ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2022
·Vol. 30
·期 8
·20006-20019
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IF 5.19
Lin Qinghua,Hong Mei
Fractional wettability is common in the dense non-aqueous phase liquids (DNAPL) contaminated sites. However, it is still unclear how fractional wettability affects surfactant-enhanced DNAPL immiscible mobilization in saturated porous media. The macro-contact angle of the fractional wettability media was measured. The results of column experiments showed that the entrapped tetrachloroethene (PCE) saturations after sodium dodecyl benzene sulfonate (SDBS) flooding were lower in the media where NAPL-wet sand was present compared with those in water-wet media. In the media which contained 25% octadecyltrichlorosilane (OTS)-treated sand, the entrapped PCE saturations decreased to the minimum, and the decrease was much larger in fine sand media. The SDBS-enhanced PCE recoveries were jointly affected by fractional wettability, particle size, and interfacial tension (IFT). When NAPL-wet sand was present and SDBS concentration was just 0.125 g⋅L −1 , the SDBS-enhanced PCE recoveries increased significantly. As the SDBS concentration continues to increase to 0.5 g⋅L −1 , they only increased slightly. In the fine sand media, the SDBS-enhanced PCE recoveries were higher, and they increased more obviously with the increase of NAPL-wet sand fractions. The influence weight of fractional wettability on SDBS-enhanced PCE recoveries was the largest (47.09%) under the experimental conditions. These findings indicate that it is important to consider fractional wettability characteristics when establishing a DNAPL immiscible mobilization strategy, because it is not sufficient to consider only IFT reduction, especially in media with finer pore structures.
研究领域:
环境科学
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化学工程
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水文地质学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Zhouwei Miao,Xiaogang Gu,Shuguang Lu,Dionysios D. Dionysiou,Souhail R. Al-Abed,Xueke Zang,Xiaoliang Wu,Zhaofu Qiu,Qian Sui,Muhammad Danish
The performance of chelated Fe(II)-based catalyzed sodium percarbonate (SPC) stimulating the degradation of perchloroethylene (PCE) in aqueous solution was investigated using six different chelating agents (CA), namely, citric acid monohydrate (CIT), oxalic acid (OA), l -ascorbic acid (ASC), ethylenediaminetetraacetic acid (EDTA), trisodium citrate 2-hydrate (CIT-Na 3 ), and EDTA-Na 2 , at CA/Fe(II)/SPC/PCE molar ratios of 2/4/4/1, 4/4/4/1 and 8/4/4/1. The results indicated that the addition of CIT and OA significantly enhanced the PCE degradation. In addition, investigations using free radical probe compounds and radical scavengers revealed that PCE was primarily degraded by HO radical oxidation in Fe(II)/SPC, CIT/Fe(II)/SPC, and OA/Fe(II)/SPC systems and O 2 − also participated in the degradation of PCE in CIT/Fe(II)/SPC and OA/Fe(II)/SPC systems. The intensity of HO detected by electron paramagnetic resonance (EPR) in CIT/Fe(II)/SPC and OA/Fe(II)/SPC systems indicated that the addition of CIT or OA indeed enhanced the continuous production of HO and enabled the intensity of HO to be more stable. The results demonstrated that CIT and OA significantly improved the PCE degradation efficiency by increasing the concentration of Fe(II) and maintaining the concentration of HO radicals in solution. In conclusion, chelated Fe(II)-based catalyzed SPC oxidation process shows enormous practical prospects for the remediation of PCE-contaminated groundwater because of the effectiveness without pre-adjusting the solution pH and complete mineralization in Fe(II)/SPC, CIT/Fe(II)/SPC and OA/Fe(II)/SPC systems.
研究领域:
环境科学
·
化学
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DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2017
·
IF 3.169
Jinfeng Sun,Hu Shi,Binbin Qian,Zhiqiang Xu,Weifeng Li,Xiaodong Shen
This work investigates the influence of synthetic C-S-H/polycarboxylate(PCE) nanocomposites (CPNs) on the hydration and properties of hydrated cement pastes. HPEG-PCE copolymers exhibiting side chain length of 45 ethylene oxide (EO) units was utilized to synthesize CPNs by precipitating C-S-H from Na 2 SiO 3 and Ca(NO 3 ) 2 in the PCE solution. A Box-Behnken Design (BBD) for the Response Surface Methodology (RSM) was employed to statistically optimize the sizes of the resultant. The prepared CPNs were characterized by particle size distribution (PSD), X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR) and thermo gravimetric/derivative thermo gravimetric (TG/DTG) analyses. The influence of CPNs on the hydration properties of cement were assessed and discussed in terms of hydration kinetics, mechanical properties, phase composition and pore structure analysis. The experimental results showed that the optimum synthetic parameters, an experimental temperature of 30.1 °C, reactant flow velocity of 0.63 ml/min and initial volume of PCE solution of 28.5 ml, produced CPNs with a minimum size of 329.12 nm. It was demonstrated that PCE polymers were either grafted on the surface or partially intercalated in the interlayer regions of C-S-H, and their introduction also increased the distance between C-S-H interlayers. Cement hydration was significantly promoted as a result of an increased heat release, even at low CPNs content. The early compressive strength of the mortar significantly improved with increasing CPNs content due to the accelerated cement hydration of the CPNs: the 0.6 wt.% CPNs content improved the compressive strength by 18.97%. Moreover, the inclusion of CPNs is advantageous for pore modification: the total porosity decreased by 25.77% after 3 days. Finally, phase composition analysis confirmed that no new crystalline phase was produced upon CPNs addition.
研究领域:
建筑材料科学
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化学工程
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DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Kaifeng Wang,Yuxun Kan,Yunsheng Zhu,Kaihong Zhong,Jiabing Hu
Calcium silicate hydrate (C-S-H) is considered a novel early strength agent, showing immense potential in enhancing the early strength of cement-based materials. Polycarboxylate (PCE) is widely used as a dispersant in the synthesis of nano-C-S-H to prevent agglomeration during synthesis. However, a comprehensive investigation is still required to establish a stable method for preparing stable C-S-H/PCE nanocomposites using chemical co-precipitation. This study employed orthogonal experiments, range analysis, variance analysis, and multi-index matrix analysis to explore the effect of the chemical co-precipitation synthesis process on the stability of C-S-H/PCE nanocomposites. It conclusively identified the calcium-to-silicon (C/S) ratio as the sole significant influencing factor, establishing optimal synthesis parameters: a C/S ratio of 1.6, stirring at 8000 r/min, a 2-hour reaction time, and a reaction temperature of 30 °C. Additionally, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to investigate the impact of the C/S ratio on the structure and morphology of C-S-H/PCE nanocomposites. Results indicated that under the optimal synthesis parameters, the average particle size and precipitation rate of the synthesized C-S-H/PCE nanocomposites were 0.122 µm and 0.44%, respectively, exhibiting a 4.7% and 47.6% improvement over the best samples in the orthogonal test. Increasing the C/S ratio decreased the crystallinity of the C-S-H/PCE nanocomposites, resulting in the emergence of multiple crystal structures, compact and ordered morphology, and reduced sedimentation. These findings collectively underscore that C-S-H/PCE nanocomposites with higher C/S ratios exhibit enhanced dispersion and stability, validating the rationality of the optimal synthesis parameters identified in this study.
研究领域:
建筑材料学
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化学工程
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材料科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2017
·Vol. 24
·期 26
·21011-21023
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IF 2.741
Liu Yunsong,Chen Jiajun,Wang Qingwei,Shi Lanxiang,Shi Yandan
Viscosity remedial technology, which uses a water-soluble polymer mixed with remedial fluids, has been introduced in recent years to improve the removal efficacy of perchloroethylene/tetrachloroethylene (PCE) by improving oxidant coverage (i.e. sweep efficiency). Xanthan gum and hydrolysed polyacrylamide (HPAM) are relatively stable with time and temperature and possess salt and oxidation resistance, indicating that they may be good flooding agents (the former is better than the latter in this work). In this work, we quantified the polymer directly improved oxidation of PCE during transport by using a two-dimensional flow tank. Using a low pore volume (≤3.0), the removal rate of the PCE increased with the polymer concentration before stabilizing at approximately 93.00 and 88.30% for xanthan and HPAM, respectively. In this work, over 80% of PCE was removed via less than 3.0 PV of the SDS solution, whereas complete removal (100%) was achieved with less than 3.0 PV of SDS foam. Furthermore, the new experimental discoveries demonstrate that xanthan is better than HPAM and SDS foam is a better remediation agent than the SDS solution for removing PCE.
(Reaction device, A - inlet device (pump 1#), B - 2D tank, C - outflow device (pump 2#), D - data recording and processing device, E - microscopic expression, E (a) - KMnO 4 flushing, E (b) - polymer solution flushing).
研究领域:
环境科学
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化学工程
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土壤修复
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Rong Chen,Zhiting Liu,Tingting Cui,Xiaoying Zhang,Cai-Feng Wang,Guo-Xing Li,Gefei Wang,Su Chen
Hydrogels have attracted increasing attention in the biomedical field due to their similarity in structure and composition to natural extracellular matrices. However, they have been greatly limited by their low mechanical strength and self-adhesion for further application. Here, a gel-nanofiber material is designed for wound healing, which synergistically combines the benefits of hydrogels and nanofibers and can overcome the bottleneck of poor mechanical strength and self-adhesion in hydrogels and inadequate healing environment created by nanofibers. First, a nanofiber scaffold composed of polycaprolactone/poly(citric acid)-ε-lysine (PCL/PCE) nanofibers is fabricated via a new strategy of microfluidic electrospinning, which could provide a base for hyaluronic acid-polylysine (HE) gel growth on nanofibers. The prepared HE@PCL/PCE gel-nanofiber possesses high tensile strength (24.15 ± 1.67 MPa), excellent air permeability (656 m3/m2 h kPa), outstanding self-adhesion property, and positive hydrophilicity. More importantly, the prepared gel-nanofiber dressing shows good cytocompatibility and antibacterial properties, achieving a high wound-healing rate (92.48%) and 4.685 mm granulation growth thickness within 12 days. This material may open a promising avenue for accelerating wound healing and tissue regeneration, providing potential applications in clinical medicine.
研究领域:
生物医学工程
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材料科学
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组织工程
·
伤口愈合
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产品关联
DOI
PubMed
高影响因子
Journal of Sustainable Cement-Based Materials
·
2026
·
IF 3.6
Shengnan Sha,Yuhui Lyu,ChunHeung Chan,Hailong Ye
The dispersing efficiency of polycarboxylate ether (PCE) superplasticizers is substantially compromised in alkali-activated cementitious systems containing carbonate ions (e.g. alkaline carbonates as activators), even in the absence of solubility constraints. This loss of plasticization performance mainly stems from competitive adsorption of carbonate ions (CO32−) at particle surfaces and conformational collapse of PCE macromolecules. To distinguish and quantify their respective impacts, we employed the YODEL (Yield Stress mODEL) and symbolic regression on limestone suspensions containing systematically varied K2CO3 and PCE dosages. Results reveal that K2CO3 induces an exponential decrease in surface coverage of PCE by blocking effective adsorption sites, while simultaneously causing a linear reduction in the viscosimetric size of PCE macromolecules. Importantly, the yield stress across the K2CO3 concentration range (<190 g/L) is predominantly governed by reductions in effective surface coverage rather than steric hindrance losses from collapse of PCE macromolecules.
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2026
·
IF 4.8
Atinafu Abayneh Sebaro,Gang Cao,Qiyu Zhou,Minggao Xu,Chengyuan Liu,Yang Pan
Online SR-PIMS enables real-time detection of gaseous photocatalytic products. • Gas-phase products formed during PCE photocatalysis over TiO 2 were identified. • Oxygen promotes oxidative dechlorination and mineralization of PCE. • Water redirects chlorine chemistry toward HCl and HOCl formation. • A photocatalytic degradation pathway is proposed based on identified products. Tetrachloroethylene (PCE) is a fully chlorinated ethene whose photocatalytic transformation involves coupled carbon oxidation and chlorine-release processes. Although gas-phase PCE photocatalysis over TiO 2 has been investigated using conventional analytical techniques, the evolution of gaseous products and the effects of reaction atmosphere remain incompletely resolved. In this study, online synchrotron radiation photoionization mass spectrometry (SR-PIMS) was employed to investigate the photocatalytic degradation of gaseous PCE over TiO 2 under 360 nm LED irradiation. Photoionization efficiency (PIE) analysis enabled the identification of CO, CO 2 , Cl 2 , COCl 2 , HCl, and HOCl as major gaseous products. Signals tentatively assigned to C 2 OCl 3 and C 2 Cl 5 were also observed, although their neutral precursors could not be unambiguously established. Systematic variation of the reaction atmosphere revealed distinct effects of O 2 and H 2 O on the observed product chemistry. Increasing O 2 availability was accompanied by a decrease in the PCE signal and increased formation of CO 2 , COCl 2 , and Cl 2 , consistent with enhanced oxidative transformation and dechlorination under the investigated conditions. In contrast, the introduction of water vapor resulted in the appearance of HCl and HOCl, while no obvious change in PCE signal intensity was observed between the dry and humid aerobic experiments. These observations indicate that O 2 and H 2 O influence different aspects of PCE photocatalytic transformation, with O 2 affecting the observed conversion and oxidation/dechlorination products and H 2 O primarily affecting chlorine-product speciation. The results provide experimentally based constraints on possible PCE degradation pathways under the investigated low-pressure conditions. Download: Download high-res image (98KB) Download: Download full-size image
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2026
·
IF 10.6
Sulin Wang,Jian Xu,Fei Wang
Phase-resolved mass balances reveal aqueous PCE rebound during net PCE removal. • Rapid Fe(II) consumption weakens oxidation despite residual persulfate. • Fe-rich deposition and altered organic groups support changes in PCE retention. • Delayed PCE release outpaces effective oxidation, creating a kinetic mismatch. Ferrous iron-activated persulfate (Fe(II)/PDS) is widely used for in situ chemical oxidation (ISCO) of chlorinated solvents, yet aqueous rebound complicates treatment evaluation. Phase-resolved mass balances were combined with electron paramagnetic resonance (EPR) and surface characterization to examine tetrachloroethene (PCE) redistribution and removal. In homogeneous aqueous systems, PCE removal was rapid within 2 h, with rapid dissolved Fe(II) consumption. Among evaluated Fe(II):PDS ratios, 1:1 yielded the highest removal, with > 30% PDS persisting beyond the initial stage. Following Fe(II)/PDS addition to pre-equilibrated soil–water systems, aqueous PCE increased while soil-associated PCE decreased and total PCE mass declined monotonically. SEM–EDS, FTIR, and XRD indicated Fe-rich surface deposition and altered organic functional groups, supporting interfacial changes that weaken PCE retention. Soil addition attenuated EPR spin-adduct responses. In pre-equilibrated systems, the fitted sulfate-adduct response in soil extracts exhibited negligible variation between 10 and 120 min, consistent with continued soil-associated activation as intensive aqueous oxidation subsided. These observations support a kinetic mismatch between declining effective oxidative capacity and continued soil-to-water PCE release, allowing aqueous accumulation despite net removal. The findings provide a mechanistic basis for coordinating reagent transport and local activation with delayed contaminant release through alternating PDS and Fe(II) injection in groundwater circulation well (GCW) systems. Download: Download high-res image (273KB) Download: Download full-size image Mechanism of Radical‑pulse induced PCE rebound The aqueous PCE rebound observed in the investigated pre-equilibrated soil–water system is interpreted as the combined outcome of rapid initial oxidation, treatment-induced surface reconstruction, and delayed interphase mass transfer. Fe(II)/PDS activation generates an initial radical pulse involving SO 4 •− and ·OH, while dissolved Fe(II) is rapidly consumed. Reactive species can oxidize readily accessible PCE and competing soil constituents, including surface-associated organic moieties. Oxidative disturbance of SOM- and soft-carbon-associated sorption domains, together with the formation of Fe(III)-bearing surface deposits, may weaken PCE retention and reduce its immediate re-adsorption. Release from condensed SOM/hard-carbon domains and less-accessible intraparticle regions may persist as the initial aqueous oxidative activity declines. The pH evolution and relatively persistent sulfate-adduct response in soil extracts are consistent with continued soil-associated PDS activation, which may sustain slower oxidation within accessible domains. This activity, however, may not provide sufficient aqueous oxidative capacity to remove PCE at the rate of its release. Aqueous accumulation can therefore coexist with continued net PCE loss, as demonstrated by the phase-resolved mass measurements. The proposed mechanism links treatment-induced changes in contaminant retention to a kinetic mismatch between declining aqueous oxidative capacity and continued soil-to-water PCE release.
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高影响因子
Solar RRL
·
2017
·Vol. 1
·期 11
·1700149
·
IF 0
Rundong Fan,Ning Zhou,Lin Zhang,Rong Yang,Yuan Meng,Liwei Li,Tie Guo,Yihua Chen,Ziqi Xu,Guanhaojie Zheng,Yuan Huang,Liang Li,Liang Qin,Xiaohui Qiu,Qi Chen,Huanping Zhou
Recently, perovskite/Si devices have attracted enormous interest as an ideal technology for tandem cells, particularly due to the attributes from perovskite cell including low temperature processibility, tunable optical bandgap, and high open circuit voltage. Although solution process is considered to be cost effective and more widely adoptable for perovskite subcell, to the best of our knowledge, there has been no successful demonstration for the resulting high performance two-terminal perovskite/Si cells. In this manuscript, solution process is employed to fabricate the key components in the two-terminal perovskite/Si tandem solar cell, including tunneling junction and the perovskite absorber. The current density match between both cells is thoroughly studied by varing the perovskite bandgap from ≈1.55 to 1.69 eV. It was also revealed that the photovoltage modulation in the device is primarily associated to the band alignment over the perovskite and the tunneling materials. Therefore, a reverse scanned power conversion efficiency over 20% is demonstrated, the most efficient two-terminal perovskite/Si device based on solution processed perovskite subcells.
研究领域:
材料科学
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能源技术
·
光伏器件
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DOI
Advanced Science
·
2022
·Vol. 9
·期 20
·2201241
·
IF 17.521
Yubo Cui,Mengyang Wang,Peizhe Dong,Shuangshuang Zhang,Junjie Fu,Libo Fan,Chaoliang Zhao,Sixin Wu,Zhi Zheng
A main concern of the promising DMF-based Cu 2 ZnSn(S x ,Se 1- x ) 4 (CZTSSe) solar cells lies in the absence of a large-grain spanning structure, which is a key factor for high open-circuit voltage ( V oc ) and power conversion efficiency (PCE). A new strategy to achieve CZTSSe large-grain spanning monolayer is proposed, by taking advantage of the synergistic optimization with a Cu 2+ plus Sn 2+ redox system and pre-annealing temperatures. A series of structural, morphological, electrical, and photoelectric characterizations are employed to study the effects of the pre-annealing temperatures on absorber qualities, and an optimized temperature of 430 ℃ is determined. The growth mechanism of the large-grain spanning monolayer and the effect of redox reaction rate are carefully investigated. Three types of absorber growth mechanisms and a concept of critical temperature are proposed. The devices based on this large-grain spanning monolayer suppress the recombination of carriers at crystal boundaries and interfaces. The champion device exhibits a high V oc (>500 mV) and PCE of 11.76%, which are both the maximum values among DMF-based solar cells at the current stage.
研究领域:
材料科学
·
太阳能电池研究
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DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Fuyan Chen,Bowen Liu,Wei Shao,Jiaxin Gao,Chenxi Zhao,Dongdong Shen,Daocheng Pan,Xinan Shi
Compared with the traditional Mo back electrode of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells, the transparent and conductive electrode of fluorine-doped tin oxide (FTO) has the advantages of low lattice mismatch with the CZTSSe absorber, earth-abundant composition, transparency, and advanced applications in building integrated photovoltaics. Hence, the research of bifacial FTO/CZTSSe thin film solar cells has attracted more and more attention. However, the poor interface contact between n-type FTO/p-type CZTSSe prevents the improvement of power conversion efficiency (PCE) of CZTSSe thin film solar cells deposited on the FTO substrate. Therefore, back contact interface modification is an effective strategy to promote the performance of the FTO/CZTSSe solar cells. Here, we choose the solution-processed MoO3 as the interface layer to modify the interface of FTO/(Cu,Ag)2ZnSn(S,Se)4 (CAZTSSe), and systematically investigate the effects of the thickness of MoO3 interface layer on the performance of FTO/MoO3/CAZTSSe solar cells. It is found that the optimal thickness of the solution-deposited MoO3 interface layer is 30 nm. As a result, kesterite solar cells on the FTO substrate achieve a front-side PCE of 9.49 % and a rear-side PCE of 1.04%.
研究领域:
材料科学
·
太阳能
·
光伏技术
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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）