoxicity studies were statistically similar showing biocompatibility (approximately 90%). Thus, these results indicated the potential to the possibility to improve social and economic conditions in the semiarid Brazilian region using a sub-wear-out waste as source producing a final product with aggregate value to the market.