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Seunghyun Jeong Joon Ho Yoon Pankaj Attri In Tae Kim 《Journal of Saudi Chemical Society》2021,25(5):101227
Over the past few years, polymers shown comprehensive utilization in optical devices, solar cells, sensors, and other such devices. However, the efficiency of these devices remains a problem. We have synthesized new thiophene based, lowband gap polymer, poly(2-heptadecyl-4-vinylthieno[3,4-d] [1,3] selenazole) (PHVTS) and investigated the interactions between the PHVTS and ionic liquids (ILs), in this study. We have used imidazolium- and ammonium-family ILs, and studied the interactions using various spectroscopic techniques such UV–visible, FTIR, and confocal Raman spectroscopies. Additionally, we studied surface morphology of the polymer-IL film. Spectroscopic studies show that both families of ILs can interact with the newly synthesized polymer poly(2-heptadecyl-4-vinylthieno[3,4-d] [1,3] selenazole). However, the imidazolium-family Ionic Liquid-polymer (IL-polymer) mixture films show higher conductivities than ammonium-family IL–polymer mixture films. 相似文献
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Supramolecular Phthalocyanine Assemblies for Improved Photoacoustic Imaging and Photothermal Therapy
Xingshu Li Eun‐Yeong Park Youngnam Kang Nahyun Kwon Mengyao Yang Seunghyun Lee Won Jong Kim Chulhong Kim Juyoung Yoon 《Angewandte Chemie (International ed. in English)》2020,59(22):8630-8634
Phototheranostic nanoplatforms are of particular interest for cancer diagnosis and imaging‐guided therapy. Herein, we develop a supramolecular approach to fabricate a nanostructured phototheranostic agent through the direct self‐assembly of two water‐soluble phthalocyanine derivatives, PcS4 and PcN4. The nature of the molecular recognition between PcS4 and PcN4 facilitates the formation of nanostructure (PcS4‐PcN4) and consequently enables the fabrication of PcS4‐PcN4 with completely quenched fluorescence and reduced singlet oxygen generation, leading to the high photoacoustic and photothermal activity of PcS4‐PcN4. In vivo evaluations suggest that PcS4‐PcN4 could not only efficiently visualize a tumor with high contrast through whole‐body photoacoustic imaging but also enable excellent photothermal therapy for cancer. 相似文献
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Dokyung Yoon Daekwang Woo Jung Heon Kim Moon Ki Kim Taesung Kim Eung-Soo Hwang Seunghyun Baik 《Journal of nanoparticle research》2011,13(6):2543-2551
The cytotoxicity of alumina nanoparticles (NPs) was investigated for a wide range of concentration (25–200 μg/mL) and incubation
time (0–72 h) using floating cells (THP-1) and adherent cells (J774A.1, A549, and 293). Alumina NPs were gradually agglomerated
over time although a significant portion of sedimentation occurred at the early stage within 6 h. A decrease of the viability
was found in floating (THP-1) and adherent (J774A.1 and A549) cells in a dose-dependent manner. However, the time-dependent
decrease in cell viability was observed only in adherent cells (J774A.1 and A549), which is predominantly related with the
sedimentation of alumina NPs in cell culture medium. The uptake of alumina NPs in macrophages and an increased cell-to-cell
adhesion in adherent cells were observed. There was no significant change in the viability of 293 cells. This in vitro test
suggests that the agglomeration and sedimentation of alumina NPs affected cellular viability depending on cell types such
as monocytes (THP-1), macrophages (J774A.1), lung carcinoma cells (A549), and embryonic kidney cells (293). 相似文献
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Hyuk Yoon Seunghyun Ahn Doseok Hwang Geunhyeong Jo Dong Woon Kim Sang Ho Kim Dongsoo Koh Yoongho Lim 《Magnetic resonance in chemistry : MRC》2012,50(11):759-764
Several types of chalcones containing 2H‐chromen group were synthesized. Claisen–Schmidt condensation of 2H‐chromen‐3‐carbaldehydes (I) with methoxy substituted acetophenones afforded (E)‐3‐(2H‐chromen‐3‐yl)‐1‐(methoxyphenyl)prop‐2‐en‐1‐ones (chromenylchalcones, 1–7). Other types of chromenylchalcone, (E)‐1‐(6‐methoxy‐2H‐chromen‐3‐yl)‐3‐(methoxyphenyl)prop‐2‐en‐1‐ones (8–13) were also obtained between reaction of methoxy substituted benzaldehydes and 1‐(6‐methoxy‐2H‐chromen‐3‐yl)ethanone (II). Dichromenylchalcones (14–16) were also synthesized through the same reaction between aldehydes (I) and ketone (II). Their complete 1H‐NMR and 13C‐NMR assignments are reported here and more polysubstituted chromenylchalcones synthesized or isolated from the natural sources in the future can be identified on the basis of the NMR data reported here. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Ultracompact high-efficiency polarizing beam splitter with a hybrid photonic crystal and conventional waveguide structure 总被引:1,自引:0,他引:1
We propose an ultracompact high-efficiency polarizing beam splitter that operates over a wide wavelength range and is based on a hybrid photonic crystal and a conventional waveguide structure. Within a small area (15 microm x 10 microm), this polarizing beam splitter separates TM- and TE-polarized modes into orthogonal output waveguides. Results of simulations with the two-dimensional finite-difference time-domain method show that 99.3% of TM-polarized light is deflected by the photonic crystal structure (with a 28.0-dB extinction ratio), whereas 99.0% of TE-polarized light propagates through the structure (with a 32.2-dB extinction ratio). Wave vector diagrams are employed to explain the operation of a polarizing beam splitter. Tolerance analysis reveals a large tolerance to fabrication errors. 相似文献
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Dr. Chiyoung Park Dr. Beom Joo Yang Ki Beom Jeong Dr. Chae Bin Kim Prof. Seunghyun Lee Dr. Bon-Cheol Ku 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(20):5577-5581
The coordination chemistry of plant polyphenols and metal ions can be used for coating various substrates and for creating modular superstructures. We herein explored this chemistry for the controlled release of guests from mesoporous silica nanoparticles (MSNs). The selective adsorption of tannic acids (TAs) on MSN silica walls opens the MSN mesoporous channels without disturbing mass transport. The channel may be closed by the coordination of TA with CuII ions. Upon exposure to light, photolysis of Trojan horse guests (photoacid generators, PAGs) leads to acid generation, which enables the release of payloads by decomposing the outer coordination shell consisting of TA and CuII. We also fabricated a modular assembly of MSNs on glass substrates. The photoresponsive release characteristics of the resulting film are similar to those of the individual MSNs. This method is a fast and facile strategy for producing photoresponsive nanocontainers by non-covalent engineering of MSN surfaces that should be suitable for various applications in materials science. 相似文献
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Choi JK Jang S Kim KJ Sohn H Jeong HD 《Journal of the American Chemical Society》2011,133(20):7764-7785
A new kind of organic-inorganic hybrid polymer, poly(tetraphenyl)silole siloxane, was invented and synthesized for realization of its unique charge trap properties. The organic portions consisting of (tetraphenyl)silole rings were responsible for negative charge trapping, while the Si-O-Si inorganic linkages provided the intrachain energy barrier for controlling electron transport. The polysilole siloxane dielectric thin films were fabricated by spin-coating and curing of the polymers, followed by characterization with spectroscopic ellipsometry (SE), near edge X-ray absorption fine structure spectroscopy (NEXAFS), and photoemission spectroscopy (PES). The abrupt increase in density and decrease in thickness of the thin film at a curing temperature of 100 °C was attributed to a thermodynamically preferred state in the nanoscopic arrangement of the polymer chains; this was due to cofacial π-π interactions in a skewed manner between peripheral phenyl groups of the (tetraphenyl)silole rings of the adjacent polymer chains. Using the NEXAFS spectrum to assess high electron affinity, the LUMO energy level of the dielectric thin film cured at 150 °C was positioned 1 eV above the Fermi energy level (E(F)). The electron trapping of the dielectric thin films was confirmed from the positive flat band shift (ΔV(FB)) in the capacitance-voltage (C-V) measurements performed within the metal-insulator-semiconductor (MIS) device structure, which strongly verified the polymer design concept. From the simple kinetics model of the electron transport, it was proposed that the flat band shift (ΔV(FB)) or trap density of the negative charges (|ρ|) was logarithmically proportional to the decay constant (β) for the electron-tunneling process. When a phenyl group of a silole ring in a polymer chain was inserted into the two available phenyl groups of another silole ring in another polymer chain, the electron transfer between the groups was enhanced, decreasing the trap density of the negative charges (|ρ|). For the thermodynamically preferred state generating the high refractive index, the distance between the two phenyl groups of the adjacent polymer chains was estimated to be in the range of 0.27-0.36 nm. 相似文献
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