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Synthesis of water-soluble conjugated polymer, poly(N-3-sulfopropylaniline) and the study of its glucose sensing property
摘要： A water-soluble conjugated polymer, poly(N-3-sulfopropylaniline) (PSPA) with 7–10 controlled repeating units has been synthesized through oxidative polymerization of sulfopropylaniline (SPA) monomer, which is prepared by N-alkylation of aniline using 3-propane sultone. The glass transition temperature (Tg), thermal stability, molecular weight and size distribution of the synthesized polymer were investigated by DSC, TGA and MALDI TOFF respectively. The spectral (UV-Vis, PL, NMR, FTIR) analysis has been done to develop a facile colorimetric method to sense glucose (a biomarker of diabetes). The synthesized polymers could detect glucose up to nanomolar (10?9 M), which are 106 fold less than the level of a diabetic patient (4 × 10?3-9 × 10?3 M). It is also observed that the naked eye can sense up to decimolar (10?1 M) level. The polymerization process and the chemistry of colorimetric sensing are explained through spectral and cyclic voltammetry analysis. The polymerization and the sensing of glucose occurred through the electron transfer dependent color change processes.
关键词： Polymerization,Glucose sensing,Spectroscopy,Thermal analysis
更新于2025-09-23 15:23:52
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Chemical-Electrochemical Sequential Double-Step Polymerization in Liquid Crystal Allows for Imprinting of 3D Molecular Assembly Form Showing Electro-Chiroptical Effect
摘要： Chiroptical polypyrrole (PPy) film was prepared by sequential reaction of chemical oligomerization with FeCl3 and subsequent electrochemical polymerization in a cholesteric liquid crystal (CLC) consisting of 4-cyano-4’penthylbiphenyl (5CB) and cholesteryl oleyl carbonate (COC). Chemical oxidation reaction of pyrrole as a monomer with FeCl3 in the liquid crystal (LC) produces linear shaped pyrrole oligomer. The linear shaped precursor having good affinity with LC molecular can pre-align along the director of the CLC. Subsequent electrochemical polymerization of the precursor in the CLC affords structure transcription from the matrix CLC to the polymer, resulting production of PPy with effective imprinting of the LC order. Surface observations of the PPy film with polarizing optical microscopy (POM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) reveal fingerprint textures of the surface, suggesting occurrence of transcription of the helical structure of the CLC to the polymer films. The PPy film shows electrochromism between -0.7 V and 0.3 V. Furthermore, the circular dichroism (CD) optical absorption spectra indicated that the PPy film exhibits optical activity even though no chiral centers in the molecular structure. The asymmetry of the resultant polymer is derived from 3-D chiral assembly imprinted from the matrix CLC. Therefore, the CD spectra of the PPy film at the oxidized and the reduced states show change in chiroptical activity. This phenomenon can be referred to as an electro-chiroptical effect.
关键词： electrochromic,liquid crystal,electrochemical polymerization,chiroptical,polypyrrole
更新于2025-09-23 15:23:52
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Preparation of graphene oxide with large lateral size and graphene/polyimide hybrid film via in situ “molecular welding” strategy
摘要： In this letter, we report an "ultrasonication-free" direct exfoliation method to obtain graphene oxide with large lateral size (LGO). The average size of LGO sheets is about 50 lm * 50 lm. The g-LGO film shows a superior in-plane thermal conductivity after the graphitization treatment. Furthermore, the in situ "molecular welding", using polyimide (PI) to weld up the GO sheets, is conducted to improve the performance of hybrid thermal conducting film. The thermal conductivity of g-LGO/PI film is 1053.975 ± 8.762 W m-1 K-1, superior to that of the g-LGO film and g-SGO/PI. The direct preparation method to obtain GO with large lateral size, followed by such an in situ "molecular welding" strategy by PI, provides a promising way to fabricate graphene-based film for efficient thermal management.
关键词： Molecular welding,In situ polymerization,Large lateral size,Thermal properties,Carbon material
更新于2025-09-23 15:23:52
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A Continuous Synthesis of Polymethylmethacrylate Using a Microreactor Plant
摘要： We applied a microreactor to the synthesis of polymethylmethacrylate (PMMA) using a laboratory microreactor system with a production volume of 2–3 t per year, which enabled pseudo-continuous feeding by syringe pumps. When using a tube made of stainless steel, the values of the yield, number average molecular weight (Mn), and polydispersity index (PDI) reached 75.2%, 9.4×103, and 1.88, respectively. These results were in good accordance with the reported ones and a product with comparable properties was obtained. Then, we performed a continuous synthesis of PMMA for 8 h using a medium scale microreactor plant with a production volume of 100 t per year, which provided continuous feeding by triple cam driven pumps. When using a tube made of polytetrafluoroethylene (PTFE), it was confirmed that a product was continuously obtained for 8 h, whose yield, Mn, and PDI were on average 66.2%, 8.8×103, and 1.95, respectively. The variation in the yield, Mn, and PDI was within 5.7%, 4.5%, and 1.0%, respectively. For comparison, when using the laboratory microreactor system under the same reaction condition with a tube made of PTFE, the corresponding values of the yield, Mn, and PDI were 66.5%, 8.4×103, and 2.04, respectively. The difference in the results between the above two microreactor systems was 4.8% at a maximum (in Mn). Therefore, the synthesis of PMMA was continuously performed using the medium scale microreactor plant and the comparability of the reaction performance between the above two microreactor systems was ensured.
关键词： Microreactor Plant,Microreactor,Polymethylmethacrylate,Polymerization Reaction
更新于2025-09-23 15:23:52
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Polydopamine-Based Tumor-Targeted Multifunctional Reagents for Computer Tomography/Fluorescence Dual-Mode Bioimaging-Guided Photothermal Therapy
摘要： Development of multifunctional diagnosis and treatment reagents is very meaningful in clinical application. Herein, we developed a polydopamine-based (PDA-based) tumor targeted multifunctional reagent by surface-initiated atom transfer radical polymerization (ATRP) strategy. First, the targeted PDA nanoparticles were prepared via combining with folic acid (FA) and dopamine. Then ATRP technology was used to graft the europium(III) complexes onto PDA surface (defined as FEDA). A series of detections revealed that the FEDA nanoparticles had been successfully prepared and exhibited a bright X-ray computer tomography (CT) and photoluminescence (PL) dual-mode imaging efficiency and an excellent photothermal therapy (PTT) effect in vivo/in vitro.
关键词： europium(III) complexes,polydopamine,dual-mode imaging-guided photothermal therapy,folic acid targeted,atom transfer radical polymerization
更新于2025-09-23 15:23:52
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A Radio-Fluorogenic Polymer-Gel Makes Fixed Fluorescent Images of Complex Radiation Fields
摘要： We review the development and application of an organic polymer-gel capable of producing fixed, three-dimensional fluorescent images of complex radiation fields. The gel consists for more than 99% of γ-ray-polymerized (~15% conversion) tertiary-butyl acrylate (TBA) containing ~100 ppm of a fluorogenic compound, e.g., maleimido-pyrene (MPy). The radio-fluorogenic effect depends on copolymerization of the MPy into growing chains of TBA on radiation-induced polymerization. This converts the maleimido residue, which quenches the pyrene fluorescence, into a succinimido moiety (SPy), which does not. The intensity of the fluorescence is proportional to the yield of free-radicals formed and hence to the local dose deposited. Because the SPy moieties are built into the polymer network, the image is fixed. The method of preparing the gel and imaging the radiation-induced fluorescence are presented and discussed. The effect is illustrated with fluorescent images of the energy deposited in the gel by beams of X-rays, electrons, and protons as well as a radioactive isotope.
关键词： polymer gel dosimetry,radio-fluorogenic co-polymerization,radio-fluorogenic gel,3D dose imaging,proton beam imaging,tertiary-butyl acrylate gel
更新于2025-09-23 15:23:52
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Bio-Inspired Structural Colors based on Linear Ultra-High Molecular Weight Block Copolymers
摘要： Ultra-high molecular weight (UHMW) block copolymers (BCPs) are promising candidates for the fabrication of photonic materials. Here, we demonstrate the synthesis and self-assembly capability of well-defined amphiphilic UHMW BCPs with overall molar masses up to 4432 kg mol-1 obtained via living anionic polymerization. BCP micelles featuring hydrodynamic diameters in the range of the wavelength of the visible light to the near infrared region (300-1143 nm) are used for colloidal crystal formation. By varying the BCP composition brilliant structural colours can be observed. Microphase separation of the UHMW BCPs in the bulk state reveals uniform domains and showing blue to green structural color transitions. Finally, we provide examples of how BCP structural control can be used to generate reversibly switchable solvatochromatic optical sensors.
关键词： morphology,block copolymers,structural colors,self-assembly,anionic polymerization,micellar photonic crystals,photonic materials
更新于2025-09-23 15:23:52
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Controlling Chain Coupling and Single Chain Ligation by Two Colours of Visible Light
摘要： While photochemical synthesis offers access to spatiotemporal reaction control, its potential to selectively address specific reactions by the colour of light is usually limited by ubiquitous spectral absorption overlaps of the reactive groups. Inhere, a new concept is introduced that actively suppresses one ligation reaction by triggering the cycloreversion of the [2+2] cycloaddition of styrylpyrene. Combination of the photoreversible styrylpyrene chemistry with the [4+4] cycloaddition of 9-triazolylanthracene allows to initially induce chain coupling using UV light and to subsequently ligate the formed single chain nanoparticle (SCNP) with a second polymer chain using blue light. Seizing upon the first sequence independent λ-orthogonal reactivity established in here, the same macromolecular architecture was obtained in reverse irradiation sequence, by blue and subsequent violet light irradiation – completely foregoing high energy UV-light.
关键词： Polymer Ligation,Orthogonal Reactions,RAFT polymerization,Photochemistry,Single Chain Nanoparticles
更新于2025-09-23 15:23:52
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Interface Modulation of Core-Shell Structured BaTiO3@polyaniline for Novel Dielectric Materials from Its Nanocomposite with Polyarylene Ether Nitrile
摘要： The core-shell structured polyaniline-functionalized-BaTiO3 (BT@PANI) nanoparticles with controllable shell layer thicknesses are developed via in-situ aniline polymerization technology and characterized in detail. The results prove that the PANI shell layer with the adjustable and controllable thicknesses of 3–10 nm are completely stabilized on the surface of the BaTiO3 core. In addition, the BT@PANI nanoparticles are regarded as the hybrid nanofillers to prepare PEN/BT@PANI nanocomposite films with a PEN matrix. The research results indicate that the surface functionalized nanoparticles facilitate the compatibility and dispersibility of them in the PEN matrix, which improves the properties of the PEN/BT@PANI nanocomposites. Specifically, the PEN/BT@PANI nanocomposites exhibit thermal stability, excellent permittivity-frequency, and dielectric properties-temperature stability. Most importantly, the energy density of nanocomposites is maintained at over 70% at 180 °C compared with that at 25 °C. All these results reveal that a new way to prepare the high-performance PEN-based nanocomposites is established to fabricate an energy storage component in a high temperature environment.
关键词： dielectric properties,in-situ polymerization,nanoparticles,nanocomposites
更新于2025-09-23 15:22:29
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Synthesis of High Performance Cyclic Olefin Polymers (COPs) with Ester Group via Ring-Opening Metathesis Polymerization
摘要： Novel ester group functionalized cyclic olefin polymers (COPs) with high glass transition temperature, high transparency, good mechanical performance and excellent film forming ability have been achieved in this work via efficient ring-opening metathesis copolymerization of exo-1,4,4a,9,9a,10-hexahydro-9,10(1′,2′)-benzeno-l,4-methanoanthracene (HBM) and comonomers (5-norbornene-2-yl methylacetate (NMA), 5-norbornene-2-yl methyl 2-ethylhexanoate (NME) or 5-norbornene-2-yl methyldodecanoate (NMD)) utilizing the Grubbs first generation catalyst, Ru(CHPh)(Cl)2(PCy3)2 (Cy = cyclohexyl, G1), followed by hydrogenation of double bonds in the main chain. The fully hydrogenated copolymers were characterized by nuclear magnetic resonance, FT-IR spectroscopy analysis, gel permeation chromatography, and thermo gravimetric analysis. Differential scanning calorimetry curves showed that the glass transition temperatures (Tg) linearly decreased with the increasing of comonomers content, which was easily controlled by changing feed ratios of HBM and comonomers. Static water contact angles tests indicate that hydrophilicity of copolymers can also be modulated by changing the comonomers incorporation. Additionally, the mechanical performances of copolymers were also investigated.
关键词： dimensional stability,optical materials,COPs (cyclic olefin polymers),ROMP (ring-opening metathesis polymerization),hydrophilicity
更新于2025-09-23 15:22:29