DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 22
·7397-7405
·
IF 4.174
Jie Chen,Yixin Gao,Haifeng Jiang,Yan Liu,Zhaohui Jin
Optimizing structure and varying doped ions are two main strategies to obtain excellent luminescence performance. Spherical morphology is considered to be the most ideal phosphor structure due to the least surface defects. Herein, a series of spherical and monodispersed Dy3+/Eu3+ co-activated SiO2@Gd2O3 core–shell phosphors with multicolor tunable luminescence were successfully prepared via a facile urea assisted precipitation method. Related chemical reactions and the possible growth mechanism of Gd2O3:Ln3+ directional deposition on the surface of SiO2 microspheres were put forward. Upon 273 nm UV radiation excitation, SiO2@Gd2O3:Dy3+ and SiO2@Gd2O3:Eu3+ samples exhibited characteristic yellow (4F9/2–6H13/2) and blue (4F9/2–6H15/2) emissions of Dy3+ and red (5D0–7F2) emission of Eu3+, respectively. Meanwhile, multicolor emissions (warm white, yellow and orange) could be easily obtained by modulating the relative content of Dy3+ and Eu3+ in SiO2@Gd2O3:Ln3+ samples under a single excitation wavelength. Moreover, it was confirmed that Dy3+ could transfer energy to Eu3+ in the form of quadrupole–quadrupole interaction and further improved the luminescence intensity of Eu3+ by comparing experimental data with theoretical calculations. These results imply that tunable luminescence Dy3+,Eu3+ co-doped SiO2@Gd2O3 microspheres have great potential applications in multicolor displays and biolabeling fields.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2021
·
IF 8.528
Zixuan Lei,Jian Wang,Chi Zhang,Qianqiu Wu,Jian Li,Yuhong Liu
Simultaneously improving mechanical strength and toughness of thermosetting polymer nanocomposites remains a great challenge even though massive efforts have been made by controlling the aggregation and interface interaction of nanoparticles . In fact, crosslinking inhomogeneity and crosslinking density of thermosetting polymer nanocomposites can also profoundly affect the competing mechanical properties. Due to their conflicting influence on the toughness and strength of thermosetting polymer nanocomposites, the difficulty lies in how to coordinate the influence effectively. In this work, a mechanically tough and strong novolac phenolic nanocomposites (ESNH) were successfully constructed by introducing a reactive core-shell POSS with nanosilica as core and epoxy-polyhedral oligomeric silsesquioxane as shell (SiO 2 @EPOSS) (ES). Via controlling the quantity and the size of self-polymerized ES phase domain, the crosslinking inhomogeneity and crosslinking density of ESNH can be diversely tuned. Especially for 3%ESNH-3%, remarkably enhanced tensile properties and fracture toughness were realized. The self-polymerized ES phase domain with relatively small quantity and size was homogeneously grafted in phenolic networks, which could pin microstructural interfaces and junct nodular domains of phenolic networks, synergistically improving the crosslinking inhomogeneity and crosslinking density. Therefore, the moderately self-polymerized ES phase domain in the phenolic networks was remarkably contributed to coordinating the performance between the fracture toughness and tensile property. This study provides a novel and efficient envision toward simultaneously improving the toughness and strength of thermosetting polymer nanocomposites via tuning their curing behavior and the corresponding microstructure.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 97
·94976-94988
·
IF 3.289
Longfei Liao,Ying Liu,Zengyong Li,Junping Zhuang,Yanbin Zhou,Size Chen
Amino modified Fe3O4@SiO2 (Fe3O4@SiO2–NH2) was used to immobilize Cu2+ and VO2+ for preparing Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalysts. Various technologies had been used for the characteristics of catalysts, such as XRD, XPS, FT-IR, SEM, TEM and VSM. The catalytic performance of Fe3O4@SiO2–NH2–VO2+ in HMF oxidation could be significantly enhanced by the use of Fe3O4@SiO2–NH2–Cu2+ as the co-catalysts. The type of reaction solvents showed a great influence on the oxidation of HMF. The highest HMF conversion reached up to 98.7% at 110 °C in toluene with an optimal 2,5-diformylfuran yield of 85.5%. Moreover, the Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalyst exhibited great stability and could be readily applied in the next recycle after magnetic separation.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 111
·110409-110415
·
IF 3.289
Jin Dong,Baoping Lin
As an effective luminescent down-shifting (LDS) species, Eu3+ complexes have been doped in ethylene-vinyl acetate (EVA) films to improve the spectral response of silicon photovoltaic modules in the ultraviolet region. One key point about the improvement of photoelectric conversion efficiency by the LDS technique is increasing the fluorescence intensity of the EVA composite film as far as possible while staying within the visible light transmittance of the film. Around this point, we attempt to offer an idea for further studies. In this study, nano-SiO2 modified by a silane coupling agent was doped into EVA film with a fixed content of Eu3+ complex by the casting method. The experimental results show that when the modified SiO2 content is within 4%, the fluorescence of the EVA composite film gradually increases with increase in the modified SiO2 content and before formation of EVA composite film, the fluorescence intensities have no difference between the mixture with modified SiO2 and that without modified SiO2. SEM and AFM images of the EVA composite films show that the complex particles are probably enwrapped by aggregations of the modified SiO2 during the film-forming process, which strengthens the rigidity of the Eu3+ complex in the structure and results in the enhancement of fluorescence intensity. When the modified SiO2 content is within 2%, the visible light transmittance of the EVA film only slightly decreases. The photoelectric conversion efficiency of polycrystalline silicon solar cell coated with the composite film increases from 12.13% to 12.29%. Hence, the study provides a feasible approach to improve the LDS technique and has a potential application value.
研究领域:
材料科学
·
光伏技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 3
·1-12
·
IF 2.8
Huang Kai,Que Tao,Guo Xiang,Wang Rui,Ding Xiang,Zhou Hongqing
The advancement of high-density integration and packaging technologies necessitates the development of packaging materials that possess enhanced thermal conductivity and substantial mechanical strength. In this paper, we present a novel type of CaO–B 2 O 3 –SiO 2 /β-Si 3 N 4 composites synthesized through the solid-state reaction. The effects of β-Si 3 N 4 ceramic content on the sinterability, phase structure, microstructure, and properties of the composites were studied. As an excellent structural and functional material, the rod-like β-Si 3 N 4 ceramic not only enhanced the thermal conductivity (λ) and flexural strength of composite materials but also effectively reduced the thermal expansion coefficient (CTE) of the composite and maintained good high-frequency dielectric properties. The composite sample containing 15wt.% β-Si 3 N 4 demonstrated exceptional performance after sintering at 850 ℃ for 30 min, achieving a bulk density of 2.80 g/cm 3 , a relative permittivity of 6.52 with a dielectric loss of 1.94 × 10 –3 (15 GHz), a λ of 3.5 W/(m·K), a CTE value of 6.40 ppm/ ℃, and a flexural strength of 180.1 MPa. Additionally, the EDS line mapping indicates that there was no diffusion of silver at the interface, thereby affirming the favorable compatibility between the composite and the silver electrode. This characteristic positions the CBS/β-Si 3 N 4 composite as a potentially promising candidate for applications in electronic packaging.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Linxu Xu,Yaxin Li,Feiyong Chen,Xue Shen,Zhigang Yang,Jin Wang,Yufeng Du,Xinmeng Yue,Rupeng Liu,Yubo Zhao
In this paper, we present a simple way to achieve the controllable synthesis of composite ZnO@SiO 2 materials. γ-aminopropyltriethoxysilane (APTES) was chosen as the silicon source, and pre-synthesized zinc bromoacetate (ZnBA) was selected the functional metal precursor. By simply regulating the water–ethanol volume ratio, it was possible to simultaneously regulate the sizes of both the composite material and the metal nanoparticles . With an increase in the hydroalcoholic volume ratio from 1:1–3:1, the sizes of the silica materials were increased from 615 to 3020 nm, while the sizes of the ZnO nanoparticles were increased from 3.75 to 6.25 nm. Three ZnO@SiO 2 materials with blue, green, and yellow fluorescence were obtained. More importantly, the hydroalcoholic volume ratio and the particle size of the material showed a good linear relationship. In addition, a “rapid nucleation–aggregation growth” mechanism was proposed, and the controlled growth of metal oxide nanoparticles was explored.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Kun Wang,Wenxuan Lai,Deren Yang,Xuegong Yu
Optical physical unclonable functions (PUFs) present an innovative solution for verifying the authenticity of clinical biochips. However, achieving biocompatibility and minimizing interference with biochip accuracy remain critical challenges. Here, we report optical PUFs based on nanostructured silica (SiO2)/polydimethylsiloxane (PDMS) composite films. Amorphous SiO2 nanoparticles, synthesized via the sol–gel method, are randomly dispersed within the PDMS matrix through ultrasonication and spin-coating processes. The interplay between the disordered PDMS structure and the nonuniform distribution of SiO2 nanoparticles enhances the complexity of the Raman signals generated by the optical PUFs while ensuring biocompatibility and minimal interference with biochip accuracy. Furthermore, the efficacy of these optical PUFs is assessed by examining key performance metrics, including randomness, uniqueness, reproducibility, and encoding capacity. Additionally, the conceptual application of these optical PUFs for securing biochip supply chains is showcased, providing a robust solution to enhance the security of these critical devices.
研究领域:
材料科学
·
生物医学工程
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Fengfeng Chen,Kui Shen,Yitao Yang,Haigen Huang,Yingwei Li
The facile fabrication of porous solid acids is highly desired for replacing hazardous liquid acids for many acid-catalyzed reactions in the industry. Herein, we present a bottom-up strategy to construct ultrastable mesoporous Cr2O3/SiO2 nanohybrids (denoted as Meso-Cr–Si–O) with highly dispersed Lewis acid sites by pyrolysis of a SiO2@MIL-101 precursor prepared via nanocasting by a reverse double-solvent approach, which can guarantee the efficient encapsulation of SiO2 nanoparticles (NPs) inside the MIL-101 pores. The pore environment of Meso-Cr–Si–O can be well tuned by simply controlling the amount of silica within the MIL-101 pores and the pyrolysis temperature. Pyridine adsorption experiments demonstrate that the density of Lewis acidic sites in the obtained Meso-Cr–Si–O is much higher than that of MIL-101-derived Cr2O3 NPs. Benefitting from its highly mesoporous nanostructure with abundant acid sites, the optimal Meso-Cr–Si–O exhibits a significantly improved catalytic activity for the Lewis-acid-catalyzed Meerwein–Ponndorf–Verley reduction of cyclohexanone with 4.5 times higher yield of cyclohexanol than that of the MIL-101-derived Cr2O3 NPs, representing the first efficient Cr2O3-based catalytic system for this reaction.
研究领域:
化学
·
催化科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 15
·20104-20114
·
IF 2.478
Sun Junchen,Fang Min,Zhu Weiju,Wu Zhenyu,Li Cun
SiO 2 @TiO 2 -Ag (STA) microspheres decorated with Ag nanoparticles (Ag NPs) were prepared and assembled into the photoanode. The photoanode composed of STA microspheres and TiO 2 nanoparticles (P25) was prepared by doctor blade method. UV–vis measurement indicates that the introduction of a few STA microspheres observably enhances the light scattering and capturing ability of the photoanode. The photoelectric conversion efficiency of the DSSCs with 2wt% STA photoanode increased to 7.4% from 4.3% comparing with pure P25 TiO 2 nanoparticles. The configuration DSSCs have the maximum short circuit current density ( J sc ) of 16.0 mA cm −2 and open-circuit voltage ( V oc ) of 0.780 V, which are significantly higher than the pure TiO 2 DSSCs. The significant improvement of the DSSCs performance can be due to the synergistic effect of the superior light scattering of STA and the localized surface plasma resonance (LSPR) effect of Ag NPs modified on the microspheres surface.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2021
·Vol. 51
·期 1
·68-76
·
IF 1.938
Cui Xinying,Liu Li,Liu Xiaoyang,Li Yixin,Feng Yi,Ma Lijie,Liu Liangyu,Xue Ying,Zhu Yanchao,Wang Xiaofeng
Rice husks (RHs) are rich in silica and organic carbon components, which have been widely applied in lithium ion batteries. However, the natural structure of uneven dispersion between SiO 2 and amorphous C in RHs leads to poor electrical conductivity and structural integrity. In this work, SiO 2 /C composites were prepared by mechanical mixing and high-temperature carbonization from RHs, with coal tar electronic pitch (CTEP) or polyvinyl chloride (PVC) as the carbon coating agent, which imparted some improvement in cycling performance, initial coulombic efficiency (ICE), and rate performance. Compared with the high electrical conductivity of CTEP, PVC with low viscosity coated uniformly the surface of BM-SiO 2 /C, which is beneficial to providing both elastic and mechanical stability and keeping the structural integrity. BM-SiO 2 /C-PVC-6 exhibits a more stable cycling performance and higher specific capacity of 730 mA h g -1 after 100 cycles at 0.1 A g -1 , with the ICE of 60%. Hence, the application of carbon coating agent plays a vital role in improving the electrochemical performance of SiO 2 /C composites. PVC with excellent coating performance was selected to coat RHs-SiO 2 /C and the electrochemical performance was enhanced, which provides a method of converting biomass material into a useful storage device.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2023
·
IF 3.5
Yuting Wang,Chengyi Chu,Chenqi Duan,Jiajing Dong,Hao Chen,Songtao Ying,Jianjun Guo,Gaojie Xu,Fang Hu,Yuchuan Cheng,Aihua Sun
Due to aerogel's network structure, specific surface area, and high porosity, SiO 2 aerogel has excellent thermal insulation and inferior mechanical properties. It is challenging to produce micro-objects and complex-shaped objects accurately by traditional manufacturing method because of the fragile mechanical properties. Here, we use 3D printing to fabricate SiO 2 aerogels. At the same time, we add opacifiers to reduce the aerogel's medium-high temperature thermal conductivity. The thermal conductivity of the SiO 2 aerogel printed in the experiment is as low as 0.028 W/(m·K) at room temperature. The aerogel doped with 10 wt% SiC has the best thermal insulation at medium-high temperatures. And the 3D printed aerogel doped with 10 wt% SiC has a compression performance of 1.19 MPa, which is more than 10 times better than the usual aerogel. This paper provides a method for creating micro-objects and complex-shaped objects with excellent medium-high temperature thermal insulation using Direct Ink Writing (DIW).
研究领域:
材料科学
·
增材制造
·
热工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 10
·6334-6343
·
IF 1.134
Xie Cong,Zhao Yubin,Song Yuxiang,Liu Yingjie,Wang Yaya,Yang. Ping,Gao Guanggang
On the basis of maintaining the original characteristics of each component, the composite material obtains the properties that the single component does not have through the synergy between the components. It is of great significance to understand the synergy between the components
for the development of the composite. First of all, we prepared different emitting CdTe quantum dots (QDs), and then fabricated CdTe QDs@reduced graphene oxide (rGO) composites by a simple ultrasonic method. It is found that the fluorescence of QDs quenched, the photocurrent significantly
improved, but the growth rate different from each other because of the different QDs. Afterwards, on the basis of naked QDs, hybrid SiO2-coated QDs were fabricated by a two-step method. After that, hybrid SiO2-coated CdTe QDs@rGO composites were prepared by the same method.
It is found that the existence of the hybrid SiO2 shell leads to the decrease of photocurrent of the composites before and after coating, but the specific capacitance significantly improved, and the cycle stability also better than the naked QDs. This research will make grapheme-based
composites have broad application prospects in energy storage equipment.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）