A structurally interconnected block copolymer was facilely prepared by the oligomerization of poly(oxyethylene)-segmented diamine and 4,4 0 -oxydiphthalic anhydride, followed by a late-stage curing to generate amide-imide cross-linked gels. The gel structure, with multiple functionalities including poly(oxyethylene) segments, amido-acid linkers, amine termini, and amide cross-linker was characterized by Fourier transform infrared spectroscopy. The gel-like copolymer was used to absorb a liquid electrolyte; formation of 3D interconnected nanochannels, as could be observed by field emission scanning electronic microscopy has confirmed this absorption of the liquid electrolyte by the copolymer.This elastomeric copolymer was used as the matrix of a polymer gel electrolyte (PGE) for a dyesensitized solar cell (DSSC), which shows extremely high photovoltaic performance (soaking for 1 h in the electrolyte). In particular, the PGE containing 76.8 wt% of the liquid electrolyte renders a power conversion efficiency of 9.48% for its DSSC, with a short-circuit photocurrent density of 19.50 mA cm À2 , an open-circuit voltage of 0.76 V, and a fill factor of 0.64. The outstanding performance of the gel-state DSSC, superior to that (8.84%) of the DSSC with the liquid electrolyte, is mainly ascribed to the suppression of the back electron transfer through the PGE. Electrochemical impedance spectra, and dark current measurements were used to substantiate the explanations of the photovoltaic parameters.

A cross-linked copolymer was previously synthesized from poly(oxyethylene) diamine (POE-amine) and an aromatic anhydride and cured to generate an amide-imide cross-linking structure. The copolymer containing several chemical groups such as POE, amido acids, and imide, enabled to absorb liquid electrolytes in methoxypropionitrile (MPN) for suitable uses in dye-sensitized solar cells. To establish the advantages of polymer gel electrolytes (PGE), the same copolymer was studied by using different electrolyte solvents including propylene carbonate (PC), dimethylformamide, and N-methyl-2-pyrrolidone, and shown their long-term stability. The morphology of the copolymer after absorbing liquid electrolytes in these solvents was proven the same as a 3D interconnected nanochannels, evidenced field emission-scanning electron microscopy. Among these solvents, PC was selected as the optimized PGE, which demostrated a higher power conversion efficiency (8.31%) than that of the liquid electrolyte (7.89%). In particular, the long-term stability of only a 5% decrease in the cell efficiency after 1000 h of testing was achieved. It was proven the developed copolymer as PGE was versatile for different solvents showing high efficiency and long-term durability.

A dispersion of platinum-on-graphene was prepared essentially by a two-step process, involving uniform distribution of graphene nanoplatelets in a cosolvent of ethanol-water in the presence of a polymeric dispersant and subsequent in situ reduction of dihydrogen hexachloroplatinate to metallic platinum on the graphene surface. The process generated platinum nanoparticles (PtNPs) of ca. 4.0-10 nm in diameter on the graphene surface. The platinum-on-graphene dispersion was coated on an FTO glass to prepare a counter electrode (CE) for a dye-sensitized solar cell (DSSC). The hybrid film of platinum nanoparticles and graphene nanoplatelets (PtNP/GN) showed a transparency of 70% at 550 nm, indicating its suitability as a CE material for a rear-illuminated DSSC. The DSSC with the CE having the film of PtNP/GN exhibited a power conversion efficiency (h) of 8.00%, superior to 7.14% of the DSSC with a conventional sputtered platinum (s-Pt) CE. In the case of rear-illumination the DSSC showed an h of 7.01%, while the DSSC with the conventional s-Pt showed an h of only 2.36%. HRTEM and FE-SEM were used to observe the dispersion of the hybrid material in the solvent, UV-vis spectroscopy and cyclic voltammetry were used to characterize the films, and IPCE spectra and electrochemical impedance spectra were used to explain the photovoltaic parameters of the DSSCs.

This study investigated films with remarkably high electrical conductivity after they were easily prepared from organic/inorganic nanohybrid solutions containing an organic polymeric dispersant and two-dimensional nanoscale silicate platelets as the inorganic stabilizer dispersed with silver nanoparticles. Transmission electron microscopy shows that the production of silver nanoparticles synthesized by the in situ chemical reduction of AgNO3 in an aqueous solution by N,N-dimethylformamide results in an average silver nanoparticle diameter of circa 20 nm. Thin films of silver nanoparticles were prepared on a 1-μm-thick film with a low sheet resistance of 8.24 × 10−4 Ω/sq, achieved through the surface migration of silver nanoparticles and prepared by sintering at 300 °C to form an interconnected network. This was achieved with a silver nanoparticle content of 5 wt%, using nanoscale silicate platelets/polyoxyethylene-segmented polyimide/AgNO3 at a weight ratio of 1:10:35. During sintering, the color of the hybrid film changed from gold to milky white, suggesting the migration of silver nanoparticles and the formation of an interconnected network. The results show promise for the fabrication of novel silver-based electrocardiogram electrodes and a flexible wireless electrocardiogram measurement system for wearable electronics.

We report a family of novel dispersants that are highly effective for finely dispersing carbon nanotubes (CNT) and silver nanoparticles (AgNPs) in aqueous medium. The imide functionalized dispersants were prepared from the amidation of diamine and dianhydrides such as 4,4 0 -oxydiphthalic dianhydride, 4,4 0 -carbonyldiphthalic anhydride and pyromellitic dianhydride. The poly(oxyalkylene)-diamines with different backbones including poly(oxypropylene) (POP) and poly(oxyethylene) (POE) were allowed to react with dianhydride at 2 : 1 to 7 : 6 molar ratio under the conditions of condensation at 150 C. The amidoacid intermediates were readily converted into cyclic imide structures as the thermodynamic products, as characterized by Fourier transform infrared. These copolymers were screened for the dispersed ability for CNT in a DMF-H 2 O mixture, characterized by UV-visible absorption. The comparison identified that the amine-terminated and POE-segmented imide (POE-imide) at >6 : 5 of amine/ anhydride ratio was more effective for dispersing CNT than the anhydride-terminated imide analogs and POP-segmented imide. The tandem procedures of dispersing CNT and then AgNPs were developed by in situ reduction of AgNO 3 in the presence of the POE-imide dispersant. As a result, the homogeneous dispersion of mixtures of CNT-tethered AgNPs (20-30 nm in diameter) and free AgNPs (8-30 nm) was prepared. Furthermore, the AgNPs/CNT nanohybrid was also isolated by centrifugation and removal of the free AgNPs, and characterized by transmission electron microscopy and we prepared a conductive film (10 mm) with the conductivity of 10 3 to 10 5 S cm À1 by controlling the annealing temperature in air.