The Study On The Sol-gel Technology And Its Application On Electromagnetic Shielding Fabrics

This paper puts forward a kind of activation method for chemical plating which is based on sol-gel technology,forming active centers on the surface of textile to initiate chemical plating nickel successfully.The traditional technology which includes etching,sensitization and activation process has been improved by this activation method and the amount of precious metals has also been reduced.The activation layer of thin-precious metal has much better catalytic properties.applying to polyamide fabric,the metallized textile with high fastness and excellent electromagnetic performance can be acquired.This pretreatment process has highlighted the advantages and broad prospects.Firstly a sol substrate was deposited onto the surface of nylon fabric and transformed into gel. Then there could be a Pd layer with higher catalyst ability on the surface after dipped in the activation solution. Orthogonal and single-elemental experiments were used to study the formula of the activation process and the best conditions and to analyze the effects of various factors on the activation process. Regarding the surface resistances of the electromagnetic shielding fabric and the mass-increase rates as judging evaluation, there came out the optimum conditions: concentration of APTES 2%, concentration of ethanol 28.6%, concentration of acetic acid 0.714%, time 30 min; concentration of chloride palladium 40 mg/L.Activation process: concentration of palladium chloride 40mg/L, treatment temperature 25℃, treatment time 30min～40min.The polyamide fabric was used as substrate, Firstly supported complex compound catalyst was formed based on the large molecular volume and special hydroxyl groups of the P-CD,thenβ-CD with nest-site was anchored on fabric by sol-gel method.A Pd-β-CD catalysis film was deposited onto the surface of nylon fabric, and there could be a layer with higher catalyst ability on the surface after dipped in the activation solution. Orthogonal and single-elemental experiments were used to study the formation of the substrate layer and the optimum conditions,and analyse the effects of the various factors on the activation process. Judging the activation effects on the basis of the surface resistances for the electromagnetic shielding fabric,and it came out the optimum conditions: concentration of GPTMS 18 g/L, concentration of TEOS 20g/L, concentration of ammonia 3.6%, concentration of ethanol 26.7%, time 30 min; Activation process: concentration of palladium chloride 40mg/L, treatment temperature 25℃, treatment time 30min～40min.The flexible substrate after the best conditions of the activation process was characterized by XRD,SPM, SEM ,UV-Vis. The XRD spectrogram of activated substrate indicated that the palladium membrane was formed on the flexible substrate;The SPM was used to visualize the film structure,the particle size and morphology of the Palladium grain, SEM and micro-image can be used to supported this conclusion; and the model of complexingβ-CD with Pd was characterized by ultraviolet-visible spectroscopy.The chemical-plating fabrics were characterized by strength, anti-UV performance, corrosion resistant properties, conductivity performance, thermostability performance, rubbing-resistant properties and fastness. The results indicated that the electromagnetic shielding material processed by this activation method had excellent anti-UV performance, sufficient corrosion resistance, conductivity, thermostability, and also good binding fastness.