19 research outputs found

    Dual Electric/Magnetic Field-Modulated Nematic Liquid Crystal Smart Window Based on the Supramolecular Doping Effect of Halloysite Nanotube Directors

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    Nowadays in the environmentally friendly society, smart windows have been viewed as one of the attractive energy-saving technologies for green buildings. However, some inherent defects on anisotropy and compatibility still greatly limit their practical applications. Thus, we first utilized hollow heterocharged halloysite (HAL) nanotubes as the doping agent to build up a 4-cyano-4′-pentylbiphenyl (5CB)-based supramolecular liquid crystal (LC) composite with excellent electro-optical properties. In particular, the chemical modification of 5CB blocks on the surface of HAL nanotubes (5CB-HAL) greatly improved HAL’s compatibility with the host 5CB. In the applied alternating current (AC) electric field with a low frequency (60 Hz), the vertically aligned 5CB-HAL-doped LC composites with a low doping concentration of 1.0 wt % exhibited outstanding electrochromic performances, including high contrast (82%), a rapid response of about 200 ms, low driving threshold (0.157 V/μm), a wide viewing angle (120°), and a smooth running of at least 10,000 cycles. In particular, in situ grown superparamagnetic iron (II, III) oxide nanoparticles above the HAL nanotube surface further endowed this LC system with fresh magnetic modulation and better light tuning. It is anticipated to provide a cheap, facile, reliable, and promising technology for high-performance bimodal smart windows

    Dual Electric/Magnetic Field-Modulated Nematic Liquid Crystal Smart Window Based on the Supramolecular Doping Effect of Halloysite Nanotube Directors

    No full text
    Nowadays in the environmentally friendly society, smart windows have been viewed as one of the attractive energy-saving technologies for green buildings. However, some inherent defects on anisotropy and compatibility still greatly limit their practical applications. Thus, we first utilized hollow heterocharged halloysite (HAL) nanotubes as the doping agent to build up a 4-cyano-4′-pentylbiphenyl (5CB)-based supramolecular liquid crystal (LC) composite with excellent electro-optical properties. In particular, the chemical modification of 5CB blocks on the surface of HAL nanotubes (5CB-HAL) greatly improved HAL’s compatibility with the host 5CB. In the applied alternating current (AC) electric field with a low frequency (60 Hz), the vertically aligned 5CB-HAL-doped LC composites with a low doping concentration of 1.0 wt % exhibited outstanding electrochromic performances, including high contrast (82%), a rapid response of about 200 ms, low driving threshold (0.157 V/μm), a wide viewing angle (120°), and a smooth running of at least 10,000 cycles. In particular, in situ grown superparamagnetic iron (II, III) oxide nanoparticles above the HAL nanotube surface further endowed this LC system with fresh magnetic modulation and better light tuning. It is anticipated to provide a cheap, facile, reliable, and promising technology for high-performance bimodal smart windows

    Dual Electric/Magnetic Field-Modulated Nematic Liquid Crystal Smart Window Based on the Supramolecular Doping Effect of Halloysite Nanotube Directors

    No full text
    Nowadays in the environmentally friendly society, smart windows have been viewed as one of the attractive energy-saving technologies for green buildings. However, some inherent defects on anisotropy and compatibility still greatly limit their practical applications. Thus, we first utilized hollow heterocharged halloysite (HAL) nanotubes as the doping agent to build up a 4-cyano-4′-pentylbiphenyl (5CB)-based supramolecular liquid crystal (LC) composite with excellent electro-optical properties. In particular, the chemical modification of 5CB blocks on the surface of HAL nanotubes (5CB-HAL) greatly improved HAL’s compatibility with the host 5CB. In the applied alternating current (AC) electric field with a low frequency (60 Hz), the vertically aligned 5CB-HAL-doped LC composites with a low doping concentration of 1.0 wt % exhibited outstanding electrochromic performances, including high contrast (82%), a rapid response of about 200 ms, low driving threshold (0.157 V/μm), a wide viewing angle (120°), and a smooth running of at least 10,000 cycles. In particular, in situ grown superparamagnetic iron (II, III) oxide nanoparticles above the HAL nanotube surface further endowed this LC system with fresh magnetic modulation and better light tuning. It is anticipated to provide a cheap, facile, reliable, and promising technology for high-performance bimodal smart windows

    Three-Dimensional Crumpled Graphene-Based Nanosheets with Ultrahigh NO<sub>2</sub> Gas Sensibility

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    It is well-established that the structures dominate the properties. Inspired by the highly contorted and crumpled maxilloturbinate inside dog nose, herein an artificial nanostructure, i.e., 3D crumpled graphene-based nanosheets, is reported with the simple fabrication, detailed characterizations, and efficient gas-sensing applications. A facile supramolecular noncovalent assembly is introduced to modify graphene with functional molecules, followed with a lyophilization process to massively transform 2D plane graphene-based nanosheets to 3D crumpled structure. The detailed morphological characterizations reveal that the bioinspired nanosheets exhibit full consistency with maxilloturbinate. The fabricated 3D crumpled graphene-based sensors exhibit ultrahigh response (<i>R</i><sub>a</sub>/R<sub>g</sub> = 3.8) toward 10 ppm of NO<sub>2</sub>, which is mainly attributed to the specific maxilloturbinate-mimic structure. The sensors also exhibit excellent selectivity and sensing linearity, reliable repeatability, and stability. Interestingly, it is observed that only 4 mg of graphene oxide (GO) raw materials can produce more than 1000 gas sensors, which provides a new insight for developing novel 3D biomimetic materials in large-scale gas sensor production

    A Facile Approach to Fabricate Sustainable and Large-Scale Photothermal Polydopamine-Coated Cotton Fabrics for Efficient Interfacial Solar Steam Generation

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    A facile approach to fabricate sustainable and large-scale polydopamine (PDA) and silver nanoparticle (AgNP)-coated cotton fabrics (P-Ag-P@CFs) as photothermal solar evaporators for efficient interfacial solar steam generation was proposed. The P-Ag-P@CFs were facilely fabricated in a large scale (2.3 m × 1.0 m) by coating PDA and AgNPs on cheap and green cotton fabrics via the self-polymerization of dopamine through a dip-coating combined with oven drying method and in situ reduction of Ag+ by dopamine, respectively. Thanks to the synergistic effect of PDA and AgNPs, the P-Ag-P@CFs show remarkable light absorption and solar-to-vapor efficiency (over 90% for deionized water under 1-sun irradiation), resulting in a high evaporation rate of 1.378 kg m–2 h–1. Moreover, the P-Ag-P@CFs display an excellent purification efficiency and degree for several kinds of aqueous solutions, such as seawater, simulated sewage, and industrial wastewater. The desalinated water is compliant with the standards of drinking water

    Easily Processable Temperature-Responsive Infrared-Reflective Polymer Coatings

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    A temperature-responsive near-infrared reflective coating was fabricated based on a side-chain liquid crystal siloxane polymer using a simple wired-bar method. The cholesteric liquid crystalline polymer film showed a blue shift of the reflection band of ∼1000 nm in the IR region upon heating. The temperature-responsive change of the reflection band was reversible. Compared to that of the same mixture system in an alignment cell, the coating showed a significantly faster response. This research demonstrates an easy way to prepare a temperature-responsive IR-reflective coating that shifts its reflection to a shorter wavelength upon heating. As IR radiation of shorter wavelengths is more strongly represented in sunlight than longer wavelengths, this coating could be used to selectively reduce heating of an indoor space when the temperature is high. This is promising for the future application of smart climate control

    A Facile Approach to Fabricate Sustainable and Large-Scale Photothermal Polydopamine-Coated Cotton Fabrics for Efficient Interfacial Solar Steam Generation

    No full text
    A facile approach to fabricate sustainable and large-scale polydopamine (PDA) and silver nanoparticle (AgNP)-coated cotton fabrics (P-Ag-P@CFs) as photothermal solar evaporators for efficient interfacial solar steam generation was proposed. The P-Ag-P@CFs were facilely fabricated in a large scale (2.3 m × 1.0 m) by coating PDA and AgNPs on cheap and green cotton fabrics via the self-polymerization of dopamine through a dip-coating combined with oven drying method and in situ reduction of Ag+ by dopamine, respectively. Thanks to the synergistic effect of PDA and AgNPs, the P-Ag-P@CFs show remarkable light absorption and solar-to-vapor efficiency (over 90% for deionized water under 1-sun irradiation), resulting in a high evaporation rate of 1.378 kg m–2 h–1. Moreover, the P-Ag-P@CFs display an excellent purification efficiency and degree for several kinds of aqueous solutions, such as seawater, simulated sewage, and industrial wastewater. The desalinated water is compliant with the standards of drinking water

    A Facile Approach to Fabricate Sustainable and Large-Scale Photothermal Polydopamine-Coated Cotton Fabrics for Efficient Interfacial Solar Steam Generation

    No full text
    A facile approach to fabricate sustainable and large-scale polydopamine (PDA) and silver nanoparticle (AgNP)-coated cotton fabrics (P-Ag-P@CFs) as photothermal solar evaporators for efficient interfacial solar steam generation was proposed. The P-Ag-P@CFs were facilely fabricated in a large scale (2.3 m × 1.0 m) by coating PDA and AgNPs on cheap and green cotton fabrics via the self-polymerization of dopamine through a dip-coating combined with oven drying method and in situ reduction of Ag+ by dopamine, respectively. Thanks to the synergistic effect of PDA and AgNPs, the P-Ag-P@CFs show remarkable light absorption and solar-to-vapor efficiency (over 90% for deionized water under 1-sun irradiation), resulting in a high evaporation rate of 1.378 kg m–2 h–1. Moreover, the P-Ag-P@CFs display an excellent purification efficiency and degree for several kinds of aqueous solutions, such as seawater, simulated sewage, and industrial wastewater. The desalinated water is compliant with the standards of drinking water

    Development of Cyclic Tetrasiloxane Polymer as a High-Performance Dielectric and Hydrophobic Layer for Electrowetting Displays

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    Cyclic tetrasiloxane polymer (CTP) has recently garnered interest as a hydrophobic material with unique properties. This study aims to enhance the dielectric constant of CTP films by introducing excess Si–H groups and to explore the impact of synthesis and processing conditions on the resulting properties. The film demonstrates high hydrophobicity, with contact angles of 107° in air and 165° in n-decane, along with a notable dielectric constant of 5.1°. Furthermore, the CTP film displays reversible electrowetting behavior with low contact angle hysteresis (2°) and possesses good transparency (∼99%) and thermal stability. As such, the CTP film has significant potential as a material for the electric wetting of hydrophobic dielectric layers and may serve as a promising alternative in electrowetting applications

    Combining ZnO and Organosilica Nanodots as a Thick Cathode Interlayer for Highly Efficient and Stable Inverted Polymer Solar Cells

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    Low-work-function metal oxides as cathode interlayers are widely used in polymer organic solar cells (PSCs), but the surface defect and intrinsic photocatalysis issues severely affect the high efficiency, thickness insensitivity, and stability of PSCs. In this work, we used organosilica nanodots (OSiNDs) to modify ZnO as cathode interlayers via the self-assembly method. The ZnO/OSiNDs bilayer can acquire a suitable work function and a high conductivity of 5.87 × 10–4 S m–1. Through systematic studies, there is stable surface coordination interaction of Zn–N bonding between ZnO and OSiNDs. In i-PSCs, using D18:Y6 as the active layer, the ZnO/OSiNDs-based device achieves the best PCE of 17.87%. More importantly, due to the high conductivity, the PCE for the device based on a 68 nm thick ZnO/OSiNDs interlayer is still high up to 16.53%, while the PCE for the device based on a 66 nm thick ZnO interlayer is only 13.18%. For photostability, the PCE of the device based on the ZnO/OSiNDs interlayer maintains 95% of its original value after continuous AM 1.5G illumination (contains UV light) at 100 mW/cm2 for 600 min, while that of the ZnO-based device only maintains 72% of the original value. This work suggests that ZnO/OSiNDs can be utilized as a cathode interlayer to fabricate highly efficient and stable PSC over a wide range of thicknesses
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