Progress in Natural Science-Materials International
·
2019
·
IF 3.31
Hongming Zhang,Dandan Ke,Lina Cheng,Xuelei Feng,Xuewei Hou,Jin Wang,Yuan Li,Shumin Han
CoPt-Co hybrids were successfully supported on amino modified SiO 2 nanospheres by a chemical reduction method at a temperature of 278 K. The solid carrier i.e. amino modified SiO 2 , provides numerous anchoring sites for the metal nanoparticles (NPs) to improve the dispersion while reducing the size of metal NPs. The supported NPs displayed a narrow particle size distribution on the SiO 2 surface with an average diameter of 12 nm. The XRD results alongside with the binary alloy phase diagram suggest that the resulted NPs are bimetallic, composed of CoPt and amorphous Co. Among the prepared materials, the solid with the specific composition of SiO 2 @Pt 0.1 Co 0.9 was proved to be effective catalyst for ammonia borane (AB) hydrolysis in aqueous solution. The turnover frequency (TOF) value of the supported nanocatalyst was 25.59 mol H 2 ⋅ min − 1 ⋅ mol M − 1 , almost twice as that of unsupported Pt 0.1 Co 0.9 NPs while the activation energy was 37.05 kJ mol −1 . Furthermore, the SiO 2 @Pt 0.1 Co 0.9 composite manifested high catalytic activity even after five cycles of reuse.
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2016
·
IF 1.207
Liang Wang,Anqi Liu,Zhaohui Zhang,Bin Zhao,Yingming Xia,Yun Tan
In this work, a novel catalyst of Fe 3 O 4 @SiO 2 @Yb 2 O 3 was prepared and the degradation of thymol in reverse osmosis concentrate using ozonation was explored. The operational parameters, such as ozone dosage (8–48 mg·min − 1 ), initial thymol concentration (20–100 mg·L − 1 ), initial pH value (3–11), and catalyst Fe 3 O 4 @SiO 2 @Yb 2 O 3 dosage (0.2–1.0 g), were studied focusing on the thymol degradation and COD removal. The results indicated that the increase in ozone dosage, initial pH value, and Fe 3 O 4 @SiO 2 @Yb 2 O 3 dosage accelerated the thymol degradation and COD removal, while the increase in initial thymol concentration hampered the effect of ozonation. A pathway of thymol degradation by catalytic ozonation was proposed based on the intermediates detected by gas chromatography-mass spectrometer and ion chromatography . This paper can provide basic data and technical alternative for pollutant removal from reverse osmosis concentrate by ozonation.
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高影响因子
RSC Advances
·
2021
·Vol. 11
·期 3
·1668-1678
·
IF 3.361
Dechao Chen,Sai Ma,Xiaofan Zhang,Xuedong Wang,Ming Gao,Jieyi Li,Huili Wang
The reported ionic liquid (IL)-based magnetic effervescent tablets are a result of direct addition of ILs and magnetic nanoparticles (MNPs). In effervescent reaction-enhanced microextraction procedures, the dissociation between ILs and MNPs easily leads to loss of ILs due to aqueous solubility, thereby decreasing the extraction efficiency. Herein, we attached a hydrophilic IL ([BMIM]Br) onto the surface of NiFe2O4@SiO2@polyaniline (NiFe2O4@SiO2@PANI-IL) to prepare novel core–shell-like multi-layer nanocomposites. Magnetic effervescent tablets were composed of Na2CO3 as an alkaline source, tartaric acid as an acidic source and as-synthesized nanocomposites as an extractant. The nanocomposites were used in an effervescent reaction-enhanced magnetic solid-phase extraction (ERMSE) for the extraction of four organophosphorus pesticides (OPPs) in fruit juices prior to HPLC-DAD detection. Under optimized conditions, this method provided low limits of detection (0.06–0.17 μg L−1), high recoveries (80.6–97.3%) and excellent precision (1.1–5.2%) for OPP quantification in five fruit juices. Notably, the three-layer core–shell nanocomposites were efficiently recycled for at least eight extraction cycles with a recovery loss of <10%. The novelty of this study lies in: (1) for the first time, the ILs-based hybrid magnetic nanocomposites were prepared with appropriate pore size/volume and more active sites for OPPs; (2) the combination of the nanocomposites with effervescent tablets realizes rapid dispersion of CO2 bubbles, and convenient magnetic separation/collection into one synchronous step; and (3) due to there being no requirement of electrical power, it is feasible for use in field conditions. Thus, the ERMSE method has excellent potential for conventional monitoring of trace-level OPPs in complex fruit juice matrices.
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高影响因子
CHROMATOGRAPHIA
·
2022
·Vol. 85
·期 9
·851-863
·
IF 2.213
Jiang Xiao-Xue,Sun Yue-Na,Zhang Chen,Yang Zhao,Yu Li-Qing,Lv Yun-Kai
In this paper, SiO 2 @MOF-199 composite with core–shell structure was prepared by in-situ growth of MOF-199 on the surface of SiO 2 microspheres, and SiO 2 @MOF-199 coated fiber was prepared for headspace solid phase microextraction (HS-SPME) of phthalate esters (PAEs) in plastic bottled milk. The prepared SiO 2 @MOF-199 has both mesoporous structure of SiO 2 and microporous structure of MOF-199. The hierarchical porous structure not only gives the analyte higher adsorption performance, but also improves the diffusion rate of the analyte in SiO 2 @MOF-199. The coated fibers have good thermal stability and are relatively uniform in size and structure. The extraction conditions of the prepared fibers for PAEs were optimized by single factor optimization and response surface Box-Behnken design. Under optimized conditions, the fiber displays wide linear ranges of PAEs (dimethyl phthalate, diethyl phthalate and diallyl phthalate are 5–800 ng L −1 , di-n-butyl phthalate, butyl benzyl phthalate and di-n-octyl phthalate are 50–1000 ng L −1 ), low limits of detection (0.3–19.8 ng L −1 ), and high enrichment factors (325–2089). The intra-day and inter-day relative standard deviations (RSD) for PAEs extractions using a single fiber were (4.7–8.5%) and (5.7–9.1%), respectively. The fiber-to-fiber reproducibility for three fibers prepared in parallel was 7.2–11.3% (RSD). The method was successfully applied to the extraction of PAEs from plastic bottled milk and to the quantitation by a gas chromatograph with a flame ionization detector. The average recoveries were 84.0% to 105%.
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高影响因子
TALANTA
·
2019
·
IF 4.916
Muhammad Muhammad,Guohua Yao,Jie Zhong,Kuanglin Chao,Muhammad Hammad Aziz,Qing Huang
Fipronil is a phenylpyrazole insecticide commonly used in agriculture and residential applications. In this paper, we reported a novel label-free surface-enhanced Raman spectroscopy (SERS) method for detection of fipronil residues in chicken eggs (mostly accumulated on the egg membrane). We fabricated the SERS substrates composed of the SiO 2 @Au core/shell nanoparticles and probed the contamination of fipronil residue on the egg membrane. The identification of the characteristic Raman bands of fipronil was achieved with the aid of density functional theory (DFT) calculation, with which we could analyzed the trace amount of fipronil in a quantitative way. As such, this work may provide a practical solution to quick inspection of fipronil contamination in chicken eggs or other foods.
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高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2023
·
IF 4.5
Miao TIAN,Qiong-qiong WANG,Qin-meng WANG,Wei LI,Xue-yi GUO
The effect of MgO on the phase equilibria between matte and tridymite-saturated FeO x −SiO 2 −MgO slag was investigatedusing high-temperature equilibration and microanalysis technique. The results showed that at 1300 °C and p (SO 2 ) of 10 kPa, the presence of MgO reduced the FeO activity of the slag, leading to the decrease in the oxygen partial pressure ( p (O 2 )) over the slag and the Cu solubility in the slag. Due to the lower FeO activity, FeS was oxidized from matte into slag, increasing the Cu concentration of the matte. In high-SiO 2 concentrationslags, excessive MgO in the liquid slag recrystallized as solid olivine (Mg 2 SiO 4 −Fe 2 SiO 4 ), increasing the slag viscosity and copper losses in the slag. The maximum MgO solubility in the FeO x −SiO 2 −MgO slag increased from 3 wt.% to 8 wt.% when the temperature raised from 1200 to 1300 °C under p (O 2 ) of 10 −6 kPa. At higher MgO content, the slag composition could be optimized by increasing temperature and adding SiO 2 flux to maintain a fully molten slag or avoid high proportions of solids.
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高影响因子
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
·
2024
·
IF 3.6
Jianhao Cheng,Chen Shi,Yubing Dong,Jian Han
Ultraviolet (UV) radiation has a detrimental effect on the outdoor lifetime of PVC film materials. TiO2 nanoparticles, as commonly used UV absorbers, still suffer from poor transparency, high photocatalytic effect, and poor dispersion in PVC matrix. To mitigate these effects effectively, titanium dioxide nanorod @ silicon dioxide (TNr@SiO2) was synthesized and used as an anti-UV aging agent for polyvinyl chloride (PVC). The agglomeration effects of TiO2 nanoparticles in PVC films were solved by synthesizing TNr, and the catalytic effects of TiO2 was reduced by growing SiO2 on the TNr surface. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-visible spectroscopy were utilized to demonstrate the excellent dispersion and low photocatalytic effects of the synthesized TNr@SiO2. Compared with pure PVC film, the color change of TNr@SiO2/PVC composite film is not evident after 800h of UV aging, and the retention of mechanical properties were 93.94%. Compared with TiO2/PVC, TNr@SiO2/PVC composite film has better transparency. Results show that TNr@SiO2 can maintain the properties of PVC better because the electrons of TNr@SiO2 are excited to form a positively charged hole after the absorption of UV light, and then the hole electron pairs are recombined and converted into thermal energy, which improves the durability of PVC. Therefore, this highly transparent TNr@SiO2/PVC composite film with low photocatalytic activity and high UV resistance will soon be applied in large-scale industrial production.
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高影响因子
CHEMICAL PHYSICS LETTERS
·
2021
·
IF 2.328
Ziyu Pan,Bin Liu,Bo Wang,Yingchao Liu,Tingyu Si,Wencai Yi,Yangqing Wu,Jinkai Li,Bingqiang Cao
Lead-free double-perovskite Cs 2 SnX 6 (X = Cl, Br, I) containing Sn 4+ is a more stable lead-free photovoltaic material than its homologue CsSnX 3 . However, its stability in air still affects its application. In this Letter, lead-free inorganic Cs 2 SnX 6 (X = Cl, Br, I) nanocrystals (NCs) were synthesized by a hot injection method and in-situ loaded into mesoporous SiO 2 . With the change of halogen content, the PL emission peak of pristine Cs 2 SnX 6 NCs were tuned from 430 nm to 780 nm covering the visible and near infrared spectrum region. Taking Cs 2 SnI 6 /SiO 2 NCs as an example, the optical property stability in solution is obviously improved, and it can be stored in air for over 2 h. Especially, the more stable NIR emission, non-toxicity and easy hydrolysis characteristics of Cs 2 SnX 6 /SiO 2 composite nanoparticles will have potential medical applications like photothermal and photodynamic therapies for cancers.
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Wenwen Guo,Shibin Nie,Ehsan Naderi Kalali,Xin Wang,Wei Wang,Wei Cai,Lei Song,Yuan Hu
The SiO 2 @metal organic framework (Universitetet i Oslo-66, UiO-66) core–shell microspheres were constructed through covalent linkage between amine groups in UiO-66-NH 2 and epoxy groups on the surface of silica . The morphology and size of the SiO 2 @UiO-66 core–shell microspheres could be simply controlled by tuning the ratio between UiO-66-NH 2 and epoxy terminated silica (E-SiO 2 ). As observed by TEM , the SiO 2 @UiO-66 hybrids showed better dispersion state within epoxy matrix compared to either E-SiO 2 or UiO-66-NH 2 . The incorporation of SiO 2 @UiO-66 hybrids slightly promoted the thermal degradation of the resultant epoxy composites but improved residual yield. The dynamic mechanical analysis results indicated that the SiO 2 @UiO-66 hybrids slightly increased the glass transition temperature and the modulus. The SiO 2 @UiO-66 hybrids exhibited higher efficiency in reducing the heat release rate and the smoke production rate compared to either E-SiO 2 or UiO-66-NH 2 . The influence of the component ratio in SiO 2 @UiO-66 on flame retardancy of the epoxy composites was also studied by cone calorimeter . Specifically, the SiO 2 @UiO-66 hybrid with medium ratio (SiO 2 @UiO-66-2) exhibited maximum reduction in peak heat release rate (−31%), total heat release (−23%) and total smoke production (−16%). The char residues were investigated by the Fourier transform infrared spectra, scanning electron microscopy and X-ray photoelectron spectroscopy, which demonstrated that the enhanced flame retardancy of EP/SiO 2 @UiO-66-2 was attributable to the continual morphology and high thermal resistance originated from the presence of the silicon and zirconium complex. These favorable characteristics including high flame retardant efficiency and good smoke suppression make SiO 2 @UiO-66 hybrids promising for flame retardant polymers application .
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2014
·Vol. 293
·期 2
·463-471
·
IF 2.41
Qi Dongming,Liu Chenghai,Chen Zhijie,Dong Guifang,Cao Zhihai
Poly(methyl methacrylate- co -butyl acrylate) (poly(MMA- co -BA))/SiO 2 nanocomposite particles with various morphologies were prepared through in situ emulsion copolymerization of methyl methacrylate and butyl acrylate using surface 3-(methacryloyloxy) propyl trimethoxysilane (MPS)-modified SiO 2 nanoparticles as nanofillers. The surface MPS-coupling density of SiO 2 nanoparticles could influence the hydrophilic–lipophilic properties of SiO 2 nanoparticles and subsequently influence the particle morphology of poly(MMA- co -BA)/SiO 2 nanocomposite particles. With the increase of the surface MPS-coupling density of SiO 2 nanoparticles, the morphology of nanocomposite particles changed from a raspberry-like one to a guava-like one. A formation mechanism of nanocomposite particles with various morphologies was proposed on the basis of the results of polymerization kinetics, particle size evolution in the process of polymerization, and particle size and morphology of the final nanocomposite particles.
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高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Xiaoshan Zhang,Yonggang Jiang,Nana Xu,Haiyan Liu,Nan Wu,Cheng Han,Bing Wang,Yingde Wang
The radome and antenna windows of aerospace aircrafts highly require multifunctional materials that are thermal stable, capable of wave-transparent and have excellent thermal insulation performance. Due to the SiO 2 aerogel with high thermal stability, low dielectric constant and ultralow thermal conductivity , they are considered as promising high-temperature thermal insulating and wave-transparent materials. In this work, the SiBNO fibers with good wave-transparent performance were used as reinforcements to prepare SiO 2 aerogel composites (SiBNO f /SiO 2 ACs) by sol-gel impregnating and supercritical drying method. The prepared SiBNO f /SiO 2 ACs exhibit integrated performances of excellent fire resistance, high-temperature stability (1100 °C in Air), high mechanical properties (compressive strength is 1.89 ± 0.14 MPa at 40 % strain and bending strength is 1.93 ± 0.03 MPa), ultralow thermal conductivity (0.029 W m −1 K −1 at 25 °C and 0.051 W m −1 K −1 at 1100 °C) and good wave-transparent property (dielectric constant<1.45, loss tangent<0.01 in 4–18 GHz). All of these characteristics are related to the unique nanoporous structure of SiO 2 aerogel and intrinsic nature of SiBNO fibers and SiO 2 aerogel. The prepared multifunctional SiBNO f /SiO 2 ACs have great potential to be used in harsh environment for thermal insulation and wave-transparent.
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高影响因子
ACS Applied Bio Materials
·
2021
·
IF 0
Menghui Wan,Haodong Zhao,Lichao Peng,Yanbao Zhao,Lei Sun
The fabrication of highly active and free-standing surface-enhanced Raman scattering (SERS) substrates in a simple and low-cost manner has been a crucial and urgent challenge in recent years. Herein, SiO2 nanofiber substrates modified with size-tunable Ag nanoparticles were prepared by the combination of electrospinning and in situ chemical reduction. The results demonstrate the presence and uniform adsorption of Ag nanoparticles on the SiO2 matrix surface. The free-standing composite nanofibrous substrates show high-performance SERS response toward 4-mercaptophenol and 4-mercaptobenzoic acid, and the detection limit can be as low as 10–10 mol/L. Most importantly, the as-prepared substrate as a versatile SERS platform can realize label-free detection of bio-macromolecules of bacteria, i.e., Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Furthermore, the substrates also possess outstanding antibacterial activities against S. aureus and E. coli. Briefly, the significance of this study is that size-tunable Ag nanoparticles can be decorated on SiO2 nanofiber surfaces with triethanolamine as a bridging and reducing agent through a one-pot reaction, and the as-prepared nanofibrous membranes are expected to act as a candidate for label-free SERS detection as well as antibacterial dressing.
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危险品化学品经营许可证（带存储）