APPLIED CLAY SCIENCE
·
2021
·
IF 5.467
Junming Zhou,Hongmei Liu,Dong Liu,Peng Yuan,Hongling Bu,Peixin Du,Wenxiao Fan,Mengyuan Li
Weathered crust elution-deposited rare earth (WED-RE) ores are important rare earth element (REE) resources around the world. In these ores, the REE are believed to mainly exist as exchangeable REE(III) ions on the surfaces of clay minerals, such as tubular halloysite and platy kaolinite . However, the mechanisms underlying the sorption and desorption of REE(III) ions on clay minerals in the environment of weathered crusts remain ambiguous. In this study, the sorption/desorption characteristics of Eu(III) ions onto halloysite and kaolinite were investigated. The results revealed that Eu(III) was adsorbed onto both clay minerals through inner-sphere complexation and outer-sphere complexation, where the former was the primary sorption mechanism. Halloysite displayed a higher sorption capacity for Eu(III) than kaolinite in a weakly acidic environment (pH 4–6). The desorption efficiency increased with the increasing concentration of NH 4 + ions. When the NH 4 + concentration was 0.002 mol/L, which is similar to the typical cation concentration of groundwater/rainwater, the amount and rate of Eu(III) desorption from halloysite were lower than those from kaolinite. The desorption of Eu(III) ions from the two clay minerals is proposed to be governed by the attraction between the outer-sphere complexes and clay minerals when the NH 4 + concentration is 0.002 mol/L. Therefore, halloysite has a higher sorption capacity and stronger retention capacity for Eu(III) than kaolinite, which suggests that halloysite may play a greater role in REE(III) enrichment in WED-RE ores than kaolinite owing to the similar chemical properties of REE(III) ions. The fundamental results obtained in this study afford new insights into the migration of REE and the role of clay minerals in REE enrichment during ore formation.
研究领域:
地质学
·
环境科学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Qiang Wang,Haibo Liu,Peixun Zhai,Fuwei Sun,Tianhu Chen,Ziyang Chu,Dong Chen,Xuehua Zou
In this study, a new low-cost carbon-based material was prepared via the carbonization of methylene blue adsorbed halloysite (CMH) at different temperatures in a nitrogen atmosphere, which was named CMH-T (T-Temperature). The performance of CMH-T was explored and the effects of initial pH values, catalyst dosage, phenol (PE) concentrations, peroxymonosulfate (PMS) concentrations, and water background compounds on PE degradation were investigated systematically. The results indicated that CMH800 exhibited the best performance to activate PMS for degrading PE. Specifically, 92% PE was degraded within 30 min with a constant rate ( k obs ) of 0.1186 min −1 in the CMH800/PMS system. Furthermore, CMH800 was efficient over a wide pH range (pH 3–9) and showed a slight inhibition to inorganic anions. Quenching experiments, electron spin resonance (ESR) analysis, and electrochemical analysis confirmed that PE was degraded through non-radical pathways dominated by single oxygen ( 1 O 2 ) and mediated electron transfer processes in the CMH800/PMS system. In addition, the predicted toxicity of intermediates through ECOSAR software based on QSAR (Quantitative Structure - Activity Relationship) model indicated that most of the intermediates had a low risk to water environment. Therefore, the CMH800 has a good potential for wastewater treatment applications.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Hongliang Wei,He Wang,Huijuan Chu,Jingjing Li
In this work, a kind of slow-release and water-retention fertilizer was fabricated by free radical copolymerization of potato starch, acrylic acid, acrylamide, and β-cyclodextrin modified by maleic anhydride, accompanying halloysite nanotubes whose cavities were enlarged by acidification and loaded with urea in advance. The fertilizer was characterized by FTIR, TGA , SEM, TEM, and XRD. Its swelling behavior in distilled water and salt solutions as well as the ability to hold water was studied by weighing method. Finally, its controlled-release behavior to urea was investigated. The results suggested the as-prepared fertilizer had good abilities to retain water and control urea release. Moreover, the addition of halloysite helped to improve the release properties of the fertilizer. The study on urea release kinetics indicated the release behavior of urea in water was controlled by its concentration, whereas the release behavior of urea in soil fitted with Fickian diffusion mechanism.
研究领域:
农业科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Minerals
·
2018
·Vol. 8
·期 7
·296
·
IF 1.835
Jing Ouyang,Dawei Mu,Yi Zhang,Huaming Yang,Steven L. Suib
Barium carbonate (BaCO3) materials with the controllable morphology of nanoparticles were selectively loaded into the lumen halloysite nanotubes (abbreviated as Hal) by a urease assisted catalytic implementation strategy. The Hal mineral was pre-treated through leaching by hydrochloric acid (abbreviated as A-Hal), resulting in increased defect sites and zeta potential. The negatively charged urease was loaded inside the positively charged A-Hal lumen, and then through the decomposition of urea catalyzed by urease to produce carbonate ions and ammonia. When Ba2+diffused in, BaCO3particles were selectively synthesized in the lumen of A-Hal, the pore channels of A-Hal effectively controlled the growth and aggregation of BaCO3nanocrystals and their geometrical morphology. The obtained BaCO3/A-Hal-T was characterized by transmission electron microscopy, Fourier transformation infrared spectroscopy and X-ray diffraction, differential scanning calorimetry-thermogravimetry (DSC-TG). The BaCO3/A-Hal-T may provide a candidate for potential applications.Keywords:halloysite;urease;barium carbonate;selective decoration;nanoreactors
研究领域:
材料科学
·
生物催化
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产品关联
DOI
高影响因子
Polymers
·
2018
·Vol. 10
·期 10
·1171
·
IF 2.935
Xiandong Zhang,Guangshun Wu
The quality of interphase in carbon fibers (CFs) composites makes a key contribution to overall performance of composites. Here, we achieved for the first time the chemical grafting of halloysite nanotubes (HNTs) with amino or carboxyl groups onto the CFs surface aiming to increase composites interfacial strength. HNTs were grafted using 3-aminopropyltriethoxysilane (APS) followed by succinic anhydride treatment, and HNTs with amino groups (HNT–NH2) or carboxyl groups (HNT–COOH) were separately introduced into the interphase of composites. Functional groups of HNTs and fiber surface structures were characterized, which confirmed the modification success. The wettability between the modified CFs and resin have been enhanced obviously based on the improved fiber polarity and enhanced surface roughness by the introduced two functionalized HNTs with the uniform distributions onto fiber surface. Moreover, interfacial properties and anti-hydrothermal aging behaviors of modified methylphenylsilicone resin (MPSR) composites were improved significantly, especially for HNT–COOH grafting. In addition, the interfacial reinforcement mechanisms for untreated and modified CF composites are discussed and compared.Keywords:carbon fibers;surface grafting;halloysite nanotubes;polymer composites;interface
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
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jing Zhang,Qinfu Liu,Mingyi Huang
Halloysite is a natural aluminum-rich nano-sized clay mineral, which can offer the aluminum source to synthesize aluminum nitride (AlN) in a low-cost and environmentally friendly manner. The micron-sized AlN with different morphology and structure, including self-assembled pine-like aggregates, hollow bayberry-like spheres, and high aspect ratio whiskers, were successfully synthesized at 700 °C under nitrogen atmosphere using natural hydrated halloysite (10 Å HNT). These three kinds of varying morphological AlN formed by different mechanism. The self-assembled-AIN pine-like aggregates formed by in-situ nitrogen substitution within the Al-O octahedra of 10 Å HNT thermal fragmentation through self-assembly. The formation of the bayberry-like hollow spheres is governed by a gas–liquid reaction pathway, whereas the development of whiskers with a high length-to-diameter ratio is driven by a gas–liquid-solid mechanism. The morphological comparison of AlN synthesized from 10 Å HNT with 7 Å HNT further confirms the validity of the in-situ substitution mechanism we previously proposed, as well as reflecting the critical influence of halloysite hydration state on structural evolution of AlN. This study offers a new insight into tailoring AlN nanostructures using clay mineral templates, with promising applications in thermally conductive composites and electronic packaging materials.
研究领域:
材料科学
·
无机非金属材料
·
纳米结构材料
·
陶瓷材料
·
复合材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Pan Wang,Mingliang Du,Ming Zhang,Han Zhu,Shiyong Bao,Meiling Zou,Tingting Yang
Here we proposed a facile strategy to synthesize multi-layered gold nanoparticles/polyaniline/halloysite nanotubes (AuNPs/PANI/HNTs) nanostructures used for electrochemical sensors. The PANI/HNTs were firstly obtained by making use of the in situ polymerization as well as employing the thioglycollic acid (TA) as the dopant, thereafter, Au ions were anchored to TA and then reduced by PANI. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) observations implied that a large amount of uniform AuNPs were immobilized on the PANI/HNTs. The as-prepared AuNPs/PANI/HNTs nanostructures were also characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the results confirmed the successful synthesis of AuNPs/PANI/HNTs nanostructures and explained the reactions in depth as well. Further investigations suggested that the AuNPs/PANI/HNTs nanostructures with well-separated AuNPs exhibited high electrochemical performance as sensors to detect hydrogen peroxide (H 2 O 2 ).
研究领域:
材料科学
·
分析化学
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产品关联
DOI
高影响因子
Journal of Energy Storage
·
2021
·
IF 6.583
Tiantian Zhang,Shi Juan,Wang Yi,Zhenqian Chen
Halloysite nanotube (HNT), a natural and environmentally friendly low-cost material with significant reserves, has become one of promising candidates for preparation of form-stable composite PCM with satisfactory thermal properties owing to their hollow tubule structure and high surface area. The present work prepared the form-stable composite with HNTs and acid etching HNTs (A-HNTs) and compares the properties closely related to thermal energy storage application. Specifically, the micromorphology, thermal properties, shape-stabilized properties, as well as thermal conductivities of the composite materials were characterized by utilizing SEM, TEM, FTIR, DSC, BET, and Hot-disk wire methods, respectively. The results showed that the n-octadecane can both adhere on the inner lumen and the outer wall of HNTs and A-HNTs, while the A-HNTs possess significantly improved absorption thanks to the fact that the pore volume of A-HNTs was enlarged by 19.2% in comparison with HNT, which empowers the extra 5.8% phase transition enthalpy of n-octadecane@A-HNT. In addition, the composite PCMs have a good long-term thermal stability based on multi-cycle heat absorption and release further highlights the potentials in thermal storage application.
研究领域:
材料科学
·
纳米科技
·
能源材料
·
热力学
·
环境友好材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 83
·44197-44202
·
IF 3.708
Huilin Lun,Jing Ouyang,Huaming Yang
Natural halloysite nanotubes (HNTs) modified with 3-aminopropyltriethoxysilane were used as an aspirin carrier. The structure, drug loading and release profiles of samples were characterized by X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and UV-spectrophotometry. The Higuchi model Q = kt0.5 was employed to analyze the dissolution data in detail. The results indicated that the modification of HNTs could improve the amount of aspirin from 3.84 to 11.98 wt%. The physical state of aspirin was nanocrystalline and amorphous affected by the confined space of HNTs, which significantly enhanced the dissolution rate created by a burst release within the first hour. The linearity of the Higuchi equation indicated that the aspirin release mechanism for modified HNTs was fitted to Fick's diffusion and the dissolution rate was slower than that of natural HNTs. The as-synthesized N-HNTs could have interesting potential application in drug carrier systems.
研究领域:
药剂学
·
纳米医学
·
生物材料
·
药物递送系统
·
药动学
✓ 已验证
DOI
高影响因子
Sustainable Energy & Fuels
·
2022
·Vol. 6
·期 9
·2368-2376
·
IF 6.813
Yanping Xiang,Kangyu Zhao,Shuolin Zhou,Wenguang Zhao,Zhijuan Zeng,Xiaoting Zhu,Xianxiang Liu
The catalytic transformation of biomass derived compounds into valuable liquid fuels has received considerable attention in the past few years. In this work, sulfonic acid grafted halloysite nanotubes (HNTs-SO3H) were facilely synthesized via functionalizing the halloysite nanotubes with 1,3-propanesultone, and the physico-chemical properties of the synthesized catalysts were analyzed by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 adsorption isotherm techniques, etc. The characterization results revealed that the organic–inorganic mesoporous materials preserved the tubular structure of the halloysite nanotubes and were equipped with active sulfonic acid sites. The as-synthesized catalyst was employed for the catalytic conversion of 5-hydroxymethylfurfural (HMF) to biofuel 5-ethoxymethylfurfural (EMF) under solvent-free conditions. Response surface methodology (RSM) with Box–Behnken design (BBD) was used to investigate the influence of the reaction conditions such as reaction temperature, reaction time and catalyst dosage on EMF yield. An excellent EMF yield of 86.4% and HMF conversion of 99.3% could be achieved at 126 °C for 35 minutes over the HNTs-SO3H catalyst. Furthermore, the kinetics of the conversion of HMF to EMF was also studied, and the kinetic modeling results indicated that this reaction follows pseudo-first-order kinetics, and the activation energy obtained was 60.12 kJ mol −1.
研究领域:
化学工程
·
催化材料
·
可再生能源
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2019
·
IF 2.943
Xiaoqian Mi,Liuyue Zhong,Fang Wei,Liang Zeng,Junheng Zhang,Daohong Zhang,Tiwen Xu
Halloysite nanotubes-reduced graphene oxide hybrids (HRGO), prepared by simultaneous reduction and hybridization of graphene oxide with halloysite nanotubes , were incorporated in epoxy resin to improve the thermal and mechanical properties . The presence of HNTs effectively prevented the aggregation of RGO sheets in epoxy matrix. The thermal stability and thermal conductivity of HRGO/epoxy composites were enhanced. The epoxy composites with the addition of HRGO exhibited significant enhancements of tensile strength , storage modulus and fracture toughness . The improved dispersion of HRGO in epoxy matrix resulted in the better interfacial load transfer efficiency. The improvement in fracture toughness was disclosed of crack deflection and crack pinning mechanisms.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Song Xu,Yan Gao,Ling Zhao,Huaijie Cao,Junxi Zhang
Solely inorganic silica (SiO 2 ) coating cannot provide long-term corrosion protection on metal due to structural defects. Herein, acidified Halloysite (Hal) was proposed and the Hal tubes were incorporated into SiO 2 sol coating for enhancing corrosion resistance on AZ31B magnesium (Mg) alloy. SiO 2 sol originated from the hydrolysis of water glass (Sodium silicate). With improved interaction between Hal and SiO 2 , the cracks and structural defects in cured SiO 2 coating can be reduced. As a result, the impedance modulus at 0.01 Hz (|Z| 0.01 Hz ) of the acidified Hal/SiO 2 composite coating (AG coating) increased to 10 9 Ω·cm 2 , outperforming 2 orders of magnitude higher than pure SiO 2 coating (pure coating) counterpart. The corrosion current density decreased to 9.33×10 –12 A·cm -2 . Besides, the AG coating offered stable corrosion resistance after immersion tests for 30 days, which was comparable to anti-corrosive polymer coating. The release of amorphous SiO 2 from acidified Hal reduced the internal stress. The H + on Hal induced a decrease of pH and adsorption of residual Na + , thereby improving structural integrity and water resistance of SiO 2 coating. Differing from other fillers (CNTs, graphene, MXene), this work proposed a low-cost Hal tube as filler for designing inorganic coating for corrosion protection on Mg alloy. It also shed insight into understanding the underlying corrosion protection mechanism of inorganic SiO 2 coating on metal.
✓ 已验证
产品关联
DOI
高影响因子
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