ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 32
·1902533
·
IF 15.621
Lingling Li,Ziyi Zhang,Ying Chen,Qin Xu,Jian-Rong Zhang,Zixuan Chen,Yun Chen,Jun-Jie Zhu
Lead halide perovskite quantum dots (QDs) are promising electrochemiluminescence (ECL) nanoemitters due to their fascinating photophysical properties. However, due to their poor structural stability against the external environment, the trade-off between their colloidal stability and carrier injection/transport efficiency is a major challenge in the advancement of perovskite-based ECL technology. In this work, intense and stable ECL from CsPbBr 3 (CPB) QDs is achieved by simultaneously encapsulating CPB QDs and coreactant (CoR) into in situ generated SiO 2 matrix via hydrolysis of tetramethyl orthosilicate. The well-designed architecture of the as-obtained CPB-CoR@SiO 2 nanocomposites (NCs) guarantees not only greatly improved stability thanks to the peripheral SiO 2 protecting matrix, but also efficient self-enhanced ECL between CPB and the intra-coreactants. Consequently, by elaborately selecting the CoR molecules with different tertiary/secondary amines and functional groups, multifold higher (up to 10.2 times) ECL efficiencies are obtained for the CPB-CoR@SiO 2 NCs alone in reference to the standard Ru(bpy) 3 2+ /tri- n -propylamine system. This work provides an efficient design strategy for obtaining stable and highly efficient ECL from perovskite QDs, and offers a new perspective for the development and application of perovskite-based ECL system.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
IEEE TRANSACTIONS ON ELECTRON DEVICES
·
2021
·Vol. 68
·期 4
·1738-1745
·
IF 2.917
Zong-Tao Li,Jie-Xin Li,Zi-Hao Deng,Jia-Yong Liang,Jia-Sheng Li
Quantum dots (QDs) are promising materials for various optoelectronic applications. However, the efficiency of QD white light-emitting diodes (QD-white-LEDs) is not at the desired level, particularly when the QD concentration in the silicone matrix is high and the corresponding mechanism has not been fully elucidated. In this study, we experimentally and theoretically investigated the aggregation-induced scattering (AIS) effect of QDs in silicone and unraveled the origin of low efficiency for QD-white-LED devices. Three-dimensional finite-difference time domain and ray tracing simulations were carried out to establish the AIS model for QDs. Results indicate that the AIS effect is stronger for higher QD concentrations and leads to a larger effective aggregate size (EAS), which was confirmed by comparing with the experimental results of QD-silicone films. Furthermore, we found that the AIS effect causes a significant reduction in the radiant efficiencies of QD-white-LEDs when the EAS exceeds 50 particles, which is validated by fabricated devices. According to the spectral energy analysis, the low efficiency of QD-white-LEDs can be attributed to a strong AIS effect at high QD concentrations, causing severe backscattering and reabsorption loss. This study is also important for nondestructive testing the degree of aggregation demonstrated by QDs in a silicone matrix and for precisely modeling QD-white-LEDs.
研究领域:
光学
·
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
TALANTA
·
2016
·
IF 4.035
Jian Li,Ning Zhang,Qingqing Sun,Zhanming Bai,Jianbin Zheng
A novel imprinted silica matrix-poly(aniline boronic acid) hybrid for electrochemical detection of dopamine (DA) was developed. Boronic acid functionalized conducting polymer was electrochemically prepared on Au electrode. The number of covalent binding sites toward DA templates was controlled by potential cycles. A precursory sol solution of ammonium fluorosilicate (as cross-linking monomer) containing DA was spin-coated on the polymer modified electrode . Under NH 3 atmosphere, the hydroxyl ions were generated in the solution and catalyzed the hydrolysis of fluorosilicate to form silica matrix. After this aqueous sol-gel process, an inorganic framework around the DA template was formed and the imprinted hybrid for DA was also produced. As revealed by scanning electron microscopy, UV-vis spectroscopy and cyclic voltammetry characterization, DA was embedded in the imprinted hybrid successfully. The affinity and selectivity of the imprinted hybrid were also characterized by cyclic voltammetry . The imprinted hybrid showed higher affinity for DA than that for epinephrine, and little or no affinity for ascorbic acid and uric acid due to the combined effects of covalent interaction, cavities matching and electrostatic repulsion. The imprinted hybrid sensor exhibited a quick response (within 5 min) to DA in the concentration range from 0.05 to 500 μmol L −1 with a detection limit of 0.018 μmol L −1 . The prepared sensor was also applied to detect DA in real samples with a satisfactory result.
研究领域:
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2013
·Vol. 69
·期 1
·130-136
·
IF 1.66
Xu Lianqiang,Huang Haifu,Tang Shaolong,Chen Leyi,Xie Ren,Xia Wenbin,Wei Jun,Zhong Wei,Du Youwei
In this work, we introduce a modified novel silica sol–gel process to synthesize hexagonal close-packed (hcp) and face-centered cubic (fcc) nickel (Ni) nanoparticles supported on amorphous carbon and silica matrix. The supporting of amorphous carbon and silica can prevent the Ni nanoparticles from aggregating and being oxided which would result in the loss of their magnetism and dispersibility. The phase structure of the Ni nanoparticles which were obtained from the gels pyrolyzed from 250 to 350 °C is hcp structure, whereas that of the Ni nanoparticles pyrolyzed at 750 °C is fcc structure. The grain sizes of the hcp Ni nanoparticles calcined at 250 °C range from 5 to 20 nm in diameter, and that of the fcc Ni nanoparticles calcined at 750 °C range in 7–35 nm. The studies of magnetic properties of the hcp and fcc Ni nanoparticles show that both have quite different magnetic behaviors.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Meng Xu,Zhenwei Wu
Mixed-mode reversed-phase/anion-exchange chromatography (RP/AEX) is an effective method for the chromatographic analysis of acidic drugs because it combines reversed-phase chromatography (RP) with anion-exchange chromatography (AEX). However, the result repeatability for the RP/AEX analysis of acidic drugs is frequently compromised by the detrimental effects of residual silanol groups in an RP/AEX stationary phase on peak separation and analyte retention. In this study, an RP/weak-AEX stationary phase with amino anion-exchange groups, Sil-AA, was prepared. Subsequently, an RP/strong-AEX stationary phase, Sil-PBQA, was prepared by replacing the amino groups in Sil-AA with a benzene ring and a benzyl-containing quaternary ammonium salt. The chromatographic behaviors of Sil-PBQA and Sil-AA were compared, and the effect of residual silanol groups on the chromatographic behavior of an RP/AEX stationary phase was evaluated. Residual silanol groups not only caused additional electrostatic interactions for acidic analytes, but also competed with the analytes for the anion-exchange sites in an RP/AEX stationary phase. The effects of different salt-containing mobile-phase systems on the analyte-retention behavior of Sil-PBQA were investigated to develop a method that enhanced the repeatability of the RP/AEX acidic-analyte-analysis results obtained using Sil-PBQA and facilitated the separation of nonsteroidal anti-inflammatory drugs on Sil-PBQA. The ideas presented in this paper can improve the separation of peaks and repeatability of results in the RP/AEX analysis of acidic drugs.
研究领域:
分析化学
·
药物分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Yali Yang,Jia Chen,Xiaojing Liang,Bei Liu,Kaijun Quan,Xiuhui Liu,Hongdeng Qiu
In this paper, three imidazole- and C18- bifunctional silica stationary phases (Sil-Im-C18) were prepared by adjusting introduction interval of octadecyltrichlorosilane (ODS) and 3-imidazol-1-ylpropyl(trimethoxy)silane (TMPImS), which can be used for reversed-phase liquid chromatography (RPLC) and ion exchange chromatography (IEC) with adjustable performance. The successful preparation of Sil-Im-C18 were confirmed by the characterizations of elemental analysis, infrared spectroscopy (FTIR) and contact angle (CA). Chromatographic performance of Sil-Im-C18 were evaluated by the separation of Tanaka test mixture, alkylbenzenes, linear PAHs and a set of analytes with different properties (uracil, phenol, 1,2-dinitrobenzene and naphthalene), and compared with commonly used C18 column. It was found that the chromatographic performance of Sil-Im-C18 changed significantly with the difference in bonding amount of imidazole and C18. Sil-Im-C18 demonstrated the excellent separation performance towards polycyclic aromatic hydrocarbons (PAHs), phenylesters, phenylamines , phenols and inorganic anions, and notably, nucleobases and nucleosides can be separated using pure water as mobile phases . The van Deemter plot showed that the column efficiency of Sil-Im-C18-3 was 64,933 plate· m − 1 for naphthalene, indicated that Sil-Im-C18 was reasonably chromatographic columns. The RSD values of retention time were 0.22 %-0.61 % for 10 needles alkylbenzenes injected continuously at 50 °C to investigate thermal stability and repeatability, all the fluctuations of k of naphthalene were less than 2.3 % for Sil-Im-C18-1 during flushing 24 h with the mobile phase at different pH values (pH = 3 and 8), the retention time of alkylbenzenes were almost same for Sil-Im-C18-1 at different time, the RSD values of retention time of alkylbenzenes were 0.45 %-2.28 % for two batches Sil-Im-C18-1, revealing the excellent repeatability, thermal stability, durability and reproducibility of Sil-Im-C18, and implying a commercial prospect.
研究领域:
分析化学
·
色谱技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 25
·e202301101
·
IF 2.1
Jiali Zhai,Huan Jiang
Graphical A novel solid-state fluorescent ZnO@SiO 2 nanocapsules powder with a fluorescence quantum yield of 26.8 % has been fabricated and successfully applied to fast latent fingerprint imaging. As advanced fingerprint powders, fluorescent materials generally provide high sensitivity and improved contrast on the pigments or patterned surface, with high resolution. In this study, ZnO nanoparticles are used as fluorescent materials and are homogeneously embedded into SiO 2 matrix to prepare ZnO@SiO 2 nanocapsules. Compared with conventional methods, ZnO@SiO 2 nanocapsules are fabricated using the transparent ethanol solution of ZnO NPs and n-Octyltriethoxysilane without any surfactants. Interestingly, a large number of ZnO NPs can be homogeneously embedded in the silica matrix, reducing the aggregation-induced quenching effect. The maximum emission of the ZnO@SiO 2 nanocapsules powder is located at 530 nm under 325 nm irradiation, and the photoluminescence intensity and the sensitivity of latent fingerprints development depend on the quantity of ZnO NPs in the composites. The prepared fluorescent ZnO@SiO 2 nanocapsules show outstanding property applied as effective fluorescent eikonogens for the high-sensitivity visualization of latent fingerprints on different porous and non-porous substrates. It has been demonstrated that ZnO@SiO 2 nanocapsules compounds combine the admirable adhesion of silica powders to fingerprint residues with the excellent photoluminescence properties of ZnO to form a promising light-emitting material for fingerprint.
研究领域:
材料科学
·
法医学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHROMATOGRAPHIA
·
2016
·Vol. 79
·期 21
·1437-1443
·
IF 1.332
Jiang Qiong,Zhao Wenjie,Qiu Hongdeng,Zhang Shusheng
In this study, octylbenzimidazolium-modified silica (BeImC8-Sil) was prepared by covalent attachment of 1-octylbenzimidazole to γ-chloropropyl silica. The synthesized materials were characterized by the elemental analysis, IR spectrum, and thermogravimetric analysis. Due to the introduction of phenyl and octyl groups on the quaternary imidazolium, the developed BeImC8-Sil column can function via both reversed-phase and anion-exchange retention mechanisms. The chromatographic properties of the synthesized material were investigated by the separations of polycyclic aromatic hydrocarbons, mono-substituted derivatives of benzene, anilines, and phenols, revealing the existence of multiple interactions, including hydrogen bonding, π–π stacking, electrostatic forces, and hydrophobic interactions in reversed-phase mode; inorganic and organic anions were also separated mainly through anion-exchange interaction. The proposed BeImC8-Sil is a promising mixed-mode stationary phase for the separation of complex samples in high-performance liquid chromatography.
研究领域:
分析化学
·
色谱技术
✓ 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）