Twin Polymerization—a New Principle for Hybrid Material Synthesis

Twin polymerization is a novel modular approach for the synthesis of hybrid materials. Using this strategy two distinct polymers of either inorganic or organic nature are produced from a single source monomer in a mechanistically coupled process. Twin polymerization is an elegant way for producing nanostructured organic‐inorganic hybrid materials of composition and morphology on demand. The main objective of this Review is the explanation of the principle of various twin polymerization processes and their appropriate terminologies. Different types of twin polymerization are classified with respect to the underlying processes as described in individual examples, demonstrating its potential in material synthesis. Prospects of the synthetic methodology of twin polymerization are demonstrated for different molecular structures of twin monomers and the resulting hybrid materials. A comparison with other scenarios for the synthesis of two different polymers within one procedure is included.

     

Luminescent Properties of a Silicone-Carbazolyl Polyfluorene Hybrid Material for Device Applications

In the present work, bilayered hybrids obtained by hydrosilylation of polysiloxane with carbazolyl moieties (Sil-Cz) and polyfluorene (Sil-PFO) had their photophysical behavior, morphological characteristics and interaction properties studied for applications in electroluminescent devices. Fluorescence spectra of the Sil-Cz did not show emission in the excimer/aggregate region (from 400 to 500 nm). This is an unexpected behavior since most of the carbazole-based materials present excimer and aggregation. Nonetheless, this unusual observation was also predicted by geometry optimization calculations. Fluorescence spectra were taken for both compounds separately and for the bilayered system show some evidence of interaction between carbazolyl and polyfluorene moieties, giving rise to the supposition that the can form a system with tunable luminescent properties.     

Luminescent Hybrid Materials Based on Laponite Clay

The spectroscopic behavior of ionic Eu³⁺ or Tb³⁺ complexes of an aromatic carboxyl‐functionalized organic salt as well as those of the hybrid materials derived from adsorption of the ionic complexes on Laponite clay are reported. X‐ray diffraction (XRD) patterns suggest that the complexes are mainly adsorbed on the outer surfaces of the Laponite disks rather than intercalated within the interlayer spaces. Photophysical data showed that the energy‐transfer efficiency from the ligand to Eu³⁺ ions in the hybrid material is increased remarkably with respect to the corresponding ionic complex. The hybrid material containing the Eu³⁺ complex shows bright red emission from the prominent ⁵D₀→⁷F₂ transition of Eu³⁺ ions, and that containing the Tb³⁺ complex exhibits bright green emission due to the dominant ⁵D₄→⁷F₅ transition of Tb³⁺ ions.     

Polymer Based Nanocomposites with PhenethylPOSS as Nanofiller Investigated by Dielectric Spectroscopy and Gas Transport Measurements

Polyhedral oligomeric silsesquioxane with phenethyl substituents (PhenethylPOSS) as nanofiller was incorporated within Poly(bisphenol A carbonate) (PBAC) as matrix. Dielectric spectroscopy proved an almost complete miscibility of PhenethylPOSS up to 7 wt. %. At higher concentrations phase separation yields composites with a PBAC-rich matrix and POSS-rich domains which posses well shaped interfaces. The nanocomposites were also investigated with respect to their gas transport behaviour. An increase of the gas permeability was found at higher PhenethylPOSS concentrations, which is due to the phase separated structure.     

Electrochemical Growth of Conducting Polymer into Zirconium Oxopolymers Sol-Gel Coatings

Conducting polymer based hybrid materials were synthesized by a new route. The use of pyrrole derivatives functionalized by a carboxylic acid or a -diketone group allows to control the polymerization rate of zirconium tetrapropoxide (Zr(OPr)₄). The organic species entrapped in the resulting hybrid materials yield conducting polymers by electropolymerization. The results show that the formation of the conducting polymers depends on the nature of the monomer. Moreover, the presence of polysiloxane chains within the hybrid materials improves the properties of the latter.     

2005年我国内地学者高分子科学基础研究进展概述

简要介绍了2005年度我国内地学者在高分子主要前沿领域基础研究的进展，涉及的领域主要包括特殊构筑高分子的合成、高分子结构表征、光电功能高分子、高分子自组装与超分子聚合物、高分子微纳结构与纳米复合体系、类细胞膜融合分裂的实时观测和生物医用高分子等。     

High‐Efficiency Large‐Bandgap Material for Polymer Solar Cells

High‐molecular‐weight conjugated polymer HD‐PDFC‐DTBT with N‐(2‐hexyldecyl)‐3,6‐difluorocarbazole as the donor unit, 5,6‐bis(octyloxy)benzothiadiazole as the acceptor unit, and thiophene as the spacer is synthesized by Suzuki polycondensation. HD‐PDFC‐DTBT shows a large bandgap of 1.96 eV and a high hole mobility of 0.16 cm² V⁻¹ s⁻¹. HD‐PDFC‐DTBT:PC₇₁BM‐based inverted polymer solar cells (PSCs) give a power conversion efficiency (PCE) of 7.39% with a V_oc of 0.93 V, a J_sc of 14.11 mA cm⁻², and an FF of 0.56.

     

Polyaniline as a Material for Hydrogen Storage Applications

The main challenge of commercialization of the hydrogen economy is the lack of convenient and safe hydrogen storage materials, which can adsorb and release a significant amount of hydrogen at ambient conditions. Finding and designing suitable cost‐effective materials are vital requirements to overcome the drawbacks of investigated materials. Because of its outstanding electronic, thermal, and chemical properties, the electrically conducting polyaniline (PANI) has a high potential in hydrogen storage applications. In this review, the progress in the use of different structures of conducting PANI, its nanocomposites as well as activated porous materials based on PANI as hydrogen storage materials is presented and discussed. The effect of the unique electronic properties based on the π‐electron system in the backbone of these materials in view of the hydrogen uptake and the relevant mechanisms are highlighted.

     

杂化材料的制备、性能及应用

较详细地介绍了杂化材料的概念及其制备方法、性能和应用。重点是有机高分子－无机杂化材料的制备、性能及应用。     

Synthesis and Characterization of a Thermoresponsive Polyoxometalate–Polymer Hybrid

We report the synthesis of the first organo‐POM with thermoresponsive properties. Our concept will provide chemists with a new tool to design POMs whose solubility is reversibly controllable through an external stimulus. POM–polymer TBA₇[POM]‐poly(N,N‐diethylacrylamide) (POM–PDEAAm), was prepared by grafting PDEAAm‐NH₂ (obtained by RAFT polymerization) onto the activated Dawson acyl‐POM, α₂‐[P₂W₁₇O₆₁SnCH₂CH₂C(?O)]^6?. Extensive MS analysis was used to monitor the chain‐functionalization steps and to confirm the formation of the hybrid. Aqueous solutions of the (NH₄)₇[POM–PDEAAm] exhibited a LCST of 38 °C. Thus, the solubility/aggregation of the hybrid was reversibly controlled by changing the temperature. Above 38 °C, the solution became cloudy, and cleared again upon cooling. Dynamic light scattering (DLS) revealed the formation of small aggregates in the range 100 nm. We assumed that the charged POM head units prevented the formation of the larger‐scattering aggregates that are usually observed for PDEAAm, and promoted the formation of micelle‐like structures. The conjugate exhibited a temperature transition, which was different from that of the polymer and depended on the counterions associated with the POM. This result demonstrates the potential for merging organic (in this case, polymer) and inorganic structures to afford materials that exhibit new properties.     

Photoactive Polythiophene:Titania Hybrids with Excellent Miscibility for Use in Polymer Photovoltaic Cells

A series of poly{(3‐hexylthiophene)‐co‐[3‐(6‐hydroxyhexyl)thiophene]}:titania (P3HT‐OH:TiO₂) hybrids were synthesized via the in situ polycondensation of titanium (IV) n‐butoxide in the presence of P3HT‐OH. Introducing a hydroxyl moiety onto the side‐chain of poly(3‐hexylthiophene) (P3HT) significantly promotes the polymer‐titania interaction, resulting in the formation of homogeneous hybrid colloids. The UV‐vis spectra of P3HT‐OH:TiO₂ films demonstrate that TiO₂ markedly affects the stacking structure and the chain conformation of P3HT‐OH. The maximum absorption wavelength of these hybrid materials can be tailor‐made by merely varying the weight percentage of TiO₂. Moreover, P3HT‐OH:TiO₂ can be further utilized as an efficient compatibilizer in preparing photoactive P3HT:P3HT‐OH:TiO₂ films with excellent miscibility. The photovoltaic cell based on such a hybrid exhibited a 2.4‐fold higher value of power‐conversion efficiency compared to the cell based on P3HT:TiO₂.

     

Role of the Polymer Matrix on the Photoluminescence of Embedded CdSe Quantum Dots

The photoluminescence (PL) of CdSe quantum dots (QDs) that form stable nanocomposites with polymer liquid crystals (LCs) as smectic C hydrogen‐bonded homopolymers from a family of poly[4‐(n‐acryloyloxyalkyloxy)benzoic acids] is reported. The matrix that results from the combination of these units with methoxyphenyl benzoate and cholesterol‐containing units has a cholesteric structure. The exciton PL band of QDs in the smectic matrix is redshifted with respect to QDs in solution, whereas a blueshift is observed with the cholesteric matrix. The PL lifetimes and quantum yield in cholesteric nanocomposites are higher than those in smectic ones. This is interpreted in terms of a higher order of the smectic matrix in comparison to the cholesteric one. CdSe QDs in the ordered smectic matrix demonstrate a splitting of the exciton PL band and an enhancement of the photoinduced differential transmission. These results reveal the effects of the structure of polymer LC matrices on the optical properties of embedded QDs, which offer new possibilities for photonic applications of QD–LC polymer nanocomposites.     

重要传感材料荧光共轭聚合物PPESO3的一种新的简便合成路线

本文提出了一种新的简便得多的合成路线, 既避免了BBr3的使用, 又简化了反应步骤, 使PPESO3的合成简单易行, 为更广泛地对其进行研究与应用提供了便利条件. 此外, 本文还研究了PPESO3与非离子表面活性剂(聚乙烯吡咯烷酮, PVP)之间的相互作用, 结果表明, PVP与PPESO3形成了稳定的络合体, 可以有效地打破聚合物在水溶液中的聚集, 提高荧光量子产率.     

Nitrogen-Linked Hexaazatrinaphthylene Polymer as Cathode Material in Lithium-Ion Battery

Nitrogen-linked hexaazatrinaphthylene polymer ( N²-HATN ) as organic cathode material with low HOMO–LOMO gap was synthesized and was observed to possess reversible high capacity and unexpected long-term cycling stability. The pre-treated N²-HATN and pRGO combination demonstrated good structure compatibility and the resultant cathode exhibited a constant increment of capacity during the redox cycles. The initial capacity at 0.05 A g⁻¹ was 406 mA h⁻¹ g⁻¹, and increased to 630 mA h⁻¹ g⁻¹ after 70 cycles. At 0.5 A g⁻¹ discharging rate, the capacity increased from an initial value of 186 mA h⁻¹ g⁻¹ to 588 mA h⁻¹ g⁻¹ after 1600 cycles. The pseudocapacitance-type behavior is postulated to be attributed to the structure compatibility between the active material and pRGO.     

Reactive Polymer as a Versatile Toolbox for Construction of Multifunctional Superparamagnetic Nanocomposites

The development of magnetic nanoparticles with multiple functions has been an ever‐growing field because of their diverse applications in drug delivery, biosensing, cell labeling, and so on. In this study, a facile method was developed to construct multifunctional magnetic nanocomposites. The approach is based on the use of poly(glycidyl methacrylate), PGMA, with numerous epoxy groups as reactive polymer to combine with fluorescent dye, the surface of magnetic nanoparticles, and targeting ligands directly without expatiatory functionality design. The resultant nanocomposites with good superparamagnetic and fluorescent properties could be exploited for bioimaging. Moreover, after conjugation with a model protein, namely, transferrin, which specifically targets cells overexpressing transferrin receptors, the nanocomposites could be used selectively to recognize Hela cells in comparison with nonconjugated ones. These results indicate that the newly designed magnetic nanocomposites with PGMA as functional polymer could serve as a novel versatile platform to conjugate with various molecules for construction of diverse multifunctional magnetic nanocomposites to meet different requirements and potential uses in nanomedicine and biological chemistry.     

Mixed Hybrid Lipid/Polymer Vesicles as a Novel Membrane Platform

Vesicles can be individually fabricated from naturally occurring lipid or synthetic block copolymer molecules via self‐assembly in aqueous solutions; the blending of both vesicle‐forming amphiphiles leads to the formation of hybrid membranes. Their final stabilities and lateral morphologies are strongly determined by the molar composition, size, and charge properties of the interacting components as well as by the lipid chain melting temperature. Upon merging the best properties of lipo‐ and polymersomal membranes, hybrid lipid/polymer vesicles represent a new scaffold for medical applications combining, e.g., combining the biocompatibility of liposomes with the high thermal and mechanical stability and functional variability of polymersomes within a single vesicle type. Up to now, several hybrid membrane systems and their corresponding vesicular morphologies have been studied, highlighting the attractive properties and features useful in selective delivery receptor scaffolding.