- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Fabrication of Large Single Crystals for Pt-Based Linear Polymers with Controlled-Release and Photoactuator Performance
摘要： Preparation of large single crystals for linear polymers that are amenable to X-ray analysis is very challenging in polymer science. Herein, we employed a coordination driven self-assembly strategy to secure appropriate head-to-tail alignment of anthracene moieties, and for the first time obtained large-sized Pt-based linear polymer crystals through a [4+4] cycloaddition of anthracene in a single-crystal to single-crystal fashion. Using X-ray diffraction analysis to precisely determine polymer crystal structure, we revealed that both the polymerisation and depolymerisation steps proceed via a stable intermediate. Taking advantage of the temperature-dependent slow depolymerization, the afforded Pt-based linear polymer showed potential as a sustained release anticancer drug platform. Furthermore, utilizing the reversible contraction effect of unit-cell volume upon irradiation or heating, the stimuli-responsive crystals were hybridized with polyvinylidene fluoride to obtain a ‘smart material’ with outstanding photoactuator performance. This work not only provides a new approach to prepare metal-containing linear polymer crystals, but also broadens their potential applications towards drug controlled-release and actuator functions.
关键词： Actuator,Sustained release,Topochemical polymerization,Polymer crystals,Linear polymer
更新于2025-09-19 17:13:59
-
Polythioethers with Controlled ?±,??a??End Groups Prepared by Visible Light Induced Thiola??Ene Click Polymerization of Dithiol and Divinyl Ether with 4a??( <i>N</i> , <i>N</i> a??diphenylamino)benzaldehyde as Organocatalyst
摘要： This study reports a step-growth click-polymerization of 1,4-benzenedimethane (BDMT) and diethylene glycol divinyl ether (DEGVE) with 4-(N,N-diphenylamino)-benzaldehyde (DPAB) as a photoredox catalyst under irradiation of visible light. DPAB exhibits a strong UV–vis absorption at 350 nm and a strong fluorescence emission at 480 nm in anisole. There is a strong fluorescence quenching between BDMT and DPAB. The molecular weight of the polythiolether can be controlled by reaction time and monomer feed ratios. More importantly, α,ω-dithiol and α,ω-divinyl telechelic polythiolether oligomers are successfully synthesized by simply changing the molar ratios of BDMT to DEGVE. 1H NMR and MALDI-TOF MS spectra demonstrate that the oligomers have high end group fidelity. In addition, strong fluorescence is observed when the α,ω-dithiol terminated polythiolether adds with N-(1-pyrenyl) maleimide, indicating that the as-prepared polythiolether bears reactive thiol end groups. Furthermore, high molecular weight polythiolether are prepared by chain extension with reactive polythiolether oligomers as macro-monomers. For example, α,ω-divinyl oligomer (Mn = 2000 g mol?1) could further react with α,ω-dithiol oligomer (Mn = 2400 g mol?1) to form high molecular weight polythiolether (Mn = 6000 g mol?1).
关键词： metal-free catalysts,thiol–ene click polymerization,photoredox catalysts,telechelic polymers,photopolymerization
更新于2025-09-19 17:13:59
-
Pressure-Induced Dimerization of C60 at Room Temperature as Revealed by an In Situ Spectroscopy Study Using an Infrared Laser
摘要： Using in situ high-pressure Raman spectroscopy and X-ray di?raction, the polymerization and structure evaluation of C60 were studied up to 16 GPa at room temperature. The use of an 830 nm laser successfully eliminated the photo-polymerization of C60, which has interfered with the pressure e?ect in previous studies when a laser with a shorter wavelength was used as excitation. It was found that face-centered cubic (fcc) structured C60 transformed into simple cubic (sc) C60 due to the hint of free rotation for the C60 at 0.3 GPa. The pressure-induced dimerization of C60 was found to occur at about 3.2 GPa at room temperature. Our results suggest the bene?t and importance of the choice of the infrared laser as the excitation laser.
关键词： fullerenes,pressure-induced,infrared laser,polymerization,Raman
更新于2025-09-19 17:13:59
-
A Versatile 3D and 4D Printing System through Photocontrolled RAFT Polymerization
摘要： Reversible addition-fragmentation chain-transfer (RAFT) polymerization is a valuable tool for synthesizing macromolecules with controlled topologies and diverse chemical functionalities. However, the application of RAFT polymerization to additive-manufacturing processes has been prevented due to the slow polymerization rates of typical systems. In this work, we developed a rapid visible light mediated RAFT polymerization process and applied it to a 3D printing system. The photosensitive resins contained a metal-free dye (erythrosin B) in conjunction with a tertiary amine co-catalyst (triethanolamine) and a trithiocarbonate RAFT agent (2-(butylthiocarbonothioylthio) propanoic acid) to afford polymerization without prior deoxygenation. The reaction components are non-toxic, metal free and environmentally friendly (water based photosensitive resin), which tailors these systems toward the fabrication of biomaterials. Following optimization of the resin formulation by varying the ratio of photocatalyst and tertiary amine, a variety of 3D printing conditions were investigated to prepare functional materials using green light (λmax = 525 nm, I0 = 0.32 mW/cm2). Furthermore, the mechanical properties of these 3D printed materials were tested under different conditions. Interestingly, the concentration of trithiocarbonate impacted the mechanical properties and the performance of these materials. Remarkably, the use of a photoinduced polymerization process provided facile spatial control over the network structure by varying the light dose to each layer of the 3D printed material; using this strategy, a 4D printing process was demonstrated via 3D printing and subsequent swelling and dehydration induced actuation. Furthermore, the trithiocarbonate species incorporated in the polymer networks were able to be reactivated after the initial 3D printing process, which enabled post functionalization of the printed materials via secondary photopolymerization processes. This RAFT-mediated 3D and 4D printing process should provide access to a range of new functional and stimuli-responsive materials.
关键词： Functional Materials,Photopolymerization,3D printing,4D printing,RAFT polymerization
更新于2025-09-19 17:13:59
-
A Versatile 3D and 4D Printing System through Photocontrolled RAFT Polymerization
摘要： Reversible addition-fragmentation chain-transfer (RAFT) polymerization is a valuable tool for synthesizing macromolecules with controlled topologies and diverse chemical functionalities. However, the application of RAFT polymerization to additive-manufacturing processes has been prevented due to the slow polymerization rates of typical systems. In this work, we developed a rapid visible light mediated RAFT polymerization process and applied it to a 3D printing system. The photosensitive resins contained a metal-free dye (erythrosin B) in conjunction with a tertiary amine co-catalyst (triethanolamine) and a trithiocarbonate RAFT agent (2-(butylthiocarbonothioylthio) propanoic acid) to afford polymerization without prior deoxygenation. The reaction components are non-toxic, metal free and environmentally friendly (water based photosensitive resin), which tailors these systems toward the fabrication of biomaterials. Following optimization of the resin formulation by varying the ratio of photocatalyst and tertiary amine, a variety of 3D printing conditions were investigated to prepare functional materials using green light (λmax = 525 nm, I0 = 0.32 mW/cm2). Furthermore, the mechanical properties of these 3D printed materials were tested under different conditions. Interestingly, the concentration of trithiocarbonate impacted the mechanical properties and the performance of these materials. Remarkably, the use of a photoinduced polymerization process provided facile spatial control over the network structure by varying the light dose to each layer of the 3D printed material; using this strategy, a 4D printing process was demonstrated via 3D printing and subsequent swelling and dehydration induced actuation. Furthermore, the trithiocarbonate species incorporated in the polymer networks were able to be reactivated after the initial 3D printing process, which enabled post functionalization of the printed materials via secondary photopolymerization processes. This RAFT-mediated 3D and 4D printing process should provide access to a range of new functional and stimuli-responsive materials.
关键词： Functional Materials,Photopolymerization,3D printing,4D printing,RAFT polymerization
更新于2025-09-19 17:13:59
-
Reverse micelle facilitated synthesis of nanostructured polyaniline as the counter electrode materials in dye-sensitized solar cells
摘要： We report a reverse-micelle emulsion polymerization of nanostructured PANI using a nonionic surfactant Polyglyceryl-2-Dipolyhydroxystearate (PGPH) at various concentrations from 2% to 6% (v/v). SEM images show that the obtained morphologies are irregular agglomerates at low PGPH concentration and relatively regular granules at high PGPH concentration. FTIR and Raman spectra show that the synthesized PANI is in the form of Emeraldine salt (PANI ES) with electrical conductivity around 10?3 S cm?1. Photovoltaic current-voltage (J-V) measurements show the highest power conversion efficiency is achieved at 1.71% at 6% (v/v) of PGPH.
关键词： dye-sensitized solar cell,Counter-electrode materials,nanostructured polyaniline,emulsion polymerization,reverse micelle,polyglyceryl-2-dipolyhydroxystearate
更新于2025-09-19 17:13:59
-
A Facile and Versatile Synthesis of End-Functionalized Poly(phenylacetylene)s: A Multicomponent Catalytic System for Well-Controlled Living Polymerization of Phenylacetylenes
摘要： A rhodium-based multicomponent catalytic system for well-controlled living polymerization of phenylacetylenes has been developed. The catalytic system is composed of easily available and bench-stable [Rh(nbd)Cl]2, aryl boronic acid derivatives, diphenylacetylene, 50% aq KOH, and PPh3. This system offers a method for facile and versatile synthesis of various end-functionalized cis-stereoregular poly(phenylacetylene)s because components from aryl boronic acids and diphenylacetylene were introduced to the initiating end of the polymers. The polymerization reaction shows a typical living nature with a high initiation efficiency, and the molecular weight of the resulting poly(phenylacetylene)s can be easily controlled with very narrow molecular weight distributions (Mw/Mn = 1.02–1.09). The experimental facts suggest that the present catalytic system has the higher polymerization activity than the polymerization activities of other rhodium-based catalytic systems previously reported.
关键词： Living polymerization,Phenylacetylenes,Rhodium,Polymers,Boronic acids
更新于2025-09-19 17:13:59
-
Come to light: detailed analysis of thermally treated Phenyl modified Carbon Nitride Polymorphs for bright phosphors in lighting applications
摘要： Carbon Nitride and its polymorphs have recently gained large interests for their huge properties and applications in different fields, from lighting to photocatalysis. Further, several attempts were recently devoted to tune and control its optical and electrical properties. In this report we analyze phenyl modified Carbon Nitride structures obtained by simple thermal polymerization at different temperatures (250 to 400 °C) of the starting precursor: 2,4-diamino-6-phenyl-1,3,5-triazine. A multi-technique experimental data (XRD patterns, Raman, TGA and DTG, steady- time and time resolved Luminescence, Photoluminescence Excitation spectra, Reflectivity spectra) was applied to analyze the relationship between structural and optical properties and to give more insight on the effect of synthesis procedure on the final polymer. The optical properties evidenced an interesting shift towards the visible region of the absorption spectrum of the phenyl modified g-C3N4 polymer that, associated with the high optical quantum yield (about 60%) and to a broad emission in the green-red spectral region, makes the samples very suitable for lighting applications. Indeed, we report a first prototype of white LED emission by assembly of a commercial blue LED and the Phenyl modified g-C3N4 powders as phosphor, verifying the structural and optical stability over about 10000 working hours.
关键词： Thermal polymerization,Optical properties,Polymorphs,Carbon Nitride,White LED,Lighting applications
更新于2025-09-19 17:13:59
-
Barbier Hyperbranching Polymerization-Induced Emission toward Facile Fabrication of White LED and Light Harvesting Film
摘要： Luminescent polymers are generally constructed through polymerization of luminescent moieties. Polymerization itself however is mainly used for constructing polymer main chain and the importance of polymerization on luminescence has yet to be explored. Here, we demonstrate a polymerization-induced emission strategy producing luminescent polymers by introducing Barbier reaction to hyperbranching polymerization, which allows luminescent properties to be easily tuned from the traditional type to an aggregation-induced emission type by simply adjusting the monomer structure and the polymerization time. When rotation about the phenyl groups in hyperbranched polytriphenylmethanols (HPTPMs) is hindered, HPTPMs exhibit traditional emission property. When all phenyl groups of HPTPM are rotatable, i.e., p,p’,p’’-HPTPM, it exhibits interesting aggregation-induced emission property with tunable emission colors from blue to yellow, by just adjusting polymerization time. Further applications of aggregation-induced emission type luminescent polymers are illustrated by the facile fabrication of white LED and light harvesting film with an antenna effect greater than 14. This Barbier hyperbranching polymerization-induced emission provides a new strategy for the design of luminescent polymers, and expands the methodology and functionality library of both hyperbranching polymerization and luminescent polymers.
关键词： white LED,luminescent polymers,aggregation-induced emission,polymerization-induced emission,light harvesting film,Barbier hyperbranching polymerization
更新于2025-09-16 10:30:52
-
Properties of indirect composites polymerized with laboratory light-emitting diode units
摘要： This study evaluated the light intensity of light-emitting diode (LED) units and the effects of five laboratory polymerization units on hardness and flexural strength. Two indirect composite materials (Cesead N and Solidex Hardura) were polymerized with five units (α-Light II, Hyper LII, LED Cure Master, Twinkle LED, and α-Light V). The light intensity of the devices was measured with a spectroradiometer. After light exposure, Knoop hardness number, flexural strength, and elastic modulus were determined. Evaluation of light intensity, using a wavelength range of 400 to 500 nm, revealed that the α-Light V and Hyper LII units had the highest light intensity. For the top surface of the two composites, the Knoop hardness number was significantly higher for the α-Light V and Hyper LII. For the two composite materials, flexural strength did not differ among the five polymerizing units. The present results indicate that the Cesead N and Solidex Hardura composites can be adequately polymerized with laboratory LED units.
关键词： microhardness,light source,light emitting diode,indirect composite,laboratory light polymerization
更新于2025-09-16 10:30:52