A Study On The Applications Of Dopamine Used In Fabric Functional Modification

With the increasing awareness of environmental protection and the rising demand for functional textiles,the study of environmentally friendly and biocompatible modifier has become popular topics in the functional textile field.As a natural adhesive agent,dopamine has been of concern since its discovery.More and more textile related researches were focused on the multi-performance of dopamine in recent years.In this study,we investigated the application of dopamine used to obtain fabrics with functions such as structure color,antibacterial activity,hydrophobic property and conductive activity.We tried to form a polydopamine membrane in a static state on the surface of fabric using its self-polymerization property.The air contact conditions were different between the surface and the interior of dopamine solution in the process of self-polymerization,leading to a polymerization rate difference between two layers.Thus,the two-layer structure membrane with different particle size and film thickness is formed,which was suggested to be a special refraction-reflection structure.Diverse dopamine structural color films were formed after different reaction times.Through the dopamine structural color film experiment,five kinds of structural color films with bright colors and different absorption wavelengths of visible light were successfully obtained on the surface of the fabric after different reaction time.In this research,the ultraviolet light system was introduced,and the film formation time was shortened by 10 times compared to conventional conditions.The surface of dopamine structure color film was more flat and continuous formed under ultraviolet light condition.FE-SEM results showed that the total thickness,thickness of the upper layer and the diameter of the dopamine particles in the second layer of dopamine structural color films showed a similar extension trend with the increase of reaction time.What is more,XRD test verified that the unit cell of dopamine structural color membrane has a stable size and it does not change with different reaction times.By using the reduction and adhesion properties of dopamine,copper nanoparticles were obtained through in-situ reduction and adhered to the surface of the dopamine-modified fabric by a two-step impregnation process at room temperature without using other reducing agents.The modified fabric performed excellent and washable antibacterial,hydrophobic and antistatic properties.Through the dopamine in-situ reduction experiment,copper nanoparticles were proved to be reduced and adhered to the surface of the fabric by the results of XPS and FE-SEM.The obtained dopamine-modified fabric with copper nanoparticles adhered(C-Dopa-Cu)exhibited excellent superhydrophobicity,which was attributed to the strong adhesion between polydopamine and copper nano particles.After 30 standard washing circles,the water contact angle maintained above 150 °.The modified fabric C-Dopa-Cu also showed great antibacterial property with washing resistance.The antibacterial rate of E.coli achieved over 90% after 30 standard washing circles,which was significantly enhanced comparing to other copper antibacterial products.In order to achieve the conductive performance,sodium hypophosphite as strong reducing agent was used on the basis of the above modification.A large amount of copper nanoparticles was generated to form a uniform and continuous copper nano-film on the surface of dopamine modified fabric,covering the existing copper nanoparticles.The conductive experiment also confirmed that the presence of dopamine significantly increased the stability of the nano copper film.The modified fabric loaded with continuous nano copper film achieved a good conductive performance after 5 standard washing circles.