Solvothermal Synthesis And Modification Of Chromium Oxide Hollow Microspheres And Ink For Inkjet Printing

Chromium trioxide(Cr₂O₃)is a kind of functional material with special visible and near-infrared spectral characteristics.Its spectral properties are similar to those of green vegetation,and it is widely used in the field of camouflage.However,the current production mode of camouflage coating,which uses Cr₂O₃ as functional coating to simulate green vegetation,is backward,and it needs a production method ink-jet printing to meet the current battlefield demand for digitalization and information.Ink is the key to the application of ink-jet printing technology.Inorganic pigment(hereinafter referred to as pigment)ink has the difficulty of pigment particle refinement,which is easy to block the nozzle;because of the deposition and agglomeration of pigment particles,the ink is stratified and deteriorated.Although there are mature researches on Cr₂O₃ based green vegetation simulation coating,there are few reports on the research of using Cr₂O₃ as pigment to prepare ink and using ink-jet printing to produce coating.Cr₂O₃ micro nano particles,surface modified Cr₂O₃ micro nano particles and Cr₂O₃hollow micro nano spheres were synthesized by solvothermal method.The ink was prepared by surface modified Cr₂O₃,and the pattern was prepared by ink-jet printing,and the spectral characteristics of the pattern were explored.The paper is divided into the following four parts:(1)solvothermal preparation of Cr₂O₃ nanoparticlesIn the experiment,Cr(Ac Ac)₃ was used as chromium source,ethanol as solvent,and Cr₂O₃ micro nano particles were prepared by solvent method.By controlling the experimental temperature,the dispersed and stable surface modified Cr₂O₃ colloids were successfully prepared at 180?and 190?(the average particle size was 0.60?m and0.63?m respectively);Cr₂O₃ hollow micro nano spheres were prepared by solvothermal templet free method;by adding solvent and changing the temperature The ratio can effectively control the particle size of the product.(2)characterization of surface modified Cr₂O₃FTIR,Raman,TG and XRD were used to characterize the surface modification of Cr₂O₃.The stability of the colloidal product was tested.The simulated natural deposition for 8 years showed that the surface modified Cr₂O₃ nanoparticles dispersed stably in polar solvent ethanol and settled slowly.(3)preparation and properties of Cr₂O₃ inkCr₂O₃ ink with viscosity,surface tension and settling stability meeting the requirements of ink-jet printing was prepared with Cr₂O₃ colloid product modified on the surface as raw material.The settling stability of prepared ink was proved to be good by simulating the natural settling test for 2.5 years.(4)study on the optical properties of printing patterns with Cr₂O₃ inkThe digital Cr₂O₃ ink pattern is obtained by using jetlab II printer.The edge of the pattern is clear,accurate and of good quality.The similarity of the visible near infrared reflectance spectrum between the pattern and the fresh green leaves is 0.9043,which proves the feasibility of preparing Cr₂O₃ simulated green vegetation coating by inkjet printing technology.