Assembly And Mechanical Properties Of Calcium Carbonate/Hydroxy Apatite Nanowires

Nature has generated a large number of fascinating biomaterials over billions of years of evolution.Due to their reasonable interface design and layered structure,biomaterials typically exhibit excellent mechanical properties.As a result,researchers have devoted themselves to study their mechanical enhancement mechanisms,with the aim of developing artificial biomimetic materials that can advance the modern materials industry.One-dimensional(1D)nanomaterials,which resemble wire-like structures with high aspect ratios,possess excellent properties,but their their large-scale controlled assembly remains limited.Based on this research backdrop,this thesis develops efficient assembly methods and investigates their enhancement mechanism of the mechanical property.On this basis,we prepare nanowire thin films that mimic the structure of shells,beetle exoskeleton and tooth enamel.The primary research focus is outlined below:1.we propose a method for the preparation of nanowire films that imitate the structures of shells and beetle exoskeletons.And the mechanical properties are regulated by modulating the microstructure of the films.In this work,we propose an assembly strategy with an ordered structure close to that of biological materials,inspired by the "brick-mortar" structure of mother-of-pearl and the Bouligand structure of beetle exoskeleton.We use inorganic calcium carbonate nanowires(CC NWs)and organic binder polyacrylamide(PAM)as raw materials.A composite film is then prepared by the modified Langmuir-Blodgett(LB)interface assembly method.By varying the ordering degree of the films,the alignment angle between CC NWs,the type and concentration of the organic binder,we obtain composite films with varying mechanical properties.We investigate the underlying mechanical enhancement mechanisms using COMSOL simulation software,providing a novel research approach for developing biomimetic materials.2.A biomimetic assembly method is developed to prepare nanowire films composed of hydroxyapatite nanowires(HAP NWs)with sodium alginate(SA)to mimetic the microstructure and mechanical properties of natural tooth enamel.The results indicate that this multi-scale design is suitable for the large-scale production of high-performance biomimetic mechanically reinforced materials.