LIQUID CRYSTALS
·
2020
·
IF 2.908
Tianwen Fan,Rongxin Shi,Huaying Tang,Hongyu Guo,Fafu Yang
This paper reported not only the first fluorescein liquid crystals but also revealed the influence of peripheral alkyl chains on mesomorphic properties and photophysical properties. Novel fluorescein-triphenylene dimers 4a–4f with different alkyl chains were designed and synthesised in yields of 76–83%. Samples 4a, 4b, 4c and 4d with CH3 and C4H9 exhibited the columnar mesophase but samples 4e and 4f with C8H17 showed no mesophase. The longer alkyl chains on fluorescein units resulted in the lower phase transition temperature. The too long alkyl chain destroyed the liquid crystalline behaviour. Their fluorescence quantum yields were as high as 0.78–0.87 in CH2Cl2 solution and 0.11–0.17 in solid states. The longer alkyl chains leaded to the higher emission efficiencies.
研究领域:
材料化学
·
物理化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Yanyun Zhu,Luting Yan,Mingyuan Xu,Yuting Li,Xiaodong Song,Lan Yin
Nitrogen-doped graphene quantum dots (N-GQDs) with prime fluorescence properties were synthesized through a simple one-pot hydrothermal method by using citric acid as carbon source and ammonia (A-GQDs) or urea (U-GQDs) as nitrogen source. Both A-GQDs and U-GQDs exhibited a graphene-like structure, but their average particle size is about ten times different. A-GQDs exhibited an evident excitation-dependent photoluminescence (PL) behavior. By contrast, the emission of U-GQDs can be divided into two regions with the development of excitation wavelength: a wavelength-independent emission peak at approximately 540 nm (green) with the excitation wavelength from 400 nm to 500 nm and an excitation-dependent emission peak with the excitation wavelength below 400 nm. Ammonia was introduced into citric acid polycondensator in the form of five membered ring and urea in the form of seven membered ring, respectively, which further affected the subsequent crystallization and surface functionalization. At this time, the structural instability of the nitrogen-containing doped ring itself, coupled with the progress of carbonization, mostly forms a stable nitrogen-containing ring structure, which is likely to be pyrrolic nitrogen or graphitized nitrogen. Therefore, the differences in particle size and nitrogen-containing doped rings partially between A-GQDs and U-GQDs lead to the differences in optical properties. Finally, U-GQDs with high quantum yield (QY) of 54 % were obtained at the molar ratio of 9:10 (citric acid/urea) by optimizing the reaction conditions.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Shenghong Yang,Ke Wang,Xin Wang,Xiaohan Sun
In-depth research on surface functionalization of carbon dots (CDs) has opened new horizons for their application in chemosensing and biosensing. However, the practicability of CDs is still limited due to their unmanageable fluorescence properties. In this study, organic acid was employed to regulate and control the fluorescence performance of CDs. A remarkable enhancement of fluorescence and redshift of the fluorescent band of CDs was observed via organic acids’ participation in the water phase preparation process. Furthermore, a colorimetric and fluorescent dual-readout strategy was constructed for the analysis of copper ions (Cu 2+ ) based on ethylenediaminetetraacetic acid (EDTA)-regulated carbon dots. The proposed sensing system can be used in the fast detection of Cu 2+ via an obvious solution color change from yellow to brown under natural light, and the trace analysis of Cu 2+ can be realized by quenching the green fluorescence band with detection limit of 21 nM. The designed sensor has been employed to the analysis of Cu 2+ in water and urine samples successfully, and cell imaging experiment was performed to evaluate the feasibility of biomedical applications.
研究领域:
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Zhixiong Hu,Xin-Yue Jiao,Li Xu
The green tea leaf residue was used as the carbon source to produce carbon dots (named as T-CDs) by combining pyrolyzation at high temperature and oxidation by concentrated H 2 SO 4 . Owing to the co-doping of S and N, T-CDs possessed high fluorescence quantum yield up to 14.8%. The fluorescence of the T-CDs was stable to the environmental pH, ionic strength and ultraviolet radiation, but sensitive to temperature with switchable intensity between 15 °C and 65 °C. The fluorescence of T-CDs was also found to be quenched by gefitinib via the inner-filter effect. Thus, T-CDs were used as the fluorescence sensor for gefitinib determination with good linearity in the range of 0.1 μg/mL to 20 μg/mL with satisfactory accuracy. The proposed T-CDs were obtained based on waste recycling of tea leaf residue for sustainability, and this strategy widened the applications of CDs.
研究领域:
材料科学
·
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2021
·
IF 4.889
Xiaofeng Sun,Hui Wang,Jinpeng Qi,Shengju Zhou,Hongguang Li
In recent years, it is heartening to witness that carbon dots (CDs), a rising star in the family of carbon nanomaterials , have displayed tremendous applications. However, the investigations toward self-assembly of CDs are still in their infancy. Tannic acid (TA) is a naturally derived polyphenolic compound with special molecular structure. Here, the co-assembly of CDs and TA in aqueous solutions has been investigated. The CDs/TA binary mixtures exhibited rich phase behavior, which went through the process of transparent phase-turbid phase-transparent phase. We focus on investigating the morphologies of the samples. As the concentration of TA increases, the aggregates evolve from the network structures to the spherical aggregates, and finally become the vesicles. Through systemic analysis of changes of zeta potential , morphologies and size distributions at varying temperature and pH, the mechanism of aggregate formation is proposed. The effect of adding TA on the fluorescence properties of CDs aqueous solutions was studied. After integration into aggregates, the potential applications of the CDs in biology and life sciences could be significantly expanded.
研究领域:
材料科学
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2015
·
IF 2.012
Yan Xie,Junjie He,Tingting Wang,Heping Zeng
Reactions of Zn(II) salts, 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and 2-mercaptobenzoic acid or 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H3PrIDC), result in two mixed-ligand coordination polymers (CPs), [Zn2(IPT)(DSDB)(OH)]n (H2DSDB = 2,2′-disulfanediyldibenzoic acid, 1) and [Zn2(IPT)(PrIDC)(H2O)]n (H3PrIDC = 2-propyl-1H-imidazole-4,5-dicarboxylic acid, 2). Compound 1 possesses a 2-D structure built by 1-D [Zn(IPT)]n chains and DSDB2− connectors, in which the DSDB2− is generated via in situ reaction from 2-mercaptobenzoic acid. It displays a new intricate 4-nodal {3·4·6·7·8·9}{3·6·7·8·9·10}{3·8·9}{4·6·8} topology. Compound 2 displays a 3-D framework with new 3-connected topology with Schläfli symbol of (4·8·10) (8·122), in which the 1-D Zn-carboxylate chains were bridged by 3-connected IPT− ligands. The thermal stabilities and luminescence properties of 1 and 2 have also been studied. The compounds exhibit intense solid-state fluorescent emissions at room temperature.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Qiangwang Geng,Chong Zhang,Kaiwen Zheng,Junying Zhang,Jue Cheng,Wei Yang
Hydrogels are smart materials with a high moisture content, elasticity, and stimuli to pH and temperature and are widely used in drug delivery, wound dressings, tissue engineering, parting materials, and sensors. However, a hydrogel with a multiresponsive feature is desired and challenging to produce. Here, a novel multiresponsive color-change hydrogel, including pH response, light response, and alcohol response, was successfully fabricated by introducing Michler’s hydrol blue (MHB) into a semicrystalline hydrophobically associated hydrogel. The color-change function is obtained by a transformation between MHB and protonated Michler’s hydrol blue (PMHB) deduced by nucleophilic attack processes. An excellent swelling performance of 2010% of the hydrogel was confirmed by swelling, time-dependent rewetting data, and differential scanning calorimetry (DSC) measurements. Its color change was obvious and fast, within 1 min, when exposed to ultraviolet (UV) light, alcohol, or pH change. In addition, the tensile strength of the hydrogel reached up to 0.9 MPa with loading MHB by 2.0%. The fluorescence and self-healing performances were verified to be good due to the presence of a large delocalized π-bond and hydrogen bonds. This material fabricated by a facile process might have potential applications in visual fluorescence sensors.
研究领域:
材料科学
·
生物医学工程
·
化学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Xue-Zhen Zhang,Xiao-Feng Wang,Wei-Hui Fang,Jian Zhang
Aluminum is an important component for luminescence. However, the fluorescent aluminum complex with unambiguous structural information is still limited. Herein, we report a series of fluorescence aluminum oxo clusters (AlOCs). By introducing an additional coordination site to the aromatic conjugation ligand, cluster nuclearity increment and fluorescence variation are observed. Al8(OH)2(μ4-O)2(1-NA)2(OEt)16 (AlOC-41, 1-NA = 1-naphthoic acid, OEt = ethanol) is made up of two tetrahedral subunits. By introducing an additional coordination site to the aromatic conjugation ligand, we isolate a high nuclearity compound Al10(μ3-O)2(3-HNA)2(OEt)22 (AlOC-47, 3-HNA = 3-hydroxy-2-naphthoic acid). Correspondingly, their luminescence performance is different (blue fluorescence in AlOC-41 and green in AlOC-47). Present herein is a platform to illustrate the relationship between synthesis, structure, and fluorescence properties.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
INTEGRATED FERROELECTRICS
·
2021
·
IF 0.836
Peisong Tang,Xuezhi Wei,Liqin Zhang,Ruipeng Hou,Yifan Zhou
Using Eu2O3 as source of tritium, anhydrous ethanol as solvent system, three β-diketone compounds of 2-thienyl trifluoroacetone (TTA), acetylacetone (Hacac), 1-(4-Methoxyphenyl)- 3-(4-tert-butylphenyl)-1,3-propanedione (Avobenzone) as first ligand and 1,10-phenanthroline (Phen) as second ligand, the three kinds europium (III) ternary complexes were prepared by precipitation method at 60 °C. The complexes were characterized by fluorescence spectroscopy (FS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry and differential scanning calorimetry (TG-DSC) and color coordinates. The results show that three red light-emitting europium (III) ternary complexes can emit strong red characteristic fluorescence. Thereinto, Eu(TTA)3Phen has the best luminescent performance. The excitation spectrum of Eu(TTA)3Phen is 395 nm, the characteristic emission peak is at 612 nm, and the color coordinate is (0.66, 0.34). Eu(TTA)3Phen show good thermal stability which is decomposed more than 200 °C.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 30
·13118-13124
·
IF 3.288
Long Chen,Yang Wu,Heyong Huo,Bin Tang,Yuhua Fu,Xiujie Hu,Chenghua Sun,Shuyun Zhou
Rare-earth phosphor materials have been investigated for several decades due to their high X-ray absorption coefficient and emission efficiency, but these materials tend to reveal lower resolution and packing density when fabricated in bulk. In this work, we investigated the BaFBr:Eu2+ micro/submicro/nano-crystal phosphor material prepared using a precipitation method, and we demonstrate the dependence of the optical properties of these phosphors on the annealing temperature and Eu2+ concentration. The optimum preparation conditions were determined to be an annealing temperature of 600 °C for 2 h and an Eu2+ doping concentration of 0.1 mol%, achieving a quantum yield of 53.19%. Furthermore, the average lifetime is 669 ns. In comparison with typical bulk phosphors, the shape and size distribution of the crystallites, which is about 100 nm on average, may improve the resolution and enhance the fluorescence performance. The results of this study thus offer a new strategy for the development of highly efficient storage phosphors.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Applied Materials Today
·
2021
·
IF 10.041
Minghao Ni,Ming Gong,Xiang Li,Jinlou Gu,Bo Li,Ye Chen
Metal-organic frameworks (MOFs) have attracted significant attention thanks to their excellent physical and chemical properties. Metal-organic frames are widely used in optics. For example, metal-organic frameworks can be used in fluorescent probes to detect and treat diseases, and can also be used to make solid-state light-emitting devices. Considering the high stability and easy synthesis of Zr-based UiO-66 MOF as well as the strong fluorescent emission of porphyrin molecules, the TCPP-incorporated UiO frameworks would inherit these advantages and exhibit intriguing optical performance. Therefore, in this paper, TCPP was doped into UiO-66, and the optical properties of the resulting MOF structure were observed. To obtain the optimal doping condition, three doping concentrations of TCPP were used. Besides the structural and morphological characterization by X-ray diffraction and scanning electron microscopy, more attentions have paid on the optical testing based on absorption and fluorescence spectroscopy, two-photon fluorescence spectroscopy and time-resolved spectroscopy. As a result, the TCPP-doped MOFs exhibited good fluorescence properties and satisfied our previous expectations of nonlinear optical properties and two-photon absorption. This work would pave a new way in constructing various MOFs-based solid-state devices with widespread optical applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2018
·
IF 2.732
Yong Kuai,Changchang Zhang,Dule Hao,Xiang Liu,Liang Ma
Organic amines are apt to be oxidized in natural environment. Therefore, preparation of fluorescent materials derived from organic amines should think of the role of oxidized amines. However, this is neglected according to some reports. Herein, first generation poly(amidoamine) ( PAMAM 1.0G ) dendrimers with inherent weak photoluminescence was oxidized by ambient oxygen under heating of 180 °C for 60 min which brought an obvious enhancement of fluorescent quantum yield (QY). The oxidation was proved by both infrared and 1 H nuclear magnetic resonance. Image of transmission electron microscope (TEM) also revealed the aggregation of PAMAM 1.0G after they were suffered from the lasting heating. The enhancement of QY was also observed when the mixture of aqueous solution of PAMAM 1.0G and citric acid were disposed under the same conditions. And the QY reached as high as 64.40%, which is much higher than that of the fluorescent materials derived from sole citric acid. TEM image also exhibited the aggregation of the product. The carboxyl of the aggregated particle could be activated by N-hydroxysuccinimide and could be bonded with bovine serum albumin realizing the fluorescent labeling of BSA finally, which was demonstrated by the image of gel electrophoresis .
研究领域:
材料科学
·
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）