JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 3
·1-6
·
IF 2.02
Chen Shun,Ju Yanyun,Guo Yi,Xiong Chuanxi,Dong Lijie
Ag NPs were in-site synthesized through microemulsion method by reducing silver acetate with oleylamine-mediated at 70 °C with highly monodisperse and narrow size from 10 to 20 nm. The synthesis of Ag NPs was aided by oleylamine and the role of oleylamine was researched. This in-site synthesis approach to Ag NPs was reproducibility and high yield more than 80% with stable store about 6 months.
研究领域:
纳米材料
·
化学合成
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Wei Si,Qingqing Yang,Yuan Zong,Guobin Ren,Ling Zhao,Minghuang Hong,Zhong Xin
During the fabrication of poly(lactide-co-glycolic acid) (PLGA) microspheres by the water/oil/water (W1/O/W2) emulsion solvent evaporation method, water permeation coupled with dichloromethane (DCM) volatilization represents a critical process affecting the microsphere morphology. In this work, the mechanism of pore formation in PLGA through water permeation has been verified. By molecular simulations, the diffusion coefficients of water with different DCM contents were determined. The results showed that the diffusion coefficient decreased rapidly from 53.33 × 10–6 to 6.73 × 10–6 cm2/s after decreasing the DCM mass fraction from 94 to 63%. Furthermore, the higher stirring speed and lower volume of the external aqueous phase promoted the DCM volatilization. Two different mass transfer stages were identified for water permeation, and the first stage could be considered the main mass transfer window because of its high diffusion coefficient. The morphology of PLGA microspheres confirmed the existence of a relationship between water permeation and DCM volatilization.
研究领域:
材料科学
·
制药工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Rui Ding,Wenji Zheng,Kai Yang,Yan Dai,Xuehua Ruan,Xiaoming Yan,Gaohong He
High permeability and selectivity are desirable for mixed matrix membranes (MMMs) based CO 2 separation. Herein, a microemulsion based mixed linker strategy is proposed to introduce amino groups during the growth of ZIF-8. Compared to post-synthetic modification, this method presents a less reduction in S BET of ZIF-8, which is beneficial for CO 2 adsorption. By controlling the ratio of 2-methylimidazole to 2-aminobenzimidazole, NH 2 -ZIF-8 with various morphologies and sizes were synthesized and serve as the filler to fabricate the MMMs for CO 2 capture. From the scanning electron microscopy (SEM), no obvious agglomerations or defects are observed in ZIF-8/Pebax MMMs, due to the amino groups in ZIF-8 can interact with the amide in Pebax chain, which can improve compatibility between ZIF-8 and Pebax. With the amino groups, NH 2 -ZIF-8 shows higher affinity with CO 2 than that of non-amine-functionalized ZIF-8, leading to an enhancement in the separation performances. When the MMM doped with 6 wt% of NH 2 -ZIF-8(10), the CO 2 permeability reaches up to 163.8 Barrer, which increases by around 53% and 107.6% in contrast with the ZIF-8/Pebax MMM and pure Pebax membrane. Besides, the CO 2 /N 2 selectivity is enhanced by around 10% and 27%, respectively. These results indicate that amine-functional modification by mixed ligands is a useful way to construct MOFs-based MMMs with high performance for CO 2 /N 2 separation.
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
MOLECULES
·
2021
·Vol. 26
·期 24
·7449
·
IF 4.412
Xiali Zheng,Wei Luo,Yun Yu,Zebin Xue,Yifan Zheng,Zongjian Liu
A comparative study of the metal emulsion-based synthesis of Sn-based materials in two different types of molten salts (namely LiCl–KCl–CsCl and LiNO3-NaNO3-KNO3eutectics) is presented, and the properties of Sn, Sn-Cu and Sn-Cu-Zn microsphere phase change materials prepared in chloride salts are evaluated by differential scanning calorimetry (DSC) to understand the effect of element doping. Despite a high ultrasonic power (e.g., 600 W or above) being required for dispersing liquid Sn in the chloride system, well-shaped Sn microspheres with a relatively narrow size range, e.g., about 1 to 15 µm or several micrometers to around 30 µm, can be prepared by adjusting the ultrasonic power (840–1080 W), sonication time (5–10 min) and the volume ratio of salts to metal (25:1–200:1). Such a method can be extended to the synthesis of Sn-based alloy microspheres, e.g., Sn-Cu and Sn-Cu-Zn microspheres. In the nitrate system, however, a very low ultrasonic power (e.g., 12 W) can be used to disperse liquid Sn, and the particles obtained are much smaller. At low ultrasonic power (e.g., 12 W), the particle size is generally less than 10 or 4 µm when the sonication time reaches 2 or 5 min, and at high ultrasonic power, it is typically in the range of hundreds of nanometers to 2 µm, regardless of the change in ultrasonic power (480–1080 W), irradiation time (5–10 min), or volume ratio of salts to metal (25:1–1000:1). In addition, the appearance of a SnO phase in the products prepared under different conditions hints at the occurrence of a reaction between Sn droplets and O2in situ generated by the ultrasound-induced decomposition of nitrates, and such an interfacial reaction is believed to be responsible for these differences observed in two different molten salt systems. A DSC study of Sn, Sn-Cu, and Sn-Cu-Zn microspheres encapsulated in SiO2reveals that Cu (0.3–0.9 wt.%) or Cu-Zn (0.9 wt.% Cu and 0.6% Zn) doping can raise the onset freezing temperature and thus suppress the undercooling of Sn, but a broad freezing peak observed in these doped microspheres, along with a still much higher undercooling compared to those of reported Sn-Cu or Sn-Cu-Zn solders, suggests the existence of a size effect, and that a low temperature is still needed for totally releasing latent heat. Since the chloride salts can be recycled by means of the evaporation of water and are stable at high temperature, our results indicate that the LiCl–KCl–CsCl salt-based metal emulsion method might also serve as an environmentally friendly method for the synthesis of other metals and their alloy microspheres.Keywords:molten salts;metal emulsion;microspheres;interfacial reaction;ultrasound
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
PubMed
高影响因子
Materials
·
2017
·Vol. 10
·期 4
·435
·
IF 2.654
Qifeng Chen,Hui Wang,Luyi Sun
Silica aerogel microspheres based on alkali silica sol were synthesized using the emulsion method. The experimental results revealed that the silica aerogel microspheres (4–20 µm in diameter) were mesoporous solids with an average pore diameter ranging from 6 to 35 nm. The tapping densities and specific surface areas of the aerogel microspheres are in the range of 0.112–0.287 g/cm3and 207.5–660.6 m2/g, respectively. The diameter of the silica aerogel microspheres could be tailored by varying the processing conditions including agitation rate, water/oil ratio, mass ratio of Span 80: Tween 80, and emulsifier concentration. The effects of these parameters on the morphology and textural properties of the synthesized silica aerogel microspheres were systematically investigated. Such silica aerogel microspheres can be used to prepare large-scale silica aerogels at an ambient pressure for applications in separation and high efficiency catalysis, which requires features of high porosity and easy fill and recovery.Keywords:silica aerogel microspheres;emulsion method
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·817
·
IF 3.9
Haoyu Yuan,Chao Zhang,Wenjing Chen,Yuzhou Xia,Lu Chen,Renkun Huang,Ruiru Si,Ruowen Liang
Metal–organic frameworks (MOFs) are new porous materials composed of metal centers and organic ligand bridges, which received great attention in the field of photocatalysis. In this work, Ag2CrO4@MIL–125(Ti)–NH2(denoted as AgCr@M125) Z–scheme heterojunctions were synthesized via a simple microemulsion method, by which highly dispersed nano–sized Ag2CrO4can be anchored uniformly on the surfaces of porous MIL–125(Ti)–NH2(denoted as M125). Compared with pure M125 and Ag2CrO4, the as–prepared AgCr@M125 hybrids show significant photocatalytic efficiency against inactivatedStaphylococcus aureus(S. aureus), reaching over 97% inactivation of the bacteria after 15 min of visible light irradiation. Notably, the photocatalytic activity of the obtained 20%AgCr@M125 is about 1.75 times higher than that of AgCr–M125, which was prepared via a traditional precipitation method. The enhanced photocatalytic antibacterial activity of the AgCr@M125 photocatalytic system is strongly ascribed to a direct Z–scheme mechanism, which can be carefully discussed based on energy band positions and time–dependent electron spin response (ESR) experiments. Our work highlights a simple way to enhance the antibacterial effect by coupling with Ag2CrO4and M125 via a microemulsion–assisted strategy and affords an ideal example for developing MOFs–based Z–scheme photocatalysts with excellent photoactivity.Keywords:MIL–125(Ti)–NH2;Ag2CrO4;S. aureus;Z–scheme;microemulsion method
研究领域:
材料科学
·
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xinqiang Cao,Yan Gu,Hailin Tian,Yanfen Fang,David Johnson,Zhiyong Ren,Chuncheng Chen,Yingping Huang
In this work, BiVO 4 composites, containing the tetragonal zircon phase ( tz -BiVO 4 ), and monoclinic scheelite phase ( ms -BiVO 4 ), were synthesized using the microemulsion method. The effect of pH on phase composition and photocatalytic activity were investigated. Based on X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), a ms/tz -BiVO 4 composite forms at pH = 1.0 and pure ms -BiVO 4 is obtained in the pH range 4.0–10.0. The three primary steps in preparing BiVO 4 were monitored by optical microscopy and the role played by the microemulsion on the phase composition of BiVO 4 is explained. Photoluminescence spectroscopy (PL), UV–visible diffuse reflectance spectroscopy (UV-DRS), Brunauer-Emmett-Teller (BET), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were employed to characterize the physical and chemical properties of BiVO 4 composites. The composite formed at pH = 1 exhibited the lowest hole-electron ( h + - e - ) recombination rate, resulting in the highest photocatalytic activity towards microcystin-LR (MC-LR), with near 100% removal of MC-LR in 5 h. ESR and trapping experiments indicated that MC-LR degradation was mediated primarily by hydroxyl radicals (•OH), superoxide radicals (O 2 •− ) and photogenerated holes ( h + ).
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2012
·Vol. 2
·期 12
·5403-5410
·
IF 0
Qinghua Liang,Yao Shi,Wangjing Ma,Zhi Li,Xinmin Yang
Uniform square-like BaFBr:Eu2+ microplates were successfully fabricated via a simple water/oil emulsion method. Various characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Scanning electron microscopy (SEM) and Transition electron microscopy (TEM) were employed to examine the phase, size, morphology, and structure of the products. It was found that the morphology and size of products were strongly dependent on the reaction parameters, such as the ratio of reactants, the reaction time and the reaction temperature. The length and thickness of these square-like BaFBr:Eu2+ microplates can be tuned by adjusting the reaction time and temperature. Well-dispersed cuboctahedron and corner cut cuboid-like BaFBr:Eu2+ particles were produced when the reaction temperature was increased above 60 °C. A possible formation mechanism of the products was discussed based on the time and temperature-dependent experimental results. The optical properties were characterized by photoluminescence (PL) spectroscopy as well as kinetic decay. Eu2+-doped dependent luminescent intensity was investigated in detail. The prepared BaFBr:Eu2+ phosphors are considered promising materials for fluorescent applications.
研究领域:
材料科学
·
无机化学
·
纳米技术
·
光学材料
·
功能材料
✓ 已验证
DOI
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 32
·期 2
·2106828
·
IF 18.808
Yuanyuan Yang,Zhenhao Qiu,Guoying Weng,Huibin Wang,Yanshuo Li,Benhan Fan,Xiu Bai,Qiaohong Zhang,Chen Chen
Amphiphilic silica is synthesized with the simultaneous introduction of two kinds of polar and weakly polar organic groups on its surface using a one-step reverse-phase microemulsion method. The obtained materials present as nanospheres with a size of ≈100 nm. A high percentage (≈80%) of silicon species can be exposed and the amount of surface Si OH increased by above 50% with the introduction of organic groups. Plenty of groups, including polar groups (3-aminopropyl and hydroxyl) and weakly polar group (n-propyl) coexisting on the surface, enable the material to show amphiphilicity. This amphiphilic material can show an excellent property for the removal of various organic dyes from the aqueous solution, and the maximum adsorption capacity of Congo Red, Acid Blue 25, Reactive Blue 19, and Reactive Black 5 can reach 2453.1, 1157.7, 964.6, and 916.9 mg g −1 , respectively. Good reusability is also realized for the present amphiphilic material, which can be reused for at least three times. The reported work provides a successful example to prove that the surface hydrophilicity and lipophilicity can be simultaneously improved just through a simple introduction of certain organic groups, and then realize efficient removal of dyes from the polluted water.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
Yuan Wang,Haibo Rong,Benzhen Li,Lidan Xing,Xiaoping Li,Weishan Li
Ultrafine Li 4 Ti 5 O 12 /C composite is synthesized by microemulsion with oleic acid as carbon precursor and particle size controller. The as-prepared sample is characterized with X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), thermogravimetry analysis (TGA) and nitrogen absorption–desorption isotherms, and its performance as anode of lithium ion battery is determined with charge–discharge test and electrochemical impedance spectroscopy (EIS). The characterizations show that the as-prepared sample is composed of ultrafine Li 4 Ti 5 O 12 particles with average size of 25 nm, which are uniformly dispersed in carbon matrix with a carbon content as low as 2.69 wt%. Charge–discharge test indicates that the as-prepared sample exhibits excellent rate performance and cycling stability. At 10C, the highest discharge capacity reaches 136.3 mAh g −1 and the capacity retention is 96.4% after 100 cycles. The improved performance of the Li 4 Ti 5 O 12 /C composite is attributed to the ultrafine particle size and the uniform composite of Li 4 Ti 5 O 12 with carbon.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2020
·Vol. 12
·期 8
·5075-5083
·
IF 6.895
Yu Dai,Dongpeng Yang,Danping Yu,Songhai Xie,Biwei Wang,Juan Bu,Bin Shen,Wei Feng,Fuyou Li
Fabricating lanthanide doped up-conversion luminescence based nanocomposites has drawn increasing attention in nanoscience and nanotechnology. Although challenging in precise synthesis, structure manipulation and interfacial engineering, fabricating dendritic mesoporous silica coated up-conversion nanoparticles (UCNP@dMSNs) with a tunable pore size is of great importance for the functionalization and application of UCNPs. Herein, we report a strategy to prepare uniform monodisperse UCNP@dMSNs with a core–shell structure. The silica shell has tunable center-radial and dendritic mesoporous channels. The synthesis was carried out in the heterogeneous oil–water microemulsion phase of the Winsor III system reaction system, which allows silica to be deposited directly on hydrophobic UCNPs through the self-anchoring of micelle complexes on the oleic acid ligand. The average pore size of UCNP@dMSNs could be tailored from ∼10 to ∼35 nm according to the varied amounts of co-solvent in the mixture. The microemulsion approach could also be used to prepare hierarchical UCNP@dMSNs with a multi-generational mesostructure. The resultant UCNP@dMSNs exhibit the unique advantage of loading “guest” nanoparticles in a self-absorption manner. We proved that Cu1.8S NPs (∼10 nm), Au NPs (∼10 nm) and Fe3O4 NPs (∼25 nm) could be incorporated in UCNP@dMSNs, which in turn validates the high adsorption capacity of UCNP@dMSNs.
研究领域:
纳米科学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 21
·15196-15203
·
IF 2.993
Song Li,Dong Yan,Shao Qiyue,Jiang Jianqing
Nano-yttrium aluminum garnet (YAG) is a promising material for use in white light-emitting diodes and biological fluorescent probe. However, its existing preparation methods often suffer from low synthesis temperature and particle agglomeration. Therefore, preparing YAG nanoparticles with both high crystallinity and high dispersibility is difficult, which severely limits the applications of nano-YAG phosphor. This work presents a salt microemulsion method that can yield YAG nanoparticles of size 4–6 nm that are dispersed at a high temperature (1000 °C). Transmission electron microscope analysis shows that the precursor particles are dispersed and isolated by nano-sized potassium sulfate particles. Because the melting point of potassium sulfate is high (1067 °C), the precursors and the YAG nanoparticles are always dispersed and isolated by the solid potassium sulfate salt during calcination at high temperatures, resulting in the formation of dispersed YAG nanoparticles with good crystallinity. The reflection spectrum of nano-YAG exhibited a redshift compared to that of bulk YAG. When the Ce content is 0.06, the nano-YAG phosphor exhibited the highest internal photoluminescence quantum yield of 51.2%, and the decrease in the particle size did not increase the quenching concentration. The nano-YAG prepared at a high temperature also exhibited improved optical stability: The luminescence intensity of the nano-YAG decreased by only~ 16% after 48 h of irradiation using blue laser. The obtained 4–6-nm-sized Y 3 Al 5 O 12 :Ce nanophosphors are expected to be ideal materials for novel fluorescent probes and preparation of transparent ceramics.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）