Halloysite nanotubule clay for efficient water purification

Zhao, Yafei; Abdullayev, Elshad; Vasiliev, A. N.; Lvov, Yuri

doi:10.1016/j.jcis.2013.05.072

Cited by 195 publications

(106 citation statements)

References 39 publications

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“…The Langmuir model assumes that there is no interaction between adsorbate molecules and the monolayer localizes on a homogeneous adsorbent surface with identical adsorption sites, while the Freundlich model describes the adsorption of interacted adsorbate molecules on a heterogeneous surface and monolayer coverage is not the only way for adsorption. 18,19 The Langmuir model fits the equilibrium data very well, and the correlation coefficients are higher than Freundlich fitting, which indicates that the Langmuir model describes the adsorption better than the Freundlich model in this system (SI, Figures S7, S8 and Table S2). For both hybrids and HNTs, the free energies for adsorption are negative regardless of the temperature, and decrease with increasing temperature, indicating that the adsorption process is thermodynamically spontaneous and becomes more favorable at higher temperatures.…”

Section: ¹1mentioning

confidence: 88%

“…The zeta potential of HNTs is found to be negative for pH higher than 2.8, which enables the HNTs to adsorb cationic dyes from wastewater. 18 The zeta potentials of P(AAm-co-DADMAC) solution, HNTs, and hybrids in pure water were determined by a zeta potential analyzer (ELSZ Otsuka Electronics Co., Ltd.), and were calculated to be 3.4 « 0.3, ¹53.8 « 0.8, and ¹48.0 « 0.5 mV, respectively. The pH values of the solution in the abovementioned zeta potential measurements were determined by a pH meter (F-52 HORIBA, Ltd.), and were calculated to be 6.7, 6.9, and 6.9, respectively.…”

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confidence: 99%

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Halloysite Nanotube/Polyelectrolyte Hybrids as Adsorbents for the Quick Removal of Dyes from Aqueous Solution

Tao

Higaki

Ma³

et al. 2015

Chem. Lett.

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Novel organic/inorganic hybrids composed of halloysite nanotubes (HNTs) and a cationic polymer were prepared through a simple mixing method. The hybrids provide more gaps for water permeation than the pristine HNTs when used as column adsorbents, and quick dye removal from polluted water was achieved.Dyes are widely used in industrial products including paper, textile, printing, plastic, etc. However, because of their complex substituted aromatic groups, most dyes show great resistance to the decomposition by chemical, physical, and biological treatments. Furthermore, their degradation may generate other undesirable toxic and carcinogenic products. 13 Adsorption has been applied as an efficient and economical approach for dye removal from wastewater.4,5 Many low-cost naturally occurring mesoporous adsorbents have been widely investigated for water purification, such as zeolites, kaolinite, and montmorillonite. However, none of them show high adsorption capacity for both positive and negative dyes. 611 Recently, halloysite nanotube (HNT) nanoclay materials have attracted great interest in academia and industry due to their hollow tubular structure, high surface area, and the asymmetric chemical structures of the inner and outer surfaces. HNTs have wrapped layer morphologies with negatively charged SiOH on the external surface and positively charged AlOH on the inner surface, which enable the HNTs to adsorb both positive and negative pollutants. 1215Although HNTs show significant adsorption capacity for various dyes, they cannot be directly used for dye removal from aqueous solution, because HNTs form a stable colloidal suspension in water, making their separation from water very difficult. Besides, compacted HNTs do not supply enough pathways for water permeation during column filtration. Recently, HNT/polymer (alginate, chitosan) hybrid beads have been applied to solve these problems for dye removal applications. However, the preparation procedures are complicated and post-treatment is necessary. 16,17 In order to overcome the drawbacks of HNTs mentioned above, we designed a novel HNT/polyelectrolyte hybrid adsorbent, which is prepared by simple mixing of pristine HNTs and a cationic synthetic copolymer of poly(acrylamide-codiallyldimethylammonium chloride) [P(AAm-co-DADMAC)]. The effects of adsorbent dose, temperature, initial concentration, and contact time on the adsorption of cationic dye Basic Blue 7 (BB7) from aqueous solution were investigated. The equilibrium isotherms, kinetics data, and thermodynamic parameters were calculated to understand the adsorption mechanism of BB7 onto the hybrids.HNTs were purchased from Sigma-Aldrich and dried at 150°C for 3 days under vacuum before use. HNTs have diameters of 3070 nm with lengths of 200 nm to 2¯m. P(AAm-co-DADMAC) (acrylamide composition: 55 wt %) 10 wt % aqueous solution was purchased from Sigma-Aldrich and used as received (Figure 1a). 3 g of HNTs were dispersed in deionized water (20 mL) by sonication for 15 min. Subsequently, 7.9 mg mL ¹1 P(AAm-co-DADMA...

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Section: ¹1mentioning

confidence: 88%

mentioning

confidence: 99%

Halloysite Nanotube/Polyelectrolyte Hybrids as Adsorbents for the Quick Removal of Dyes from Aqueous Solution

Tao

Higaki

Ma³

et al. 2015

Chem. Lett.

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“…However, the natural HNT has no selective absorption for oil and water. Hence, it can only be used to remove water-soluble cationic and anionic contaminants from wastewater [57]. Excitingly, the resultant superhydrophobic HNTs (S-HNTs) that have unique water resistance property and strong oil-absorbing capacity are promisingly suitable as a filter for oil/water separation.…”

Section: Application Analysis Of Superhydrophobic Hntsmentioning

confidence: 99%

Preparation of Robust Superhydrophobic Halloysite Clay Nanotubes via Mussel-Inspired Surface Modification

et al. 2017

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Abstract:In this study, a novel and convenient bio-inspired modification strategy was used to create stable superhydrophobic structures on halloysite clay nanotubes (HNTs) surfaces. The polydopamine (PDA) nanoparticles can firmly adhere on HNTs surfaces in a mail environment of pH 8.5 via the oxidative self-polymerization of dopamine and synthesize a rough nano-layer assisted with vitamin M, which provides a catechol functional platform for the secondary reaction to graft hydrophobic long-chain alkylamine for preparation of hierarchical micro/nano structures with superhydrophobic properties. The micromorphology, crystal structure, and surface chemical composition of the resultant superhydrophobic HNTs were characterized by field emission scanning electron (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The as-formed surfaces exhibited outstanding superhydrophobicity with a water contact angle (CA) of 156.3 ± 2.3 • , while having little effect on the crystal structures of HNTs. Meanwhile, the resultant HNTs also showed robust stability that can conquer various harsh conditions including strong acidic/alkaline solutions, organic solvents, water boiling, ultrasonic cleaning, and outdoor solar radiation. In addition, the novel HNTs exhibited excellent packaged capabilities of phase change materials (PCMs) for practical application in thermal energy storage, which improved the mass fractions by 22.94% for stearic acid and showed good recyclability. These HNTs also exhibited good oil/water separation ability. Consequently, due to the superior merits of high efficiency, easy operation, and non-toxicity, this bionic surface modification approach may make HNTs have great potentials for extensive applications.

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“…Tubos de haloisita (Figura 1) têm como estrutura paredes multicamadas com superfície externa carregada negativamente por grupos Si-OH e grupos positivos Al-OH na superfície interna (a pH entre 4 e 9). Esta morfologia bivalente com separação espacial de superfície negativa e positiva faz com que os tubos de haloisita sejam um adsorvente promissor para uma variedade de poluentes, tanto aqueles que apresentam cargas positivas como negativas [3]. Pesquisas anteriores mostraram que os argilominerais apresentam limitações quanto à eficiência de separação e seletividade para alguns tipos de adsorvatos, e que esta limitação pode ser reduzida através de tratamentos químicos adequados, capazes de introduzir grupos funcionais muito reativos e seletivos na sua superfície e nas regiões interlamelares [5].…”

Section: Introductionunclassified

Funcionalização E Caracterização Do Argilomineral Haloisita Para Remediação Ambiental

Santos¹,

Mello²

2018

ABM Proceedings

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ResumoEste trabalho tem como objetivo a síntese de materiais híbridos nanoestruturados à partir da funcionalização do argilomineral haloisita com (3-aminopropil)trietoxissilano (APTES) para aplicação em processos de adsorção. A rota de modificação baseouse na acidificação e posterior reação química entre as hidroxilas superficiais da haloisita e os grupos hidrolisáveis de APTES na presença de tolueno sob refluxo. Haloisita em sua forma natural e modificada foi caracterizada por análise termogravimétrica (TG), área superficial específica (BET), espectroscopia de infravermelho (FTIR) e difração de raios X (DRX). A quantidade de APTES enxertado, calculado através da análise termogravimétrica foi de 7,32% para a amostra funcionalizada previamente acidificada e 6,50% para a amostra funcionalizada sem pré tratamento ácido. A área superficial das amostras diminuiu com a funcionalização. As amostras funcionalizadas exibiram novas bandas características de grupos de APTES no espectro obtido por FTIR confirmando a ocorrência da funcionalização do organosilano na haloisita. A análise de DRX indicou que a estrutura original não foi alterada após a funcionalização. Palavras-chave: Haloisita, Funcionalização, APTES, Adsorção. FUNCTIONALIZATION AND CHARACTERIZATION OF CLAY MINERAL HALLOYSITE FOR ENVIRONMENTAL REMEDIATION AbstractThe present work was aimed at synthesizing nanostructured hybrid materials derived from the functionalization of halloysite clay with ligand (3-aminopropyl)triethoxysilane) (APTES) for application in adsorption processes. The modification routes were based on the acidification and subsequent grafting reaction between hydroxyl groups present on clay surface and the hydrolyzable alkoxy group of the APTES in dry toluene under reflux. Halloysite in their natural form and after structural modification were characterized by thermal analysis (TG), specific surface area (BET method), infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The amount of grafted APTES, calculated through thermogravimetric analyses was of 7,32% for functionalized and acidified sample and 6,50%for functionalized simple. The specific surface areas of clay samples decreased upon grafting. Functionalized samples exhibit some new FTIR peaks of the groups of APTES confirm the occurrence of the functionalized organosilane in the clay structure. The XRD results showed that the functionalization process did not affect the crystallographic structure of the halloysite.

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Halloysite nanotubule clay for efficient water purification

Cited by 195 publications

References 39 publications

Halloysite Nanotube/Polyelectrolyte Hybrids as Adsorbents for the Quick Removal of Dyes from Aqueous Solution

Halloysite Nanotube/Polyelectrolyte Hybrids as Adsorbents for the Quick Removal of Dyes from Aqueous Solution

Preparation of Robust Superhydrophobic Halloysite Clay Nanotubes via Mussel-Inspired Surface Modification

Funcionalização E Caracterização Do Argilomineral Haloisita Para Remediação Ambiental

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