Preparation Of Blue Electrophoretic Particles

The electronic papers have become a most appealing application.Realization of chromatic E-paper is highly required and attracts much attention.The realization of color imaging in an electrophoretic display is based on the tricolor?red,blue,and green?theory of reflex light.In this thesis,we focused on the preparation of blue particles,which is one of the essential colors to produce chromatic electrophoretic particles.Firstly,the silica nanoparticles were prepared through a sol-gel process in reverse microemulsion combined with solvent-thermal treatment,then CoAl₂O₄ were coated onto silica nanoparticles to obtain blue CA/S nanoparticles.The size of silica nanoparticles were obviously affected by the ratio of water to surfactants???,the ratio of water to silicane?n?.With increasing of the values of?and n,the average diameter of silica nanoparticles increased and then decreased.In the coprecipitation of CoAl₂O₄ onto silica nanoparticles process,the influences of the parameters such as effect of sol temperature,the ratio of Co²⁺to Al³⁺,reaction time and water dosages on the structure of CA/S were studied.The sol temperature affected the react speed;the CoAl₂O₄ dosages affected obviously the color of samples;CA/S calcined at 1000^oC owned better bright blue color;however,the prepared CA/S showed unnegligible sinter problem.Secondly,the CoAl₂O₄-SiO₂ blue nanoparticles?CAS?were prepared through a sol-gel process in reverse microemulsion,then after surface modification with triethoxyvinylsilane and ionic liquid monomers,the blue silica nanoparticles coated with ionic liquid polymer?PIL/CAS?were obtained.For the preparation of CAS,the sol time,gel time and CoAl₂O₄ dosages affected obviously the structure and color of CAS.The samples prepared with sol time=75 min,gel time=30 min,w?CoAl₂O₄?=20%obtained beautiful bright blue color.After surface modification with ionic liquid monomers,the spherical PIL/CAS were obtained.With the monomer dosages increasing,the density of PIL/CAS decreased.