Preparation Of Sodium Titanate Aerogel And Simulation Of Its Thermal And Mechanical Properties

Nanomaterials and nanostructures exhibit outstanding optical,electrical,magnetic,mechanical,and thermal properties,which make them have potential application in many fields.Aerogel is a representative nanostructure,which is composed of nanomaterials through the macroscopic assembly.Aerogels are one of the least dense solids in the world and can be generally classified into inorganic aerogels,organic aerogels,and organic-inorganic hybrid aerogels according to their composition.Aerogels are excellent thermal insulators,which can block the heat conduction and convection.The composition,structure,thermal and mechanical properties of aerogels are the key factors affecting their applications.At present,the application of various types of aerogels in the field of thermal insulation is limited by the following factors:（1）Although carbonaceous organic aerogels are light and soft,they are easy to react with O₂under high temperature and oxygen-containing conditions;（2）Inorganic ceramic aerogel is light in weight and resistant to high temperature,but is brittle and fragile.Nowadays,industries such as aerospace,building materials,energy,chemicals,and even clothing fabrics have very urgent demands for refractory insulation materials,especially aerogel materials with good thermal stability,excellent mechanical properties,and insulation.Therefore,the development of aerogel materials with excellent mechanical properties,high-temperature stability,and thermal insulation has become a hotspot in the field of materials research.As a new type of inorganic ceramic material,sodium titanate has been gradually explored and applied in catalysis,battery materials,and sensors.However,its potential in thermal insulation remains to be developed.As a new type of ceramic material,sodium titanate has the advantages of low density,high-temperature resistance,corrosion resistance,etc.,but at the same time,there are disadvantages such as the inherent brittleness of ceramic materials.Structural optimization of nanomaterials has become a feasible solution to improve their properties.Affected by small-scale effects,as the material’sgeometries are reduced to the nanoscale,materials may exhibit good toughness and elasticity.Therefore,in this paper,sodium titanate nanofibers were prepared by a hydrothermal method,and then macro-sized sodium titanate aerogels were assembled by a simple method.The thermal conductivity of the prepared Na₂Ti₃O₇ material was about 0.052 W·m^-1·K^-1at 25℃.The thickness of Na₂Ti₃O₇-based insulating material can be adjusted.And its thermal and mechanical properties have been studied.The material shows great potential for fireproof fabrics,high temperature gas filtration and thermal insulation interlayers.The high thermal stability and mechanical properties of Na₂Ti₃O₇ nanobelts endow the thermal insulation material with excellent structural stability,flexibility and good compression flexibility.The main contents include:（1）Using titanium dioxide as the precursor,the sodium titanate aerogel was prepared by a hydrothermal method in an alkaline environment.And then the inorganic aerogelwas prepared by a vacuum filtration method.Its structure and microstructure were characterized by scanning electron microscopy and X-ray diffraction.（2）Based on the real structure of sodium titanate aerogel,an aerogel skeleton model was established.Based on heat conduction theory and mechanical analysis,the thermal insulation performance and compressive performance of the model were analyzed by Digimat software.（3）The heat transfer properties and compressive mechanical properties of sodium titanate aerogel are systematically characterized by infrared thermal imaging camera,universal testing machine and other detection and analysis technologies.The thermal conductivity,mechanical stability and fatigue properties of aerogel are obtained,and the software simulation results are compared.