首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 11 毫秒
1.
光致变色高分子合成研究进展   总被引:1,自引:0,他引:1  
综述了6类光致变色高分子(包括聚甲亚胺型、含硫卡巴腙结构型、含偶氮苯型、含含螺结构型、含二芳基乙烯型、苯氧基萘并萘醌型)的研究状况.讨论了光致变色聚合物的合成方法、变色性质、影响聚合物性质的因素,并对光致变色高分子的未来研究重点和方向进行展望.  相似文献   

2.
朱彩艳  马慧敏  张强  张田林 《化工进展》2014,33(11):3013-3020,3074
阐述了不饱和羧酸类(甲基丙烯酸、丙烯酸和乙烯基苯甲酸)、芳香杂环类(吡啶类、咪唑类和喹啉类)、水杨醛类希夫碱以及Salen配体等功能单体的性能、优点、用途等方面的研究进展,以及基于上述单体制备的离子印迹聚合物吸附特性和应用性能等,展望了离子印迹聚合物功能单体未来的发展方向:一是功能单体种类需要进一步丰富;二是其所具有的性能和功能等还有待于完善。其中,季铵盐化5-氯甲基水杨醛类希夫碱功能单体具有强亲水性能和多官能团特性,对其进行性能研究将会是探索此类功能单体在应用方面的热点内容之一。  相似文献   

3.
Organic photovoltaic cells made with semiconducting polymers remain one of the most promising technologies for low-cost solar energy due to their compatibility with roll-to-roll printing techniques. The development of new light-absorbing polymers has driven tremendous advances in the power conversion efficiency of these devices. In particular, the use of alternating electron rich (donor) and electron poor (acceptor) segments along the polymer backbone can produce low optical bandgap materials that capture more of the solar spectrum. As a result, power conversion efficiencies over 10% are increasingly common for this technology. This review summarizes the recent advances in donor-acceptor polymer design and synthesis, highlighting the structural features that are key to providing high efficiency, scalable and stable devices.  相似文献   

4.
A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review.  相似文献   

5.
星形聚合物的研究与应用进展   总被引:6,自引:0,他引:6  
回顾了结构性能独特且应用颇为广泛的非线性星形聚合物研究现状;介绍了星形聚合物的特点、应用,以及通过活性聚合制备星形聚合物的不同合成方法,比较了各种合成方法的优缺点;综述了星形聚合物用作研究聚合物的支化模型、简化树形聚合物复杂的支化结构、获得聚合物支化信息的研究进展。  相似文献   

6.
Electrochromic polymers are attractive materials with enormous potential in the rapidly developing area of plastic electronics due to their flexibility, low-power consumption, ease of processing and low processing cost. Electrochromic devices created with electrochromic polymers are likely to be alternatives or supplements to the conventional inorganic electrochromic devices, which face challenges of durability and electrochromic properties. Several novel electrochromic polyimides, polyamides, and polynorbornenes prepared via polycondensation, ring-opening metathesis polymerisation (ROMP), etc., are introduced in this article. These various polymer species exhibit high thermal stability and mechanical strength.  相似文献   

7.
Heavy metal removal from water is a great concern for environmentalists and engineers. Ion-imprinted membranes are among the state of the art technologies for selective adsorption of heavy metals from aqueous environment. Dialysis permeation of nickel ions through Ni(II)-imprinted membranes has been thermodynamically studied in our prior work. In current study, the diffusive transport model was developed and then applied for better insight into the retardation mechanisms involved in the ion-imprinted membrane transport. The Sips isotherm model was coupled with the transport model to obtain the governing equation. Chemisorption and physical interactions(bulk diffusion and pore-clogging) were the most probable retardation mechanisms according to the modeling results. Relative retardation factor(η) was also defined as; transport-rate controlled by chemical adsorption to that controlled by physical interactions. With the help of the retardation factor, it was understood that the membrane behavior gradually changes from chemisorption to facilitated transport during permeation time. Effect of important operating parameters such as time, temperature and concentration on transport behavior was also investigated. Results indicated that chemisorption rate is rather higher at lower concentrations, early permeation times and reduced temperatures. In addition, η tabulated greater values for Ni(II) compared to Co(II) due to the imprinting effect.  相似文献   

8.
Polyampholyte polymer systems are composed of varying mixtures of charged monomer subunits. These polymeric systems have gained increasing attention because it is possible to design the final material properties through careful selection of the charged monomer subunits and controlling the polymer architecture. Characteristics that have been manipulated include the hydration, mechanical properties, pH responsive swelling, temperature responsive swelling, resistance to nonspecific protein adsorption, and protein conjugation capability. This had led researchers to propose the use of polyampholyte polymers as biosensor platforms, fouling release membranes, drug delivery vehicles, and tissue engineering scaffolds. This review is focused on advances that have been made over the last 5 years to develop polyampholyte polymers for these biomedical applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40069.  相似文献   

9.
Recent advances in polymer shape memory   总被引:1,自引:0,他引:1  
Tao Xie Author Vitae 《Polymer》2011,52(22):4985-5000
Traditional shape memory polymers (SMPs) are those capable of memorizing a temporary shape and recovering to the permanent shape upon heating. Although such a basic concept has been known for half a century, recent progresses have challenged the conventional understanding of the polymer shape memory effect and significantly expanded the practical potential of SMPs. In this article, notable recent advances in the field of SMPs are highlighted. Particular emphasis is placed on how the new developments have changed the conventional view of SMPs, what they mean for practical applications, and where the future opportunities are.  相似文献   

10.
孙寒雪  禅文君 《精细化工》2021,38(12):2432-2437,2464
共轭微孔聚合物(CMPs)是典型的多孔有机聚合物,具有丰富的微纳孔和结构可调控性.具有二维结构的CMPs膜材料既保留了CMPs材料的π-共轭骨架和纳米多孔结构,又兼具二维材料优异的可加工性.重点总结了近年来CMPs膜材料的制备方法,包括电化学法、界面聚合法、模板法等;同时介绍了CMPs膜材料在纳滤、分离、抑菌等领域的应用现状;最后指出宏观大尺度CMPs膜的制备技术开发及其微观结构、化学组成与性能调控是未来二维CMPs膜材料的重点发展方向.  相似文献   

11.
PolyHIPEs: Recent advances in emulsion-templated porous polymers   总被引:1,自引:0,他引:1  
Porous polymers with well-defined porosities and high specific surface areas in the form of monoliths, films, and beads are being used in a wide range of applications (reaction supports, separation membranes, tissue engineering scaffolds, controlled release matrices, responsive and smart materials) and are being used as templates for porous ceramics and porous carbons. The surge in the research and development of porous polymer systems is a rather recent phenomenon. PolyHIPEs are porous emulsion-templated polymers synthesized within high internal phase emulsions (HIPEs). HIPEs are highly viscous, paste-like emulsions in which the major, “internal” phase, usually defined as constituting more than 74% of the volume, is dispersed within the continuous, minor, “external” phase. This review focuses upon the recent advances in polyHIPEs involving innovations in polymer chemistry, macromolecular structure, multiphase architecture, surface functionalization, and nanoparticle stabilization. The effects of these innovations upon the natures of the resulting polyHIPE-based materials (including bicontinuous polymers, nanocomposites, hybrids, porous ceramics, and porous carbons) and upon the applications involving polyHIPEs are discussed. The advances in polyHIPEs described in this review are now being used to generate new families of porous materials with novel porous architectures and unique properties.  相似文献   

12.
Inorganic-organic hybrid polymers were prepared by co-polymerization of styrene or methyl methacrylate in the presence of small proportions of the cluster Zr4O2(methacrylate)12. The thermal properties of the hybrid polymers were improved by the cluster-crosslinking. Variation of the reaction conditions had little influence on the thermal properties, although the gelation times were clearly influenced. The cluster-crosslinks were completely and selectively degraded by means of acetylacetone. This allowed the unique possibility of determining the number average molecular weights and polydispersities of the organic polymers which were initially interconnected by the clusters.  相似文献   

13.
星形聚合物的发展近况   总被引:5,自引:1,他引:5  
综述了采用负离子聚合技术合成的星形聚合物的结构与性能的关系、合成路线及应用。新开发的星形聚合物,如SSBR,LCBR,MVBR,HVBR,SIBR等,运用高分子分子设计的方法来合成,因而具有更佳的综合性能,如高的抗湿滑性及低的滚动阻力等。  相似文献   

14.
指出了新的聚合物和聚合系统继续引导着皮肤护理技术的革新,综述了一些诸如自动加热配方、硅对皮肤的感觉、增稠剂、流变改性剂、清洁剂、擦拭剂、洗面奶、保湿霜、防腐配方、聚合抗菌剂和紫外吸收聚合物等化妆品配方师感兴趣的配方组分。  相似文献   

15.
Food security as a world issue has received increasing concern, and therefore, effective analytical methods and technologies have been continuously developed. However, the matrix complexity of food samples and the trace/ultratrace presence of targeted analytes require highly efficient cleanup and enrichment materials and procedures. Molecularly imprinted polymers (MIPs) with specific recognition abilities as versatile materials are being increasingly developed for diverse species in various fields, especially in food analysis. In this review, we mainly summarize the recent advances in MIPs used for food matrices over the last 5 years. We focus on toxic and harmful substances, such as pesticide/drug residues, heavy metals, microbial toxins, and additives. Some relatively new preparation methods involving surface imprinting, composites, and stimuli responsiveness are reviewed. Different MIPs as solid‐phase adsorbents in solid‐phase extraction, solid‐phase microextraction, matrix solid‐phase dispersion, stirring bar sorptive extraction, and magnetic material extraction and as stationary phases in chromatographic separation for foodstuff have been comprehensively summarized. MIP‐based biomimetic sensing and enzymelike catalysis receive special attention. Moreover, some limitations and comparisons related to MIPs performances are also discussed. Finally, some significant attempts to further promote MIP properties and applications to ensure food safety are discussed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40766.  相似文献   

16.
Polymer alloys and blends represent one of the fastest growing sectors of the plastics industry. To a large degree, the emphasis has now shifted from developing blends in the reactor to their creation through melt mixing on processing equipment such as extruders. As a result, intense activity is now being directed at controlling two particularly important considerations during melt processing: interfacial interactions and dispersed phase morphology. In this review, recent developments and trends in these two areas will be examined.  相似文献   

17.
The development of viable alternatives to petroleum-based polymeric materials is a compelling contemporary challenge attributable to environmental concerns and the effects of fluctuating oil prices. Triglycerides, the primary components of vegetable oils, are an abundant, renewable, and widely investigated alternative feedstock for polymeric materials. Efforts are made on a global scale to develop innovative technologies to transform these natural resources into novel monomers and polymers. Some of these technologies have already generated competitive industrial products with properties comparable to conventional petrochemical polymers. Fillers and fibers have also been incorporated into these bio-based polymer matrices to improve the physical and thermal-mechanical properties of the resulting composite materials. The development of multifunctional composite materials facilitates the application of these materials in new areas, e.g., sensors, structural parts, medical device, construction units, flame retardant parts. This article reviews recent advances in polymeric materials from vegetable oils in terms of preparation, characterization, and properties. Nano-composites and fiber reinforced composites based on bio-polymers matrices will also be reviewed. This chapter will conclude with an overview of current and potential future applications of these materials in packaging, automotive, construction, electrical, and medical devices.  相似文献   

18.
含磷本质阻燃高聚物研究进展   总被引:1,自引:0,他引:1  
本质阻燃高聚物阻燃效能持久,不存在挥发、溶出及迁移的问题,且可实现分子内协同阻燃效应,又为环境兼容,故近年日益崭露头角。文中综述了这方面的一些最新研究进展,包括本质阻燃环氧树脂、聚酰胺、聚酰亚胺及聚氨酯等,它们均为分子主链或侧链带含磷基团的无卤型高聚物。文中主要介绍了其合成方法及性能。  相似文献   

19.
Heavy metal ion is one of the major environmental pollutants. In this study, a Cu(II) ions imprinted magnetic chitosan beads are prepared to use chitosan as functional monomer, Cu(II) ions as template, Fe3O4 as magnetic core and epichlorohydrin and glutaraldehyde as crosslinker, which can be used for removal Cu(II) ions from wastewater. The kinetic study shows that the adsorption process follows the pseudo-second-order kinetic equations. The adsorption isotherm study shows that the Langmuir isotherm equation best fits for the monolayer adsorption processes. The selective adsorption properties are performed in Cu(II)/Zn(II), Cu(II)/Ni(II), and Cu(II)/Co(II) binary systems. The results shows that the IIMCD has a high selectivity for Cu(II) ions in binary systems. The mechanism of IIMCD recognition Cu(II) ions is also discussed. The results show that the IIMCD adsorption Cu(II) ions is an enthalpy controlled process. The absolute value of ΔH (Cu(II)) and ΔS(Cu(II)) is greater than ΔH (Zn(II), Ni(II), Co(II)) and ΔS (Zn(II), Ni(II), Co(II)), respectively, this indicates that the Cu(II) ions have a good spatial matching with imprinted holes on IIMCD. The FTIR and XPS also demonstrates the strongly combination of function groups on imprinted holes in the suitable space position. Finally, the IIMCD can be regenerated and reused for 10 times without a significantly decreasing in adsorption capacity. This information can be used for further application in the selective removal of Cu(II) ions from industrial wastewater.  相似文献   

20.
The synthesis of methacrylate stars by an arm-first process using ethylene glycol dimethacrylate as the core-forming material is described. The level of free arm is an indicator for the extent of termination during the preparation. Using 0.2% (mole basis) of catalyst on initiator instead of higher concentration is helpful. Modifiers for the anion catalyst used in group transfer polymerization (GTP) can be used to reduce termination. Clarity of the two-phase blends with polyester polyol and isocyanate crosslinking agent depended on star composition, hydroxyl-number (OH#) and star level. Recently, benzyl methacrylate has been introduced into this technology to give improved film hardness and clarity with cycloaliphatic polyester coreactants. This permits use of 25–30% star to give fast dry and improved hardness/flexibility balance while also allowing the application at less than 3.5 Ib/gallon of solvent.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号