Preparation And Characterization Of Inorganic Nano Aerogels Composite Insulation Materials

With the development of society,China’s building scale is growing day by day,and the ecological and environmental problems caused by building energy consumption are becoming increasingly prominent.It is necessary to develop new high-performance thermal insulation materials.Silica aerogel is a high performance nanomaterial with very low thermal conductivity.It has excellent application prospects in the field of thermal insulation.However,the secondary particles between silica aerogels are mainly Fan Dehua force,and the bonding force is weak.This leads to poor mechanical strength of materials.Therefore,composite materials are often combined with other materials to develop their own heat insulation advantages and improve the overall performance of materials.This paper is devoted to the development of inorganic nano aerogels composite insulation materials with excellent performance.The main research work is as follows:First of all,glass fiber was used as toughening material,and silica aerogel particles and inorganic binder were combined to prepare glass fiber inorganic nano aerogel composite insulation material.The effect of aerogel 9wt%-19wt%on the structure and properties of the composites was investigated.The density distribution of the composite material was 0.851-0.924 g/cm~3,and formed a good silicon oxygen binding,and the pore size distribution was more uniform.Aerogels can increase the pore size of composites by virtue of their unique structure.At 900℃,the lowest mass loss is 5.22%;The minimum thermal conductivity of the composite at room temperature is 0.04 W/(m.K).Secondly,the combination of cement paste and glass bead is used as cementitious material.The cement based inorganic aerogel composite insulation material is developed by combining its adhesion with aerogel particles and inorganic binder.The effect of silica aerogel 0wt%-15wt%on the structure and properties of the composites is investigated.The dense silica network exists in the composites,and the average pore size and BET specific surface area increase with the increase of aerogel content.The amount of aerogel and the density of composites meet y=-0.0174X+0.6701.The thermal conductivity and aerogel content of the composites basically conform to y=-0.00505X+0.15264,and the lowest thermal conductivity is 0.082 W/(m.K).The hydrophobicity of the composites increases with the addition of aerogels,the maximum contact angle is 117.57 degrees,and has excellent hydrophobic properties.Finally,carbon fiber reinforced phase,cement paste and glass bead were used as cementitious materials,and silica aerogels and inorganic binder were combined to prepare carbon fiber cement based nano aerogels composite insulation materials.The effect of carbon fiber 0wt%-5wt%on the structure and properties of composites was studied.The density of composites was 0.43-0.48kg/m~3.There is Si-O covalent bond vibration in the material,forming a good interface bonding;With the increase of carbon fiber content,the specific surface area decreases,and the average pore size first increases and then decreases;When the content of carbon fiber is 1wt%,the thermal conductivity of the composite is 18.27%lower than that of the composite without carbon fiber,as low as 0.08 W/(m.K),indicating that a good micro thermal conductivity network is formed in the composite.