The Metallization And Performance Of The Carbon Fiber Surface

The carbon fiber has a broad application in civilian industry, biological materials,aerospace and other fields. Compositing carbon fiber and polymer materials is one ofthe principal means of production of the conductive material, while the resistance ofcarbon fiber itself is relatively high, and therefore it is an important research area ofmodification carbon fibers that how to use the metal coating method in order to improvethe conducticity of the carbon fibers. It can not only improve electrical conductivityproperties but also can remain the carbon fibers inherent advantages unchanged tometallizing the carbon fiber surface. This topic is depositing metal plating in the carbonfiber surface through the electroless plating process by using scanning electronmicroscope （SEM）, spectrum analysis （EDS）, conductivity meter, flame atomicabsorption spectrophotometer, dynamics calculation methods of characterization and themethods of studying the performance of the coating and plating solution.A pre-treatment on the carbon fibers. The result of studying the dispersing effect ofdifferent surfactants on the carbon fibers showed that the dispersion of the polyethyleneglycol in the carbon fiber is incomplete, part of the carbon fibers bonding together. Thedispersibility of dodecylbenzene sulfonic acid is relatively better than polyethyleneglycol. However dodecylbenzene sulfonic acid still does not make it completelydispersed, only part of the fiber two or three bonding together. Sodium dodecyl sulfatecan make carbon fibers dispersed completely, so its effect on the dispersion of thecarbon fiber is best. It made the conclusion that the best coarsening time was10min bydoing the carbon fiber coarsening experiment. The activation of the carbon fiber werestudied to determine that the effect of the colloid palladium activation10min was bestunder70℃and the surface of the carbon fibers contained catalytic palladium particles.Electroless copper plating on carbon fiber. Research different factors of affectingelectroless carbon fiber copper plating solution determined the optium conditions of theelectroless copper plating: Copper sulfate（CuSO₄·5H₂O）10g/L;Formaldehyde（37%HCHO）13mL/L; EDTA disodium（Na₂EDTA）15g/L; Sodiumpotassium tartrate20g/L; Sodium hydroxide（NaOH）12g/L; Thiourea0.2ml; Operating conditions:（pH=12.5; temperature:45℃; time:20min）. It studied the relationshipbetween the Cu²⁺ion concentration of the electroless plating solution and the time underthe different temperature, and analyzed and calculated the process of the electrolessplating which derived the activation energy of the electroless copper plating on carbonfiber Ea=32.68kJ/mol. It studied on the conductivity of the different quality of thecarbon fiber and coated carbon fibers dispersed in80ml distilled water; as a result, theconductivity of the drawn fiber is increased with the increasing amount. However, whenthe fiber added in an amount more than0.08g, the conductivity still increased but thefiber dispered in80ml distilled water will be incompletely dispersed. Thus it canconclude that the best added amount in80ml distilled water is0.08g and thecorresponding conductivity of the carbon fiber and copper coated carbon fiber valuesare12.5μs/cm and20.5μs/cm.Electroless nickel plating on carbon fiber. It researched each factor of influencingthe carbon fiber chemical plating in the chemical nickel plating solution, whichdetermines the best process condition of selectroless nickel plating: nickel sulfate（NiSO₄）30g/L; time and sodium phosphate （NaH₂PO₂）30g/L; lactic acid25mL/L;thiourea lead acetate trace; Operating conditions:（pH=4.5; temperature:70℃; time:20min）. It studied how the Ni2+ion concentration in carbon fiber chemical platingsolution changed with time under the different temperature. And it calculated thereaction activation energy of carbon fiber chemical plating nickel was Ea=11.12kJ/mol.The corresponding conductivity value of Nickel plated carbon fiber is18.5μs/cm, whilethe electrical conductivity increased obviously after carbon fiber chemical plating.Electroless copper plating nickel on carbon fiber. It used conductivity analyzer tomeasure electrical conductivity of copper and nickel plating on carbon fiber. It isconcluded that the electrical conductivity of carbon fiber composite coating is27.0μs/cm. Comparing the conductivity of copper plated carbon fiber, carbon fiber withnickel plated carbon fiber, we know that its conductivity increased significantlyand is akind of ideal conductive filler of electromagnetic shielding and absorbing materials.