JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Shi-Bin Qin,Yu-Han Fan,Xiao-Xuan Mou,Xiao-Shui Li,Shi-Hua Qi
Accurate analysis of polycyclic aromatic hydrocarbons (PAHs) in soils remains a challenge due to the complexity of sample matrices. In this paper, phenyl-modified magnetic mesoporous silica (Fe 3 O 4 @mSiO 2 -Ph-PTSA) was synthesized with p-toluenesulfonic acid (PTSA) as the catalyst and used as a selective adsorbent for the clean-up of PAHs extracted from soils. The material prepared without PTSA as the catalyst (Fe 3 O 4 @mSiO 2 -Ph) was synthesized for comparison. The synthesized materials were first systematically characterized and evaluated. It was found that the grafting amount of the phenyl group onto Fe 3 O 4 @mSiO 2 -Ph-PTSA was higher than that onto Fe 3 O 4 @mSiO 2 -Ph. The extraction efficiency obtained by extracting PAHs from the extracted soil matrix solution demonstrated that Fe 3 O 4 @mSiO 2 -Ph-PTSA possessed a much higher extraction efficiency than that of Fe 3 O 4 @mSiO 2 -Ph, which can be attributed to the greater amount of phenyl groups grafted on Fe 3 O 4 @mSiO 2 in the presence of the PTSA catalyst. Moreover, contrast experiments showed that Fe 3 O 4 @mSiO 2 -Ph-PTSA displayed higher selectivity towards PAHs than towards n-alkanes and that the π-π interaction played a key role in the adsorption process. In the presence of the soil extract matrix, the parameters affecting the extraction efficiency of Fe 3 O 4 @mSiO 2 -Ph-PTSA for PAHs were optimized. Under the optimal conditions, coupled with pressurized liquid extraction and gas chromatograph-mass spectrometer, the proposed method for the determination of PAHs in soils was linear in the range of 5–500 ng g −1 , and the correlation coefficients (R) ranged between 0.9994 and 0.9999. The limits of detection (LODs) and limits of quantification (LOQs), which were based on signal-to-noise ratios of 3 and 10, respectively, were in the range of 0.07–0.41 ng g −1 and 0.24–1.37 ng g −1 . The developed method displayed a better clean-up effect than that for silica gel column method, and the matrix effect markedly decreased compared to that of the uncleaned condition. Finally, the developed method was successfully applied for the detection of PAHs in environmental soils, and the data were consistent with the results obtained by the silica gel column method. The analytical results were also consistent with those for the real environment.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2016
·
IF 3.782
Jianwei Fan,Xiaomin Wang,Wei Teng,Jianping Yang,Xianqiang Ran,Xiao Gou,Nan Bai,Menghua Lv,Huawei Xu,Guangming Li,Weixian Zhang,Dongyuan Zhao
Phthalate esters (PAEs) are a group of endocrine disrupting compounds , which have been widely used as plasticizers . To alleviate the environmental and health threats from water resources polluted by PAEs, we prepared phenyl functionalized mesoporous silica materials (ph-SBA-15) were synthesized by a simple post-modification approach for rapid and efficient removal of low concentration of di- n- butyl phthalate (DBP) from aqueous solution. Mesostructure, texture, surface chemistry and surface charges were systemically characterized. The obtained ph-SBA-15 possesses a highly ordered mesostructure, a high surface area (418 m 2 /g), uniform mesopores (6.5 nm) and high-density organic groups around 11 wt.%. Batch adsorption experiments revealed that phenyl modified SBA-15 had an excellent ability to remove DBP with the maximum adsorption capacity up to ∼40 mg/g at 25 °C. The thermodynamics and kinetics for the adsorption were also investigated, demonstrating an exothermic, multi-layer and fast adsorption process . In addition, DBP adsorption was found to be sensitive to the pH and the uptake was observed to be greatest at around pH 7.0. Furthermore, this material can be effectively regenerated by ethanol.
研究领域:
环境科学
·
材料科学
·
污染控制
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wenxia Sima,Wenlong Pang,Potao Sun,Tao Yuan,Ming Yang,Xiaoxiao Chen,Zhaoping Li,Xiaotong Liu,Xinyu Tang
The stacked aromatic rings in bisphenol A epoxy resins provide good mechanical properties and thermal stability while leading to the transport of conjugated delocalized electrons, which dramatically affects the insulation properties of the material. This contradiction leads to performance bottlenecks in epoxy-based encapsulation materials, further limiting the development of high-voltage semiconductor devices. In this study, fluorophenyl-modified epoxy monomers (FPMEPs) are designed to enrich the intermolecular interactions in an aromatic system while inhibiting the charge transport process, thereby solving the contradiction between the electrical and mechanical properties. Firstly, FPMEP with high insulation properties was designed by theoretical calculations and then synthesized by highly selective click chemistry. The fluorophenyl modulates the molecular orbitals of epoxy monomers and acts as a deep trap to inhibit charge injection and transport processes. Further, the π-π F stacking between the aromatic system and fluorophenyl enhances the interaction of the matrix molecules and solves the dispersion problem of fluorinated graphene (FG) fillers. The FPMEP/FG composites thus exhibit a considerable improvement in electrical and mechanical properties (breakdown strength of 39.8 kV/mm, dielectric loss of 0.011@50 Hz, tensile strength of 68.8 MPa, and adhesive strength of 2.15 MPa), and demonstrate good water repellency and aging durability. This matrix-filler synergistic modification strategy provides new insights into the design of insulation material.
研究领域:
材料科学
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电气工程
·
化学工程
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产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2024
·
IF 4.8
Kai Zhang,Ruili Song,Ning Wu,Yunhu Wang,Mingming Zhang,Xilei Chen,Lei Wang,Jun Xing
Graphitic carbon nitride (g-CN) materials exhibit attractive optoelectronic physical properties; however, their low photoluminescence quantum yields (PLQYs) limit their applications in luminescent devices. Here, boron-doped aromatic carbon nitride (B-PhCNx) was synthesized for the first time via direct thermal polymerization of 2,4-diamino-6-phenyl-1,3,5-triazine and boric acid. The impact of B doping and phenyl modifying on the structural and optical characteristics of the samples was investigated in detail. The highest PLQY of 40.7% was achieved in B-PhCN20, which is 6.8 times that of pristine carbon nitride (p-CN). The B-PhCN20-based light-emitting diode demonstrates a maximum luminance of 1494 cd m–2 and a maximum external quantum efficiency of 1.03%, which are 3.5 and 4.9 times that of the p-CN-based device, respectively. Our findings will provide a reference for rationally designing low-cost and high-performance carbon-nitride-based optoelectronic devices.
研究领域:
材料科学
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光电子学
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纳米技术
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物理化学
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 3
·1-8
·
IF 6.232
Mei He,Shu Huawei,Lv Mengyu,Liu Wei,Wang Xuedong
Phenyl-modified graphitic carbon nitride nanosheets (Ph- g -C 3 N 4 NSs) were synthesized by a thermal copolymerization and ultrasonic exfoliation method. The Ph- g -C 3 N 4 NSs are used as a fluorescent assay for determination of thiram. The results of X-ray photoelectron spectroscopy, 13 C solid-state nuclear magnetic resonance and Fourier transform infrared spectra confirm that phenyl group is integrated into the heptazine network of g -C 3 N 4 . Compared to the g -C 3 N 4 NSs, the Ph- g -C 3 N 4 NSs show bigger stokes shift about 185 nm and higher fluorescence intensity. The fluorescence of Ph- g -C 3 N 4 NSs is quenched by Cu 2+ via the photo-induced electron transfer mechanism, which then recovers in the presence of thiram. The fluorescence restoring of Ph- g -C 3 N 4 NSs is correlated with the concentration of thiram. Under the optimized conditions, the fluorescent intensity of g -C 3 N 4 NSs at excitation/emission wavelengths of 310/455 nm give a linear range of 33.0–670 nM with detection limit of 9.90 nM. While fluorescent assay based on the Ph- g -C 3 N 4 NSs show the linear range of 6.70–1300 nM at excitation/emission wavelengths of 310/495 nm with detection limit of 2.01 nM.
Schematic representation of fluorescent “on-off-on” assay based on phenyl-modified graphitic carbon nitride nanosheets (Ph- g -C 3 N 4 NSs) for determination of thiram.
研究领域:
材料科学
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分析化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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