| Presently, the increasingly important energy crisis and environmental issues,especially energy-saving building materials, provide a favorable opportunity forincorporating of the important new and old subject of nano-technology, energy-savingtechnology, engineering technology and etc, also crossing the major disciplines ofphysics, chemistry, materials science etc. Smart energy-saving nanocompositematerials are starting a major research direction from this high-tech level.Energy-saving smart materials because of it respond to smart characteristics of theexternal environment. Through nano-materials structures and the function ofcomposite and collaboration of these materials, smart energy-saving system by theoutfield factors most of the thermal field controlling of optic and thermal responsecan be achieved, which can conform to energy-saving demanding, especiallyenergy-saving building demanding. In this work, thermochromic smart window hasprepared by nanocompsites system through thermochromic materials and solarthermal conversion materials of function collaboration and interfacial couplings. Themajor contents as follows:1. Vanadium dioxide possesses of many crystalline phases, including tetragonalVO2(M), rutile-type VO2(R), metastable monoclinic VO2(B), VO2(A), etc.Different experimental methods have been explored in this paper. Three dimensionaluniform flower-like VO2(B) hierarchical microstructures have been synthesized on alarge scale through a green reaction route. The flower-like VO2(B) microstructuresare assembled by many interleaving nanoplates which have the size distribution of2-5μm. Ethylene glycol not only was a solvent and reductive agent, but also played akey role in the fabrication of flower-like VO2(B) nanostructure. Control detailexperiments revealed that the formation of the flower-like VO2(B) was based on thefast nucleation-growth process. Flower-like VO2(B) hierarchical structures areunfavorable to form in the low reaction temperature. The different condition ofalcohol-water ratio has a significant impact on the reaction process of hydrolysis, reduction, condensation. The number of the hydroxyl plays significant function in thestructure of product. The3D hierarchical VO2(B) structure suggests that it is a morepromising material for application in lithium ion battery. Meanwhile, this facile,low-cost and novel route can also be extended to the preparation of other functionalmetal oxide materials. In addition, Monoclinic VO2(M) nanoparticles can beobtained by a sample thermolysis in an atmosphere of air method with lowtemperature, which exhibit high crystallinity, excellent thermochromic property andhigh yield. A large-scale and low cost synthesis method has been prepared for VO2(M).2. Different morphology of PbS has been controllable synthesized by differentexperimental reaction condition. A few minutes preparation of PbS nanocubes withsize distribution of50-80nm and uniform morphology and high crystallinity havebeen found. Experiments with different lead acetate concentrations are carried out anddifferent morphology of PbS nanostructure appeared. Octahedral PbS nanocrystalswith the size distribution of140-170nm are prepared with the lead acetateconcentration of20mM. When the concentration of lead acetate increased to25mM,the shape of the obtained PbS dramatically changes from octahedrons to hexangularstars. When used UV-VIS (NIR) spectrophotometer to acquire the absorptionspectrum, nanostructure PbS display excellent light absorption property by comparingwith bulk PbS and carbon sphere. PVA-PbS-VO2(M) composite film can be preparedby casting film method. Using275W halogen lamp to simulated sunlight andemploying thermal infrared camera to imaging, the phase-transition temperature canbe achieved in the PVA-PbS-VO2(M) composite film. PVA-PbS-VO2(M) compositefilm characterize by DSC, which shows the reversible metal-insulator transition ofVO2(M). |
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