Nano Energy
·
2017
·
IF 12.343
Nan Ma,Ya Yang
ABSTRCT Ferroelectric material BaTiO 3 (BTO) with intrinsic spontaneous polarization demonstrates excellent pyroelectric effect that output current/voltage signals can be observed even by slight temperature fluctuation. Here, we report a self-powered 365 nm UV light photodetector by using the light-induced pyroelectric effect in Ag/BTO/Ag device with the response time of about 0.5 s at the rising edge. Moreover, the heating-induced pyroelectric effect has been utilized to enhance the 365 nm light response, where both the corresponding photoconductive gain and responsivity can be dramatically enhanced by larger than 1200% under a temperature variation rate of 2.1 K/s as compared with that of UV light illumination. Our study proposes a feasible method to enhance the 365 nm light response by coupling light and heating-induced pyroelectric effect in BTO, which has potential applications in thermal energy scavenging and self-powered sensor systems .
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2024
·Vol. 26
·期 10
·1371-1379
·
IF 2.6
Meijuan Liu,Ying Chen,Xuegang Zheng,Haonan Zhao,Shusheng Pan,Zhiyu Liu,Dekang Xu,Hao Lin
In this study, a series of LiErF4:Tm@LiYF4:Yb,Er,Ce@LiYF4 core/shell/shell (C/S/S) UC nanoparticles (UCNPs) were prepared by a co-precipitation method. In this design of C/S/S structure, Er3+ is used as an energy collector in the first shell, which can reduce the energy loss by absorbing spontaneous emission from Yb3+. Then, by adding appropriate concentrations of Ce3+ into the same shell, the cross relaxation effect between Er3+ and Ce3+ is exploited to improve the efficiency of Er3+ in collecting the energy of spontaneous emission from Yb3+. During the upconversion (UC) process, Yb3+ plays a role as an energy transfer bridge, transferring the energy back to Er3+ in the core, thus enhancing the red UC emission intensity. Meanwhile, Tm3+ acts as an energy trapping center that contributes to the red emission. The results show that the spontaneous emission loss of Yb3+ has a certain effect on the UC fluorescence intensity, which will weaken the fluorescence to some extent, however is not the cause of the substantial decay of fluorescence. Therefore, this study provides clues for researchers to identify main factors affecting the luminescence efficiency, which will help develop more efficient UCNPs.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2016
·
IF 2.76
Liya Zeng,Yalin Zhang
The principles of formation and stability of nano-emulsions have been extensively investigated in previous research. In this study, we focus on the impact of short-chain alcohols (C < 5) on the formation and stability of oil-in-water nano-emulsions prepared by the spontaneous emulsification method. Due to its smaller droplet size and excellent optical transparency, the nano-emulsion stabilized by Cremophor EL was selected for further study. Addition of alcohol facilitated the nano-emulsion formation, moreover, the droplet size decreased with increasing alcohol chain length (C > 2) and hydroxyl groups. Nevertheless, the droplet size then increased further with the addition of alcohols, which we ascribed to the effect of alcohols on droplet flocculation. An optimum Cremophor EL-to-1-butanol ratio of 2:1 was employed to construct the ternary phase diagram. It was found that the fine droplets (r < 100 nm, PDI < 0.2) were obtained only when converting the initial oil drops completely into the lamellar liquid crystalline phase and/or bicontinuous phase and then this phase became supersaturated in oil, so that the nucleation of oil drops occurred spontaneously. According to the dynamic light scattering results, coalescence and Ostwald ripening were the main destabilization mechanisms in our systems. Notably, nano-emulsion stability was greatly improved with ethanol in comparison to 1-propanol and 1-butanol.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 32
·19815-19827
·
IF 3.108
Liya Zeng,Xin Xin,Yalin Zhang
Nanoemulsions have attracted much attention due to their wide application in commercial industries such as pharmaceutics, food, beverages and skin care. Cremophor EL has been extensively used for emulsification, protection and solubilization of various lipophilic bioactive agents. However, their anaphylactoid hypersensitivity reactions are still challenging. Therefore, the aim of this study was to develop and characterize a promising, low-level Cremophor EL-stabilized o/w nanoemulsion using the spontaneous emulsification method for oral administration. From comparing the physicochemical properties (particle size and size distribution) of their emulsions, Cremophor has better emulsifying capacity than Tween and the droplet radius of emulsions can be reduced by increasing the surfactant concentration in current systems. The impact of various short-chain alcohols (C–OH < 5) on the formation and stability of nanoemulsions was also investigated to optimize the formulations. And there is a good correlation between nanoemulsion droplet size and the surfactant packing parameter (p). The smallest droplet size with the narrowest size distribution was produced by the system containing ethylene glycol as a cosurfactant. However, preparation of nanoemulsions with ethylene glycol was a time-consuming process since it was difficult to emulsify the water-induced gel-structure. Surfactant-to-oil mass ratio and surfactant-to-cosurfactant levels had to be optimized to produce fine droplets. Moreover, there was a linear relationship between the viscosity/log P value of alcohols and droplet size. Ostwald ripening was the dominant breakdown process of nanoemulsions obtained in the ethyl oleate/Cremophor EL–butanol (3 : 2)/water system. Ostwald ripening rate was increased with increasing surfactant concentration. Dilution (100×) of this system considerably improved their stability against droplet growth. This study demonstrated that alcohol addition might be a useful tool for preparing Cremophor EL-stabilized nanoemulsions for pharmaceutical applications.
研究领域:
药剂学
·
化学工程
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生物医学工程
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DOI
高影响因子
LANGMUIR
·
2023
·
IF 3.9
Yuyi Zhang,Yuting Du,Qinghong Yuan,Chao Hang,Xiaolei Zhang,Bingwen Hu,Qingyuan Jin,Mengdi Chen
Enhancing the fluorescence of organic dye by colloidal particles is one of the most promising routes to optimize fluorescence detection. However, in addition to metallic particles, which serve as the most frequently used particles and have been found to employ the plasmonic resonance to provide strong fluorescence enhancement, neither new types of colloidal particles nor new fluorescence mechanisms have been intensively explored in recent years. In this work, strongly enhanced fluorescence was observed when 2-(2-hydroxyphenyl)-1H-benzimidazole (HPBI) molecules were simply mixed with zeolitic imidazolate framework-8 (ZIF-8) colloidal suspensions. Moreover, the enhancement factor ΔI = IHPBI+ZIF-8/IHPBI does not increase accordingly with the increasing amount of HPBI. To find out how the strong fluorescence was triggered and affected by the amount of HPBI, multiple techniques were applied to analyze the adsorption behavior. By combining analytical ultracentrifugation with first-principles calculations, we proposed that HPBI molecules were adsorbed onto the surface of ZIF-8 particles coordinatively and electrostatically, depending on the concentration of HPBI molecules. The coordinative adsorption would result in a new kind of fluorescence emitter. The new fluorescence emitters tend to distribute on the outer surface of ZIF-8 particles periodically. The distance between each fluorescence emitter is fixed and much smaller than the wavelength of the excitation light. Thus, it can be concluded that collective spontaneous emission might be triggered.
研究领域:
化学
·
材料科学
·
光学
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产品关联
DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 12
·2685
·
IF 2.8
Jian Zhu,Fei Wang,Shicheng Zhang,Xinfang Ma
Spontaneous imbibition (SI) effectively enhances oil recovery in shale reservoirs, significantly changing well shut-in and flowback design. This study conducted SI and displacement experiments to simulate the well shut-in and flowback stages so that the mechanism of imbibition and displacement between crude oil and fracture fluid can be discussed. In addition, the relative contribution to oil recovery of different types of pores in various stages and the effect of wettability were determined with low-field nuclear magnetic resonance (LF-NMR) via each sample’s T2transverse relaxation time at each time. The experimental results show that shale has multiscale pore structure characteristics combined with micropores, small mesopores, and mesopores. During the SI process, crude oil is displaced from micropores by fracture fluid at first, and then a large amount of oil production comes from small mesopores. Oil recovery of water-wet core samples is approximately 40.7%. Oil recovery of oil-wet core samples is about 26%. The wettability significantly affects the imbibition and displacement oil recovery of samples. For the process of SI, oil recovered from small mesopores takes the lead in the complete sample recovery. For the displacement process, oil recovered from small mesopores and mesopores take the lead in the complete sample recovery. After displacement, only 12% of fracture fluid flooded from the samples. This research, demonstrating the imbibition and displacement characteristics of terrestrial shale and several relevant affecting factors, contributes to understanding the fracturing fluid retention mechanism in shale reservoirs and provides crucial theoretical foundations for the development of shale oil reservoirs.
研究领域:
石油工程
·
地质学
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DOI
高影响因子
ACS Photonics
·
2018
·
IF 6.88
Pengqi Lu,Ruifeng Li,Ni Yao,Xusheng Dai,Zhenyu Ye,Kai Zheng,Weiguang Kong,Wei Fang,Shuang Li,Qinghua Xu,Huizhen Wu
Heavy-metal-free I–III–VI2 quantum dots (QDs) have recently emerged as favorable alternatives to toxic II–VI QDs for optoelectronic and biological applications, but low fluorescence efficiency is a key issue related to the promising nanocrystals. In this work, we demonstrate big enhancement of two-photon fluorescence efficiency and low threshold two-photon pumped amplification of spontaneous emission (ASE) of Zn-processed CuInS2 (CIS) QDs for the first time. The change of two-photon process caused by Zn2+ cation exchange in CIS QDs is systematically investigated. Two-photon ASE in Zn-processed CIS QDs films is achieved with a record of low threshold fluence of 5.7 μJ/cm2. With high two-photon fluorescence quantum yields and low threshold ASE, the Zn-processed CIS QDs could become a promising candidate for two-photon bioimaging, nonlinear optical and novel QDs laser devices.
研究领域:
材料科学
·
光学
·
生物成像
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 35
·12602-12609
·
IF 8.067
Chen Jia,Hongli Liu,Xiaoyuan Zhang,Shirong Wang,Xianggao Li
Self-powered photodetectors are great potential candidates in the next generation of low energy-consumption photoelectric devices. However, the planar-type metal–semiconductor–metal (MSM) self-powered photodetectors (PDs) of perovskites still suffer from poor photodetection performance. Herein, by taking advantage of the spontaneous polarization property of the CH3NH3PbI3 single crystal, which can generate an extra polarization electric field, planar-type self-powered Au/CH3NH3PbI3/Cu PDs with preferable photodetection capability is reported. The resultant PDs exhibit the maximum responsivity of 0.288 A W−1 in 400–840 nm under the superposed built-in electric field by spontaneous polarization and asymmetric Schottky junction. Furthermore, the maximum detectivity is 4.69 × 1012 Jones, which is the highest record among the planar-type MSM self-powered PDs based on a perovskite. Moreover, the PDs exhibited excellent operation stability with the photocurrent of the unencapsulated photodetector remaining at 92% after 15 days in atmospheric condition.
研究领域:
材料科学
·
光电子学
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产品关联
DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 6
·1205
·
IF 3.2
Qingsong Zhang,Huaqiang Sheng,Jinliang Li,Jinhu Li,Hao Zhang
In order to address the issue of wind leakage leading to spontaneous coal combustion in goafs during gob-side entry mining, a KH570 silane coupling agent (SCA)-modified vinyl acetate–ethylene (VAE)/cement-based flexible spraying sealing material was developed. The mechanical properties and wind leakage sealing performance of the material were evaluated using specialized testing equipment. Furthermore, molecular dynamics simulations and microstructural characterization techniques were utilized to assess and model the interface compatibility of the material. The experimental results demonstrate that KH570 significantly enhanced the material’s mechanical properties. Following modification, the material exhibited increases in the maximum tensile strength, compressive strength, and flexural strength by 53%, 38%, and 29%, respectively. KH570 not only promotes the formation of additional calcium silicate hydrate (C-S-H) gel through cement hydration, but also establishes Si-O-Si chemical bonds with cement hydration products and hydrogen bonds with the VAE emulsion. This functions as a “molecular bridge”, significantly enhancing the interface performance of the composite. The interaction between the organic and inorganic phases contributes to the formation of an interpenetrating network structure, imparting excellent compressive, flexural, and tensile deformation resistance to the material. The wind leakage of the spray-modified material was reduced by 2.7 times compared to the unmodified material, significantly improving its sealing performance under mining-induced pressure conditions. This enhancement effectively minimizes spontaneous combustion in mined-out coal areas caused by wind leakage, thereby ensuring safer mining operations.
研究领域:
材料科学
·
分子动力学
·
采矿工程
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DOI
PubMed
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Yanlin Guo,Chunhua Zhao,Xiaohan Wang,Zhenghe Xu,Dejun Sun
When propylene oxide/ethylene oxide (PO/EO) surfactants were initially placed in the oil phase, long-chain alkanes with poor water solubility were emulsified spontaneously upon contact with the aqueous phase. This formation of oil droplets under static conditions was monitored and the efficiency of spontaneous emulsification was quantified using multiple light scattering (MLS). The effect of the initial surfactant phase on the interfacial tension and moduli was investigated using an interfacial tensiometer. The utilization efficiency of the surfactant and energy under external energy inputs was compared by analyzing the droplet size of the emulsions using microscopic observation and dynamic light scattering. The surfactant with the highest efficiency of spontaneous emulsification could disperse crude oil, which was used to address crude oil spill incidents in cold marine environments. To the best of our knowledge, this is the first study to monitor spontaneous emulsification under static conditions using MLS. This spontaneous emulsification under static conditions depended on the spontaneous diffusion of the PO/EO surfactants from the oil phase into the aqueous phase and on their interactions with the oil molecules. The findings of this study provide insights into the application of MLS to monitoring spontaneous emulsification.
研究领域:
化学工程
·
材料科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yang Wang,Lina Zhou,Hui Li,Hailong Zhu,Teng Zhang,Menglun Yin,Qiuyue Xiang,Chen Hou
The photocatalytic (PC) degradation process of volatile organic compounds (VOCs) has been consistently restricted by the rapid recombination of photogenerated electrons and holes. To solve this problem, in this study, a novel photoelectrocatalytic (PEC) coupled system was constructed by integrating a single-chamber direct glucose fuel cell (SDGFC), which is capable of self-generating electricity, into the conventional PC system. The coupling system can inhibit the recombination of photogenerated electrons and holes by continuously generating a current without an applied power source. In addition, nitrogen-doped carbon quantum dots (N-CQDs) were prepared using biomass gelatin. This was employed as a PC material for the catalytic layer of the air cathode in the above coupling system, and the efficient degradation of benzene series (BTEX) was made easy by regulating the content of the N element. Notably, the N-CQDs under the optimal regulation ratio showed excellent optical properties and degradation performance, achieving an impressive PEC degradation rate of over 80 % for BTEX within 180 min. High-performance N-CQDs complement the novel PEC coupling system of self-generating electricity and provide robust support for BTEX degradation.
研究领域:
环境科学
·
材料科学
·
化学工程
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产品关联
DOI
高影响因子
iScience
·
2024
·
IF 4.6
Yang-Hui Luo,Xue-Ting Jin,Min Liu,Si-Wei Sun,Jie Zhao
Atmospheric water harvesting has emerged as an efficient strategy for addressing the global challenge of freshwater scarcity. However, the in being energy-consuming water-collecting process has obstructed its practicality. In this work, a soft drain bed, which was composed of hydrophilic cloth and hygroscopic gel, has been demonstrated to capture atmospheric water effectively, followed by converting it into liquid water spontaneously and sustainably, under all-weather humidity conditions. Under the optimal working condition of 30°C with a relative humidity level of 75%, the bed can provide a spontaneous water oozing ability of 1.25 g (liquid water) /hour within the 8 h of working time. More importantly, after 5 working cycles, 80% of the oozing ability can be reserved, suggesting the high potential for practical freshwater supply application. The proposed design strategy is expected to provide new hints for the development of future energy-saving decentralized freshwater supply systems.
研究领域:
环境科学
·
水资源管理
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）