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oe1(光电查) - 科学论文

83 条数据
?? 中文(中国)
  • Endowing Light-Inert Aqueous Surfactant Two-Phase System with Photo Responsiveness by Introducing a Trojan Horse

    摘要: The ability to modulate the phase behavior of aqueous surfactant two-phase (ASTP) system reversibly with light is of great importance in both fundamental and applied science. Thus far, most of the light-responsive ASTP systems are based on covalent-modification of the component molecules. In this article, we for the first time achieve photo-responsiveness in a light-inert ASTP system by physically introducing a photo-trigger with the aid of an Trojan Horse. The ATPS system formed with sodium laurate (SL) and dodecyl tributyl amomium (DBAB) doesn’t show light responsiveness by physically mixing a light responsive azobenzene compound, 2-(4-(phenyldiazenyl)phenoxy)actate sodium (Azo). However, in the presence of the host-guest complex SL@β-CD formed with β-CD and sodium laurate (SL), the ASTP turns quickly into a homogenous suspension under visible light, which recovers to the original ASTP state again under 365 nm UV irradiation. Because the SL@β-CD complex exists harmonically with the ASTP, it can be viewed as a “Trojan horse” that becomes fatal only when the encapsulated SL is triggered to release. In the presence of the Trojan horse, the photo-responsiveness of the ASTP can be manipulated reversibly by alternatively exerting UV and visible light. Using this strategy, we are able to collect trace amount of oily components from water. The current strategy points out that it is possible to achieve light-responsiveness in light-inert systems with physical method, which may have profound impact both on the fundamental and applied science.

    关键词: Cyclodextrin,Azobenzene,Trojan horse,Host-Guest Interaction,Aqueous surfactant two-phase system,Photo-Responsive

    更新于2025-11-25 10:30:42

  • Dispirocycles: Novel Platforms for Construction of High-Performance Host Materials for Phosphorescent Organic Light-Emitting Diodes

    摘要: Spirocycle compounds such as 9,9′-Spirobifluorene (SBF) are becoming more and more attractive for use as the host materials in organic optoelectronic devices. In this manuscript, two dispirocycles, namely dispiro[fluorene-9,9?-anthracene-10?,9??-fluorene] and 10,10??-diphenyl-10H,10??H-dispiro[acridine-9,9?-anthracene-10?,9??-acridine] were used for the construction of hosts materials (1, 2, 3, and 4). The attached triphenylamine group would determine the thermal, photophysical, electrochemical, and charge transport properties, and therefore they have different electroluminescence performances. The device based on dispiro[fluorene-9,9?-anthracene-10?,9??-fluorene] (2) and 10,10??-diphenyl-10H,10??H-dispiro[acridine-9,9?-anthracene-10?,9??-acridine] (3) molecular platforms exhibited a external quantum efficiency of over 21% with a very high power efficiency (~100 lm W-1). The results here demonstrate to us the potential of extending the possibilities of applying the dispirocyclic molecular platforms with inherent rigidity for developing highly efficient host materials for OLEDs.

    关键词: Dispirocycles,OLEDs,Host materials,Phosphorescence,Triplet energy

    更新于2025-11-19 16:56:42

  • Determination of cholic acid in body fluids by β?cyclodextrin-modified N-doped carbon dot fluorescent probes

    摘要: An easy, dependable, and sensitive cholic acid activity experiment was designed based on β?cyclodextrin-modi?ed carbon dot (β?CD-CD) nanoprobes with speci?c host–guest recognizing ability and photoelectron transfer capability. The β?CD-CD nanoprobes were characterized by infrared, ultraviolet-visible, and ?uorescence spectroscopy and transmission electron microscopy. The ?uorescence of the probes under optimized conditions linearly responded to cholic acid concentration from 0 to 650 μmol·L?1 with a detection limit of 25 nmol·L?1. The probes also performed well in detecting cholic acid in serum and urine samples with an average recovery rate of 97.1%–103.4%. Thus, this study provides a reliable, rapid, and easy method of cholic acid detection in body ?uids that can be potentially applied in medical studies.

    关键词: Host–guest recognition,β?cyclodextrin,Cholic acid,Photoinduced electron transfer,Carbon dots

    更新于2025-11-14 17:03:37

  • Effect of exciton diffusion on the triplet-triplet annihilation rate in organic semiconductor host-guest systems

    摘要: We study the contribution of triplet exciton diffusion to the efficiency loss resulting from F?rster-type triplet-triplet annihilation (TTA) in organic phosphorescent semiconductor host-guest systems, using kinetic Monte Carlo (KMC) simulations. Our study focusses on diffusion due to F?rster-type guest-guest transfer, but includes also a comparison with simulation results for the case of Dexter-type guest-guest transfer. The simulations are carried out for a wide range of F?rster radii, and for guest concentrations up to 100 mol%, with the purpose to support analyses of time-resolved photoluminescence experiments probing TTA. We find that the relative contribution of diffusion to the TTA-induced efficiency loss may be deduced quite accurately from a quantitative experimental measure for the shape of the time-dependent photoluminescence intensity, the so-called r ratio. For small guest concentrations and F?rster radii that are most relevant to organic light-emitting diodes (OLEDs), the diffusion contribution is in general quite small. Under these weak-diffusion conditions, the absolute diffusion contribution to the TTA-induced efficiency loss can be understood quantitatively using a capture radius formalism. The effective guest-guest diffusion coefficient that follows from the TTA simulations, using the capture radius formalism, agrees well with the diffusion coefficient that follows from direct KMC diffusion simulations. The simulations reveal that the diffusion coefficient is strongly affected by the randomness of the distribution of guest molecule locations.

    关键词: OLEDs,photoluminescence,kinetic Monte Carlo simulations,Dexter transfer,organic semiconductors,triplet-triplet annihilation,exciton diffusion,host-guest systems,F?rster transfer

    更新于2025-09-23 15:23:52

  • 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

  • A multi-color and white-light emissive cucurbituril/terpyridine/lanthanide supramolecular nanofiber

    摘要: Multi-color and white light luminescence materials based on supramolecular assemblies are attractive because of their potential applications in advanced light-emitting material. Herein, a cucurbit[8]uril-enhanced lanthanide luminescent supramolecular assembly was constructed in a facile but efficient way using terpyridine imidozalium cations, cucurbit[8]urils and rare earth ions such as Tb3+ and Eu3+. Significantly, the resultant fibrous supramolecular assembly, with an average width of 15 nm, could emit remarkable lanthanide luminescence, which was ten times higher than the corresponding terpyridine/Ln3+ without cucurbit[8]uril. And the solid state luminescence of supramolecular assembly could be smartly and easily turned among blue, green, red and white by adjusting the molar ratios between Tb3+ and Eu3+. The enhanced white-light emission by supramolecular strategy may provide a new approach for smart and tunable solid luminescent materials.

    关键词: Cucurbit[8]uril,White-light emission,Supramolecular chemistry,Host-guest interaction,Lanthanide luminescence

    更新于2025-09-23 15:23:52

  • Optically switchable bistable guest–host displays in chiral-azobenzene- and dichroic-dye-doped cholesteric liquid crystals

    摘要: Optically switchable bistable guest–host displays in chiral-azobenzene- and dichroic-dye-doped cholesteric liquid crystals (CA-DD-CLCs) are demonstrated. The CA-DD-CLCs in a LC cell treated by homeotropic alignment are initially in stable unwound textures. Given that all LC molecules in unwound textures are oriented perpendicularly to the substrates, the light absorbed by the doped DDs reaches the minimum value, which is considered the transparent state of the proposed CA-DD-CLCs. The CA-DD-CLCs are switched to fingerprint (FP) textures by illumination with ultraviolet (UV) light and can be switched back to unwound textures by illumination with green light. The optical switching between unwound and FP textures is based on the photo-tunable chirality of the doped CA via photoisomerization effect. The light absorbed by the doped DDs in FP textures reaches the maximum value, which is considered the dark state of the CA-DD-CLCs. Moreover, the performances of light absorption from the doped DDs when the CA-DD-CLCs are in unwound and FP textures is independent of the polarization of the incident light. Pattern information can be optically addressed (erased) in CA-DD-CLC cells by illumination with UV (green) light through a suitable photomask. The CA-DD-CLCs can be stabilized in FP textures for several tens of minutes in the dark environment. As such, the power is consumed only for the illumination of specific lights during the switching of CA-DD-CLCs between unwound and FP textures. Moreover, a transparent active matrix organic light-emitting diode (LED) display that is superimposed on top of a CA-DD-CLC cell embedded with a transparent light-guide film with suitable LED light sources for optical switching between unwound and FP textures, is proposed for augmented reality applications.

    关键词: Cholesterics,Absorption,Guest-host display,Liquid crystals,Chiral azobenzene,Dichroic dyes

    更新于2025-09-23 15:23:52

  • A New Biscarbazole-Based Metal-Organic Framework for Efficient Host-Guest Energy Transfer

    摘要: A new metal–organic framework (MOF), [Zn6L4(Me2NH2+)4·3 H2O] (1) was constructed based on [9,9’-biscarbazole]-3,3’,6,6’-tetracarboxylic acid (H4L) and Zn2+ ions. The porous framework and intense blue fluorescence of the MOF based on the biscarbazole moiety of the ligand could facilitate efficient host to guest energy transfer, which makes it an ideal platform for the tuning of luminescence.

    关键词: in situ encapsulation,metal–organic frameworks,energy transfer,host–guest systems,fluorescence

    更新于2025-09-23 15:23:52

  • Strong Emission Enhancement in pH-Responsive 2:2 Cucurbit[8]uril Complexes

    摘要: Organic fluorophores, particularly stimuli-responsive molecules, are very interesting for biological and material sciences applications, but limited by aggregation- and rotation-caused photoluminescence quenching. A series of easily accessible bipyridinium fluorophores is reported, whose emission is quenched by a twisted intramolecular charge transfer (TICT) mechanism. Encapsulation in a cucurbit[7]uril host yields a 1:1 complex exhibiting a moderate emission increase due to destabilization of the TICT state inside the apolar cucurbituril cavity. A much stronger fluorescence enhancement is observed in 2:2 complexes with the larger cucurbit[8]uril, which is caused by additional conformational restriction of rotations around the aryl-aryl bonds. As the cucurbituril complexes are pH switchable, this system represents an efficient supramolecular ON/OFF fluorescence switch.

    关键词: restriction of intramolecular motion,luminescence,host-guest complex,fluorescence enhancement,Cucurbituril

    更新于2025-09-23 15:23:52

  • Energy disorder and energy level alignment between host and dopant in organic semiconductors

    摘要: Energy level alignment between host and dopant molecules plays a critical role in exciton formation and harvesting in light emission zone of organic light-emitting diodes. Understanding the mechanism for predicting energy level alignment is thus important in materials selection for fabricating high-performance organic light-emitting devices. Here we show that host-dopant energy level alignment strongly depends on film thickness and substrate work function by using X-ray and ultraviolet photoemission spectroscopy. Invariant Gaussian density of states fails to explain the experimental data. We speculate that energy disorder in molecules next to the surface dictates the alignment. Ultraviolet photoemission spectroscopy measurements of several archetypical organic semiconductors confirm our speculation. An empirical interface disorder function is derived and used to construct a functional Gaussian density of states to compute host energy levels. Host-dopant energy level alignment is then computed by applying the universal energy alignment rule and is found in excellent agreement with the experimental data.

    关键词: Host-dopant systems,Organic semiconductors,Energy level alignment,Photoemission spectroscopy,Energy disorder

    更新于2025-09-23 15:23:52