Nonaggregated Zinc Phthalocyanine in Mesoporous Nanocrystalline TiO2 Thin Films

Summary: A simple sonochemical approach has been successfully developed to deposit poorly dissolved phthalocyanine dyes onto the surface of a highly‐ordered mesoporous nanostructured TiO₂ thin film. The aggregation‐free phthalocyanines are effectively encapsulated and stabilized in the nanopore arrays of the zeolite‐like mesoporous nanocrystalline TiO₂ thin film. Highly dispersed dye∥TiO₂ heterojunction arrays with a large contact area can be obtained by using this interesting approach.

The incorporation of phthalocyanine dyes into the surface of a highly‐ordered mesoporous nanostructured TiO₂ thin film, a potential photocatalyst.     

纳米TiO2介孔薄膜的模板组装制备研究

以TiCl₄为无机前驱体、三嵌段高分子共聚物EO₂₀PO₇₀EO₂₀为模板剂，在非水条件下制备了有序的锐钛矿TiO₂纳米晶介孔薄膜。通过热重-差热（TG-DTA）分析、X射线衍射（XRD）分析、原子力显微观察（AFM）及N₂吸附-脱附等测试对样品进行了表征。结果表明，薄膜具有均一的大介孔孔径（～10 nm），其BET比表面积为150 m²·g^-1，薄膜较宽的无机壁厚显著提高了介孔结构的热稳定性。通过红外（IR）光谱分析考察了溶胶-凝胶过程中发生的物理化学变化。在对薄膜表面形貌进行AFM观察的基础上初步探讨了嵌段共聚物EO₂₀PO₇₀EO₂₀对薄膜孔结构形成的导向机理。     

Pattern Formation in Thin Polymer Films Containing Conducting Polyaniline

Summary: In the present work knowledge the authors tried to direct the phase separation process in a thin polymer composite film to manufacture a polymer pattern via self organisation of the blend components. The Au substrate was modified by applying with a PDMS stamp a pattern of alternating stripes of a self-assembled monolayer. This in turn influenced the microstructure of the blend, allowing for the production of elongated domains repeating the pattern of the substrate. The blends studied in this work contained conducting polyaniline doped with camphorsulfonic acid or diphenyl phosphate and polystyrene. The role of the dopant was to induce electrical conductivity in polyaniline as well as to improve its solubility in common organic solvents. The microstructure of thin films was analysed using atomic force microscopy (AFM), dynamic secondary ion mass spectroscopy (dSIMS) and optical microscopy.     

Europium‐Doped Mesoporous Titania Thin Films: Rare‐Earth Locations and Emission Fluctuations under Illumination

Herein, Eu^III‐doped 3D mesoscopically ordered arrays of mesoporous and nanocrystalline titania are prepared and studied. The rare‐earth‐doped titania thin films—synthesized via evaporation‐induced self‐assembly (EISA)—are characterized by using environmental ellipsoporosimetry, electronic microscopy (i.e. high‐resolution scanning electron microscopy, HR‐SEM, and transmission electron microscopy, HR‐TEM), X‐ray diffraction, and luminescence spectroscopy. Structural characterizations show that high europium‐ion loadings can be incorporated into the titanium‐dioxide walls without destroying the mesoporous arrangement. The luminescence properties of Eu^III are investigated by using steady‐state and time‐resolved spectroscopy via excitation of the Eu^III ions through the titania host. Using Eu^III luminescence as a probe, the europium‐ion sites can be addressed with at least two different environments within the mesoporous framework, namely, a nanocrystalline environment and a glasslike one. Emission fluctuations (⁵D₀→⁷F₂) are observed upon continuous UV excitation in the host matrix. These fluctuations are attributed to charge trapping and appear to be strongly dependent on the amount of europium and the level of crystallinity.     

Functionality of Aerosol-Gel Deposited TiO2 Thin Films Processed at Low Temperature

TiO₂ thin films have been deposited using the Aerosol-gel process and heat-treated at low temperature. Functional coatings necessitate reasonably good abrasion resistance in order to support possible damages related to a targeted application. Besides, specific applications of TiO₂ films require additional criteria, e.g. a tailored refractive index, a controlled chemical composition or a suitable crystallization degree. In this paper, we present several low temperature preparation procedures that answer the different criteria and allow to envisage applications on thermally sensitive substrates.     

氧化锡和氧化锌双层薄膜的XPS研究

用XPS法研究了SnO2 /ZnO及ZnO/SnO2 双层膜中锌和锡的扩散情况 ,结果表明 :锌在SnO2中的扩散比锡在ZnO中的扩散更容易。讨论了锌在SnO2 层中的扩散方式和扩散的结果。在ZnO层留下了较多的氧 ,并使部分的SnO2 还原为SnO。     

Mesoporous Titania Thin Film with Highly Ordered and Fully Accessible Vertical Pores and Crystalline Walls

We report the preparation of mesoporous titania thin films with the R m pore structure derived from the Im m self‐assembled ordering of the titania species and an EO₁₀₆PO₇₀EO₁₀₆ triblock copolymer. The films were spin‐cast and then aged at 18 °C at a relative humidity of 70 %, which led to the orientation of the Im m structure with the [111] direction perpendicular to the substrates. The [111] body‐diagonal channels became vertical channels upon calcination at 400 °C, thus leading to thin films with vertical channels. The pores are ordered over a large area of up to 1 μm². The titania films can be formed on various types of substrates. By using a titania film formed on a Pt‐coated Si wafer as a template, we produced by an electrochemical‐deposition technique arrays of gold nanowires, whose morphology suggests that most of the pores of the titania thin films are accessible. The pore structure of vertical channels is stable up to 600 °C, at which temperature the wall materials crystallize into anatase.     

Gold Nanoparticles Supported on Mesoporous Titania Thin Films with High Loading as a CO Oxidation Catalyst

In the present work, 2.4 nm gold nanoparticles (Au NPs) are uniformly dispersed on mesoporous titania thin films which are structurally tuned by controlling the calcination temperature. The gold content of the catalyst is as high as 27.8 wt %. To our knowledge, such a high loading of Au NPs with good dispersity has not been reported until now. Furthermore, the reaction rate of the gold particles is enhanced by one order of magnitude when supported on mesoporous titania compared to non‐porous titania. This significant improvement can be explained by an increase in the diffusivity of the substrate due to the presence of mesopores, the resistance to agglomeration, and improved oxygen activation.     

新型LB成膜材料—两亲性侧链取代酞菁锌的合成

本文合成了一种新型的两亲性硬脂酸侧链取代的酞菁化合物。利用LB膜技术制备了致菁化合物与正十六烷混合的单层和多层LB膜,LB膜内酞菁分子大环与基片大体平行,表明该分子具有良好的成膜性能。     

Preparation and Characterization of Titania Thin Films from Aqueous Solutions

Dip- or spin-coating and characterization of titania (TiO₂) thin films from various aqueous solutions have been studied. The aqueous titanium solutions mainly used in this study were halogen- and chelate-free solutions with the concentrations up to 1.4 M derived from titanium isopropoxide (TIP) with tetramethylammonium hydroxide (TMAOH) or some alkylamines, while aqueous and alcoholic solutions containing titanium atoms stabilized chelating ligands were examined for comparison. The TiO₂ films prepared from the TIP-TMAOH solution were already crystallized at 350°C to anatase form and those formed at 600°C had high transparency and refractive indices of 2.40. No carbon residue in the film prepared at 400°C was detected by XPS. The pure anatase form was sustained up to 850°C. Interestingly, it was found that the (004) preferentially oriented anatase films were obtained from TIP-lactic acid (LA) system until 700°C. The solutions containing citric acid (CA) or alkanolamines yielded anatase and rutile form fired at the temperatures equal to or higher than 600°C. Carbon residue was detected in the film fired at 400°C. The film thickness monotonically decreased from the upper to the bottom ends of the substrate. However, it was found that the thickness uniformity was drastically improved by an addition of sucrose to the aqueous solutions. The effects of the solution composition and polyhydroxy compounds on the crystal modifications of formed films and the film uniformity are discussed.     

Synthesis and Thin Film Phase Behaviour of Functional Rod‐Coil Block Copolymers Based on Poly(para‐phenylenevinylene) and Poly(lactic acid)

We report the synthesis of a series of block copolymers consisting of a rod‐like semiconducting poly(2,5‐di(2′‐ethylhexyloxy)‐1,4‐phenylenevinylene) (DEH‐PPV) block and a flexible poly(lactic acid) (PLA) block that can be selectively degraded under mild conditions. Such selectively degradable block copolymers are designed as self‐assembling templates for bulk heterojunction donor–acceptor layers in organic solar cells. A lamellar microphase‐separated domain structure was identified for block copolymers with PLA volume fractions between 29 and 79% in bulk and thin films using SAXS, TEM, and AFM. Depending on the ratio of the two blocks we find either lamellae oriented parallel or perpendicular to the substrate in thin films.

     

Third-order Nonlinear Optical Properties of Octa-substituted Metal-free Phthalocyanine Thin Films

Third-order nonlinear optical susceptibility, χ⁽³⁾ of symmetrically octa-substituted metal-free phthalocyanine thin films measured by the third-harmonic generation technique are reported. The metal-free phthalocyanine has been found to show a χ⁽³⁾ (−3ω; ω,ω, ω) value as large as 7.73×10⁻¹² esu at 1.80 μm. The figure of merit, χ⁽³⁾/α, was estimated to be 4.17×10¹⁷ esu cm at 1.05 μm and 6.97×10¹⁶ esu cm at 1.65 μm. Both linear and third-order optical properties of liquid-crystalline metal-free phthalocyanines are discussed     

Thin Films of Photoactive Polymer Blends

Photoactive polymer blends: Films consisting of two photoactive homopolymers, MEH‐PPV and P3HT, are prepared via spin coating. Investigation of the lateral domain distance inside the blended film, performed by using grazing incidence small angle X‐ray scattering techniques, shows that the theoretically predicted blending ratio seems most promising (see figure).

     

酞菁锂薄膜的光电流极性研究

利用旋转涂膜法和真空镀膜法制备了以酞菁锂薄膜为工作层的有机光电器件, 结构为氧化铟锡/聚二氧乙基噻吩: 聚对苯乙烯磺酸/酞菁锂/聚偏氟乙稀/铝(ITO/PEDOT: PSS/LiPc/PVDF/Al). 在可见光和近红外脉冲激光照射下, 研究了器件的光电流极性. 在532 nm脉冲激光照射下, 器件的外电路光电流方向从ITO流向铝; 但在1064 nm脉冲激光照射下, 其外电路光电流极性发生反向, 即从铝流向ITO. 酞菁锂薄膜的吸收光谱和X射线衍射谱图显示, 其对可见和近红外光有非常广的吸收, 且为x晶型. 酞菁锂自由基的双极性特性可随入射光波长的变化而改变.     

Poly(3,4-ethylenedioxythiophen)/Poly(4-styrenesul-fonate): Thin Films and Microfibers

This Feature Article describes our recent researches on processing poly(3,4-ethylenedioxythiophene /poly(4-styrenesulfonate) (PEDOT/PSS) colloidal dispersion into thin films which exhibit high conductivity and high transparency, and into microfibers which exhibit high conductivity and high mechanical strength. The state-of-the-art thin films and microfibers are expected to utilize to sophisticated touch screens and wearable electronic devices as organic transparent electrodes and woven electric circuits, respectively.     

Controlled Nanopores in Thin Films of Nonstoichiometrically Supramolecularly Assembled Graft Copolymers

Herein, nanometer‐scale morphologies of graft‐copolymer‐like supramolecular thin films, composed of sulfonic acid terminated polystyrene (SPS) and poly(2‐vinylpyridine) (P2VP), and their application to antireflection coatings were investigated. The intermolecular complexes of SPS and P2VP, formed through nonstoichiometric multiple hydrogen bonding between the sulfonic acid group of SPS and the nitrogen atom in pyridine unit of P2VP, occurring in film deposition allowed for the formation of spherical micelles (with SPS and P2VP as the corona and core, respectively) in the thin film. Interestingly, the domain size of the micelles was tunable from approximately 20 to 90 nm on average by controlling either the blend ratio of components or the concentration of polymer solution. Furthermore, nanoporous thin films could be easily prepared by removing the core of micelle‐based nanostructures by using a simple solvent etching process, leaving sulfonic acid groups on the surface of nanopores, which can be utilized as potential functional sites. Those resultant nanoporous thin films were conveniently employed as an antireflection layer on a glass substrate, giving a maximum 97.8 % transmittance in the visible wavelength range.     

Increasing the Open‐Circuit Voltage in High‐Performance Organic Photovoltaic Devices through Conformational Twisting of an Indacenodithiophene‐Based Conjugated Polymer

A fused ladder indacenodithiophene (IDT)‐based donor–acceptor (D–A)‐type alternating conjugated polymer, PIDTHT‐BT, presenting n‐hexylthiophene conjugated side chains is prepared. By extending the degree of intramolecular repulsion through the conjugated side chain moieties, an energy level for the highest occupied molecular orbital (HOMO) of –5.46 eV – a value approximately 0.27 eV lower than that of its counterpart PIDTDT‐BT – is obtained, subsequently providing a fabricated solar cell with a high open‐circuit voltage of approximately 0.947 V. The hole mobility (determined using the space charge‐limited current model) in a blend film containing 20 wt% PIDTHT‐BT) and 80 wt% [6,6]‐phenyl‐C₇₁ butyric acid methyl ester (PC₇₁BM) is 2.2 × 10^–9 m² V^–1 s^–1, which is within the range of reasonable values for applications in organic photovoltaics. The power conversion efficiency is 4.5% under simulated solar illumination (AM 1.5G, 100 mW cm^–2).

     

酞菁铜掺杂SnO2超微粒子复合膜的研究

在三－（２，４－二特戊基苯氧基）－一－（８－喹啉氧基）酞菁铜中掺杂ＳｎＯ２超微粒子复合成膜，发现ＳｎＯ２与酞菁铜分子之间有一定的相互作用，对酞菁铜分子的结构有一定的破坏；气敏性研究表明掺杂后导电率提高一个数量级，稳定性提高。     

Controlling Orientation and Functionalization in Thin Films of Block Copolymers

Functionalizing and controlling nanostructures resulting from block copolymer self‐assembly are key factors in defining their application. In this work, a simple but quite general route to achieve both goals simultaneously is discussed. In thin films of polystyrene‐block‐poly(vinyl pyridine) (PS‐b‐PVP) with small concentrations of a gold salt, the salt is found to complex with the PVP block which leads to an orientation of the microdomains normal to the surface after solvent annealing together with functionalization. By increasing the amount of gold salt, on the other hand, micelles are found to form in solutions leading to a range of different morphologies in the thin films.

     

Initiated Chemical Vapor Deposition and Light‐Responsive Cross‐Linking of Poly(vinyl cinnamate) Thin Films

The first vapor‐phase deposition of poly(vinyl cinnamate) (PVCin) is reported. Initiated chemical vapor deposition (iCVD) is used to synthesize PVCin thin films with an average thickness of 100 nm. Free radical polymerization and cyclization reactions compete during the deposition process, with approximately 45% of the repeat units undergoing cyclization. Exposure to UV light (λ = 254 nm) induces dimerization (cross‐linking) of the PVCin, which is quantified using spectroscopic techniques. Approximately 90% of the free cinnamate moieties are dimerized at a UV dose of 300 mJ cm⁻². PVCin is also incorporated into a copolymer with N‐isopropylacrylamide, which exhibits a characteristic change in hydrophilicity with temperature. The copolymer is selectively cross‐linked through a mask, and reversible swelling of patterns with 30 μm resolution is demonstrated by submerging the film in water.