功能型聚合物光子晶体的制备及应用

光子晶体因其特殊的光调控性能,在各类高性能光学器件方面具有重要的应用前景.本文主要阐述了功能型聚合物光子晶体的制备方法及其在防护涂层、高效发光、高灵敏检测和高性能光信息存储等方面的应用.     

Synthesis of a novel one‐pot approach of hyperbranched polyurethanes and their properties

A new method for the synthesis of hyperbranched polymers involving the use of AB_x macromonomers containing linear units have been investigated. Two types of novel hyperbranched polyurethanes have been synthesized by a one‐pot approach. The structures of monomers and polymers were characterized by elemental analysis, ¹H NMR, ¹³C NMR, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The hyperbranched polymers have been proven to be extremely soluble in a wide range of solvents. Polymer electrolytes were prepared with hyperbranched polymer, linear polymer as the host, and lithium perchlorate (LiClO₄) as the ion source. Analysis of the isotherm conductivity dependence of the ion concentration indicated that these hyperbranched polymers could function as a “solvent” for the lithium salt. The conductivity increased with the increasing concentration of hyperbranched polymers in the host polymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 344–350, 2002     

Recent progress in chiral photonic band‐gap liquid crystals for laser applications

This article describes a brief review of recent research advances in chiral liquid crystals (CLCs) for laser applications. The CLC molecules have an intrinsic capability to spontaneously organize supramolecular helical assemblages consisting of liquid crystalline layers through their helical twisting power. Such CLC supramolecular helical structures can be regarded as one‐dimensional photonic crystals (PhCs). Owing to their supramolecular helical structures, the CLCs show negative birefringence along the helical axis. Selective reflection of circularly polarized light is the most unique and important optical property in order to generate internal distributed feedback effect for optically‐excited laser emission. When a fluorescent dye is embedded in the CLC medium, optical excitation gives rise to stimulated laser emission peak(s) at the band edge(s) and/or within the CLC selective reflection. Furthermore, the optically‐excited laser emission peaks can be controlled by external stimuli through the self‐organization of CLC molecules. This review introduces the research background of CLCs carried out on the PhC realm, and highlights intriguing precedents of various CLC materials for laser applications. It would be greatly advantageous to fabricate active CLC laser devices by controlling the supramolecular helical structures. Taking account of the peculiar features, we can envisage that a wide variety of supramolecular helical structures of CLC materials will play leading roles in next‐generation optoelectronic molecular devices. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.201000013     

Mechanical and flame‐retardant properties of biodegradable polylactide composites with hyperbranched silicon‐containing polymer

A hyperbranched polymer (HBP‐B2) containing siloxane chains was synthesized via bulk polymerization of diepoxide with a primary amine in the presence of monoepoxide. The weight‐average molecular weight of the prepared polymers was approximately 9200. Composites of polylactide (PLA) with aluminum trihydroxide (ATH) and the HBP‐B2 were prepared via direct melt compounding using a brabender. The test results showed that the LOI could be raised to 34% for the PLA composite with 25 wt% ATH and 5% HBP‐B2. The surface thermal profile of the composite during UL94 V test was further captured by an infrared camera, which was helpful to understand the flame‐retardant properties of the different samples. A V‐0 rating could be achieved by adding ATH and HBP‐B2 to the PLA matrix. Incorporation of HBP‐B2 as a plasticizer could increase the impact strength of a PLA blend or composite. For example, an addition of 10 wt% of HBP and 20 wt% ATH increased the elongation at break from 5% for neat PLA to 155% for the PLA composite.     

An approach to one‐dimensional conductive polymer composites

A substantial approach to one‐dimensional (1D) electrically conductive composites was proposed which was based on the thermodynamic analysis of electric‐field‐induced particle alignment in a nonpolar thermoplastic polymer matrix. The process condition window was based on the real‐time exploration of dynamic percolation under different electric fields with carbon black (CB)‐filled polyethylene as a model. The CB content was the main factor of the process condition. Its upper limit was set as the critical percolation concentration at the thermodynamic equilibrium state without an electric field to eliminate the possibility of conductive network formation perpendicular to the electric‐field direction, whereas its lower limit the critical percolation concentration at the thermodynamic equilibrium state under a critical electric field (E*). A composite with CB content in this window, isothermally treated in an electric field not less than E*, showed conductivity in the electric‐field direction about 10⁵ times larger than that in the perpendicular direction. A 1D cluster structure in the direction of the electric filed was confirmed with scanning electron microscopy morphology observations. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 184–189, 2005     

Improved mechanical properties of epoxy‐based composites with hyperbranched polymer grafting glass‐fiber

A glass‐fiber, grafted by hyperbranched polymer with hydroxyl group (GF‐HBPH), reinforced epoxy‐based composite was evaluated for mechanical properties and compared with the neat epoxy and silanized glass‐fiber, GF‐APS. The epoxy/GF‐HBPH composites were studied by attenuated total internal reflectance infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy, thermal gravimetric analysis, mechanical properties analysis, and field emission‐scanning electron microscopy. The results showed that the incorporation of GF‐HBPH could simultaneously enhance the mechanical properties of the epoxy composites. Field emission‐scanning electron microscopy images of the fracture surfaces of the test specimens were used to support the results and conclusions. Copyright © 2016 John Wiley & Sons, Ltd.     

New poly(phenylenevinylene)‐methyl methacrylate‐based photonic crystals

Monodisperse colloids have been prepared efficiently by copolymerization of methyl methacrylate and fluorescent first‐ and second‐generation poly(phenylenevinylene) dendrons under surfactant‐free emulsion polymerization conditions. The copolymers were characterized by UV–vis and fluorescence spectroscopy and size exclusion chromatography. Transmission electron microscopy revealed that the copolymers were microspheres with smooth surfaces and narrow dispersity. The bead diameter could be varied by changing the monomer/water ratio. The materials could be crystallized to give polymer opal photonic crystals. The emission was not affected by the periodic structure because of the large spectral distance between the emission and the pseudogap position. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2659–2665, 2010     

Three‐dimensional structure in holographic polymer‐dispersed liquid crystals

Polymer‐dispersed liquid crystals, heterogeneous structures consisting of a liquid crystal and a polymer, are promising materials for generating holograms with switchable diffraction efficiency. The experiments presented here reveal that the generation of a face‐centered cubic structure can be achieved by exposing a liquid crystal/reactive monomer mixture to the interference pattern of four coherent laser beams under appropriate geometrical conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

A hyperbranched,rotaxane‐type mechanically interlocked polymer

Based on the dibenzo‐24‐crown‐8/1,2‐bis(pyridinium)ethane recognition motif, a hyperbranched mechanically interlocked polymer was prepared by polyesterification of an easily available dynamic trifunctional AB₂ pseudorotaxane monomer. It was characterized by various techniques including ¹H NMR, COSY, NOESY, GPC, viscosity, TGA, dynamic laser light scattering, AFM, and SEM. Its GPC M_n was determined to be 191 kDa with polydispersity 1.7 and its hydrodynamic diameter in a dilute solution in acetone was about 70 nm. This measured M_n value corresponds to about 93 repeating units. The study reported here presents not only a new polymer topology but also a novel and convenient way to prepare mechanically interlocked polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4067–4073, 2010     

Modulation of spontaneous emission characteristics of Alq3 in three‐dimensional PMMA photonic crystals

The effect of the photonic stop bands (PSBs) on the spontaneous emission from tris(8‐hydroxyquinolinato)aluminum (Alq3) doped in the beads of polymethylmethacrylate opal photonic crystals (PCs) is investigated in detail. The structure of PSBs in PCs has been analyzed. The steady emission data exhibits that the first‐ and second‐order PSB could effectively influence the spectral characteristics of Alq3 through changing the incident angles. The emission dynamic data is also investigated by using the Kohlrausch strengthened exponential model, which shows that the emission decay rate of Alq3 can be decelerated as the PSB of PC approaches the emission peak of Alq3. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 842–847     

A coordination polymer consisting of two different one‐dimensional copper(II) chains

The title compound, catena‐poly[[[diaqua(methanol‐κO)copper(II)]‐μ‐N‐(4‐methylpyrimidin‐2‐yl‐κN¹)pyrazin‐2‐amine‐κ²N¹:N⁴] [[aqua(aqua/methanol‐κO)(perchlorato‐κO)copper(II)]‐μ‐N‐(4‐methylpyrimidin‐2‐yl‐κN¹)pyrazin‐2‐amine‐κ²N¹:N⁴] tris(perchlorate) methanol monosolvate 1.419‐hydrate], {[Cu(C₉H₉N₅)(CH₃OH)(H₂O)₂][Cu(C₉H₉N₅)(ClO₄)(CH₃OH)_0.581(H₂O)_1.419](ClO₄)₃·CH₃OH·1.419H₂O}_n, is a one‐dimensional straight‐chain polymer of N‐(4‐methylpyrimidin‐2‐yl)pyrazin‐2‐amine (L) with Cu(ClO₄)₂. The complex consists of two crystallographically independent one‐dimensional chains in which the Cu^II atoms exhibit two different octahedral coordination geometries. The L ligand coordinates to two Cu^II centres in a tridentate manner, with the pyrazine ring acting as a bridge linking the Cu^II coordination units and building an infinite one‐dimensional chain. Extensive hydrogen bonding among perchlorate anions, water molecules and L ligands results in three‐dimensional networks.     

Optical and physical properties of iridescent photonic crystals obtained by self‐assembled polymethyl methacrylate nanospheres within graphene oxide nanoplatelets

Opal photonic crystals prepared by vertical templating of polymethyl methacrylate (PMMA) nanospheres in aqueous graphene oxide (GO) solutions were successfully obtained. The results show that increasing the PMMA nanospheres' size leads to the modification of the d‐spacing in GO nanoplatelets, inducing brilliant iridescence colors that span the entire visible electromagnetic spectrum. Scanning electron microscopy study shows a uniform distribution of GO nanoplatelets on the surface and the bulk of the opal photonic crystals. The reflectance spectra exhibit a significant red shift from 385 to 660 nm when the nanospheres' size increases from 160 to 306 nm, respctively. The Raman spectra show a systematic decrease in the intensity ratio of the D to G bands of GO (I_D/I_G), suggesting a partial reduction of graphene oxide with decrasing the extent of defects in the partially reduced GO nanoplatelets. This finding is confirmed by the significant decrease observed in the intensity of the hydroxyl band in the attenuated total reflectance mode‐Fourier transform infrared spectra of the photonic crystals. The results provide the first demonstrated example of intercalated assemblies of polymer nanospheres within GO nanosheets, leading to photonic crystals with brilliant iridescence colors that span the entire visible electromagnetic spectrum and can be tuned only by varying the size of the PMMA nanospheres.     

A new polymer acceptor containing naphthalene diimide and 1,3,4‐thiadiazole for all‐polymer solar cells

A n‐type conjugated polymer containing naphthalene diimide (NDI) and 1,3,4‐thiadiazole (TZ) moieties, named PNTZ, has been synthesized and applied for all‐polymer solar cells (all‐PSCs). By the incorporation of TZ unit into the polymer main chains, the lowest unoccupied molecular orbital level of this polymer has been adjusted effectively. In addition, the electron‐acceptor PNTZ shows a broad absorption spectrum in the range of 300–700 nm, and possesses complementary absorption spectrum with the electron‐donor PTB7‐Th. On the basis of PNTZ as the acceptor and PTB7‐Th as the donor, the all‐PSCs are fabricated. After optimization, the well blend morphologies with a continuous D/A interpenetrating network are observed and the best all‐PSC device exhibits a power conversion efficiency of 4.35% with a high short‐circuit current density of 13.26 mA cm^?2. This research demonstrates that the TZ‐containing polymer PNTZ is a promising non‐fullerene acceptor for high efficiency all‐PSCs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 990–996     

β‐Cyclodextrin polymer brushes based on hyperbranched polycarbosilane: Synthesis and characterization

In this article, our main goal is to combine hyperbranched polymer with β‐cyclodextrin (β‐CD) to establish a novel functional polymer species with core‐shell structure and supramolecular system for further application in inclusion technologies and the complex drugs delivery system. Therefore, two β‐CD polymer brushes based on hyperbranched polycarbosilane (HBP) as a hydrophobic core and poly(N,N‐dimethylaminoethyl methacrylate) (PDMA) carrying β‐CD units as a hydrophilic shell were synthesized. Hyperbranched polycarbosilane macroinitiator carrying ? Cl groups (HBP‐Cl) was also prepared by using 1,1,3,3‐tetrmethyldisiloxane, allyl alcohol, and chloroacetyl chloride as reagents. The molecular structures of HBP‐Cl macroinitiator and β‐CD polymer brushes were characterized by Fourier transform infrared spectroscopy (FTIR), ¹H nuclear magnetic resonance (¹H NMR), ¹³C nuclear magnetic resonance (¹³C NMR) spectroscopies, size exclusion chromatography/multi‐angle laser light scattering (SEC/MALLS) and laser particle size analyzer. The results indicate that the grafted chain length of two β‐CD polymer brushes can be controlled by changing the feed ratio. Differential scanning calorimetry (DSC) results show that two β‐CD polymer brushes have two glass transition temperatures (T_gs) from a hydrophobic core part and a hydrophilic shell part, respectively, and the T_g from PDMA is higher than that of HBP‐g‐PDMA. Thermalgravimetric analyzer (TGA) analysis indicates that the thermostability of two β‐CD polymer brushes is higher than that of HBP, but is lower than that of HBP‐g‐PDMA. Using phenolphthalein (PP) as a guest molecule, molecular inclusion behaviors for two β‐CD polymer brushes were studied. It reveals that two β‐CD polymer brushes possess molecular inclusion capability in PP buffer solution with a fixed concentration. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5036–5052, 2008     

Large electro‐optic activity and enhanced temporal stability of methacrylate‐based crosslinking hyperbranched nonlinear optical polymer

A methacrylate‐based crosslinking hyperbranced polymers have been synthesized through initiator‐fragment incorporation radical polymerization and used for the temperature stable electro‐optic (EO) polymer application. This polymer consists of methyl methacrylate, 2‐metacryloxyethyl isocyanate, and ethylene glycol dimethacrylate (EGDMA) monomers. The use of EGDMA as a bifunctional unit resulted in the solvent‐soluble crosslinking hyperbranched chain, so that the EO polymer enhanced glass transition temperatures. A phenyl vinylene thiophene vinylene bridge nonlinear optical chromophore was attached to the polymer backbone as the side‐chain by a post‐functionalization reaction. The loading concentration of the chromophore was varied between 30 and 50 wt % by simply changing the mixing ratio of the precursor polymer to the chromophore. The synthesized EO polymers produced optical quality films with a light propagation loss of 0.61 dB/cm in a slab waveguide at 1.31 μm. The electrically poled film had an EO coefficient (r₃₃) of 139 pm/V at 1.31 μm. The EO crosslinking hyperbranced polymer had a high‐glass transition temperature of 170 °C, and exhibited excellent temporal stability of the EO activity at 85 °C for 500 h. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Time‐dependent deformation of structurally chiral polymer networks in stabilized cholesteric liquid crystals

Polymerization of crosslinkable liquid crystal monomers in chiral liquid crystalline media stabilizes the phase and enables distinct electro‐optic properties relative to small‐molecule analogs. Particularly interesting are cases where the polymerization forms a crosslinked polymer network that maintains a “structural” chirality. Recent reports have employed this methodology to realize a diverse set of electro‐optic responses in polymer stabilized cholesteric liquid crystals (PSCLCs) including reflection bandwidth broadening, reflection wavelength tuning, and dynamic scattering modes. It has been proposed that the mechanism at the root of these electro‐optic responses is an ion‐mediated, electromechanical deformation of the stabilizing and structurally chiral polymer network. In an effort to better understand the nature of these deformations, here we have characterized the electro‐optic response of PSCLCs with different polymer concentrations and crosslink densities. The dynamic response of PSCLCs to electric fields exhibits a time‐dependent behavior reminiscent of the creep of polymeric materials to mechanical deformations. The electro‐optic response can be described as the superposition of two contributions: the fast deformation of a relatively soft component of the polymer network (1–2 s) and the slower (10–20 s) deformation of a harder component. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1087–1093     

A novel cadmium(II) coordination polymer containing two kinds of independent one‐dimensional chain

The structure of the title compound, catena‐poly[[cadmium(II)‐di‐μ‐chlorido‐μ‐(1,4‐diazoniabicyclo[2.2.2]octane‐1‐carboxylato)] [[aquachloridocadmium(II)]‐di‐μ‐chlorido] dihydrate], {[Cd(C₈H₁₅N₂O₂)Cl₂][CdCl₃(H₂O)]·2H₂O}_n, contains two kinds of independent one‐dimensional chain, viz. {[Cd(C₈H₁₅N₂O₂)Cl₂]⁺}_n and {[CdCl₃(H₂O)]⁻}_n, and uncoordinated water molecules. Each Cd^II cation in the {[Cd(C₈H₁₅N₂O₂)Cl₂]⁺}_n chain is octahedrally coordinated by two pairs of bridging chloride ligands and two O atoms from different bridging carboxylate groups. Cd^II cations in the {[CdCl₃(H₂O)]⁻}_n chain are also octahedrally surrounded by four bridging chloride ligands, one terminal chloride ligand and one coordinated water molecule. Hydrogen bonds between solvent water molecules and these two independent chains generate a three‐dimensional framework containing two‐dimensional zigzag layers.<!?tpb=18pt>     

A one‐dimensional zinc(II) coordination polymer based on mixed multidentate N‐ and O‐donor ligands

In the title coordination polymer, catena‐poly[[bis[{1‐[(1H‐benzimidazol‐2‐yl‐κN³)methyl]‐1H‐tetrazole}zinc(II)]‐bis(μ₄‐pentane‐1,5‐dioato‐1:2:1′:2′κ⁴O¹:O^1′:O⁵:O^5′)] methanol disolvate], {[Zn(C₅H₆O₄)(C₉H₈N₆)]·CH₃OH}_n, each Zn^II ion is five‐coordinated by four O atoms from four glutarate ligands and by one N atom from a 1‐[(1H‐benzimidazol‐2‐yl)methyl]‐1H‐tetrazole (bimt) ligand, leading to a slightly distorted square‐pyramidal coordination environment. Two Zn^II ions are linked by four bridging glutarate carboxylate groups to generate a dinuclear [Zn₂(CO₂)₄] paddle‐wheel unit. The dinuclear units are further connected into a one‐dimensional chain via the glutarate ligands. The bimt ligands coordinate to the Zn^II ions in a monodentate mode and are pendant on both sides of the main chain. In the crystal, the chains are linked by O—H...O and N—H...O hydrogen bonds into a two‐dimensional layered structure. Adjacent layers are further packed into a three‐dimensional network through van der Waals forces. A thermogravimetric analysis was carried out and the photoluminescent behaviour of the polymer was investigated.     

Extension of the chain‐end,free‐volume theory for predicting glass temperature as a function of conversion in hyperbranched polymers obtained through one‐pot approaches

Compared with linear polymers, more factors may affect the glass‐transition temperature (T_g) of a hyperbranched structure, for instance, the contents of end groups, the chemical properties of end groups, branching junctions, and the compactness of a hyperbranched structure. T_g's decrease with increasing content of end‐group free volumes, whereas they increase with increasing polarity of end groups, junction density, or compactness of a hyperbranched structure. However, end‐group free volumes are often a prevailing factor according to the literature. In this work, chain‐end, free‐volume theory was extended for predicting the relations of T_g to conversion (X) and molecular weight (M) in hyperbranched polymers obtained through one‐pot approaches of either polycondensation or self‐condensing vinyl polymerization. The theoretical relations of polymerization degrees to monomer conversions in developing processes of hyperbranched structures reported in the literature were applied in the extended model, and some interesting results were obtained. T_g's of hyperbranched polymers showed a nonlinear relation to reciprocal molecular weight, which differed from the linear relation observed in linear polymers. T_g values decreased with increasing molecular weight in the low‐molecular‐weight range; however, they increased with increasing molecular weight in the high‐molecular‐weight range. T_g values decreased with increasing log M and then turned to a constant value in the high‐molecular‐weight range. The plot of T_g versus 1/M or log M for hyperbranched polymers may exhibit intersecting straight‐line behaviors. The intersection or transition does not result from entanglements that account for such intersections in linear polymers but from a nonlinear feature in hyperbranched polymers according to chain‐end, free‐volume theory. However, the conclusions obtained in this work cannot be extended to dendrimers because after the third generation, the end‐group extents of a dendrimer decrease with molecular weight. Thus, it is very possible for a dendrimer that T_g increases with 1/M before the third generation; however, it decreases with 1/M after the third generation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1235–1242, 2004     

Matrix‐assisted laser ablation production of gold cluster ions from Au‐coated photonic crystals

A new strategy was explored to generate pure gold cluster ions, Au_n^+/?, from gold films deposited on solid substrates via a matrix‐assisted laser ablation technique. The gold films deposited on SiO₂‐particle‐assembled photonic crystals were demonstrated to be the most ideal compared with the films deposited on various glass slides. Dropped with a matrix of 2‐(4‐hydroxyphenylazo) benzoic acid and bombarded by nitrogen pulse laser (355 nm), they could release a series of Au_n⁺ with n more than 110 or Au_n^? with n more than 60 according to the data obtained by inline time‐of‐flight mass spectrometry. The gold‐deposited photonic crystal substrates could be stored at room temperature for at least 6 months. The method is hence steady and convenient in use. Copyright © 2012 John Wiley & Sons, Ltd.