The Preparation Of Microspheres With Micron Size And Infrared Wavelength Photonic Crystals

The optical structure of photonic crystals?PhC?can modulate the light-wave.It can modulate visible light,if it's photonic band gap located in visible light band.Similarly,if we prepare photonic crystals whose photonic band gap located in infrared band,then,we can achieve the modulation of infrared wave band.Unlike the former application where we use the structural color of photonic crystals to detect and sense,This paper we focus on the photonic crystals in infrared wave band,and broaden the application range of photonic crystals.The preparation of micro-size self-assembly units and the preparation of infrared photonic crystals with self-assembly are the prerequisite of the infrared photonic crystals'application,therefore we carry out experiment based on the two aspects.First of all,we synthesized a series of polystyrene and silica microspheres in micro size.In the process,we studied the influence of monomer,initiator,dispersant and solvent polarity on the size and morphology of polystyrene microspheres.And we tried the Stober method,Seed method,Velocity control method,Organic silane one step method and Coating method to synthesize the silica microspheres in micro size.Next,we prepared a series of infrared 2D-PhC and 3D-PhC with polystyrene microspheres and 2D-PhC of Cellulose,Titania and Tin Dioxide.As for the preparation of polystyrene 3D-PhC,the optimum condition is 60?,0.2wt.%and 3⁴ day.The optimum condition of 2D-PhC of Cellulose is Infiltration method with slide covering and dry under60?,and we found that the bore diameter will shrink about 200³00nm for Methyl cellulose,but the Carboxymethyl cellulose is not.Likewise,the bore diameter will shrink about 200nm for 2D-PhC of Titania and Tin Dioxide compared to polystyrene 2D-PhC.Then,we prepared a series of infrared silica 2D-PhC and 3D-PhC,and the special silica photonic crystals whose photonic band gap located in working band of Infrared detector.We use the vertical deposition method to preparation silica 3D-PhC,for the 1.5?m SiO₂,we choose alcohol under 60?or acetone under 40?as the preparation conditons;For the bigger silica microspheres,we choose alcohol/dibromomethane=3:1 under 60?as the preparation conditons.When we prepare infrared silica 2D-PhC,the silica microspheres should be hydrophobic treated first and the use the chloroform/alcohol=2:1 as the solvent.Besides,we treated the silica microspheres with high concentration of NaBH₄ and prepared silica 2D-PhC with coffee ring easily.Finally,we choose 1.5?m and 4.3?m SiO₂ microspheres to prepare the photonic crystals whose photonic band gap located in working band of Infrared detector,and these marerials can alter the Infrared radiation characteristics of objects.