含对苯二甲酸双(对甲氧基苯)酯液晶基元聚噻吩的合成

从设计合成单体噻吩取代对苯二甲酸双(对甲氧基苯)酯入手,以FeCl3为催化剂,CHCl3为溶剂,合成了一种新型以聚噻吩为共轭主链的共轭聚合物.利用核磁共振(1H-NMR),红外光谱(IR)等方法表征了单体和聚合物的结构.利用差示扫描量热仪(DSC)、带热台的偏光显微镜(POM)、紫外光谱(UV)和荧光光谱(PL)研究了聚合物液晶性和光学性能.结果表明,该聚合物为无规聚合物.通过偏光显微镜观察,单体具有向列型液晶态纹影织构,而由于大体积刚性侧基破坏了聚合物的液晶性,聚合物分解温度之前未观察到该聚合物有明显的双折射现象.     

高分子金属络合物的性能及应用进展

介绍了高分子金属络合物的种类、合成 ,主要综述了高分子金属络合物不同于低分子络合物的催化性能、电学性能、光学性能及磁性以及作为催化剂、光学材料、电学材料等方面的应用进展     

Enhancing the performance of an electrochromic device by template synthesis of the active layers

This work describes the use of template synthesis to produce materials with optimized properties to be used in electrochromic devices. A composite prepared by the inclusion of polyaniline within the pores of a cellulose acetate was used as primary electrochromic layer and a porous V_{2 5} phase was used as an auxiliary electrode to counter balance the charge in the entire device. The device closed with a gel polymer electrolyte exhibited a very high optical contrast (light yellow to dark blue) with ΔT_{750 nm}=78%. However, the optical response time indicates a slow ion exchange during electrochromic cycles. By comparing the voltammogram and the curve obtained by differentiation of the absorbance variation with time, it was possible to identify the contribution of each redox couple to the total color change.     

Direct‐Write Formation and Dissolution of Silver Nanofilaments in Ionic Liquid‐Polymer Electrolyte Composites

Materials with reconfigurable optical properties are candidates for applications such as optical cloaking and wearable sensors. One approach to fabricate these materials is to use external fields to form and dissolve nanoscale conductive channels in well‐defined locations within a polymer. In this study, conductive atomic force microscopy is used to electrochemically form and dissolve nanoscale conductive filaments at spatially distinct points in a polyethylene glycol diacrylate (PEGDA)‐based electrolyte blended with varying amounts of ionic liquid (IL) and silver salt. The fastest filament formation and dissolution times are detected in a PEGDA/IL composite that has the largest modulus (several GPa) and the highest polymer crystal fraction. This is unexpected because filament formation and dissolution events are controlled by ion transport, which is typically faster within amorphous regions where polymer mobility is high. Filament kinetics in primarily amorphous and crystalline regions are measured, and two different mechanisms are observed. The formation time distributions show a power‐law dependence in the crystalline regions, attributable to hopping‐based ion transport, while amorphous regions show a normal distribution. The results indicate that the timescale of filament formation/dissolution is determined by local structure, and suggest that structure could be used to tune the optical properties of the film.     

Coating nanodiamonds with biocompatible shells for applications in biology and medicine

Use of nanodiamonds (NDs) as nontoxic nanoparticles for biological imaging, sensing, and drug delivery is expanding rapidly. The interest in NDs is triggered by their unique combination of optical properties. ND can accommodate nitrogen-vacancy color centers which provide stable fluorescence without photobleaching or photoblinking and their electronic structure is very sensitive to magnetic and electric fields. The limited options to control ND properties during synthesis or by direct surface functionalization leave room to be improved upon by employing surface coatings engineered precisely for a particular application. The major disadvantages of unmodified NDs are their limited colloidal stability and tendency to non-specifically adsorb biomolecules. This review aims to summarize recent advances in coating NDs (namely with silica and polymer shells), which addresses these disadvantages and enables the use of NDs in biological applications such as targeting of specific cells, drug delivery, and biological imaging.     

Metal‐Polymer Nanocomposites for Functional Applications

Nanocomposites combine favorable features of the constituents on the nanoscale to obtain new functionalities. The present paper is concerned with the preparation of polymer‐based nanocomposites consisting of metal nanoparticles in a polymer matrix and the resulting functional properties. Emphasis is placed on vapor phase deposition which inter alia allows the incorporation of alloy clusters with well defined composition and tailored filling factor profiles. Examples discussed here include optical composites with tuned particle surface plasmon resonances for plasmonic applications, magnetic high frequency materials with cut‐off frequencies well above 1 GHz, sensors that are based on the dramatic change in the electronic properties near the percolation threshold, and antibacterial coatings which benefit from the large effective surface of nanoparticles and the increased chemical potential which both strongly enhance ion release.     

含硝基噁二唑聚炔的合成及三阶非线性光学性能

设计合成了一种含硝基噁二唑功能基的聚炔材料。通过红外光谱(IR)和核磁共振(1H-NMR)对该聚炔化合物进行了结构表征。利用紫外光谱(UV-vis)和热重分析(TGA)对其性能进行了评价。TGA显示其热稳定性相对于单体有很大提高,UV-vis表明它在500 nm以上长波区吸收很弱。该聚炔化合物的非线性光学性能借助Z-scan技术进行研究,其χ(3)达3.25×10-11(esu)。与含烷基的同类聚炔比较,拉电子基团硝基有效地提高了含噁二唑聚炔的三阶非线性光学性能。     

Influence of ion-pairing and chemical enhancers on the transdermal delivery of meloxicam

Purpose: To investigate the influence of ion pairing and chemical enhancers on the transdermal delivery of meloxicam. Method: We examined the increased permeation of meloxicam produced by ion pair formation with six organic bases, diethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, and N-(2′-hydroxyethanol)-piperidine, and four normal permeation enhancers, oleic acid, menthol, azone, and N-methyl-2-pyrrolidone. The cumulative permeation was markedly increased in the presence of either a counter ion or chemical enhancers. In particular, we proved the formation of a meloxicam/amine ion-pair in solution by ¹³C-NMR (nuclear magnetic resonance). Results and conclusion: The cumulative permeation was markedly increased in the presence of either a counter ion or chemical enhancers. These results suggest that the degree of enhancement possibly depends on the structure and hydrophilicity of the counter ions.     

聚合物光限幅材料的研究

随着现代激光技术和武器的快速发展,急需激光防护材料(光限幅材料)和设备来防护人眼和光学传感设备免受激光的破坏.由于高分子光限幅材料具有大的非线性光学性能、快速的光学响应、高的损伤阈值和好的加工性能引起人们的广泛兴趣. 在这篇论文中,从分子结构以及分子结构对光限幅性能和光限幅机制的影响,对高分子光限幅材料进行了详细的综述,并提出高分子光限幅材料未来的发展方向.     

发光稀土高分子研究进展及应用

目的 探究稀土高分子光学性能的研究情况,开发其应用潜力,从发光机理、制备、应用3个方面综述稀土高分子的研究进展,给后续的研究提供参考。方法 经过大量文献的搜集、翻阅,对发光稀土高分子的研究进展进行整理及总结。结果 稀土高分子的发光机理以中心稀土离子发光、天线效应和共荧光效应为主,按成键与否将其分为掺杂型稀土高分子和键合型稀土高分子,主要应用于农用塑料薄膜、防伪油墨、夜光纤维、荧光探针、太阳能电池等领域。结论 稀土高分子具有良好的综合性能,目前已应用于多个领域,深入研究稀土高分子的光学性能具有必要的科研意义和价值。     

离子注入技术改性聚合物薄膜的研究进展

离子注入技术改性聚合物薄膜在电子及电器工程中有着巨大的潜在应用价值。综述了近年来聚合物薄膜经离子注入后在导电性能、光学性能、导磁性能及表面力学机械性能等方面的最新进展。分析了注入离子与聚合物相互作用的物理过程,并指出了该领域存在的问题及发展方向。     

Zero-field optical manipulation of magnetic ions in semiconductors

Controlling and monitoring individual spins is desirable for building spin-based devices, as well as implementing quantum information processing schemes. As with trapped ions in cold gases, magnetic ions trapped on a semiconductor lattice have uniform properties and relatively long spin lifetimes. Furthermore, diluted magnetic moments in semiconductors can be strongly coupled to the surrounding host, permitting optical or electrical spin manipulation. Here we describe the zero-field optical manipulation of a few hundred manganese ions in a single gallium arsenide quantum well. Optically created mobile electron spins dynamically generate an energy splitting of the ion spins and enable magnetic moment orientation solely by changing either photon helicity or energy. These polarized manganese spins precess in a transverse field, enabling measurements of the spin lifetimes. As the magnetic ion concentration is reduced and the manganese spin lifetime increases, coherent optical control and readout of single manganese spins in gallium arsenide should be possible.     

Swift heavy ion irradiation effect on Cu-doped CdS nanocrystals embedded in PMMA

Semiconductor nanocrystals (NCs) have received much interest for their optical and electronic properties. When these NCs dispersed in polymer matrix, brightness of the light emission is enhanced due to their quantum dot size. The CdCuS NCs have been synthesized by chemical route method and then dispersed in PMMA matrix. These nanocomposite polymer films were irradiated by swift heavy ion (SHI) (100 MeV, Si⁺⁷ ions beam) at different fluences of 1 × 10¹⁰ and 1 × 10¹² ions/cm² and then compared their structural and optical properties by XRD, atomic force microscopy, photoluminescence, and UV-Vis spectroscopy before and after irradiation. The XRD spectra showed a broad hump around 2θ ≈ 11·83° due to amorphous PMMA and other peaks corresponding to hexagonal structure of CdS nanocrystals in PMMA matrix. The photoluminescence spectra shows a broad peak at 530 nm corresponding to green emission due to Cu impurities in CdS. The UV-Vis measurement showed red shift in optical absorption and bandgap changed from 4·38–3·60 eV as the irradiation fluency increased with respect to pristine CdCuS nanocomposite polymer film.     

Ho-Ion-Polymer/Graphene Heterojunctions Toward Room-Temperature Ferromagnets

Organic ferromagnetic materials offer great promise for spintronic devices, carbon-based chips, and quantum communications, but remain as a challenging issue due to their low saturation magnetization and/or unsustainable ferromagnetic properties. To date, magnetic ion polymers have displayed paramagnetism without exception at room-temperature. In this study, it is reported for the first time that, owing to the structural restriction and charge exchange of Ho ion by polymer/graphene π–π stacking heterojunctions, holmium ion polymer composites exhibited typical hysteresis lines of ferromagnetic materials at room temperature. The room-temperature ferromagnetic ion polymer composite presented the highest saturation magnetization value of 3.36 emu g⁻¹ and unprecedented sustainable ferromagnetism, compared to reported room-temperature organic ferromagnetic materials. Accordingly, prepared ferromagnetic composites also achieved impressive wave absorption properties, with a maximum reflection loss of as much as −57.32 dB and a broad absorption bandwidth of 5.05 GHz. These findings may promote the development of room-temperature organic ferromagnetic materials.     

Ion bombardment of Poly-Allyl-Diglycol-Carbonate (CR-39)

Ion bombardment is thought to have great potential for improving the optical properties of polymeric materials. In this paper, Poly-Allyl-Diglycol-Carbonate (CR-39) polymer samples were bombarded with 320 keV Ar and 130 keV He ions, at different ion fluences. Effects of ion bombardment on the optical properties of CR-39 have been investigated using UV-vis spectrophotometer and photoluminescence (PL) spectroscopy. UV-vis spectra of irradiated samples reveal that the optical band gap decreases with increasing the ion fluence for both Ar and He ions. The width of the tail of localized states in the band gap (E_u) was evaluated using the Urbach edge method. The decrease in the PL intensity with the increase in the ion fluence was observed. This decrease is attributed to ion bombardment induced defects and clusters in the CR-39 which serves as non-radiative centers.     

Monolithic integrated four DFB lasers array with a polymer-based combiner for WDM applications

Compact and low cost integrated photonic components will be of significant importance for a wider penetration of optical technologies into private customer access systems. Hybrid semiconductor/polymer integrated technologies are very promising to achieve this goal by virtue of the highly flexible nature of polymers at both molecular and material scale, of their compatibility with processing steps used in semiconductor technologies, and of their reasonably low cost. One example is an integrated semiconductor 4-wavelength laser array with a polymer based 1–4 passive optical combiner on the same substrate. The polymer waveguide structure is a polysulfone material stripe embedded in PMMA cladding layers, and the laser structure is a buried ridge stripe (BRS). The optical coupling between the active and passive elements is a butt-joint coupling via a reactive ion beam etched (RIBE) semiconductor mirror facet. Such a photonic integration simplifies the optical coupling between a laser array and single mode fibers, while reducing the packaging cost. This optical device has been achieved with interesting performances such as small dimension size (1.2 × 0.5 mm), low laser threshold current, and output powers for each laser from the polymeric waveguide port of at least 1.5 mW without additional on-chip optical amplification.     

Effect of cycling on the magnetization of ion exchanged magnetic nanocomposite based on polystyrene

Magnetic nanocomposites containing iron oxide particles embedded in a polymer matrix have been synthesized using the method of ion exchange. They have been characterized by using low temperature and room temperature magnetic measurements and Mössbauer spectroscopy. The iron content in these samples has also been determined. The results have been analysed and explained. The physical and chemical properties of these nanocomposite materials are different from those of the bulk. Some of the unique properties of these materials find application in information storage, color imaging, ferrofluids and magnetic refrigeration.     

Evolution of the structure and magneto-optical properties of ion beam synthesized iron nanoclusters

Changes in the structural, magnetic, and optical properties are observed during the synthesis of metallic nanoclusters fabricated on the surface of a thin silica layer by ion beam implantation of iron atoms. Iron atoms were implanted to the fluence of 10¹⁶ cm⁻². The ion implantation depth in 400-nm thick SiO₂ film on a Si (100) substrate was 25 nm. The implanted samples were subsequently annealed for periods of seconds to hours at 1000 °C with Electron Beam Annealing. Ellipsometry and Rutherford Backscattering Spectrometry spectra were fitted with appropriate models to retrieve the optical characteristics, composition, and structure of the samples. Magneto Optical Kerr Effect measurements and SQUID magnetometry were performed to investigate the effect of the structural changes identified by TEM measurements on the superparamagnetic and magneto-optical properties of the samples during the annealing process. The changes in the Fe crystalline(core)/amorphous oxide(shell) structure and the position of the nanoclusters relative to the surface observed for small annealing durations are shown to enhance the Kerr effect resulting into high coercive field and high amplitude in the Kerr rotation and ellipticity.     

Preparation and characterization of iron phthalocyanine polymer magnetic materials

A novel kind of polymer magnetic material iron phthalocyanine (FePc) was prepared via the polymerization of phthalonitrile with iron pentacarbonyl. The pre-polymerization was monitored by FTIR and UV–Vis spectra. Microwave dielectric properties of prepolymers were dependent on their chemical structures. The thermal properties of FePc polymer were evaluated by TGA, the initial decomposition temperature of completely cured polymer was about 420 °C and char yield at 800 °C was 63.56%. Controlling the pre-polymerization degree of phthalonitrile by the reaction time, the magnetic properties of cured polymer materials can be finely tuned. The saturation magnetization of cured polymer decreased from 2.48 to 0.42 emu/g, whereas the coercive force increased from 123.8 to 228.6 Oe. The microstructure of iron phthalocyanine polymer was characterized by scanning electron microscope and the typical layer structure morphology of phthalocyanine polymer was clearly observed.     

Effects of different sintering atmosphere on the structure and properties of Cu-doped ZnO powders prepared by sol–gel method

Cu-doped ZnO powders have been successfully synthesized by the sol–gel method in different sintering atmospheres, including argon and air, respectively. The effects of the sintering atmosphere on the structure, magnetic and optical properties of Cu-doped ZnO were investigated in detail by X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, vibrating sample magnetometer and photoluminescence measurements. The results showed that the Cu-doped ZnO powders sintered in Ar had a hexagonal wurtzite structure without any secondary phase, however, CuO was observed in the sample sintered in air. From the magnetic and photoluminescence spectra, it could be seen that the sintering atmospheres strongly influenced the magnetic and optical properties of the powders.