High-Adhesion Ag Film with Enhanced Electromagnetic Shielding Performance via Post-Treatment of a Polydopamine Adhesive Layer

Low adhesion limits the application of the conformalmetal coatingbased on metal-organic complexing deposition (MOD) ink in electromagneticinterference shielding with an ultrathin thickness and excellent electromagneticshielding performance. Here, the mussel-inspired polydopamine (PDA)coating with double-sided adhesive characteristic was used to modifythe substrate surface, and a high-adhesion silver film was preparedby spin-coating MOD ink on the PDA-modified substrate. The surfacechemical bond of the deposited PDA coating was found to change withthe exposure time under air in this work, and three post-treatmentmethods were carried out on the PDA coatings, including exposure toair for 1 min, exposure to air for a day, and oven heat treatment.The influences of such three post-treatment methods of PDA coatingon the structure of the substrate surface, the silver film adhesionproperty, the electrical property, and the electromagnetic shieldingproperty were studied. The adhesion of the silver film was effectivelyenhanced up to 20.45 MPa by controlling the post-treatment methodof the PDA coating. The PDA coating was found to increase the sheetresistance of the silver film and to absorb electromagnetic waves.By optimizing the deposition time and the post-treatment conditionof the PDA coating, superior electromagnetic shielding effectivenessup to 51.18 dB was obtained with a thin silver film of 0.42 & mu;m.The introduction of the PDA coating improves the applicability ofthe MOD silver ink in the field of conformal electromagnetic shielding.

Automated summary

To address the issue of low adhesion in the conformal metal coating using metal-organic complexing deposition ink for electromagnetic interference shielding, a mussel-inspired polydopamine (PDA) coating with double-sided adhesive characteristics was used to modify the substrate surface. By controlling the post-treatment method of the PDA coating, the adhesion of the silver film was effectively enhanced, and superior electromagnetic shielding effectiveness was achieved with a thin silver film.