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In this work, a new series of supramolecular discotic liquid crystals induced by hydrogen bonding between triazines T x and aromatic acids A y are presented, most of which exhibit columnar mesomorphic properties. The design strategy of combining the hydrogen bond parallel to the molecular plane with the π-stacking trend of triazine derivatives and aromatic acids was utilized, which has been widely confirmed by nematic, smectic or columnar liquid crystal phases. The formation of hydrogen bonded complexes was proven by FT-IR and 1H NMR spectroscopy and their stability studied by variable temperature FT-IR techniques. All prepared hydrogen bonded complexes displayed mesogenic properties and their liquid crystalline properties were investigated by means of DSC, POM and XRD. This work provides useful information to assist our further design of hydrogen bonded supramolecular liquid crystals for optoelectronic applications.

A sustainable and low-cost separator is highly required for electrochemical energy storage systems. Herein, a type of modified natural wood film with excellent mechanical properties, ion conductivity and thermal stability is fabricated for high-performance lithium ion batteries. Using the modified natural wood film as a separator, the fabricated symmetric cell exhibits a more stable and lower plating/stripping voltage for Li than that of the cell with a commercialized polypropylene (PP) separator. The LiFePO

Mechanically compressible energy devices represent one of the most promising candidates for powering flexible and portable electronics, but often suffer from their limited stability of performance under high compressive strains....

The 3D supramolecular framework (3D-SF) is constructed in this work through the hydrogen bond assisted self-assembly of spherical dendritic nanopolymer to regulate the flexibility, stability, and resistive switching (RS) performance of perovskite resistive random-access memory (RRAM). Herein, the 3D-SF network acts as the perovskite crystallization template to regulate the perovskite crystallization process due to its coordination interaction of functional groups with the perovskite grains, presenting the uniform, pinhole-free, and compact perovskite morphology for stable flexible RRAM. The 3D-SF network in situ stays at the perovskite intergranular boundaries to crosslink the perovskite grains. The RS performance of 3D-SF-modified perovskite RRAM device is evidently improved to the ON/OFF ratio of 10

Both perovskites and organic semiconductors are promising candidates for next-generation portable and wearable photodetectors (PDs), owing to their facile solution processibility and remarkable optoelectronic features. In recent years, there has been growing interest in combining the two and constructing perovskite/organic hybrid PDs, which are demonstrated to present a broad photoresponse spectrum, high photoresponsivity and good environmental stability. Since great progress has already been made, a comprehensive summary would be very important for this field. However, this is still lacking. In this review, we provide a thorough progress report and in-depth discussion on the perovskite/organic hybrid PDs, from the very fundamental device operation principles to advanced design strategies. Firstly, the main parameters of the PD devices are introduced. Then, the developments of the perovskite/organic hybrid PDs, including photodiodes, photoconductors and phototransistors, are discussed in detail. Finally, current challenges are summarized and potential solutions are proposed.

Random resistive access memory (RRAM) devices with a simple structure, low power consumption, and tunable switching behavior have emerged as promising candidates to simulate biological synapses. Here, we demonstrate solution-processable RRAM devices with FeC–rGO nanocomposites by intercalating nano-aggregating ferrocenes (FeCs) between the reduced graphene oxide (rGO) sheets, in which FeCs anchor on the surface of rGO through π–π stacking interactions. The Al/FeC–rGO/ITO devices fabricated by spin-coating exhibit a low SET/RESET voltage of −1.7 V/+2.1 V and a high ON/OFF ratio of 108, which results from the formation/rupture of conductive paths between rGO sheets gated by the redox of FeCs. Besides, the devices show high repeatability, excellent durability and favorable flexibility. In addition, the obtained device can be utilized to simulate the potentiation and depression of synapses by applying a pulse voltage below VSET, further contributing to image pattern recognition. Thus, this approach aims to fabricate information storage devices for future use in artificial intelligence.

Flexible supercapacitors have attracted increasing interest due to their high power density, long-term cycling life and excellent safety. Like other energy storage devices, flexible supercapacitors exhibit serious performance degradation as they work in extremely cold and/or sweltering climates, which greatly limit their practical applications. Here, we demonstrate a polymer hydrogel with high ionic conductivity for flexible supercapacitors with high performance and excellent climate tolerance. The wide temperature adaptability of the polymer hydrogel is enabled by introducing an additive of dimethyl sulfoxide, which can form abundant hydrogen bonds with water molecules and functional groups of polymer molecules. The optimized hydrogel exhibits high ionic conductivities of 0.82 and 1.12 S m−1 at −20 and 100 °C, respectively, comparable with that at room temperature. Using the polymer hydrogel as an electrolyte, the resulting supercapacitors not only show high electrochemical performance, but also exhibit high capacitance retention up to 91% and 85% at both low (−20 °C) and high (100 °C) temperatures, compared with that at room temperature. In addition, the developed supercapacitors possess excellent mechanical flexibility even at −20 °C. Polymer hydrogels with wide temperature tolerance could be easily functionalized and broadly used for other flexible energy devices and electronics working in harsh environments in the future.

Dental plaque biofilms are believed to be one of the principal virulence factors in periodontitis resulting in tooth loss. Traditional mouthwashes are limited due to the continuous flow of saliva and poor drug penetration ability in the biofilm. Herein, we fabricated an antibiotic delivery platform based on natural polysaccharides (chitosan and cyclodextrin) as a novel mouthwash for the topical cavity delivery of minocycline. The penetration and residence mechanisms demonstrate that the platform can prolong the residence time up to 12 h on biofilms. Furthermore, sustained release can enhance the penetration of drugs into biofilms. In vitro antibiofilm experimental results indicated that the mouthwash effectively kills bacteria and eradicate biofilms. Effective treatment in vivo was confirmed by the significantly reduced dental plaque and alleviated inflammation observed in a rat periodontitis model. In summary, this novel platform can improve antibiofilm efficiency and prevent drugs from being washed away by saliva, which may provide benefits for many oral infectious diseases.

A series of novel hyper-structured molecular (HSM) thermally activated delayed fluorescent (TADF) emitters, in which the TADF units and host units are bound together into one inactive core through flexible linkages, were designed. Phenoxazine-triphenyltriazine (PXZ-Trz), 1,3-bis(9H-carbazol-9-yl)benzene (mCP) and calix[4]resorcinarene (CRA) were chosen as the TADF unit, the host unit and the core, respectively. A series of CRA-based HSM emitters, CRA-PXZ-Trz(X)-mCP(100−X) (X = 0, 12.5, 25, 50, 75, 87.5 or 100) were successfully synthesized by a two-step click reaction. Upon using non-doped CRA-PXZ-Trz(87.5)-mCP(12.5) as the light-emitting layer, the solution-processable OLEDs emitted yellow-green light, and displayed an external quantum efficiency of 16.7% at 100 cd m−2.

The fiber-shaped resistive random access memory (RRAM) is an important subject for flexible wearable electronic textiles. The investigation of the resistive switching (RS) performance of the materials in the basic storage unit (crosspoint) of a flexible fibrous crossbar is very significant for realizing flexible wearable memories. In this work, fibrous crosspoint RRAM devices, abbreviated as FCPe-RRAMs, have been fabricated on the basis of organic–inorganic halide perovskite MAPbI3. Herein, a functional Al@MAPbI3 fiber is first prepared via a simple dip-coating method, in which the low-temperature solution processing method and cheap raw materials are conducive to the future large-scale and low-cost production. By optimizing the preparation conditions for MAPbI3, a pinhole-free, compact and uniform perovskite film is deposited on the bare Al fiber. Then, the FCPe-RRAM devices with a configuration of Al@MAPbI3/Al are assembled on a homemade holder by perpendicularly crossing the bare Al fiber and the functional Al@MAPbI3 fiber at a certain bending angle. The FCPe-RRAM devices exhibit a bipolar RS behaviour. The highest ON/OFF ratio reaches up to approximately 106 in the FCPe-RRAM devices, together with a low SET/RESET voltage (+1.66 V/−0.47 V) and a long retention time (>104 s). The FCPe-RRAM devices also exhibit excellent reproducibility and operational uniformity, which are important for practical applications in mass production. The investigation of the RS mechanism suggested that the FCPe-RRAM devices follow the mechanism of conductive metallic filament formation by the generated electrons with the help of thermionic emission. This work reveals the potential promising applications of FCPe-RRAM devices in flexible wearable memories with high storage density.

The innovation of photoactive layer materials is crucial for improving the power conversion efficiency (PCE) of polymer solar cells (PSCs). Herein, we report two polymer donors (PBTN-o and PBTN-p), which only differ in alkyl chains substituted at sites (6,7- or 5,8-) of the naphtho[2,3-c]thiophene-4,9-dione (NTD) unit. The single crystals of both NTD monomers demonstrate that NTD with alkyl chains at the 6,7-sites has a planar NTD skeleton, and surprisingly, NTD with alkyl chains at the 5,8-sites produces a bent NTD skeleton. The bent NTD-based polymer (PBTN-p) exhibits a more twisted conjugated backbone than PBTN-o. Our comparative studies show that PBTN-p possesses suitable aggregation properties that can optimize the photoactive layer morphology in NF PSCs. In PSCs, the optimal PBTN-o:BO-4Cl-based device shows a PCE of 11.85% with a VOC of 0.84 V, JSC of 22.41 mA cm−2, and FF of 0.63. In contrast, the optimal PBTN-p:BO-4Cl-based device exhibits a better PCE of 14.10% with the same VOC of 0.84 V, and an enhanced JSC of 24.67 mA cm−2 and FF of 0.68. This work provides a new insight into BHJ morphology optimization by side chain induced polymer main chain twisting in PSCs.

We report uniform mesoporous LiNi0.5Mn1.5O4 microcubes grown from nanowires via oriented attachment. Mechanical tests show that the microcubes had excellent elongation performances. Electrochemical measurements show that LiNi0.5Mn1.5O4 microcubes delivered an initial discharge capacity of 123 mAh g−1 at 1C and maintained 95% of the capacity after 50 cycles.

We report a facile, rapid, phase-transfer-assisted process to prepare Ag nanoparticles (AgNP) loaded graphene oxide (GO) nanocomposite, by using cysteine as a highly-effective phase transfer agent for AgNP movement from organic phase to water and subsequently as a covalent linkage for immobilizing AgNP on GO. The obtained c-Ag/GO nanocomposite possesses high nanoparticle loading efficiency, small particle size and monodispersity, strong binding force and good water dispersibility, which endow it with great potential in a variety of bio-applications. To illustrate potentail application, c-Ag/GO and its derivatives c-Ag/rGO were used for antibiosis and biosensing, respectively. The c-Ag/GO composite demonstrates high antibacterial activity against E. coli with a minimal bactericidal concentration of 10 μg ml-1. The biosensor based on c-Ag/rGO exhibits rapid and sensitive response for uric acid detection with a detection limit of 0.025 μM, a sensitivity of 5.76 μA mM-1 and a wide linear range of 0.025 ∼ 2250 μM. The comparative analysis with relevant nanocomposites also reveals the precedence of c-Ag/GO in these applications, thus highlighting the advantages of the developed preparation method for c-Ag/GO.

Hybrid hydroxyapatite (HAP) microparticles with a hollow HAP core and a chitosan/hyaluronic acid (CHI/HA) multilayer shell were fabricated via the hydrothermal method and the layer-by-layer (LbL) self-assembly technique. Depending on the hydrothermal reaction time, the thickness of the HAP shell could be controlled and the size of the hybrid hollow microparticles varied between 850 nm and 2 μm. The size and HAP shell thickness significantly affect the drug release property of the resulting hybrid microparticles. The DOX release results demonstrated that CHI/HA multilayers could potentially assuage the initial burst release of drug from the porous HAP matrix because the polymer multilayer shell acted as a barrier to control the exchange of the drug. In addition, the drug release of hollow hybrid HAP microparticles was pH-dependent because of the different electrostatic interaction in the CHI/HA multilayers at different pH values and the dissolution of the HAP hollow core under acidic conditions. The present paper provides a facile and green route for the fabrication of hierarchical hybrid drug carriers with controllable size, wall thickness and drug release properties by combining natural polyelectrolytes and hollow HAP microparticles, which is highly attractive for controllable drug delivery.

Large nonlinear optical (NLO) coefficient and good stability, two essential factors to evaluate second-order NLO materials, are difficult to be achieved in one molecule simultaneously. Herein, by utilizing the concept of “isolation chromophore”, “isolation group” and dendritic structure, a dendritic molecule D-NS and a dendronized hyperbranched polymer DHP-NS are prepared to investigate their structure-property relationship. For the small dendritic molecule D-NS, it exhibits a high d33 value of 140 pm/V. But this value can be easily dropped when the temperature is higher than 50 °C, which extremely limits its real application. After introducing D-NS into a dendronized hyperbranched polymer chains, the obtained DHP-NS also shows a high d33 value of 101 pm/V, but much better stability than D-NS. Even when its thin film was heated to 120 °C, no obvious decay can be observed in the d33 value of DHP-NS. This work demonstrates an effective strategy to realize both large NLO effect and good stability simultaneously.

High adsorption capacity and selectivity of microprous carbon are critical for exceptional post-combustion CO2 capture ability. Herein we report a novel strategy to prepare N-doped microprous carbon with high surface area (2363 m2 g−1 for CPTHB-7), narrow pore size distribution and high ultramicropore ratio (

Currently, it remains a great challenge to achieve all-solid-state supercapacitors with both high electrochemical performance and excellent stretchability because of the limitations of stretchable electrodes and solid-state electrolytes. Here, we developed all-solid-state supercapacitors by using aligned carbon nanotube/conducting polymer (Ag-doped poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate)) composites as electrodes and polyvinyl alcohol-based electrolytes. The obtained all-solid-state supercapacitors not only exhibited a high specific capacitance of 64 mF cm−2 (corresponding to 85.3 F g−1), but could also maintain 98% of their original capacitance even under a tensile strain as high as 480%, which represents the highest value for thin-film all-solid-state supercapacitors using the same electrolyte to date, to the best of our knowledge. The newly developed thin-film supercapacitor maintained 90% of its original capacitance after 100 stretching cycles to a tensile strain of 400% and maintained 93% after stretching to 200% for 2000 cycles, indicating excellent stretching stability. The present work provides an efficient strategy to achieve highly stretchable energy storage devices with high performance.

Thermally activated delayed fluorescent (TADF) polymers are suitable for solution-processed organic light-emitting diodes (OLEDs). However, so far, very few efficient TADF polymers have been reported, which severely limits their commercial application in display and lighting fields. Furthermore, most of the reported TADF polymers are synthesized by the polymerization of low-molecular-weight monomers, which may require complicated modification process or present high steric hindrance resulting in low-molecular-weight polymers. In this work, a series of yellow-green TADF polymeric emitters PTPA-mCP-PxzTrz-X (X = 10, 20, 30, or 40) were designed and synthesized by grafting TADF emitter phenoxazine-triphenyltriazine (PxzTrz) and host unit 1,3-bis(9H-carbazol9-yl)benzene (mCP) onto the pre-obtained triphenylamine-carbazole alternating copolymers. All polymers displayed good solubility and thermal stability. By employing PTPA-mCP-PxzTrz-40 as non-doped emissive layer, the device displayed a maximum luminance of 650.7 cd/m2 and a maximum current efficiency of 3.3 cd/A, which is promising for commercial application.

The construction of a 3D graphene-based hybrid electrode with an optimized porous structure remains an attractive topic. Herein, we used the highly conductive graphene hydrogel (GH) with a well-defined 3D macroporous structure as a support to electrodeposite polyaniline (PANI), aimed to improve the energy density of GH-based capacitor electrode without deteriorating its high power capability. The as-prepared GH/PANI heterostructure with thin PANI layer conformally coated on the GH framework totally retains the native hydrogel pore structure and its high surface area, which facilitates the effective electron and ion transport within the electrode and thus endows GH/PANI composite electrode with excellent electrochemical properties such as a specific capacitance of 710 F g−1 at 2 A g−1 and 73% capacitance retention upon a current increase to 100 A g−1. Moreover, the assembled symmetric supercapacitor device based on GH/PANI heterostructure electrode delivers a maximum energy density and power density of 24 W h kg−1 and 30 kW kg−1, respectively, and also exhibits a good cycling stability with 86% capacitance retention after 1000 cycles. These findings demonstrate the importance and great potential of GH-based heterostructure in the development of high-performance energy-storage systems.

In this paper, a pH-/thermal-/NIR multi-responsive drug delivery platform based on hollow hydroxyapatite (H-HAP), poly(N-isopropylacrylamide- co-acrylic acid) (PNA) and gold nanorods (AuNRs) were prepared via electrostatic self-assembly. Thermal-sensitive PNA and near-infrared (NIR) responsive AuNRs were capped on the surface of mesoporous hollow HAP to obstruct the initial burst release of HAP and endow the vehicles with multi-responsive drug delivery properties. Notable pH-/thermal-/NIR multi-responsive drug release properties were clearly observed for H-HAP/PNA/AuNRs hybrid microcapsules. In addition, relatively high DOX release could be found for H-HAP/PNA/AuNRs hybrid microcapsules at pH 4.5 upon NIR laser irradiation, due to the corrosion of H-HAP in acidic media and the synergistically photothermal effect between AuNRs and PNA. This study provides a feasible method to fabricate intelligently controllable hybrid drug carriers, which shows great potential in controllable drug delivery.

Conjugated polymers bearing pendant bipyridine groups, PM1PT-x , were synthesized in high yield from a carefully designed dibromocarbazole monomer M1 using a Suzuki coupling reaction with a phenothiazine diborate monomer. PM1PT-x , where x is the mole percentage of M1 in the total feed of dibromo-monomers and varied to levels of 25%, 50%, 75% and 100%, was reacted with a ruthenium complex to yield conjugated polymers bearing pendant bipyridine ruthenium complexes, PM1PT-x-Ru . The introduction of ruthenium complexes extended the absorption of PM1PT-x-Ru to the visible light region. Furthermore, these polymers demonstrated sufficient stability and suitable energy levels to potentially be highly efficient photoactive materials for polymeric solar cells.

Balanced strength and toughness is always the goal of high-performance polymer materials for practical applications. In this work, a series of transparent poly(lactic acid) (PLA) nanocomposite films incorporated with fully exfoliated octadecylamine-functionalized graphene (ODAG) as effective nanofiller were prepared by solution blending and casting method. Because of the good hydrophobic compatibility between ODAG and PLA, a homogeneous dispersion of ODAG into PLA matrix and improved interfacial adhesion between them can be achieved. The obtained PLA/ODAG nanocomposite films present markedly improved crystallization behavior, mechanical properties and thermal stability. Compared to neat PLA, the nanocomposite films show a 34% increase in tensile strength, 44% increase in Young’s modulus, and 300% improvement in tensile toughness by the addition of only 0.4 wt% of ODAG. The simultaneous improvement in both strength and toughness could be attributed to homogeneous dispersion of ODAG in PLA matrix, improved interfacial interaction due to unique interphase structure, as well as enhanced crystallization.

In this work, aliphatic poly(urethane-amine) (PUA) grafted mesoporous hollow hydroxyapatite (H-HAP) microparticles were prepared via in situ polymerization in supercritical CO2. Thermal-responsive PUA acted as the on–off gates inside the mesoporous H-HAP due to the stretch and shrinkage of the PUA polymer chains at different temperatures. The PUA-grafted hollow HAP (PUA-g-H-HAP) microparticles displayed high specific surface area (95 m2 g−1) and drug loading efficiency (60%). The in vitro drug release studies indicated that PUA-g-H-HAP microparticles exhibited distinguishable pH- and thermal-dependent drug release properties, and PUA on–off switches enabled the DOX release in a reversible way by simply adjusting the environmental temperature. Moreover, compared to the hollow HAP microparticles having a higher amount of released DOX over the initial 2 h (about 24.4% of total released drug over 24 h) at 37 °C and pH 7.4, PUA-g-H-HAP microparticles displayed a sustained release property with the value of only 10.7% deriving from the blockage of the stretched PUA chains inside the mesoporous H-HAP.

Well-defined α-fluorinated alkyl ester, ω-carboxyl telechelic polystyrenes (PS) were synthesized via combining aminolysis of RAFT-polystyrene and thiol–ene “click” reaction simultaneously. The perfluoroalkyl end groups were –CF3, –(CF2)2–CF3 and –(CF2)7–CF3, respectively. Highly ordered porous films of such telechelic PS with an average pore size about 1.00 μm were fabricated via a static breath-figure process. With the content of fluorine on the surface of porous films increasing from 1.04 wt%, to 1.64 wt% and 2.97 wt%, respectively, the water contact angle (WCA) of such porous films increased from 112° to 116° and 121° ± 0.4°, respectively, indicating their hydrophobicity. Interestingly, microspheres with average diameters of ca. 0.30–0.65 μm can be fabricated via a static BF process using methanol instead of water as the vapor atmosphere in the glass vessel.

New polymethylene-based AB2 star polymers with well-defined architecture and various components were synthesized using a combination of polyhomologation of ylides and atomic transfer radical polymerization (ATRP). The chain structures of polymethylene-b-(polystyrene)2 (PM-b-(PS)2) and polymethylene-b-(poly(methyl methacrylate))2 (PM-b-(PMMA)2) were characterized through 1H NMR, GPC and FT-IR. The porous films of such star copolymers were fabricated via a static breath-figure (BF) process. The influence of polymer molecular weight, solution concentration and environmental temperature on the morphology of such block copolymer films was investigated. The porous surface of such a film presents hydrophobic behaviour with a static water-droplet contact angle of ca. 108°. The electrospinning of PM-b-(PS)2 was performed using CHCl3 as a solvent and the wrinkle-like polymer particles with nanopores on their surface were obtained.

A thiol–ene “click” reaction proceeds with facile reaction conditions for complete conversion, and displays a higher tolerance to various backbones and functional groups compared with traditional coupling and functionalization strategies. Herein, well-defined α,ω-telechelic polystyrenes with trithiocarbonate and carboxyl terminal groups (PS-CTA) were firstly synthesized via reversible addition-fragmentation chain transfer (RAFT) radical polymerization. Then, the terminal thiol group was converted from the thiocarbonylthio end group of PS-CTA and subsequently reacted with n-butyl acrylate and vinyl ferrocene, respectively, through thiol–ene “click” chemistry, to achieve α,ω-telechelic polystyrenes with difunctionality. Alternatively, a facile one-pot simultaneous aminolysis and thiol–ene “click” reaction using PS-CTA and various ene-bearing compounds as reactants was found to have high efficiency in synthesizing diverse α,ω-telechelic polystyrenes with di- and tri-functionality. Various functional groups such as hydroxyl, acrylate, fluorinated acrylate, ferrocene and allyl, etc. can be successfully incorporated as terminal groups of α,ω-telechelic polystyrenes.

Organic–inorganic hybrid materials have received great interest in the last 10 years in the controlled drug delivery area because of their excellent biocompatible, biomimetic, and pH-sensitive properties. Biomineralization is a biomineral-inspired route to prepare novel organic–inorganic hybrids, which involves a diffusion-controlled deposition of inorganic minerals within porous polymeric matrices. Proper combination of controlled biomineralization technique with the rational choice of polymer templates would lead to the successful development of smart self-assembled drug carriers. The present work mainly summarizes our recent work about the biomineralized organic–inorganic hybrid materials aiming for smart drug delivery including hybrid beads, membranes, and micro/nano gels. Furthermore, prospect for future development of the smart organic–inorganic hybrids is also discussed.

A new approach to the facile preparation of high-performance composite membrane for solvent resistant nanofiltration is presented herein. Within the composite membrane, hydrophilic polyethyleneimine (PEI) and hydrophobic hydroxyl terminated trifluoride polydimethylsiloxane (PDMS) are cross-linked as skin layer, whereas polyacrylonitrile (PAN) ultrafilitration membrane serves as support layer. The microstructure and physicochemical properties of the membrane are extensively investigated. It is found that PEI chains and PDMS chains are covalently cross-linked via trimesoyl chloride through interfacial polymerization, generating hydrophilic–hydrophobic hybrid network. The cross-linking inhibits the chain mobility of PEI, affording the composite membrane enhanced thermal and mechanical stabilities relative to the membrane without PDMS. Combining the advantages of both hydrophilic and hydrophobic materials endows the composite membrane with excellent solvent resistance properties and nanofiltration performances in both polar solvents and nonpolar solvents, such as isopropanol, butanone, ethyl acetate, and n-heptane. Particularly, the composite membrane achieves permeate fluxes of 37.8, 3.5, 5.4, and 4.7 L m−2 h−1 for these four solvents, respectively, along with the area swellings below 3.2%. After being equilibrated in these solvents, the composite membrane exhibits good structural stability with molecular weight cut-off of 600. The operation stability of the composite membrane is also explored.

Aiming to obtain effective calix[4]resorcinarene (CRA)-based photorefractive (PR) materials, three star polymers CRA-PCAH4, CRA-PCAH8 and CRA-PCAH4-PCH4 were prepared via a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and click reaction. CRA-PCAH4 and CRA-PCAH8 bearing only carbazole-azo-nitrobenzene-based polymeric arms exhibited poor solubility in low boiling point solvents because of the strong interchain electrostatic interactions. While the miktoarm star polymer CRA-PCAH4-PCH4, which was prepared based on CRA-PCAH4 by introducing some carbazole-based polymer arms (PCH) as buffering chains to isolate the nonlinear optical (NLO) components in the CRA core, exhibited good solubility in tetrahydrofuran (THF). A composite based on CRA-PCAH4-PCH4 showed much better PR performance than that of the corresponding PCAH arm tested via a two-beam coupling (TBC) experiment under zero electric field without pre-poling.

The double stimuli responsive water-soluble poly(urethane amine)s are prepared under supercritical carbon dioxide (scCO2) with renewable resources—carbon dioxide and natural α-amino acids—as the starting materials. The urethane content, which will decide on the thermosensitive behavior of poly(urethane amine)s, is regulated not only by the substituent on aziridine derivatives but also by the coordinated metallic ion of Salen-metal complexes as a catalyst. Interestingly, the thermosensitive reversibility is also changed through the application of Salen-metal complexes in the copolymerization reaction of CO2 with aziridine derivatives. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Poly(N-isopropylacrylamide) (PNIPAAm)/calcium carbonate (CaCO3) micro/nanohybrid composites with smart drug-delivery property had been prepared via in situ biomineralization reaction. Sodium poly(styrene sulfonate) (PSS) was used as the crystal growth additive to control the crystalline polymorph of CaCO3 and the morphology of the hybrid materials. The interaction between PSS and Ca2+ contributed to the formation of hierarchical micro/nanohybrid composites, in which microscale vaterite microparticles were covered by nanoscale PNIPAAm micelle. Vitamin B2 (VB2) release behavior was found to be pH- and thermal-responsive. Moreover, the release profiles were sustained with the introduction of CaCO3 microparticles, suggesting that CaCO3 microparticles could hinder the permeation of the encapsulated VB2 and reduce the drug release effectively. The prepared micro/nanohybrid materials can be used as “smart” hierarchical materials for controlled drug delivery. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

To improve the mechanical strength of natural hydrogels and to obtain a sustained drug-delivery device, temperature-/pH-sensitive hydrogel beads composed of calcium alginate (Ca-alginate) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared in the presence of poly(sodium acrylate) (PAANa) with ultrahigh molecular weight (Mη ≥ 1.0 × 107) as a strengthening agent. The influence of PAANa content on the properties, including the beads stability, swelling, and drug-release behaviors, of the hydrogels was evaluated. Scanning electron microscopy and oscillation experiments were used to analyze the structure and mechanical stability of the hydrogel beads, respectively. The results show that stability of the obtained Ca-alginate/PNIPAAm hydrogel beads strengthened by PAANa the alginate/poly(N-isopropyl acrylamide) hydrogel bead (SANBs) was significantly improved compared to that of the beads without PAANa (NANBs) at pH 7.4. The swelling behavior and drug-release capability of the SANBs were markedly dependent on the PAANa content and on the environmental temperature and pH. The bead sample with a higher percentage of PAANa exhibited a lower swelling rate and slower drug release. The drug release profiles from SANBs were further studied in simulated intestinal fluid, and the results demonstrated here suggest that SANBs could serve as a potential candidate for controlled drug delivery in vivo. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

trans-Dichlorotetrapyridineruthenium(II) [trans-RuCl2(py)4] was synthesized and the structure was determined by single crystal X-ray crystallography. Highly efficient formation of propylene carbonate (PC) from carbon dioxide and propylene oxide was achieved by using a catalyst system composed of trans-RuCl2(py)4 and hexadecyl trimethyl ammonium bromide under mild conditions (4h, 80 °C, 3.0 MPa). PC was obtained in nearly 100% selectivity without the formation of a polymer. The catalyst could be recycled constantly many times without any significant loss of its catalytic activity. On the basis of the results, a mechanism for the reaction was proposed. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.

The crystallization and melting behavior of flame sprayed Polyamide 1010 (PA1010) containing zirconium dioxide (ZrO2) were investigated using differential scanning calorimeter (DSC). ZrO2 has a heterogenous nucleation effect on PA1010, leading to a moderate increase in the crystallization temperature and a decrease in the supercooling temperature. A modified Avrami theory could be successfully used to well describe the early stages of non-isothermal crystallization of PA1010 and its composite coatings. A study of the nucleation activity, which indicated the influence of the filler on the polymer matrix, revealed that the zirconium dioxide nanoparticles had a good nucleation effect on PA1010. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers.

Several polymers containing triphenylene moieties in main chain were synthesized by Knovenagel or Wittig condensations. The polymers were characterized by 1 H NMR, IR, GPC, TG, UV–vis, FL and CV. Results indicated that PNB, which was prepared from the polycondensation of 4,4′-dialdehyde-4″- n -butyltriphenylamine with 1,4-bis(triphenylphosphonionmethyl)benzene dibromide, is the most thermally stable one and that PNP, which was prepared from the polycondensation of 4,4′-dialdehyde-4″- n -butyltriphenylamine with p -phenylene diacetonitrile, is the most thermally instable one. The fluorescence quantum efficiency of PNB is 94.3%, which is a high value for optoelectronic polymer materials. All the polymers have a similar CV curve with a reversible oxidation peak and two reduction peaks except that PNB has a single reduction peak.

Polyamide1010 (PA1010) and its composite with nanometer-sized zirconia (PA1010/nano-ZrO2) coatings were deposited using a flame spray process. The kinetics of nonisothermal crystallization of PA1010/nano-ZrO2 composite coatings was investigated by differential scanning calorimetry (DSC) at various cooling rates. Several different analysis methods were used to describe the process of nonisothermal crystallization. The results showed that the modified Avrami equation and Mo's treatment could describe the nonisothermal crystallization of the composite coatings very well. The nano-ZrO2 particles have a remarkable heterogeneous nucleation effect in the PA1010 matrix. The values of halftime and Zc showed that the crystallization rate increased with increasing cooling rates for both PA1010 and PA1010/nano-ZrO2 composite coating, but the crystallization rate of PA1010/nano-ZrO2 composite coating was faster than that of PA1010 at given cooling rate. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

In this work, smart hollow microcapsules made of thermal-/pH-dual sensitive aliphatic poly(urethane-amine) (PUA), sodium poly(styrenesulfonate) (PSS), and Au nanoparticles (AuNPs) for interdependent multi-responsive drug delivery have been constructed by layer-by-layer (LbL) technique. The electrostatic interactions among PUA, PSS, and AuNPs contribute to the successful self-assembly of hollow multilayer microcapsules. Thanks to the shrinkage of PUA above its lower critical solution temperature (LCST) and the interaction variation between PUA and PSS at different pH conditions, hollow microcapsules exhibit distinct pH- and thermal-sensitive properties. Moreover, AuNPs aggregates can effectively convert light to heat upon irradiation with near-infrared (NIR) laser and endow the hollow microcapsules with distinct NIR-responsiveness. More importantly, the NIR-responsive study also demonstrates that the microcapsule morphology and the corresponding NIR-responsive drug release are strongly dependent on the pH value and temperature of the media. The results indicate that the prepared hollow PUA/PSS/Au microcapsules have the great potential to be used as a novel smart drug carrier for the remotely controllable drug delivery. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43008.

A novel carbazole–triphenylamine copolymer-bearing pendant bipyridine PM1TPA and corresponding europium (III) complexed polymer PM1TPA–Eu–x, in which the values of x are 0.1, 0.5, and 1.0 representing the molar ratio of bipyridine ligands complexed with Eu(III), were designed and synthesized. Their chemical structures were confirmed by 1H NMR, FT-IR, and elemental analysis. Both PM1TPA and PM1TPA–Eu shows good solubility in common organic solvents such as tetrahydrofuran (THF) and CHCl3. The 5% weight loss temperature (Td5%) of PM1TPA and PM1TPA–Eu–1.0 are 363oC and 306oC, respectively. The photoluminescence (PL) spectra of PM1TPA–Eu in solution consists of two emission bands, one in the 400–570 nm region and another at 612 nm, corresponding to the emission of polymer main chain and europium complexes, respectively. When the concentration of PM1TPA–Eu–1.0 in THF solution increases, the PL intensity in the 400–570 nm regions became more and more weaker. And only the characteristic emission of europium complex was observed in the solid film, which indicates that the excited energy absorbed by the polymer backbone was efficiently transferred to the europium complexes. Furthermore, nearly monochromatic red electroluminescence from europium complex was observed from the polymeric light-emitting diode using PM1TPA–Eu–1.0 as the emissive layer under 25 V forward bias. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42746.

A carbazole-based photorefractive polyphosphazene was prepared via post-azo-coupling reaction. The polymer shows a low glass transition temperature of 50 °C, and has an excellent solubility in common organic solvents, which can easily be fabricated into an optically transparent film with long-term stability. The nonlinear optical effects, including two-beam-coupling and four-wave-mixing, were studied at 633 nm under room temperature. A gain coefficient of 79 cm −1 and a diffraction efficiency of 18% were observed at zero external electric field without any added plasticizer or sensitizer.

A quaternary copolyimide containing perylene, fluorene and oxadiazole units in the backbone, named as OPFF x , was designed and synthesized by a one-step polycondensation under high temperature. The successful polymerization was proved by both elemental analysis and FT-IR spectra. Weight average molecular weight of the polymer was in the range of 2.02–3.09 × 10 4 as measured by GPC. OPFF x with low oxadiazole content has good solubility in common organic solvents such as chloroform and tetrahydrofuran. Thin film of OPFF x could be prepared by directly spin-coating of its chloroform solution onto quartz glass. The polymer showed high thermal stability and the temperature of 10% weight loss was higher than 494 °C as measured by TGA in nitrogen, and no apparent glass transition temperature was observed from DSC measurement in nitrogen up to 350 °C. The film of OPFF x irradiated by ultraviolet light emitted strong reddish-orange fluorescence. Cyclic voltammetry measurement indicated that OPFF x could be easily reduced ( n -doped). Thus, the polymer may potentially be used as a thermal stable light-emitting and electron transporting material for light-emitting diodes.

A series of liquid crystalline copolyesters, possibly having auxetic behaviour, were designed and synthesized by solution polycondensation from 4,4′-(decanoxy) dibenzoyl chloride with 2,5-bis(p-alkoxy benzoyloxy) hydroquinone and 4,4′-dihydroxy-α,ω-diphenoxydecane in different ratios. All the polymers have lower melting point ranging from 80 to 140 °C, which is beneficial to the liquid crystalline state formation and the thermoplastic processing. The lateral rods derived from 2,5-bis(p-alkoxy benzoyloxy) hydroquinone monomer gave an obvious influence on properties of the resulting polymers, in which the liquid crystalline state stability and the solubility in common organic solvents were enhanced. Observations from POM and DSC indicated that all the polymers are thermotropic liquid crystalline with nematic characteristics.

Carbazole-based polymers bearing methine groups with low glass transition temperature ( T g ) for photorefractive purpose were prepared via postfunctionalization strategy. The successful reaction was identified by spectroscopic analysis and gel permeation chromatography. This approach is more facile compared with the direct polymerization from corresponding functional monomer. Chromophore content of the resulting polymers varied from 25% to 63% depending on the type of chromophore as calculated from 1 H NMR spectra. Molecular weight of the polymers are higher than 2.4 × 10 5 , and the polymers are easily soluble in common organic solvents like DMF and THF. T g of the polymers ranges from 40 to 58 °C depending on the structure of chromophore, and the polymers are relatively stable under 310 °C.

In this study, a novel nylon with long alkane segments (also called nylon 1313), which was synthesized using 1,13-tridecanedioic acid in our laboratory, has been characterized. Different rheological behaviors of nylon 1313 have been presented using steady shear, creep recovery, and dynamic tests. The time-temperature effects have also been investigated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1643–1651, 2005

Carbazole-based bi-functional photorefractive polymers with controlled azo group content were prepared via a post-azo-coupling reaction. The polymers were characterized by IR, 1 H NMR, UV–visible, DSC and GPC. Both IR and 1 H NMR results proved that the azo group was attached to the polymer. As shown by UV–visible spectrum measurement, the azobenzene chromophore contents increased with extending the post-azo-coupling reaction time, and changed from 14% to 67% when the reaction time extended from 6 to 60 h. Molecular weight ( M w ) of the polymers can reach 2.5×10 4 as measured by GPC, which is much larger than the polymers with similar structure prepared by direct polymerization from the corresponding functionalized macromonomers. Glass transition temperature ( T g ) of the polymers increased with the azobenzene chromophore contents.

The excellent synergistic effect of physical/mechanical properties of polyurethane/epoxy (PU/EP) interpenetrating polymer network (IPN) and the validity of nanofilling have one potential to improve the wear resistance of polymeric materials. With the aim of practical application, PU/EP IPN nanocomposites are prepared with nanodiamond (ND) as a reinforcing additive. Results showed the uniform thermal stability and the excellent compatibility between PU and EP in ND-hybridized PU/EP IPN. Simultaneously, ND particles work as crosslinked points improving the physical/mechanical properties of ND-hybridized PU/EP IPN, especially the wear resistance. The measurement of tribological property and the scanning electron microscope indicated that the wear resistance is able to be improved a lot by the formation of IPN and by the addition of ND. Consequently, the tribological mechanism of PU/EP IPN nanocomposites comes into being. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40244.

Toughened polypropylene with balanced rigidity (TRPP) was prepared by thermal mechanical blending of PP resin with a toughening master batch (TMB) in a twin screw extruder. The dependence of the mechanical properties of TRPPs on the ratio of ethylene-propylene to styrene-butadiene elastomers, the total elastomer content in the TRPP, and the amount of elastomers in the TMB were investigated. The TRPP with a total elastomer content of 14 wt %, which was made from a TMB with 32 wt % elastomer and a 80/20 (w/w) ratio of ethylene-propylene to styrene-butadiene elastomers, was found to have excellent balanced mechanical properties. The notched Izod impact strength at 23°C was 762 J/m (23 times that of PP), the flexural modulus was 1078 MPa (92% of that of PP), and the tensile strength at yield was 34.8 MPa (88% of that of PP). Moreover, its mechanical properties were much better than the simply blended sample with the same composition, demonstrating that dynamic vulcanization and polymer-bridge conjunction are excellent techniques to produce a high-impact, high-modulus PP. A sharp brittle–ductile transition was found at 14 wt % total elastomer content, which was assumed to be a percolation phenomenon. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1345–1350, 2001