超支化偶氮大分子重氮盐静电层-层自组装膜的制备及光响应性研究

利用超支化偶氮大分子重氮盐作为聚阳离子,与聚阴离子PSSA进行静电层-层自组装,通过紫外光谱、椭偏仪和原子力显微镜等对体系自组装过程及自组装膜的表面形貌进行了表征.在线偏振488nmAr+激光的作用下,自组装多层膜可产生明显的光致二向色性,其取向有序度约为0.02.在干涉的Ar+激光作用下,多层膜表面可形成规则的表面起伏光栅结构.     

含偶氮生色团的“倒浮萍”聚合物LB膜及其可逆光信息存储特性

含偶氮苯功能基团的聚合物在光电子器件研制中具有诱人的应用前景．Wendorff[1]利用偶氮液晶聚合物首次实现可逆的光学信息存储后，利用偶氮苯分子的激光诱导二向色性和双折射效应实现可逆光学信息存储引起人们极大的兴趣．与传统的利用偶氮苯的顺反异构体实现信息存储的方式相比，这种信息存储方式由于偶氯苯分子始终处于热力学稳定的反式构象，因而具有突出的长期稳定性，具有更广阔的应用前景[1,2]．本工作设计合成了以含有给受体的偶氮苯分子为接枝侧链的两亲性聚合物，并研究了其成膜特性与可逆光信息存储特性．1实验部分两亲性聚合物…     

木质素基偶氮聚合物胶体球的制备

利用造纸废液中的碱木素(AL)合成了木质素基偶氮聚合物(AL-azo-COOEt), 并研究其自组装胶体化过程. 木质素偶氮聚合物的成功合成通过核磁共振氢谱(¹H NMR)、紫外-可见(UV-Vis)光谱、傅里叶变换红外(FTIR)光谱和元素分析等表征方法得到证实. 激光光散射(LLS)监测了AL-azo-COOEt的胶体化过程, 自组装形成的胶体球利用透射电镜(TEM)、扫描电镜(SEM)、X射线光电子能谱仪(XPS)和元素分析等进行表征. 结果表明,木质素偶氮聚合物通过疏水聚集作用可以形成规整的实心胶体球, 且为内部较疏水外部较亲水性质的结构. 木质素偶氮聚合物胶体球可以包载疏水性药物阿霉素(DOX), 且其缓释性能可以通过缓冲溶液的pH值来调控.     

Cyclodextrin Polymer Films Optical Waveguide Sensor for Volatile Organic Gas Detection

A sensitive optical waveguide(OWG) sensor which can be used to detect volatile organic compounds(VOCs) was presented. The sensing device(element) was fabricated by means of the immobilization of polyvinyl pyrrolidone(PVP)-cyclodextrin(CD) composite film over a single-mode potassium ion exchanged glass OWG via spin-coating method. The sensor shows higher response to styrene gas than to other VOCs and displays a linear response to styrene gas in a range of 1-1000 μL/L.     

Synthesis of crosslinkable fluorinated polyesters for optical waveguide devices

A series of novel crosslinkable, highly fluorinated polyesters were synthesized by copolycondensation reactions of terephthaloyl chloride with 4, 4′‐(hexafluoroisopropy‐lidene)‐diphenol and 2,2,3,3,4,4,5,5,6,6,7,7‐dodecafluoro‐octane‐1,8‐diol, followed by reaction with 2‐hydroxyethyl methacrylate. The resulting polyesters with the molecular weights (M_n: 12,100–20,000 g mol^?1) and polydispersities (1.49–2.25) were useful for the fabrication of polymer optical devices because of their good solubility in common organic solvent and the processable flexibility. The ratios of the components of the polyesters were characterized by FTIR and NMR. The polyesters had high glass transition temperature (T_g,: up to 170 °C) and good thermal stabilities (T_d: up to 470 °C). The refractive index of the polyester film was tuned and controlled in the range of 1.447–1.576 at 1550 nm by monitoring the component fractions during the preparation procedures. Low‐loss optical waveguides were fabricated from the resulting polyesters and the propagation loss of the channel waveguides was measured to be around 0.56 dB/cm at 1550 nm. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5923–5931, 2007     

Reactive Polymer Based Colloids for Biomedical Applications

Summary: This short review aimed to give to the reader brief applications of polymer colloids in biomedical area and principally in medical diagnostics. Colloidal polymer particles are mainly used as solid supports, as label for biomolecules reactions detection, and as a carrier. The elaboration of appropriate colloids is reached via numerous processes such as polymerization in dispersed media (dispersion, emulsion, precipitation, miniemulsion polymerizations) or as physico-chemical methodologies (i.e., self-assembly). After a short introduction, some particles elaborations are presented and their applications are briefly described and illustrated.     

Planar Integrated Optical Waveguide Sensor for Isopropyl Alcohol in Aqueous Media

An attenuated total reflection (ATR) sensor for water-miscible organic solvents was constructed using a combination of sol-gel processing and integrated optical waveguide (IOW) technologies. The sensor consisted of single-mode, sol-gel based planar waveguide coated with a 40 nm thick, porous sol-gel indicator layer prepared from methyltriethoxysilane and doped with methyl red. The response of the senor to aqueous isopropyl alcohol (IPA) was investigated. Solvation of the indicator dye by IPA causes the absorbance spectrum to undergo a blue shift coupled with an increase in molar absorptivity. IPA was detected by measuring changes in ATR of the guided mode at 488 nm. A response curve extending from 1 to 100% (v/v) IPA in water was constructed for the sensor, from which a detection limit of 0.7% (v/v) IPA/water was estimated. Response and reversal times were typically less than one minute, making this sensor potentially attractive for on-line monitoring applications. The rapid response characteristics are attributable to relatively weak, reversible interactions between the indicator and analyte.     

Novel Photosensitive Fluorinated Poly(arylene ether) Having Zero Birefringence

Summary: A novel photosensitive fluorinated poly(arylene ether) containing chalcone units was synthesized from decafluorinated chalcone and fluorinated bisphenol at low temperature. Upon UV irradiation, the refractive indices of the polymer film were decreased because of the reduction of electronic polarizability in the chalocone moiety. The decrease was more significant in the in‐plane direction than in the out‐of‐plane direction, and consequently, zero birefringence (at 632.8 nm) was obtained after 90 s of exposure.

The changes in the refractive indices and the birefringence of chalcone‐containing fluorinated poly(arylene ether) films synthesized and measured at 632.8 nm with respect to UV irradiation time.     

Plasmon Waveguide Resonance: Principles,Applications and Historical Perspectives on Instrument Development

Plasmon waveguide resonance (PWR) is a variant of surface plasmon resonance (SPR) that was invented about two decades ago at the University of Arizona. In addition to the characterization of the kinetics and affinity of molecular interactions, PWR possesses several advantages relative to SPR, namely, the ability to monitor both mass and structural changes. PWR allows anisotropy information to be obtained and is ideal for the investigation of molecular interactions occurring in anisotropic-oriented thin films. In this review, we will revisit main PWR applications, aiming at characterizing molecular interactions occurring (1) at lipid membranes deposited in the sensor and (2) in chemically modified sensors. Among the most widely used applications is the investigation of G-protein coupled receptor (GPCR) ligand activation and the study of the lipid environment’s impact on this process. Pioneering PWR studies on GPCRs were carried out thanks to the strong and effective collaboration between two laboratories in the University of Arizona leaded by Dr. Gordon Tollin and Dr. Victor J. Hruby. This review provides an overview of the main applications of PWR and provides a historical perspective on the development of instruments since the first prototype and continuous technological improvements to ongoing and future developments, aiming at broadening the information obtained and expanding the application portfolio.     

Viscosity and refractive index adjustment of poly(methyl methacrylate‐co‐ethyleneglycol dimethacrylate) for application in microoptics

Polymer optical components like waveguides or lenses are gaining more and importance as passive or active devices enabling the formation of a sensor and detector platform, e.g. for monitoring the health of large area functional surfaces, which are difficult to access like the wings of an off‐shore wind energy plant. With respect to low‐loss waveguiding and the use of chemical and mechanical stable polymers there is a need to tailor the optical as well as the thermomechanical properties. The given approach describes the addition of electron‐rich small organic molecules like phenanthrene to a poly(methyl methacrylate)‐based polymer matrix enabling a significant refractive index increase from 1.49 up to almost 1.55 (@589 nm). As undesirable side effects the optical transmittance in the visible range at higher guest molecule content is reduced, and a pronounced plasticizing occurs. Both hamper the application of the mixture, e.g. as optical waveguide material. The plasticizing and the accompanied drop of the glass transition temperature, determining the maximum operation temperature, can be partially compensated by the copolymerization of the methyl methacrylate monomer (MMA) with the difunctional monomer ethyleneglycol dimethacrylate (EGDMA) at certain crosslinker content. The resulting new developed guest–host mixtures enable the realization of optical devices with adjusted rheological behavior prior to curing and tailored optical properties after polymerization. Copyright © 2015 John Wiley & Sons, Ltd.     

一种作为锂离子电池负极材料的不含溶剂分子的镉配位聚合物

为了开发高能量密度的锂离子电池(LIB),作为LIB电极材料的配位聚合物,已经受到了研究人员的关注。利用CdCl₂、咪唑(Im)和四氟对苯二甲酸(H₂tfbdc)作用合成了一维配位聚合物[Cd (tfbdc)(Im)₄](Cd-TBI),并利用X射线单晶衍射、红外光谱、元素分析和热重实验对Cd-TBI进行了表征。首次考察了它作为LIB负极材料的电化学性能。在电流密度50 mA·g^-1下循环50次后,Cd-TBI电极提供了154 mAh·g^-1的放电比容量,其容量保持率和库仑效率分别为95.7%和99.2%,展示了优良的循环稳定性。在电流密度1 A·g^-1时,Cd-TBI电极仍保持97 mAh·g^-1的可逆比容量。     

Azobenzene Liquid‐Crystalline Polymer for Optical Switching of Grating Waveguide Couplers with a Flat Surface

Grating waveguide couplers with a flat surface were fabricated in an azobenzene liquid‐crystalline polymer film by holographic lithography using Ar⁺ laser beams at 488 nm. When a probe beam at 633 nm was incident to one grating of a grating waveguide coupler, the beam propagated in the waveguide and an output beam came out from the other grating with the throughput coupling efficiency of ≈5%. Upon irradiation of the film between two gratings with UV light to cause trans–cis photoisomerization of the azobenzene moiety, the intensity of the output beam was repeatedly switched. It was found that the alternating irradiation at 366 and 436 nm induced reversible changes in the intensity of the guided probe beam.

     

Polymeric Membranes Containing Phosphorus in the Chain for Solid Polymer Electrolytes

Abstract

Two new series of solid polymer electrolytes (SPEs) based on phosphorus containing (co)polyesters (PPE) and Lithium triflate were obtained. PPEs are composed of phosphonate moeties (cyclohexyldichlorophosphonate (CHDP)) as linking agent and two diols: PEG (6000) and poly(tetramethylene glycol) (PTMG) in PPE I, and PEG (6000) and 4,4′-cyclohexylidenebisphenol (bisphenol Z, BZ) in PPE II. Polycondensation was carried out in solution in the presence of triethylamine (TEA) as scavenger of HCl side product (PPE I–IIa) and in the absence of any acid acceptor (PPE I–IIb). The Limiting Oxygen Index (LOI) and thermal analysis were performed both on polymers and membranes. The ionic conductivity of SPE membranes based on PPE-salt complexes, with various salt concentrations, was investigated at different temperature and ionic transference numbers were determined. Optimum composition was obtained for the polymer which contains in structure only alkyl units and 15% Lithium triflate.     

Photoactive Poly(aryl ether)s Containing Azobenzene Moieties on Pendants for Fabrication of Thermal Stable Surface Relief Gratings

A series of azobenzene functionalized poly(aryl ether) copolymers(azo-PAEs) containing azo moieties on pendants was prepared by direct copolymerization. The amount of azobenzene chromophores could be controlled by the feed ratio of azo-monomer. Their chemical structures and properties were characterized by means of infrared(IR) spectrometry, UV-Vis, hydrogen nuclear magnetic resonance(¹H NMR), difference scanning calorimetry(DSC), and thermogravimetric analysis(TGA). The results suggest that azo-PAEs had high glass transition temperatures(T_gs) and good thermal stability. By exposing their spin-coated films to an interference pattern laser beam, azo-PAEs could be used for the fabrication of thermal stable surface relief gratings(SRGs).     

Integrated circuit thermal analysis: A new thermal technique for polymer characterization

Polymer characterization has largely helped in the development of thermal analyzers and calorimeters, based mainly on the thermocouple technology, or more recently the semiconductor technology. With the use of an integrated silicon thermopile as a detector, a new thermal technique is appearing, to give more possibilities of investigations in the field of polymeric materials. Combining high sensitivity and use of small amount of sample, the originality of the new design comes from its low power consumption, giving rise to a portable version of the instrument. With such a concept, the thermal analysis technique is carried on the industrial site, to perform online measurements.Melting and crystallization, glass transition, control of reticulation are a promising field of applications for the characterization of polymeric materials on industrial sites.This revised version was published online in November 2005 with corrections to the Cover Date.     

Current Advances towards 4-Hydroxybutyrate Containing Polyhydroxyalkanoates Production for Biomedical Applications

Polyhydroxyalkanoates (PHA) are polyesters having high promise in biomedical applications. Among different types of PHA, poly-4-hydroxybutyrate (P4HB) is the only polymer that has received FDA approval for medical applications. However, most PHA producing microorganisms lack the ability to synthesize P4HB or PHA comprising 4-hydroxybutyrate (4HB) monomer due to their absence of a 4HB monomer supplying pathway. Thus, most microorganisms require supplementation of 4HB precursors to synthesize 4HB polymers. However, usage of 4HB precursors incurs additional production cost. Therefore, researchers have adopted strategies to reduce the cost, such as utilizing low-cost substrate as well as constructing 4HB monomer supplying pathways in microorganisms. We herein summarize the biomedical applications of P4HB, the natural producers of 4HB polymer, and the various strategies that have been applied in producing 4HB polymers in non-4HB producing microorganisms. It is expected that the readers would gain a vivid idea on the different strategic developments in the field of 4HB polymer production.     

Imprinted Polymer Particles for Aluminum Uptake: Synthesis and Analytical Applications

This work reports the preparation of molecularly imprinted polymer (MIP) particles for selective extraction and determination of aluminum ion from aqueous media. Polymerization was achieved in a glass tube containing AlCl₃, morin, 4-vinylpyridine, ethyleneglycoldimethacrylate, 2,2′ - azobisisobutyronitrile. The polymer block obtained was ground and sieved (55–75 μ m) and the Al (III)-morin complex was removed from polymer particles by leaching with 2 M of HCl, which leaves a cavity in the polymer particles. The polymer particles, both prior to and after leaching, have been characterized by IR and differential scanning calorimetry (DSC) studies. The effect of different parameters, such as pH, adsorption and desorption time, type and least amount of eluent for elution of complex from polymer were evaluated. Extraction efficiencies more than 99% were obtained by elution of the polymers with 15 mL of methanol-acetonitrile mixture (1:2) followed by ICP-OES. The limit of detection of the proposed method was 3.5 μ g L^?1. A dynamic linear range (DLR) in the range of 20 to 200 μ g L^?1 was obtained. The relative standard deviation (RSD) was less than 6.5%. The influence of various cationic and anionic interferences on percent recovery of complex was studied. The method was applied to the recovery and determination of aluminum in different real samples.     

Supramolecular Peptide/Polymer Hybrid Hydrogels for Biomedical Applications

Peptides and polymers are the “elite” building blocks in hydrogel fabrication where the typical approach consists of coupling specific peptide sequences (cell adhesive and/or enzymatically cleavable) to polymer chains aiming to obtain controlled cell responses (adhesion, migration, differentiation). However, the use of polymers and peptides as structural components for fabricating supramolecular hydrogels is less well established. Here, the literature on the design of peptide/polymer systems for self‐assembly into hybrid hydrogels, as either peptide‐polymer conjugates or combining both components individually, is reviewed. The properties (stiffness, mesh structure, responsiveness, and biocompatibility) of the hydrogels are then discussed from the viewpoint of their potential biomedical applications.     

Effects of Chemical Stirring Time on the Physical Properties for LiNbO3 Photonic Film Using of Optical Waveguide Applications

Lithium niobate (LiNbO₃) structures are deposited on N-type silicon substrate by chemical sol-gel method. The chemical mixture was prepared with different time of stirrer (8 h, 24 h, 48 h) respectively. The nanostructures are deposited by spin coating at 3000 rpm for 30 sec and annealed 400 °C. They are characterized and analyzed by means of x-ray diffraction and Atomic Force Microscopy. The measurement results show that at increasing of mixing time, the photonic film start to crystallize to become a more regular, homogeneous distribution and Improving, which helps to use in the preparing of optical waveguide and the other of the Photonic and optoelectronics applications.     

The Experimental Study of Acrylamide Based Photopolymer Recording Materials for Applications in Optical Holography

Summary: The photopolymer recording material based on acrylamide monomer has been experimentally studied. After illumination with an interference field, the photopolymerization process is initiated and a diffraction grating is formed in real-time. The performance of the material depends on its chemical composition and recording parameters. Due to its self-developing characteristics, the real-time measurement of hologram formation is used for detection of the recording process. From the measurement, properties of the material can be determined and optimized for different holographic applications.