Study On Preparation Of Cellulose Fibre/Conducting Polymer/Silver Composite By One Step Reaction Approach

Cellulose fiber/polypyrrole/silver and cellulose fiber/polyaniline/silver composites by one step method were prepared in this paper. The SEM and EDX were used to characterize the composite. Besides studied the conductivity and antibacterial activity of composite, the factors affecting the conductivity and antibacterial activity of composite, including the types of conductive polymer, doping acid and process conditions were also discussed.By analyzing the results of SEM and EDX, silver was proved to exist on the surface of cellulose fibre/polypyrrole/silver. It was proved by antibacterial performance test that the composite material had great inhibitory effect on the bacteria such as Escherichia Coli, Staphylococcus Aureus and Bacillus Subtilis, especially for Escherichia Coli and Staphylococcus Aureus, while the composite without silver nitrate also had some antibacterial activity.The dosage and adding time of silver nitrate were discussed for the conductivity and antimicrobial activity. The results showed that the addition of silver nitrate had no effect on conductivity of the composite, although it could improve the antibacterial activity. The optimal dosages of silver nitrate for the preparation of cellulose fibre/polypyrrole/silver composite and cellulose fibre/polyaniline/silver composite were0.01g and0.005g, respectively. The adding time of silver nitrate had no contribution to the conductivity and antibacterial activity of the composite. In order to facilitate the operation, silver nitrate could be added at the beginning of the reaction.The ratio (wt%) of pyrrole monomer to cellulose fiber was changed to study the effect on the conductivity and antibacterial activity of cellulose fibre/polypyrrole/silver. It was confirmed that the conductivity and antibacterial activity were better with larger ratio and it could be best when the ratio was0.5:1.Ammonium persulfate was utilized as oxidant and the effect of the ratio (mol%) of reactant to dopant on the conductivity and antibacterial activity of cellulose fibre/polypyrrole/silver was studied. It was demonstrated that the conductivity was greater in certain range while the antibacterial activity was hardly varied with increasing the ratio of ammonium persulfate to pyrrole monomer, and the conductivity and antibacterial activity were best when the ratio of ammonium persulfate to pyrrole monomer was1.5:1. PTSA (p-toluenesulfonic) and SSA (sulfosalicylic) were used as dopant, respectively, and the conductivity and antibacterial activity were measured. The results showed that the conductivity could attain better when using SSA as the dopant to prepare cellulose fiber/polypyrrole/silver composite. The conductivity of the composite could reach8.5S/m when the concentration of SSA was0.1mol/L. In contrast, the addition of dopant had no effect on the antibacterial activity of the composite.When the dosage of silver nitrate was0.05g, aniline/fiber mass ratio was1.5:1, the mass ratio of ammonium persulfate to aniline was3:4, and SSA concentration was0.3mol/L, the conductivity and antibacterial activity of cellulose fiber/polyaniline/silver composite were best.Compared with cellulose fiber/polypyrrole/silver composite and cellulose fiber/polyaniline/silver composite, it was found that cellulose fiber/polypyrrole/silver composite had better antibacterial activity and conductivity while its environmental stability and strength were poor.