The typical conductive polymer of PEDOT:PSS has recently attracted intensive attention in thermoelectric conversion because of its low cost and low thermal conductivity as well as high electrical conductivity. However, compared to inorganic counterparts, the relatively poor thermoelectric performance of PEDOT:PSS has greatly limited its development and high-tech applications. Here, we report a dramatic enhancement in the thermoelectric performance of PEDOT:PSS by constructing unique composite films with graphene quantum dots (GQDs). At room temperature, the electrical conductivity and Seebeck coefficient of PEDOT:PSS/GQDs reached to 7172 S/m and 14.6 μV/K, respectively, which are 30.99% and 113.2% higher than those of pristine PEDOT:PSS. As a result, the power factor of the optimized PEDOT:PSS/GQDs composite is 550% higher than that of pristine PEDOT:PSS. These significant improvements are attributed to the ordered alignment of PEDOT chains on the surface of GQDs, originated from the strong interfacial interaction between PEDOT:PSS and GQDs and the separation of PEDOT and PSS phases. This study evidently provides a promising route for PEDOT:PSS applied in high-efficiency thermoelectric conversion.

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Poly(amino acid)/nano hydroxyapatite (PAA/n-HA) bioactive composite was prepared by in situ melting polymerization. The composition, structure and morphology as well as glass transition temperature (T g ), dynamic mechanical properties of the PAA/n-HA composite were characterized by infrared spectrometer, X-ray diffractometer, X-ray photoelectron spectroscopy, scanning electron microscope, differential scanning calorimeter, and dynamic mechanical analyzer. The results indicated that the n-HA particles were uniformly distributed into PAA matrix and some interactions were found at the interface between PAA and n-HA, and the crystallinity of PAA in the composite decreased with the increase of n-HA content. The T g and storage modulus of the composite increased with increasing n-HA content, demonstrating that the n-HA content had obvious effects on the crystallization kinetic parameters and thermo properties of the PAA/n-HA composite. In addition, the n-HA amount had evident effects on the degradation of the PAA/n-HA composite in phosphate buffered saline (PBS), and the weight loss ratio of the composite decreased with the increase with n-HA content. The pH value of the medium was stable around 7.40 after the composite immersion into PBS for 8 weeks.

Polymers that possess highly nucleophilic pyrrolidinopyridine (Pyr) and primary amino (vinylamine, VAm) groups were prepared by free-radical copolymerization of N,N-diallylpyridin-4-amine (DAAP) and N-vinylformamide (NVF) followed by acidic hydrolysis of NVF into VAm. The resulting poly(DAAP-co-VAm-co-NVF) copolymers were water-soluble and reacted with water-dispersible polyurethane possessing a high content of unreacted isocyanate groups. Spray-coating of the nylon-cotton (NYCO), rayon, and poly(p-phenylene terephthalamide) (Kevlar 119) fibers pretreated with phosphoric acid resulted in covalent bonding of the polyurethane with the hydroxyl groups on the fiber surface. A second spray-coating of aqueous solutions of poly(DAAP-co-VAm-co-NVF) on the polyurethane-coated fiber enabled formation of urea linkages between unreacted isocyanate groups of the polyurethane layer and the amino groups of poly(DAAP-co-VAm-co-NVF). Fibers with poly(DAAP-co-VAm-co-NVF) attached were compared with fibers modified by adsorption of water-insoluble poly(butadiene-co-pyrrolidinopyridine) (polyBPP) in terms of the stability against polymer leaching in aqueous washing applications. While the fibers modified by attachment of poly(DAAP-co-VAm-co-NVF) exhibited negligible polymer leaching, over 65% of adsorbed polyBPP detached and leached from the fibers within 7 days. Rayon fibers modified by poly(DAAP-co-VAm-co-NVF) were tested for sorption of dimethyl methylphosphonate (DMMP) in the presence of moisture using dynamic vapor sorption technique. Capability of the fibers modified with poly(DAAP-co-VAm-co-NVF) to facilitate hydrolysis of the sorbed DMMP in the presence of moisture was uncovered. The self-decontaminating property of the modified fibers against chemical threats was tested using a CWA simulant diisopropylfluorophosphate (DFP) in aqueous media at pH 8.7. Fibers modified with poly(DAAP-co-VAm-co-NVF) facilitated hydrolysis of DFP with the half-lives up to an order of magnitude shorter than that of the unmodified fibers. The presented polymers and method of multilayer coating can lead to a development of self-decontaminating textiles and other materials.