- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- fan-in/out devices
- polymer optical waveguide
- the Mosquito method
- space division multiplexing
- Optoelectronic Information Science and Engineering
- Keio University
-
Photodegradable MEH-PPV in a natural rubber matrix: Toward a biocompatible colorimetric film for real-time light dosimetry
摘要： This paper reports an interesting strategy of incorporating a photodegradable polymeric luminophore, the poly [2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] - OC10C6-PPV (MEH-PPV), in an inert natural rubber (Hevea brasiliensisis) - C5H8 (NR) matrix for monitoring and recording the radiation dose administered to patients under phototherapy, particularly in the treatment for jaundice newborns. A time-trend spectro?uorimetric study has been carried out to characterize the luminescent changes of the MEH-PPV/NR luminophore system upon photodegradation by realistic conditions of phototherapy treatment, and the dependence between color and dose was used to determine the dose-response relationships of this color ?lm dosimeter. Cytotoxicity tests (CHO-K1 cell line) have also been conducted on extracts of the OC10C6-PPV/C5H8 before and after photolysis. The experimental results reported here highlight the potential application of photodegradable polymer/natural rubber as a biocompatible skin-mountable patch to monitor light exposure to improve patient care in phototherapy, photodynamic, lasers and radiation therapies.
关键词： Medical-devices,Dosimeter,Printable device,Photooxidation,Organic device,Semiconducting polymer,Radiation oncology
更新于2025-11-14 15:18:02
-
Improvement of Sensing Performance of Impedancemetric C2H2 Sensor Using SmFeO3 Thin-Films Prepared by a Polymer Precursor Method
摘要： A sensitive an impedancemetric acetylene (C2H2) gas sensor device could be fabricated by using perovskite-type SmFeO3 thin-film as a sensor material. The uniform SmFeO3 thin-films were prepared by spin-coating and focusing on the effects of polymer precursor solutions. The prepared precursors and thin-films were characterized by means of thermal analysis, Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction analysis, scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that particle growth and increase in homogeneity of the prepared thin-film could be accelerated by the addition of acetyl acetone (AcAc) as a coordination agent in the polymer precursor solution. Moreover, the highly crystallized thin-film-based sensor showed good response properties and stabilities to a low C2H2 concentration between 0.5 and 2.0 ppm.
关键词： polymer precursor,acetyl acetone,thin-film,gas sensor,acetylene,perovskite-type oxide,AC impedance
更新于2025-11-14 15:15:56
-
Preparation and immobilization of zinc sulfide (ZnS) nanoparticles on polyvinylidene fluoride pellets for photocatalytic degradation of methylene blue in wastewater
摘要： ZnS nanoparticles with 90 nm diameter were synthesized by low-temperature method and immobilized onto the surface of polyvinylidene fluoride (PVDF) pellets prepared by phase inversion method. Results by FTIR and X-ray photoelectron spectroscopy revealed that the ZnS nanoparticles were immobilized tightly on the PVDF surface without their release and losing photocatalytic activity. The UV-absorption spectra showed that the PVDF matrix had no adverse effect on the optical properties of ZnS nanoparticles. Due to large size (5 mm) and excellent mechanical stability, the PVDF-ZnS pellets could be easily dispersed in the photocatalytic reactor treating methylene blue solution. The removal efficiency of the methylene blue with the PVDF-ZnS pellets was higher (more than 95%) than that observed by the control PVDF pellets or ZnS nanoparticles tested. No change in the removal efficiency was observed as the PVDF-ZnS pellets were reused by performing photocatalytic tests at the same experimental conditions repeatedly.
关键词： Reusability,Polymer carrier,Zinc sulfide,Immobilization,Phase inversion,Photocatalytic degradation
更新于2025-11-14 15:14:40
-
One-Dimensional Mercury Halide Coordination Polymers Based on A Semi-Rigid N-Donor Ligand: Reversible Structural Transformation
摘要： Four one-dimensional (1D) mercury(II) halide coordination polymers have been synthesized by using a semi-rigid N-donor ligand, 2,2′-(1,4-phenylene)-bis(N-(pyridin-3-yl)acetamide) (1,4-pbpa). While [Hg(1,4-pbpa)Cl2·CH3OH]n, 1, forms a sinusoidal chain, the complexes [Hg(1,4-pbpa)X2]n (X = Cl, 2; Br, 3; I, 4) are helical. The sinusoidal 1 undergoes reversible structural transformation with helical 2 upon removal and uptake of CH3OH, which was accompanied with the conformation adjustment of the 1,4-pbpa ligand from trans anti-anti to trans syn-anti. Pyridyl ring rotation of the 1,4-pbpa ligand that results in the change of the ligand conformation is proposed for the initiation of the structural transformation.
关键词： mercury halide,structural transformation,bis-pyridyl-bis-amide,coordination polymer
更新于2025-11-14 15:13:28
-
Effects of fluorination and thermal annealing on charge recombination processes in polymer bulk-heterojunction solar cells
摘要： We investigate the effect of fluorination on the photovoltaic properties of an alternating conjugated polymer composed of 4,8-di-2-thienylbenzo[1,2-b:4,5-b0]dithiophene and 4,7-bis([2,20-bithiophen]-5-yl)-benzo-2-1-3-thiadiazole (4TBT) units in bulk-heterojunction solar cells. The unsubstituted and fluorinated polymers afford very similar open-circuit voltages and fill factor values, but the fluorinated polymer performed better due to enhanced aggregation which provides a higher photocurrent. The photovoltaic performance of both materials improved upon thermal annealing at 150–200 °C as a result of a significantly increased fill factor and open-circuit voltage, counteracted by a slight loss in photocurrent. Detailed studies of the morphology, light intensity dependence, external quantum efficiency and electroluminescence allowed the exploration of the effects of fluorination and thermal annealing on the charge recombination and the nature of the donor–acceptor interfacial charge transfer states in these films.
关键词： polymer bulk-heterojunction solar cells,thermal annealing,charge recombination,fluorination,photovoltaic properties
更新于2025-10-22 19:40:53
-
Effect of Thionation on the Performance of PNDIT2-Based Polymer Solar Cells
摘要： All-polymer solar cells have gained traction in recent years with solar cell performance of over 11% power conversion efficiency (PCE) recently demonstrated. The n-type polymer PNDIT2, also known as N2200 or P(NDI2OD-T2), has been extensively used for both photovoltaic as well as field-effect transistor applications. When paired with donor materials that have appropriately aligned energy-levels, PNDIT2 has exhibited device efficiencies over 10% PCE, and organic field effect transistors fabricated with PNDIT2 exhibit mobilities over 1 cm2/Vs. Thionation of the NDI moiety, which is the substitution of imide oxygen with sulfur atoms, has been shown to improve the field-effect transistor performance of NDI-based small molecules. Applying this strategy to PNDIT2, we explored the effect that thionation, in a 2S-trans configuration, has on the performance of all-polymer solar cells fabricated with the donor polymer PTB7-Th. Solar cells were fabricated with the original polymer, PNDIT2, as a reference, and an optimized efficiency of 4.85% was achieved. As samples with 100% conversion to 2S-trans configuration could not be produced due to synthetic limitations, batches with increasing ratios of 1S to 2S-trans thionation (15:85, 7:93, and 5:95) were studied. Devices with thionated PNDIT2 exhibited a systematic lowering of photovoltaic parameters with increasing thionation, resulting in device efficiencies of just 0.84%, 0.62%, and 0.42% PCE. The lower performance of the thionated blends is attributed to poor π-π stacking order in the thionated PNDIT2 phase, resulting in lower electron mobilities and finer phase separation. Evidence in support of this conclusion is provided by grazing incidence wide-angle X-ray scattering, transmission electron microscopy, photoluminescence quenching, transient photocurrent analysis, and SCLC measurements.
关键词： π-π stacking,PNDIT2,Thionation,All-polymer solar cells,Power conversion efficiency
更新于2025-10-22 19:40:53
-
Microwave-assisted synthesis of FexZn1?xO nanoparticles for use in MEH-PPV nanocomposites and their application in polymer light-emitting diodes
摘要： A one-step microwave-assisted polyol method was used to fabricate FexZn1?xO (x = 0.01, 0.05, 0.10) nanoparticles. Zinc acetate dihydrate, iron (III) acetylacetonate, oleic acid and diethylene glycol were placed in a Teflon-lined reaction vessel. The reaction mixture was heated up to 250 °C for 15 min in a microwave reactor. The surface modification with oleic acid prevented agglomeration of the nanoparticles. The X-ray diffraction analysis revealed characteristics wurtzite hexagonal structure of ZnO and successful incorporation of the Fe dopant into the host crystal lattice. Doping of ZnO by Fe led to bandgap modification as estimated by Tauc plot. The as-prepared nanopowders were dispersed in toluene and mixed with a poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) polymer to make stable homogenous dispersions. Then, the FexZn1?xO/MEH-PPV nanocomposite thin films were prepared by spin coating and used as thin active layers in polymer light-emitting diodes. The thickness of deposited FexZn1?xO/MEH-PPV film was ca. 30 nm and that of reference neat MEH-PPV film was ca. 25 nm. The electroluminescent spectroscopy study showed that direct blending of MEH-PPV with Fe-doped ZnO nanoparticles is a simple and effective approach to significantly increase the luminance intensity of the diode in comparison to the diode fabricated by neat MEH-PPV.
关键词： Polymer light-emitting diodes,FexZn1?xO nanoparticles,Microwave-assisted synthesis,MEH-PPV nanocomposites
更新于2025-10-22 19:40:53
-
Tin( <scp>ii</scp> ) thiocyanate Sn(NCS) <sub/>2</sub> – a wide band gap coordination polymer semiconductor with a 2D structure
摘要： Semiconductors based on tin(II) show promising hole-transport characteristics due to the 5s electrons that form the valence band. In this paper, we report the synthesis and comprehensive characterization of tin(II) thiocyanate [Sn(NCS)2] and identify it as a novel transparent coordination polymer semiconductor. The single crystal X-ray analysis reveals covalently-bonded 1D polymeric chains that form a 2D structure through Sn–S tetrel bonds. Density functional theory calculations also confirm the importance of the van der Waals interactions between the 2D sheets. Furthermore, we show that the s character of Sn(II) is maintained at the top of the valence band, resulting in dispersed states with a small hole effective mass. The coordination with NCS ligands also leads to a conduction band which is high in energy, giving rise to a wide band gap and excellent transparency in the visible spectrum. This is the first report on the electronic properties of Sn(NCS)2 which highlights the potential of developing new transparent semiconductors based on thiocyanate coordination polymers.
关键词： hole transport,band gap,tin(II) thiocyanate,transparent,semiconductor,coordination polymer
更新于2025-10-22 19:40:53
-
Influence of the intramolecular donor-acceptor distance on the performance of double-cable polymers
摘要： A series of double-cable polymers PFT-C4-PDI, PFT-C6-PDI and PFT-C8-PDI, composed of the poly(fluorene-alt-thiophene) (PFT) backbone, the perylene diimide (PDI) pendants and the length-various (four-, six- and eight-carbon) covalent alkoxy linkers, were presented. The backbone polymer chain created the hole-transporting channel and the inner-chain aggregation of PDI units created the electron-transporting channel, but the aggregation became weaker along with the longer linker, as proven by the UV-Vis absorption and fluorescence quenching. The polymers were non-conducting, but functioned as efficient compatibilizers. The doping of the polymers induced the formation of the bi-continuous networks inside P3HT:PCBM blends, facilitated photo-generated exciton dissociation and charge transporting. PFT-C4-PDI more efficiently increased the absorption coefficient and the charge-carrier mobility of the P3HT:PCBM film. The power conversation efficiency (PCE) of the P3HT:PCBM bulk-heterojunction solar cells with 3 wt% PFT-C4-PDI, PFT-C6-PDI and PFT-C8-PDI doping were improved by 16.9%, 9.2% and 8.0%, respectively, relative to the non-doped reference device.
关键词： Structure-property relationships,Energy transfer,Double-cable polymer,Polymer solar cells,Bi-continuous networks
更新于2025-09-23 15:23:52
-
Heat-Assisted Photoacidic Oxidation Method for Tailoring the Surface Chemistry of Polymer Dielectrics for Low-Power Organic Soft Electronics
摘要： The use in low-power soft electronics of the appropriate insulating polymer materials with a high dielectric constant (k) is considered a practical alternative to that of inorganic dielectric materials, which are brittle and have high processing temperatures. However, the polar surfaces of typical high-k polymer insulators are problematic. Further, it is a huge challenge to control their surface properties without damage because of their soft and chemically fragile nature. Here, a heat-assisted photoacidic oxidation method that can be used to effectively oxidize the outermost surfaces of high-k rubbery polymer films without degradation is presented. The oxidized surfaces prepared with the developed method contain large numbers of hydroxyl groups that enable the subsequent growth of dense and ordered self-assembled monolayers (SAMs) consisting of organosilanes. The whole process modifies the surface characteristics of polymer dielectrics effectively. The mechanisms of the oxidation of polymer surfaces and the subsequent SAM growth process are investigated. The resulting surface-tailored rubbery dielectrics exhibit superior electrical characteristics when used in organic transistors. These results demonstrate that this method can be used to realize practical soft organic electronics based on high-k polymer dielectrics.
关键词： self-assembled monolayers,organic semiconductors,polymer gate dielectric,polymer oxidation,surface chemistry
更新于2025-09-23 15:23:52