Preparation Of Polymer Dispersed Liquid Crystal Device Based On Interference/Gradient Exposure

Liquid crystal materials are widely used in LCD now.But with the development of display technology,the market share of LCD is slowly replaced by OLED technology due to the disadvantages of the LCD.Based on this background,this paper used PDLC technology to realize the application of liquid crystal materials in non-displays field.However,the liquid crystal droplets in the traditional PDLC films are randomly distributed,so the polymer structure is not controllable.In order to obtain polymer with controllable structure,we used periodically distributed ultraviolet light to prepare PDLC films.In this way,through phase separation,the polymer polymerized in the region with high light intensity,and liquid crystal precipitated in the region with low light intensity,thus realizing the periodic polymer / liquid crystal structure.The main contents of this paper are as follows:Firstly,we used the HPDLC technology to realize the high reflectivity DBR films.This method is simple,fast,and inexpensive compared to traditional techniques.At the same time,it can realize selective high reflection of specific wavelength by changing the interference angle.After that,we also used a patterned photomask to realize reflective holographic exposure in the liquid crystal cell and obtained a holographic patterned DBR film.This holographic film can be used in anti-counterfeiting and other fields.Since the prepared DBR film is hollow and nanoporous,which means its specific surface area is large.So the liquid can quickly enter into it,which causes the refractive index of the air layer to change accordingly and makes the reflection spectrum change.In liquid sensor,this kind of film can realize high-sensitivity visualization and rapid detection.Then,we used gray-scale photomask and PSCOF technology to prepare liquid crystal microlens array conveniently.After that,we characterized the morphology of microlens array.The orientation of liquid crystal was good and the structure was uniform and flat.We then sat up an optical path to detect the focusing and imaging effects of the microlens array under polarized light.Through CCD observation,the focusing and imaging effects were good,and the uniformity was also good.Finally,by applying voltage to the microlens array,we observed its focus and imaging changed at different voltages.At the same time,we calculated the focal length change to see its electrical control.The results showed that it was tunable.This kind of microlens array has wide application prospects in 3D imaging and other fields.