Constructing an ion‐oriented channel on a zinc electrode through surface engineering

The inherent shortcomings of a zinc anode in aqueous zinc‐ion batteries(ZIBs)such as zinc dendrites and side reactions severely limit their practical application.Herein,to address these issues,an ion‐oriented transport channel constructed by graphdiyne(GDY)nanowalls is designed and grown in situ on the surface of a zinc electrode.The vertically stacked GDY nanowalls with a unique hierarchical porous structure and mechanical properties form a nanomesh‐like interface on the zinc electrode,acting as an ion‐oriented channel,which can efficiently confine the segmented growth of zinc metal in microscopic regions of hundreds of nanometers.In those microscopic regions,the uniform domain current density is effortlessly maintained compared with a large surface area,thereby inhibiting zinc dendrites effectively.Besides,due to the presence of the ion‐oriented channel,the modified zinc anode demonstrates long‐term stable zinc plating/stripping performance for more than 600 h at 1 mAh cm^(−2)in an aqueous electrolyte.In addition,full‐cells coupled with MnO2 show high specific capacity and power density,as well as excellent cycling stability with a capacity retention of 82%after 5000 cycles at 1 A g^(−1).This work provides a feasible and accessible surface engineering approach to modify the electrode interface for confined and dendrite‐free zinc deposition in aqueous ZIBs.

RECTIFYING EFFECT OF POLYANILINE(PANI)/N-TYPE POROUS SILICONE HETEROJUNCTION

Heterojunctions between polyaniline (PANI) and n-type porous silicon (PS), Al/PS-PANI/Au cell, were fabricated, and the rectifying parameters of this heterojunction diode were measured as a function of the preparation conditions of PANI and PS, the electronic structure of PANI as well as cell structure. The rectifying parameters of Al/PS-PANI/Au cell were determined to be gamma = 1.8x10(1) similar to 1.0x10(5) for the rectifying ratio at 3V, n = 3 similar to 12 for the ideal factor, j(0) = 8.0x10(-5) similar to 5.6x10(-2) mA/cm(2) for the reversed saturated current density, and phi(0) = 0.67 similar to 0.83 V for the barrier height, respectively. The best rectifying heterojunction diode made between PANI and n-type PS with higher rectifying factor (gamma = 1.0x10(5) at 3V), output current (>1500 mA/cm(2) at 3V) and lower ideal factor (n = 3.3) was obtained by preventing the oxidation of PS before evaporating Al electrode.

FERROFLUID CONTAINING SOLUBLE CONDUCTIVE POLYANILINE AND ITS FREESTANDING FILMS

Ferrofluid containing highly conductive polyaniline (PANI) was prepared, in which soluble PANI solutions dopedwith 10-camphorsulfonic acid (CSA) and dodecyl benzenesulfonic acid (DBSA) were used as the basic solution and Fe_3O_4nanoparticles (d = 10 nm) as the magnetic material. Moreover, the freestanding films of the resulting ferrofluid can beobtained by an evaporation method. The electrical and magnetic properties of the ferrofluid or its films can be adjustedthrough changing the content of PANI and Fe_3O_4. High saturated magnetization (≈ 30 emu/g) and high conductivity(≈ 250 S/cm) of the composite films can be achieved when the composite film contains 26.6 wt% of Fe_3O_4. In particular, itwas found that the composite films exhibit a super-paramagnetic behavior (Hc = 0) attributed to the size of Fe_3O_4 particles on the nanometer scale.

Fluorescence Spectra of Model Compounds for Light-emitting Alternating Copolymers in Heterogeneous Environments

In this paper, the fluorescence spectra of model compounds of light-emitting alternating copolymers. M (TPA-PPV) and M (TPA-PAV) (Scheme 1) were studied and the effect of KNO3 on the interaction between model compounds and ionic micelle-watts interface was also investigated. It is found that (I) The fluorescence changes of M (TPA-PPV) are related to the state of CTAB and SDS solution. (II)Aggregated state can be formed in M (TPA-PAV) solution at low concentration of CTAB. (III) Higher concentration of KNO3 may affect the interaction between model compounds and ionic micelle-water interface.

HETEROJUNCTION DIODES OF POROUS SILICON WITH SOLUBLE POLYANILINE

Two kinds of heterojunction diodes of porous silicon (PS) with soluble polyaniline (PANI) were fabricated. One is a heterojunction diode of PS with water-soluble copolymer of polyaniline (PAOABSA), Al/PS-PAOABSA/Au cell as rectifying diode. Another is a heterojunction diode of PS with soluble polyaniline doped with DBSA, Al/PS-PANI (DBSA)/Au cell as light emitting diode (LED). The rectifying characteristics of the rectifying diodes were measured as a function of the degree of sulfonation and thickness of the copolymers, as well as oxidation of PS. The rectifying ratio of the heterojunction can reach 5.0x10(4) at +/-3 V bias. For the LED, the photoluminescence (PL) and electroluminescence (EL) spectra were measured and discussed.

NONLINEAR OPTICAL PROPERTIES OF X-TYPE CHROMOPHORES AND THEIR DOPED FILMS

Two X-type chromophores, 2-[4-(4,5-di(4-nitrophenyl) imidazolyl) phenyl]-4,5-di(4-methoxyphenyl)-imidazole (DNPIPDMOPI), 2-[4-(4,5-di(4-nitrophenyl)-imidazolyl) phenyl]-4,5-di(4-aminophenyl)-imidazole (DNPIPDAPI), were synthesized and characterized. The results show that they possess good nonlinearity, considerable blue-shifted absorption (385 nm and 379 nm in THF) and high decomposition temperature (377 'C and 405 'C). These mean that the X-type chromophores possess a rather good nonlinearity-transparency-thermal stability trade-off. The multi-step corona-poling technique at elevated temperature and in-situ SHG measurements were used to obtain and evaluate the poled films of these chromophores doped in PMMA. The largest SHG signals appeared at 110-120°C, which are 12.5 pm/V and 16.7 pm/V respectively. The dependence of poling induced orientation stability on temperature was measured by depoling experiments and the results indicate that the poling-induced orientation of the films is stable at about 100°C. Theoretic analyses imply that better orientation stability arises from the X-type structure of chromophore. The X-type chromophore has two crossed intramolecular CT, both β xxx and β xyy can contribute to the second-order susceptibility, and the ratio of the tensorial components (γ= β xyy /β xxx ) is about 1/3, so the orientation decay of the films induced by rising temperature will provide a certain compensation for the contribution of β xyy of chromophores.

Recent progress in stretchable organic field-effect transistors

Stretchable organic field-effect transistors (STOFETs) employing organic semiconductors as active layers are highly attractive ongoing from health monitoring to biological research owing to some favorable advantages over their inorganic counterpart, including light weight, low cost, solution processing, high flexibility and simple adjustment of functionalities through molecular design. Although the development of STOFETs with original electrical performances under large mechanical deformation remain rudimentary, major efforts have recently been devoted to the investigation on STOFETs, and remarkable advances in stretchable components and novel fabrication methods have been achieved. A detailed overview of the advantages, challenges and current achievements in STOFETs was given including stretchable electrodes, semiconductors, dielectrics and substrates. Furthermore, conclusions and prospects for the future development of STOFETs with both high stretchability and superb electrical performances fabricated using intrinsically stretchable components are proposed.

The preparation of whole sp-C composed alkyne rich carbon materials

For the high content of sp-hybridized carbon atoms,carbyne based materials can express superior conductivity and ultra-high theoretical capacity,which are key factors of high-performance anode.However,the poor stability of synthetic intermediates and unwanted side reactions lead to huge challenge to synthesis carbyne alternating carbon–carbon triple and single bonds.Here,we rationally designed a smart“Greedy Snake”strategy to synthesize the alkyne rich carbon materials named Si capped alkyne rich carbon(Si-Alkyne-C)which comprised of sp-hybridized carbon atoms.The as-prepared Si-Alkyne-C generated on the copper surface through a carbon–carbon coupling,in which Si can effectively protect the intermediates generated by the reaction.The C–Si bond can constantly generate copper-alkyne intermediates to couple with other terminal alkynes to continuously elongate like"Greedy Snake",forming a long alkyne chain structure.The as-prepared Si-Alkyne-C can be applied as anode electrodes,exhibited very high reversible capacity of up to 2776 mAh/g at a current density of 50 mA/g and an average capacity around 1202 mAh/g at a high current density of 5000 mA/g for 5000 cycles,which are the best results among the reported carbon materials and better than many other anode materials.These results not only provide a facile strategy to prepare carbyne based materials,but also open a broad avenue for the preparation of high-capacity anode materials.

Tetrathiafulvalene (TTF)-based gelators:Stimuli responsive gels and conducting nanostructures

Tetrathiafulvalene (TTF) and its derivatives have been intensively investigated for conducting materials for more than 30 years.As π-electron donors,TTF and its derivatives can be reversibly transformed into the respective TTF.+ and TTF2+.Due to its reversible feature,the TTF unit has been widely employed as the building block for switchable systems.In recent years studies of conducting nanostructures of TTF derivatives have received more and more attention.One simple way to prepare nano-structures is through the gelation processes.In this review,we have discussed recent progress in stimuli-responsive gels and conducting nanostructures based on TTF-based gelators.

Molecular-based conducting magnet

Molecular-based conducting magnet or magnetic conductor, is an overlap of organic conductor and molecular magnet. Due to the existence of ferromagnetism, antiferromagnetism and quantum magnetism in insulated charge-transfer salt, it becomes a common sense that magnetism is not good for conductivity. After the discovery of first molecular-based metallic ferromagnet, molecular-based conducting magnet with n-unit from organic conductor and magnetism from coordination counterion became a hot area. The metallic ferromagnet, semiconductor room-temperature ferrimagnet, metallic weak ferromagnet and supercon- ducting antiferromagnet have been discovered. The new molecular-based conducting magnet with higher conductivity and higher magnetic ordering temperature is expected.

Incorporation of hydrogen-bonding units into polymeric semiconductors toward boosting charge mobility,intrinsic stretchability,and self-healing ability

The soft nature has endowed conjugated polymers with promising applications in a wide range of field-effect transistor(FET)based flexible electronics.With unremitting efforts on revealing the molecular structure-property relationships,numerous novel conjugated polymers with high mobility and excellent mechanical property have been developed in the past decades.Incorporating hydrogen-bonding(H-bonding)units into semiconducting polymers is one of the most successful strategies for designing high-performance semiconducting materials.In this review,we aim to highlight the roles of H-bonding units in the performances of polymeric FETs from three aspects.These include(i)charge mobility enhancement for semiconducting polymers after incorporation of H-bonding units into the side chains,(ii)the effects of H-bonding units on the stretchability of conjugated polymers,and(iii)the improvement of self-healing properties of conjugated polymers containing dynamic hydrogen bonds due to the H-bonding units in the side chains or conjugated backbones.

A high-efficiency solid-state dye-sensitized solar cell with P3HT polymer as a hole conductor and an assistant sensitizer

Poly（3-hexylthiophene） （PBHT） was used in a solid-state dye-sensitized solar cell （S-DSC） with a broad- absorption metal-free organic dye sensitizer 1,2,4,5-benzenetetracarboxylic acid （BzTCA）. Under full- sunlight irradiation （AM 1.5 G, 100 mW/cm2 ）, an overall conversion efficiency of 3.21% was achieved, which represents one of the highest efficiencies reported in an S-DSC. Our results indicate that the P3HT polymer is a promising material as both a hole conductor and an assistant sensitizer in the fabrication of solid-state DSCs.

A new gelator based on tetraphenylethylene and diphenylalanine:Gel formation and reversible fluorescence tuning

A new gelator 1 based on tetraphenylethylene(TPE) and diphenylalanine was designed and synthesized.Compound 1 was non-emissive in solution,but its fluorescence turned on after the formation of gels,due to the aggregation-induced emission(AIE) feature of TPE.Interestingly,the fluorescence was reversibly switched "on-off" upon the "gel-sol" transition.Scanning electron microscope(SEM),confocal laser scanning microscope(CLSM) and X-ray diffraction(XRD) were employed to study the gels.

Preparation of a novel self-assembling nonlinear optical (NLO) polymer film

A novel self-assembling crosslinking second harmonic generation nonlinear optical (SHG/NLO) film with high SHG coefficient (2×10-7 e.s,u.by IR dichroism) was prepared by morecular design and "in-situ poling and sol-gel process".The content of the NLO chromophore (S)-(-)-1-(4)-mtrophenyl-2-pyrrolidinemethanol (NPP) is as high as 50 mol% since NPP molecules probably disperse in the film at a molecular level The film is rigid,uni form and transparent.This designed clathrate supermolecular structure was poved by IR,atomic force microseopv (AFM) and differential scanning calorimetry (DSC) detection.The title film exhibits a long-term temporal stability with 95% of the initial value of SHG coefficient maintained even after 20 d at 65℃(by UV spectroscopy)

Molecular orbital study on antiferromagnetic coupling mechanism in a silver(Ⅰ)complex

The mechanism of antiferromagnetic coupling in an Ag (I) complex of nitronyl nitroxide is investigated by means of the broken-symmetry approach within the density functional method (DFT-BS). The magneto-structural corre-lation and the single-occupied molecular orbital (SOMO) analysis reveal the existence of the antiferromagnetic cou-pling pathway along nitronyl nitroxide units via Ag (I) ion, and that the Ag (I) ion plays an important bridge role. The spin population analysis also shows the existence of spin de-localization along the ONCNO-Ag-ONCNO chain. It is found that the non-typical covalent bonds with major ionic charac-ter between Ag (I) ions and oxygen atoms of nitronyl nitrox-ide units can be used to mediate the spin-spin interaction of nitronyl nitroxides.

Responsive Gels with the Polymer Containing Alternating Naphthalene Diimide and Fluorinated Alkyl Chains： Gel Formation and Responsiveness as Well as Electrical Conductivity of Polymer Thin Films

A new electroactive polymer 1 with alternating NDI （naphthalene diimide） moieties and fluorinated alkyl chains was prepared and characterized. Gels of polymer 1 were formed in several solvents. Interestingly, gels of polymer 1 exhibited responsiveness toward N2H4, F and CN . Absorption and ESR spectroscopic studies revealed that such responsiveness is owing to the reduction of NDI moieties into the respective NDI＇-. In addition, thin films of polymer 1 were easily prepared with spin-coating technique and the electrical conductivity of thin films reached 52.4 S/m after exposure to NeH4 vapor.

A New Pyrene-Spacer-Maleimide Dyad for Sensing Molecules with One or Two Thiol Groups

A new pyrene-spacer-maleimide dyad 1 was used to selectively detect cysteine in the presence of other amino acids, and sequentially react with dithiols to generate the molecule with two pyrene units showing typical excimer fluorescence. Accordingly, dyad 1 was able to differentiate molecules with one or two thiol groups.

Crystal Structures and Magnetic Studies of Naphthalene Derivatives Containing Nitronyl Nitroxides

Crystal structures of new nitronyl nitroxide derivatives 1, 2 and 3 were determined with X-ray diffraction analysis: 1, monoclinic, C-2/c, a = 1.204 (5) nm; b = 0.9730 (5) nm, c = 2.7049 (10) nm, beta = 98.189 (15)degrees, V = 3.2315 (24) nm(3), Z = 8; 2, orthorhombic, Pbca, a = 0.61262(2) nm, b = 1.11426(6) nm, c = 2.30543(13) nm, V = 1.57373(13) nm(3), Z = 4; 3, monoclinic, P2(1)/n, a = 0.64253(4) nm, b = 2.55003(17) nm, c = 1.15497(6) nm, beta = 95.000(3)degrees, V = 1.8852(2) nm(3), Z = 4. Their magnetic properties were measured with SQUID and analyzed based on their crystal structures with simple singlet-triplet, modified one dimensional antiferromagnetic chain and modified singlet-triplet models respectively: 1, J/k(b) = -2.5 K; 2, J/k(b) = 7.8 K, theta = 2.8 K; 3, J/k(b) = -0.96 K, theta = 0.21 K.

Fluoro-substituted DPP-bisthiophene conjugated polymer with azides in the side chains as ambipolar semiconductor and photoresist

Photoresists are essential for the fabrication of flexible electronics through all-photolithographic processes.Single component semiconducting photoresist exhibits both semiconducting and photo-patterning properties,and as a result,the device fabrication process can be simplified.However,the design of semiconducting polymeric photoresist with ambipolar semiconducting property remains challenging.In this paper,we report a single component semiconducting photoresist(PFDPPF4T-N_(3))by incorporating azide groups and noncovalent conformation locks into the side alkyl chains and conjugated backbones of a diketopyrrolopyrrole-based conjugated polymer,respectively.The results reveal that PFDPP4FT-N_(3) exhibits ambipolar semiconducting property with hole and electron mobilities up to 1.12 and 1.17 cm^(2) V^(−1) s^(−1),respectively.Moreover,field effect transistors with the individual photo-patterned thin films of PFDPP4FT-N_(3) also show ambipolar semiconducting behavior with hole and electron mobilities up to 0.66 and 0.80 cm^(2) V^(−1) s^(−1),respectively.These results offer a simple yet effective design strategy for high-performance single component semiconducting photoresists,which hold great potential for flexible electronics processed by all-photolithography.

Convenient Synthesis and Enhanced Second-order Nonlinear Optical Property of a Novel Hyperbranched Polymer

A novel hyperbranched polymer （3） was prepared by copolymerization of tri-aldehyde moieties with azo chromophores having two active methelene groups, from ＂A2＋B3＂ approach based on simple Kneovenagel reaction. For comparison, its analogue linear polymer （5） was also synthesized. The two polymers are soluble in common organic solvents, and exhibit good thermal stability. Interestingly, the hyperbranched polymer demonstrates dramatically enhanced second-order nonlinear optical property with comparison to its linear analogue.