Study On Structural Modulation And Compounding With Graphene Of Bacterial Cellulose For Adsorption Of Organics

Bacterial cellulose(BC) has been widely used in biomedical, photoelectronic, and environmental fields due to their unique architecture and properties and is considered to be one of the most potential nanomaterial. Structural controllability is necessary since the arrangement of the nanofibrils can greatly impact the performance.In this paper, the flowing fluid was created by using a homemade fermentor which forces the bacteria to move along the flowing direction to produce oriented BC nanofibers. The scanning electron microscope(SEM), atomic force microscopy(AFM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and universal material testing machine were utilized to analyze the microstructure, chemical structure, crystalline structure and mechanical properties. The results showed that, under the action of directional fluid, about 70% of the OBC nanofibers exhibit a declination angle of less than 20° and large-sized OBC scaffolds(280×60×3 mm3) could be produced. It was found that crystalline structure, surface chemistry and thermal stability of BC do not change although its crystallinity index is decreased to 77% from 91%. The tensile strength of OBC along the fiber direction was 1.2 MPa and the tensile strength perpendicular to fiber direction was 0.6 MPa.CSBC and CSBC/GE were prepared by dynamic culture and carbonization. SEM, TEM, XRD, FTIR, contact angle meter and universal material testing machine were utilized to analyze the microstructure and properties. The results indicated that CSBC and CSBC/GE showed ultra-low density(2.7 mg·cm-3 and 2.6 mg·cm-3), high porosity(96.5% and 98.4%), high specific surface(229.6 cm2/g and 340.2 cm2/g), hydrophobicity(CA=117.7° and 131.5°) and high flexibility. As a whole, CSBC and CSBC/GE can absorb the organic solvents up to 200~800 and 300~900 times their own weight respectively. No obvious change in absorption capacity was found after five absorption/distillation cycles. The excellent absorption capacity of CSBC and CSBC/GE was related to the division of large drops into small ones by the honeycomb-like surface, which promoted the penetration of small drops into the internal voids.In summary, we established a method to control the movement of Ax and realize structural control of the BC nonofibers. This work laid a solid foundation for the applications of BC.