MOLECULES
·
2024
·Vol. 29
·期 9
·2121
·
IF 4.2
Ting Liu,Xinle Li,Hao Wang,Mingyang Li,Hua Yang,Yunhui Liao,Wufei Tang,Yong Li,Fang Liu
Organic dyes are widely used in many important areas, but they also bring many issues for water pollution. To address the above issues, a reconstructed kaolinite hybrid compound (γ-AlOOH@A-Kaol) was obtained from raw kaolinite (Kaol) in this work. The product was then characterized by X-ray diffraction (XRD), Fourier-transform infrared (ATR-FTIR), Brunauer-Emmett-Teller (BET), and scanning electron microscopy (SEM), and the absorption properties of γ-AlOOH@A-Kaol for congo red were further studied. The results demonstrated that flower-like γ-AlOOH with nanolamellae were uniformly loaded on the surface of acid-treated Kaol with a porous structure (A-Kaol). In addition, the surface area (36.5 m2/g), pore volume (0.146 cm3/g), and pore size (13.0 nm) of γ-AlOOH@A-Kaol were different from those of A-Kaol (127.4 m2/g, 0.127 cm3/g, and 4.28 nm, respectively) and γ-AlOOH (34.1 m2/g, 0.315 cm3/g, and 21.5 nm, respectively). The unique structure could significantly enhance the sorption capacity for congo red, which could exceed 1000 mg/g. The reasons may be ascribed to the abundant groups of -OH, large specific surface area, and porous structure of γ-AlOOH@A-Kaol. This work provides an efficient route for comprehensive utilization and production of Kaol-based compound materials that could be used in the field of environmental conservation.
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
PubMed
高影响因子
Journal of Cleaner Production
·
2017
·
IF 5.715
Pengfei Sun,Cai Hui,Rashid Azim Khan,Xiaoxiao Guo,Shengmao Yang,Yuhua Zhao
Kaolin has potential in wastewaters treatment due to its advantage of nontoxicity to aquatic flora and fauna. However, its adsorption capacity needs significant improvement, in addition, the re-collection of adsorbents after application can reduce the risk of desorption of pollutants. Therefore, nanoparticle-modified kaolin (NMK) was prepared by coating kaolin with Fe 3 O 4 nanoparticles to enhance the adsorption capacity of kaolin for crystal violet (CV) in this study. Fe 3 O 4 nanoparticles improved the adsorption capacity of kaolin by at least an order of magnitude, with a maximum capacity of 247.68 ± 4.56 mg CV/g NMK with the initial CV concentration of 800 mg/L; additionally, nanoparticles endowed NMK a magnetization of 21.20 emu/g, indicating that NMK has a magnetic re-collection potential. Spectroscopic analysis demonstrates that the epoxy groups in kaolin are likely the link to the nanoparticles, and the aromatic C C and C O groups of NMK could be responsible for CV adsorption. The enhanced adsorption capacity mechanism of NMK is attributed to nanoparticles decreased zeta potential and changed porous surface characteristics of virgin kaolin. The results suggest that some materials can become more effective in environmental applications via modification by nanoparticles.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Yakui Li,Dongshuang Hou,Xiaoyu Ding,Xingjian Kang,Qinfu Liu
Coal-measure kaolinite with different types were selected to explore the influence of raw mineral on the preparation of intercalation compounds and kaolinite nanotubes . Types of coal-measure kaolinite were feldspar-pseudomorph kaolinite (HSS), worm-like kaolinite (XY), brain striatum kaolinite (CBM), mica-pseudomorph kaolinite (CBM) and crypto crystalline kaolinite (HW and HY), respectively. And the average crystal size of coal-measure kaolinite after grinding of HSS, XY, CBM, HW and HY were 2.60 μm, 6.81 μm, 3.28 μm, 0.52 μm and 0.32 μm, respectively. Characterization methods of XRD, FTIR and SEM were utilized to reveal the change in the crystal structure of kaolinite before and after intercalation reactions, the vibrational pattern of the chemical bond and the surface morphology characteristics of raw minerals and kaolinite nanotubes. Results showed that intercalation effects were significantly different among the selected coal-measure kaolinite, and the intercalation rates of intercalation compound of HSS-KD, XY-KD, CBM-KD, HW-KD and HY-KD were 80.71%, 83.33%, 82.99%, 55.13% and 65.23%, respectively. That is to say, Intercalation rates of feldspar-pseudomorph kaolinite, worm-like kaolinite, brain striatum kaolinite and mica-pseudomorph kaolinite were significantly higher than those of crypto crystalline coal-measure kaolinite which were reflected from intercalation compound of coal-measure kaolinite/dimethyl sulfoxide. Furthermore, the intercalation rates of the precursor intercalation compounds affect the intercalation effect of macromolecular intercalation agents and the yield of kaolinite nanotubes. According to the SEM patterns of kaolinite nanotubes, yield of kaolinite nanotube of HSS, XY, CBM, HW and HY were 80%, 88%, 72%, 28% and 35%, respectively. It could be concluded that yield of kaolinite nanotube of coarse crystalline coal-measure kaolinite was higher than that of crypto crystalline coal-measure kaolinite.
研究领域:
矿物学
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材料科学
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产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2020
·
IF 4.217
Chunquan Li,Ningyuan Zhu,Xiongbo Dong,Xiaoyu Zhang,Ting Chen,Shuilin Zheng,Zhiming Sun
Lamellar kaolinite supported monodispersed TiO 2 was prepared through rational design and 0D/2D structural assembly, which showed significantly improved photocatalytic performance towards ciprofloxacin. After systematic evaluation, the pseudo-first-order kinetic constant rate of TiO 2 /kaolinite composite can reach to 0.04549 min −1 , which was 6.90 and 1.81 times higher than that of pure TiO 2 and P25, respectively. The nano-TiO 2 /kaolinite composite photocatalyst also displayed good reusability performance, only a slight decline occurred after four repeated experiments, which is beneficial for the large-scale application of photocatalysts. Various characterizations indicated that enhanced photocatalytic performance can be ascribed to the synergistic effect between natural kaolinite and the well distributed TiO 2 , which enhanced the light absorption ability, assisted the dispersion of pure TiO 2 , resulted in co-catalysis effect, improved the separation facilitation of photo-induced carriers and promoted the stronger adsorption capacity, etc. These merits effectively regulated the carriers’ lifetime and migration velocity of the photogenerated charge carriers. Considering the excellent properties of natural kaolinite (low cost, abundance, stability, etc.), our study provides a promising candidate for effective degradation of trace amounts of pharmaceutical and personal care product (PPCP) or contaminants with potential high-toxic risk.
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
Arabian Journal of Chemistry
·
2020
·
IF 4.762
Zefeng Yu,Weifeng Song,Jiayao Li,Qiuhua Li
In this paper, a metakaolin-based mesoporous geopolymer (GP-CTAB) was used as adsorbent for Cu(II) and Cr(VI) through a novel and simple synthetic route using cetyltrimethylammonium bromide (CTAB) as an organic modifier. The application of GP-CTAB for the simultaneous removal of metal anions and cations in aqueous solution was studied for the first time. The results of X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Brunauer, Emmett and Teller (BET), and Barrett, Joyner, and Halenda (BJH) methods indicate that GP-CTAB is still geopolymer even in the presence of quaternary ammonium salt cations. The material was tested to simultaneously adsorb Cu(II) and Cr(VI) from an aqueous solution. The results show that GP-CTAB can adsorb anions simultaneously without sacrificing the adsorption properties of heavy metal cations, which is superior to conventional geopolymers. The maximum theoretical adsorption capacity of GP-CTAB for Cu(II) and Cr(VI) was 108.2 mg/g and 95.3 mg/g in the binary system, respectively. It was also found that the presence of Cu(II) in the solution promoted the adsorption of Cr(VI). Given this characteristic of GP-CTAB, it has shown great application prospects in the prevention and control of heavy metal pollution.
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 POLYMERS AND THE ENVIRONMENT
·
2024
·
IF 4.7
Liu Yaqing,Cui Yixin,Meng Huibiao,Long Ke,Shao Linjun,Xing Guiying
Palladium plays an important role in modern industry, agriculture and medicine. The direct discharge of palladium results in serious environmental pollution and loses of precious palladium metal. Herein, kaolin/chitosan hybrid nanofibers were successfully prepared to recover Pd 2+ cations from aqueous solution. Chitosan and kaolin mixture was first electrospun into nanofibers with citric acid as the in situ crosslinking agent and poly(ethylene oxide) as the co-spinning polymer. Then, the chitosan molecules in these hybrid nanofibers were in situ crosslinked by critic acid at elevated temperatures to endow these nanofibers with excellent solvent resistance. Their structure characterization was conducted by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and positron annihilation lifetime spectroscopy (PLAS). The adsorption performances of these fibrous adsorbents were carefully investigated and optimized (e.g. kaolin content, temperature, pH of solution and initial Pd 2+ concentration). The adsorption results demonstrated that incorporation of kaolin powders into the nanofibers could enhance the adsorption capacity from 31 mg/g to 64 mg/g. Thermodynamic parameters studies revealed the endothermic and spontaneous natures of the adsorption process of Pd 2+ cations on these hybrid nanofibers. The Pd 2+ adsorption behavior of this fibrous adsorbent fitted well with the second-order kinetic model, suggesting the chemical adsorption behavior of Pd 2+ cations on this fibrous adsorbent. Moreover, this fibrous adsorbent can be easily regenerated and reused at least three times without significant loss of initial adsorption capacities. These results clearly indicate that this fibrous chitosan/kaolin hybrid absorbent holds great potential in the recovery of precious palladium cations from aqueous solution.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 7
·1370
·
IF 4.324
Zhenfeng Lin,Ziwei Pan,Yuhao Zhao,Lin Qian,Jingtao Shen,Kai Xia,Yongfu Guo,Zan Qu
PPy-Fe3O4/Kaolin was prepared with polypyrrole functionalized magnetic Kaolin by a simple, green, and low cost method to improve the agglomeration and low adsorption capacity of Kaolin. PPy-Fe3O4/Kaolin was employed to remove Hg2+and the results were characterized by various methods. Relevant factors, including solution pH, dosage of adsorbent, concentration (C0), and temperature (T), were optimized by Response Surface Methodology (RSM) and Central Composite Designs (CCD). The optimal results show that the importance for adsorption factors is pH >T>C0> dosage, and the optimal adsorption conditions of PPy-Fe3O4/Kaolin are pH = 7.2,T= 315 K,C0= 50 mg/L, dosage of 0.05 g/L, and the capacity is 317.1 mg/g. The adsorption process conforms to the pseudo-second-order and Langmuir models. Dubinin–Radushkevich model shows that adsorption process is spontaneous and endothermic. Moreover, the adsorption of mercury by PPy-Fe3O4/Kaolin was achieved mainly through electrostatic attraction, pore diffusion, and chelation between amino functional groups and Hg2+. PPy-Fe3O4/Kaolin has excellent reproducibility, dispersity, and chemical stability, and it is easy to be separated from solution through an external magnetic field. The experiments show that PPy-Fe3O4/Kaolin is an efficient and economical adsorbent towards mercury.Keywords:magnetic material;polypyrrole;kaolin;response surface methodology;mercury
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
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Junjun Ma,Tao E,Shuyi Yang,Liang Chen,Ying Cheng,Jia Yu,Yun Li
Stabilizing Cr(III) in tannery sludge (TS) via harmless method has always been the goal of environmental pollution treatment. In this study, a simple method to stabilize Cr(III) in TS is proposed via adding kaolin, based on the fact a large amount of organic matter contained in TS. Comprehensive characterizations confirm that kaolin can stabilize Cr(Ⅲ) via its abundant –OH and lamellar structure. Moreover, there are hydrogen bond interactions and ligand exchange-surface complexation between organic matter and kaolin, which is more conducive to form a stable ternary complex with Cr(III), in a state of organic matter-Cr(III)-kaolin. Simultaneously, the BCR sequential extraction experiment shows that the unstable water and acid soluble state of Cr(III) are reduced (from 0.61% to 0.35%), which further indicates that the stabilization of Cr(III) is successful.
研究领域:
环境科学
·
污染治理
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产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2021
·
IF 6.141
Jinmeng Zhu,Jinghan Ding,Peiyao Zhang,Wenqiang Dong,Xicheng Zhao,Mara Camaiti,Xuanhua Li
Due to the excellent compatibility and ageing-resistant performance, nanolime (NL) as a promising inorganic material is applied to consolidate aged sandstones and other arenaceous rocks based cultural heritage, such as wall paintings and stone relics. However, sometimes, NL does not assure a good consolidation strength for cultural relics. The existing researches on enhancing its consolidation strength are costly, time-consuming or still involving organic polymers. Here, utilizing inexpensive kaolin nanosheets as platform, we design and facilely synthesize a new nanolime/kaolin (N-K) nanocomposite by in-situ growth of Ca(OH) 2 nanoparticles on the surface of kaolin nanosheets. The kinetic stability of this nanocomposite is comparable to the NL. Application experiment shows that the consolidation strength of the N-K nanocomposite in the highly porous pterosaur fossil (65%, porosity) is stronger than that of NL. The reason is due to the incorporation of kaolin nanosheets into the CaCO 3 network after carbonation. For the first time, this work reports a new N-K inorganic nanocomposite and will facilitate the development of NL-based inorganic materials for the conservation of cultural heritage.
研究领域:
文物保护
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材料科学
·
古生物学
✓ 已验证
产品关联
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2020
·
IF 5.88
Xianmou Fan,Shaobing Wang,Yan Fang,Peiyuan Li,Weikang Zhou,Zhengchao Wang,Mingfeng Chen,Haiqing Liu
Adhesive hydrogels for wet and dynamic tissues are important for biomedical applications in order to withstand cyclic loading such as in the case of hemorrhaging control on the curved skins and heart tissues. However, the fabrication of hydrogels with strong mechanical properties, high adhesion strength, and hemostatic efficiency remains a big challenge. Inspired by the great adhesive behavior of mussels and Arion subfuscus , novel adhesive and hemostatic polyacrylamide-tannic acid-kaolin (PAAm-TA-KA) hydrogels were reported in this work. The hydrogels displayed high strength and toughness due to their physical and chemical crosslinking structures. The abundant catechol groups on tannic acid endow the hydrogels with strong and durable adhesion strength of up to 500 kPa on porcine skin. When applied onto human skin, the hydrogels could be easily peeled off without leaving any remains and causing any damages. The kaolin nanoparticles incorporated in the PAAm-TA-KA hydrogels not only served as a physical crosslinking agent, but an activator of the blood clotting factor FXII for accelerating the formation of thrombus. The strong tissue adhesion and blood coagulant potential of the PAAm-TA-KA hydrogels imparted them high hemostatic efficiency. The free-standing, adhesive, tough, cytocompatible, and hemostatic hydrogels are highly promising for traumatic bleeding control materials.
研究领域:
生物医学工程
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材料科学
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止血研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2023
·Vol. 11
·期 3
·703
·
IF 3.5
Liang Shen,Jiabao Gong,Yifang Liu,Erle Qiao
The molecular structure of cationic surfactants is closely related to their flotation performance. In this paper, three cationic surfactants with different head group structures were selected as collectors of kaolinite, and the substituent effects were studied by the DFT method. The DFT calculation results showed that increasing the number of substituents in the dodecylamine head group can significantly increase its surface and head group charge. Dodecylamine has the lowest LUMO orbital energy, so dodecylamine has the strongest electron attraction ability and the strongest interaction with kaolinite. Electron density differential showed that there was an area of electron aggregation between the collector and the surface of the kaolinite. The interaction energy of DDA on kaolinite surfaces was greater than that of the other two collectors, indicating that the adsorption of DDA on the surface of kaolinite was more stable. Flotation results showed that higher a kaolinite yield was obtained in the presence of dodecyl dihydroxyethyl methyl ammonium chloride. The calculated results of the solvent-accessible surfaces, the head group charge, and the number of bonds between the collector and the kaolinite show good consistency with the actual flotation results of the three collectors, which can be used as a screening index for kaolinite flotation collectors.Keywords:kaolinite;flotation;collector;adsorption;DFT calculation
研究领域:
化学工程
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材料科学
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表面化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2021
·Vol. 21
·期 2
·775-783
·
IF 3.308
Du Huihui,Du Jingwei,Liu Fangyi,Zhang Yanhuan,Guo Hanwen,Wan Dan
Purpose Antibiotics often coexist with heavy metals in contaminated soils, making their behaviors more complicated than their individual presences. Sorption to soil components deeply affects the mobility, bioavailability, and fate of contaminants. However, limited studies have investigated the cosorption characteristics of tetracycline (TC) and heavy metals to typical soil minerals, particularly phyllosilicates. Materials and methods This study investigates the effect of Cd(II) on TC sorption by kaolinite (Kao, 1:1-type) and montmorillonite (Mont, 2:1-type) via isothermal adsorption, coupled with X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Results and discussion Isothermal results show that TC sorption on both kaolinite (Kao, 1:1-type) and montmorillonite (Mont, 2:1-type) is little affected by Cd(II) at pH 4.5 but increases significantly at pH 8.5. The overall effect of Cd(II) on TC sorption depends on the intensities of two positive processes, i.e., (1) the formation of soluble Cd-TC complex increases sorption compared to free TC molecules and (2) the formation of a ternary clay-Cd-TC complex at clay variable edge sites increases sorption, and one negative process, i.e., competition of Cd(II) with cationic and zwitterionic TC species at the permanently charged sites decreases sorption. XRD analyses demonstrate that TC intercalates into the interlayer ( d 001 = 18.7 Å) of Mont as one monolayer parallel molecule both with and without Cd(II) but adsorbs predominately on external surface of Kao. FTIR results suggest a flat-lying horizontal configuration of adsorbed TC molecules on clays, accompanied by a strong complexation between the carbonyl and amino groups of TC molecules and the surfaces. Besides, the presence of Cd(II) more or less facilitates this complexation. Conclusions We propose that Cd(II) can significantly promote TC adsorption on clay minerals at alkaline pH rather than acidic pH. TC and Cd(II) interact intensely and form strong surface complexation on clay surfaces. Hence, coexistence with Cd(II) may lower the mobility and thus the bioavailability of TC in alkaline soils, which provides a new direction for soil remediation by regulating soil pH using alkaline materials. Graphical abstract
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）