【摘要】 采用NaOH/十二烷基苯磺酸钠（DBS）/甲苯/水和NaOH/十六烷基三甲基溴化铵（CTAB）/三氯甲烷/正丙醇/水2种微乳液体系制备了γ-Fe₂O₃纳米粉体,并对其气敏性能进行了研究和讨论。用FT-IR、XRD和TEM测试技术对纳米粉体进行了结构表征。结果表明,选用DBS和CTAB作为表面活性剂,在W/O分别为10．77和10．56的条件下均可获得粒径为4～5 nm的球形γ-Fe₂O₃纳米颗粒。由于获得的γ-Fe₂O₃纳米颗粒表面均有残余的表面活性剂存在,导致产物颗粒之间不易团聚,粒径较小。由2种微乳液体系制备的γ-Fe₂O₃纳米粉体制作的气敏元件,对体积分数为0．1％的乙醇的灵敏度分别为12．5和23．8,并测得元件DBS的响应-恢复时间分别为20和30s;元件CTAB的响应．恢复时间分别为15和47 s。元件的灵敏度与所测气体的浓度呈线性关系。更多还原

【Abstract】 γ-Fe₂O₃ nanopowders were synthesized from the two microemulsion solutions,such as NaOH/ DBS/C₆H₅CH₃/H₂O and NaOH/CTAB/CHCl₃/CH₃CH₂CH₂OH/H₂O,and their gas sensing properties were studied.The products were characterized by means of FT-IR,XRD and TEM.The results indicate that spheri- calγ-Fe₂O₃ nanoparticles with a particle size of about 4～5 nm can be obtained from the two microemulsion solutions,when DBS and CTAB were used as surfactant and the ratios of W/O were 10.77 and 10.56, respectively.The small particle size can be attributed to the remanant surfactants adsorbed onγ-Fe₂O₃ nano- particles which prevent the aggregation ofγ-Fe₂O₃ nanoparticles.The sensors,made fromγ-Fe₂O₃ nanopow- ders obtained from the two microemulsion solutions,have high sensitivities of 12.5 for DBS and 23.8 for CTAB to 0.1% ethanol,as well as show short response-recovery time to 0.1% ethanol,that is,20 and 30 s for DBS and 15 and 47 s for CTAB,respectively.Both of them can meet the requirements of practical applications and are promising ethanol sensors due to their sensitivities and good linear relations to the concentration.更多还原