JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2025
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IF 1.9
JinSong Ri,Yimin Xie,Mingliang Wang,Chunlin Guo,Dengao Chang,CholJin Sin,SongChol Ri
To remove ammonia nitrogen from synthetic wastewater, carbon felt (CF) was modified with potassium chlorate, sulfuric acid, sodium persulfate, and sodium hydroxide. The specific surface area and the pore volume of CF after modification individually increased 1.27 and 1.06 times more than pristine CF, resulted in the improvement of ammonia nitrogen adsorption efficiency superior to pristine CF. Under the optimal conditions—specifically, a dosage of 25 g/L, a synthetic wastewater pH of 5.5, an adsorption time of 240 min, and an initial ammonia nitrogen concentration of 5 mg/L at 25 °C—, the removal efficiency reached 72.8±3.4%, with an adsorption capacity of 0.153±0.013 mg/g. As the initial concentration of ammonia nitrogen increased from 5 mg/L to 200 mg/L, the removal efficiency correspondingly decreased from 72.8±3.4% to 12.5±0.7%, while the adsorption capacity increased from 0.153±0.013 mg/g to 1.052±0.043 mg/g. After seven regeneration cycles at a voltage of 2 V and a charging time of 1 min, the recovery rate of modified CF was 88.1±1.2%, with an ammonia nitrogen removal efficiency of 65.9±1.6%. The adsorption process was described by the Langmuir isotherm and pseudo-second-order kinetic models, indicating that it is characterized by homogeneous monolayer adsorption primarily driven by chemisorption. The ammonia nitrogen adsorption process on modified CF is exothermic and is characterized by a gradual decrease in adsorption rate.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2017
·
IF 0
Qiu Hong Mu,Dan Peng,Feng Wang,Wei Ju,Fang Zhi Zhang
Octavinyl polyhedral oligomeric silsesquioxane (POSS) were used to hybrid with polysiloxane matrix by two methods, physical blending (PB) and chemical modification (CM). Mechanical, thermal and morphological properties of composites were studied by changing the percentage of POSS and investigated by thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and wide angle X-ray diffraction (XRD) measurements. The results show that the hybrid composites have better mechanical and thermal property than the parent polymer matrix, and CM-prepared composites show better reinforcing role compared with PB-prepared samples. The CM method was hydrosilylation reaction of octavinyl-POSS with hydrogen terminated poly(methylphenylsiloxane) (HPMPS) and the FTIR and NMR results of modified POSS revealed that hydrosilylation reaction took place successfully but was not complete. The modified POSS consisting partial segments of HPMPS attached to the central POSS core showed better distribution in matrix than PB-prepared POSS hybrid composites.
研究领域:
材料科学
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高分子化学
✓ 已验证
DOI
Lubricants
·
2023
·Vol. 11
·期 5
·198
·
IF 3.5
Yumeng Wang,Ning Shi,Min Liu,Sheng Han,Jincan Yan
In this work, a chemical modification method was used to prepare silicone grease with high thermal conductivity. We report two preparation methods for thermal conductive fillers, which are hydroxylated boron nitride-grafted carboxylic silicone oil (h-BN-OH@CS) and amino boron nitride-grafted carboxylic silicone oil (h-BN-NH2@CS). When h-BN-OH@CS and h-BN-NH2@CS were filled with 30 wt% in the base grease, the thermal conductivity was 1.324 W m−1K−1and 0.982 W m−1K−1, which is 6.04 and 4.48 times that of the base grease (0.219 W m−1K−1), respectively. The interfacial thermal resistance is reduced from 11.699 °C W−1to 1.889 °C W−1and 2.514 °C W−1, respectively. Inorganic filler h-BN and organic filler carboxylic silicone oil were chemically grafted to improve the compatibility between h-BN and the base grease. The covalent bond between functionalized h-BN and carboxylic silicone oil is stronger than the van der Waals force, which can reduce the viscosity of the silicone grease.Keywords:silicone grease;boron nitride;thermal conductivity;interfacial thermal resistance;chemical modification
研究领域:
材料科学
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热管理技术
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产品关联
DOI
高影响因子
Separations
·
2023
·Vol. 10
·期 6
·358
·
IF 2.6
Xiangfen Cui,Juan Wang,Qun Zhao,Chen Li,Jianhong Huang,Xuewei Hu,Jie Li,Mantao Li
Biochar adsorption has emerged as a favorable and environmentally friendly approach for removing metals such as chromium (Cr) from wastewater. However, the use of pristine biochar (PBC) is limited due to its finite adsorptive capacity, selectivity, and potential for secondary pollution. In this study, a novel bifunctionalized magnetic biochar (BMBC) was fabricated by incorporating cystamine as a ligand and glutaraldehyde as a crosslinker into alkali-treated magnetic biochar (MBC). This chemical modification introduced numerous amino groups and disulfide bonds onto the surfaces of BMBC. The biochar adsorbents’ surface morphologies, crystal structures, and texture properties were characterized using SEM, XRD, and N2adsorption-desorption techniques. The specific surface area was determined using the BET method. Furthermore, the surface functional groups and elemental compositions before and after adsorption were analyzed using FTIR and XPS, respectively. The results demonstrated higher Cr(VI) removal efficacy of BMBC (100%) than MBC (72.37%) and PBC (61.42%). Optimal conditions for Cr(VI) removal were observed at a solution pH of 2, a temperature of 50 °C, a reaction time of around 1440 min, and an initial adsorbate concentration of 300 mg/L. The sorption process followed a chemical mechanism and was controlled by monolayer adsorption, with a maximum adsorption capacity of 66.10 mg/g at 50 °C and a pH of 2, as indicated by the larger fitting values of the pseudo–second-order and Langmuir models. The positive ∆Hoand ∆Sovalues and negative ∆G0 values suggested a spontaneous and endothermic Cr(VI) adsorption process with high randomness at the solid/liquid interface. The removal of Cr(VI) was attributed to the reduction of Cr(VI) into Cr(III) facilitated by the introduced amino acids, sulfur, and Fe(II), electrostatic interaction between Cr(VI) in the solution and positive charges on the adsorbent surface, and complexation with functional groups. The presence of co-existing cations such as Cu(II), Cd(II), Mn(II), and K(I) had little effect on Cr(VI) removal efficiency. At the same time, the co-existence of anions of Cl−, NO3−, SO42−, and HPO42−resulted in a 7.58% decrease in the Cr(VI) removal rate. After five consecutive adsorption/desorption cycles, BMBC maintained a high Cr(VI) removal rate of 61.12%. Overall, this novel BMBC derived from rice straw shows great promise as a biosorbent for treating Cr(VI) in wastewater.Keywords:magnetic biochar;bifunctionalization;chemical modification;hexavalent chromium;adsorption
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 17
·4329
·
IF 3.1
Junpeng Ren,Shijiang Zhang,Yu Wang,Hengxiu Yang
The abundant pore structure and carbon composition of sphagnum peat moss render it a bio-based adsorbent for efficient methylene blue removal from wastewater. By utilizing sphagnum moss sourced from Guizhou, China, as raw material, a cost-effective and highly efficient bio-based adsorbent material was prepared through chemical modification. The structure and performance of the modified sphagnum moss were characterized using SEM, EDS, FTIR, and TGA techniques. Batch adsorption experiments explored the effects of contact time, adsorbent dosage, pH, initial dye concentration, and temperature on adsorption performance. Kinetics, isotherm models, and thermodynamics elucidated the adsorption behavior and mechanism. The modified sphagnum moss exhibited increased surface roughness and uniform surface modification, enhancing active site availability for improved adsorption. Experimental data aligned well with the Freundlich isotherm model and pseudo-second-order kinetic model, indicating efficient adsorption. The study elucidated the adsorption mechanism, laying a foundation for effective methylene blue removal. The utilization of modified sphagnum moss demonstrates significant potential in effectively removing MB from contaminated solutions due to its robust adsorption capability and efficient reusability.
研究领域:
环境科学
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生物材料学
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产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2024
·
IF 8.3
Guijing Chen,Xifan Li,Xin Li,Zhaoyang Song,Baicang Liu
Groundwater in rural areas often contains hardness ions that contribute to scaling on polyamide nanofiltration (NF) membranes used in drinking water treatment. To mitigate this issue, we chemically modified the residual functional groups (acyl chlorides and primary amines) on the surface of a hybridized polyamide layer by reacting them with three small-molecule monomers featuring quaternary ammonium salts: choline chloride, 2,3-dihydroxy- N , N , N -trimethylpropan-1-aminium chloride, and 2,3-epoxypropyltrimethylammonium chloride. This modification created a weakly charged, positive electric field on the underlying negatively charged polyamide surface, enhancing the membrane resistance to scaling and fouling. The chemical grafting altered the membranes' physicochemical properties, including wettability, charge characteristics, surface carboxyl group density, and pore structure. Notably, the modified NF membranes exhibited higher LiCl rejection rates compared to unmodified membranes, demonstrating the effectiveness of electrostatic repulsion against positively charged ions. This finding was supported by changes in zeta potential measurements. Furthermore, the sulfate/chloride separation factor for the modified NF membrane increased from 13.6 to 34.0, indicating improved selectivity while maintaining the desalination mechanism of typical negatively charged membranes. The extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) theory calculations revealed that reducing polar interactions on the NF membrane surface was crucial for enhancing anti-fouling performance. The weakly charged positive electric field actively repelled Ca 2+ from groundwater contacting the membrane surface, while the negatively charged polyamide layer passively inhibited Ca 2+ interaction with the membrane surface through electrostatic repulsion of CO₃ 2− . This dual mechanism resulted in excellent anti-CaCO₃ scaling behavior for the modified NF membranes.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Magnesium and Alloys
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2021
·
IF 10.088
Xiang Liu,Tian C. Zhang,Yuxin Zhang,Jinsong Rao,Shaojun Yuan
Superhydrophobic coating has been widely studied for its great applicational potential, such as for corrosion protection of magnesium alloys while it has been restrained by expensive materials, sophisticated preparation process and infirm rough structures. In this study, the electrochemical method was adopted by using a two-electrode system for rapid hydrophobic modification to obtain superhydrophobic kaolin. By mixing the modified superhydrophobic kaolin with commercial epoxy resin and polydimethylsiloxane glue, a paint can be formed and easily used on various substrates for preparation of superhydrophobic coating via spraying method. The influence factors on wettability of the modified kaolin and the mixing ratio of each component of the coating were explored. Also, the wettability, durability and anticorrosion of the prepared coating were evaluated comprehensively. The coating was able to maintain superhydrophobic after immersed in HCl solution at pH 1, the NaOH solution at pH 14, and 3.5 wt.% NaCl solution for 16, 21, 30 days, respectively. In addition, the coating exhibited 4A grade adhesion, high hydrophobicity after abraded for 200 cycles on a 600-mesh sandpaper with 100 g weight, and 99.86% anticorrosion efficiency after soaked in 3.5 wt.% NaCl solution for 20 days, demonstrating a good robustness and anti-corrosion property. Furthermore, the coating showed good transparency, flexibility and was easy to make in a large scale by the spraying method, which is of great significance to promote the practical application of superhydrophobic coatings and the anticorrosion Mg alloys.
研究领域:
材料科学
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腐蚀与防护
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表面工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Yan Sun,Yue Jing,Zhicheng Wang,Mingjie Huang,Wen-Da Oh,Xiaohui Wu,Tao Zhou
Ubiquitous pyrite (FeS 2 ) in the earth’s crust features strong reducing capacity, presenting a promising alternative for molecular oxygen (O 2 ) activation to facilitate water purification, but the interfacial electron transfer efficiency was remarkably retarded due to the existed passivation layer and limited reactive sites on the surface of pristine pyrite. Herein, we proposed an effective mechanochemical approach to unlock the potential of pyrite for O 2 activation and refractory pollutant degradation. Compared to the inert pristine one, the ball milling-treated pyrite (BMPs) could achieve efficient sulfamethoxazole (SMX) degradation with a rate constant of 0.23 h −1 . By a combination of characterizations, batch experiments, and density function theory (DFT) calculations, a clear panorama delineated the consecutive O 2 adsorption and activation processes was established. Ball milling treatment could import rich sulfur vacancies (SVs) on pyrite, which unshifted the p -band center of adjacent S for improved O 2 adsorption, also narrowed the band gap of BMPs to promote the interfacial electron transfer rate for O 2 activation. Singlet oxygen ( 1 O 2 ) was identified as the dominant reactive species for SMX degradation , such non-radical oxidation feature rendered the system with remarkable activity and environmental robustness. Our work lay a foundation for constructing robust pyrite towards stable and efficient environmental remediation applications.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 2
·306
·
IF 3.164
Tobias Standau,Chunjing Zhao,Svenja Murillo Castellón,Christian Bonten,Volker Altstädt
Polylactide (PLA) is known as one of the most promising biopolymers as it is derived from renewable feedstock and can be biodegraded. During the last two decades, it moved more and more into the focus of scientific research and industrial use. It is even considered as a suitable replacement for standard petroleum-based polymers, such as polystyrene (PS), which can be found in a wide range of applications—amongst others in foams for packaging and insulation applications—but cause strong environmental issues. PLA has comparable mechanical properties to PS. However, the lack of melt strength is often referred to as a drawback for most foaming processes. One way to overcome this issue is the incorporation of chemical modifiers which can induce chain extension, branching, or cross-linking. As such, a wide variety of substances were studied in the literature. This work should give an overview of the most commonly used chemical modifiers and their effects on rheological, thermal, and foaming behavior. Therefore, this review article summarizes the research conducted on neat and chemically modified PLA foamed with the conventional foaming methods (i.e., batch foaming, foam extrusion, foam injection molding, and bead foaming).Keywords:polylactide (PLA);biofoams;chemical modification;foam extrusion;batch foaming;foam injection molding;bead foaming;rheology;crystallization;density reduction
研究领域:
材料科学
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环境科学
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高分子化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2015
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IF 4.642
Ming-Jie Chen,Qing-Shan Shi
The major challenges for directly converting lignocellulosic biomass into available materials in place of synthetic polymer materials are the complex chemical–physical structure and the narrow processing windows of the resources. In the present study, homogeneous chemical modification of sugarcane bagasse with phthalic anhydride was taken to be an improved strategy to meet the challenges. FT-IR and liquid-state NMR spectra confirmed the chemical structure of the sugarcane bagasse phthalates. Sugarcane bagasse phthalates with weight percentage gain higher than 32.9% were readily dissolved in organic solvents, and film materials were prepared by solution casting from the sugarcane bagasse phthalates. Thermogravimetric analysis and differential scanning calorimetry was applied to study the thermal behaviors of the sugarcane bagasse phthalates. Scanning electron microscope, atomic force microscopy and tensile testing were applied to study the morphologies and mechanical properties of the films. The results indicated that sugarcane bagasse was plasticized by homogeneous chemical modification with phthalic anhydride.
研究领域:
材料科学
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生物质能
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2023
·Vol. 44
·期 5
·2766-2777
·
IF 5.2
Min Li,Fei Xing,Tianshu Li,Shaokai Wang,Yizhuo Gu,Wei Zhang,Yanjie Wang,Qinghui Li
The interface properties between surface grown carbon nanotubes carbon fiber (CNTs-CF) and epoxy resin were investigated by different modification methods. The X-ray photoelectron spectrometer probations show that the pristine CNTs-CF has very low contents of both oxygen element and active carbon element. Taking the naked carbon fiber (CF) without CNTs grown as a reference, the interfacial shear strength (IFSS) of CNTs-CF/epoxy is only 5.6% higher. After heat treatment, chemical modification and sizing treatments, the surface chemical activity of CNTs-CF is improved considerably. In contrast with the IFSS of standard CF/epoxy, the interfacial strength of chemical-treated CNTs-CF-E1/epoxy is increased to 122.8 MPa by 29.7%. The increasing content of the epoxy active groups at the modified CNTs-CF-E1 surface is conducive to forming covalent bonds between the epoxy resin and the CNTs-CF-E1 surface particularly the activated nanotube surface. The enhancement of CNT/epoxy interface is beneficial to the over whole interface property of the composites. Hence, the compressive and torsion strength of sizing CNTs-CF-E1 bundle combined with epoxy resin are increased by 32.4% and 14.1%, respectively. The SEM images show the failure morphologies of different modification methods, and the enhancement mechanism of multiscale interface is further clarified. Compared with chemical treatment, heat treatment can remove the inert amorphous carbon on the CNTs-CF fiber surface and improve the interface adhesion of CNT/epoxy and CF/epoxy, and surface sizing treatment improves the CF/epoxy interface. The enhancement mechanisms of these modified CNTs-CFs/epoxy should be ascribed to the competition and synergetic effects of the multiscale interfaces, including CNT/CF, CNT/epoxy, and CF/epoxy.
研究领域:
材料科学
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2012
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IF 4.525
Ting Huang,Renguo Lu,Chao Su,Hongna Wang,Zheng Guo,Pei Liu,Zhongyuan Huang,Haiming Chen,Tongsheng Li
Herein, we have developed a rather simple composite fabrication approach to achieving molecular-level dispersion and planar orientation of chemically modified graphene (CMG) in the thermosetting polyimide (PI) matrix as well as realizing strong adhesion at the interfacial regions between reinforcing filler and matrix. The covalent adhesion of CMG to PI matrix and oriented distribution of CMG were carefully confirmed and analyzed by detailed investigations. Combination of covalent bonding and oriented distribution could enlarge the effectiveness of CMG in the matrix. Efficient stress transfer was found at the CMG/PI interfaces. Significant improvements in the mechanical performances, thermal stability, electrical conductivity, and hydrophobic behavior were achieved by addition of only a small amount of CMG. Furthermore, it is noteworthy that the hydrophilic-to-hydrophobic transition and the electrical percolation were observed at only 0.2 wt % CMG in this composite system. This facile methodology is believed to afford broad application potential in graphene-based polymer nanocomposites, especially other types of high-performance thermosetting systems.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）