Bioresorbable and bioactive polymer/Bioglass® composites with tailored pore structure for tissue engineering applications

An overview about the development of porous bioresorbable composite materials for applications as scaffolds in tissue engineering is presented. A thermally induced phase separation method was developed to fabricate porous foam-like structures of poly(lactide-co-glycolide) (PLGA) containing bioactive glass particle additions (up to 50 wt.%) and exhibiting well-defined, oriented and interconnected porosity. The in vitro bioactivity and the degradability of the composite foams were investigated in contact with phosphate buffer saline (PBS). Weight loss, water absorption and molecular weight measurements were used to monitor the polymer degradation after incubation periods of up to 7 weeks in PBS. It was found that the presence of bioactive glass retards the polymer degradation rate for the time period investigated. The present results show a way of controlling the in vitro degradation behaviour of PLGA porous composite scaffolds by tailoring the concentration of bioactive glass.     

Polymer Photovoltaics with Alternating Copolymer/Fullerene Blends and Novel Device Architectures

The synthesis of novel conjugated polymers, designed for the purpose of photovoltaic energy conversion, and their properties in polymer/fullerene materials and photovoltaic devices are reviewed. Two families of main‐chain polymer donors, based on fluorene or phenylene and donor–acceptor–donor comonomers in alternating copolymers, are used to absorb the high‐energy parts of the solar spectrum and to give high photovoltages in combinations with fullerene acceptors in devices. These materials are used in alternative photovoltaic device geometries with enhanced light incoupling to collect larger photocurrents or to enable tandem devices and enhance photovoltage.     

刚性棒状金属有机聚合物

综述了在主链上含有过渡金属和刚性共轭有机桥的聚合物,即所谓的刚性棒状金属有机聚合物的种类、制备、性质及应用。     

亚芳基环烷酮聚合物的研究进展

本文对亚芳基聚合物的研究现状进行了概述,着重介绍了含亚芳基聚合物的合成和性质的研究进展。     

树枝形聚合物/线性聚合物共混的研究进展

综述了国内外有关树枝形聚合物／线性聚合物共混物的形态结构、热性能、动态力学性能、流变性能和物理力学性能的研究进展，树枝形聚合物因其独特的结构和性能特点，可作为聚合物的加工助剂、流变学改性剂、增容剂以及增强或增韧剂。     

聚合物接枝碳纳米管的研究进展

本文综述了线性聚合物及超支化聚合物接枝碳纳米管的研究现状,着重介绍了直接引入法、表面引发聚合法、分步增长法及与点击化学技术相结合的方法,并指出了其发展前景。     

Optically Transparent Multiscale Composite Films for Flexible and Wearable Electronics

One of the key breakthroughs enabling flexible electronics with novel form factors is the deployment of flexible polymer films in place of brittle glass, which is one of the major structural materials for conventional electronic devices. Flexible electronics requires polymer films with the core properties of glass (i.e., dimensional stability and transparency) while retaining the pliability of the polymer, which, however, is fundamentally intractable due to the mutually exclusive nature of these characteristics. An overview of a transparent fiber-reinforced polymer, which is suggested as a potentially viable structural material for emerging flexible/wearable electronics, is provided. This includes material concept and fabrication and a brief review of recent research progress on its applications over the past decade.     

Semiconducting (Conjugated) Polymers as Materials for Solid‐State Lasers

Light‐emissive polymers are outstanding laser materials because they are intrinsically “4‐level” systems, they have luminescence efficiencies higher than 60 % even in undiluted films, they emit at colors that span the visible spectrum, and they can be processed into optical quality films by spin casting. The important materials issues are reviewed and the prospects for making polymer diode lasers are discussed.     

Thermotropic and optical properties of chiral nematic polymers

The thermotropic and optical properties of methacrylate copolymers and chemically modified poly(-benzyl L-glutamate) were investigated as part of our effort to explore the optical applications of these materials. It was found that besides the commonly cited comonomer ratio, physical blending and annealing followed by quenching represent a new and more flexible means to tune the selective reflection wavelength. In the chemically modified poly(-benzyl L-glutamate) system with Tg as low as — 25 °C, it appears that the relatively high-melt viscosity is capable of sustaining the cholesteric mesophase, generated by annealing and quenching, while subjected to heating up to 100°C.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Alternating 2,7- and 3,6-linked carbazole copolymers as wide band gap energy transfer donors

An alternating copolymer comprising 3,6-linked-9-(2-ethylhexyl)-9H-carbazole and 2,7-linked-3,6-dimethyl-9-(2-hexyldecy)-9H-carbazole has been prepared using Suzuki cross-coupling conditions. The polymer was characterised by nuclear magnetic resonance spectroscopy, UV-Vis absorption spectroscopy, fluorescence spectroscopy and its weight-average molecular weight was estimated using gel permeation chromatography. The polymer is thermally stable up to 420 °C and displays a wide band gap (3.2 eV) and a narrow emission band at 400 nm with a full width at half maximum of 56 nm. Electroluminescence studies indicated that the polymer emitted principally blue light when blended with 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole and was found to be a good energy transfer donor to bis(2-(2′-benzothienyl)-pyridinato-N,C³′)iridium (acetylacetonate) and provided devices with an efficiency of 0.1 cd/A, and a turn-on voltage of 5.6 V.     

Energy Storage Application of Conducting Polymers Featuring Dual Acceptors: Exploring Conjugation and Flexible Chain Length Effects

Solution-processable conducting polymers (CPs) are a compelling alternative to inorganic counterparts because of their potential for tuning chemical properties and creating flexible organic electronics. CPs, which typically comprise either only an electron donor (D) or its alternative combinations with an electron acceptor (A), exhibit charge transfer behavior between the units, resulting in an electrical conductivity suitable for utilization in electronic devices and for energy storage applications. However, the energy storage behavior of CPs with a sequence of electron acceptors (A–A), has rarely been investigated, despite their promising lower band gap and higher charge carrier mobility. Utilizing the aforesaid concept herein, four CPs featuring benzodithiophenedione (BDD), and diketopyrrolepyrrole (DPP) are synthesized. Among them, the BDDTH-DPPEH polymer exhibited the highest specific capacitance of 126.5 F g⁻¹ at a current density of 0.5 A g⁻¹ in an organic electrolyte over a wide potential window of −0.6–1.4 V. Notably, the supercapacitor properties of the polymeric electrode materials improved with increasing conjugation length by adding thiophene donor units and shortening the alkyl chain lengths. Furthermore, a symmetric supercapacitor device fabricated using BDDTH-DPPEH exhibited a high-power density of 4000 W kg⁻¹ and an energy density of 31.66 Wh kg⁻¹.     

Conjugated Donor–Acceptor Terpolymers Toward High‐Efficiency Polymer Solar Cells

The development of conjugated alternating donor–acceptor (D–A) copolymers with various electron‐rich and electron‐deficient units in polymer backbones has boosted the power conversion efficiency (PCE) over 17% for polymer solar cells (PSCs) over the past two decades. However, further enhancements in PCEs for PSCs are still imperative to compensate their imperfect stability for fulfilling practical applications. Meanwhile development of these alternating D–A copolymers is highly demanding in creative design and syntheses of novel D and/or A monomers. In this regard, when being possible to adopt an existing monomer unit as a third component from its libraries, either a D′ unit or an A′ moiety, to the parent D–A type polymer backbones to afford conjugated D–A terpolymers, it will give a facile and cost‐effective method to improve their light absorption and tune energy levels and also interchain packing synergistically. Moreover, the rationally controlled stoichiometry for these components in such terpolymers also provides access for further fine‐tuning these factors, thus resulting in high‐performance PSCs. Herein, based on their unique features, the recent progress of conjugated D–A terpolymers for efficient PSCs is reviewed and it is discussed how these factors influence their photovoltaic performance, for providing useful guidelines to design new terpolymers toward high‐efficiency PSCs.