Luminescence behaviour and Raman characterization of dendritic agate in the Dereyalak village (Eskişehir), Turkey

The current study establishes the unprecedented involvement in the evolution and production of novel core-shell nanocomposites composed of nanosized titanium dioxide and aniline-o-phenylenediamine copolymer. TiO 2 @copoly(aniline and o-phenylenediamine) (TiO 2 @PANI-o-PDA) core-shell nanocomposites were chemically synthesized in a molar ratio of 5:1 of the particular monomers and several weights of nano-TiO 2 via oxidative copolymerization. The construction of the TiO 2 @PANI-o-PDA core-shell nanocomposites was ascertained from Fourier transform IR spectroscopy, UV-visible spectroscopy and XRD. A reasonable thermal behavior for the original copolymer and the TiO 2 @PANI-o-PDA core-shell nanocomposites was investigated. The bare PANI-o-PDA copolymer was thermally less stable than the TiO 2 @PANI-o-PDA nanocomposites. The core-shell feature of the nanocomposites was found to have core and shell sizes of 17 nm and 19-26 nm, respectively. In addition, it was found that the addition of a high ratio of TiO 2 nanoparticles increases the electrical conductivity and consequently lowers the electrical resistivity of the TiO 2 @PANI-o-PDA core-shell nanocomposites. The hybrid photocatalysts exhibit a dramatic photocatalytic efficacy of methylene blue degradation under solar light irradiation. A plausible interpretation of the photocatalytic degradation results of methylene blue is also demonstrated. Our setup introduces a facile, inexpensive, unique and efficient technique for developing new core-shell nanomaterials with various required functionalities and colloidal stabilities.

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“…This may arise from the buoyancy effect which can affect the measurement processes. Previous similar cases have been reported …”

Section: Resultssupporting

confidence: 74%

Fabrication of core–shell nanocomposites with enhanced photocatalytic efficacy

Al-Hussaini

Eltabie

Hassan

2018

Polymer International

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“…In chalcedony (including agate and carnelian) the presence of minor moganite is expected. Moganite is the monoclinic silica polymorph approved as a new mineral by the IMA in 1999 and identified by its main band at 501 cm −1 . In some rare case, objects carved in opal CT (cristobalite–tridymite) can be identified by the cristobalite band at 410 cm −1 .…”

Section: Introductionmentioning

confidence: 99%

Raman spectroscopy of minerals and mineral pigments in archaeometry

Bersani

Lottici

2016

J Raman Spectroscopy

146

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Minerals, as raw structural materials or pigments, play a fundamental role in archaeometry, for the understanding of nature, structure and status of an artefact or object of interest for cultural heritage. A detailed knowledge of the mineral phases is crucial to solve archaeological problems: Raman spectroscopy is a powerful investigation technique and has been applied extensively in the last 30 years on mineral identification and on pigment degradation. Here we report an updated review, covering the last decade, of the applications of Raman techniques to issues in which raw minerals, including mineral pigments, are involved. Particular attention is devoted to cases where the Raman analysis of minerals is deeper than a simple identification of the phases present in an archaeological or artistic object. Copyright © 2016 John Wiley & Sons, Ltd.

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“…Os resultados obtidos para as amostras de ágata do DMSJ encontram-se na tabela 1. O teor de SiO 2 varia de 92,52 a 97,95 (% peso), valores que de uma maneira geral são coerentes com o encontrado na literatura (Frondel, 1962;Paralı et al, 2011 ).…”

Section: Resultsunclassified

“…Marcantes são os valores de LOI (perda ao fogo) obtidos, que variam de 0,4 a 4,9 % peso. Amostras de ágata de procedências e idades distintas também apresentam variação considerável nos teores de LOI (Frondel, 1962;Hatipoğlu et al, 2011;Paralı et al, 2011). Além disso, as amostras de ágata dos diferentes geodos do DMSJ de uma maneira geral mostram variações significativas nos conteúdos de Al, Fe, Cu, Ni e Ba, entre outros elementos.…”

Section: Resultsunclassified

Ágata associada ao magmatismo do Cretáceo da Bacia do Paraná, sul do Brasil

et al. 2013

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Na porção sul do Brasil, especialmente na região denominada Distrito Mineiro de Salto do Jacuí (Rio Grande do Sul), localizam-se os maiores depósitos mundiais de ágata, associados às rochas vulcânicas cretáceas da Formação Serra Geral, Bacia do Paraná. A ágata é uma variedade de calcedônia com bandamento, onde as bandas se dispõem de forma concêntrica ou paralela no interior de cavidades denominadas geodos. Na região, ocorre a valorizada ágata denominada Umbu, de cor azul escura e com elevada microporosidade que a torna adequada para tingimento com corantes. Neste trabalho procurou-se caracterizar a ágata sob o ponto de vista químico, isotópico e petrográfico por meio de técnicas analíticas diversas. Verifica-se que a temperatura de formação das ágatas varia de 23° a 65°C com base em isótopos de oxigênio. Estas temperaturas estão relacionadas com vários parâ- metros, tais como o teor total de sílica, a presença de impurezas (como o Fe2O3), o teor de água na estrutura e a cristalinidade. As amostras analisadas caracterizam-se por diferenças marcantes nos teores de elementos maiores e traços, na temperatura de cristalização e na cristalinidade, o que indica que apesar de serem ágatas provenientes de uma mesma região, ocorrem variações no seu processo de cristalização. Isto resulta nas diferentes estruturas e colorações apresentadas pelas ágatas da região de Salto do Jacuí.

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Luminescence behaviour and Raman characterization of dendritic agate in the Dereyalak village (Eskişehir), Turkey

Cited by 14 publications

References 26 publications

Fabrication of core–shell nanocomposites with enhanced photocatalytic efficacy

Fabrication of core–shell nanocomposites with enhanced photocatalytic efficacy

Raman spectroscopy of minerals and mineral pigments in archaeometry

Ágata associada ao magmatismo do Cretáceo da Bacia do Paraná, sul do Brasil

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