The Preparation And Electrical Properties Of Conductive Glass Fibers

Glass fibers have many excellent properties, such as high strength, high modulus, hightemperature resistance, chemical resistance, electrical insulation and so on, so it has been widelyused in many fields of the national economy. Reinforced polymeric matrix composites havebecome one of the most important applications of glass fibers, but the electrical insulation of resinmatrix and glass fibers, so the electronic equipments, which has a crust of glass fibers reinforcedresin matrix composites, may impact by external electromagnetic signal, not only affect thenormal operation of the equipments, but also may cause data leakage. If the glass fibers arewrapped with an highly conductive coating on surface, and then such composites are used aselectric fillers for the production of electromagnetic shielding materials. The composites, whichcombination of conductive glass fibers and resin is an important measure to solve the problem ofelectromagnetic wave pollution efficient. Electroless plating as the surface metallized technologyof materials, which is extensively used in many fields, has become one of the commonly usedtechnique for preparation conductive glass fibers, but in the procedure of conventional electrolessplating technology of glass fibers, the substrate needs roughened, sensitization, activationtreatment, not only the process is complex, and the activation treatment requires heavy metal ionsare expensive, while producing contamination by heavy metal ions, which are limited to thefurther development of preparation conductive glass fibers via electroless deposition method.Therefore, improvement new methods for preparation conductive glass fibers will be important.Bovine serum albumin (BSA) is an amphiphilic biological proteins, whose isoelectric point isbetween4.8-5.3. By adjusting the pH value of the BSA solution, so the protein can be adsorbed onorganic or inorganic substance surfaces. In this paper, using the amphiphilic performance of BSA,we do the following work: The graphene coated glass fiber composites were obtained from theelectrostatic adsorption of graphene oxide on bovine serum albumin (BSA) modified the glassfibers, and the reduction of graphene oxide coated glass fibers by hydroiodic acid in lowtemperature at40℃. The phase structure and functional groups of graphene oxide were studied byXRD and FT-IR, respectively. SEM images shown the morphology of glass fibers coated bygraphene: the graphene coating effect was improved with pH value decreasing, when the pH valueof graphene oxide dispersion was less than6. Zeta potential of graphene oxide and BSA moleculewere tested by Particle size/Zeta potential instrument, which showed that the isoelectric point of BSA was5.3, and the isoelectric point of graphene oxide was smaller than3. The conductivity ofgraphene wrapped glass fiber composites reached4.5S/m, and the conductive glass fibersmaintained original conductivity after different levels of bending. A LED light is lighted up bygraphene wrapped glass fibers materials insert a circuit. Under the heat treatment above120℃, theconductivity showed a little increase, due to the continued reduction of graphene. These resultsprove that the conductive glass fibers could be used at about200℃.In order to improve the electrical conductivity of the glass fiber, we attempt to prepareconductive glass fibers materials by silver particles-coated.Glass fibers with diameter of24-25μm were used in this work, which were manufactured inour laboratory. Glass fibers were immersed in Dopamine-HCl aqueous solution for24h with thepH value at8.5, and an adhesive sely-polymerized polydopamine coating was wrapped on surfaceof the glass fiber. The polydopamine film serves as a bridge between glass fibers and Ag particles.Electroless plating of Ag particles on the surface of glass fibers were obtained using potassiumsodium tartrate as a reducing agent, and the Ag conductive coating on glass fibers are studied bySEM, XPS and XRD. The results indicate that the Ag particles on surface of the glass fibers aresuccessive, compact and reduction thoroughly. The electrical conductivity of single fibers aredetected by electrochemical workstation, the conductivity reaches to2.4×106S/m and couldeasily light a LED lamp though conductive fibers insert in a circuit with different levels ofbending. The conductive glass fibers maintained original conductivity after different levels ofbending. Dopamine-HCl modified glass fibers ultrasound rinsing for3h,and then preparationsilver coated glass fibers materials, its conductivity also reaches to2.0×106S/m. Ultrasoundtreatment silver coated glass fibers for2h, silver particles layer don’t fall off, it indicates that theinterface between the particles layer and glass fibers have a good adhesion.These results indicate that, using bovine serum albumin and dopamine-HCl assurfaces modifiers for glass fibers, graphene and silver particles can coat on surface ofglass fibers effectively, and the conductive glass single fiber materials show excellentelectrical performance.