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In order to mimic hierarchical nanostructures in nature, particles of polymer blends consisting of poly(4-butyltriphenylamine) (PBTPA), poly(methyl methacrylate) (PMMA) and PBTPA-block-PMMA were fabricated by a solvent evaporation method. Effects of the molecular weight and the chemical composition of PBTPA-b-PMMA, molecular weights of homopolymers, and the composition of the blend on the morphology were investigated. The polymer blend particle consisting of PBTPA and PMMA homopolymers exhibited thermodynamically favored core-shell structure, in which more hydrophilic PMMA-shell surrounded PBTPA-core. The addition of 10 wt% of PBTPA-b-PMMA caused the morphological transition from core-shell to Janus or inversed core-shell, in which PBTPA-shell surrounded PMMA-core, depending on the molecular weight of PBTPA segment in PBTPA-b-PMMA. When the molecular weight of PMMA segment was higher than that of PMMA homopolymer, watermelon-like particles in which small PBTPA domain less than 80 nm dispersed in the PMMA domain surrounded by PBTPA shell were observed. As the ratio of PBTPA-b-PMMA increased, the interface of the macrophase separation became obscure. At 50 wt% of the PBTPA-b-PMMA, only microphase separation was observed. The measurement of interfacial tension by pendant drop method demonstrated that PBTPA-b-PMMA lower the interfacial tension between PBTPA and the aqueous phase to the value similar to that of PMMA with the aqueous phase.

Here, we reported particles with approximately 80-μm diameter with phase-separated morphology of ternary polymer blends containing poly(4-butyltriphenylamine) (PBTPA), poly(methyl methacrylate) (PMMA), and PBTPA-b-PMMA fabricated via a microfluidic emulsification technique with a Y-shaped microreactor followed by a solvent evaporation. Addition of block copolymer changed the macroscopic structure from core-shell to Janus and more complicated sea-island type with the increase of the block copolymer content. The Janus structure with a PMMA hemisphere containing small PBTPA domain was observed at 10 wt% of the block copolymer. Meanwhile, the rapid evaporation changed the morphology macroscopically from the Janus to the undeveloped one where PMMA-rich phase mainly located at center sandwiched with outside PBTPA phases, suggesting that morphologies are governed by the kinetical factors together with the conventionally accepted thermodynamic ones. After the solvent annealing with toluene, distinct and enlarged PMMA phase appeared radiately, of which size gradiently decreased from the surface to the center (200–500 nm) in each particle.

Triphenylamine derivates have been utilized as building blocks in hole-transporting materials. Herein, we describe the synthesis of three octyl-derived conjugated triphenylamine macrocycles with different sizes, and a 4-(2-ethylhexyloxy)-substituted cyclic triphenylamine hexamer using a palladium-catalyzed C–N coupling reaction. These conjugated triphenylamine macrocycles not only have interesting structures, but also are capable of complexing with C60, C70 and PC61BM. Their binding stoichiometries with fullerenes were all determined to be 1 : 1 by an emission titration method. The association constants of these complexes were measured to be in the range of 0.115–1.53 × 105 M−1 depending on the cavity size of the triphenylamine macrocycles and the volume of the fullerenes. The space-charge-limited current properties of the complexes were further investigated using the fabricated ITO/PEDOT:PSS/active layer/Au devices.

Aerogels comprising poly(3-hexylthiophene) (P3HT) nanofibers dispersed in polystyrene (PS) were fabricated by freeze-drying, doped with iodine vapor, and subjected to thermoelectric property analys...

This study performs a novel examination of the gas transport properties in the poly­(lactic acid)/montmorillonite (PLA/MMT) interface layer by comparing the permeation parameters of dry gases and those dissolved in water. Furthermore, the relationship between the transport properties of oxygen and carbon dioxide in the gas and water phases and the crystallinity/crystal structure of the PLA/MMT composite films prepared by varying the MMT content in the PLA polymer and cooling conditions was systematically investigated. The results showed that the crystallinity of the PLA/MMT composite film increased with decreasing cooling rates, while the oxygen and carbon dioxide permeabilities increased with increasing MMT content and crystallinity. A small continuous space of size ranging from a few nanometers to a few dozen nanometers wherein the gas molecules easily diffuse around the interface might be formed between the crystalline and amorphous regions, which could not be observed by microscopic analysis. This interfacial space caused an increase in the selective permeation of carbon dioxide, which exhibits higher solubility in water, and the selective elimination of oxygen, which exhibits lower solubility in water.

The original synthetic strategy for a new type of poly(arylene vinylene) (PAV) is presented, where the C=C-bond-forming coupling of bis(alkoxycarbonyldiazomethyl)aromatic compounds is utilized as propagation. The strategy is unique in that the resulting PAVs have an alkoxycarbonyl group as an electron-withdrawing substituent on each vinylene carbon atom in the polymer main chain. Among the transition-metal catalysts examined in this study, RuCl(cod)Cp* (cod = 1,5-cyclooctadiene, Cp* = pentamethylcyclopentadienyl) is the most efficient, affording PAVs from a series of bis(alkoxycarbonyldiazomethyl)aromatic compounds with a high trans-C=C-forming selectivity of up to 90%. A PAV sample with a fluorenylene framework as an arylene moiety prepared by the Ru catalyst exhibited a hole mobility of 4 × 10–6 cm2 V–1 s–1.

We here report the facile fabrication of inverse core–shell and Janus structured particles consisting of poly(4-butyltriphenylamine) (PBTPA) and poly(methyl methacrylate) (PMMA) via a solvent evaporation from solution droplets of a polymer blend dispersed in an aqueous phase. Janus structured composite particles in which the PBTPA domain was partially coated by the PMMA domain were obtained using poly(vinyl alcohol) (PVA) as a suspension stabilizer. On the other hand, when sodium dodecyl sulfate (SDS) was added as a surfactant together with PVA, “inverse core–shell” particles in which the PMMA core was covered by the PBTPA shell were formed as well as Janus particles. TEM observation showed that the PMMA core was located at the center of the sphere and PBTPA layer has uniform thickness in inverse core–shell particles. The increase of the composition of PBTPA or the concentration of SDS increased the ratio of the inverse core–shell particles to the Janus ones.

Polymeric membrane-based gas separation has found wide applications in industry, such as carbon capture, hydrogen recovery, natural gas sweetening, as well as oxygen enrichment. Commercial gas separation membranes are required to have high gas permeability and selectivity, while being cost-effective to process. Mixed matrix membranes (MMMs) have a composite structure that consists of polymers and fillers, therefore featuring the advantages of both materials. Much effort has been made to improve the gas separation performance of MMMs as well as general membrane properties, such as mechanical strength and thermal stability. This perspective describes potential use of MMMs for carbon capture applications, explores their limitations in fabrication and methods to overcome them, and addresses their performance under industry gas conditions.

We applied a slide-ring (SR) gel to a Mg2+ ion gel electrolyte and clarified the electrical and mechanical properties in order to achieve a Mg2+ ion gel electrolyte with both sufficient mechanical strength and high ionic conductivity. The SR gel is made from polyrotaxane, which has a structure that consists of cyclic molecules, α-cyclodextrins (CDs), threaded by an axial polymer chain, polyethylene glycol (PEG), and cross-linked by divinyl sulfone. Pure glymes and tetraethylene glycol dimethyl ether (tetraglyme: G4) dissolving Mg2+ ions had no ability to swell the SR gel, whereas diethylene glycol dimethyl ether (diglyme: G2) and triethylene glycol dimethyl ether (triglyme: G3) dissolving Mg2+ ions were able to swell the SR gel. The swelling behavior was strongly dependent on the interaction between Mg2+ ions complexed with glymes and ether oxygens of a PEG-based hydroxypropyl PR (HyPR) network. Upon tensile elongation, SR gel swollen with G3 solution dissolving Mg2+ ions could be extended by 300%, which indicated the unique property of high ductility. The ionic conductivity of SR gel swollen with G3 dissolving Mg2+ ions, which approximately satisfied a Vogel-Tamman-Fulcher (VTF) dependence, was 1.73 mS cm−1 at room temperature, and the molar conductivity was 67% of that for a pristine G3 solution dissolving Mg2+ ions.

In this study, we synthesized and evaluated graft copolymers with polystyrene (PSt) as side chains on poly {[N,N´-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′ -bithiophene)} [P(NDI2OD-T2)], which is a typical n-type semiconducting polymer applied to in organic photovoltaics due to its intense optical absorption for the visible light, and high electron affinity. A well-controlled structure was confirmed by 1H-NMR analysis. It was found that enhanced electron mobilities in graft copolymer films were observed compared with the homopolymer. In order to clarify the role of PSt chains and the origins of the enhanced mobility, UV–vis absorption, electrochemical, morphological and thermal characteristics, and crystalline nature were investigated. As the results, it is suggested that the improved mobilities were attributed to the enhanced growth of π–π stacks, and increased crystallinity induced by PSt graft chains.

For the improvement of the electron transporting property of poly(9,9-di-n-octylfluorene) (PFO) as a conventional polymer light-emitting diode material, well-defined triblock copolymers of PFO [number-average molecular weight (M n) ≈ 10 000] with different chain length polystyrene (PSt) (M n ≈ 1000, 2000, and 3000) were synthesized via a combined synthesis strategy of Suzuki–Miyaura reaction, atom transfer radical polymerization, and Steglich coupling reaction. Electron-only devices for homopolymer and triblock copolymers were fabricated by a solution process. It was demonstrated that triblock copolymer (M n,PSt ≈ 2000) after annealing exhibited the highest electron mobility. Thermal, optical, electrochemical and morphological properties were investigated severally and revealed that the microphase separated structure was formed in block copolymers (M n,PSt ≈ 2000, and 3000) after annealing, and the introduction of PSt raised the glass transition temperature (T g) and deepened the lowest unoccupied molecular orbital level.

The critical phenomena of double percolation on polybutadiene (PB)/polyethylene glycol (PEG) blends loaded with poly-3-hexylthiophene (P3HT) nanofibers is investigated. P3HT nanofibers are selectively localized in the PB phase of the PB/PEG blend, as observed by scanning force microscopy (SFM). Moreover, double percolation is observed, i.e., the percolation of the PB phase in PB/PEG blends and that of the P3HT nanofibers in the PB phase. The percolation threshold (&phi, cI) and critical exponent (tI) of the percolation of the PB phase in PB/PEG blends are estimated to be 0.57 and 1.3, respectively, indicating that the percolation exhibits two-dimensional properties. For the percolation of P3HT nanofibers in the PB phase, the percolation threshold (&phi, cII) and critical exponent (tII) are estimated to be 0.02 and 1.7, respectively. In this case, the percolation exhibits properties in between two and three dimensions. In addition, we investigated the dimensionality with respect to the carrier transport in the P3HT nanofiber network. From the temperature dependence of the field-effect mobility estimated by field-effect transistor (FET) measurements, the carrier transport was explained by a three-dimensional variable range hopping (VRH) model.

The global energy market is in a transition towards low carbon fuel systems to ensure the sustainable development of our society and economy. This can be achieved by converting the surplus renewable energy into hydrogen gas. The injection of hydrogen (⩽10% v/v) in the existing natural gas pipelines is demonstrated to have negligible effects on the pipelines and is a promising solution for hydrogen transportation and storage if the end-user purification technologies for hydrogen recovery from hydrogen enriched natural gas (HENG) are in place. In this review, promising membrane technologies for hydrogen separation is revisited and presented. Dense metallic membranes are highlighted with the ability of producing 99.9999999% (v/v) purity hydrogen product. However, high operating temperature (⩾300 °C) incurs high energy penalty, thus, limits its application to hydrogen purification in the power to hydrogen roadmap. Polymeric membranes are a promising candidate for hydrogen separation with its commercial readiness. However, further investigation in the enhancement of H2/CH4 selectivity is crucial to improve the separation performance. The potential impacts of impurities in HENG on membrane performance are also discussed. The research and development outlook are presented, highlighting the essence of upscaling the membrane separation processes and the integration of membrane technology with pressure swing adsorption technology.

We reported that supercritical (sc) annealing of poly(3-hexylthiophene) (P3HT), and its block copolymers with poly(ethylene oxide) (PEO) and polystyrene (PSt) brought about improvements in the crystal structure and hole mobility, determined by the space charge limited current (SCLC) measurement. P3HT-b-PEO showed the largest increase in mobility. From the XRD profile, it was found that the treatment with scCO2 increased the crystallite size and crystallinity. UV–vis spectra showed that the effective conjugation length in the scCO2 treated films was increased, compared to the as-spun samples, suggesting that CO2 molecules are incorporated into domains of the second block domains and P3HT amorphous region, and assist to alter the characteristics of the crystalline region. Then, it was considered that the change in the crystalline structure and the improvement of P3HT chains packing led to enhanced mobility. Since PEO is known to have a higher affinity for CO2, the increase of mobility was specifically intensive.

Supercritical carbon dioxide (sc-CO2) will plasticize and partially solubilise polymeric membranes, resulting in alteration to the polymer morphology, impacting the gas separation properties. Here, cellulose triacetate (CTA) and polyimides, Matrimid and 6FDA-TMPDA membranes were exposed to supercritical CO2 for 2 and 8 h, followed by two depressurization protocols; a rapid depressurization of 12 MPa/min and a slow depressurization of 0.17 MPa/min. The resulting impact on He, N2, CH4 and CO2 permeability as well as the corresponding selectivities were then quantified. Matrimid membranes undergo substantial plasticization in the presence of sc-CO2 resulting in significant increases in permeability and loss of selectivity, irrespective of the sc-CO2 exposure protocol. CTA and 6FDA-TMPDA membranes experience competing phenomenon under supercritical conditions, both demonstrate limited CO2 plasticization which is offset by sc-CO2 partly solubilising the polymers, enabling rearrangement to a more compact morphology. The depressurization protocol strongly impacted the underlying morphology for these two membranes. Rapid depressurization resulted in a higher fractional free volume and greater gas permeability, which is attributed to the sudden expansion of CO2 sorbed in the polymer opening up the morphology. Slower depressurization resulted in a lower fractional free volume and decreased gas permeabilities, because the CO2 gradually desorbs, leaving behind a more dense morphology. The resulting decrease in permeability also corresponded with a significant increase in selectivity. For both CTA and 6FDA-TMPDA membranes the sc-CO2 treatment improved the gas permselectivity relative to the original state. Therefore, exposure to sc-CO2 presents an advantageous process to improve the performance of common polymeric membranes for gas separation.

Here, we report the morphological transition of a phase-separated structure from core–shell to Janus morphology in droplets consisting of a poly(4-butyltriphenylamine) (PBTPA)/poly(methyl methacrylate) (PMMA) blend solution, induced by UV light irradiation. We obtained a phase-separated structure formed by the evaporation of the solvent from polymer solution droplets dispersed in an aqueous solution containing a surfactant. The rate of transition decreased with increasing polymer concentration and diameter of the droplet. It was also found that the transition was caused by UV light with a wavelength of 365 nm, which is mainly absorbed by PBTPA, indicating that this phenomenon is triggered by PBTPA. When the droplet was heated to 75 °C, no transition was observed.

The presence of condensable aromatic hydrocarbons in raw natural gas streams creates a significant challenge for acid gas removal through membrane separation. In this work, the impact of toluene and xylene on the gas separation performance of cellulose triacetate (CTA) membranes was studied. When operating at low CO2 partial pressures (0.75 bar), both toluene and xylene reduced the permeation of CO2 at low vapour activities, due to competitive sorption and the pore-filling or anti-plasticisation effect. Conversely, at vapour activities greater than 0.5, toluene caused membrane plasticisation, possibly coupled with a decrease in crystallinity. On the other hand, when operating at 7.5 bar CO2 pressure, plasticisation was observed at a lower vapour activity of 0.3 for both toluene and xylene. This study shows that two penetrants can influence the plasticisation behaviour in a co-operative manner that cannot be described by a simple additive model. The study also shows that the permeabilities of toluene and xylene are comparable with that of methane.

A series of mixed matrix membranes using a commercially available aromatic polyimide (Matrimid® 5218) with nanoparticles formed from carbon, a porous organic polymer and metal organic frameworks were prepared to investigate the effects of flue gas impurities on gas permeation. We show that common impurities found in power station flue gases (H2S, SO2, and NO) have significant effects upon the performance of these mixed matrix membranes. The effects of NO, SO2 and H2S on the zeolitic imidazolate framework ZIF-8 are all large and rapid and would render these membranes unsuitable for flue gas service that do not use flue gas desulfurisation. Similarly, H2S adsorbs irreversibly into membranes containing copper benzene-1,3,5-tricarboxylate (Cu-BTC), although the impacts of NO and SO2 are less severe. The membranes containing a porous organic polymer or porous carbon are less affected by these contaminants. In particular, the permeability of the membrane containing the porous organic polymer is still significantly above that of the base Matrimid polymer after exposure for 80 days to 1000 ppm of each contaminant. Further, this mixed matrix structure shows enhanced H2S selectivity. These results suggest that MMMs prepared using organic based nanoparticles can be effective in gas separation applications such as natural gas sweetening, biogas purification and post-combustion carbon capture, when acid gases are present as an impurity.

A novel cyclic emitter composed of tetraphenylsilane and tetraphenylethene backbone was successfully synthesized through a convenient homocoupling procedure. The optical and thermal properties of t...

In natural gas sweetening, gas dehydration with glycols is typically carried out upstream of membrane separation of carbon dioxide. This means that when process upsets occur, these glycols can reach the membrane unit. In this work, we study the impact of two common glycols (monoethylene glycol and triethylene glycol) on the gas transport performance of cellulose triacetate membranes. We find that the glycol absorbed into the membrane initially obstructs the permeation of CH 4 and CO 2, due to pore filling or antiplasticisation effects, but the permeability then increases again, indicative of polymer relaxation and a loss of crystallinity in the polymer. The smaller helium molecule is significantly less affected by the presence of the glycols, possibly because its lower solubility within glycol limits its movement through the swollen structure. However, after removing the glycols with a methanol wash, the membrane performance recovers with only a slight residual plasticisation observed. In addition, the permeation of H 2 S, a common contaminant within natural gas streams, was studied across a range of temperatures. At the partial pressures studied (up to 0.75 kPa), H 2 S had very little effect on the membrane performance even in long-term exposure for up to 300 days.

A new macrocyclic AIE emitter composed of triarylamine backbone was successfully synthesized through convenient homocoupling procedure and easily purified by silica gel column chromatography, and recrystallization. The optical and electrochemical properties of the compound have been investigated. Intriguingly, the compound shows dual emission both 423 nm and 505 nm. This result implied that the violet emission was originated from an isolated component of the emitter, whereas the yellowish-green emission simultaneously exhibited AIE nature. The compound exhibits enough thermal stability and high glass transition temperature to be applied for organic devices.

Mixed matrix membranes (MMMs) for carbon dioxide (CO2) separation composed of a commercial aromatic polyimide as a host matrix and carbon nanoparticles as a filler phase have been prepared by a casting method. The solubility of CO2 in the MMM could be predicted within error from the pure component isotherms, suggesting that the sorption of polymer to the nanoparticles did not significantly reduce the availability of sites for CO2 to adsorb. The CO2 permeability increased with filler loading without a reduction in the gas selectivity, reflecting the increase in fractional free volume provided by the carbon nanoparticles. This was reflected in significant changes in the CO2 diffusivity. However, contrary to prior work, the use of the carbon nanoparticles was unable to reduce the effects of plasticisation by either CO2 or water. Changes in the permeability of both water vapor and carbon dioxide occurred with time, particularly for relative humidities beyond 60%. The lack of plasticization resistance may reflect the use of sub-micron nanoparticles rather than larger ones.

Three types of block copolymers consisting of polyfluorene and polytriarylamine with benzothiadiazole (BT) moiety are synthesized and characterized to evaluate the effect of chromophore location on electroluminescent performance. BT unit is incorporated at the junction of both blocks (BP 1) in the polytriarylamine block (BP 2) and in the polyfluorene block (BP 3). Electroluminescent device based on BP 1 exhibits the best performance. This result is reasonably explained by taking into consideration the difference of recombination probability in the phase-separated active layers.

We propose using a slide-ring (SR) gel electrolyte to achieve a gel polymer electrolyte with both sufficient mechanical strength and high ionic conductivity. The SR gel is made from polyrotaxane, which has a structure that consists of cyclic molecules, α-cyclodextrins (CDs), threaded by an axial polymer chain, polyethylene glycol (PEG), and cross-linked by divinyl sulfone. The SR gel electrolyte was made from SR gels which were swollen by an electrolyte solution (ES) prepared with lithium salt and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI). The swelling behavior of SR gel in the ES by the formation of coordination bonds between lithium cations and oxygen atoms on CDs was investigated. The swelling behavior and ionic conductivity of the SR gel swollen with ES had a peak at 0.8 M lithium ion in the ES and the molar conductivity of the SR gel swollen with ES was 85% more than that of pristine ES. The puncture resistance of the SR gel electrolyte was also investigated; the puncture elongation was more than 1000% and the Young’s modulus increased with the lithium ion concentration due to an increase in the coordination bonds between lithium cations and the oxygen atoms on CDs.

The permeabilities of gaseous and dissolved (in water) oxygen and carbon dioxide through a Kurome natural lacquer film, as well as the water vapor permeability, were systematically investigated. The Kurome lacquer films contained water in their oil emulsion structure, and the films had phase-separated structures with hydrophobic glassy (i.e., urushiol) and hydrophilic rubbery (i.e., polysaccharide) polymer components. The Kurome lacquer films exhibited a relatively higher permeability for water vapor than for oxygen and carbon dioxide, indicating that the presence of hydrophilic components influenced the water vapor permeability. The gas permeation behavior of the Kurome lacquer films revealed that they behave like glassy and rubbery polymers in the dry and wet states, respectively. Thus, Kurome lacquer films are polymer materials that adapt to different environments in the presence of moisture.

We fabricated complementary devices with a pn junction between p-type nanofiber /PMMA composite film and n-type nanofiber /PMMA composite film and evaluated the temperature dependence. This full-organic pn junction, fabricated in this study showed rectification, but, as the temperature decreased, the current in forward direction became smaller and the ideal coefficient tended to increase. In addition, the energy gap obtained from the temperature dependence of the reverse saturation current of the fabricated pn junction was influenced by the leakage current in the negative voltage region and the impurity of the dopant to compensate for n-type carrier deficiency, which was very small. Even in the case of using a flexible substrate, this pn junction showed rectifying properties. However, this rectification was lost by bending.