Study On Preparation Of Molybdenum Disulfide/Polystyrene Aqueous Nano-inks And Its Application On Inkjet Printing

Two-dimensional(2D)materials and their nano-inks have recently attracted much attention for their potential implementation in flexible electronics,biosensors,energy devices,and other fields.Liquid-phase exfoliation is one of the most important methods to prepare 2D material-based nano-inks.However,its preparation involves organic exfoliating solvents of high boiling point and biological toxicity,which greatly limited their application.Therefore,this paper studies the green preparation of MoS2 nano-inks obtained via liquid-phase exfoliation,using soap-free polystyrene(PS)latex and a ternary composite solvent consist of ethylene glycol/deionized water/ethanol.The MoS2 nanoflakes are stable within the aqueous solution due to the physical adsorption between nanoflakes and PS latex particles as well as the interparticle's electrostatic repulsion.The main research contents and conclusions include:(1)To investigate the effect of different types and ratios of ternary green composite solvents on the liquid-phase exfoliation of MoS2.The best volumetric ratio of exfoliation solvent was fixed at 2.5:2.5:1.0 of ethylene glycol/deionized water/ethanol.It was found that the use of negatively charged small-molecule surfactant effectively enhanced the exfoliation effect.Meanwhile,adding sodium dodecyl sulfate into the ternary green composite solvent increased the concentration of MoS2 nanoflakes from 0.03 mg/mL to 1.30mg/mL.(2)A new method for liquid-phase exfoliation of MoS2 nano-inks was developed using polystyrene latex particles as the stabilizer.At the same time,the influence of latex type and the related mechanism facilitating exfoliation between polystyrene latex and MoS2 was explored.It was found that both the physical adsorption of latex particle-MoS2 and the electrostatic repulsion of negatively charged latex particles were dominant in the exfoliation process.The concentration of MoS2 nano-ink assisted by negatively charged latex was up to 4.80 mg/mL.(3)To study the application of polystyrene latex-MoS2 exfoliated solution as the aqueous nano-inks for inkjet printing.The nano-inks possessed good stability,low viscosity,and an inkjet printing precision of 10 ?m.The functional particles encapsulated by "graphene-MoS2/polystyrene-graphene" with good fluorescence and electrical conductivity can be manufactured by "autoperforation" nano-processing technology.This study provides a new path for the green and efficient preparation of 2D material-based nano-inks,and can be applied in the micro-or nano-processing fields such as microcircuit printing and microparticle device fabrication.