Preparation And Properties Of Silver Nanowire Based Conductive Ink

With the development of portable electronic devices and flexible wearable electronic devices,traditional indium tin oxide?ITO?materials have gradually failed to meet people's needs due to their high brittleness.As one-dimensional conductive material,silver nanowires?AgNWs?have excellent electrical conductivity,thermal conductivity and flexibility,and are considered to be the best ITO replacement material.At present,Meyer rod and spray coating methods are considered to be the most likely to achieve mass production in the preparation process of AgNWs flexible transparent conductive film?AgNWs-FTCFs?.The emerging inkjet printing electronics technology provides an idea for the preparation of high-precision,controllable patterned conductive films.As the basic material of conductive pattern,conductive ink is the key factor and bottleneck to the development of printed electronics technology,and directly affects the performance and quality of electronic products.In this paper,firstly,the research progress of AgNW-FTCFs and inkjet printed conductive ink are reviewed.Secondly,AgNWs are synthesized by polyol method and the controllability of AgNW size is studied by ultrasonic induced scission.Then,with self-made and commercial AgNWs as raw material,the AgNW-FTCFs were prepared by Meyer bar and spray coating methods and their properties were studied.Finally,the preparation of the inkjet printing AgNWs conductive ink and the inkjet printing conductive patterns are discussed.The specific works are as follows:?1?The effects of reaction time and temperature on the size of the AgNWs prepared by the polyol method and the ultrasonic time and power and the concentration and diameter of AgNWs on the scission length of AgNWs were studied.The results show that the length and diameter of AgNWs increase with the increase of reaction time and temperature,and the growth rate gradually increases with the increase of temperature.In addition,the length of AgNWs decreases with the increase of ultrasonic time and power,and decreases with the decrease of concentration and diameter.However,these has no significant effect on the diameter.?2?We prepared AgNW-FTCFs by Meyer bar coating.The effects of the length,concentration and amount of AgNWs on the photoelectronic properties and microstructure of the film were systematically investigated.The thermal properties and flexibility of the films were also disucssed.The results show that the comprehensive photoelectric performances of the conductive film increase with the increase of the length of the AgNWs.At high concentration,the film has poor morphology but good electrical properties.At low concentration,the film formation uniformity and photoelectric performance are better.With the decrease of the sheet resistance?Rs?and the increase of the DC voltage,the stable temperature and the thermal uniformity of the film gradually increases.For the AgNWs conductive film produced with the length of15.49?m,the concentration of 2 mg·mL^-1 and the amount of 0.14 mL,the optical transmission at 550 nm is 90.4%with R_s of 61.5??sq^-1,the haze value of 1.04%,and the non-uniformity factor of 0.23,which means the uniformity is good.?3?We prepared AgNW-FTCFs by spraying.The effects of length,concentration and amount of AgNWs on the optoelectronic properties were systematically investigated.The results show that the comprehensive photoelectric performance of the conductive film increases with the increase of the length of AgNWs.However,in terms of the fabricating process,the nozzle is very prone to be blocked during spraying process in the conditions of the long length and high concentration of AgNWs.While,the droplet splash phenomenon and the coffee ring effect are prone to occur in the condition of the low concentration.Appropriate length and concentration and amount of AgNWs are favorable for obtaining good photoelectric properties of AgNWs-FTCF.For the AgNWs conductive film produced with the length of 9.48?m,the concentration of0.9 mg·mL^-1 and the amount of 2.3 mL,the optical transmission at 550 nm is 85%with R_s of 93.5??sq^-1 and the non-uniformity factor is 0.55.?4?The inkjet printing AgNWs conductive inks are prepared with AgNWs as the conductive component,deionized water as the solvent,diethylene glycol as the wetting agent,and isopropanol as the viscosity and surface tension modifier.The results show that the inkjet printing AgNWs conductive ink is suitable for printing when the AgNWs dispersion:deionized water:diethylene glycol:isopropanol=19.25:40:5:30,the viscosity is 4.9 mP·s,the surface tension is 28 mN/m,and the ink density is 1.1 g·cm^-3.The AgNWs conductive patterns were prepared by microplot II nano material deposition system,but the clogging phenomenon in the printing process and the coffee ring effect at the beginning of the line were serious,which needs further improvement.