Preparation And Application Of Multidimensional Biomimetic Nanomaterials Based On Chitosan

With the development of science and technology,there is a growing demand for high performance materials in various applications.The nanocomposites,which have many excellent properties in improving and even overcoming the defects of the individual nanomaterials,could make full use of the advantages of each building block and bring new properties.Although the nanocomposites are widely studied in various fields,there are still some limitations in nanocomposites,such as the poor mechanical property,inefficient functionality.It is known that nature have evolved a series of biomaterials with various unique hierarchical structures.These special structures gives biomaterials incomparable advantages in mechanical and self-healing performances.Therefore,the combination of nanocomposites with specific bio-mimic hierarchical structure has become be a hot topic in materials design.First of all,inspired by the nature,we successfully prepared a nacre-like GO-TCS-Fe₃O₄ ternary nanocomposites film with spraying method.By mimicking the layered structure of nacre and forming hydrogen bonds network and other chemical bonds,the composites film has exhibited excellent mechanical properties.The optimal tensile strength and toughness of the film are 308.4 MPa and 10.28 MJ/m³,respectively.At the same time,the ternary composites film has promising magnetic hyperthermia property.Under 30 KA/m,the temperature of the composites film could rise from 27? to 45 ? within 80 s and could maintain the temperature stably for a long time.This magnetic hyperthermia property could be used for antibacterial application.After treated by the composites film in the presence of an alternating magnetic field,the bacterial suspension were totally disinfected.Furthermore,we also prepared a GO-chitosan/ZnO double layer scaffold with honeycomb-like structure by using unidirectional freezing-drying method.The GO aerogel on the upper layer is designed for solar-thermal conversion and the unidirectional chitosan/ZnO aerogel at bottom serves as water transportation unite with anti-biofouling property.The double-layer scaffold can serve as a solar steam generation device with a high evaporation rate(?13.5 kg m^-2 h^-1)and efficiency??90.8%?under 10 sun.Especially,due to the anti-biofouling property,this GCZ scaffold remains an excellent evaporation rate(?13.3 kg m^-2 h^-1 and efficiency??89.4%? after cultivating in bacterial suspensions.In contrast,the evaporation performance of the ZnO-free scaffold was greatly suppressed due to the biofouling.These results demonstrate that the anti-biofouling design is important for increasing the devices lifetime in natural water and bacteria-contaminated water.