摘要
VO_(2)的相变温度68℃限制了其在室温环境中的应用和安全性,采用W^(6+)离子掺杂的方法可有效降低VO_(2)相变温度。利用涂有真空硅脂的聚苯乙烯模具和添加表面活性剂的W_(x)V_(1-x)O_(2)纳米溶液,在玻璃基底上通过双相界面自组装方法将水热法合成的W_(x)V_(1-x)O_(2)纳米粉末制备成薄膜,在此基础上加装直径1μm的聚乙烯线制备W_(x)V_(1-x)O_(2)/glass微结构。直接观察到液/固双相界面上毛细管流的运动过程,以及微结构两侧对称出现半月形的现象。液-固-气系统复杂的动态变化的过程,遵循流体动力学和热力学的规律。X射线衍射表征结果表明,自组装W_(x)V_(1-x)O_(2)薄膜为多晶结构,主要成分为M相VO_(2)和少量钒的其他价态氧化物及少量钨钒的氧化物(WVO_4);近红外透过率测试显示W_(x)V_(1-x)O_(2)/glass薄膜随温度变化规律与理论模拟计算的趋势吻合;其温度-透过率曲线“突变”特性优于旋涂法制备的薄膜;可见光的微结构衍射图样类似光栅衍射图样,表明此种薄膜和微结构制备方法可行。研究结果可应用于防护涂层制备和微结构光学调控领域。
Vanadium dioxide(VO_(2))has a phase transition between the high-temperature metal state and the low-temperature semiconductor state,accompanied by significant optical property changes.However,the applicability of pure VO_(2) is limited by the transition temperature at 68℃.Ion doping is an effective method to effectively reduce the VO_(2) phase transition temperature,and W6+doping can reduce the VO_(2) phase transition temperature to 20~30 K/wt%.The dual-interface self-assembly method based on nanomaterials is environmentally friendly and simple to operate,and has the potential of large-scale production.In this study,W_(x)V_(1-x)O_(2)/glass films were prepared by bi-phase interfacial self-assembly method.Under hydrothermal conditions,pure W-doped VO_(2)(B)nano-powder was synthesized by hydrothermal crystallization using oxalic acid,tungstic acid and VO_(2) as raw materials,and then the crystalline transformation from VO_(2)(B)to VO_(2)(M)powder was realized by annealing process.The W_(x)V_(1-x)O_(2) nano-solution was synthesized by ultrasonic mixing of VO_(2) nano-powder with tungsten(W)atom ratio of 0%,1%,2%and 3%,high purity anhydrous ethanol and Polyethylpyrrolidone(PVP,concentration of 98%)at 1∶1∶28 weight ratio.W_(x)V_(1-x)O_(2)/glass film samples with tungsten concentration of 0%,1%,2%and 3%were prepared by vacuum silicone(Polydimethylsiloxane,PDMS)coated with self-made Polystyrene(PS)mold and nano-sized tungsten-doped vanadium dioxide solution added with surfactant on glass substrate,respectively.At the same time,the capillary flow movement and film formation process at the liquid/solid dual phase interface,as well as the double“coffee ring”pattern were directly observed.The complex dynamic change process of liquid-solid-gas system follows the laws of fluid dynamics and thermodynamics.On the basis of preparing W_(x)V_(1-x)O_(2) film at the bi-phase interface,Polyethylene(PE)wire with diameter of 1μm was added into the mold,and the microstructure of W_(x)V_(1-x)O_(2) film was fabricated by a simpl
作者
周杨洋
姜佳彤
张笑然
田梦杰
董博文
朱亚彬
ZHOU Yangyang;JIANG Jiatong;ZHANG Xiaoran;TIAN Mengjie;DONG Bowen;ZHU Yabin(Department of Physics,School of Physical Science and Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2024年第4期198-208,共11页
Acta Photonica Sinica
基金
国家大学生创新创业训练计划项目(No.220171013)。
关键词
薄膜
微结构
掺钨二氧化钒
双相界面自组装
光学透过率
衍射图样
Film
Microstructure
Tungsten-doped vanadium dioxide
Dual-phase-surface self-assembly
Optical transmittance
Diffraction pattern
