نوع مقاله : پژوهشی
نویسندگان
تهران، پژوهشگاه پلیمر و پتروشیمی ایران، پژوهشکده فرایند، گروه لاستیک، صندوق پستی 112-14975
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Hypothesis: PAN-based carbon fibers exhibit inherently low interfacial adhesion to epoxy matrices due to their chemically inert surfaces. It is therefore expected that anodic oxidation in two different electrolytes (acidic and alkaline) will enhance interfacial bonding by introducing active functional groups and increasing surface roughness. It is further hypothesized that the electrolyte type and the applied potential conditions will significantly influence the extent of chemical modification and, consequently, the interlaminar shear strength (ILSS) of the resulting composites.
Methods: Surface modification was carried out using HNO₃- and NaOH-based electrolytes at fixed concentrations under ambient temperature. Anodic oxidation was performed using a three-electrode electrochemical system equipped with a potentiostat, consisting of a carbon-fiber working electrode, a platinum counter electrode, and an Ag/AgCl reference electrode. The fibers were oxidized via two approaches: (i) cyclic voltammetry (six cycles) to identify the effective oxidation potential, and (ii) potentiostatic oxidation at a constant potential for 3 and 10 minutes.
Findings: Cyclic voltammetry revealed the potential range at which surface oxidation initiates, enabling the selection of an appropriate fixed potential for the main oxidation step. Attenuated total reflectance- Fourier transform infrared spectroscopy (ATR-FTIR) analysis confirmed the formation of oxygen-containing (e.g., C=O) and nitrogen-containing functional groups depending on the electrolyte used. Energy Dispersive X-ray spectroscopy (EDS) analysis showed a substantial increase in surface oxygen and nitrogen content after oxidation. SEM images revealed significant changes in fiber surface morphology—specifically, increased roughness due to layer-by-layer etching—and improved fiber–matrix interfacial adhesion in the composite fracture surfaces. The enhanced ILSS values following anodic oxidation corroborate the synergistic contributions of chemical functionalization and mechanical interlocking to stronger interfacial bonding.
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کلیدواژهها [English]
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