Study On Controllable Preparation And Deformation Of Carbon Nanotube Aerogels

In nature,there are many materials that exhibit excellent performance based on neatly arranged structures,such as spider silk and shells.In addition,the excellent inherent properties of single carbon nanotubes have been widely used in many fields,but from a practical point of view,how to assemble single carbon nanotubes into a three-dimensional network that can be used macroscopically and maintain the original performance is a question worth thinking about.Based on the idea of bionics,combining the directional arrangement with the three-dimensional network structure to explore the influence of the microstructure construction method and the size of the pore size on the mechanical properties of the material has a very important application value.In this paper,carbon nanotube aerogels with directional structure were prepared,and their micro-morphology and mechanical properties were tested.According to the micro-morphology,different geometric and structural parameters were simulated in the finite element simulation software ABAQUS To explore the influence of different parameters on strength.First,the method of directional freezing was used to conduct practical research on the preparation method and process of carbon nanotube aerogel.Through the colloidal dispersion theory,a uniformly dispersed sodium carboxymethyl cellulosecarbon nanotube solution was prepared,combined with the methods of directional freeze-drying and high-temperature carbonization to obtain a carbon nanotube aerogel.In the preparation process,the parameters such as the concentration and amount of sodium carboxymethyl cellulose,ultrasonic time,high temperature carbonization at different temperatures,heating rate and other parameters were designed and improved.Scanning electron microscopy(SEM)was used to characterize the morphology of carbon nanotube aerogel.X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy were used to characterize the structure and bonding method of carbon nanotube aerogel.The universal testing machine tests the mechanical properties of carbon nanotube aerogels.Then based on the structural characteristics of the carbon nanotube aerogel micromorphology,in the finite element simulation software ABAQUS based on the thin shell theory,the simulation process of the static effect on the square structure composed of arched cells and hexagonal honeycomb cells was realized.For the arched element,the relationship between the three geometric parameters of the center angle ?,radius R,and sheet thickness ? on the structural strength is analyzed.The results of the orthogonal test design show that the wall thickness factor has the most significant influence on the strength,and the The main cause of hysteresis in the stress-strain curve is the friction between the sheets.The simulation results of the square structure composed of hexagonal honeycomb units show that the overall structure exhibits stronger bearing capacity when the pore size is smaller;the wall thickness of the repeating unit increases,the stronger the structure's resistance to deformation,the higher the strength,which is obtained from the arched unit The conclusions are consistent;Finally,comparing the two block structures of the equal hexagonal honeycomb structure and the long hexagonal honeycomb structure,the stress required by the former is obviously greater than that of the latter under the same strain,the former has more connection nodes and has a steric effect,When the same deformation is required,the load required is greater,the strength is higher,and the structure is more stable.The finite element simulation and experimental results are in good agreement.