ABSTRACT
Controlling the polymerization of aniline in the presence of zirconium-based metal-organic frameworks (Zr-MOFs) using polystyrene sulfonic acid as a dopant resulted in the formation of a new type of free-standing thermoelectric composite film. Polyaniline chains interpenetrate into the Zr-MOFs to enhance the crystallinity of polyaniline, resulting in an improved degree of electrical conductivity. In addition, the inherent porosity of the Zr-MOFs functions to suppress the increase in thermal conductivity, thus dramatically promoting a negative Seebeck coefficient. When 20 wt % Zr-MOF was used, a power factor of up to 664 µW/(m K2) was obtained, which was accompanied by a surprisingly large, negative Seebeck coefficient. The new class of MOF-based composites offers a new direction for developing new types of efficient thermoelectric materials.
ABSTRACT
p-Phenediamino-modified graphene (PDG) has been newly synthesized via a facile green one-step chemical route as a functionalized graphene-based additive to copolymerize with aniline for fabricating innovative PDG/polyaniline conducting polymer composites containing very special semi-interpenetrating networks (S-IPNs). The S-IPNs not only provide additional pathways by creating chemically bonded PDG and PANI for smoothly transporting carriers but greatly reduce the amount of graphene required to less than a few percent could effectively improve the overall electrical conductivity, Seebeck coefficient, and thus the thermoelectric (TE) performance. The found optimized TE figure of merit (ZT) of 0.74 approaches a practical high level which is comparable or much higher than previously reported ones for TE polymers.
