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- 2019
- fan-in/out devices
- polymer optical waveguide
- the Mosquito method
- space division multiplexing
- Optoelectronic Information Science and Engineering
- Keio University
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Versatile Processing of Metal-Organic Framework-Fluoropolymer Composite Inks with Chemical Resistance and Sensor Applications
摘要： We report a new class of MOF inks with a water-repellent, photocurable fluoropolymer (PFPE) having up to 90 wt% MOF loading. These MOF inks enable to process various MOFs through spray coating, pen writing, stencil printing, and moulding at room temperature. Upon UV-curing, the hydrophobic PFPE matrix efficiently blocks water permeation but allows accessibility of chemicals into MOF pores, thereby freeing the MOF to perform its unique function. Moreover, by introducing functional MOFs we successfully demonstrated a water-tolerant chemosensor for a class of aromatic pollutants in water and a chemical-resistant thermosensor for visualizing temperature image. This approach would open up innumerable opportunities for those MOFs that are otherwise dormant.
关键词： MOF-polymer composite,Chemosensor,MOF processing,Thermosensor,Metal-Organic Framework,Chemical resistance
更新于2025-09-23 15:23:52
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A photo-switchable supramolecular hyperbranched polymer with aggregation-induced emission based on host-guest interaction
摘要： In this work, we report a simple strategy by mixing a coumarin appended tetraphenylethylene derivative (TPEC) and γ-cydodextrin(γ-CD) in aqueous solution, based on the host-guest interaction between TPEC and γ-CD to construct a dual-modality supramolecular hyperbranched polymer. The host-guest interaction between γ-CD and TPEC efficiently restricted the intramolecular rotation and the non-radiative relaxation channel, minimizing energy loss, thereby resulting in the strong emission of TPEC in dilute solution. Moreover, we achieved the conversion between non-covalent supramolecular polymers and its corresponding covalent supramolecular hyperbranched polymers under the irradiation of UV light, which can be reversibly controlled through the irradiation at the wavelengths of 254 nm and 365 nm. Furthermore, both non-covalent supramolecular hyperbranched polymers and covalent supramolecular hyperbranched polymers can self-assemble into spherical structures. This methodology provides a new idea for exploring a new type of supramolecular hyperbranched polymers with aggregation-induced emission.
关键词： supramolecular polymer,reversible,host-guest interaction,photo-switchable,dual-modality
更新于2025-09-23 15:23:52
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Dose distribution verification in high-dose-rate brachytherapy using a highly sensitive normoxic N-vinylpyrrolidone polymer gel dosimeter
摘要： Rapid technological advances in high-dose-rate brachytherapy have led to a requirement for greater accuracy in treatment planning system calculations and in the verification of dose distributions. In high-dose-rate brachytherapy, it is important to measure the dose distribution in the low-dose region at a position away from the source in addition to the high-dose range in the proximity of the source. The aim of this study was to investigate the accuracy of a treatment plan designed for prostate cancer in the low-dose range using a normoxic N-vinylpyrrolidone-based polymer gel (VIPET gel) dosimeter containing inorganic salt as a sensitizer (iVIPET). The dose response was evaluated on the basis of the transverse relaxation rate (R2) measured by magnetic resonance scanning. In the verification of the treatment plan, gamma analysis showed that the dose distributions obtained from the polymer gel dosimeter were in good agreement with those calculated by the treatment planning system. The gamma passing rate according to the 2%/2 mm criterion was 97.9%. The iVIPET gel dosimeter provided better accuracy for low doses than the normal VIPET gel dosimeter, demonstrating the potential to be a useful tool for quality assurance of the dose distribution delivered by high-dose-rate brachytherapy.
关键词： Iridium-192,MRI,High-dose-rate brachytherapy,Polymer gel dosimeter
更新于2025-09-23 15:23:52
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Electrochemiluminescence sensor based on upconversion nanoparticles and oligoaniline-crosslinked gold nanoparticles imprinting recognition sites for the determination of dopamine
摘要： For the determination of dopamine (DA) in serum samples, a quenching-type electrochemiluminescence sensor was constructed in this study. Upconversion nanoparticles (UCNPs) enhanced by covalent organic frameworks (COFs)-based hybrid and oligoaniline-crosslinked gold nanoparticles (AuNPs) imprinting recognition sites were introduced in electrochemiluminescence (ECL) system at first time. The porous COFs-based hybrid with large specific surface area was modified on the electrode firstly to hold more UCNPs and imprinting recognition sites. AuNPs, here, was employed in developed sensor for two objectives: 1) AuNPs on COFs-based hybrid enabled the hybrid to tunnel the electrons, which helped to improve the ECL intensity; 2) AuNPs-based thioaniline units (PATP@AuNPs) electropolymerized on the electrode in the presence of template to form oligoaniline-crosslinked AuNPs matrix. Then the exclusion of template from matrix yielded molecularly three-dimensional imprinted contours with conductivity, conducive to specific recognition and further amplify the ECL. The double recognition mode in this work involves the recognition effect of imprinted contours and quenching effect of o-benzoquinone species. The quantum chemical calculation was performed to analyzing the possible recognition and binding mechanisms of molecularly three-dimensional imprinted contours. The results showed imprinted contours could bind the target by complementary spatial cavities and weak interactions. The proposed approach yields a wide detection range (10-14-10-6 M), low limit of detection (LOD=2×10-15 M) and acceptable recoveries (93.25%-112.97%) in rat serum sample, demonstrating that the developed method holds great promise to be applied to DA detection in practical samples.
关键词： Electroconductibility molecular imprinting polymer,Covalent organic frameworks,Oligoaniline-crosslinked gold nanoparticles,Dopamine,Electrochemiluminescence
更新于2025-09-23 15:23:52
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Flexible all-organic photorefractive devices
摘要： The objective of the present study is to demonstrate and evaluate the photorefractive (PR) performance of an all-organic PR device with a self-assembled monolayer (SAM)-modified organic conductive electrode of PEDOT:PSS coated on polyethylene terephthalate (PET). The PR composite consisted of a triphenylamine-based photoconductive polymer: poly(4-(diphenylamino)benzylacrylate) (PDAA), triphenylamine photoconductive plasticizer: (4-(diphenylamino)phenyl)methanol (TPAOH), nonlinear optical dye based on aminocyanostyrene: (4-asacycloheptylbenzylidenemalononitrile) (7-DCST), and soluble fullerene: [6, 6]-phenyl C61 butyric acid-methyl ester (PCBM). For comparison with the all-organic PR device, the PR performances using PET/ITO, glass/ITO, and glass/PEDOT:PSS substrates were also evaluated. The PR performance at an applied electric field of 40 V μm-1: diffraction efficiency and the response time of the PR device using PET/PEDOT:PSS-SAM substrate were 21.9%, and 390 ms, respectively. As a result of repeating bending test on this all-organic PR device, we found that the flexible PR device with PET/PEDOT:PSS-SAM substrate had a potential to withstand bending 10,000 times and revealed that the change in the haze value strongly influenced the degradation of PR performance.
关键词： All-organic,Photorefractive polymer,ITO-free device,PET substrate,PEDOT:PSS,Flexible
更新于2025-09-23 15:23:52
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A new insight for photocatalytic hydrogen production by a Cu/Ni based cyanide bridged polymer as a co-catalyst on titania support in glycerol water mixture
摘要： A two dimensional Cu/Ni based coordination polymer (CP-1) $0.7(C2H6O2)$1.6(H2O) (4,4?-dipy ? 1,3-di(4-pyridyl)propane) has been demonstrated as a potential co-catalyst on TiO2 support for hydrogen evolution under UV light. CP-1/TiO2 composite exhibits considerable hydrogen production in comparison with the pristine CP-1 and TiO2 (P25), highlighting that the photocatalytic performance is significantly related with the good separation of photo generated e-/h+ pairs. Different wt. % (2.5, 5 and 7.5%) of CP-1 in CP-1/TiO2 composites were tested for photocatalytic hydrogen production in 5 vol % glycerol/water mixture. The 5 wt % CP-1/TiO2 composite displayed the greatest hydrogen production of 9.2 mmol h-1 g-1. The concealed mechanism is divulged on the behalf of results obtained by cyclic voltammetry, photoluminescence and diffused reflectance/UV-visible studies which demonstrate that upon irradiation of UV light, electrons transfer from TiO2 conduction band to CP-1. CP-1 not only grabs the conduction band electrons of titania but also performes as a co-catalyst to reduce the protons into hydrogen. These results are anticipated to direct the forthcoming advancement in creating proficient, cheap semiconductor photocatalysts for solar hydrogen production.
关键词： Hydrogen,Coordination polymer,Co-catalyst,Photocatalyst,Titanium dioxide
更新于2025-09-23 15:23:52
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Photoresponsive Circular Supramolecular Polymers: Topological Trap and Photoinduced Ring-opening Elongation
摘要： Topological features of one-dimensional macromolecular chains govern the properties and functionality of natural and synthetic polymers. To address this issue in supramolecular polymers, we have synthesized two topologically distinct supramolecular polymers with intrinsic curvature, i.e., circular and helically folded nanofibers, from azobenzene-functionalized supramolecular rosettes. When a mixture of circular and helically folded nanofibers was exposed to UV light, a selective unfolding of the latter open-ended supramolecular polymers was observed as a result of the curvature-impairing internal force produced by the trans-to-cis photoisomerization of the azobenzene. This distinct sensitivity suggests that the topological features of supramolecular polymers define their mechanical stability. Furthermore, the exposure of circular supramolecular polymers in more polar media to UV irradiation resulted in a ring-opening followed by a chain elongation, demonstrating that the circular supramolecular polymer can work as a topological kinetic trap.
关键词： topology,ring opening,azobenzene,supramolecular polymer,photoisomerization
更新于2025-09-23 15:23:52
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High-density Azobenzene Side Chain Polymer Brush for Azimuthal and Zenithal Orientation Photoswitching of Nematic Liquid Crystal
摘要： The azimuthal and zenithal orientation switching of nematic liquid crystals (NLCs) can be performed by photoresponsive azobenzene alignment layers called command surfaces. Such photoresponsive layers have been prepared by molecular assembly methods or spincast of polymer materials. This work reports on the photo-switching orientation behavior of NLC on a high-density brush of an azobenzene-containing side chain liquid crystalline polymer. On the high-density polymer brush surface, the zenithal homeotropic/planar photoalignment switching modes triggered by UV/visible light irradiation are reversed from those observed for traditional command surface systems, reflecting the azobenzene side chain orientation directing parallel with the substrate surface. Because the thermally stable trans-azobenzene provides the in-plane orientation of NLC, irradiation with linearly polarized visible light readily switches the azimuthal direction to an arbitrary direction, and the resulting orientation is retained persistently. This paper discusses the features of the architecture of high-density polymer brush as the command surface for NLC orientation.
关键词： azobenzene,photoalignment,photoresponsive surface,nematic liquid crystal,polymer brush
更新于2025-09-23 15:23:52
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Engineering organic electrochemical transistor (OECT) to be sensitive cell-based biosensor through tuning of channel area
摘要： The barrier integrity of epithelial tissue is crucial to many physiological functions in multicellular organisms. Hence, several scientific techniques, such as epithelial voltohmmeter (EVOM) and electric cell-substrate impedance sensing (ECIS), were developed to assess barrier function for in vitro assays. Organic electrochemical transistor (OECT), in particular, outperforms many biosensors because of its multiple advantages such as high transconductance, mixed ionic-electronic conductivity and high biocompatibility. Despite its extensive application in cell impedance sensing, little was reported on how its geometrical dimensions would affect the device performance and quality of cell-based measurement. In this work, OECTs in different dimensions were fabricated and characterized. Specifically investigated were their time and frequency responses towards the presence of epithelial cells (i.e. tightly packed colorectal adenocarcinoma cell line caco-2 and a novel leaky nasopharyngeal carcinoma cell line NPC43). Results show that the sensitivity of cell-based measurement is closely related to the impedance of the whole cell-OECT system. The performance of cell-based sensor would be affected by the tightness of target cell and can be tuned by controlling the active area of OECT.
关键词： Conducting polymer,Frequency response,Biosensor,Impedance spectroscopy,Transepithelial electrical resistance,Organic electrochemical transistor
更新于2025-09-23 15:23:52
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Coordination Polymers Based on Organic–Inorganic Hybrid Rigid Rod Comprising a Backbone of Anderson-Evans POMs
摘要： To construct polyoxometalates coordination polymers (PCPs), we prepared two pyridine ligand functionalized Anderson POMs: (TBA)3[MnMo6O18((OCH2)3CN=CH-4-Py)2]·DMF ((TBA)3POM-1, TBA = tetrabutyl ammonium, Py = pyridine) and (TBA)3[MnMo6O18((OCH2)3CN=CH-3-Py)2] ((TBA)3POM-2) via the post-functionalization of (TBA)3[MnMo6O18((OCH2)3CNH2)2] (Anderson-NH2) by 4-pyridinealdehyde and 3-pyridinealdehyde, respectively. They are characterized using X-ray single crystal diffraction, MALDI-TOF MS, ESI MS, FT-IR, UV-Vis and 1H NMR . The self-assembly of (TBA)3POM-1 and [Cu(PPh3)2(CH3CN)2]ClO4 (CuP2) in the mole ratios of 1 : 2 and 1 : 3, both gave the same 1D double chain with the molecular formula of (NBu4)n{[Cu(PPh3)2]2(POM-1)}n (7.5DMF)n (1). On the contrary, the self-assembly of (TBA)3POM-2 and CuP2 in the mole ratio of 1:2 yields a 2D coordination polymer of (TBA)n{[Cu(PPh3)2]2(POM-2)}n·(2DMF)n (2), while that self-assembly process in the mole ratio of 1:3 results in different 2D coordination polymer of {[Cu(PPh3)2]3(POM-2)·(CH3CN)}n·(5CH3CN)n (3). Compounds 1-3 can keep their skeleton structures below 230oC. They exhibit intense green emission (496nm for 1; 537nm for 2; 530nm for 3) by ultra-violet irradiation (327nm for 1; 303nm for 2; 331nm for 3), which can be tentatively ascribed as ILCT with metal perturbation.
关键词： Luminescence,Polyoxometalates,Pyridine,Coordination Polymer,Copper (I)
更新于2025-09-23 15:23:52