JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
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2017
·Vol. 17
·期 6
·3744-3750
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IF 1.483
Yang Guangming,Yu Hongbo,Zhang Jianfeng,Yin Hongfeng,Ma Zhen,Zhou Shenghu
AuPd nanoparticles (NPs) protected by tetradecyl trimethyl ammonium bromide (TTAB) were coated with SiO2 through hydrolysis of tetraethylorthosilicate (TEOS). The as-synthesized AuPd@SiO2 core–shell NPs were calcined in air at 500 °C to remove TTAB and
open up mesopores within the SiO2 shells. The obtained Au–PdO@m-SiO2 NPs were reduced by H2 at 300 °C to obtain AuPd@m-SiO2 NPs with AuPd NP cores (diameter: ~3 nm) and SiO2 shells (thickness: ~18 nm). Results from relevant characterization
indicated that these SiO2-protected core–shell NPs were highly stable during calcination and subsequent reduction. Au@m-SiO2, Au10Pd@m-SiO2, Au5Pd@m-SiO2, AuPd5@m-SiO2, AuPd10@m-SiO2,
and Pd@m-SiO2 NPs with similar core sizes and shell thicknesses were also synthesized. These samples were tested in the catalytic hydrogenation of p-chloronitrobenzene. The activity and selectivity were found to be tunable, depending on the composition of the bimetallic alloys.
AuPd@m-SiO2 NPs with a 1/1 molar ratio of Au/Pd showed the highest selectivity for the hydrodechlorination of p-chloronitrobenzene.
研究领域:
材料科学
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催化
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化学工程
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纳米技术
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 20
·9472-9483
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IF 2.302
Wang Qiang,Feng Jin,Ma Lirong,Wei Wei,Xie Jimin,Xia Changkun,Zhu Jianjun,Jiang Deli
Monolithic silica aerogels were prepared by sol–gel process via ambient drying process. TEOS and APTES were used as coprecursors and wet gels were crosslinked by three kinds of diisocyanate. The strengthened silica aerogels possess densities which range from 0.298 to 0.463 g/cm 3 , and the specific surface areas range from 81.17 to 135.48 m 2 /g. In this paper, silica aerogels crosslinked with different diisocyanate were used as adsorbents for the removal of heavy metals. At the same time, some factors such as the initial pH and concentration of heavy metals were investigated by a batch of experiments. The equilibrium sorption data have been fitted by different isotherm model, and the data fitting by Freundlich isotherm model indicates that the process of adsorption is favorable. Under the condition of the optimum adsorption pH, the maximum theoretical adsorption capacity computed from Langmuir model is 118.73 mg/g for Pb 2+ , 57.03 mg/g for Cr 3+ , and 60.86 mg/g for Cd 2+ , respectively with the silica aerogels crosslinked with 1,6-hexamethylene diisocyanate (HDI).
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2018
·
IF 5.091
Dongmei Lin,Xingrong Zeng,Hongqiang Li,Xuejun Lai,Tongyi Wu
Waterproof and flame-retardant fabrics are widely utilized in many fields, such as automotive interiors, indoor decorations, outdoor clothing and tents. Herein, a facile one-pot sol-gel approach was developed to construct superhydrophobic and flame-retardant (SFR) coatings on cotton fabrics. The cotton fabric was activated by O 2 plasma and then immersed into the ethanol suspension containing tetraethoxysilane (TEOS), hydroxyl-terminated polydimethylsiloxane (HPDMS) and ammonium polyphosphate (APP). The hydrogen bonding interaction between APP and cellulose motivated the APP to attach to the cotton fibers during the initial stirring process. After the addition of ammonia, the in situ sol-gel reaction of TEOS and HPDMS was initiated to generate polydimethylsiloxane-silica hybrid (PDMS-silica). The micro-nano structured composite coating on cotton fabric was successfully fabricated by the PDMS-silica and APP. The SFR cotton fabric showed outstanding durability and self-cleaning ability with a water contact angle (WCA) above 160°. When exposed to fire, the SFR cotton fabric quickly charred to extinguish the fire by generating a dense intumescent char layer under the physical barrier effect of PDMS-silica and the intumescent flame-retardant effect of APP. This one-pot approach for fabricating SFR cotton fabric is simple, cost-effective and timesaving, demonstrating significant advantages in practical production.
研究领域:
材料科学
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纺织工程
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化学工程
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产品关联
DOI
PubMed
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2021
·
IF 7.491
Youwen Tian,Wei Luo,Yedan Wang,Yun Yu,Wanzhen Huang,Haodong Tang,Yifan Zheng,Zongjian Liu
Although the traditional Stoˇber process-based methods are widely used for encapsulation of metal nanoparticles in SiO 2 , these time-consuming methods are not effective for coating metal microparticles with a uniform SiO 2 layer of desired thickness. Herein, an ultrasound-assisted, interface-confined sol–gel method is proposed for fast encapsulation of metal microparticles in SiO 2 , and the encapsulation of Sn microparticles is chosen as an example to illustrate its feasibility. The proposed method involves covering metal microparticles with liquid films that contain water, alcohol, surfactant (Span-80) and catalyst (NH 4 F) and then ultrasonically dispersing these particles into cyclohexane, where tetraethylorthosilicate (TEOS) is added. To ensure the hydrolysis-condensation reactions of TEOS occurring at the particle-cyclohexane interface so that the formed SiO 2 is coated on the particles, the microparticles should be well dispersed into cyclohexane with the liquid films being not broken away from their surfaces. It is found that the assistance of probe sonication and the addition of surfactant are crucial to achievement of a good dispersion of metal microparticles in cyclohexane. And using high-viscosity alcohol (namely glycerol), controlling the volume ratio of water to alcohol and the amount of water, and choosing a suitable ultrasonic power are essential for preventing the formation of free SiO 2 (namely SiO 2 that is not coated on the particles), which is a result that the liquid films escape from the particle surfaces under ultrasonic cavitation. Our results have also revealed that the thickness of SiO 2 layer can be adjusted by changing the reaction time or the total amount of water. In particular, the thickness of SiO 2 layer can be easily raised by simply repeating the encapsulation procedure. Compared with the traditional Stoˇber process-based methods, the proposed method is time-saving (reaction time: about 30 min vs. more than 12 h) and extremely effective for coating microparticles with a continuous, uniform SiO 2 layer of desired thickness.
研究领域:
材料科学
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化学工程
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纳米技术
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DOI
PubMed
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 17
·10006-10016
·
IF 3.119
Ruimin Li,Shiyong Xing,Shuai Zhang,Minghan Han
H-beta zeolites of 100–200 nm (named BEA-L) and 20–30 nm (named BEA-S) were treated by chemical liquid deposition (CLD) of tetraethyl orthosilicate (TEOS) to improve the selectivity of 2-phenyl linear alkylbenzene (2-LAB) from benzene alkylation with 1-dodecene. The results indicate that H-beta zeolite with a smaller crystal size has a longer lifetime due to shorter channels and less diffusion limitation. The deposited SiO2 layers passivated the external surface acid sites of the zeolite and made the pores narrower. BEA-L lost more external Brønsted acid sites than BEA-S with the same added amount of TEOS, which was due to the severe aggregation of BEA-S grains. This increased passivation gave BEA-L increased 2-LAB selectivity. And when the added amount of SiO2 was 7.20 wt% of the parent zeolite, the selectivity of 2-LAB over BEA-L significantly increased from 41.9% to 54.7% while that of BEA-S only increased by 2%.
研究领域:
催化
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化工
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材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 12
·3088-3096
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IF 5.256
Xinmin Cui,Ruimin Ding,Mengchao Wang,Conghui Wang,Jing Zhang,Jing Wang,Wensheng Dong,Yao Xu
An ultralow-index top layer is a prerequisite to preparing high-performance broadband AR coatings. When coupled with hydrophobicity and the abrasion-resistance required in practical applications, the challenge becomes even greater. In this work, a MgF2 AR coating was studied because of the low refractive index of MgF2 and its easily realized strong adhesion through low-temperature heat treatment. In order to obtain an ultralow refractive index and endow the coating with hydrophobicity, we designed several experimental routes and finally adopted MTES/TEOS co-precursors to direct MgF2 particles to form a honeycomb-like network structure without a template. A final refractive index of 1.15 and good hydrophobicity, with a water contact angle of 122°, were obtained using the MgF2–SiO2(CH3) coating. These superior properties were attributed to the incorporation of methyl groups, which not only endowed the coating with hydrophobicity, but also changed the original linear assembly of MgF2 particles to a circular assembly. Using this hydrophobic ultralow-index coating as a top layer, a high-performance double-layer AR coating was fabricated with a high average transmittance of 99.43% in the wavelength range of 400–1000 nm, good abrasion-resistance, and damp heat resistance after a low-temperature heat treatment of 250 °C. This MgF2 double-layer AR coating may be used in display devices or lenses.
研究领域:
材料科学
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光学
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表面工程
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 47
·41323-41330
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IF 3.289
Qiao-Ling Gao,Fei Fang,Chen Chen,Xue-Yan Zhu,Jing Li,Hong-Ying Tang,Zhong-Biao Zhang,Xiao-Jun Huang
A versatile strategy to fabricate newly-developed silica-modified membranes based on organic/inorganic hybridization for oil/water separation is described in this study. The modified membranes are easily obtained by a simple two-step immersion of polysulfone hollow fiber membranes with radial gradient microstructure (RGM-PSF) into a silicon solution of tetraethyl orthosilicate (TEOS) mixed with 3-glycidyloxypropyltrimethoxysilane (GOPTS) and subsequently into a lactic acid solution. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FE-SEM) were utilized to characterize the surface compositions and microstructures. A micro/nano-scaled SiO2-based coating was generated roughly and continuously on the membrane surfaces, endowing them with superhydrophilicity and underwater superoleophobicity. Results of dead-end filtration experiments demonstrated that the hybridized RGM-PSF membranes could be applied in oil-in-water emulsion separation far more efficiently, with higher water permeate flux, better oil rejection ratio, and higher pressure endurance than those of the common ones. Therefore, this study has provided a facile approach to prepare silica-modified membranes with special wettability, showing prominent application prospects for oily wastewater treatment in practical processes.
研究领域:
材料科学
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环境工程
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膜技术
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产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2014
·Vol. 22
·期 1
·219-228
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IF 1.316
Wang Yuebo,Lin Xiaoqin,Wen Ke,Zhu Jianxi,He Hongping
In this study, a series of surfactants with different chain lengths were used to investigate the effect of organic templates on the structural properties of porous clay heterostructures (PCH). The variation tendencies of structural properties and chemical component were characterized by X-ray diffraction, CHN elemental analysis, major element analysis, and nitrogen adsorption/desorption at −196 °C. Non-local density functional theory was employed to characterize pore size distributions in both micropore and mesopore regions owing to the bi-model pore structures of PCH. The major textural parameters of PCH samples increased with increasing the chain length and the intercalated amount of template agent, while the most probable pore size remained unchanged around 1.3–1.4 nm. Based on the structural and chemical component results of PCH, a non-micellar template model was presented to explain the formation mechanism of porous structure. By the extrusion and occupation of polymerizate of TEOS within interlayer, a fixed number of hydrocarbon chains congregate together to form surfactant aggregates (template). The aggregates with different chain lengths cause the increase of pore volume in depth dimension rather than in diameter. The obtained results also shed some light on the different roles of inorganic base clay and organic template agents in the formation of porous structure. Montmorillonite as the inorganic host supplies the space for pillaring reaction and controls the arrangement of template agent within interlayer. As the template agent and modifying agent, the cationic surfactant is the dominant factor in forming pores relative to amine. The neutral amine mainly serves as catalyst for the polymerization of TEOS besides its co-template effect.
研究领域:
材料科学
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化学
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纳米技术
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产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 90
·73424-73433
·
IF 3.84
Yingchun Wang,Ningwei Wang,Xiaoni Ni,Qianqian Jiang,Wenming Yang,Weihong Huang,Wanzhen Xu
In this study, molecularly imprinted technology, combined with fluorescence measurement and computer simulation, was used to detect contaminant p-nitrophenol. Seven molecular dynamics simulations of molecular imprinting prepolymerization systems were performed to optimize the imprinting shell. Results indicated that the system with a p-nitrophenol (4-NP): 3-aminopropyltriethoxysilane (APTES): tetraethylorthosilicate (TEOS) mole ratio of 8 : 8 : 12 led to the best stable template–functional monomer clusters and the hybrid SiO2 layer with CdS-like clusters on the surface of CdTe was synthesized by a simple reflux procedure. The prepared imprinted materials (CdTe@SiO2-MIPs) on the surface of silica contained CdTe nanoparticles (CdTe@SiO2) by surface imprinting and Stöber method polymerization were characterized by transmission electron microscopy, fluorescence spectroscopy, Fourier-transform infrared spectroscopy, ultraviolet–visible analysis and X-ray diffraction. A linear relationship between relative fluorescence intensity and the concentration of 4-NP was obtained with a limit of detection of 0.08 μmol L−1 and the imprinting factor (IF) was 2.23 which indicated that special binding sites with binding property to p-nitrophenol were created on the surface of the CdTe@SiO2-MIPs materials. Ultimately, the feasibility of the fluorescent materials was successfully evaluated through the analysis of 4-NP in tap water and lake water. The recoveries were above 97.3%.
研究领域:
材料科学
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分析化学
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环境科学
·
计算化学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Jiancheng Lan,Hammad Saulat,Haowen Wu,Liangqing Li,Jianhua Yang,Jinming Lu,Yan Zhang
The good quality pure-silica MFI zeolite membrane with hydrophobic surface was fabricated by the addition of TBABr in “TEOS-TPAOH-H 2 O” synthesis solution. The effects of TBABr on PV performance and the microstructure of MFI membranes were explored by pervaporation, single-component gas permeation, water contact angle, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS) and 13 C solid state CP MAS NMR. It was found that small amounts of TBABr could accelerate the growth and contribute to compact membranes with high bulk Si/Al ratio and good hydrophobic surface, hence resulting in better pervaporation performance. Excessive amounts of TBABr would interfere the crystallization and result in lower pervaporation performance. For example, when the TBABr/Si ratio increased to 0.01 from 0 with the TPAOH/Si ratio of 0.09, the membrane separation factor was increased from 35 to 59 with the flux of 1.85 kg m −2 h −1 for 5 wt% of ethanol/water mixtures at 60 °C.
研究领域:
化学工程
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材料科学
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膜技术
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2017
·
IF 2.858
Ghulam Muhyodin,Xiaoqun Zhu,Masroor Abro,Ghulam Yasin,Inamullah Maitlo,Muhammad Yasir Akaram,Jun Nie
Tetraethyl ortho-silicate (TEOS) and octadecyl 2-((3-(triethoxysilyl) propyl) amino) acetate (SP) are used as modification agents at the ratios of 1:5, 1:1, 4:1 and 1:0 of TEOS: SP to form the silica by sol-gel process. Silica in both liquid form as well as powder forms at different compositions by weight percent have been subjected to the photo-polymerization with polyethylene glycol diacrylate (PEGDA) in the presence of photo initiator (2- hydroxyl − 2–methyl – 1- phenyl −1–prop none (1173)). FTIR study is performed to identify various functional groups in the prepared materials, whereas, TEM and SEM are conducted to investigate particle size and surface morphology respectively. Moreover, transition glass temperature, storage and loss modulus are reported via DMA. The results indicated that TEOS: SP ratio has proved to be highly significant, among them 1:5 ratio is the most beneficial in terms of yielding maximum self-floating, hydrophobicity and roughness with minimum glossy nature of silica.
研究领域:
材料科学
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化学工程
·
纳米技术
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产品关联
DOI
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 46
·5919-5928
·
IF 2.378
Nasibeh Saeedzadeh Amiri,Mohammad-Reza Milani-Hosseini
A facile and environmental-friendly strategy was used to prepare ratiometric fluorescence sensor-modified mesoporous-structured epitope-imprinted polymer (QDs@SiO2@EMSiO2) for highly sensitive and selective determination of cytochrome c (Cyt c), using Cu-doped ZnS QDs and Mn-doped ZnS QDs as fluorescent dyes. In this sensor, C-terminal and N-terminal nonapeptides were employed as the template molecules, and C18MIMCl was utilized as a template for mesoporous silica. APTES and PTESMIC were utilized as functional monomers and TEOS was applied as the cross-linker. The as-prepared fluorescence sensor displayed great selectivity and sensitivity by merging ratiometric fluorescence methodology with mesoporous silica materials to create one system. The composite was employed for the recognition of Cyt c, which displayed good linearity in the range from 0.4 nM to 200.0 nM with a detection limit as low as 0.15 nM, which was much lower than those of non-mesoporous and single emission composites. The sensor also exhibited outstanding applicability in complex matrices, which enabled its employment for Cyt c tracing in human serum samples without any pretreatment.
研究领域:
分析化学
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材料科学
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生物传感器
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生物技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）