CAJ | 학술논문

研究了纳米铁填充的碳纳米管基复合纤维在空气中的热氧化性能.结果表明:一般在室温即被氧化的铁(Fe)纳米粒子在170℃仍然具有良好的稳定性.这一方面是由于碳纳米管的保护作用所致.另一方面碳纳米管末端的Fe纳米粒子在室温下即迅速被氧化成反尖晶石型Fe3O4/γ-Fe2O3,170℃以下能有效阻止氧分子向碳纳米管内扩散.因此.170℃可以被看作氧分子扩散进人碳纳米管腔的极限温度.在170℃以下时,氧分子无法渗透Fe3O4/γ-Fe2O3晶格在管腔中形成氧分子.当温度高于170℃时,氧分子渗透发生,管腔内的Fe纳米粒子由靠近管末端位置到内部逐渐被氧化.由于相对良好的热氧化稳定性.Fe填充碳纳米管基复合纤维的铁磁性将可以在更高温度范围内得以保持.
연구료납미철전충적탄납미관기복합섬유재공기중적열양화성능.결과표명:일반재실온즉피양화적철(Fe)납미입자재170℃잉연구유량호적은정성.저일방면시유우탄납미관적보호작용소치.령일방면탄납미관말단적Fe납미입자재실온하즉신속피양화성반첨정석형Fe3O4/γ-Fe2O3,170℃이하능유효조지양분자향탄납미관내확산.인차.170℃가이피간작양분자확산진인탄납미관강적겁한온도.재170℃이하시,양분자무법삼투Fe3O4/γ-Fe2O3정격재관강중형성양분자.당온도고우170℃시,양분자삼투발생,관강내적Fe납미입자유고근관말단위치도내부축점피양화.유우상대량호적열양화은정성.Fe전충탄납미관기복합섬유적철자성장가이재경고온도범위내득이보지.
Thermal oxidation of Fe nano-particles in nanoscopic reactors of carbon nanotubes (CNTs) was investigated by treatment in air from room temperature to 800℃. It is found that encapsulated Fe nano-particles are thermally stable up to a relatively high temperature of 170℃ comparing to oxidization at room temperature of bare ones. Fe nano-particles in the tube end of CNTs is easily oxidized to form inverse spinel structure Fe3O4/γ-Fe2O3 nano-particles, serving as barriers to prevent oxygen from diffusion into the inner hollow cavity of CNTs. It is suggested that 170℃ is the critical temperature (Tc) of oxygen diffusion through the barriers. At temperatures lower than 170℃, oxygen molecules can not diffuse through the lattice of Fe3O4/γ-Fe2O3 nano-particles to form oxygen molecules in the cavity of CNTs, while at higher temperatures the penetration of oxygen occurs and Fe nano-particles from the tip to inner most in CNTs are gradually oxidized. The mechanism is different from the oxidation behavior and thermal stability of a CNT-encapsulated Fe nanowire, which is oxidized continuously once the oxidation occured by oxygen ions migrating through the lattice of iron oxides and combines with Fe atoms to complete the oxidation process.