Smart Materials and Structures
·
2020
·Vol. 29
·期 4
·04LT02
·
IF 3.613
Liangliang Cao,Liang Fang,Xue Li,Shunping Chen,Chunhua Lu,Zhongzi Xu
Chameleons are attractive animals, which can change their colors because of unique layered skin structures. Inspired by this natural design, we explored a layer-by-layer assembly technique to create thermochromic films that can attain reversible and multiple-colors change. Briefly, inorganic pigments and two kinds of thermochromic microcapsules having different responsive temperatures were assembled sequentially onto a piece of filter paper using extraction filtration before epoxy resin was used to seal the whole structure. Different functions including colorful patterns and luminescent letters can be integrated into the system using this versatile approach. More importantly, arrays of thermochromic films were used with a detector and a heating-control circuit to trigger complicated color change by varying detected colors. We believe that this cost-efficient and convenient approach can be used in multiple applications such as camouflage, anti-counterfeiting, smart constructions and buildings, etc.
研究领域:
材料科学
·
仿生学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Xiaojing Su,Hongqiang Li,Xuejun Lai,Longzhu Zheng,Zhonghua Chen,Songshan Zeng,Kuangyu Shen,Luyi Sun,Xingrong Zeng
Thermochromic films with intriguing functionalities have great potential in soft actuators, heat storage devices, and interactive interface sensors. Inspired by the unique features of bird feathers (such as Nicobar pigeon, Anna hummingbird, mandarin duck, etc.), a superhydrophobic thermochromic film (STF) with robust healability is proposed for the first time through sandwiching an electric heater between a top thermochromic layer and a bottom poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) substrate. The STF exhibits fast and reversible color conversions of blue-pink-yellow under a low input power and has a superhydrophobic property with a contact angle of 155°. Furthermore, owing to the strong dynamic dipole–dipole interactions between the polar CF3 groups of flexible PVDF-HFP chains, the STF possesses a robust healing capability of structure and conductivity. By means of the temperature difference generated by the objects contacting (finger, iron, and water) as a stimulus, the STFs achieve tactile imaging and writing record with advantages of transient display, automatic erasure, and excellent reusability. Additionally, the STF-based anti-counterfeiting security labels with superhydrophobicity and three-state color switching simultaneously realize facile distinguishment and difficult forgery. The findings conceivably stand out as a new methodology to fabricate functional thermochromic materials for innovative applications.
研究领域:
材料科学
·
仿生学
·
表面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 11
·1867
·
IF 5.719
Hexuan Yan,Luying Si,Gang Li,Lejian Zhao,Wei Luo,Huiru Ma,Jianguo Guan
The rapid and robust response to external stimulus with a large volume deformation is of huge importance for the practical application of thermo-responsive photonic crystal film (TRPCF) in actuators, colorimetric sensors, and other color-related fields. Generally, decreasing the size of thermo-responsive photonic crystals and introducing micropores are considered to be two effective approaches to improve their responsiveness. However, they usually result in a poor mechanical property, which leads to optical instability. To solve these problems, a heterogeneous thermo-responsive photonic crystal film was developed here by integrating a thermosensitive hydrogel matrix poly(N-isopropylacrylamide-co-N-methylolacrylamide) (P(NIPAM-co-NHMA)) with high-modulus, but non-thermosensitive poly(acrylic acid -co-2-hydroxyethyl methacrylate (P(AA-co-HEMA)) hydrogel-based photonic nanochains (PNCs). The as-obtained TRPCF based on PNCs (TRPCF-PNC) well combined the rapid response and improved the mechanical property. Typically, it can complete a response within 12 s from 26 to 44 °C, which was accompanied by a larger deformation of the matrix than that of the PNCs. The unique rapid thermochromic mechanism of the TRPCF-PNC is revealed here. Furthermore, it exhibits a high tensible property along the PNC-orientation direction and excellent optical stability. The response time of the TRPCF-PNC can conveniently modulate by changing the cross-linking degree of the PNCs or the content of the thermosensitive component in the matrix. The heterogeneous TRPCF-PNC is believed to have potential applications in artificial muscle and quick-response actuation devices.Keywords:thermochromic film;heterogeneous hydrogel;photonic nanochains;quick response;large deformation
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Jiayin Liu,Jialing Tan,Hao Liu,Chaoxia Wang
Thermochromic dyes (TCDs) based on a three-component color change system suffer from solid rigidity and liquid leakage issues because of the intrinsic solid–liquid phase change performance, resulting in difficulty in temperature visualization applications for smart wearable fields. Despite considerable efforts in microencapsulation of thermochromic dyes, designing and fabricating essentially flexible thermochromic phase change films still need to be explored. Herein, a one-sided adhesive gradient-crosslinked thermochromic film is reported to address these issues to make a trade-off between stability and flexibility, excellent thermochromic performance, and temperature visualization. The thermochromic wearable films have been fabricated exploiting tea polyphenol thermochromic dyes, vinyl dimethylsiloxane, and hydrosilicone oil via the salt-template-assisted method and gradient crosslinking strategy, which have porous structures with an average pore size of 12.8 μm and a porosity of 28 %. Due to the spatial limiting threshold effect of the porosity structure, interconnected 3D polysiloxane porous networks can provide ample support for tea polyphenol thermochromic dyes and effectively prevent liquid leakage. Upon heating, the thermochromic film changes from blue to white with the K/S value decreasing from 7.69 to 0.78 and the Δ E * increasing from 2.7 to 16.1 at 610 nm, and the color-changing temperature is 42 °C. Gradient crosslinked thermochromic films exhibit excellent temperature-responsive color change properties, desirable one-side adhesion, and thermal energy storage, enabling multicolor temperature displays and temperature-controlled multilevel information transfer.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Colloid and Interface Science Communications
·
2022
·
IF 5.633
Zhouzhou Zhu,Kezhen Zhu,Jianhui Guo,Zhiyang Fan,Ziyue Li,Jingwei Zhang
Monoclinic vanadium dioxide (VO 2 ) is a new type of thermally induced phase-transition material that undergoes a significant change in infrared transmittance during its phase transition, which makes it an excellent material for potential applications in the field of passive thermochromic smart windows. Improving the optical modulation capabilities and the durability of VO 2 are crucial objectives for smart window applications. In this paper, three kinds of ethanol dispersion solutions were prepared by a nanogrinding machine using the following nanoparticles: monoclinic VO 2 , tungsten-doped vanadium dioxide (WVO) and silicon dioxide-coated tungsten-doped vanadium dioxide (WVO@SiO 2 ). Polyvinyl butyral was selected as the film-forming agent, and the VO 2 composite functional films were prepared by a scraping method. The ability of the prepared composite functional films to modulate light during alternating heating and cooling cycles and to resist a reduction in activity were evaluated preliminarily by an ultraviolet light irradiation method. The results show that, compared with a pure-phase VO 2 film, tungsten-doped films can significantly enhance light modulation and the durability of the composite films. In addition, surface encapsulation by SiO 2 in combination with introducing antioxidants also contributes to significantly improved optical properties and stability of the composite films. For example, the prepared composite films retained an infrared modulation efficiency of 49.7% at 1500 nm with a visible light transmittance of more than 60% after 65 cycles of high- and low-temperature treatments, showing excellent smart thermochromic performance, cyclic stability and promising application potential. This study is expected to provide a theoretical basis and experimental data for the preparation of stable VO 2 nanomaterials and their applications to smart window films.
研究领域:
材料科学
·
纳米技术
·
光学工程
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Zihui Liang,Xiaohong Liao,Jing Yu,Zezhu Zhou,Hao Wang,Teng Zhang,Changhai Yi,Li Zhao,Fengxiang Chen,Congcong Wu
Buildings, accounting for approximately 40% of global energy consumption, heavily rely on windows for maintaining indoor comfort. However, conventional windows are known for their inefficiency due to high optical transmittance and thermal conductivity. In recent decades, efforts have focused on enhancing sustainability through the development of low-emissivity coatings and smart windows. Despite advancements, the commercialization of a vanadium dioxide (VO2) nanostructure-based thermochromic film has been limited by stability issues. This study addresses the critical need for long-term stability and efficiency in VO2-based smart windows, showcasing a composite film that is highly resilient to heat, ultraviolet (UV) light, and humidity. The proposed films exhibit exceptional solar energy regulation capability (ΔTsol = 20.11%) alongside a visible light transmittance of 54.94%. Moreover, they exhibit strong stability even under conditions of high relative humidity (90%) and temperature (60 °C), maintaining consistent phase-transition performance over 40 days─equivalent to approximately 1777 days of real-world exposure. Impressively, even without encapsulation, the composite film retains 96.4% of its initial ΔTsol after continuous 60-day illumination. This research offers promising technical solutions for advancing the commercial viability of traditional VO2 smart windows, contributing significantly to global efforts toward carbon neutrality and sustainable development.
研究领域:
材料科学
·
能源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2013
·Vol. 5
·期 19
·9208-9213
·
IF 6.233
Yijie Zhou,Aibin Huang,Yamei Li,Shidong Ji,Yanfeng Gao,Ping Jin
Transition-metal oxide nanocrystals are novel candidates for being used as the hosts of localized surface plasmon resonance because they exhibit fascinating properties arising from the unique characteristics of their outer-d valence electrons. VO2(M) nanocrystal is well-known due to its reversible metal-insulator transition (MIT) temperature near room temperature (∼68 °C) corresponding to the appearance/disappearance of localized surface plasmon resonance across the MIT. In this study, a microemulsion-based method was introduced to synthesize VO2(M)@SiO2 nanoparticles which were applied to prepare VO2-based thermochromic foils owing to a strong and tunable surface plasmon resonance in the metallic state. The optical transmittance spectra demonstrates that the employment of surface plasmon resonance in VO2-based thermochromic foils greatly improves their solar regulating efficiency up to 18.54%, and provides an unprecedented insight in optimizing VO2-based thermochromic windows for solar control.
研究领域:
材料科学
·
纳米技术
·
光学工程
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2025
·
IF 6.3
Zhengjie Chen,Chengchen Feng,Lin Jiang,Yujie Ke,Xiaoxue Han,Xinghai Liu
Smart window promises to enhance the building energy efficiency by dynamically controlling the indoor solar irradiation. In this study, a new thermochromic smart films for smart window applications were proposed. This film is based on polyvinylpyrrolidone (PVP)-coated tungsten-doped VO 2 (W-VO 2 ) and polyurethane acrylate (PUA). It is demonstrated that the PVP-coating technique plays a vital role in improving the optical properties of the film and the dispersion of W-VO 2 in PUA. The optimized 3D-printed Kirigami-structured films exhibit favorable tensile properties and improved optical properties. Furthermore, an innovative device has been developed to enable automatic adjustment of the film stretch rate in response to the angle of sunlight, ensuring the smart window's dynamic response to sunlight. The film's solar transmittance varies between 48.50 % and 78.56 % during stretching, accompanied by a solar modulation up to 30.05 %. In the indoor and outdoor demo experiments, the temperature drops by 5.2 °C and 4.8 °C, respectively, compared to a PUA film window. The work developed a new film for energy-efficient smart windows and provides a systematic technological route from materials synthesis, structural optimization, system digital control, to practical demo assessment, which promises to facilitate the development of VO 2 -based materials and energy-efficient windows.
研究领域:
材料科学
·
能源技术
·
建筑科技
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Kun Tong,Rong Li,Jingting Zhu,Heliang Yao,Huaijuan Zhou,Xianzhe Zeng,Shidong Ji,Ping Jin
VO 2 /Al-O core-shell structure (V/AO) was synthesized by a facile method and its application for thermochromic film on smart window was investigated. Comparisons of thermochromic properties and stabilities in different environments between VO 2 and annealed V/AO nanoparticles were made. As a result, VO 2 nanoparticle was easily oxidized and lost thermochromic property. In contrast, with the protection provided by Al-O-based shell, the VO 2 core remained stable at a high temperature (350 °C in air) and in H 2 O 2 solution. Especially, thermochromic films made by annealed V/AO nanoparticles almost kept thermochromic performance in damp heating environment (T=60 °C, RH=90%) for 20 days while VO 2 films lost their thermochromic properties after 3 days. Besides, the degradation progress of VO 2 and V/AO nanoparticles in damp heating environment was also explored. Results indicate that Al-O-based shell provides a good protection for the VO 2 core originated from the compact structure of shell, which effectively prevents oxygen and water from eroding VO 2 . In summary, the VO 2 nanoparticles coated with Al-O-based shell exhibit a great potential in the application of smart window.
研究领域:
材料科学
·
纳米技术
·
智能材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）