CEMENT AND CONCRETE RESEARCH
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2021
·
IF 10.933
Xueyu Pang,Lijun Sun,Fang Sun,Ge Zhang,Shenglai Guo,Yuhuan Bu
The heat evolution during the hydration of cement was examined by multiple calorimetric methods: isothermal , oscillating isothermal, as well as temperature scanning tests in the temperature range from 15 °C to 95 °C. The apparent activation energy ( E a ) of several different types of cements were all found to decrease significantly with temperature. Type of additives and water to cement ratio had little influence on the temperature dependence of E a . The correlation between E a and temperature may be mathematically simplified to a step function, where E a is a nonzero constant below a critical temperature ( T cr ) and reduces to zero above that temperature. The proposed model of E a was combined with a scale factor model to simulate the influence of curing temperature on the hydration kinetics of cement with significantly improved accuracy compared to an earlier model.
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CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Fazle Subhan,Sobia Aslam,Zifeng Yan,Ayaz Ahmad,U.J. Etim,Muhammad Naeem,Liu Zhen,Muhammad Ikram,Muhammad Yaseen
Lanthanum based adsorbents are promising in adsorptive desulfurization due to high activity. The dispersion degree of La 2 O 3 impacts desulfurization performance directly, and the development of an efficient strategy for La 2 O 3 dispersion still remained challenge. Herein, for the first time confined spaces and silanols of as-synthesized SBA-15 were used for dispersion of La 2 O 3 over mesoporous silica. The La(NO 3 ) 3 precursor is directly introduced into the confined spaces between silica walls and template of as-synthesized SAB-15 by solid state dispersion (SSD) strategy. The SSD strategy assists the formation of small sized La 2 O 3 with excellent dispersion after La precursor decomposition by the combined action of confined spaces and silanols. We also demonstrated that up to 20 wt% La 2 O 3 can be highly dispersed over as-synthesized SBA-15 (LaAS-20). Our investigations show that well-dispersion of La 2 O 3 correspond to high desulfurization activity for fuels, and the amount of thiophene captured can reach 0.12 mmol of S/g over LaAS-20, which is better than that over LaCS-20 and other La-doped reported sorbents. Furthermore, LaAS-20 adsorbent showed good stability and regeneration ability, and has potential applications to be applied in adsorptive desulfurization technology.
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OPTICAL MATERIALS
·
2018
·
IF 2.32
Zhongyu Wang,Ying Li,Hao Hu,Xia Wang
Novel organic-inorganic mesoporous luminescent polymeric composite materials containing lanthanide (Eu 3+ , Tb 3+ ) complexes covalently bonded to mesoporous silica have been prepared in situ, followed by the polymerization reaction of the monomer 4-vinylphenylboronic acid (VPBA) extending along the mesoporous SBA-15 channels. The obtained materials were investigated by Fourier transform infrared spectroscopy (FT-IR), Ultraviolet absorption spectra (UV), X-ray diffraction (SAXRD), N 2 adsorption/desorption isotherms, Transmission electron microscopy (TEM), thermogravimetry (TG), and luminescence spectroscopy in detail. These characterizations have proved that composite materials possess high surface area, uniform mesoporous structure, good crystallization and relatively excellent luminescence properties. The terminal ligand phen was used to investigate the difference of photo physical and luminescent properties between binary and ternary composite materials. Furthermore, the results have revealed that the composite material Eu(PVPBA-S15) 3 phen showed more efficient intramolecular energy transfer between the europium ion and the ligands, and more excellent characteristic emission of the europium ion under UV irradiation with higher 5 D 0 luminescence quantum efficiency than the composite materials Eu(PVPBA-S15) 3 without phen. The excellent luminescence properties and ordered mesoporous structures could give rise to many potential applications in optical and electronic areas.
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FUEL
·
2016
·
IF 3.611
Xiaoling Ren,Guang Miao,Zhiyong Xiao,Feiyan Ye,Zhong Li,Haihui Wang,Jing Xiao
This study investigates catalytic adsorptive desulfurization (CADS) of model diesel fuel using TiO 2 /SBA-15 under mild conditions. The TiO 2 /SBA-15 was prepared by a facile incipient wetness impregnation method and characterized by N 2 adsorption and X-ray diffraction. The CADS referred to ADS performance were evaluated in a batch reactor. High desulfurization uptake of 12.7 mg/g was achieved at low sulfur concentration of 15 ppmw-S by TiO 2 /SBA-15 under CADS, which was two-magnitude higher than that under ADS without the in-situ catalytic oxidation of dibenzothiophene. Kinetic results suggested that the CADS equilibrium over TiO 2 /SBA-15 was reached fast in 0.5 h. In the CADS–TiO 2 /SBA-15 system, the TiO 2 loading, cumene hydroperoxide/dibenzothiophene ratio and CADS temperature were optimized to be 10 wt%, 2, and 35 °C, respectively. Furthermore, desulfurization tests in 5 consecutive CADS-regeneration cycles suggested that the bi-functional TiO 2 /SBA-15 can be regenerated by acetonitrile washing followed with oxidative air treatment. The CADS–TiO 2 /SBA-15 mechanism went through the oxidation of DBT to oxidized DBTO 2 over TiO 2 /SBA-15 by cumene hydroperoxide, which was followed by the adsorption of the oxidized DBTO 2 over TiO 2 /SBA-15. The superior desulfurization uptake at low sulfur concentration range, fast adsorption kinetics, excellent regenerability, operation at mild conditions, and facile and low-cost adsorbent synthesis make the CADS–TiO 2 /SBA-15 system an effective and economic desulfurization approach for ultra-clean fuel production.
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高影响因子
JOURNAL OF POROUS MATERIALS
·
2016
·Vol. 23
·期 3
·823-831
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IF 1.385
Yuan Junjie,Xiong Jun,Wang Jiahong,Ding Wenjing,Yang Lei,Zhang Ming,Zhu Wenshuai,Li Huaming
A supported catalyst was synthesized on the mesoporous materials with ionic liquid modified by the silicontungstic acid (HSiW-IL/SBA-15). A series of characterization, such as XRD, N 2 adsorption desorption, SEM, TEM and XPS analysis showed that HSiW was successfully immobilized onto the IL modified SBA-15 and maintained the SBA-15 mesoporous structure. Compared with HSiW and HSiW/SBA-15, the catalyst HSiW-IL/SBA-15 had excellent catalytic activity for oxidative desulfurization of fuels. After analysis, the high activity of HSiW-IL/SBA-15 was attributed to the catalyst with large specific surface area, pore size and hydrophobic performance, which had a better wettability for fuel. The catalyst had a good recycling performance, and the sulfur removal still remained 96.4 % after eight times cycle.
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JOURNAL OF MOLECULAR LIQUIDS
·
2017
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IF 3.648
Jiang Xiao,Yongzhong Jia,Chenglong Shi,Xingquan Wang,Su Wang,Ying Yao,Yan Jing
A green and efficient liquid–liquid extraction system was developed for the separation of lithium isotopes by using hydrophobic ionic liquids (ILs = [C 4,6,8,10 mim] + [NTf 2 ] − ) as extraction organic phase and benzo-15-crown-5 (B15C5) as complexing agent. The maximum single-stage separation factor α of 6 Li/ 7 Li obtained in this study was 1.029 ± 0.001, indicating 6 Li was enriched in ionic liquid phase while 7 Li was concentrated in the aqueous phase. The lithium ion was extracted into the ionic liquid in the formation of 1:2 complex [Li + (B15C5) 2 ]. The negative data of thermodynamic parameters (∆ H 0 and ∆ G 0 ) suggest that the extraction system was a spontaneous exothermic process . In addition, effective lithium isotopes separation factor and the extraction efficiency of lithium ions can be gained in the condition of lower temperature with softer counter anions in the novel extraction system.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 52
·41377-41384
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IF 3.84
Xiaoli Gu,Hongliang He,Chong-zhi Wang,Yankun Gao,Hongjuan Zhang,Junli Hong,Shuhu Du,Lina Chen,Chun-su Yuan
Surface molecularly imprinted polymers (MIP@SBA-15) imprinted on the surface of hybrid nanostructured organic/inorganic materials (SBA-15) were prepared for the selective extraction and detection of baicalin (BA) in biological samples. The surface morphologies and characteristics of the imprinted and non-imprinted polymers were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and nitrogen adsorption–desorption isotherms. The results indicated that the polymers were successfully grafted onto the surface of SBA-15 and possessed a highly ordered mesoporous structure. In binding tests, MIP@SBA-15 reached saturated adsorption within 80 min and exhibited significant specific recognition toward BA with a large adsorption capacity. In addition, the prepared MIP@SBA-15 was used as a selective sorbent for solid-phase extraction of BA from biological samples. Recoveries of BA from the liver and spleen ranged from 90.6% to 90.9% with RSD <3.7%. All these results reveal that this method is simple, rapid and sensitive for effectively extracting and detecting trace BA in biological samples.
研究领域:
分析化学
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药物分析
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材料科学
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PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2012
·
IF 2.234
Dayu Wu,Zhuqing Wang,Genhua Wu,Wei Huang
Mesoporous silica material, SBA - 15 , is an excellent support for constructing fluorescent surface sensor. In this paper, we reported a three-step surface reaction involved strategy to construct efficient fluorescent surface sensor for mercury ion by clicking rhodamine fluoroionophores onto APES-functionalized SBA - 15 , which is fully characterized by IR spectra , TGA analysis, elemental analysis , nitrogen adsorption experiment and TEM . Our experimental results indicated that such a strategy exhibits an obviously higher loading efficiency within SBA - 15 than a previously reported strategy. The Hg 2+ extracting efficiency for SBAIR was found to be enhanced ( ca . 89%). In addition to the high selectivity , the current chemosensor shows improved sensitivity and can respond to Hg 2+ as low as ppb level (1.0 × 10 −8 M, 2 ppb) in water.
研究领域:
分析化学
·
环境科学
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高影响因子
ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
Yuyan Hu,Boxue Wu,Ying-Shu Tang,Yi Wu,Li-Yan Liu
Background Sugar phosphates (SPx) play important role in the metabolism of the organism. SPx such as glycerate 3-phosphate, fructose 6-phosphate and glucose 6-phosphate in biological samples have the poor stability, similar structure and low abundance, which make their separation and detection more challenging. Method UiO-66-NH 2 and ZrO 2 coated SiO 2 (SBA-15) hard-core–shell adsorbents (UiO-66-NH 2 @SBA-15 and ZrO 2 @SBA-15) were synthesized, which were further used for dispersive solid-phase extraction for enriching the SPx in biological samples. The protocol was developed by UiO-66-NH 2 @SBA-15 and ZrO 2 @SBA-15 coupled with gas chromatography-mass spectrometry for the detection of trace SPx. The univariate experiment and response surface methodology were used to optimize the adsorption and desorption conditions. Results The adsorbents showed excellent adsorption capacity and specificity towards SPx, which were proved by adsorption and selective experiments. Under the optimized conditions, there were good linearity within the range of 5.0–5000.0 ng mL −1 , low limits of detection (0.001–1.0 ng mL −1 ), low limits of quantification (0.005–5.0 ng mL −1 ) and good precision (relative standard deviation less than 14.7 % for intra-day and inter-day). The satisfactory recoveries (89.1–113.8 %) and precision (0.5–14.6 %) were obtained when the sorbents were used to extract SPx from serum, saliva and cell samples. Moreover, UiO-66-NH 2 @SBA-15 was applied to the quantitative analysis of SPx from gastric cancer patients, because of a higher adsorption capacity (169.5–196.1 mg g −1 ). Conclusions UiO-66-NH 2 @SBA-15 showed great potential in the extraction of SPx in biological samples, which was beneficial to find out the metabolic change of SPx and explain the pathogenesis of the disease.
研究领域:
分析化学
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生物化学
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医学
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PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 29
·13038-13047
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IF 2.7
Ni Yan,Long-Hui Duan,Min He,Wen Luo,Zhitong Ou,Jing Wang
The extensive use of sulfonamide antibiotics (SAs) proved to be harmful to humans and the environment; thus, the treatment of SAs in water is imminent. In this work, mesoporous SBA-15 silicon was modified using N-[3-(trimethoxysilyl)propyl]ethylenediamine (AAPTMS) through the formation of AAPTMS-SBA-15. The adsorption performance of AAPTMS-SBA-15 toward sulfamethizole (SIZ) was investigated in the absence and presence of various metal ions, and the results reveal that the introduction of Ni2+ substantially improved the adsorption capacity for SIZ. To maximize the adsorption performance toward SIZ, AAPTMS-SBA-15 was then combined with the heavy metal Ni2+ to prepare Ni-AAPTMS-SBA-15. Subsequently, the adsorption performance and behavior of Ni-AAPTMS-SBA-15 were studied in terms of pH, adsorbent dosage, kinetics, isothermal adsorption, and thermodynamics. SIZ exhibited spontaneous and exothermic adsorption on Ni-AAPTMS-SBA-15, which rapidly reached equilibrium within 2 min; the maximum adsorption capacity was 188.68 mg g−1 at pH = 5.0 and adsorbent dosage of 8 mg. The effective adsorption of SIZ was attributed to the combined mechanisms of electrostatic interaction, complexation and pore-filling.
研究领域:
环境科学
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材料科学
·
药学
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高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 3
·期 8
·4307-4313
·
IF 0
Xianchun Liu,Renxi Jin,Dashu Chen,Lin Chen,Shuangxi Xing,Hongzhu Xing,Yan Xing,Zhongmin Su
In this study, we report a simple in situ auto-reduction strategy for the fabrication of Ag@FDU-15 nanocomposites, in which the small sized Ag nanoparticles are monodispersed in the channels of FDU-15 ordered mesopolymers. The as-prepared Ag@FDU-15 nanocomposites were characterized by small and wide angle X-ray diffraction (XRD), nitrogen sorption, thermo-gravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). TEM results show that the silver nanoparticles are uniformly dispersed with a mean diameter of 5.6 ± 0.5 nm. When used as a hydrogenation catalyst, the Ag@FDU-15 nanocomposites exhibit excellent catalytic performance and reusability for the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4.
研究领域:
材料科学
·
催化化学
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Nature Energy
·
2026
·
IF 70.1
Cui Changcheng,Li Yimeng,Wei Hao,Du Xiaofan,Shao Zhipeng,Kou Dongxing,Wu Zucheng,Xia Shengren,Feng Xiaopeng,Pang Shuping,Wang Xiao,Mao Sui,Xin Hao,Wu Sixin,Cui Guanglei
The selenization reaction process is the key step in determining the quality of Cu 2 ZnSn(S,Se) 4 thin films. Imbalanced migration kinetics of metal ions during selenization led to high concentrations of deep-level defects, resulting in dramatic open-circuit voltage loss. In this work, we reported a Li 2 SnS 3 interphase strategy to modify cation migration paths and balance Zn 2+ /Sn 4+ migration differences. The Li 2 SnS 3 interphase selectively encapsulates the Cu 2 Sn(S,Se) 3 intermediate grains, serving as the rate-determining layer for ion migration. The Zn 2+ /Sn 4+ migration barrier difference in the interphase decreases from 0.41 eV in Cu 2 Sn(S,Se) 3 to 0.21 eV in Li 2 SnS 3 , which promotes the formation of larger, uniform, high-crystallinity grains. As a result, device efficiency improves from 13.86% to 15.45% (certified at 15.04%), and open-circuit voltage reaches 602 mV at a bandgap of 1.10 eV.
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