Journal of Nanotechnology
·
2023
·
IF 4.2
Caining Zhang,Xuman Wang
Superhydrophobic cotton fabric with photoinduced reversibly switchable wettability was prepared by a coating of the hydrophobic copolymer and α-Fe2O3 nanoparticles. The surface morphology of the fabric was observed by scanning electron microscope (SEM). The wettability of the surface was tested under UV illumination and after storage in the dark. The chemical composition of the cotton fabric surfaces before and after UV illumination was analyzed using an X-ray photoelectron spectroscope (XPS) and FTIR. The experimental results showed that the prepared cotton fabric exhibited the excellent superhydrophobic property with a contact angle (CA) of 157.3 ± 2.9°, and became superhydrophilic after UV illumination for 64 h. The surface wettability reverted back to its initial superhydrophobic state after being stored in the dark for 30 d. Based on the XPS and FTIR analyses, the possible mechanism was discussed, and the switchable wettability was caused by the content change of the hydroxyl groups on the α-Fe2O3 surface. Moreover, the superhydrophobic cotton fabric also became superhydrophilic after sunlight illumination for 120 h.
研究领域:
材料科学
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
THIN SOLID FILMS
·
2024
·
IF 2
Xiaoyan Pan,Qingquan Zhang
This paper introduces a simple, robust and inexpensive method to create a thermal responsive coating for glass. The coating is a copolymer of N‑isopropylacrylamide (NIPAAm) and acrylamide (AAm), which can switch between clear and opaque states reversibly. The switching temperature can be adjusted from 32°C to 40°C by varying the percentage of acrylamide. The coating remains stable after switching 30 times and possesses switching function after six months storage at room temperature. These advanced properties enable the smart coating to be suitable for privacy and solar adaptive control.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2018
·Vol. 20
·期 18
·4236-4244
·
IF 8.586
Xiaoyan Pei,Dazhen Xiong,Yuanchao Pei,Huiyong Wang,Jianji Wang
Phase separation of microemulsions plays an important role in many applications such as oil recovery, nanomaterials synthesis, and chemical reactions. However, reversible switching from ionic liquid-based microemulsions to complete oil–water phase separation has not been reported so far. In this work, we developed a novel class of stimuli-responsive microemulsions composed of CO2-responsive ionic liquids, n-pentanol and water. The microstructures and phase behavior of the microemulsion systems before and after the bubbling of CO2 were investigated by electrical conductivity, dynamic light scattering, small-angle X-ray scattering, cryogenic transmission electron microscopy, and optical microscopy. It was found that these microemulsions could be reversibly switched from W/O monophase to complete oil–water phase separation upon alternate bubbling and removal of CO2 at atmospheric pressure. Furthermore, 13C NMR spectroscopy was used to understand the CO2-driven reversible phase separation of the microemulsions. The results suggest that the mechanism behind the reversible phase separation involved the reversible formation of bicarbonate and carbamate from the reaction between CO2 and the anions of the ionic liquids in the presence of water, which resulted in the increase of ionic strength (or vice versa) in the mixture. Using the microemulsions as microreactors, the phase separation protocol was applied in the Knoevenagel reaction for an efficient coupling of a chemical reaction, product separation, and recycling of the microemulsions.
研究领域:
化学工程
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材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2022
·Vol. 6
·期 5
·623-632
·
IF 8.683
Guofeng Zhang,Linqi Huang,Fuchao Yang
Photochromic materials with anti-water properties have impressive practical value, but their applications are severely hindered by their poor stability and slow colour-switching rate. Inspired by the superhydrophobicity of lotus leaves and the photochromic features of chameleons, herein we innovatively report a multifunctional material with stable superhydrophobicity and rapid photochromism. Initially, the extracted cellulose nanocrystals were utilized as the skeleton. After loading tungsten trioxide (TT) and Ketjen black (KB) on cellulose nanocrystals, the hybrid color-changing TT based sheet and composite conductive KB based sheet were constructed. Next, the TT sheet (upper layer and lower layer) and KB sheet (middle layer) were bonded with sodium carboxymethyl cellulose to prepare a sandwich-like laminated structure (denoted as TKT). Subsequently, TKT was modified by polydimethylsiloxane (PDMS) to prepare multifunctional PDMS@TKT. The PDMS ingredient can not only be used as an electron donor to increase the rate of discoloration but also endow PDMS@TKT with excellent waterproof performance. The superhydrophobicity of PDMS@TKT can withstand finger rubbing, temperature changes, acid–base corrosion, and UV radiation. PDMS@TKT can change its colour after 60 s of ultraviolet irradiation and then restore its original color after heating for 5 min, showing fast and highly reversible switching. Thus, PDMS@TKT has great potential for application in the fields of waterproof posters, light-driven sensors, and anti-counterfeiting security.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2021
·Vol. 306
·期 11
·2100379
·
IF 4.367
Qiaofeng Gao,Pengju Pan,Guorong Shan,Miao Du
Stimuli-responsive materials with multiple functions occupy a significant position in the research of bionic artificial intelligence materials. It is a challenge to integrate rapid shape deformation and color change synergistically by a simple method in the same system. Herein, an effective strategy to develop an anisotropic bilayer hydrogel actuator with unified complex deformation and color change is proposed via combining the near-infrared (NIR) light-responsive graphene oxide/poly( N -isopropylacrylamide) (GO-PNIPAM) active hydrogel layer and an UV light-responsive fluorescent poly(acrylic acid [4-(1,2,2-triphenylvinyl)] benzyl ester/ N -isopropylacrylamide) passive hydrogel layer. The actuator can undergo light-controlled sapphire fluorescence color change and complex shape deformation simultaneously or separately under light irradiation. It can be remotely manipulated without the requirement for additional reagents, and the irradiation dosage can be accurately modulated through adjusting the irradiation parameters. This work provides new perspectives of intelligent systems with synergistic multiple functions, including smart robots, environmental sensors, and intelligent biomimetic devices.
研究领域:
材料科学
·
仿生学
·
智能材料
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2016
·
IF 3.993
Yunlei Shi,Dazhen Xiong,Huiyong Wang,Yang Zhao,Jianji Wang
The creation of CO2-responsive materials that undergo structural transition between micelle and vesicle is of great importance from both theoretical and practical points of view. In this work, we have developed a series of CO2-responsive single-tailed amphiphilic ionic liquids (ILs) composed of N-alkyl-N-methyldiethanolamine cation [CnMDEA]+ (n = 8, 10, 12, 14, 16, 18) and 2-pyrrolidinone [2-Pyr]− anion. The aggregation behavior and self-assembly structures of the ILs in aqueous solution have been investigated by conductivity, surface tension, dynamic light scattering, cryogenic transmission electron microscopy, small-angle X-ray scattering, and nuclear magnetic resonance spectroscopy. For the first time, CO2 driven reversible switching of self-assembly between spherical micelle and unilamellar vesicle is found for [CnMDEA][2-Pyr] (n = 16, 18) in aqueous solutions at 20 °C and atmospheric pressure. It is shown that the mechanism behind the reversible micelle to vesicle transition involves the formation of carbamate anion from the reaction between [2-Pyr]− and CO2.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Horizons
·
2023
·
IF 13.3
Yan-Qin Wang,Min Cao,Bo-Wen Liu,Fu-Rong Zeng,Qiang Fu,Hai-Bo Zhao,Yu-Zhong Wang
Smart and dynamic electromagnetic interference (EMI) shielding materials possess a remarkable capacity to modify their EMI shielding abilities, rendering them invaluable in various civil and military applications. However, the present response mechanism of switch-type EMI shielding materials is slightly restricted, as it primarily depends on continuous pressure induction, thereby resulting in concerns regarding their durability and reliability. Herein, for the first time, we demonstrate a novel method for achieving solvent-responsive, reversible switching, and robust EMI shielding capabilities using a controlled proton-reservoir ordered gel. The gel contains polyaniline (PANI) and sodium alginate (SA). Initially, SA acts as a proton reservoir for PANI in an aqueous system, enhancing the doping level of PANI and improving its electrical conductivity. Additionally, PANI and SA chains respond to diverse polar solvents, such as water, acetonitrile, ethanol, n-hexane, and air, inducing distinct conformations that affect the degree of PANI conjugation and electron migration along the chains. This process is reversible and non-destructive to the polymer chain, ensuring the effective and uncompromised performance of the EMI shielding switch. We can achieve precise and reversible tuning (on/off) of EMI shielding with different effectiveness levels by manipulating the solvents within the framework. This work opens a new solvent-stimuli avenue for the development of EMI shielding materials with reliable and intelligent on/off switching capabilities.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2015
·Vol. 11
·期 35
·6927-6937
·
IF 4.029
Nina Yan,Yong Wang
Switchable nanoporous films, which can repeatedly alternate their porosities, are of great interest in a diversity of fields. Currently these intelligent materials are mostly based on polyelectrolytes and their porosities can change only in relatively narrow ranges, typically under wet conditions, severely limiting their applications. Here we develop a new system, which is capable of reversibly switching between a highly porous state and a nonporous state dozens of times regulated simply by exposure to selective solvents. In this system nanopores are created or reversibly eliminated in films of a block copolymer, polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP), by exposing the films to P2VP-selective or PS-selective solvents, respectively. The mechanism of the switch is based on the selective swelling of the constituent blocks in corresponding solvents, which is a nondestructive and easily controllable process enabling the repeatable and ample switch between the open and the closed state. Systematic microscopic and ellipsometric characterization methods are performed to elucidate the pore-closing course induced by nonsolvents and the cycling between the pore-open and the pore-closed state up to 20 times. The affinity of the solvent for PS blocks is found to play a dominating role in determining the pore-closing process and the porosities of the pore-open films increase with the cycling numbers as a result of loose packing conditions of the polymer chains. We finally demonstrate the potential applications of these films as intelligent antireflection coatings and drug carriers.
研究领域:
材料科学
·
化学工程
·
高分子科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Dong-Yang Li,Jun-Hua Song,Zi-Yan Xu,Yu-Jia Gao,Xu Yin,Yu-Han Hou,Li-Juan Feng,Cheng-Yang Yue,Honghan Fei,Xiao-Wu Lei
Hybrid metal halides are an emerging class of highly efficient photoluminescent (PL) materials. However, very few of them show reversible on–off PL switching under external stimuli and have the potential to perform as next-generation intelligent materials with applications in cutting-edge photoelectric devices. Herein, we report single crystal-to-single crystal (SC–SC) structural and PL transitions among three 0D hybrid antimony halides, namely, nonemissive α-[DHEP]SbCl5 (1), yellow-emissive β-[DHEP]SbCl5·2H2O (2), and red-emissive β-[DHEP]SbCl5 (3), by a dynamic phonon-engineering strategy. The reversible SC–SC transformation between 1 and 2 is triggered by acetone or methanol, affording the reversible PL on–off switching. The transition between yellow-emissive and red-emissive solids is achieved by the reversible SC–SC transformation between 2 and 3 through the process of removal/adsorption of guest water molecules. Meanwhile, the 3 to 1 transition is performed by the introduction of methanol, which is accompanied by the quenching of red emission. Therefore, a triple-mode reversible PL off–onI–onII–off switching is realized in metal halide hybrids for the first time, including the off–onI (yellow), color-tunable onI–onII (yellow-red), and onII–off (red) modes. More importantly, the reversible PL switching in 0D hybrid antimony halides make them suitable for successful applications in the protection and anti-counterfeiting of confidential information as well as in optical logic gates.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Xiaotong Wang,Qingling Zhao,Qinghong Song,He Bu,Jie Gao,Lanlan Li,Xiaofei Yu,Xiaojing Yang,Zunming Lu,Xinghua Zhang
Carbon dots (CDs) possess the merits such as energy efficiency, green sustainability and environmental friendliness, comparing with top-down synthesis methods at higher pressure or temperature condition. Here, a variety of emission states CDs were prepared by using the method of room temperature chemistry by selecting green raw materials such as glucose, p-phthalaldehyde and m-diethylaminophenol. The luminescence mechanism was studied in detail. The luminescent center of blue emitting carbon dots (B-CDs) and green emitting carbon dots (G-CDs) is C O bond, and the increased contents of C O bond lead to the creation of new energy levels between the energy gaps of HOMO and LUMO levels, which results in the red shift of luminescence wavelength. The emission state of red emitting carbon dots (R-CDs) is due to the formation of amino N. In addition, R-CDs have an exclusive respond to dopamine (DA) and are regarded as good fluorescent probes for detecting DA. Furthermore, the addition of ascorbic acid (AA) restores the luminescence of R-CDs quenched by DA. Therefore, R-CDs has great application potential as a selective fluorescent “turn on-off” probe.
研究领域:
化学
·
生物分析
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Zhenghao Zhang,Bo Peng,Yupeng Zhang,Jiaxin Xiong,Jingwei Li,Jianwei Liu
A CO2/N2-responsive emulsion provides milder reaction conditions, nontoxicity, and economic feasibility compared to other switchable surfactants. In this study, CO2/N2-responsive pickering emulsions were fabricated by using a compounded dispersion containing SiO2 nanoparticles (NPs) and superamphiphiles as the emulsifying agents. The synergistic effects of the SiO2 NPs and superamphiphiles significantly stabilized the emulsion at all of the tested concentrations and prevented complete phase separation of oil and water. The electrostatic interaction between the SiO2 NPs and superamphiphiles was disrupted after bubbling with CO2 for 30 s, resulting in the breaking of the emulsion. However, the dispersion recovered its interfacial activity after the introduction of N2 and again emulsified the emulsion. This reversible switching behavior was validated through three consecutive cycles of bubbling CO2/N2. The protonation and deprotonation of the SiO2 NPs and superamphiphiles in response to CO2/N2 facilitated reversible assembly and disassembly, which enabled the switching of the emulsions between inactive and active forms. The novel highly stable Pickering emulsions demonstrated rapid demulsification and emulsification in response to CO2/N2 and are promising for a wide range of applications.
研究领域:
材料科学
·
化学工程
·
胶体与界面科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Cheng Cheng,Zhaokang Zheng,Aiwu Wang
Photochromic smart windows allow for simple manufacturing without the need for additional energy input for adaptive control of sunlight, which will have a huge impact on the comfort of daylight and the development of smart windows. Among them, although molybdenum-based materials have advantages such as low cost and stable coloring, the lack of fast transmission switching capability and liquid phase color changing environment limit its implementation in the field of smart windows. Here, we report a low-cost method to fabricate a novel photochromic hydrogel (MoOx/PVA) by combining molybdenum oxide nanosheets (MoOx, 2 ≤ x ≤ 3) with polyvinyl alcohol (PVA) gel. Under ultraviolet light (UV = 360–400 nm) irradiation, the hydrogel achieves rapid color change visible to the naked eye within 10 s, with an exponential decrease in transmittance, reversible switching of transparency between 70 % and 5 %, and retains about 95 % transmittance after 14 cycles. Due to the good biocompatibility of molybdenum oxide, hydrogel can also be used for personal wearable, which can achieve 1.4 °C of cooling when exposed to sunlight for 3 min. Moreover, the photochromic and recovery properties of the large-sized (29.7 cm × 21 cm) MoOx/PVA hydrogel demonstrate its broad prospects for production applications in smart windows. It is believed that this study will open new opportunities for both fabrication and application in photochromic smart windows and intelligent devices.
研究领域:
材料科学
·
光电技术
·
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）