Search

We report that the ultraviolet (UV) light induced photochromic behavior of layered organic-inorganic perovskite material of (C4H9NH3)2CuCl4, changed from yellow to brown after irradiation with UV light (10 mW/cm2) and partially recovered through storage in the dark. (C4H9NH3)2CuCl4 exhibited two distinct absorption bands centered at 286 nm (band I) and 384 nm (band II), which were attributed to the photo-induced exciton formed in 2D inorganic layers sandwiched by organic layers. The blue shift of band I from 287 to 269 nm as well as the decrease of the intensity of band I and band II could be found when samples were irradiated under UV light for different length of time. The simultaneous weakening of the intensity of the N-H⋯Cl hydrogen bond as well as the vibration of the long Cu-Cl bond in the distorted CuCl64− octahedron could be detected from the Fourier transform infrared (FTIR) spectra, which resulted the change of charge distribution of the dissymmetric Cl-Cu⋯Cl bond and the resulting photochromic behavior.

Based on the generalized Lorenz–Mie theory (GLMT), which provides the general framework and expansion of the incident shaped beam in terms of cylindrical vector wave functions, an analytic solution to the electromagnetic scattering by coated infinite cylinders is constructed for arbitrary incidence of a shaped beam. As an example, for a tightly focused Gaussian beam propagating perpendicularly to the cylinder axis, the scattering characteristics that obviously demonstrate the three-dimensional nature are described in detail, and numerical results of the normalized differential scattering cross section are evaluated.

The electroluminescence (EL) from tetramethyl ester of perylene-3,4,9,10-tetracarboxylic acid (TMEP)-doped poly(vinylcarbazole) (PVK) light-emitting diodes and their current-voltage characteristics were investigated. The results indicated that field-emission tunneling injection predominated in the ITO/TMEP:PVK/Al diodes at high applied voltages. With increasing the TMEP dopant density, the injection barrier for holes was slightly reduced. Under injection-limited conditions, the possible kinetic processes were discussed in view of the field evolution of the EL spectra and the energy level alignment in the diode configuration. With increasing the field intensity, different emission components varying their intensities in EL spectra indicates that both charge transfer and energy transfer occurred in TMEP-doped PVK layer. These transfer processes are influenced by varying the concentration of TMEP dopants as electron traps. The results indicate that the dynamic equilibrium among carrier recombination, charge transfer and energy transfer, can be adjusted by dopant concentration and external bias. This information helps to establish a design framework for host–dopant systems.

Stable, elastic and optical transparent microcapsules containing tetrachloroethylene as core material were prepared from gelatin, sodium dodecyl sulfate (SDS) and sodium carboxymethylcellulose (NaCMC) by complex coacervation method for electrophoretic display. Microcapsules were characterized by scanning electron microscopy, optical microscopy, and thermogravimetric analysis. It is suggested that SDS plays an important role during the process of microencapsulation, i.e. the existence of SDS increases the interaction between gelatin and NaCMC and facilitates the progress of complex coacervation. Because of the compact structure of the capsule wall, the microcapsules represent high thermal stability and good barrier property, both of which prevent core materials from penetrating outside the capsules.

Erbium bisphthalocyanine (HErPc 2 ) films comprised of one-dimensional (1D) organic nanowires were obtained by the electrophoretic deposition method from the mixed solutions of chloroform and trifluoroacetic acid containing the protonated HErPc 2 . Effects of the deposition voltage ( V d ) and the deposition time ( t d ) on the morphology of the films were studied by X-ray diffraction, UV–vis absorption and scanning electron microscope. The results revealed that the growth of 1D organic nanostructure could be conveniently controlled by tuning the deposition parameters of V d and t d . The influences of the annealing time and the annealing temperature were also investigated and the effect of time–temperature correspondence principle was found. The film growth mechanism was discussed for both stages of the electrophoretic deposition and the annealing process. Furthermore, the as-deposited HErPc 2 films showed interesting photoresponse in the near infrared (NIR) region, indicating the possibility for NIR photodetection application.

A new catalytic CC bond-forming reaction has been developed. Catalyzed by cheap and commercially available copper(II) bromide (CuBr2; 10 mol%), the reactions of α-electron-withdrawing group (EWG)-substituted ketene S,S-acetals with aldehydes or ketones in acetonitrile at room temperature gave a variety of densely functionalized coupling products in excellent yields (80–98%). Based on this catalytic process, coumarin derivatives were efficiently synthesized when salicylaldehydes were selected as the carbonyl components.

A spin-coated layer of poly(N-vinylcarbazole) (PVK) doped with tetra-methyl ester of perylene-3,4,9,10-tetracarboxylicacid (TMEP) is prepared, and the effects of dopant concentration and bias voltages on excitation mechanisms are studied through analyzing its emission characteristics. The investigation indicates that in photoluminescence (PL) cases energy and charge transfers between PVK and TMEP are cooperated for low dopant concentration, whereas the electroluminescence (EL) spectra imply that energy transfer is more important than charge trapping and transfer in these devices. For high dopant concentration, charge transfer is dominated in PL spectra but has a minor effect on EL spectra, and the external bias has less influence on the EL characteristics. A kinetic analysis is given to rationalize the experiment results.

A facile and efficient one-pot synthesis of 1,3-disubstituted pyridin-2( 1H)-ones is developed via a novel cascade reaction of readily available a-hydroxy-a-carbamoyl ketene S,S-acetals under Vilsmeier conditions (DMF/POCl 3 ), and a mechanism of this domino reaction is proposed.

An asymmetrical perylene diimide 3 , N -(4-methoxyphenyl)- N ′-(4-nitrophenyl)-perylene-3,4,9,10-tetracarboxylic diimide, was synthesized, and its self-assembly and dissociation behaviors in chloroform was studied in detail by UV–vis and fluorescence spectroscopies. The resulting unique helical nanostructures from 3 were proposed to be self-assembled via the cooperative actions of π–π stacking, steric hindrance and electrophile–nucleophile type pairing.

An inorganic−organic hybrid composite was prepared from a soluble N-dodecyl-N′-phenyl-3,4,9,10-perylenetetracarboxylic diimide (DOPP) and silicon nanoparticles (NPs). The silicon NPs were synthesized by a solution-phase method. Remarkable photoluminescence (PL) quenching was observed in the composite dispersed in a polymethyl methacrylate matrix. On the basis of the analysis of the PL quenching mechanism, it was demonstrated that a photoinduced electron transfer from silicon NPs to DOPP could occur in the composite. The photoconductivity of the composite was studied, and the photosensitivity enhancement of the composite was realized due to the photoinduced electron transfer between silicon NPs and DOPP.

Exciton diffusion in organic materials is crucial for designing and optimizing organic photovoltaic devices. This paper addresses the important complication of the choice of film thickness affecting measurement accuracy in the method of measuring exciton diffusion length from thickness-dependent photocurrent response in organic bilayer heterostructures. Based on the photocurrent model integrated with optical interference effect, the correlation between the exciton diffusion length and the optimal thickness of organic layer is analytically solved. It shows that the intrinsic nonlinearity of the correlation causes prominent uncertainty of estimated diffusion length. Two approaches were proposed to improve the measurement accuracy: (1) the thickness effect of each layer in this heterostructure on photocurrent response is asymmetric so that certain thickness combination can be chosen to reduce the uncertainty; (2) on account of the limited accuracy of the optimal thickness determined by photocurrent spectra, estimated diffusion length should be verified by spectrum fitting. Taking these improvements into account, the exciton diffusion length in copper phthalocyanine film is determined as 20 ± 5 nm from curve fitting by this method.

Well-defined hexangularly faced CdS nanorod arrays were fabricated via a facile one-step and nontemplate hydrothermal approach in large scale by using biomolecules of glutathione as capping agents. Structural and morphological evolutions of CdS nanorod arrays were studied by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. A formation mechanism of CdS nanorod arrays via this one-step synthesis was tentatively studied by investigating the effects of synthesis parameters on the nanorod arrays. The growth process of CdS nanorod arrays was discussed further from the absorption spectra of CdS nanorod arrays obtained at different reaction times.

Based on an anodic aluminum oxide template, a sol−gel dip-coating technique and electrophoretic deposition processes were combined to fabricate TiO 2 nanowire arrays, copper phthalocyanine (CuPc) nanowire arrays, and CuPc-coated TiO 2 nanowire (CuPc/TiO 2 NW) arrays. The resulting nanostructures were characterized by field-emission scanning electron microscope, energy dispersive X-ray microanalysis system, X-ray diffraction patterns, and time-resolved fluorescence spectra. A series of dual-layered photoreceptors containing the above three kinds of nanowire arrays as the charge generation layer (CGL) were designed and fabricated. Their photoconductivities under illumination of visible light were investigated using a photoinduced xerographic discharge technique. It was found that the photoreceptor based on CuPc/TiO 2 NW arrays as CGL exhibited 1 order of magnitude higher photoconductivity than that of pristine TiO 2 or CuPc nanowire arrays due to the large donor−acceptor (CuPc-TiO 2) contact area and the di...

Perylene derivatives are an important class of n-type semiconductors. With the exceptions of bay-substituted and N-swallow-tail alkyl/tert-butyl substituted derivatives, most perylene diimides are insoluble. The recently reported perylene tetraesters are highly soluble, but are less electron-deficient. In this paper, a series of perylene monoimide diesters have been synthesized, which have good solubility and acceptable electron-accepting property due to the introducing of imide and ester groups in one perylene molecule. Their electrochemical properties and structural ordering were examined by cyclovoltammetry and X-ray diffraction technique, respectively. Their absorption and emission spectra are reported and discussed.

It has been a challenge to synthesize thiol-functionalized polyacetylenes because of the poisoning effect of mercapto group on the early transition-metal catalysts. Rhodium complexes such as [Rh(cod)Cl]2 can catalyze the polymerizations but the products are insoluble and intractable. In this work, we tackled this challenge. Sulfur-containing polyacetylenes with macroscopic processability were successfully synthesized by separating thiol pendant from polyene backbone with a flexible spacer (in P1), capping free mercapto group with acetyl or alkyl group (in P2 or P3), and using a zwitterionic complex Rh+[η6-C6H5(nbd)B–(C6H5)3] as catalyst. The soluble polymers were characterized by NMR, IR, UV, PL, and TGA analyses. Due to the specific interactions between thiol group and zinc cation, ZnO nanoparticles were chemisorbed onto the surfaces of polymer films, as verified by AFM analysis. Polymer P2 and ZnO nanoparticles could be readily hybridized by simply mixing the two components in an organic solvent such as...

Organic–inorganic hybrid heterojunctions were fabricated from porous silicon (PS) and N,N′-diphenyl-3,4,9,10-perylenetetracarboxylic diimide (DPP). PS was prepared by electrochemical anodization of p-type Si wafers and DPP was embedded into PS by electrodeposition to form DPP/PS composites. Photoluminescence and surface photovoltaic spectra demonstrated a charge transfer process taking place in the composites, resulting in a higher exciton dissociation efficiency for the composites than pristine PS. The exciton dissociation efficiency could also be adjusted by the PS etching time, because the interface area in the composites varied with the PS etching time.

Sub-micron fibers of pure polyaniline (PANI) doped with sulfuric acid or hydrochloric acid were prepared by electrospinning PANI with suitable molecular weight dissolved in hot sulfuric acid. A modified electrospinning setup was employed with a coagulation bath as a collector, where dilute sulfuric acid was used as coagulation bath. The factors influencing the morphology and conductivity of the synthesized PANI fibers were investigated, including the concentration of dilute H 2 SO 4 solution in the coagulation bath, the doped PANI concentration in H 2 SO 4 solution, the type of doping acid and the voltage applied to the solution. The morphologies of doped PANI fibers were characterized by scanning electron microscope (SEM). The structure of the resulting fibers was analyzed by Fourier transform infrared spectroscopy and UV–vis spectrometer. The conductivity of PANI fibers were characterized by I – V characteristics. Homogeneous PANI fibers with a diameter of 370 nm and a high conductivity of 52.9 S/cm were prepared. The possible mechanisms of different morphology formation and conductivity of PANI fibers were also discussed.

This paper focuses on the fabrication of organic-inorganic composite materials with optoelectronic functionality based on carbon nanotubes (CNTs) by chemical and physical modifications. The one-dimensionally (1D) ordered composites of rare earth phthalocyanine compounds (RePc2) encapsulated by MWCNTs were obtained using a simple capillary filling method. The CNT-templated assembly of RePc2 nanowires was performed by a phase-separation method. Two other kinds of organic-inorganic 1D-ordered optoelectronic composites were prepared using the template method: coating MWCNTs with a fluorescent poly(tripheny lamine) related co-polymer can be realized via a facile phase-separation strategy: 1D hy brid of bamboo-shaped CNTs covalently bound to RePc2. The relationship between the microstructure of the obtained 1D-ordered composites and optoelectronic properties was studied, and it was found that these ordered composites exhibited enhanced photoconductivity due to the charge transfer between the composite components.

An easy synthesis of 2,3-di-/1,2,3-trisubstituted indo-l-izines has been developed via a formal [3+2] annulation of α-EWG ketene S, S-acetals with 2-pyridine-/2-quinolinecarbaldehyde. The disubstituted products are formed via an intramolecular aza-Michael- addition and subsequent elimination of acetic acid, followed by desulfenylation- assisted by acetic acid, whereas the trisubstituted products are obtained via a similar conjugate addition followed by elimination of alkanethiol. This strategy has been applied to the synthesis of bis(1-indolizinyl)methanes by the condensation of a 2,3-disubstituted indolizine with aldehydes/ketones in the presence of a catalytic amount of BF 3 ·OEt 2 .

Nanobelts, flower-like and rhizoid-like nanostructures of pure polyaniline (PANI) doped with sulfuric acid or hydrochloric acid were prepared via electrospinning by using a coagulation bath as the collector after optimizing the fabrication parameters. The morphologies of these nanostructures were characterized by scanning electron microscope (SEM). The possible formation mechanisms were discussed.

Size-controllable and vertically oriented TiO2 nanotube arrays were fabricated by using anodic oxidation of pure titanium sheets in electrolyte solutions and were characterized by field-emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). A double-layered photoconductive device (Au/copper phthalocyanine/TiO2 nanotubes/titanium) was designed and fabricated based on the TiO2 nanotube arrays. The I−V curves demonstrated typical heterojunction characteristics and remarkable photoconductive performance for the devices. The effect of the thickness of copper phthalocyanine (CuPc) and the diameter of TiO2 nanotubes on the photoconductive property of devices was studied. The current value increased by 2 or 3 orders of magnitude when exposed to light from the dark, depending on the thickness of the CuPc layer and the diameter of TiO2 nanotubes.

Large-scale three-dimensional (3D) CdS nanocrystals with a flowerlike morphology were synthesized by a facile hydrothermal treatment from Cd(NO3)2, thiourea, and hexamethylenetetramine [(CH2)6N4, HMT], where HMT acted as a capping agent. The reaction conditions influencing the synthesis of these 3D CdS nanocrystals such as initial precursor ratios, reaction time, reaction temperatures, and capping agents were studied and optimized. The morphology, structure, and phase composition of CdS nanostructures were examined by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and high-resolution TEM. The formation mechanism of the 3D CdS nanocrystals with flowerlike structure was proposed based on the results, which may pave the way to shape-controlled synthesis of inorganic nanocrystals with 3D complex structures. The room-temperature photoluminescence (PL) of the obtained CdS nanocrystals was also studied.

A novel organic–inorganic hybrid composite was prepared from poly(9-vinyl carbazole) (PVK) and silicon nanoparticles (NPs). The optical properties of the composites were characterized by photoluminescence (PL), photoluminescence excitation (PLE), and PL decays. The results indicated that an efficient Forster resonance energy transfer (FRET) took place from PVK (donor) to silicon NPs (acceptor), which was necessary for the optimization of polymer/inorganic NPs hybrid light-emitting diodes.

A series of 3,4,9,10-tetra-(n-alkoxy-carbonyl)-perylene (PTAC, n = 4, 6, 8, 10, 12) derivatives with various alkyl chains were synthesized via a simple and efficient phase-transfer catalysis method. It was found that the length of the alkyl chains attached to the perylene skeleton greatly influenced aggregation behaviour. The finding that it was easier for PTAC derivatives with shorter alkyl chains to form crystal films was interpreted in terms of molecular volume and steric repulsion. The photoconductivity of the materials was investigated by xerographic photoinduced discharge technique and the results showed that photosensitivity increased with the decreasing length of the alkyl chain attached to perylene core. This result was consistent with the changing trend of aggregate structure observed for the PTAC derivatives used in this study: the shorter the substituted alkyl chain, the more ordered the film was and, thus, the greater was the photosensitivity.

The molecular aggregation state of a porphyrin-perylenediimide dyad can be changed by treating with trifluoroacetic acid. Transmittance electron microscopy (TEM) images revealed that lamella microstructures were formed when the dyad precipitated from neutral solvent, but spherical nano-particles were obtained when precipitating from acidic solution. X-ray diffraction patterns showed that the lamella microstructures and the nanoparticles were polycrystalline and amorphous solids, respectively. By using rational perylenediimide and porphyrin as reference compounds, careful analyses on the UV-visible spectra of the dyad and the references under different conditions were conducted and the results demonstrated that both the porphyrin and perylendiimide subunits of the dyad took J-aggregation in neutral solvent, but after being treated with trifluoroacetic acid and chloroform solution, the perylenediimide subunit changed to an H-aggregation while the porphyrin subunits changed to a random packing mode.

A functional organic–inorganic composite containing carbazole moieties (electron donors) and TiO2 (electron acceptors) in different molar ratios, TiO2-modified poly(N-vinylcarbazole) (PVK–TiO2), was synthesized through a nucleophilic reaction. The molecular and electronic structure of the PVK–TiO2 composite was characterized with Fourier transform infrared, ultraviolet–visible absorption, cyclic voltammetry, and so forth. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of the PVK–TiO2 composite were higher than those of pristine poly(N-vinylcarbazole). The PVK–TiO2 composite exhibited an enhanced glass-transition temperature and improved thermal stability. The photoinduced charge transfer observed in photofluorescence and photoconductivity measurements makes applications in the field of photodetectors possible. The PVK–TiO2 composite containing carbazole moieties and TiO2 in a molar ratio of about 58 :1 was found to have the best photosensitivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

PbCl2-based thin films of perovskite structure with hole-transporting carbazole derivatives as the organic layer were successfully prepared by spin-coating from dimethylformamide solution containing stoichiometric amounts of organic and inorganic moieties. The crystal structure and optical property of the hybrid perovskite were characterized by Fourier transform infrared (FT-IR) spectrum, X-ray diffraction (XRD), UV–vis absorption and photoluminescence (PL). FT-IR spectra confirmed the formation of organic–inorganic hybrid perovskite structure. UV–vis spectra of hybrid perovskite thin films exhibited a wide absorption band in ultraviolet region as well as a sharp peak at 330 nm characteristic of PbCl2-based layered perovskite. X-ray diffraction profiles indicated that the layered structure was oriented parallel to the silica glass slide plane. Meanwhile, double-layer photoreceptors of the hybrid perovskite were also fabricated, which showed the enhancement of photoconductivity by carbazole chromophore.

This work used micro dispensing technology to fabricate the master of microlens array, then uses electroforming technology to replication the Ni mold insert of microlens array and finally used micro hot embossing to replicate the plastic microlens array. This work used the Si10 resin by AutoStrade Company for dispensing material. The resin material was exposed to 80W halogen light. The resin will be hardened and become convex by surface tension effect on exposition. It can be used as the master of microlens array. This work sputtered a silver layer of 150 nm thick on the master for conducting electricity layer. The electroforming technology replicateed on the Ni mold insert from the master of microlens array. Finally, the micro hot embossing technology was used to replicate the molded microlens array. The molding experiment used PMMA and PC optical film. The experiment studied the influence of processing parameters of hot embossing by processing temperature, embossing pressure, embossing time and de-molding temperature. This work used the Taguchi’s Method to search the best processing parameter for molded microlens array. This work used the microscope, surface profiler and SEM to measure the surface profile of master, mold insert and molded microlens array. This work also used AFM to measure the surface roughness of master, mold insert and molded microlens array. In addition, this work measured the optical strength and the focal length to discuss optical characteristics of molded microlens array.

High porous poly(hydroxyethyl acrylate- co -acrylonitrile) [P(HEA-AN)] membranes were prepared by a phase inversion method. Porous polymer electrolytes are prepared by soaking the porous membranes in the electrolyte solution. The ionic conductivity of the porous polymer electrolytes was found to be as high as 3.66 × 10 −3 S cm −1 . The membrane structure changed with the different processing conditions. With increasing mole ratio of AN in the copolymer, the cross-sectional structure of the membrane changes from finger-like to honeycomb-like and ionic conductivity of porous polymer electrolytes is improved. As the polymer concentration increases, the pore diameter of porous membrane decreases and ionic conductivity of porous polymer electrolyte is improved obviously.

Organic nanograting heterojunctions for photoelectric conversion were studied based on a two-dimensional analytic exciton transport model. The photocurrent and external quantum efficiency were investigated as the function of materials and geometric parameters. It showed that the introduction of the complicated heterointerfaces changed the exciton distribution within the nanostructures and enhanced significantly the exciton dissociation probability. The photoelectric conversion was determined by the cooperation of the two mechanisms of light absorption and exciton migration. The possibility of the nanograting heterojunctions applied to photovoltaic devices was evaluated quantitatively with the recombination-dominated assumption at donor–acceptor interface. The results suggested that the photovoltaic performance in these nanograting heterojunctions might be improved significantly after optimization when compared to that in a planar heterojunction.

Gas-sensing behaviors to chemical vapors of both the polypyrrole and the nano-structured polypyrrole composite film prepared by adding a small amount of carbon nano-tubes (CNTs) to act as nano-fiber seeds were investigated. The experimental results showed that although the gas-sensitivity of the film to trimethylamine was decreased to a certain extent by adding CNTs to form the nano-structure, the resistance of the film to moisture was improved greatly while the rapid response was remained. Moreover, SEM and XRD indicated that the orientation degree of the polypyrrole composite film was improved significantly by the CNTs.

A direct N-trifluoromethylation method has been developed by the use of the in situ generated [ArICF3](+) species as the electrophilic trifluoromethyl source. Upon treatment of N-H ketimines with Ruppert-Prakash reagent in the presence of PhI(OAc)2 and KF, or with Togni's reagent II catalyzed by copper salt, N-trifluoromethylated imine products were obtained in moderate to good yields.

A unique domino reaction of enolizable carbonyl compounds with Me3SiCF2Br to construct α-fluoroenones and α-fluoroenals is described to undergo the in situ formation of difluorocarbene and silyl enol ether, difluorocyclopropanation, desilylation, ring-opening, and defluorination sequence. In this tandem reaction, Me3SiCF2Br acts as not only the difluorocarbene source but also the TMS transfer agent as well as internal bromide and fluoride anion catalyst. It allows the transformations to occur smoothly under only a catalytic amount of n-Bu4NBr as initiator.

A novel domino annulation strategy for the construction of benzo[b]thiophenes is presented which occurs in the presence of Cs2CO3 and Ag2CO3.

A unique domino reaction of enolizable carbonyl compounds with Me3SiCF2Br to construct α-fluoroenones and α-fluoroenals is described to undergo the in situ formation of difluorocarbene and silyl enol ether, difluorocyclopropanation, desilylation, ring-opening, and defluorination sequence. In this tandem reaction, Me3SiCF2Br acts as not only the difluorocarbene source but also the TMS transfer agent as well as internal bromide and fluoride anion catalyst. It allows the transformations to occur smoothly under only a catalytic amount of n-Bu4NBr as initiator.

In order to obtain new materials with synergetic or complementary behaviors, polyaniline composite was prepared by chemical oxide method using zeolite as template. A film over interdigital carbon electrodes was formed via casting approach. Gas sensitivity of the film to trimethylamine was examined at room temperature. The results indicated that, in comparison with the polyaniline film prepared by normal in situ polymerization, not only the morphology of polyaniline composite was clearly different, but also the heat stability of polyaniline film was improved significantly by adding zeolite. Gas sensitivity of the composite film to trimethylamine strongly depended on the type of zeolite added. For the system containing β-zeolite (its specific surface area was 592 m 2 ·g -1 , the size of the channel was 2.27 nm, mole ratio of Si/Al was 60), the gas sensitivity to trimethylamine decreased remarkably compared with that of polyaniline film and for FUYB-zeolite (its specific surface area was 740 m 3 ·g -1 , the size of the channel was 2.46 nm, mole ratio of Si/Al was 12), it was enhanced significantly. All these may be the results of synergetic effects or complementary behaviors between polyaniline and zeolite. This composite film showed excellent gas sensitivity and stability, rapid response to trimethylamine, and good selectivity to analogous gases while being easily recovered with high-purity N 2 to exhibit good reproducibility.

Polythiophene composite film was formed via in situ polymerization at room temperature onto interdigital carbon electrodes immersed into the monomer–oxidant contained mixture by adding a small amount of boron trifluoride etherate. Examinations on the gas sensitivity of polythiophene composite film to a series of vapors were carried out. It was found that the film showed good sensitivity to ammonia, as well as fast response and good reproducibility. Furthermore, the polymer film sensor could be easily recovered by high-purity N 2 .

Under basic conditions, a series of 4,4-dialkylthio-1,2-diaza-1,3-butadienes were synthesized in good to excellent yields via a novel azo-coupling decarboxylation reaction by reacting α-carboxyl ketene dithioacetals with aryldiazonium salts in aqueous medium.

A highly photoresponsive perovskite hybrid containing an electroactive organic component (H1) was fabricated. A disubstituted polyacetylene (PA) with a hidden amino functionality (P3) was synthesized, hydrolysis and quaternization of which afforded the desired PA ammonium salt (P5). Mixing P5 with lead bromide readily yielded H1, which was stable, soluble, and film-forming. The inorganic framework induced the polymer chains to align in an ordered fashion, which helped to populate the chain segments with long conjugation lengths. The hybrid emitted a blue light (457 nm) in a high quantum yield (62%), thanks to the enhanced electronic conjugation, the weakened interaction between the layer-segregated chains, and the efficient energy transfer from the inorganic sheets to the organic layers. P3 exhibited a half-discharge time as short as approximately 0.7 s, representing the first example of an efficient photoconductive disubstituted PA. While stable to normal light illumination, H1 was rapidly bleached upon exposure to high-power UV irradiation, enabling facile generation of two-dimensional luminescent photopatterns. After the UV irradiation, the emissions of P9 and P9/H12 were enhanced and weakened, respectively, proving that the inorganic perovskite framework works as a photocatalyst for accelerating the bleaching process of the conjugated PA chains.

To overcome the problem of film-forming technology, water-soluble polypyrrole was obtained in the process of chemical oxide by adding a small amount of poly (sodium-p-styrenesulfonate). The resulting product PPy/Poly(sodium-p-styrene sulfonat) was coated on the interdigital electrodes of carbon via spin-coating or casting approach, and its gas-sensitivity to trimethylamine at room temperature was investigated. The results indicated that, the technology of film-forming was not only improved greatly, but also this film still showed good gas-sensitivity to trimethylamine of 3.189 × 10−1 mol/m3, its value of gas-sensitivity had reached to 2–3 orders of magnitude within 3 min, had good selectivity to analogy gases, and its resistance to moisture was improved obviously. Otherwise, this film also exhibited good reproducibility and stability, and easily recovered with high-purity N2 at room temperature.

To obtain a nanoscale binder suitable for pigment-based inkjet ink printing on fabrics, a polymer microemulsion with a high content of soft monomer of butyl acrylate (BA) was synthesized via a modified microemulsion polymerization method, where N-methylolacrylamide (NMA) served as the cross-linking monomer and monododecyl maleate (MDM) as the copolymerizable surfactant. The effects of the functional monomers (NMA, MDM), the weight ratios of monomers, and the solid contents on the microemulsion properties were investigated by TEM, DSC, particle size analyzing, and fabric inkjet printing. The results indicated that the microemulsion had a number-average particle diameter less than 50 nm and with narrow particle size distribution. It was also found that the glass transition temperatures (Tg) of the film formed from the microemulsion could be lower than −30 °C. Fabric inkjet printing application of the pigment-based inks formulated with the as-considered optimum microemulsion as a binder and commercial pigment dispersions demonstrated excellent printability of the inks, and good colour fastnesses and softness of the printed fabrics.

In the presence of titanium(IV) chloride, the C-C bond-forming reaction of the α-cyanoketene cyclic dithioacetal 1,3-dithiolan-2-ylideneacetonitrile with various aldehydes and ketones afforded multifunctional pentanedinitriles, 3-substituted- or 3,3-disubstituted 2,4-di-1,3-dithiolan-2-ylidenepentanedinitriles, respectively, in good to excellent yields under very mild conditions. A possible mechanism involving consecutive C-C bond formation was proposed.

Polyaniline composite was prepared with chemical oxide method by adding a small amount of TiO 2 sol–gel. This film on the interdigital electrodes of carbon paste was formed via spin-coating or immersion method with in situ polymerization approach. And its gas-sensitivity to trimethylamine was examined at room temperature. The results indicated that, the heat stability of polyaniline film was improved obviously by adding 10 wt% TiO 2. Meanwhile, this film still showed excellent gas-sensitivity to trimethylamine of 5.14 × 10 −7 mol mL −1 , its value of gas-sensitivity was up to three to five orders of magnitude within 3 min, and had good selectivity to analogy gases. The film also exhibited good reproducibility and stability, and easily recovered with high-purity N 2 at room temperature.

The organic–inorganic hybrid compound (C 8 NH 6 –CH 2 CH 2 NH 3 ) 2 CuCl 4 (AEI–CuCl 4 ) was synthesized from ethanol solution containing copper chloride and 3-2-(aminoethyl) indole hydrochloride (AEI–HCl). High order diffraction peaks corresponding to (0 0 l ; l = 2, 4, 6, …) observed in the X-ray diffraction profile of AEI–CuCl 4 indicated the formation of hybrid crystal with layered perovskite structure. The organic–inorganic hybrid crystal thin film can be easily prepared by spin-coating method from the ethanol solution of the AEI–CuCl 4 perovskite and it showed characteristic absorptions of CuCl-based layered perovskite centered at 288 and 388 nm, as well as the photoluminescence peak at around 420 nm. The unaided-eye-detectable blue fluorescence emission comes from the cooperation of AEI–HCl and AEI–CuCl 4 perovskite, in which protonized aminoethyl indole dominates the shape of the spectrum and the enhancement of emission intensity is due to the formation of the perovskite structure. The thermal analysis presented that the AEI–CuCl 4 perovskite started to melt at 182 °C, together with the beginning of the decomposition of the hybrids. Compared with the organic–inorganic perovskite hybrids reported previously, the AEI–CuCl 4 perovskite shows a novel stepwise decomposition behavior.

Highly ordered spin-coating films of a conjugated molecule, trans -2,3,4,5,6-pentafluorostilbene were fabricated on quartz substrate by making use of the C–F–––H noncovalent intermolecular interaction, whose strength is as high as that of hydrogen bond. The C–F–––H–O interactions are strong enough to drive the molecules in the foundation layer erecting over the substrate and the C–F–––H–C interactions between adjacent molecules maintain such a molecular orientation in the subsequent layers. X-diffraction patterns and polarized raman spectral data confirmed the ordered structure in the spin-coating films.

AlGaAs/GaAs multi-quantum well (MQW) was prepared by molecular beam epitaxy(MBE) with growth-interrupted heterointerface (GIH) method and continuous growth (CG) method, respectively. The microstructures of the MQWs were characterized by double-crystal X-ray rocking curve (DCRC) and atomic force microscopy (AFM), and the photoluminescence (PL) properties of the MQWs were also studied. The MQWs grown with GIH method show that higher order satellite peaks of Pendellosung fringes are observed in DCRC, the roughness of surface is much reduced in AFM, and the full width at half maximum (FWHM) of exciton line is much narrower in PL. The results indicate that the GIH method reduces the monolayer growth step density at the heterointerface due to the migration of surface atoms for a few minutes growth interruption, and substantially improves the quality of AlGaAs/GaAs MQWs.

Gas sensors based on the Fe 2 O 3 –ZnO nanocomposites with different compositions of Fe:Zn was prepared by a sol–gel and spin-coating method. Morphology of the Fe 2 O 3 –ZnO nanocomposites was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD, D/max-rA) and energy dispersive X-ray analysis (EDX). The results of electrical and sensing measurement indicated that the sensor with Fe:Zn = 2% exhibited fairly excellent sensitivity and selectivity to NH 3 at room temperature. The response and recovery time of the sensor were both less than 20 s. Finally, the mechanism for the improvement in the gas sensing properties was discussed.

Comparative tests were carried out on the gas-sensing properties of the evaporation films of zinc tetraphenylporphyrin and its fluorinated derivative [zinc- meso -tetra (2,3,4,5,6-pentafluorophenyl)-porphyrin] to some volatiles (ammonia, trimethylamine, triethylamine, methanol, ethanol, and formaldehyde) at room temperature. Experimental results indicated that the gas responses and the response rates of the films strongly depended upon the species of volatiles and the fluorination modification. Although the fluorination affected the response to trimethylamine slightly, the response magnitude and speed to ammonia increased dramatically after the fluorination. The response magnitude could increase by four orders of magnitude within 1 min, and the response speed was enhanced by more than 30 folds. On the contrary, the responses to triethylamine, ethanol, methanol, and formaldehyde decreased. Moreover, the fluorinated films showed good reversibility even at room temperature by the purge with highly pure N 2 .