Electroless Silver Plating On The Polyester Fibers And Polyamide Fibers Modified By 3-Mercartopropyltriethoxysilane

Silver-coated fibers were developed with functional properties including excellent conductivity, anti-static property, electromagnetic shielding and antimicrobial activity. This paper put forward to a kind of pretreatment method for chemical plating which is based on MPTES gel technology and it is scouring-free, etching-free, sensitization-free or activation-free. When this technology is used to produce PET silver-coated fibers, the whole process requires only two steps: PA-MPETS gel modification and silver electro-less plating. When it is used to PA6 silver-coated fibers, the pretreatment of PA fibers includes two steps:carboxylation and mercaptolation. This MPTES gel technology can improve the whole system to be more energy-and time-saving. The silver-coated fibers, in the form of blended fabric, enjoy huge market potential as antistatic, anti-microwave, and antibacterial materials. And this two-step method has offered a green and convenient approach to meet the requirement of silver-coated PET and PA6 fibers.Antibacterial polyester (PET) fibers with high electric conductivity were introduced by pretreatment-free electro-less silver plating in this study. The PET fibers were modified with the PA-MPTES gel before silver coating. The optimum conditions for this step were studied through the orthogonal and single-elemental experiments. Regarding surface resistance as main factor, we obtained the optimum conditions:amides 1.9%(w/w), MPTES 8.5%(w/w), H2O 7.5%(w/w), ethanol 13%(w/w) and the volume ratio of amides solution and MPTES solution 17:8. Using single-elemental experiments, we obtained the optimal PA-MPTES gel modifying process condition:the modification time 40min,the modification temperature 40℃and the drying temperature 100℃.The PET fibers were successful modified by PA-MPTES gel, which was proved by the ATR-FTIR spectra, Raman analysis, energy dispersive X-Ray (EDX) analysis and thermo-gravimetric (TG) analysis, respectively. Uniform and compact silver-coated film was found on the surface of PET fibers, evidenced by scanning electron microscopy (SEM). With 16% silver loading, the results indicted that silver-coated fibers have high electric conductivity (2.66Ω/cm).In addition, two other types of silver-coated fibers were prepared with other methods, such as traditional multi-step approach and only siloxane modification method. The comparisons between them were carried out in the tests of electrical conductivity, washing fastness and antibacterial property, respectively. The silver-coated fibers based on amide-siloxane modification can endure the ultrasonic washing challenge when compared to the other two approaches, with higher conductivity and strong antimicrobial activity against Escherichia coli. Meanwhile, the results of SEM analysis also demonstrated that the silver-plated layer produced by PA-MPETES gel technology is smoother and more compact than the other two samples, in agreed with the results of test of conductivity.Multi-functional silver-coated PA 6 fibers were introduced in this paper, with the properties of excellent conductivity, antistatic ability and high washing fastness. This time-and-energy saving pretreatment included two steps:carboxylation and mercaptolation. The optimum conditions for these steps were studied through the orthogonal and single-elemental experiments. By using the strength and the content of carboxyl groups as the criteria, there came out the optimum conditions for the carboxylation step: treatment temperature 70℃, time 60min, concentration of formic acid and acetic acid both 111.1 g/L. Regarding the surface resistance before and after ultrasonic washing, we obtained the best conditions for mercaptolation: temperature 40, time 3 h, the concentration of ethanol, ammonia solution, MEPTS was 850ml/L, 24ml/L and 14.28g/L, respectively. The PA fibers were successfully modified by MPTES, provided by Raman analysis, Energy Dispersive Spectrometer (EDS) and thermo-gravimetric (TG) analysis. Compact and even silver layer was found on the surface of PA fibers, evidenced by the results of Scanning electron micrographs. The surface resistance of silver-plated fibers was 5.67Ω/cm and 6.89Ω/cm before and after ultrasonic washing, respectively. Even after five times ultrasonic washing, the surface resistance of silver-plated fibers was 33.48Ω/cm, proving that these PA6 silver-coated fibers can endure at least five times ultrasonic washing.