Uso de la aproximación de Rothmund-Kornfeld para la descripción del intercambio catiónico binario en aluminosilicatos sintéticos de carga variable

Escudey, Mauricio; Förster, Juan E.; Galindo, Géraldine; Pizarro, Carmen

doi:10.4067/s0366-16442002000400005

Cited by 3 publications

(8 citation statements)

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“…1 shows the IR spectra of the products obtained at different preparation times by S-I and S-II. Once the mixing process of the precursors of both syntheses is ended, the IR spectra indicate the presence of three broad peaks at 1080, 968 and 590 cm − 1 , corresponding to the stretching of the Si-O and Si-O-Al bonds, which are consistent with the structure of proto-imogolite [28][29][30]. The presence of bands corresponding to proto-imogolite were observed until 24 and 48 h of the aging process for S-I and S-II, respectively, showing that formation time of each imogolite precursor depends on the conditions of each synthesis.…”

Section: Discussionmentioning

confidence: 65%

“…Bands at 990 and 939 cm − 1 correspond to the Si-O stretching vibrations, which are specific for developed tubular structures that appear incipiently within 24 and 48 h of aging and achieve complete definition after 48 and 72 h of reaction for S-I and S-II, respectively. The bands at 693 and 430 cm − 1 are associated with the O-Al-O and Al-OH groups, while the band doublet observed at 570 and 512 cm − 1 corresponds to O-Si-O groups [28][29][30]. The highest intensity and resolution of the bands is achieved at 96 h of aging in both syntheses, and remain unaltered after that time.…”

Section: Characterization Of the Precursors And Imogolitementioning

confidence: 78%

“…As the synthesis evolves in time, the bands characteristic of imogolite appear, which are assigned at 990, 939, 693, 570, 512 and 430 cm − 1 [28][29][30]. Bands at 990 and 939 cm − 1 correspond to the Si-O stretching vibrations, which are specific for developed tubular structures that appear incipiently within 24 and 48 h of aging and achieve complete definition after 48 and 72 h of reaction for S-I and S-II, respectively.…”

Section: Characterization Of the Precursors And Imogolitementioning

confidence: 99%

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Use of isoelectric point and pH to evaluate the synthesis of a nanotubular aluminosilicate

Arancibia‐Miranda

Escudey

Molina

et al. 2011

Journal of Non-Crystalline Solids

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To follow the synthesis of imogolite, transmission electron microscopy is needed. In this paper, the isoelectric point (IEP) and the aging pH are proposed as alternative methods. Two synthetic procedures were used (S-I and S-II), both involving a co-precipitation followed by an aging treatment where the aluminosilicate evolves from proto-imogolite (detected after the co-precipitation step), to imogolite; its formation is reached after 120 h (S-I) or 168 h (S-II) of aging, depending on the co-precipitation method used. In S-I the isoelectric point increases from 7.1 to 10.5, while in S-II it increases from 6.6 to 9.2 during the aging treatment. Additionally, a linear relationship between the IEP and the pH at different aging steps was found. That relationship may be used to follow the process of synthesis by simply measuring the pH, becoming an alternative to more complex methods.

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Section: Discussionmentioning

confidence: 65%

Section: Characterization Of the Precursors And Imogolitementioning

confidence: 78%

Section: Characterization Of the Precursors And Imogolitementioning

confidence: 99%

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Use of isoelectric point and pH to evaluate the synthesis of a nanotubular aluminosilicate

Arancibia‐Miranda

Escudey

Molina

et al. 2011

Journal of Non-Crystalline Solids

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“…Toward the end of the aging process the final morphology is tubular, showing unusually high IEP values for an aluminosilicates which can be explained only if a total dominance of ≡Al-OH on the external surface of imogolite is considered, in addition to a slight structural charge of imogolite [11][12][13] . It has been demonstrated that equilibrium pH and IEP during synthesis and aging processes present a highly significant linear correlation as IEP= -1.97*(pHrx) + 15.69, giving a very simple tool for characterization and identification of imogolite 11 .…”

Section: Introductionmentioning

confidence: 99%

“…Also has two types of surfaces, an outer surface dominated by aluminol groups (≡Al 2 -OH, ≡Al-OH) (see Figure 1b), which are positively charged over a wide pH range (3.0-10.5) and an inner surface formed by silanol groups (≡Si-OH) which is preferably negatively charged [11][12][13][14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

Nanotubular Aluminosilicates: A Case Study for Science and Industry

Arancibia‐Miranda¹,

Lillo²,

Escudey³

2013

J. Chil. Chem. Soc.

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The renewed interest in imogolite nanotubes, with structural similarities with carbon nanotubes (CNTs), has led to a new search of the potential of imogolite in the field of nanoscience. The applications of imogolite started being studied at the beginning of the 1970s, but the lack of technological development prevented a detailed study of this aluminosilicate. Furthermore, the strong incursion CNTs, which show exceptional structural characteristics and physical properties, left imogolite as the subject of secondary studies and applications in nanotechnology. This review, revise the scientific interest on imogolite from its discovery until the present, showing the main areas of research and development for this nanotube from a nanotechnological point of view.

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K - Ca - Mg binary cation exchange in saline soils from the north of Chile

2008

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The selectivities of the K–Ca and K–Mg cation exchange reactions were studied in batch experiments carried out with 7 Chilean saline sandy soils with low organic matter (OM) content, and rich in quartz and halite, by using the experimental Gaines and Thomas procedure and the semi-empirical Rothmund–Kornfeld approach. The soils present high reactivity to the exchange process in terms of CEC and a preference order from the surface for the cation of K > Ca > Mg. In addition, the existence of different types of exchange sites was determined; some were specific for determined cations and others presented free competition. The proposed exchange reaction for both equilibria was thermodynamically possible and the studied cations presented a decreasing mobility order K > Ca > Mg, which follows the increasing order of hydrated ionic radii. As for the Rothmund–Kornfeld semi-empirical approach, it can be employed on soils classified as Aridisol due to good fit with the experimental data. On the other hand, the Gaines and Thomas approach is only experimentally applicable since poses some restrictions concerning to salinity and carbonate contents in the studied soils.

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Uso de la aproximación de Rothmund-Kornfeld para la descripción del intercambio catiónico binario en aluminosilicatos sintéticos de carga variable

Cited by 3 publications

References 0 publications

Use of isoelectric point and pH to evaluate the synthesis of a nanotubular aluminosilicate

Use of isoelectric point and pH to evaluate the synthesis of a nanotubular aluminosilicate

Nanotubular Aluminosilicates: A Case Study for Science and Industry

K - Ca - Mg binary cation exchange in saline soils from the north of Chile

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