可溶性钒氧酞菁在不同介质中的吸收光谱研究

研究了四丙基取代钒氧酞菁（Ｐｒ４ＶＯＰｃ）在不同介质中的吸收光谱。Ｐｒ４ＶＯＰｃ分子在不同介质中的吸收光谱差别很大：在稀溶液中以分子的单体吸收为主（λｍａｘ＝７０７ｎｍ），在浓溶液和ＰＭＭＡ薄膜中由于形成平行排列结构的二聚体而使分子单体的吸收峰发生蓝移（λｍａｘ＝６６０ｎｍ），在蒸发膜中则由于形成斜交结构的二聚体使得分子单体的吸收峰发生分裂形成红移和蓝移峰（λｍａｘ＝７２０ｎｍ，６６０ｎｍ），在溶液沉积的固态薄膜中由于形成结晶相Ｉ而表现出强烈的近红外吸收（λｍａｘ＝８２６．９ｎｍ）。造成这种差别的原因是四个丙基的引入加大了ＶＯＰｃ分子的空间位阻效应。通过热处理或溶剂蒸汽处理，可以使Ｐｒ４ＶＯＰｃ蒸发膜转变成具有强近红外吸收的结晶相Ｉ；而只有通过溶剂蒸汽处理才能使ＰＭＭＡ介质中的Ｐｒ４ＶＯＰｃ转变成结晶相ＩＩ。     

偶氮基染料掺杂薄膜的双光子图象存储

研究了偶氮基染料掺杂薄膜ＭＯ－ＰＶＡ和ＥＯ－ＰＶＡ的双光子存储特性。在对薄膜用Ａｒ＾＋激光作预激发下实现了Ｈｅ－Ｎｅ激光的红光存储。获得了实时和短时存储照片。光电记录存储曲线，分析了双光四能级系统的存储机制。实现确定了最佳预激发功率约为０．２８Ｗ／ｃｍ＾２，最小Ｈｅ－Ｎｅ光可存储功率密度低于０．２Ｗ／ｃｍ＾２。     

掺杂聚合物蓝光发光二极管

报道了用有机染料ＴＰＢ（１，ｌ，４，４－四苯基丁二烯）分散到ＰＶＫ（聚乙烯基咔唑）中的掺杂聚合物作有源层制作的蓝光发光二极管及其发光特性。聚合物发光层用旋转涂敷的方法制备，用透明导电材料ＩＴＯ（铟锡氧化物）、金属Ａｌ作为正负电极。器件正向偏压为１３Ｖ时，可以看到蓝光发射，峰值波长为４５５ｎｍ，注入电流为５０ｍＡ／ｃｍ２时，亮度为４４ｃｄ／ｍ２。     

常态下Pr掺杂Y—Ba—Cu—O薄膜的激光响应研究

本文对倾斜基片上生长的ＹＢａＣｕＯ薄膜在不同膜厚和多种浓度Ｐｒ掺杂条件下的激光响应进行了研究．这种现象的根源是薄膜层状结构造成的热电系数张量各向异性．与未掺杂ＹＢａＣｕＯ薄膜的激光响应相比，掺Ｐｒ使薄膜的激光响应幅度显著提高，并且仍具有较好的能量线性响应和时间响应．掺Ｐｒ２０％，效应最明显；掺Ｐｒ５０％时，效应则显著降低．本文认为，由于Ｐｒ掺杂使ＣｕＯ面载流子浓度降低从而显著增强声子曳引作用是导致ＹＢａＣｕＯ薄膜ＣｕＯ面热电系数增大及其激光响应幅度提高的主要原因     

Spiro－Oxaziue染料掺杂高分子材料光致变色效应的研究

报道Ｓｐｉｒｏ－Ｏｘａｚｉｕｅ染料掺杂高分子（ＳＯ／ＰＶＡ）膜具有很强的可逆光致变色效应，通过对这种高分子膜吸收光谱的测试，证实ＳＯ分子具有二个特征吸收带，一个在３６０ｎｍ，另一个在５９５ｎｍ，分别对应于二个分子异构体ＳＯ１和ＳＯ２，有关这种ＳＯ／ＰＶＡ光致变色过程的研究给出了ＳＯ１对紫外光和ＳＯ２对可见光（波长在５１５ｎｍ）的吸收系数分别为１．２ｃｍ２／Ｊ和６×１０－２ｃｍ２／Ｊ，ＳＯ２的寿命为３８ｓ。最后本文给出了采用这种ＳＯ／ＰＶＡ膜实现紫外－可见光图像转换和空间光调制操作的实验演示结果     

钒氧酞菁多晶薄膜的稳态光电压特性研究

报道了Ａｌ／ＶＯＰｃ／ＩＴＯ夹心结构在稳态连续光照射下的光电压作用谱，稳态光电压作用谱不仅依赖于照射光的波长，而且依赖于ＶＯＰｃ（钒氧酞菁）多晶薄膜的堆积方式，对ＶＯＰｃ在相１，相１１，及α型三种堆积方式的稳态电压波长响应进行了研究，并对其内在机制作了初步探讨。     

借助于PrBa2Cu3O7的红外光谱讨论Pr在体系中的价态

本报道了陶瓷和薄膜ＰｒＢａ２Ｃｕ３Ｏ７材料的红外和远红外反射谱，从陶恣和薄膜样品的声子谱的比较中萃取ＰｒＢａ２Ｃｕ３Ｏ７材料沿着ｃ轴振动的Ｂｌｕ模分别位于１１０，１５８，１９４，２０２，３９５，５８０ｃｍ＾－１，ＰｒＢａ２Ｃｕ３）７和ＹＢＣ３Ｏ７－δ有类似的晶体结构，分析和比较这两种材料的声子谱，尤其是沿着ｃ轴振动的Ｂｌｕ模，我们认为Ｐｒ的Ｂｌｕ模位于１９４ｃｍ＾－１，并由此而建议从红外测试结果     

四磺化酞菁钴在水溶液中二聚作用力的研究

采用发光光度法研究了四磺化酞菁钴（ＣｏＴＳＰｃ）在水、醇－水（ＭｅＯＨ、ＥｔＯＨ、ＰｒＯＨ）、胶束、微乳液、乙二胺、氨水、氰化钾的水溶液中的二聚现象，测定了ＣｏＴＳＰｃ的二聚常数ＫＤｏＴＳＰｃ与ｅｎ、ＮＨ３、ＣＮ形成配合物的稳定常数Ｋ和生成反应速率常数ｋ。     

偶氮染料掺杂的聚甲基丙烯酸甲酯薄膜的热光性质研究

本文演示了用阿贝折射仪测定染料掺杂聚合物薄膜热光系数的方法;通过改变掺杂体含量的方法,方便地实现了聚合物体系的折射率控制;通过热光系数的测量,计算了聚合物薄膜的热膨胀系数,并用以解释了聚合物薄膜的热光系数随掺杂体含量增加先增大后减小的实验观察.     

二氧化碳从它溶胀后的聚合物中的解吸

研究了经过４０℃,８．０￣１４．０ＭＰａ的超临界二氧化碳溶胀后的６种聚合物ＬＤＰＥ、ＰＰ、ＰＡ６、ＥＶＡ、ＰＵ中的ＣＯ２解吸情况,模拟了聚合物中ＣＯ２的解吸规律,即以时间的自然指数递减规律,并根据Ｆｉｃｋ扩散定理从理论上推导出ＣＯ２在聚合物中的解吸方程,由解吸方程计算解吸扩散系数,结果表明ＣＯ２的解吸扩散系数数量级达１０＾－７ｃｍ＾２／ｓ,解吸扩散系数与ＣＯ２在聚合物中的浓度和温度以及解吸前聚合物     

Optical and non-linear optical properties of vanadium oxide phthalocyanine films

The optical and non-linear optical properties of peripheral-substituted vanadium oxide phthalocyanine (VOPc) film and substituted VOPc/polymer composite film were investigated using stationary and transient spectroscopy techniques. The absorption Q band of the VOPc/polymer composite film shows a red shift relative to that of the peripheral-substituted VOPc film, revealing the monomeric characteristics of VOPc molecules. Effective quenching of PL emission was observed for the VOPc/polymer composite film and could be assigned to the efficient VOPc–polymer interaction. From pump-probe and optical Kerr effect (OKE) measurements, two decay components were obtained by fitting the transients for both VOPc films. The fast component, in a femtosecond time domain, originates from the electron–phonon interaction, and the difference in their slow decay is an indication of an efficient ISC process in the VOPc/polymer composite film. The third-order non-linear optical susceptibilities of these films were determined to be in the order of 10^-11 esu. Received: 25 October 2001 / Revised version: 8 January 2002 / Published online: 7 February 2002     

Thin-film growth behavior of non-planar vanadium oxide phthalocyanine

The thin film properties of organic semiconductors are very important to the device performance. Herein, non-planar vanadyl phthalocyanine(VOPc) thin films grown on rigid substrates of indium tin oxide, silicon dioxide, and flexible substrate of kapton by organic molecular beam deposition under vacuum conditions are systematically studied via atomic force microscopy and x-ray diffraction. The results clearly reveal that the morphology and grain size are strongly dependent on the substrate temperature during the process of film deposition. Meanwhile, the VOPc films with the structure of phase I or phase II can be modulated via in situ annealing and post-annealing temperature. Furthermore, the crystalline structure and molecular orientation of vapor-deposited VOPc can be controlled using molecular template layer 3, 4, 9, 10-perylenetetracarboxylic dianhydride(PTCDA), the VOPc film of which exhibits the phase I structure. The deep understanding of growth mechanism of non-planar VOPc film provides valuable information for controlling structure-property relationship and accelerates the application in electronic and optoelectronic devices.     

Experimental investigations on plasticized PMMA/PVA polymer blend electrolytes

Blend based polymer electrolytes composed of poly (methyl methacrylate) (PMMA), poly(vinylalcohol) (PVA) and LiClO₄ are prepared using solvent casting technique. The polymer films are characterized by XRD and FTIR studies to determine the molecular environment for the conducting ions. These polymer films have been investigated in terms of ionic conductivity using the results of impedance studies. The influence of the blend composition on the electrochemical behaviour is also discussed. The highest room temperature conductivity obtained for the film consisting of PMMA, PVA, LiClO₄ and DMP is 0.06×10⁻³ S/cm at 303 K. The PMMA-PVA blend based polymer electrolytes look very desirable and promising for lithium battery applications.     

Energy harvesting of PZT/PMMA composite flexible films

Polymer/lead zirconate titanate {[Pb(Zr_x, Ti_1-x)O₃], PZT, x = 0.40} flexible composite films are prepared by solvent evaporation technique. Carbon tape used as a top and bottom electrodes for fabricating flexible PZT composite films. The phase purity and functional groups of PZT and polymer humps are confirmed by XRD and FTIR respectively. XPS analysis showed that PMMA contains carbon (C) and oxygen (O). Carbon (C), oxygen (O), lead (Pb), zirconium (Zr) and titanium (Ti) are present in PZT/PMMA composite films. The chemical states of Pb, Zr and Ti ions are 2⁺, 4⁺ and 4⁺ respectively confirmed by XPS. The higher forefinger bending motion of the film is found to reveal greater output voltage (5.2 V) than the output voltage (1.6 V) for slight bending motion of the forefinger. Therefore, based on the results human mechanical forces induce compressive stress on PZTs ferroelectric based composite films and are excellent candidate for energy harvester.     

Microhardness Studies of the Interphase Boundary in Rubber‐Softened Glassy Polymer Blends Prepared with/without Compatibilizer

Abstract

The interphase boundary of incompatible polymer blends such as poly(methyl methacrylate) (PMMA)/natural rubber (NR) and polystyrene (PS)/NR, and of compatible blends such as PMMA/NR/epoxidized NR (ENR) and PS/NR/styrene–butadiene–styrene (SBS) block copolymer, where ENR and SBS were used as compatibilizers, was studied by means of microindentation hardness (H) and microscopy. Cast films of neat PMMA and PS, and blended films of PMMA/NR, PS/NR, PMMA/NR/ENR, and PS/NR/SBS were prepared by the solution method using a common solvent (toluene). Hardness values of 178 and 173 MPa were obtained on the surfaces of the neat PMMA and PS, respectively. After the inclusion of soft phases, the binary (incompatible) and the ternary (compatible) blend surfaces show markedly lower H‐values. Scanning electron and optical microscopy reveal a clear difference at the phase boundary of the surface of compatible (smooth boundary) and incompatible (sharp boundary) blends. The compatibilized blends were characterized by using microhardness measurements, as having the thinnest phase boundary (～30 µm), while incompatible blends were shown to present a boundary of about 60 µm. The hardness values indicate that the compatibilizer is smoothly distributed across the interface between the two blend components. Results highlight that the microindentation technique, in combination with microscopic observations, is a sensitive tool for studying the breadth and quality of the interphase boundary in non‐ or compatibilized polymer blends and other inhomogeneous materials.     

Fabrication of segmented nanofibers by template wetting of multilayered alternating polymer thin films

Segmented polystyrene (PS) and poly-methyl methacrylate (PMMA) nanofibers were fabricated by wetting nanoporous alumina templates with multilayered polymer thin films. The order and thickness of the polymers within the thin films affected the resulting nanofiber morphology, PS and PMMA segment properties, and created unique core-shell structure in the PMMA segments. The core-shell structure suggests a complex wetting phenomenon. Fabrication of polymer nanostructures by wetting of layered thin films opens the arena of multifunctional, one-dimensional, polymer nanostructures with segments having individual and specific functionalities.     

掺杂浓度与溶剂对偶氮聚合物薄膜全光开关

用重复旋转涂膜法制备了乙基红(ER)偶氮染料与聚甲基丙烯酸甲酯(PMMA)掺杂聚合物薄膜和乙基橙(EO)与聚乙烯醇(PVA)掺杂聚合物薄膜.测量了两种聚合物薄膜样品全光开关特性,比较分析了薄膜样品的掺杂浓度和溶剂对全光开关效应的影响,实验结果表明:增加掺杂浓度和溶剂,极性薄膜样品的全光开关效应增强且开关的本底信号增大,但对开关的响应速度影响很小;选择合适的掺杂浓度和强极性溶剂,在室温和几个mW的弱功率控制光条件下聚合物薄膜具有毫秒级开关响应时间和40%以上的开关调制深度,最大的调制深度达72%以上.     

Fluorescence and Time-Resolved Delayed Luminescence of Porphyrins in Organic Solvents and Polymer Matrices

Porphyrin dyes fulfill an essential function in photosynthesis and are important in photodynamic therapy and in a range of electronic devices. Their spectroscopic characteristics may play a crucial role in these processes. The spectral properties of two porphyrin dyes: tetraphenylporphyrin and tetraphenysulfporphyrin in organic solvents (acetone, chloroform, methyl alcohol, and dimethyl-sulfoxide) and in polyvinyl alcohol and poly(methylmethacrylate) films have been investigated. Absorption, fluorescence, and microsecond time-resolved delayed luminescence spectra have been measured at room temperature. The existence of different aggregated dye forms in the ground and excited states has been demonstrated. The manifold of dye species depends on the solvent/polymer. In the case of the polymers, it also depends on the solvent used to coat the polymer film. Delayed luminescence spectra and decay times of the two porphyrins in the different solutions and in polymeric matrices suggest that different mechanisms of deexcitation of the singlet excited states may be responsible for their generation in these and other porphyrin dyes.     

Hierarchic Structure Formation in Binary and Ternary Polymer Blends

The phase morphology of multi-component polymer blends is governed by the interfacial interactions of its components. We discuss here the domain morphology in thin films of model binary and ternary polymer blends containing polystyrene, poly(methyl metacrylate), and poly(2-vinylpyridine) (PS, PMMA, PVP). When sandwiched between two non-polar surfaces, characteristic lateral phase morphologies are observed after the film formation by spin-coating. We discuss here two techniques, by which hierarchical lateral structures in polymer films can be made. The first method makes use of two simultaneously occurring interfacial instabilities. The second technique employs the effect of a variation of the enthalpic interaction parameters in a ternary polymer mixture on its lateral polymer phase morphology.