JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 9
·5478-5485
·
IF 1.134
Xie Cong,Zhao Yubin,Song Yuxiang,Liu Yingjie,Wang Yaya,Yang Ping
Compared with conventional semiconductor quantum dots, hybrid SiO2 coated CdTe QDs exhibited high stability, long fluorescent lifetime, high photoluminescence quantum yields, and well biocompatibility. In this paper, CdTe QDs with tunable PL from green to red emitting were
prepared by an aqueous synthesis. A sol–gel process resulted in CdTe QDs coated with a hybrid SiO2 shell contained CdS-like clusters to obtain red-shifted PL spectra, increased PL efficiency and high stability. The clusters were formed by the reaction of Cd2+ and
S2− ions generated via the decomposition of thioglycolic acid. The clusters around CdTe cores created a core–shell structure which is very similar with traditional semiconductor core–shell QDs. After being coated with a hybrid SiO2 shell, the PL of green-emitting
naked CdTe QDs was red-shifted largely (~30 nm) while the PL of yellowemitting CdTe QDs revealed a small red-shifted (~20 nm). Furthermore, The PL of red-emitting naked CdTe QDs was red-shifted much small (less than 10 nm). This phenomenon is ascribed to the change of band gap of CdTe cores
with sizes. The red-shift of PL spectra is attributed to the CdS-like clusters around the core rather than the thickness of the hybrid SiO2 shell.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2016
·Vol. 18
·期 2
·1-11
·
IF 2.101
Du Yingying,Yang Ping,Matras-Postolek Katarzyna,Wang Junpeng,Che Quande,Cao Yongqiang,Ma Qian
A silanization process was employed to transfer hydrophobic quantum dots (QDs) prepared via an organic route at high temperature into water phase. The QDs were further coated with a thin organic SiO 2 shell to form QDs@SiO 2 composite nanoparticles by ligand exchange or remaining initial organic ligands on the surface. In this study, QDs with different ligands, either trioctylphosphine oxide (TOPO) or oleic acid (OA), were employed to investigate the effects of ligands on the reverse micelles in preparing QDs@SiO 2 nanoparticles. In the preparing process, hydrophobic QDs were silanized by partially hydrolyzed tetraethyl orthosilicate (TEOS). For TOPO-capped CdSe QDs, surface TOPO ligands were completely replaced by partially hydrolyzed TEOS. As for OA-capped CdSe/Cd
x
Zn 1− x
S QDs, surface OA ligands were partially replaced. It was found that the ligand exchange drastically reduced the photoluminescence (PL) efficiency of CdSe QDs. Furthermore, the cytotoxicity studies of QDs@SiO 2 have been carried out in detail. The results indicate that CdSe/Cd
x
Zn 1− x
S QDs@SiO 2 composite nanoparticles exhibit lower cytotoxicity compared with CdSe QDs@SiO 2 , because the SiO 2 shell and remained OA ligand layer can effectively prevent the leakage of toxic Cd 2+ ions. Meanwhile, it was found that these CdSe/Cd
x
Zn 1− x
S QDs@SiO 2 nanocomposites could keep excellent PL properties even for 24 h incubating with Siha cells, which indicating that our prepared composite nanoparticles are potentially applicable for cell imaging in biological systems.
研究领域:
生物医学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2012
·
IF 1.856
Zhanwang Zhu,Xinlin Wei,Feng Xu,Yuanfeng Wang
The thermal decomposition approach, reverse micro-emulsion system and surface modification technique had been successfully used to synthesis single magnetic core Fe 3 O 4 @Organic Layer@SiO 2 –NH 2 complex microspheres . The magnetization of the magnetic microspheres core could be easily tuned between 28 and 56 emu/g by adjusting the amount of 2-mercaptobarbituric acid. It was found that the Organic Layer to some extent had a protective effect on avoiding Fe 3 O 4 being oxidized into Fe 2 O 3 . Each Fe 3 O 4 @Organic Layer microsphere could be coated uniformly by about 30 nm of silica shell. The average diameter of the Fe 3 O 4 @Organic Layer@SiO 2 composites was about 538 nm. The saturation magnetization of the Fe 3 O 4 @Organic Layer@SiO 2 complex microspheres was 12.5% less than magnetic microspheres cores. The Fe 3 O 4 @Organic Layer@SiO 2 –NH 2 composites possessed a huge application potentiality in specificity enriching and separating biological samples.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2024
·Vol. 35
·期 23
·235301
·
IF 2.9
Huan Yang,Xinbing Jiang,Manman Zhang,Ben Q Li,Jiajie Wang,Yiping Han
We report a structure of silicon eccentric shell particles array, fabricated by the SiO2 particles monolayer array assisted deposition of amorphous Si, for high-efficiency light confinement. The SiO2 particles monolayer array is tailored to regulate its interparticle distance, followed by silicon film deposition to obtain silicon eccentric shell arrays with positive and negative off-center distance e. We studied the Mie resonances of silicon solid sphere, concentric shell, eccentric shell and observed that the eccentric shell with positive off-center e supports superior light confinement because of the enhanced Mie magnetic resonances. Spectroscopic measurements and finite difference time domain simulations were conducted to examine the optical performance of the eccentric shell particles array. Results show that the Mie magnetic resonance wavelength can be easily regulated by the size of the inner void of the silicon shell to realize tunable enhanced light confinement. It was found silicon shell with D = 460/520 nm offered high enhanced light absorption efficiency at wavelength of λ = 830 nm, almost beyond the bandgap of the amorphous silicon.
研究领域:
纳米材料
·
光学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
·
2024
·
IF 2.8
Shi-Yu Ma,Jin-Kai Li,Zong-Ming Liu
In this paper, CsPbX 3 @SiO 2 (X = Cl, Br) with cubic morphology and stable optical properties have been developed. The average thickness of the SiO 2 shell is 2 ∼ 6 nm, which has the effect of protecting CsPbX 3 and isolating the external environment, passivating the surface and reducing the defect density, thus greatly improving the stability of CsPbX 3 PQDs. Based on this, the advantages of APTES as a preparation system CsPbX 3 @SiO 2 is revealed, the mechanism diagram is drawn and the stability improvement mechanism CsPbX 3 @SiO 2 is analyzed in detail, which provides a new idea for the stability improvement of CsPbX 3 perovskite quantum dots.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Technologies
·
2022
·Vol. 8
·期 4
·2201231
·
IF 8.856
Mingdeng Huang,Weiguang Lin,Yisimayili Tuersun,Xu Huang,Sheng Chu
Room-temperature liquid metals, such as galinstan, have become an emerging material in electronics requiring stretchability and deformability due to its excellent fluidity and conductivity. Eutectic gallium-indium-tin (galinstan)-based composites with certain metallic fillers can obtain magnetism. However, the alloying reaction between galinstan and metals leads to the solidification and reduction in stability of the composite. In this study, Ni@SiO 2 nanoparticles with the core–shell structure are used as fillers and galinstan as matrix. The obtained galinstan-Ni@SiO 2 paste is fairly stable and this is attributed to the silica shell, which acts as a barrier to isolate the direct contact between the Ni and galinstan. In addition, flexible circuits composed of as-prepared galinstan-Ni@SiO 2 pastes are fabricated, which exhibited outstanding durability, retrievability, and self-healing ability under the drive of magnetic field.
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 CLUSTER SCIENCE
·
2022
·Vol. 34
·期 1
·547-556
·
IF 3.447
Mo Songping,Shan Shaofei,He Lijuan,Jia Lisi,Chen Ying
Nanoencapsulation can effectively protect phase change material (PCM) from the ambient. Sugar alcohols have great potential for thermal energy storage. However, base or acid used in the most popular encapsulation methods may damage the PCM core. In this study, binary sugar alcohols of D-mannitol (DM) and inositol (IN) were first nanoencapsulated at neutral pH conditions. Nanocapsules with silica as the shell and different DM/IN ratios of 4.0:1, 4.6:1 and 5.5:1 were synthesized at different precursor ratios of tetraethoxysilane to triethoxysilane of 8:6, 9:5, and 10:4. The nanoencapsulation was demonstrated by scanning electron microscope (SEM), transmission electron microscope, energy-dispersive X-ray spectrometry, and Fourier transform infrared spectrometer. The phase change characteristics, thermal energy storage-release performance and thermal stability of the nanocapsules were studied by differential scanning calorimeter, thermal energy storage-release experiments, SEM, thermo-gravimetric analyzer (TGA) and thermal cycling tests. Results show that the phase change characteristics and thermal energy storage-release performance of the nanocapsules varied with the DM/IN mixing ratio and ratios of precursors. The DM/IN-4.6:1-9:5@SiO 2 nanocapsules exhibited the best phase change characteristics and thermal energy storage-release performance. Thermal stability of the nanocapsules was improved compared to pure binary sugar alcohols.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2014
·Vol. 2
·期 19
·3812-3819
·
IF 0
Yijie Zhou,Shidong Ji,Yamei Li,Yanfeng Gao,Hongjie Luo,Ping Jin
Microemulsion technology was introduced to prepare V1−xWxO2@SiO2 core–shell nanostructures with various morphologies (nanorod, nanosphere, and their combination) by controlling the pH of the microemulsion. Flexible foils coated with the core–shell nanoparticles exhibited high optical performance with solar regulation efficiencies up to 12.55, 14.17, and 12.90% and fairly high visible transmittance of 53.20, 45.26 and 39.41 for 0 at%, 1 at%, and 2 at% of W-doped VO2 particles, respectively. The results suggested that the current foil was very suitable for application in smart windows. Interestingly, W doping did not deteriorate the solar regulation ability, which has not been reported before. The SiO2 shell played multifunctional roles because it can not only depress the aggregation and secondary growth of the nanoparticles during the process of annealing but also obviously enhance the thermal stability of V1−xWxO2. The amazing results provide significant progress in VO2-based thermochromic coating with a Mott phase transition temperature near room temperature and pave the way for practical application to smart windows.
研究领域:
材料科学
·
纳米技术
·
能源与环境
✓ 已验证
DOI
RSC Advances
·
2016
·Vol. 6
·期 37
·30852-30861
·
IF 3.289
Fu Yang,Saifu Long,Shijian Zhou,Xiaoming Li,Xianfeng Liu,Shuying Gao,Yan Kong
A dispersed and stable catalytic active phase and a protective reaction environment are acknowledged as ideal metal catalyst characteristics. In this paper, a cores@shell structure of microreactor with a well-dispersed active phase of multiple free-Ag-cores, hollow cavity and protective mesoporous shell was prepared by a simple and novel construction approach. The organic ligand of aminosilane (APTES) was directly incorporated on carbon nanospheres to anchor Ag ions as a metallotemplate, which avoids the tedious steps of conventional methods, and then the sacrificed metallotemplate was employed for directly fabricating the special hollow mesoporous silica microreactors. As a result, multiple free active Ag-cores were in situ produced and encapsulated in the cavity of hollow mesoporous silica during the thermal process. The important evidence of the configuration including a big hollow cavity containing active multiple-Ag nanoparticles and a mesoporous SiO2-shell can be demonstrated with efficient techniques including XRD, FT-IR, XPS, BET, SEM and TEM. Just as expected, the catalyst as a functional microreactor exhibited a high catalytic activity for the liquid-reduction of 4-nitrophenol, and the increasing dosage of used catalyst contributes to the enhancing of catalytic activity. The methodology demonstrated here provides a new insight for the fabrication of versatile functional nanomaterials with noble or transition metals inside a hollow shell.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Geoenergy Science and Engineering
·
2024
·
IF 0
Yue Sun,Chengxi Deng,Hua Dong
In this work, hydrophobic/oleophilic cellulose/SiO 2 aerogels are prepared by coating cellulose aerogels which are prepared from freeze-drying aqueous cellulose solutions with a layer of silica shell and then hydrophobizing the surface by reacting with vaporized methyltrimethoxylsilane. With the cellulose content in the aqueous solution increases from 0.5% to 1.25%, the density of the cellulose/SiO 2 aerogel increases from 28.92 mg/cm 3 to 34.83 mg/cm 3 , and the porosity decreases from 90.2% to 84.48%. The structure and composition of cellulose/SiO 2 aerogel are analyzed with SEM, FT-IR, XPS , and TGA . The surface wettability investigation indicates that the prepared cellulose/SiO 2 aerogels have excellent hydrophobicity and oleophilicity, with a water contact angle up to 143° and an oil contact angle down to 0°. The results of oil absorption experiments show that the absorption capacity of the aerogels for oils and organic solvents is 16∼40 times their own mass. In addition, as the aerogels are hydrophobic/oleophilic, they demonstrate good oil-selective absorption performance in oil/water mixture. Moreover, experimental results in oil absorption under high temperature conditions and acidic/basic conditions indicate that the aerogels have exceptional resilience towards arduous conditions. These advantages render them a viable option for remediation of water pollution resulted from oil contamination.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
Advanced Healthcare Materials
·
2017
·Vol. 7
·期 4
·1700816
·
IF 5.11
Qiang Yang,Huali Chen,Yan Bai,Yang Cao,Wenjing Hu,Liangke Zhang
A novel organic/inorganic hybrid nanovesicle as an ultrasound imaging agent is synthesized via facile emulsion and silica deposition methods. This nanovesicle, hyaluronate (HA)–docetaxel (DTX)/perfluoro- n -pentane (PFP)@SNC, consists of an encapsulated liquid PFP core, loaded DTX, and an HA-decorated silica shell. The HA–DTX/PFP@SNC has a narrow size distribution of 274.5 ± 3.25 nm, a negative zeta potential of −11.6 ± 0.47 mV, and an entrapment efficiency of 86.70% ± 1.42%. HA–DTX/PFP@SNC possesses an ultrasound (US)-triggered drug release and a temperature-dependent size change behavior. Compared with DTX/PFP@soybean phosphatidylcholine (SPC), which has no silica shell, the HA–DTX/PFP@SNC is more stable under various conditions. The MTT assay indicates that the blank HA–PFP@SNC vehicle has no cytotoxicity to A549 cells. Furthermore, due to the HA-mediated tumor-targeting ability, the HA–DTX/PFP@SNC shows obvious cytotoxicity to A549 cells. In vitro and in vivo US imaging results indicate that HA–DTX/PFP@SNC has a stronger and more durable echo signal than DTX/PFP@SPC. Moreover, the in vivo echo signal of HA–DTX/PFP@SNC is stronger than that of DTX/PFP@SNC due to the HA-mediated tumor targeting. Therefore, this novel organic/inorganic hybrid vesicle is a US contrast agent candidate.
研究领域:
医学影像学
·
药剂学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2013
·
IF 4.814
Yibo Hu,Kai Tao,Chunzheng Wu,Chen Zhou,Hongfeng Yin,Shenghu Zhou
Pd@SiO2 core–shell nanoparticles were successfully synthesized by a sol–gel method. Tetradecyl trimethyl ammonium bromide capped Pd nanoparticles were coated with SiO2 through the hydrolysis of tetraethylorthosilicate. The as-synthesized Pd@SiO2 particles consist of Pd cores with a particle size of 3.7 nm and SiO2 shells with a thickness from 10 to 30 nm at different synthetic conditions. The Pd@SiO2 nanocatalysts with 1.9–2.4 nm mesoporous SiO2 shells were generated after removal of tetradecyl trimethyl ammonium bromide from Pd@SiO2 core–shell particles by calcination and following H2 reduction. The relevant characterizations such as XRD, TEM, FT-IR, and BET were carried out for Pd@SiO2 particles, and the results showed that the Pd@SiO2 nanocatalysts were highly stable with the protection of silica shells, and the Pd cores did not increase during thermal treatment and H2 reduction. The studies of catalytic CO oxidation at high temperatures and hydrogenation of nitrobenzene with H2 were tested for Pd@SiO2 nanocatalysts, and the results indicated that Pd@SiO2 nanocatalysts were stable at high temperatures and highly active and stable for hydrogenation of nitrobenzene even after long time use.
研究领域:
材料科学
·
催化化学
✓ 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）