Preparation And Study Of Cellulose Based Light Functional Materials With High Haze And Light Transmittance

Light management film with high transmittance and variable haze always is an essential component for many optical or electronic devices.At present,the common high haze materials are mainly synthetic polymers which are difficult to degrade,such as PMMA,PET,PC,etc.The environmental problems caused by e-waste are becoming increasing serious.Therefore,the development of biodegradable optical management functional materials based on natural polymers has been widely concerned.This paper aims to understand the essential properties of high haze and high transmittance of materials based on the scattering theory,and explored the preparation methods of high transparency and high haze materials.On this basis,the inorganic/polymer hybrid,all natural components,all cellulose components materials with high haze and high optical transmittance were designed and developed.Specifically,this dissertation includes the following three parts:(1)Determination of the size of Mie scatter particle.The essential reason for the high haze and high transmittance of optical materials is that the incident light scatters on the surface or inside of the materials,and the scattering type is mainly Mie scattering.In this chapter,the main factors of high haze and transmittance of materials are analyzed and understood from Mie scattering theory.The size of the Mie scatter partical in the visible light range is determined by the range of the scale parameter α in the Mie scattering theory.The haze optical films were prepared by the composite of commercial silica microspheres and cellulose,and the experimental and theoretical results were compared.The experimental show that the change of optical properties of the composite films is in accordance with the Mie scattering theory,and the cellulose/silica-sphere composite film with light transmittance>80% and haze>93% is finally obtained by adjusting the size,incorporation quality of silica microspheres and change the preparation method.The related results lay a theoretical foundation for the further preparation of high haze and high transmittance membrane materials.(2)Preparation of cellulose/chitosan all-natural-component film with high haze and high light transmittanceBased on the results of the previous part,highly transparent(85%)cellulose/chitosan composite film with tailored transmission haze from the degradable natural polymers was prepared in this chapter.The experimental investigations indicate that the haze can be precisely regulated in wide range(1-93%)by controlling the size and addition amount of scatterers(chitosan powder),coagulating bath and drying process while it has a little influence on the transparency of the composite films.Then we intuitively show the application potential and prospect of cellulose/chitosan composite film in privacy protection,anti-glare and new-concept of no main lighting decoration.In addition,compared with the traditional methods such as viscose method,the preparation process of composite membrane uses less harmful substances and conforms to the core concept of green chemistry.More importantly,it is completely compatible with the existing automatic continuous lines for large-scale production of cellulose film and can be easily extended to other degradable binary systems(e.g.,cellulose/lignin),which provides an available option for biodegradable optical materials(especially the optical films)to be utilized in commercial optoelectronic.It openes a door for large-scale applications of the cellulose-based optical materials.(3)Study on the preparation of high haze all-Cellulose film.In this chapter,the ability of ionic liquid to dissolve cellulose is adjusted by controlling temperature to make cellulose partially dissolved,in which the dissolved cellulose acts as the matrix material,while the undissolved part keeps the original particle shape of cellulose and acts as light scatterer.Through this method,we have prepared high haze and high transmittance cellulose film with the transmittance and haze higher than 80%.At the same time,we found that by adjusting the ratio of ionic liquid and co-solvent DMF,the mixed solvent can dissolve microcrystalline cellulose at room temperature.This is of great significance to the optimization of the preparation conditions of all-cellulose optical film and the development of the room temperature dissolving system of cellulose.