SiO_(2)纳米管气凝胶的制备工艺及性能  

Preparation and Properties of Silica Nanotube Aerogels

作　　者：李宁[1] 牛瑞文 何智兵[1] 易泰民[1] 李婧[1] 张帅[1] 杨蒙生[1] 陈云建 柯博[1] LI Ning;NIU Ruiwen;HE Zhibing;YI Taimin;LI Jing;ZHANG Shuai;YANG Mengsheng;CHEN Yunjian;KE Bo(Research Center of Laser Fusion,China Academy of Engineering Physics,Mianyang 621900,Sichuan,China)

机构地区：[1]中国工程物理研究院,激光聚变研究中心,四川绵阳621900

出　　处：《硅酸盐学报》2024年第12期3695-3702,共8页Journal of The Chinese Ceramic Society

基　　金：中国工程物理研究院院长基金(YZJJLX2020008)。

摘　　要：SiO_(2)气凝胶在隔热、吸附、催化等领域有着广泛应用,为进一步改善其力学性能、加工性能,本工作以碳气凝胶为模板,正硅酸乙酯为硅源、氨水为氧源,通过化学气相沉积方法制备得到具有三维纳米管多孔结构的SiO_(2)纳米管气凝胶。研究反应温度、压力对材料微结构、密度的影响,制备获得组织均匀的SiO_(2)纳米管气凝胶,需匹配反应物的传质速率和反应速率。制备的SiO_(2)纳米管气凝胶具有优异的力学性能及突出的结构可靠性,材料弹性模量为0.70 MPa,60%应变时对应的材料应力为0.83 MPa,在压缩应变很大时没有发生脆性断裂。此外SiO_(2)纳米管气凝胶可采用车削、铣削、激光加工等多种手段加工成型,表现出了优异的加工性能。Introduction Silica aerogels are highly porous materials with interconnected three-dimensional networks of silica particles,which are typically obtained via removing the liquid in gels under supercritical conditions.Silica aerogels are widely applied in the fields of thermal insulation,adsorption,catalysis,and energy storage due to their ultralow density,large surface area,and unique nanoporous structure.However,silica aerogels are fragile at relatively low stresses due to the existence of rigid skeleton consisting of weak linking of silica particles.The inherent brittleness and poor reliability restrict the application of aerogel materials to a certain extent.In this paper,the preparation and properties of SiO_(2)nanotube aerogels(SiO_(2)–NTA)with a three-dimensional nanotubular network structure were investigated.Methods For the prepatation of carbon aerogels(CA)as sacrificial templates,3.24 g of resorcinol and 4.4 m L of formaldehyde solution were dissolved in 95.5 mL of deionized water.The solution was stirred for 1 h,and 3.9 mg of sodium carbonate was added.After further stirring for 30 min,the precursor solution was poured into a container,sealed and cured in an oven at 85℃for 72 h to obtain a resorcinol-formaldehyde wet gel.The gel was washed with ethanol for several times to completely remove the residual solvents.The wet gel was dried using supercritical carbon dioxide to obtain the resorcinol-formaldehyde aerogel,which was subsequently placed in a tubular furnace and carbonized in a nitrogen atmosphere to obtain the CA templates.SiO_(2)–NTA were prepared via chemical vapor deposition(CVD)with argon as carrier gas,tetraethoxysilane and aqueous ammonia solution as silicon and oxygen sources,respectively.Firstly,tetraethoxysilane source tank was heated to 60℃.Then,CA templates were placed in CVD chamber,and was heated to different deposition temperatures(i.e.,100,150,200,250℃ and 300℃),respectively.C/SiO_(2)composite aerogels(CA@SiO_(2))were prepared via introducing tetraethoxysilane(5 mL/min)a

关 键 词：二氧化硅 纳米管气凝胶 力学性能 加工性能 

分 类 号：TB332[一般工业技术—材料科学与工程]