The Study About The Thermo-Reflective Property Of VO2 Thin Film On Glass Fiber Cloth

VO2 has been widely investigated because of its low phase transition temperature at 68?.Its some properties would happen suddenly changing after the phase transition,such as its conductivity,refractive index and flux,which result in its potential application of thermoelectric materials,thermooptical materials and thermomagnetic materials.The work presented here used sol-gel preparing VO2 thin film on glass fiber cloth.The results are as follow:1.Using the method sol-gel,the VO2 thin film on glass fiber cloth was prepared by controlling the dipping times.The VO2 thin film on glass fiber cloth has a phase transition temperature at 38?,which is much lower than pure VO2.The reason of it happened mainly is the existence of V5+,whose ion content is about 4%,in V02 thin film after the sol-gel method.Besides,the usage of glass fiber cloth as supporter has the advantage of softy when comparing with the sapphire,mica sheet and glass sheet.And the vertical weaving of glass fiber cloth makes incident light on its surface diffuse,which result in its angle-independent property.2.The VO2 thin film on glass fiber cloth prepared by sol-gel method not only inherits the thermo-reflective sudden changing property from V02,but inherits the angle-independent and softy property from glass fiber cloth.Thus,it can apply in greenhouse playing the role of temperature regulation.When temperature inside greenhouse is higher than 38?,the reflection on the surface of VO2 thin film is low,decreasing the heat return back to greenhouse,which result in the decreasing of temperature and vice versa.3.The proportion of leaching solution is H2O2 200ml/L,HF 400ml/L and HNO3 50ml/L.The optimum leaching time is 60s.The VO2 thin film on glass fiber cloth after 60s leaching has the property of reflected intensity-temperature linear changing,which can apply in temperature fast measuring because the phase transition of VO2 is ultrafast.