열에너지 수확용 멀티스케일 및 섬유강화 복합재의 열전 특성 평가

Abstract

n this research, two kinds of multifunctional materials that serve as not only structural but also thermoelectric materials were manufactured, and their applicability was assessed as thermoelectric materials. One is multiscale composite (carbon nanotubes(CNT)/glass fabric(GF)/epoxy) and the other is fiber-reinforced composite (carbon fiber(CF)/epoxy). GF/epoxy composites containing various contents of CNT were prepared by calendering with a threeroll-mill followed by a hand-layup process on a hot plate. Experiments confirmed that the electrical conductivity of multiscale composites increases as CNT concentration increases. In-plane thermal and electrical conductivities of multiscale and fiber-reinforced composites are higher than those in through-thickness direction due to the alignment effect of CNTs and continuity of woven fabric. In most cases, conductivities of fiber-reinforced composites are higher than those of multiscale composites. Calculating the Seebeck coefficients, we concluded that multiscale composites behave as n-type thermoelectric materials and fiber-reinforced composites showed p-type nature. Closed circuit consisting of two different types of materials showed appreciable electric currents in the presence of temperature gradients.