Desalination and Water Treatment
·
2016
·
IF 1.272
Jiang Haiyan,Zhao Qiuxiang,Zeng Ying
In this study, modified polyvinyl alcohol (PVA) was prepared and characterized by element analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and surface area and proximity analysis. The isotherms and thermodynamic parameters of the modified PVA adsorption process were estimated. The data indicate that the adsorption process is exothermic, feasible, spontaneous, and fit to the Langmuir isotherm model. The maximum adsorption capacities for Cd(II) and Pb(II) were calculated to be 1.19 and 1.48 mmol/g, respectively. Sorption was rapid, with the removal percentage higher than 98% after 10 min. Adsorption behavior mechanisms were analyzed using pseudo-first-order and pseudo-second-order models, which were highly fitted to pseudo-second-order model. This suggests the main adsorption mechanism is a chemical adsorption, involving ion exchange and valence forces through sharing or exchange of electrons between metal ions and modified PVA. The modified PVA is a good reusable sorbent, enhancing the economics of practical application for the removal of Cd(II) and Pb(II) from water and wastewater.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 23
·4250
·
IF 4.329
Hongchuan Dong,Yunfan Liu,Yanming Cao,Juzhen Wu,Sida Zhang,Xinlong Zhang,Li Cheng
Moisture is detrimental to the performance of epoxy resin material for electrical equipment in long-term operation and insulation. Therefore, moisture absorption is one of the critical indicators for insulation of the material. However, some relevant test methods, e.g., the direct weighing method, are time-consuming, and it usually takes months to complete a test. For this, it is necessary to have some modification to save the test time. Firstly, the study analyzes the present prediction method (according to ISO 62:2008). Under the same accuracy, the time required is reduced from 104 days to 71 days. Subsequently, the Langmuir curve-fitting method for water absorption of epoxy resin is analyzed, and the initial values of diffusion coefficient, bonding coefficient, and de-bonding coefficient are determined based on the results of molecular simulation, relevant experiment, and literature review. With the optimized prediction model, it takes only 1.5 days (reduced by 98% as compared with the standard prediction method) to determine the moisture absorbability. Then, the factors influencing the prediction accuracy are discussed. The results have shown that the fluctuation of balance at the initial stage will affect the test precision significantly. Accordingly, this study proposes a quantitative characterization method for initial trace moisture based on the terahertz method, by which the trace moisture in epoxy resin is represented precisely through the established terahertz time-domain spectroscopy system. When this method is used to predict the moisture absorbability, the experimental time may be further shortened by 33% to 1 day. For the whole water absorption cycle curve, the error is less than 5%.Keywords:epoxy resins;Langmuir;terahertz;molecular simulation;prediction
研究领域:
材料科学
·
电气工程
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DOI
PubMed
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·Vol. 333
·期 6
·2735-2744
·
IF 1.5
Liu Zengcheng,Xu Yufen
In this paper, a two-step precipitation polymerization method was used to prepare a magnetic poly(cyclotriphosphazene-co-3,3′-sulfonyl dianilide) (MPSD) as an adsorbent for the removal of the radioactive element thorium(IV) in aqueous solution. The magnetic material was characterized and analyzed by FTIR, XRD, SEM, BET and VSM. The experimental results showed that the adsorption capacity of MPSD was 286.7 mg/g when pH was 4.0. And the adsorption process fitted the Langmuir model ( R 2 = 0.9991) and the pseudo-secondary kinetic model ( R 2 = 0.9997). At the same time, the thermodynamic data indicated that the removal of thorium(IV) by MPSD microspheres was a spontaneous endothermic process.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Lytuong Tran,Pingxiao Wu,Yajie Zhu,Shuai Liu,Nengwu Zhu
A novel approach to prepare adsorbents for Hg(II) uptake from aqueous media based on the grafting of dimercaprol (BAL), containing thiol and hydroxyl groups, onto the natural montmorillonite and vermiculite was investigated concerning the evaluation of the adsorption capacity. The kinetic study showed that the adsorption process abided by pseudo-second-order model. The adsorption behavior of Hg(II) onto the obtained samples fitted well with Langmuir isotherm model, exhibiting an enhanced maximum adsorption capacity of 8.57 and 3.21 mg g −1 for BAL-Vm and BAL-Mt, respectively. The feasibility of Hg(II) uptake onto the the samples was studied thermodynamically and the calculated coefficients such as Δ H , Δ S and Δ G indicated a physical and spontaneous process. The pH values and coexisting cations had a great influence on Hg(II) removal, confirming the optimal pH value of 4.0–5.0 and the negative correlation between the ionic strength and the adsorption capacity of Hg(II). In general, BAL-Vm possessed a higher efficiency of Hg(II) uptake than BAL-Mt, contrary to that of the pristine clays. The pristine and functionalized materials were investigated by XRD, FTIR, BET, SEM and zeta potential analysis to gain in-depth insight into the structure and surface morphology. The results showed that BAL was successful grafted on montmorillonite and vermiculite surface, providing plentiful adsorption sites as chelating ligands. The mechanisms of Hg(II) adsorption on these samples could be further explained as ion exchange and electrostatic attraction for Vm and Mt, and formation of complexes for BAL-Vm and BAL-Mt.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 18
·1514
·
IF 4.4
Feifei Wang,Lei Ge,Lin Li,Tianyue Zhao,Tifeng Jiao
The LB films prepared through the Langmuir–Blodgett (LB) technique are of significant importance for the fabrication of functional films such as optoelectronic materials and sensors. In this study, 9,9-bis (4-(2-hydroxy-ethoxy) phenyl) fluorene (BPEF) and 9,9-bis [3-phenyl-4-(β-hydroxy-ethoxy) phenyl] fluorene (BBPEF) were combined with saffron T (ST), methylene blue (MB) and Rhodamine B (RhB) dyes by LB technique to prepare ordered composite films. The nanostructures and morphologies of the composite films were analyzed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). It was found that the films exhibited distinct aggregation morphologies. The UV-VIS absorption spectra showed that the concentration of dye molecules had a significant effect on the spectral characteristics. The contact Angle test shows that the prepared composite films are hydrophobic. The photovoltaic conversion performance of LB composite films was studied by transient photocurrent response experiments. It was found that BPEF/dye and BBPEF/dye composite films exhibited significant responses in photocurrent. In particular, BPEF/RhB and BBPEF/RhB composite films demonstrated excellent photoresponsive performance. This study used LB technology in combination with BPEF and BBPEF to demonstrate enhanced photocurrent and stable performance of LB film, which provided ideas for expanding the application range of materials.
研究领域:
材料科学
·
光电材料
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DOI
PubMed
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 7
·4458-4460
·
IF 1.134
Kim Jong Kyu,Yeo Wooseok,Joo Jin Chul
Among the various radioactive materials, Cesium is a major source of radioactive contamination and known to be the most dangerous radioactive material, can cause enormous damage to the ecosystem environment when released into the environment. Prussian Blue (PB) has been used as an adsorbent
to effectively remove cesium, however it has the problem of being difficult to separate in water. In this study, carbonyl iron (CI) which is known as ferromagnetic synthesized with precursor of PB (FeCl3 and potassium ferricyanide) to solve the problem of PB particles. Adsorption
isotherm experiments were also conducted to evaluate the cesium removal ability of the manufactured novel composites. The results obtained in the present study indicate that the novel composite has a cesium removal rate of 99.88% and a distribution coefficient value of 124,900 mL/g. Adsorption
behavior follows Langmuir isotherms and the maximum adsorption amount is (qm
) 79.3 mg/g. In conclusion, Nano-sized Prussian blue with carbonyl Iron prepared through this study has excellent cesium removal capacity, and it can be completely separated from water when used directly
in the cesium treatment field.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
·
2017
·Vol. 43
·期 11
·5809-5817
·
IF 0.865
Li Jie,Wang Shixing,Peng Jinhui,Lin Guo,Hu Tu,Zhang Libo
A new adsorbent (AC–BP–V) was synthesized by activated carbon, which was used to remove anionic amaranth from aqueous solutions. The adsorption capability, adsorption isotherm and kinetics of the AC–BP–V were studied. X-ray photoelectron spectroscopy (XPS) and zeta potential were employed to characterize the adsorbent. Experimental results indicated that AC–BP–V adsorbent exhibited high-selectivity adsorption and efficiency for anionic dyes. Adsorption behavior of the modified activated carbon from aqueous solution was investigated by varying the parameters such as pH, contact time and amaranth concentration, and the optimum adsorption pH was 1. The equilibrium data fitted well with the Langmuir isotherm, and the obtained kinetic data obeyed the pseudo-second-order kinetic model. The maximum adsorption capacity was 216.92 mg/g. The new adsorbent (AC–BP–V) has obvious selectivity to anionic dyes. The results indicated that electrostatic interaction was the main mechanism for the adsorption of anionic amaranth.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2016
·Vol. 310
·期 2
·611-622
·
IF 0.983
Wu Liping,Lin Xiaoyan,Du Xinchen,Luo Xuegang
The carboxymethyl cellulose microsphere loaded with Al(III) (CMC-Al) has been explored for removal of uranium(VI) from U-containing water. Various factors, including pH, adsorbent dosage and uranium(VI) concentration, were tested. Langmuir and Freundlich isotherms were applied to the adsorption data. The thermodynamic parameters such as Δ H °, Δ S ° and Δ G ° were also evaluated. The mechanism of modification and adsorption on CMC-Al were analyzed by SEM, EDX and XPS. Results show Al (III) was loaded on CMC through ion exchange of sodium ion of CMC. The coordination reaction happened during the adsorption process between CMC-Al and uranium(VI).
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
Arabian Journal of Chemistry
·
2013
·
IF 2.266
Tiantian Sheng,Shams Ali Baig,Yunjun Hu,Xiaoqin Xue,Xinhua Xu
The adsorptive removal of As(V) from aqueous solutions using iron-coated honeycomb briquette cinder (Fe-HBC) is presented. Low cost mechanical granulation process was integrated with surface amendment technology to prepare iron-oxide modified granular adsorbent for clean water production. Detailed characterizations were performed using FTIR, XRD, EDS and SEM techniques. Operating parameters including initial As(V) concentration, pH, contact time, adsorbent dose, iron leaching and the effects of competing ions on As(V) removal were evaluated. Results demonstrated that high amount of arsenate (961.5 μg g −1 ) was adsorbed at pH 7.5 in 14 h contact time. Langmuir, Freundlich and Temkin isotherm models were used to analyze the adsorption data, whereas Langmuir model was found to best represent the data with a correlation co-efficient ( R 2 = 0.999). Thus, As(V) sorption on Fe-HBC surface suggested monolayer adsorption and indicated surface homogeneity. Moreover, the dimensionless parameter ( R L ) value calculated to be about 0.118 that reiterated the process is favorable and spontaneous. The influences of competing ions on As(V) removal decreased in the following order:
PO 4 3 − > HCO 3 − > F − > Cl − . The profound inhibition effects of
PO 4 3 − revealed a high affinity toward iron(oxy) hydroxide. Life-cycle assessment confirmed that spent HBC is non-hazardous and can be used as a promising sorbent for arsenic removal.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 12
·1923
·
IF 4.329
Mingjun Cui,Yue Yu,Yuxuan Zheng
In present study, novel nitrogen doped carbon dots (NCDs) are synthesized using a green material—dopamine—as a precursor and studied as corrosion inhibitors for Q235 carbon steel in 1 M HCl solution. According to the electrochemical results, it is found that NCDs acting as a mixed-type corrosion inhibitor can effectively retard the acid corrosion of carbon steel, and their inhibition efficiency increases with the concentration increasing from 50 to 400 ppm. The highest inhibition efficiency is 96.1% in the presence of 400 ppm NCDs at room temperature. Additionally, the adsorption of NCDs obeys the Langmuir adsorption isotherm. In addition, weight loss results show that the inhibition efficiency in the presence of 400 ppm NCDs increases with prolonged exposure time and rising temperature (298–328 K), owing to the strong adsorption of NCDs on the steel surface, and the η value is 92.2% at 60 h of immersion and 86.2%, 89.1%, 90.6% and 92.9% at 298, 308, 318 and 328 K, respectively. Surface analysis by scanning electron microscope (SEM), laser scanning confocal microscope (LSCM) and X-ray photoelectron spectroscopy (XPS) further proves the formation of a protective NCD film on the steel surface.Keywords:corrosion inhibition;Q235 carbon steel;NCDs;electrochemical techniques;Langmuir adsorption
研究领域:
材料科学
·
电化学
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DOI
PubMed
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2018
·Vol. 18
·期 1
·407-413
·
IF 1.354
Zhu Yuanna,Wang Jianrong,Wang Yingzi,Song Xueling,Xu Yanan,Yang Ping
Fe3O4@AlOOH adsorbent with high efficient adsorption capacity was successfully synthesized by controlling the hydrolysis rate for aluminum isopropoxide (AIP) and introducing inductive agent thioglycolic acid (TGA). Al(OH)3-TGA clusters played a key role
in the formation of Fe3O4@AlOOH adsorbent with lamellar structure. Morphology characterization revealed that magnetic Fe3O4 nanoparticles were uniformly deposited on the surface of AlOOH. The lamellar structure of AlOOH and the strong magnetic intensity
of Fe3O4 were helpful for its rapid separation from solution under external magnetic field. Hence, the sample could be regenerated easily and reused in the later adsorption–desorption cycles. The as-prepared sample exhibited ultrafast adsorption rate and high adsorption
capacity in the removal of Congo Red (CR) from aqueous solution. The maximum adsorption capacity of Fe3O4@AlOOH towards CR was 280.90 mg/g and CR was completely removed from the aqueous solution within 60 seconds. The adsorption process was well described by the Langmuir
isotherm model. Electrostatic adsorption was considered as the main adsorption mechanism. Moreover, Fe3O4@AlOOH sample tended to adsorb CR more effectively in the neutral and acidic solution.
研究领域:
材料科学
·
环境科学
·
化学工程
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DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Pan Liu,Guixia Fan,Jingtao Wang,Guoli Zhou,Yijun Cao,Xiangke Han,Xueqin Xu
Biomimetic mineralization is one of the effective methods for synthesizing functional materials with specific shape structures, and the raw materials required for the process are cheap and readily available. Here we designed a novel method, in which graphene oxide assisted biomimetic mineralization to prepare a biomimetic-coral structural material with the characteristics of sensing and capturing metal ions . The coral-like structure featured tight, fine and uniform channels for efficient provided plentiful adsorption sites while exposing various functional groups such as -OH, -COOH. The maximum theoretical adsorption capacity of the material was calculated by the Langmuir model. About 88.3% of Cu(II) was adsorbed rapidly within a contact time of 30 min, and the maximum adsorption capacity was 198.8 mg g −1 at pH = 6 and T = 298 K. The adsorption mechanism was proved that chelation was the dominant governing mechanism for copper ions adsorption on the material.
研究领域:
材料科学
·
环境科学
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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）