Durable cellulose paper by grafting thiol groups and controlling silver deposition for ultrahigh electromagnetic interference shielding

Abstract

Electromagnetic interference (EMI) shielding paper with durability and high effectiveness is of significant importance to long-term service for preventing EMI pollution. Herein, we report a practical method for preparing cellulose paper/Ag composite with outstanding durable and ultrahigh EMI shielding performance by electroless silver plating. The silver deposition process, the surface morphology, the silver content and conductivity of the composite can be controlled by varying the amount of N-acetyl-L-cysteine (NAC) grafted onto the cellulose fibers and ammonia amount for silver-ammonia complex formation. Moreover, the grafted NAC with thiol groups on cellulose can enhance the adhesion between silver and cellulose paper, meanwhile, NAC as the reducing agent can result in a more complete flower-shaped silver structure and reducing the reflection of electromagnetic waves in silver layer. The composite exhibited excellent conductivity, EMI shielding effectiveness (SE) up to 106 dB and outstanding durability. After 10,000 bending times and 60 abrasion cycles respectively, the electrical resistance of the composite only increased from 0.030 Ω/sq. to 0.041 Ω/sq. and 0.050 Ω/sq., and the EMI SE decreased to 102 dB and 105 dB.