Recent progress in dispersion of palygorskite crystal bundles for nanocomposites

Tian

et al. 2016

Sci Rep

Self Cite

A mesoporous hybrid silicate microsphere with superior adsorption performance has been successfully synthesized by employing an “all-into-one” strategy and a simple one-pot hydrothermal process using naturally abundant low-grade red palygorskite (PAL) clay as raw material in the presence of non-toxic SiO32− and Mg2+ ions. As is expected, both the PAL and associated minerals transformed into a new amorphous mesoporous hybrid silicate microsphere without using any additional pore-forming template. The mesoporous silicate microsphere shows a large pore size of 37.74 nm, high specific surface area of 489.81 m2/g (only 54.67 m2/g for raw PAL) and negative surface potential of −43.3 mV, and its maximum adsorption capabilities for Methylene bule (MB) and Crystal violet (CV) reach 407.95 mg/g and 397.22 mg/g, respectively. Meanwhile, 99.8% of MB (only 53% for raw PAL) and 99.7% of CV (only 43% for raw PAL) were sucessfully removed from 200 mg/L of initial dye solution by only using 1 g/L of the adsorbent. In addition, the spent adsorbent can be easily regenerated and repeatly reused for muptiple cycles. The study on adsorption mechanism revealed that electrostatic attraction, hydrogen bonding and chemical complexing interactions are the main factors contributed to the high dye adsorption.

mentioning

confidence: 99%

All-into-one strategy to synthesize mesoporous hybrid silicate microspheres from naturally rich red palygorskite clay as high-efficient adsorbents

Tian

et al. 2016

Sci Rep

Self Cite

“…According to the results, in the presence of SHMP less than 15 % (3 g) of the milled sample remained on the 20-micron sieve, while 70 % (14 g) of the milled sample without SHMP remained on the 20-micron sieve. With respect to the literature, various chemical dispersants such as sodium hexametaphosphate and surfactants improve the dispersion and prevent the aggregation of nanoparticles (Chen et al 2014;Wang and Wang 2016). Thus, as a result of this mechanism, finer particles were gained.…”

Section: Effect Of Sodium Hexametaphosphatementioning

confidence: 96%

Heavy metals adsorption by nanozeolites: effect of sodium hexametaphosphate

2016

In this study, for the first time, sodium hexametaphosphate (SHMP) was used as a dispersant in the production of nanozeolites. In addition, the effect of SHMP on the adsorption of ion metals by nanozeolite was investigated. In order to characterize the prepared nanozeolite by a planetary mill, the scanning electron microscope (SEM) was used. The SEM photographs showed that the planetary mill could produce the nanoparticles of zeolites. Furthermore, according to the SEM and X-ray diffraction (XRD) results, the zeolite samples milled with SHMP have regular and fine particles in comparison with nanozeolites produced without SHMP. On the other hand, the nanozeolites produced with SHMP have high qualification. According to the size fraction results, in the presence of SHMP, less than 15 % (3 g) of the milled sample remained on the 20-micron sieve, while 70 % (14 g) of the milled sample without SHMP remained on the 20-micron sieve. Finally, a series of experiments was performed to study the effect of SHMP on the adsorption of nickel, cadmium and copper ions using nanoparticles of zeolite. As a result, the adsorption percentage of nickel and cadmium on nanozeolites pretreated by SHMP is higher for times less than 2 h and more than 6 h in comparison with nanozeolites not pretreated by SHMP. On the other hand, the effect of SHMP on the adsorption of copper by nanozeolite is not significant. This insignificant effect probably occurs due to the stronger interaction of Cu 2+ and AlO 4− than that of Cu 2+ and SHMP.

“…Les capacités d'échanges cationiques trouvées selon la méthode à l'ion cobaltihexamine ont été de 50,80% pour l'Actapulgite® contre 1,45% pour l'attapulgite purifiée. Les résultats des clichés MEB ont confirmé la structure fibreuse de la palygorskite qui est le minéral dominant dans l'attapulgite (Robertson;Murray, 2000;Rautureau et al, 2004;Sylla, 2015). Ceci a été également confirmé par les diffractogrammes obtenus aux rayons X.…”

Section: Capacité D'échange Cationiqueunclassified

Etude physico-chimique et minéralogique comparative des attapulgites de Mbodiène (Sénégal) et de Mormoiron (France)

Gueye¹,

Davy²,

Ndiaye³

et al. 2016

Int. J. Bio. Chem. Sci

La valorisation des ressources locales constitue un impératif afin d'atteindre des objectifs de développement durable. Cette étude a consisté à évaluer les caractéristiques physiques, chimiques et minéralogiques d'une argile provenant de Mbodiène (Sénégal), l'attapulgite, comparativement avec un médicament antidiarrhéique, constitué d'attapulgite, dénommé Actapulgite®. L'échantillon d'attapulgite brute a été purifié avec une solution de HNO 3 1M. Une étude morphologique effectuée par visualisation à la Microscopie Electronique à Balayage a montré pour les deux argiles étudiées, une structure fibreuse caractéristique de la palygorskite, représentant le minéral dominant. L'analyse chimique par la spectrométrie à fluorescence X a donné pour l'attapulgite purifiée : 65,69% Si,