Preparation Of Silver Citrate Particle-free Ink And Study On Coating Film Propertie

Flexible printed electronics is an emerging field that combines traditional metallization techniques with flexible substrates to produce lightweight,conductive films.This technology utilizes different materials as conductive phases,offering advantages over traditional hard indium tin oxide technology,which requires rare and expensive indium metal.Conductive ink is the core of this technology,with most of the conductive inks used in the market being particle-free inks.However,traditional particle inks suffer from agglomeration due to high sintering temperatures,making them unsuitable for storage and use.In contrast,non-particle inks have a lower postprocessing temperature,allowing for films with excellent conductivity.This study aimed to prepare particle-free silver-based ink using silver citrate as a precursor,n-butylamine as a complexing agent,and ethanol and isopropanol as organic solvents.The film-forming properties of the ink were investigated,and the sintering temperature and time were optimized to achieve the optimal conductivity.The study also examined the effect of alkyl chain length,spatial position structure,and different types of amine ligands on the decomposition temperature,film morphology,and conductivity of the ink.The researchers successfully prepared particle-free silver-based ink and spin-coated it onto polyimide films to form conductive Ag films.The optimized sintering temperature and time resulted in films with excellent conductivity(20.81μΩ·cm).Straight-chain amines were more stable in coordination with coordinating atoms than branched-chain amines due to spatial hindrance.The length of the alkyl chain affected the decomposition temperature of the ink,with longer chains increasing the boiling point of the amine ligand.Inks with lower decomposition temperatures were more likely to form silver nanoparticles of varying sizes.The activation of amine ligands during silver ion reduction varies with alkyl chain length.Longer alkyl chains result in decreased activation of the ligand.Poorly activated,long-chain amines exhibit lower release efficiency,leading to nucleation inhibition and a relatively narrow distribution of silver nanoparticle sizes.These findings demonstrate a relationship between alkyl chain length and the activation of amine ligands,providing insights into the mechanism of silver ion reduction and the formation of nanoparticles.The Ag films sintered with n-butylamine ink exhibited good tensile,bending,and adhesion properties as sensing elements.The Ag film’s tensile strength reached 95.195 m Pa,and the nominal tensile strain was about 35 % higher than that of the polyimide film,improving the film’s deformation ability.After the film was bent multiple times,its resistance hardly changed,and there was no obvious peeling,demonstrating good adhesion properties.This study’s findings suggest that non-particle silver-based ink is suitable for use in flexible printed electronics technology.