TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Yuan Qin,Yongfeng Yang,Mingxia Wu,Yi Yang,Gang Yang
To enhance the antiwear properties of halloysite nanotubes (HNTs), composites of C/HNTs, CuO/HNTs, and MoS 2 /HNTs were prepared using hydrothermal method, and their tribological properties were investigated. The results indicated that the wear resistance was ranked as follows during rotational motion: PAO10 oil < CuO/HNTs (9.1%) < MoS 2 /HNTs (34.5%) < HNTs (41.8%) < C/HNTs (56.4%). In reciprocal motion, the antiwear performance was ordered as follows: PAO10 oil < HNTs < MoS 2 /HNTs < CuO/HNTs < C/HNTs. The consistently superior antiwear performance of C/HNTs can be attributed to the synergistic effect of carbon transfer with HNTs, which rapidly generate a homogeneous carbon film embedded in Fe 2 O 3 , Fe 3 O 4 and SiO x . In contrast, MoS 2 and CuO exhibited inhibitory and competitive effects on the film formation of HNTs.
研究领域:
材料科学
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Li Li,Guanzheng Zhuang,Peng Yuan
Sepiolite can form stable hybrid pigments by immobilizing organic dyes in its microporous structure. Previous investigations demonstrated that the micropores and coordinated water might be responsible for the exceptional color and stability of indigo-sepiolite hybrid pigments. This work reveals the roles of coordinated water in forming hybrid pigments by acid modification. Raw sepiolite was modified by nitric acid at different conditions before use. Then a series of indigo-sepiolite pigments were prepared by indigo and acid-modified sepiolite. Their microstructures were characterized and analyzed by X-ray diffraction, Fourier transform infrared, transmission electron microscopy , and N 2 adsorption-desorption. The color properties of hybrid pigments were evaluated by reflectance spectra and CIE color parameters. Investigations into the chemical stability of pigments were conducted using concentrated HNO 3 and dimethyl sulfoxide. In addition, the photostability of pigments exposed to simulated 30-year illumination in a typical museum was studied. Acid modification of sepiolite contributed to a larger specific surface area and pore volume. However, acid modification resulted in worse color properties and stability due to the removal of coordinated water bonded with octahedral Mg 2+ . These findings confirmed that coordinated water molecules were the key to stabilizing indigo-sepiolite hybrid pigments by forming hydrogen bonds .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2015
·
IF 3
Guangyan Tian,Wenbo Wang,Yuru Kang,Aiqin Wang
Palygorskite (PAL) has been recognized as a potential adsorbent for the removal of various dyes from aqueous solution, and so how to enhance its adsorption capability by an efficient approach becomes the subject of great interests. Herein, natural PAL was modified via a simple one-pot hydrothermal process in the presence of sodium sulphide to enhance the adsorption capabilities. The resultant material was characterized by Fourier transform infrared spectroscopy, X-ray diffraction and field-emission scanning electron microscopy, and the adsorption properties were evaluated using methylene blue (MB) as the model dye to explore the synergetic effect of hydrothermal process and sodium sulphide on the structure, physico-chemical features and adsorption properties. It was found that the PAL rod crystal was partially evolved as new silicate with relatively higher adsorption activity. The adsorption capacity for MB evidently enhanced from 129.71 mg/g to 187.56 mg/g after hydrothermal modification, and the adsorption kinetics can be accurately fitted by a pseudo-second-order model. The chemical adsorption is the main driving force for the adsorption process, and the intensified electrostatic and hydrogen-bonding interaction between MB and PAL and the chemical association of –Si–O – groups with MB molecules plays a key role to enhance the adsorption properties.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Minerals
·
2025
·Vol. 15
·期 3
·251
·
IF 2.2
Jiajun Zhang,Guanzheng Zhuang,Jinrong Chen,Wenxiao Fan,Jixing Fan,Zhuhua Kuang,Dong Liu
This study systematically investigates the colloidal stability, rheological properties, and filtration behavior of palygorskite–montmorillonite mixed clays in both freshwater and seawater systems. By varying the mass content and dispersion medium (freshwater/seawater), we analyze the colloidal stability, zeta potential, flow curves, viscosity, shear-thinning behavior, thixotropy, and fluid loss of the dispersions. The results show that palygorskite exhibits good rheological performance in both freshwater and seawater, while montmorillonite performs better in freshwater but suffers a significant decline in seawater. However, palygorskite demonstrates high fluid loss, which is unfavorable for drilling fluid function. Mixed clays can mitigate the limitations of individual clays to some extent, but the specific performance depends on the clay mineral content and dispersion medium. In freshwater, a small amount of montmorillonite improves the viscosity and shear-thinning behavior of the dispersion, with optimal montmorillonite contents of 22% and 38%, respectively. The thixotropy and fluid loss reduction in the mixed clays are positively correlated with montmorillonite content. In seawater, the rheological performance inversely correlates with Mt content due to montmorillonite’s high sensitivity to electrolytes. The addition of Pal enhances the colloidal stability and rheological properties of the mixed clays in seawater. This work provides theoretical insights into the behavior of mixed clays in different media, offering valuable guidance for the design of seawater-based drilling fluids.
研究领域:
地质学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 72
·58107-58115
·
IF 3.84
Wenbo Wang,Zhifang Zhang,Guangyan Tian,Aiqin Wang
The structural evolution of silicate opens a new avenue to cognize its microstructure, intensify its properties and extend its application. Herein, the one-step transformation of palygorskite (PAL) nanorods into smectite nanosheets was successfully achieved under mild hydrothermal condition with no addition of any extra chemicals. The structural evolution of PAL at different reaction stages and the change in physico-chemical characteristics was intensively studied through field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetry (TG) and Fourier transform infrared spectroscopy (FTIR) techniques. The key factors determining the transformation process were clarified. It was found that the moderate mechanical grinding, pH values and the existence of dolomite are essential to realize the transformation, and alkaline condition may facilitate the transformation. The transformation from nanorods to nanosheets is a rebuilding process of crystals, and the c/2 slide of tetrahedrons represents the main transformation mechanism. After the hydrothermal process, the adsorption capability of RPAL for Cu(II) evidently enhanced by 167%, and 99.01% of Cu(II) ions (only 64.9% for raw PAL) can be removed from 20 mg L−1 of Cu(II) solution.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Wenbo Wang,Guangyan Tian,Zhifang Zhang,Aiqin Wang
Silicate materials have been frequently used as stable, low-cost and efficient adsorbents for the removal of dyes and heavy metal ions from aqueous solution. Herein, at the aim of designing new adsorbent with higher adsorption capacity, natural palygorskite (PAL) was modified via a one-step hydrothermal process by introducing sodium silicate and magnesium salts. The effect of Si/Mg dosage ratio on the structure and physico-chemical features of the adsorbent was investigated, and its adsorption capability for Methylene blue (MB) and Cu(II) ions was intensively evaluated. It was found that Si/Mg dosage ratio is the key to control the adsorption properties of the adsorbent. The active magnesium silicate could be formed around PAL at the moderate Si/Mg dosage ratio, and even the undesirable quartz impurities without adsorption activity in the natural PAL minerals may transform as amorphous magnesium silicate with higher adsorption activity in this process. The adsorbent shows greater BET specific surface areas (407.3 m 2 /g), ideal surface charge distribution and superior adsorption capacity to MB and Cu(II) ions, with the maximum adsorption capacity of 527.22 mg/g for MB and 210.64 mg/g for Cu(II) ions at the Si/Mg dosage ratio of 2:1. The MB molecules and Cu(II) ion could be almost completely removed from 100 mg/L of MB solution and 25 mg/L of Cu(II) solution by the adsorbent, respectively, which is far away higher than that of raw PAL. The electrostatic attraction, ion exchange and chemical association of –Si–O − groups contribute to the enhanced adsorption for MB or Cu(II) ions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2022
·
IF 5.122
Li Li,Guanzheng Zhuang,Mengyuan Li,Peng Yuan,Liangliang Deng,Haozhe Guo
Maya blue is a greenish-blue and stable pigment composed of indigo and palygorskite or sepiolite . Previous studies implied that the properties of Maya blue were influenced by different hydroxyl groups in the clay structure, e.g., zeolitic water, coordinated water, and structural hydroxyls. Therefore, an in-depth investigation was planned to analyze the structures and properties of indigo-sepiolite hybrid pigments in this work. Sepiolite materials were heated at 160, 360, 610, and 880 °C to remove zeolitic water, the first coordinated water, the second coordinated water, and structural hydroxyls. A series of Maya blue simulants were prepared by heating the mixture of indigo and sepiolite materials at 180 °C. Reflectance spectroscopy and CIE 1976 color space were employed to characterize color properties and color differences of hybrid pigments. Chemical resistance to concentrated HNO 3 and dimethyl sulfoxide (DMSO), and photostability under visible light were evaluated. Microporous analysis and Fourier transform infrared spectroscopy were applied to study the indigo-sepiolite interaction. Coordinated water was essential for the greenish-blue color and outstanding stability of Maya blue, while zeolitic water and structural hydroxyls did not affect pigments’ properties. Indigo molecules were confirmed to be inserted into sepiolite channels and formed hydrogen bonds with coordinated water at one side. Structural hydroxyls were insignificant for the formation of Maya blue. This work provides a guideline for preparing stable clay-dye hybrid pigments.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Jian-Jun Jiang,Jun-Feng Wang,Ping Yang,Zhi-Min Xu,Tao He,Qiong Gao,Li-Li Wang,Qu-Sheng Li
The application of palygorskite (PAL) for potentially toxic trace elements (Cd 2+ , Ni 2+ , etc.) remediation in polluted soil can substantially reduce the bioavailability and toxicity of these hazard materials. However, the secretion of organic acids and siderophores by microorganisms might result in the re-mobilization of cadmium (Cd) in PAL-bound forms (PAL-Cd). In this study, the interactive effects between Cd stabilized by PAL and mobilized by siderophores from Pseudomonas fluorescens were performed with four flask-shaking experimental treatments, namely, strain with or without an ability of siderophores production respectively associated with or without PAL-Cd. The GC-MS and UHPLC-MS test methods were used to analyze the concentrations of metabolites. Results showed that the Cd mobilized by strain with siderophores production was 22.1% higher than that of strain without the ability of siderophores production ( p < 0.05). The mobilization of Cd in PAL in turn significantly reduced the siderophores production of Pseudomonas fluorescens by 25.1% ( p < 0.05). The numbers of metabolites significantly up-regulated and down-regulated were 9 and 22 in strain groups with PAL-Cd addition compared with the groups without PAL-Cd, respectively. Metabolomics analysis revealed that the mobilized Cd affects the signal transduction pathway and primary metabolic processes, reduces the metabolic capacity of pentose phosphate pathway, glycolysis and tricarboxylic acid cycle pathway. These changes inhibit the ability of strain to biosynthesize amino acids during the mobilization processes, further reducing the capacity of Pseudomonas fluorescens to produce siderophores. This study provides a useful information on how to select soil Cd-stabilizing materials in a targeted manner and how to avoid Cd re-mobilization by siderophores.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Hengdong Ren,Sheng Wang,Wei Lian,Jialin Ma,Yan Zhao,Yin Liu,Ling Bing Kong,Tian shu Zhang,Won-Chun Oh
Palygorskite (Pal) was used as frameworks to disperse Fe 3 O 4 and polyaniline (PANI) nanoparticles for the preparation of coral-like Pal-dispersed Fe 3 O 4 /PANI composites with improved electromagnetic absorption performance. The processing was a combination of hydrothermal synthesis and simple mechanical stirring. With increasing content of Pal, specific surface area of the Pal-dispersed Fe 3 O 4 /PANI composites was increased from 21.14 m 2 /g to 29.69 m 2 /g, while the composites exhibitd fluffy coral-like structure due to the cation exchange mechanism and rich silanol (Si-OH) group of Pal. Since various loss mechanisms and improved impedance matching , the Pal-dispersed Fe 3 O 4 /PANI displayed an optimal reflection loss of −62.45 dB and a broad effective absorption bandwidth of 5.05 GHz. Therefore, this work develops an inexpensive framework to disperse nanoparticles for electromagnetic absorption materials , while new application of Pal is proposed.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2020
·
IF 4.605
Sheng Wang,Hengdong Ren,Wei Lian,Jiangzhe Wang,Yan Zhao,Yin Liu,Tianshu Zhang,Ling Bing Kong
The effect of ball-to-powder weight ratio on the crystal composition, microscopic morphology and pore structure of palygorskite was systematically studied by using the conventional wet ball milling process. The quartz can be effectively separated from palygorskite through low-speed centrifugal treatment in aqueous solutions, while the strength of ball milling has a significant influence on disaggregation degree of the crystal bundles. When the ratio is 1:2, the rod crystal bundles are well dissociated, while preserving the inherent aspect ratio of the nanofibers. After the treatment, the specific surface area, micropore volume and micropore area are increased from 206.87 m 2 /g, 0.0347 cm 3 /g and 76.07 m 2 /g to 255.03 m 2 /g, 0.0502 cm 3 /g and 109.42 m 2 /g, respectively. For the first time, the purified palygorskite was used as a template to prepare palygorskite/Fe 3 O 4 nanocomposite using by hydrothermal method , for microwave absorbing applications. As expected, the introduction of palygorskite can effectively prevent the aggregation of the Fe 3 O 4 magnetic particles. Meanwhile, the specific surface area of the composite is enlarged from 10.29 m 2 /g to 40.73 m 2 /g, as the weight ratio of Fe 3 O 4 and palygorskite is 2:1, thus leading to enriched interface polarizations and hence resulting in a maximum reflection loss (RL) of −40.41 dB at 4.80 GHz, with effective absorption frequency that can be adjusted over 2–18 GHz by controlling thickness of the composite.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2013
·Vol. 38
·期 2
·777-783
·
IF 2.966
Aijuan Xie,Liang Ji,Shiping Luo,Zhiliang Wang,Yiyang Xu,Yong Kong
A nanocomposite of poly(m-phenylenediamine)/palygorskite (PmPD–PG) is facilely synthesized via in situ oxidative polymerization of m-phenylenediamine (mPD) on palygorskite (PG) and its reactive adsorbability to Cr(VI) is examined. PG in the nanocomposite plays important roles in the improvement of adsorptivity of Cr(VI). The pH value of the solution is increased after adsorption, which is quite different from Pb(II) adsorption with aromatic diamine polymers. This unusual removal behavior of Cr(VI) with PmPD–PG is due to the redox reaction between Cr(VI) and amino/imino groups on the PmPD chains.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2015
·
IF 2.002
Guangyan Tian,Wenbo Wang,Yuru Kang,Aiqin Wang
Herein, palygorskite (PAL) was activated via a simple hydrothermal process in the presence of ammonium sulfide, and the effects of activation on the microstructure, physico-chemical feature and adsorption behaviors of PAL were intensively investigated. The hydrothermal process evidently improved the dispersion of PAL crystal bundles, increased surface negative charges and built more active –Si–O − groups served as the new “adsorption sites”. The adsorption property of the activated PAL for Methyl Violet (MV) was systematically investigated by optimizing the adsorption variables, including pH, ionic strength, contact time and initial MV concentration . The activated PAL exhibited a superior adsorption capability to the raw PAL for the removal of MV (from 156.05 to 218.11 mg/g). The kinetics for MV adsorption followed pseudo second-order kinetic models, while the isotherm and thermodynamics results showed that the adsorption pattern well followed the Langmuir model. The structure analysis of PAL before and after adsorption demonstrated that electrostatic interaction and chemical association of –X–O − are the prominent driving forces for the adsorption process.
研究领域:
环境科学
·
材料科学
✓ 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）