The Experts below are selected from a list of 1596 Experts worldwide ranked by ideXlab platform
Aiqin Wang - One of the best experts on this subject based on the ideXlab platform.
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polydopamine clay functionalized calotropis gigantea fiber a recyclable oil absorbing material with large lumens
Journal of Natural Fibers, 2019Co-Authors: Lixin Tu, Weilong Xiao, Wenzhen Duan, Ningfen Wang, Aiqin Wang, Yian ZhengAbstract:ABSTRACTA facile route was used for improving the oil-absorbing performance of Calotropis gigantea fiber (CGF) via a convenient oxidative polymerization of dopamine in the presence of Attapulgite (...
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fabrication of Attapulgite carbon composites from spent bleaching earth for the efficient adsorption of methylene blue
RSC Advances, 2015Co-Authors: Jie Tang, Li Zong, Maosong Zheng, Aiqin WangAbstract:In this work, one-dimensional Attapulgite/carbon composites were prepared by a one-step carbonization process using the residual organic matter of spent bleaching earth as a low-cost available carbon precursor. The obtained composites were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis to confirm the presence of carbonaceous species. The Attapulgite/carbon composites can be used as adsorbents for the removal of methylene blue, with a maximum adsorption capacity of 132.72 mg g−1, and the process parameters affecting the adsorption behavior for methylene blue, such as the pH of the solution, calcination temperature and contact time, were also analyzed through batch adsorption processes. It was revealed that Attapulgite/carbon composites could be employed as candidates for the removal of cationic dyes.
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one pot fabrication of multifunctional superparamagnetic Attapulgite fe3o4 polyaniline nanocomposites served as an adsorbent and catalyst support
Journal of Materials Chemistry, 2015Co-Authors: Aiqin WangAbstract:Multifunctional superparamagnetic Attapulgite/Fe3O4/polyaniline (APT/Fe3O4/PANI) nanocomposites have been fabricated by a one-pot process using Fe(III) as the oxidant for aniline and the precursor of Fe3O4 in the presence of Attapulgite. The introduction of Attapulgite can effectively induce the uniform encapsulation of polyaniline and Fe3O4 nanoparticles on the surface of Attapulgite to form the Anthurium andraeanum-like structure, preventing the formation of free aggregates of polyaniline and Fe3O4 nanoparticles. The morphologies and the magnetic properties of the as-prepared nanocomposites can be facilely controlled by adjusting the molar ratio of aniline to Fe(III). The APT/Fe3O4/PANI nanocomposites can be used as an adsorbent for the removal of dyes and the enrichment of Au(III) from the solution. In addition, the adsorbed Au(III) could be reduced to elemental gold to obtain APT/Fe3O4/PANI supported Au nanocomposites due to the good redox activities of PANI, which exhibited excellent catalytic activity toward the catalytic reduction of 4-nitrophenol in the presence of NaBH4.
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Attapulgite bentonite interactions for methylene blue adsorption characteristics from aqueous solution
Chemical Engineering Journal, 2014Co-Authors: Yi Liu, Yuru Kang, Aiqin WangAbstract:Attapulgite/bentonite composite adsorbents have been prepared via high-pressure homogenization technique. It was aimed to investigate the synergistic effect of one-dimensional Attapulgite and two-dimensional bentonite on the adsorption property for methylene blue (MB) from aqueous solution in this paper. The process parameters affecting adsorption behaviors such as bentonite content, pH of MB solution, contact time and initial concentration were systematically investigated. The results showed that the adsorption capacity of the adsorbents increased with the increase in the content of bentonite while the adsorption rate decreased due to the decrease in the content of Attapulgite. The adsorption process could be well described by pseudo-second-order kinetics and Langmuir isotherm model rather than Freundlich and Temkin isotherm models. The MB loaded adsorbents were not easily desorbed with diluted HCl or NaOH solution, and thus can be employed as candidates for organic–inorganic pigments.
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a novel n succinylchitosan graft polyacrylamide Attapulgite composite hydrogel prepared through inverse suspension polymerization
Macromolecular Materials and Engineering, 2007Co-Authors: Junping Zhang, Aiqin WangAbstract:A novel N-succinylchitosan-graft-polyacrylamide/Attapulgite composite hydrogel was prepared by using N-succinylchitosan, acrylamide and Attapulgite through inverse suspension polymerization. The result from FTIR spectra showed that -OH of Attapulgite, -OH and -NHCO of N-succinylchitosan participated in graft polymerization with acrylamide. The introduced Attapulgite could enhance thermal stability of the hydrogel. Scanning electron microscopy observation indicates that the composite hydrogel has a microporous surface. The volume ratio of heptane to water, weight ratio of acrylamide to N-succinylchitosan and Attapulgite content have great influence on swelling ability of the composite hydrogel. The composite hydrogel shows higher swelling rate and pH-sensitivity compared to that of without Attapulgite.
Junping Zhang - One of the best experts on this subject based on the ideXlab platform.
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a novel n succinylchitosan graft polyacrylamide Attapulgite composite hydrogel prepared through inverse suspension polymerization
Macromolecular Materials and Engineering, 2007Co-Authors: Junping Zhang, Aiqin WangAbstract:A novel N-succinylchitosan-graft-polyacrylamide/Attapulgite composite hydrogel was prepared by using N-succinylchitosan, acrylamide and Attapulgite through inverse suspension polymerization. The result from FTIR spectra showed that -OH of Attapulgite, -OH and -NHCO of N-succinylchitosan participated in graft polymerization with acrylamide. The introduced Attapulgite could enhance thermal stability of the hydrogel. Scanning electron microscopy observation indicates that the composite hydrogel has a microporous surface. The volume ratio of heptane to water, weight ratio of acrylamide to N-succinylchitosan and Attapulgite content have great influence on swelling ability of the composite hydrogel. The composite hydrogel shows higher swelling rate and pH-sensitivity compared to that of without Attapulgite.
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synthesis and characterization of chitosan g poly acrylic acid Attapulgite superabsorbent composites
Carbohydrate Polymers, 2007Co-Authors: Junping Zhang, Qin Wang, Aiqin WangAbstract:A novel chitosan-g-poly(acrylic acid)/Attapulgite superabsorbent composite with water absorbency of 159.6 g g � 1 in distilled water and 42.3 g g � 1 in 0.9 wt% NaCl solution was prepared by graft polymerization with chitosan, acrylic acid and Attapulgite in aqueous solution, using N,N 0 -methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. Factors influencing water absorbency of the superabsorbent composite were investigated, such as average molecular weight of chitosan, weight ratio of acrylic acid to chitosan, dewatering method, the amount of crosslinker and Attapulgite. The result from FTIR spectra showed that –OH of Attapulgite, –OH, –NHCO and –NH2 of chitosan participated in graft polymerization with acrylic acid. The introduced Attapulgite enhanced thermal stability of the chitosan-g-poly(acrylic acid) superabsorbent and formed a loose and more porous surface. Introducing a small amount of Attapulgite also enhanced water absorbency of the chitosan-g-poly(acrylic acid) superabsorbent. � 2006 Elsevier Ltd. All rights reserved.
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study on superabsorbent composite vi preparation characterization and swelling behaviors of starch phosphate graft acrylamide Attapulgite superabsorbent composite
Carbohydrate Polymers, 2006Co-Authors: Junping Zhang, Aiqin WangAbstract:Abstract A novel starch phosphate-graft-acrylamide/Attapulgite superabsorbent composite was prepared by graft-copolymerization among starch phosphate, acrylamide, and Attapulgite in aqueous solution. In this paper, factors influencing water absorbency of the superabsorbent composite such as the molar ratio of NaOH to AM and the amount of starch phosphate and Attapulgite were investigated. The superabsorbent composite acquired the highest equilibrium water absorbency of 1268 g g −1 when the molar ratio of COO − , COOH, and CONH 2 is 10:3:11, the weight ratio of AM to starch phosphate is 5:1, and 10 wt% Attapulgite was incorporated. The graft-copolymerization reaction mechanism, morphology, and thermal stability of the composites were also investigated by FTIR, scanning electron microscopy, and thermo-gravimetric analysis, respectively. The introduced starch phosphate and Attapulgite endowed the composite a higher thermal stability. In addition, swelling rate, and equilibrium water absorbency in various saline solutions were investigated to study the effect of starch phosphate and Attapulgite on swelling behaviors of the composite. The results indicate that the phosphorylation of starch and the introduction of Attapulgite could greatly improve equilibrium water absorbency, swelling rate and salt-resistant properties of corresponding superabsorbent composite.
Salem Alkatheiri - One of the best experts on this subject based on the ideXlab platform.
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sand Attapulgite clay mixtures as a landfill liner
Geotechnical and Geological Engineering, 2006Co-Authors: Amer Alrawas, Yahia E A Mohamedzein, Abdulaziz S Alshabibi, Salem AlkatheiriAbstract:This paper investigates the potential use of sand–Attapulgite (palygorskite) mixtures as a landfill liner. The sand and Attapulgite clay used in this study were brought from Wahiba (eastern Oman) and Al-Shuwamiyah (southern Oman), respectively. Initially the basic properties of the sand and clay were determined. Then the Attapulgite clay was added to the sand at 5, 10, 20 and 30% by dry weight of the sand. The sand–Attapulgite clay mixtures were subjected to mineralogical, chemical, microfabric and geotechnical analyses. The X-ray diffraction (XRD) qualitative analysis showed that Attapulgite is the major clay mineral. The chemical compounds, exchangeable cations and cation exchange capacity (CEC) for the␣samples were determined. The CEC for the sand–clay mixtures is low but increases with the increase in clay content. The scanning electron microscope (SEM) examination showed that the addition of clay developed coating between and around the sand grains which results in filling the voids and reducing the hydraulic conductivity of the sand–clay mixtures. The hydraulic conductivity values for the pure clay and sand + 30% clay mixture prepared at 2% above optimum water content are slightly higher than hydraulic conductivity requirements for landfill liners but can be acceptable. The geotechnical study which included grain size distribution, Atterberg limits, specific gravity, compaction, hydraulic conductivity and shear strength tests showed that the sand+30% clay mixture prepared at 2% above optimum water content can be considered to satisfy the requirements for landfill liners. For all sand–clay mixtures no swelling was recorded and the addition of clay to the sand improved the shear strength.
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sand Attapulgite clay mixtures as a landfill liner
Geotechnical and Geological Engineering, 2006Co-Authors: Amer Alrawas, Yahia E A Mohamedzein, Abdulaziz S Alshabibi, Salem AlkatheiriAbstract:This paper investigates the potential use of sand–Attapulgite (palygorskite) mixtures as a landfill liner. The sand and Attapulgite clay used in this study were brought from Wahiba (eastern Oman) and Al-Shuwamiyah (southern Oman), respectively. Initially the basic properties of the sand and clay were determined. Then the Attapulgite clay was added to the sand at 5, 10, 20 and 30% by dry weight of the sand. The sand–Attapulgite clay mixtures were subjected to mineralogical, chemical, microfabric and geotechnical analyses. The X-ray diffraction (XRD) qualitative analysis showed that Attapulgite is the major clay mineral. The chemical compounds, exchangeable cations and cation exchange capacity (CEC) for the␣samples were determined. The CEC for the sand–clay mixtures is low but increases with the increase in clay content. The scanning electron microscope (SEM) examination showed that the addition of clay developed coating between and around the sand grains which results in filling the voids and reducing the hydraulic conductivity of the sand–clay mixtures. The hydraulic conductivity values for the pure clay and sand + 30% clay mixture prepared at 2% above optimum water content are slightly higher than hydraulic conductivity requirements for landfill liners but can be acceptable. The geotechnical study which included grain size distribution, Atterberg limits, specific gravity, compaction, hydraulic conductivity and shear strength tests showed that the sand+30% clay mixture prepared at 2% above optimum water content can be considered to satisfy the requirements for landfill liners. For all sand–clay mixtures no swelling was recorded and the addition of clay to the sand improved the shear strength.
Yukui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Attapulgite nanoparticles modified monolithic column for hydrophilic in tube solid phase microextraction of cyromazine and melamine
Analytical Chemistry, 2016Co-Authors: Tingting Wang, Yihui Chen, Qian Qian, Zhenfeng Jin, Lihua Zhang, Yukui ZhangAbstract:In current study, a novel monolithic capillary column with embedded Attapulgite nanoparticles has been developed and exploited as a stationary phase in hydrophilic in-tube solid phase microextraction (SPME) of cyromazine and melamine. The fibrillar Attapulgite nanoparticles were embedded in the poly(1-vinyl-3-(butyl-4-sulfonate) imidazolium-co-acrylamide-co-N,N′-methylenebis(acrylamide)) (poly(VBSIm-AM-MBA)) monolith via in situ polymerization. The Attapulgite/polymerization ratio of the monolith was finely optimized. Primary factors of in-tube SPME including sample solvent, elution solvent, sample loading volume, elution volume, sample loading flow rate, and elution flow rate were thoroughly evaluated. Under optimal conditions, the limits of detection (LODs) were found to be 21.1 and 0.3 ng mL–1 for cyromazine and melamine in the milk formula sample, respectively. Also, the recoveries of cyromazine and melamine spiked in the sample ranged from 94.5% to 109.9% with RSDs less than 7.6%.
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Attapulgite Nanoparticles-Modified Monolithic Column for Hydrophilic In-Tube Solid-Phase Microextraction of Cyromazine and Melamine
2016Co-Authors: Tingting Wang, Yihui Chen, Qian Qian, Zhenfeng Jin, Lihua Zhang, Yukui ZhangAbstract:In current study, a novel monolithic capillary column with embedded Attapulgite nanoparticles has been developed and exploited as a stationary phase in hydrophilic in-tube solid phase microextraction (SPME) of cyromazine and melamine. The fibrillar Attapulgite nanoparticles were embedded in the poly(1-vinyl-3-(butyl-4-sulfonate) imidazolium-co-acrylamide-co-N,N′-methylenebis(acrylamide)) (poly(VBSIm-AM-MBA)) monolith via in situ polymerization. The Attapulgite/polymerization ratio of the monolith was finely optimized. Primary factors of in-tube SPME including sample solvent, elution solvent, sample loading volume, elution volume, sample loading flow rate, and elution flow rate were thoroughly evaluated. Under optimal conditions, the limits of detection (LODs) were found to be 21.1 and 0.3 ng mL–1 for cyromazine and melamine in the milk formula sample, respectively. Also, the recoveries of cyromazine and melamine spiked in the sample ranged from 94.5% to 109.9% with RSDs less than 7.6%
Wenxuan Ding - One of the best experts on this subject based on the ideXlab platform.
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tribological properties of Attapulgite la2o3 nanocomposite as lubricant additive for a steel steel contact
RSC Advances, 2018Co-Authors: Kaihe Zhou, Jibin Pu, Yunhui Fang, Wenxuan DingAbstract:Attapulgite is a layered silicate with good friction-reduction and self-repairing properties. In order to further improve its tribological properties, the present work mainly focuses on the preparation of Attapulgite/La2O3 nanocomposite and study on its tribological behaviors. The tribological properties of mineral lubricating oil (150SN) containing Attapulgite/La2O3 nanocomposite were investigated through an Optimal SRV-IV oscillating friction and wear tester. The rubbing surfaces and generated tribofilms were characterized by SEM, EDS, XPS and nanoindentation. Results indicated that the friction-reducing ability and antiwear property of the oil were both remarkably improved by Attapulgite/La2O3 nanocomposite. A tribofilm mainly composed of Fe, Fe3C, FeO, Fe2O3, FeOOH, SiO, SiO2 and organic compound was formed on the rubbing surface under the lubrication of oil with Attapulgite/La2O3 nanocomposite. The tribofilm possess excellent self-lubricating ability and mechanical properties, which is responsible for the reduction of friction and wear.