AUSTRALIAN JOURNAL OF CHEMISTRY
·
2015
·Vol. 68
·期 9
·1446-1454
·
IF 1.558
Haoran Yuan,Denian Li,Yan Liu,Chuanxi Xiong
Efficient synthesis and controlled modification of carbon dots (CDs) with tuneable properties on the basis of facile technical routes are of great significance for user-defined applications as well as more insightful understanding of the unique fluorescence from carbon nanomaterials. In this work, we report an improved nitric acid oxidization method towards low-cost and rapid preparation of fluorescent CDs. This is achieved by using industrial carbon black specimens as the precursor and implementing a reduced pressure distillation for the purpose of eliminating excessive acids. Unexpectedly, the product exhibits an interesting dual luminescence behaviour with tuneable characteristics that differs from all previously reported CDs. The strongest emissions at fixed or varied excitations can be simultaneously tuned from blue to green or yellow by simply prolonging the time of acid oxidization. These emissions show distinct stabilities in acid and alkaline environments, thereby making the resultant CDs very promising candidates for pH probes. It is further revealed that this simple synthesis and fluorescence tuning strategy is also applicable to CDs from other carbon blacks.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 22
·7623
·
IF 4.6
Yangbo Wang,Yingdong Han,Runfa Liu,Cunping Duan,Huaiyong Li
Efficient control over lanthanide luminescence by regulating excitations offers a real-time and reversible luminescence-managing strategy, which is of great importance and highly desirable for various applications, including multicolor display and information encryption. Herein, we studied the crystal structure, luminescence properties, and mechanisms of undoped and Tb3+/Eu3+-doped CaZrO3in detail. The intrinsic purple-blue luminescence from host CaZrO3and the introduced green/red luminescence from guest dopants Tb3+/Eu3+were found to have different excitation mechanisms and, therefore, different excitation wavelength ranges. This enables the regulation of luminescent color through controlling the excitation wavelengths of Tb3+/Eu3+-doped CaZrO3. Furthermore, preliminary applications for information encryption with these materials were demonstrated using portable UV lamps of 254 and 302 nm. This study not only promotes the development of multicolor luminescence regulation in fixed-composition materials, but also advances the practical applications of lanthanide luminescent materials in visually readable, high-level anti-counterfeiting and information encryption.Keywords:luminescence;lanthanide;multicolor emission;luminescence regulation;information encryption
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
LANGMUIR
·
2020
·
IF 3.557
Tao Wang,Ran Kou,Jian Zhang,Renwei Zhu,Hongtao Cai,Guangming Liu
In this work, a negatively charged poly(3-sulfopropyl methacrylate potassium) (PSPMA) brush has been employed as a model system to demonstrate the tuning of the light response of strong polyelectrolyte brushes (SPBs) with counterions. The substitution of K+ counterions by azobenzene-containing counterions (Azo-N+) renders the PSPMA brush light-responsive in aqueous solutions. Nevertheless, the strength of the light response of the PSPMA brush is weak due to the inefficient disassembly of the micelle-like aggregates in the brush upon irradiation with ultraviolet light. Counterion mixtures of Azo-N+ and K+ are employed to realize a strong light response of the PSPMA brush by incorporating a reasonable amount of Azo-N+ counterions into the brush. The strength of the light response of the PSPMA brush can be tuned by the mole ratio of Azo-N+ to K+. Furthermore, properties including the hydration and conformation of the PSPMA brush can be reversibly switched via alternating ultraviolet and visible light irradiation. This work opens up the opportunities available for the use of counterions to tune the light response of SPBs.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Advanced Photonics Nexus
·
2023
·
IF 0
Haiyang Liu,Zongnan Zhang,Yingqiu Li,Yaping Wu,Zhiming Wu,Xu Li,Chunmiao Zhang,Feiya Xu,Junyong Kang
Achieving valley pseudospin with large polarization is crucial in the implementation of quantum information applications. Transition metal dichalcogenides (TMDC) with different phase structures provide an ideal platform for valley modulation. The valley splitting has been achieved in hybrid phase WSe2, while its valley polarization remains unstudied. Magnetic field controllable valley polarization is explored in WSe2 with coexistence of H and T phases by an all-optical route. A record high valley polarization of 58.3% is acquired with a 19.9% T phase concentration under a 4-T magnetic field and nonresonant excitation. The enhanced valley polarization is dependent on the phase component and shows various increasing slopes, owing to the synergy between the T phase WSe2 and the magnetic field. The magnetic field controlled local magnetic momentums are revealed as the mechanism for the large valley polarization in H / T-WSe2. This speculation is also verified by theoretical simulations of the nonequilibrium spin density. These results display a considerable valley magnetic response in phase-engineered TMDC and provide a large-scale scheme for valley polarization applications.
研究领域:
凝聚态物理
·
材料科学
·
量子信息
·
光学调控
·
二维材料
✓ 已验证
DOI
OPTICS EXPRESS
·
2025
·Vol. 33
·期 6
·13895-13906
·
IF 3.3
Xiaoxiao Chen,Xueguang Lu,Lu Tang,Kefan Chen,Wanxia Huang
Despite striking advances in terahertz (THz) sources and detectors, the exploitation of active materials that can alter their properties in response to external excitations for the manipulation of THz waves is another major issue. Here, freestanding and easily scalable composite film based on vanadium dioxide/carboxymethyl cellulose (VO2/CMC) is proposed to realize thermally and optically tunable THz waves. This VO2/CMC composite film exhibits broadband modulation with a modulation depth of up to 76%, a response time of about 1.2 s and high stability both in mechanical deformation and in air. Based on the above VO2/CMC composite film, a THz metamaterial with absorption-reflection switchability is demonstrated. By controlling the temperature-dependent phase transition of VO2 particles, the reflection dip of the metamaterial at 0.423 THz with an amplitude of -25 dB first shifts to lower frequencies accompanied by an increase in amplitude, and finally disappears with the THz metamaterial reflecting THz waves almost completely. The experimental results agree well with numerical simulations and the modulation mechanism of the metamaterial is also investigated. This work provides a simple and low-cost method for developing VO2-based THz multifunctional smart devices with promising applications in areas such as but not limited to THz modulators and sensors.
研究领域:
材料科学
·
光学工程
·
太赫兹技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2023
·Vol. 11
·期 39
·9525-9531
·
IF 7
Jie Li,Zhuang Ma,Anran Li,Siyuan Huang,Yufei Zhang,Yun Xue,Xianhui Song,Ye Zhang,Shihao Hong,Mo Wang,Zhongming Wu,Xinge Zhang
Microorganism adhesion and the resulting contamination of the biomaterial is one of the major causes of biomedical device failure. Stimuli-responsive materials based on dynamically regulating interactions with reversible characteristics of on–off states have attracted increasing attention. Here, a facile self-assembled biomaterial nanocoating constructed using acidity- and photoregulated spiropyran-modified nanoparticles was developed for reversibly regulating bacteria or mammalian cell adhesion-and-detachment. The coating was formed by coating a solution of spiropyran-conjugated nanoparticles around the surface of a silica gel followed by curing and drying at 60 °C for 30 min. Importantly, efficient adhesion-and-detachment of bacteria or cells could be controlled even after 8 cycles owing to the excellent acidity- and light-switched ability. Collectively, this well-defined self-assembled nanocoating as a dynamical and reversible agent provides promising insight for the development of biomedical devices, especially for biomaterial medical coatings.
研究领域:
生物材料学
·
表面工程
·
微生物学
·
再生医学
·
抗菌技术
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2024
·Vol. 12
·期 23
·2400839
·
IF 8
Xiao-Feng Wang,Rui-Lian Lin,Wen-Qi Sun,Jing-Xin Liu,Li-Xin Xu,Carl Redshaw,Xing Feng
Multistimuli-responsive color-changing materials have potential applications in areas such as chemical sensing and anti-counterfeiting. In this work, a fluoro-phenyl-acetyl-substituted viologen derivative (FPAV·Cl 2 ) is synthesized, which can form a supramolecular inclusion complex with cucurbit[7]uril (Q[7]) via self-assembly. Significantly, the resulting inclusion complex FPAV 2+ @Q[7] in the solid-state exhibits visual color changes in response to multiple external stimuli including light, heat, and vapors of ammonia and organic amines. The electron spin resonance (ESR) and ultraviolet–visible (UV–vis) spectra analysis reveals that the photochromic, thermochromic, and vapochromic behavior of FPAV 2+ @Q[7] is due to the generation of FPAV +• free radicals resulting from electron transfer. Furthermore, in the solid-state, FPAV 2+ @Q[7] shows controllable fluorescence regulated by its chromic process. Based on the multi stimuli-responsive color-changes and fluorescence properties of FPAV 2+ @Q[7], its practical applications in erasable inkless printing, multiple anti-counterfeiting processes, visible ammonia/organic amines detection, and information encryption are demonstrated. The supramolecular strategy of encapsulating viologen derivatives into macrocycles provides a general method for fabricating multi stimuli-responsive chromic materials with multiple practical applications.
研究领域:
超分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Advanced Science
·
2025
·
IF 14.1
Siwei Hu,Kexing Li,Weijia Nong,Zhong-Wen Liu,Zhao-Tie Liu,Yanhu Zhan,Jinqiang Jiang,Peng Yang,Guo Li
Magneto-driven soft robots featuring remote and highly permeable controllability are considered promising, especially in biomedical and engineering applications. However, there is still lack of a high-precision method to regulate the distribution of magnetic fillers in polymer substrates, which severely limits the improvement of the actuating functionality. This work provides a photo-regulatable method to develop soft robots with locally distributed magnetic Fe 3 O 4 nanoparticles. Solvent-casted polyvinyl alcohol/sodium carboxymethyl cellulose film is prepared as the substrate, and Fe 3+ ions are introduced to coordinate with carboxylate groups by surface treatment. Two processes, photo-reduction of Fe 3+ to Fe 2+ ions and the hydrolytic reaction of the two ions, are sequentially combined to in situ generate magnetic Fe 3 O 4 particles. Spatiotemporal control of UV light irradiation determines the Fe 3+ /Fe 2+ ratio and, therefore the amount of generated Fe 3 O 4 nanoparticles that decide magnetic field, NIR light, and moisture responsive actuating functionalities. Moreover, the external geometry of the composite can be tuned by inducing the formation of Al 3+ -carboxylate coordinates for strain retention, which enables shape programming of the composite to exhibit complex 3D–3D actuating behaviors. The proposed method enables the design and preparation of soft robots with spatially tunable magnetism and more advanced actuating behaviors.
研究领域:
材料科学
·
生物医学工程
·
机器人学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2024
·
IF 3.3
Yong-xing Liu,Decong Xie,Qing-ru Liu,Hu-wei Miao,Wei Liu,Li-li Li,Fa-yu Wu,Jing Zhu
An attempt was made to explore the relationship between the gas sensing performance of ZnSnO3 thin films and their intrinsic charge carrier behaviors. ZnSnO3 films with miscellaneous electrical characteristics were obtained by the combination of like-chemical oxygen control, fluorine doping, and like-physical light conditioning. The microstructure, morphology, optical transparency, electrical characteristics, and gas sensing performance were analyzed by X-ray diffraction, Raman spectroscopy, atomic force microscopy, ultraviolet spectrophotometer, Hall effect apparatus, and electrochemical testing system, respectively. The results show that through F–O coregulation, the carrier concentration of ZnSnO3 thin films was increased from 1017 to 1018 cm–3, the sensitivity was increased from 0.09 to 0.26, the response/recovery time was reduced from 165 s/153 s to 129 s/110 s, and the optimal operating temperature was lowered to 280 °C. The irradiation of simulating solar intentionally enhanced the carrier concentration, which significantly increased the sensitivity to 31.16 and greatly reduced the response/recovery time to 79 s/68 s. The minimum limit of detection concentration has been reduced to 2 ppm for dense and simple film, and even the minimum operating temperature has been drastically lowered to room temperature. For various derivated carriers with different concentrations, the mechanism of depletion and accumulation on the gas-sensitive response is proposed.
研究领域:
材料科学
·
传感器技术
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 5
·2673-2683
·
IF 2.302
Huang Zhangyu,Yi Mengji,Gao Huiping,Zhang Zhenlong,Mao Yanli
A strategy is demonstrated for simultaneous size and color tuning of KZnF 3 :Yb 3+ /Er 3+ nanocrystals through transition metal Mn 2+ doping. The experimental results indicate that the introduction of Mn 2+ into the KZnF 3 :Yb 3+ /Er 3+ reaction system facilitates the decrease of the crystal size. Moreover, in the case of a high concentration of Mn 2+ doping, the downshifting (DS) and upconversion (UC) luminescence all show a single red band emission. In this work, we mainly investigate the DS and UC energy transfer process among Mn 2+ /Yb 3+ /Er 3+ in KZnF 3 nanocrystals by the detection and analysis of the absorption, excitation, emission, and transient fluorescence spectra. The results show that both Mn 2+ and Yb 3+ ions can decrease the green emission while improving the red luminescence of Er 3+ . This DS and UC single red color tuning is significant for the application of nanoparticles in light conversion, biological labeling, or plant photosynthesis.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2022
·Vol. 9
·期 11
·2102251
·
IF 6.389
Xupeng Gao,Qiang Hu,Xin Li,Po Lu,Yuan Zhong,Xinyu Shen,William W. Yu,Min Lu,Zhennan Wu,Siyao Yu,Xue Bai,Yu Zhang
The dimension is a leading parameter in customization of unique optoelectronic properties of halide perovskite, while it is still challenging to achieve dimension control beyond the well-developed composition regulation-based strategy considering their intrinsic feature of ionic crystal. In this paper, ligands-directed confinement effect is emphasized in rendering the reduced-dimensional engineering of halide perovskite, and quasi-2D (OAm) 2 CsPb 2 Br 7 ( n = 2) nanosheets are obtained by introducing a large amount of metal ions. As a representation, with Mg 2+ participation, the initial adsorption of organic ligands (i.e., OA and OAm) to inorganic components (i.e., [PbBr 6 ] 4− ) is promoted, conferring a ligands-directed surface reconstruction to form the lamellar structure composed of alternate organic and inorganic layers. Namely, the inorganic–organic lamellar ensemble will play as a soft template, which effectively restricts the growth of [PbBr 6 ] 4− in the c -axis direction even after the Cs-OA injection, thus producing the anisotropic layered perovskite of (OAm) 2 CsPb 2 Br 7 from CsPbBr 3 scenario. Notably, such reduced-dimensional engineering enables a remarkable luminescence tailoring, of which the deep blue emission centered at 439 nm is achieved. In addition, benefiting from such universal strategy, the luminescence is also dependent on the species of introduced metal ions (e.g., Ca 2+ , Co 2+ , Sr 2+ , and Mn 2+ ).
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 19
·15577-15584
·
IF 3.289
Haixia Xuan,Xi Chen,Yinghui Wu,Kena Song,Yuenan Li,Ruchuan Liu
The impact of the nanostructures of conjugated polymers on their electronic properties is significant. We notice that poly(3-hexylthiophene-2,5-diyl) (P3HT) can form nano-islands and nano-fibrils, and both of them show an similar single-layer thickness (∼1.5–1.6 nm) as evaluated by atomic force microscopy (AFM). The Raman spectra indicate the highest degree of chain planarity and crystallinity in the nano-islands. By using scanning Kelvin probe microscopy (SKPM) and electrostatic force microscopy (EFM), we image the surface potential at the nanometer scale and quantitatively estimate the charges on these nanostructures as modulated by light. Both results are consistent with each other: the surface potential increases on switching on the light, and the photo-induced charges are around 15–25% and positive. A similar amount of the photo-induced charges in both P3HT islands and fibril is consistent with the π–π stacking nature of these nanostructures. As P3HT is a hole-conducting molecule, positive charges are found easily injected into a single island by a positively biased EFM tip, and then the injected charges are able to propagate all over the island.
研究领域:
材料科学
·
物理化学
✓ 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）