JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2017
·Vol. 84
·期 2
·290-296
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IF 1.575
Li Jie,Zhang Jia,Chen Lianxi,Wang Pengpeng,Wang Yu
Abstract In this study, highly monodisperse cyanoethyl-/cyanopropyl-functionalized silica micro/nanospheres (CN-E-SiO 2 /CN-P-SiO 2 ) have first been synthesized via one-pot sol–gel reaction at room temperature in the microemulsion system. Effects of the surfactant concentrations and the reaction time on the formation of CN-E-SiO 2 /CN-P-SiO 2 have been discussed. Furthermore, bifunctional core–shell structures prepared using CN-E-SiO 2 and CN-P-SiO 2 as core and ureidopropyl-functionalized silica spheres (UD-SiO 2 ) as shell, denoted as CN-E-SiO 2 @UD-SiO 2 and CN-P-SiO 2 @UD-SiO 2 , have also been etched separately in alkaline conditions. Compared with the original CN-E-SiO 2 and CN-P-SiO 2 , transmission electron microscopy images showed that the diameter of CN-E-SiO 2 @UD-SiO 2 and CN-P-SiO 2 @UD-SiO 2 core–shell structures was all reduced during etching in alkaline condition, finally resulting in a hollow structure with a similar sphere size. In addition, for the sake of comparison, pure silica as core and UD-SiO 2 as shell, denoted as SiO 2 @UD-SiO 2 core–shell structure, has also been prepared. However, transmission electron microscopy image indicated that the size and shape of SiO 2 @UD-SiO 2 was almost unchanged in the whole etching process. It can be proved that selective etching of bifunctional core–shell organosilica is an optimal strategy for preparation of hollow materials. Graphical Abstract
研究领域:
材料科学
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纳米技术
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产品关联
DOI
高影响因子
ANALYTICAL LETTERS
·
2012
·
IF 1.016
Kai Wu,Yunyou Zhou,Tao Li,Junyong Sun,Xiaoqing Xing,Qian Song
This paper reports a new optical probe for detect dalapon. We have synthesized the luminescent and stable CdTe quantum dots(QDs) capped with calix[6]arene(C[6]/SiO2/CdTe) via the sol-gel technique in aqueous media. These hybrid organic-inorganic compounds are characterized by IR spectroscopy, ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), and fluorescence. We found that the C[6]/SiO2/CdTe were more stable and had higher fluorescence than the SiO2/CdTe nanoparticles (NPs). The C[6]/SiO2/CdTe show selectivity and sensitivity to dalapon via significant fluorescence intensity decrease. It can be ascribed to the Stern-Volmer equation. Under the optimal conditions, the relative fluorescent intensity was decreased linearly with increasing dalapon concentration in the range of 1.0–25.0 nmol/L with a detection limit of 0.262 nmol/L of dalapon. The possible underlying mechanism is discussed by Langmuir binding isotherm.
研究领域:
分析化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2017
·
IF 2.084
Qian Wang,Xiao Qi Jin,Ji Hong Sun,Shi Yang Bai,Xia Wu
The polymer/SiO 2 hybrid material (P/SiO 2 -MPS) with core-shell structure were synthesized using the dense nanosilica spheres (DNSS) as core and pH responsive poly(acrylic acid) (PAA) as a shell. Meanwhile, using ibuprofen (IBU) as a model drug, the structure and properties of obtained P/SiO 2 -MPS were characterized by SEM, TEM , FT-IR, TGA , EDS, NMR, XRD , DLS and SAXS . The results elucidated that PAA was successfully incorporated onto the surface of DNSS, and thereafter the thickness of PAA shell could be controlled by adjusting the additive amount of AA. Particularly, SAXS patterns evidently exhibited that P/SiO 2 -MPS before IBU-loading and after releasing possessed the surface fractal feature, which increased from 2.19 for SiO 2 -MPS, to 2.41 for P/SiO 2 -MPS, to 2.54 for IBU-loaded P/SiO 2 -MPS, and to 2.65 for IBU-released P/SiO 2 -MPS. Moreover, the IBU-releasing percentage of three samples (P/SiO 2 -MPS-1, P/SiO 2 -MPS-3 and P/SiO 2 -MPS-5) increased gradually at both pH 3.0 and 7.4 with the enlarged thickness of PAA shells, while for P/SiO 2 -MPS-7 with the thickest PAA layer, its release rate was not more than that of P/SiO 2 -MPS-5. Therefore, IBU molecules were hindered from passing through PAA layer. Furthermore, the IBU loading of P/SiO 2 -MPS was fitted into the pseudo-second-order model, while its drug-release kinetic profile was favorable to Korsmeyer-Peppas model. These observations evidently demonstrated that the surface effects of P/SiO 2 -MPS on its surface fractal feature and the diffusion of IBU delivery were very important, and therefore its mechanism was essentially proposed.
研究领域:
材料科学
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药物递送
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生物医学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Jin-Tao Du,Hao Niu,Hao Wu,Xiao-Fei Zeng,Jie-Xin Wang,Jian-Feng Chen
Ammonia borane (AB) is considered to be a promising solid hydrogen carrier. In this work, poly(N-vinyl-2-pyrrolidone) (PVP)-protected platinum nanoparticles are supported on γ-methacryloxypropyltrimethoxysilane (γ-MPS) modified silica spheres (Pt-PVP/SiO 2 (M)), which are firstly used as highly efficient catalysts for hydrolysis of AB. Platinum nanoparticles possess a tiny size of 2–3 nm and are uniformly dispersed over modified silica spheres. Pt-PVP/SiO 2 (M) catalysts with a Pt loading amount of 1.30 wt% show the highest catalytic activity with a turnover frequency (TOF) value of 371 mol H2 mol Pt −1 min −1 (866 mol H2 mol Pt −1 min −1 corrected for the surface atoms) at 25 °C. The activation energy is calculated to be 46.2 kJ/mol. Furthermore, owing to the synergistic effect between the modifier of silica spheres and the capping agent of metal nanoparticles , Pt-PVP/SiO 2 (M) catalysts have a higher loading amount (8.7 and 6.5 times) and TOF value (4.8 and 5.5 times) than the counterparts prepared without γ-MPS and PVP, respectively.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Benjun Huo,Jie Yang,Yao Bian,Daofu Wu,Julin Feng,Jiaer Zhou,Qiang Huang,Fan Dong,Xiaosheng Tang
The superior optical properties and adjustable bandgap allows for hybrid halide perovskite quantum dots to be promising photocatalytic materials, but the serious radiative recombination and instability inhibit the improvement of photocatalytic conversion efficiency. Herein, we successfully synthesized the FAPbBr 3 /A-SiO 2 nanocomposites photocatalyst by anchoring formamidinium (FA + , HC(NH 2 ) 2+ ) lead halide perovskite quantum dots on aminated silica spheres to construct the composite photocatalysts via N H chemical bonding. The FAPbBr 3 /A-SiO 2 composites show the significantly enhanced visible-light-driven NO removal activity (70%) compared to the pristine FAPbBr 3 (30%) in half an hour at room temperature, revealing that the increased active sites and efficient charge carrier separation contribute to the absorption and activation of reactant molecules. This work would open the new possibilities for improving the photocatalytic ability of perovskite quantum dots.
研究领域:
材料科学
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环境科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
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IF 4.182
Hao-Miao Wang,Yan Chen,Xi Yan,Wan-Zhong Lang,Ya-Jun Guo
CrO X- doped mesoporous silica spheres (Cr/MSS-X) were prepared by adding Cr precursors at different preparation stages using sol-gel method (X = 1, 2, 3) and incipient-wetness impregnation method (X = 4), and their catalytic performances of propane oxidative dehydrogenation were evaluated in the presence of CO 2 . The results indicate that for the Cr/MSS-X catalysts prepared by sol-gel method, Cr adding time significantly influences the Cr dispersion, surface physic-chemical properties and their catalytic performance. Cr/MSS-2 catalysts obtained by adding Cr precursor after the tetraethyl-orthosilicate (TEOS) show the optimal catalytic activity. Although Cr/MSS-1 also shows good CrO X dispersion, part CrO X wrapped in the center of mesoporous silica spheres presents weaker catalytic activity. In this work, the catalyst preparation method is quite facile and has the potential to be utilized for industrial production.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2018
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IF 3.789
Tianyi Han,Chenhui Zhang,Jianbin Luo
Superlubricity based on hydration lubrication provides a near-frictionless lubrication state for the extreme reduction of friction in aqueous conditions. Nevertheless, how to obtain the hydration superlubricity under macroscale conditions with higher load-carrying capacity still remains a challenge and the mechanisms governing macroscale superlubricity with hydrated ions are still not well comprehended. Here, we demonstrate that macroscale superlubricity based on hydrated alkali metal ions (Li+, Na+, K+) can be realized under high contact pressure between the Si3N4 ball and sapphire disk. The ultralow friction coefficients of 0.005 are obtained under average contact pressure up to 0.25 GPa by a universal micro-tribometer after a running-in period with acid solutions. The results reveal that running-in stage with acid solutions can not only make the worn region smoother but also generate a silica layer that is easy to shear, which provides excellent boundary lubrication. The hydration superlubricity occurs because hydration shells surrounding the alkali metal ions could generate the hydration repulsive force to sustain a large normal load and have a fluid response to shear simultaneously. These findings pave the way to the scale-up of hydration superlubricity and thus to the wide application of new water-based lubricants.
研究领域:
材料科学
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摩擦学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 49
·期 14
·4919-4926
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IF 2.305
Du Zhiping,Li Enze,Li Guojin,Cheng Fangqin,Wang Guoyong
Yolk–shell silica spheres consisting of a core and an outer shell were prepared by a one-step method using a new class of eco-friendly templates, trisiloxane-tailed surface active ionic liquids. The effects of pH, calcination, and template concentration were investigated in detail. Our results showed that yolk–shell silica spheres could be obtained only in alkaline conditions when using trisiloxane-tailed ionic liquids as templates. The particle diameter, core diameter, dimension of void space, and shell thickness, which we measured by transmission electron microscopy and nitrogen adsorption–desorption techniques, could be tuned by precisely varying the template concentration. The organosilicon component of the ionic liquid template contributes to the reaction during the formation of yolk–shell nanostructures, which leads to a firm silica sphere skeleton resulting in essentially identical morphology and void structure before and after calcination. This investigation provides a convenient approach to fabricate yolk–shell silica spheres, which may expand the application of organosilicon ionic liquids in the field of nanomaterials and could be expected to generate tailor-made yolk–shell silica with functionality in both the core and shell.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2018
·Vol. 24
·期 48
·12600-12606
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IF 5.16
Ang Li,Xue Wang,Tao Wang,Huali Liu,Tunan Gao,Meihong Fan,Qisheng Huo,Zhen-An Qiao
Graphical Filling the gaps : A topotactic synthetic methodology allows the synthesis of nanosized hierarchical MFI zeolite spheres and particles from silica spheres and tetrapropylammonium hydroxide (TPAOH; see figure). Dissolved silica species rebond around TPA + and zeolite structures are generated with defective mesoporous walls as a result of desilication of the initial silica spheres. Upon further crystal growth, zeolite nanoparticles can be obtained. Much effort has been invested in the designed synthesis of zeolites with nanosized and hierarchical structures in recent decades, on account of increasing demands in practical applications, especially catalysis. Herein, a new topotactic synthetic strategy is demonstrated to synthesize nanosized and hierarchical zeolites in a one-step procedure. By using silica spheres as the adjustable amorphous precursors and tetrapropylammonium hydroxide as a structure-directing agent, effortless control of both size and porosity can be achieved in this system with no extra templates. With a simple hydrothermal process, hierarchical zeolite spheres can be modified with acid cites (Al species incorporated in the framework). Benefitting from its mesoporosity, palladium nanoparticles are incorporated into the nanosized hierarchical zeolite, which makes the materials suitable for use in a cascade catalysis reaction of benzimidazole derivatives, including independent acid catalysis and hydrogenation sites. The nanocomposites show exceptional activity and stability in catalysis and recycling reaction. This strategy can be developed into other versatile and practicable scaffolds for advanced zeolite catalytic nanoreactor systems.
研究领域:
材料科学
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化学工程
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催化技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2012
·
IF 4.805
Huiqing Wu,Beibei Tang,Peiyi Wu
A novel hybrid ultrafiltration membrane was prepared by incorporating hollow mesoporous silica spheres (HMSS) into a polymer matrix of brominated polyphenylene oxide (BPPO) using triethanolamine as the amination agent. The hybrid membrane exhibits improved water permeability, thermal stability, and water content, while the rejection to egg albumin maintaining at a high level (>90%). Especially when the addition of HMSS is 1.0 wt %, the water flux of the hybrid membrane reaches a maximum that is almost two times that of the BPPO membrane. The unique properties of HMSS and good interaction between HMSS and polymer contribute to the improvement of membrane performance. The effect of the structures of silica particles on the membrane performance was also investigated, and the results suggest that HMSS with moderate wall thickness is more suitable for the optimization of hybrid membrane properties.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2020
·
IF 7.094
Dongzhi Tao,Xiang Li,Yubing Dong,Yaofeng Zhu,Yumin Yuan,Qingqing Ni,Yaqin Fu,Shaoyun Fu
Global warming aggravates mainly due to human activities , such as the massive use of fossil energy and excessive deforestation. Thus, reducing energy waste becomes has gained more importance. Thermal insulation materials with superlow thermal conductivity show notable potential in energy saving. Herein, an adiabatic hollow silica/polyacrylonitrile (SiO 2 -PAN) fibrous nanocomposite membrane was prepared via electrospinning. Hollow SiO 2 spheres were prepared by using tetraethyl orthosilicate as a silica source and hydrothermal carbon spheres as the template. The thermal insulation property of PAN fibrous nanocomposite membrane can be enhanced by appending hollow SiO 2 spheres. The solid conduction of the fibrous nanocomposite membrane was reduced by the addition of hollow SiO 2 spheres. The composite fibrous nanocomposite membrane is flexible and achieves an optimal thermal conductivity of 16 mW/(m·K). The fibrous nanocomposite membrane can maintain its thermal insulation property and becomes hydrophobic after treatment with silicone oil . The developed membrane provides a new idea for the future development of thermal insulation materials.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 33
·13997-14004
·
IF 3.288
Yangyi Sun,Yijing Mao,Ningyu Di,Xiaolong Chen,Dongming Qi,Baoqing Shentu
Herein, using an acid-hydrolyzed tetraethyl orthosilicate (TEOS)/bis(triethoxysilyl)ethane (BTEE) mixture as a precursor for the traditional surfactant-assembly synthesis of mesostructured silica spheres instead of directly purchased commercial precursors, molecularly ethane-bridged hollow mesoporous silica spheres (MEB-HMSs) with radial mesochannels and an enlarged pore size were successfully synthesized without any additional core templates. The composition, pore size, particle size, shell thickness, and rate could be controllably tailored by only changing the amount of reagents used in the reaction. The cytotoxicity assay confirmed that MEB-HMSs have good biocompatibility, together with good Dox-loading capacity.
研究领域:
材料科学
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生物医学工程
✓ 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）