Research On Green Synthesis Of Nano-silver Functionalized Fabrics With Dyestuff Plant Extracts

The natural plants madder root and mountain gardenia are common traditional Chinese herbal medicines,and also common raw materials for plant dyes.The crocetin and alizarin in the extract belong to yellow and red natural dyes.Due to its small particle size and large specific surface area,nano-silver has higher antibacterial activity than silver ions,and is often used for antibacterial finishing of natural fibers.The preparation method of nano silver is usually achieved by reducing silver nitrate with a chemical reducing agent.However,the commonly used chemical reducing agents are too strong,the size of the prepared nano-silver is not easy to control,and the residue will cause environmental pollution.Based on this,This topic uses madder root and mountain gardenia extracts as dyes,reducing agents and stabilizers to reduce silver nitrate to prepare nano-silver and finish it on cotton and wool fabrics.It achieves the purpose of integrating dyeing and antibacterial and deodorizing functions,and improves its antibacterial properties while imparting color to the fabric.The content of this subject is mainly divided into three parts.(1)The gardenia yellow extract synthesizes nano-silver to finish cotton fabric.The effects of single factors such as p H value and Ag~+concentration on the reduction of silver nitrate by gardenia yellow extract and the finishing of cotton fabrics were explored.The solution and finishing fabric surface nano-silver deposition state,anti-ultraviolet performance,antibacterial properties and washing resistance were tested and characterized.The experimental results show that the optimized process of reducing silver nitrate with gardenia yellow extract is:Gardenia yellow extract diluted 1:5,silver nitrate concentration 1 m M,temperature 80℃,reaction time 30 min,p H=10;The particle size of the reduced nano-silver is about 20 nm,and it is uniformly and stably dispersed in the solution;The optimized finishing process is:Dyeing time 60 min,dyeing temperature 70℃,dyeing p H=8,after finishing,the surface of the fabric is bright yellow and has good washing resistance and UV resistance.Its UPF=48.5 and UVA=2.07%,nano-silver is fixed on the surface of the fabric with intermolecular force;After finishing the fabric,the bacteriostasis zone of E-coli and Staphylococcus aureus is greater than 7 nm,has good antibacterial properties,and increases with the increase of the amount of silver nitrate.However,after finishing the fabric after 10times of washing,the inhibition zone is slightly reduced,and its antibacterial and washing resistance needs to be improved.(2)The madder root extract finishes the cotton fabric pretreated with Ag~+.The effect of different Ag~+treatments on the dyeing of cotton fabrics with madder root extract was compared,and the effect of single factor on the finishing effect of madder root extract finishing the cotton fabrics pretreated with Ag~+was explored,and the finishing process was optimized through orthogonal experiments.The experimental results show that the dyeing process of Ag~+pretreated cotton fabric has the best effect,the dyed fabric has the largest K/S,and the surface of the fabric sample is grayish brown.The optimized process conditions are as follows:the amount of silver nitrate is 1 m M,the pretreatment time is 40 min,the pretreatment temperature is 80℃,the dyeing time is 50 min,the dyeing temperature is 70℃,and the dyeing p H=5.The dyed fabric has excellent UV resistance,with UPF=219.32 and UVA=0.33%;After dyeing,the bacteriostatic zone of the fabric is larger than 7 mm,which has antibacterial property,and the antibacterial effect is best when the amount of silver nitrate is 5 m M.(3)The madder root extract synthesizes nano-silver finishing wool fabric.The best process for reducing silver nitrate with madder root extract and the effect of different finishing processes on the antibacterial properties of wool fabrics were explored.And test and characterize the nano-silver deposition state and antibacterial properties on the surface of the solution and the finished fabric.Experimental results show:The optimized process for reducing silver nitrate with madder root extract is:The concentration of silver nitrate is 3 m M,the reaction time is 60 min,the reaction temperature is 80°C,and the p H of the reaction solution is about 9.The synthesized nano-silver has a particle size of about 28 nm and does not agglomerate in the solution.The wool fabric finished with the nano-silver solution prepared by reducing silver nitrate with madder root extract showed antibacterial properties,and the antibacterial effect was best when the amount of silver nitrate was 2 m M.