Crystal violet adsorption by oppositely twisted heat-treated halloysite and pecoraite nanoscrolls

Krasilin, Andrei A.; Данилович, Д. П.; Yudina, Elena B.; Bruyère, Stéphanie; Ghanbaja, Jaâfar; Иванов, В. К.

doi:10.1016/j.clay.2019.03.007

Cited by 38 publications

(16 citation statements)

References 72 publications

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“…The 400–800 °C range contained intense but broad endo‐effect with mass loss up to 9% in air. This effect could be caused by volume dehydroxylation [7c] together with structural transformation of sample into sepiolite‐like Mg 4 Si 6 O 15 (OH) 2 phase shown by Krasilin et al [11d] . Because sepiolite differs from Mg 3 Si 2 O 5 (OH) 4 chrysotile by Mg : Si ratio, this transformation could also be accompanied with partial amorphization.…”

Section: Resultsmentioning

confidence: 97%

“…Thermal studies carried out on natural [3a] and synthetic [5a,7c,23] phyllosilicate nanoscrolls reported on two principle effects: intense endothermic dehydroxylation at around 630 °C and exothermic forsterite crystallization around 820 °C. First effect was often interpreted as structure collapse, however, nanotubular morphology can still be preserved [11d] until silicate crystallization.…”

Section: Introductionmentioning

confidence: 99%

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Thermal behavior of Mg−Ni‐phyllosilicate nanoscrolls and performance of the resulting composites in hexene‐1 and acetone hydrogenation

et al. 2020

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Here we report on the thermal properties of Mg−Ni‐phyllosilicate nanoscrolls as a promising precursor for production of Ni/silicate composite catalysts. Spontaneous scrolling of the phyllosilicate layer originating from size difference between metal‐oxygen and silica sheets provides high surface area of the catalyst. Metal nanoparticles can be obtained directly from the matrix by H2 reduction. The phyllosilicate structure passed through a number of transformations including partial dehydroxylation with formation of sepiolite‐like phase followed by silicate or oxide crystallization. Temperature ranges of these transitions overlapped with the reduction process sophisticating the H2 consumption profiles. In particular, some amount of Ni2+ got sealed up by the sepiolite structural features, that opened a path for the tuning of Ni0 : Ni2+ ratio of the catalyst. An increase of Ni content in the system yielded a decrease in the metal nanoparticles sizes due to both high intensity of nucleation and type of residual matrix. Ni nanoparticles size distribution and specific surface area of the composite catalysts governed conversion rate of hexene‐1 and acetone hydrogenation. In the view of the turnover frequency MgNi2Si2O5(OH)4 precursors were slightly more preferable than pure Ni3Si2O5(OH)4.

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Section: Resultsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Thermal behavior of Mg−Ni‐phyllosilicate nanoscrolls and performance of the resulting composites in hexene‐1 and acetone hydrogenation

et al. 2020

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“…As shown in [7], phyllosilicate nanoscrolls with a pecoraite structure have a small positive zeta potential < 30 mV, hence, they are prone to aggregation. During the sample preparation, the substrate can become contaminated with particle aggregates, so that small particles, or even layers of such particles, which are softer than the substrate, appear under the nanoscroll.…”

Section: In-situ Tem Indentationmentioning

confidence: 99%

“…Scrolled structures may also be formed from a thin, unstressed film to compensate the surface energy difference of the top and bottom sides of the film, [4]. Owing to their composition, structure and morphology, phyllosilicate nanoscrolls are considered as promising adsorbents and capsules [5][6][7], catalysts [8][9][10][11][12] and reinforcing components of composite materials [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Young’s modulus of phyllosilicate nanoscrolls measured by the AFM and by the in-situ TEM indentation

Khalisov¹,

Лебедев²,

Poluboyarinov³

et al. 2021

Nanosystems: Phys. Chem. Math.

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“…In this study, both nanoclays were dispersed at 1800 rpm for 20 h. Laponite dispersions were prepared at 18 g•L −1 to avoid gel formation in distilled water. The halloysite nanoclay was heat-treated for 24 h at 220 • C [33,34] and dispersed in distilled water at 25•L −1 . In both nanoclay dispersions, pH was adjusted to −4 using 37% HCl [35,36].…”

Section: Synthesis Processmentioning

confidence: 99%

Halloysite and Laponite Hybrid Pigments Synthesis with Copper Chlorophyll

et al. 2021

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Sustainable and green materials have been studied in dye and pigment productions to reduce their environment impacts from being produced and applied. Although natural dyes are an excellent choice to move from agrowaste, some improvements must be made before they are applied given their poor fastness. One way of improving natural dye properties is their adsorption into nanoclay structures to give hybrid pigments. This work used tubular halloysite and laminar laponite to adsorb and stabilize natural copper chlorophyll. With a statistical design of experiments, we observed interactions between synthesis factors, such as pH, ionic strength, and surfactant or silane modification. Cool hybrid pigments with high TSR (%) values and a wide color range were obtained by using dispersions with only distilled water at room temperature. Successful chlorophyll adsorption on both nanoclay surfaces took place by XRD and DTA analyses. The maximum natural dye absorption for both nanoclay types took place under acid conditions, pH 3–4, and in the presence of mordant. The TSR (%) improved by the silane pH interaction, and halloysite hybrid pigments obtained higher TSR values than the laponite ones. Finally, a wide chromatic green color range was obtained with the surfactant modification in both nanoclays, and the color fastening was also improved in the hybrid pigments application. The samples generated with 10% of hybrid pigments from both nanoclays and an Epoxy bioresin, show higher colorfastness than the sample with the natural chlorophyll, due to the nanoclays–dye interaction and protection.

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Crystal violet adsorption by oppositely twisted heat-treated halloysite and pecoraite nanoscrolls

Cited by 38 publications

References 72 publications

Thermal behavior of Mg−Ni‐phyllosilicate nanoscrolls and performance of the resulting composites in hexene‐1 and acetone hydrogenation

Thermal behavior of Mg−Ni‐phyllosilicate nanoscrolls and performance of the resulting composites in hexene‐1 and acetone hydrogenation

Young’s modulus of phyllosilicate nanoscrolls measured by the AFM and by the in-situ TEM indentation

Halloysite and Laponite Hybrid Pigments Synthesis with Copper Chlorophyll

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