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 | Acesso ao texto completo restrito à biblioteca da Embrapa Pecuária Sudeste. Para informações adicionais entre em contato com cppse.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Pecuária Sudeste. |
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Data corrente: |
26/07/2012 |
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Data da última atualização: |
17/02/2023 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
PEREIRA, E. I.; MINUSSI, F. B.; CRUZ, C. C. T. da; BERNARDI, A. C. de C. |
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Afiliação: |
ELAINE I. PEREIRA, UFSCAR/SÃO CARLOS, SP; FERNANDO B. MINUSSI, UFSCAR/SÃO CARLOS, SP; CAMILA C. T. DA CRUZ, UFSCAR/SÃO CARLOS, SP; ALBERTO CARLOS DE CAMPOS BERNARDI, CPPSE. |
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Título: |
Urea-montmorillonite-extruded nanocomposites: a novel slow-release material. |
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Ano de publicação: |
2012 |
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Fonte/Imprenta: |
Journal of Agricultural and Food Chemistry, v. 60, p. 5267-5272, 2012. |
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DOI: |
10.1021/jf3001229 |
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Idioma: |
Inglês |
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Conteúdo: |
The present study describes the preparation and characterization of a novel urea slow-release nanocomposite, based on urea intercalation into montmorillonite clay by an extrusion process at room temperature. Nanocomposites with urea contents ranging from 50 to 80 wt % were successfully produced and characterized. Analyses by XRD, DTA, and SEM-EDX con?rmed the e?ectiveness of this simple process to exfoliate the clay lamellae into the urea matrix, forming a product that can be classi?ed as a nanocomposite, due to the exfoliation degree attained. Diametral compression tests showed that the samples were very deformable, and the release rate of active components in water showed that the nanocomposite showed a slow release behavior for urea dissolution, even in low montmorillonite amounts (20% in weight). |
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Palavras-Chave: |
Fertilizer; Intercalation. |
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Thesaurus Nal: |
extrusion; montmorillonite; urea. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 01483naa a2200229 a 4500
001 1929515
005 2023-02-17
008 2012 bl uuuu u00u1 u #d
024 7 $a10.1021/jf3001229$2DOI
100 1 $aPEREIRA, E. I.
245 $aUrea-montmorillonite-extruded nanocomposites$ba novel slow-release material.$h[electronic resource]
260 $c2012
520 $aThe present study describes the preparation and characterization of a novel urea slow-release nanocomposite, based on urea intercalation into montmorillonite clay by an extrusion process at room temperature. Nanocomposites with urea contents ranging from 50 to 80 wt % were successfully produced and characterized. Analyses by XRD, DTA, and SEM-EDX con?rmed the e?ectiveness of this simple process to exfoliate the clay lamellae into the urea matrix, forming a product that can be classi?ed as a nanocomposite, due to the exfoliation degree attained. Diametral compression tests showed that the samples were very deformable, and the release rate of active components in water showed that the nanocomposite showed a slow release behavior for urea dissolution, even in low montmorillonite amounts (20% in weight).
650 $aextrusion
650 $amontmorillonite
650 $aurea
653 $aFertilizer
653 $aIntercalation
700 1 $aMINUSSI, F. B.
700 1 $aCRUZ, C. C. T. da
700 1 $aBERNARDI, A. C. de C.
773 $tJournal of Agricultural and Food Chemistry$gv. 60, p. 5267-5272, 2012.
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Embrapa Pecuária Sudeste (CPPSE) |
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Registro Completo
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Biblioteca(s): |
Embrapa Solos. |
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Data corrente: |
22/11/2002 |
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Data da última atualização: |
11/05/2022 |
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Autoria: |
PALMIERI, F. |
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Afiliação: |
FRANCESCO PALMIERI, CNPS. |
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Título: |
A study of a climosequence of soils derived from volcanic rock parent material in Santa Catarina and Rio Grande do Sul States, Brazil. |
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Ano de publicação: |
1986 |
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Fonte/Imprenta: |
1986. |
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Páginas: |
259 f. |
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Idioma: |
Inglês |
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Notas: |
Tese (Doutorado) - Purdue University, West Lafayette. |
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Conteúdo: |
Ten soils formed from basic volcanic rocks were studied on a 450 km climosequence transect in Santa Catarina and Rio Grande do Sul States, Brazil, to learn how soil properties vary with climate and to provide a data base for the developing Brazilian soil classification system. From east to west the altitude drops from 1250 m to 270 m, the annual temperature increases from 14.1(DEGREES)C to 19.3(DEGREES)C, and the annual precipitation decreases from 2460 mm to 1850 mm. The soils were in the Cambisol, Terra Bruna Estruturada (a new class), Brown Latosol, Terra Roxa Estruturada, and Dusky Red Latosol soil classes of the Brazilian soil classification and in the Dystrochrept, Haplumbrept, Paleudult, Haplohumox and Haplorthox great groups of the U.S. Soil Taxonomy. As soil sites get warmer and drier, kaolinite and hematite contents increase, halloysite and goethite contents decrease, the crystal size of kaolin minerals (kaolinite and 0.7 nm halloysite) increases, soil color changes from brown to dusky red, soil structure changes from well developed blocky to ultra fine granular (massive-like), and surface area and soil swelling decrease. The soil materials mainly had isotic plasmic fabric (isotropic) and had few or no argillans visible in thin section. Gibbsite and halloysite form immediately adjacent to each other in the weathered basaltic rocks. Maghemite occurred in 2.5YR and redder soils. Upward in the solum organic carbon and goethite contents increase, hematite decreases, the soil color becomes yellower and crystal size of kaolin minerals increases. These Fe-rich soils sorbed large amounts of phosphate. Acccording to prevailing ideas, tropical and subtropical soils composed mainly of kaolin and iron-oxide minerals have low surface activity and low shrink-swell potential. These soils shrink enough to open subsoil cracks 10 mm wide in the summer and have a moderately high swelling index (COLE = 0.042). Typically kaolin minerals are described as having 6 to 43 m('2) g('-1) surface area but in these soils it is about 300 m('2) g('-1). Surface area was inversely related to the mean crystallite dimension of kaolin minerals and directly related to COLE values and to phosphate sorption. Soil shear strength measured by the Swedish fall-cone increased as the soil structure changed from ultra fine granular (massive-like) to blocky structure and with increasing halloysite and goethite contents. MenosTen soils formed from basic volcanic rocks were studied on a 450 km climosequence transect in Santa Catarina and Rio Grande do Sul States, Brazil, to learn how soil properties vary with climate and to provide a data base for the developing Brazilian soil classification system. From east to west the altitude drops from 1250 m to 270 m, the annual temperature increases from 14.1(DEGREES)C to 19.3(DEGREES)C, and the annual precipitation decreases from 2460 mm to 1850 mm. The soils were in the Cambisol, Terra Bruna Estruturada (a new class), Brown Latosol, Terra Roxa Estruturada, and Dusky Red Latosol soil classes of the Brazilian soil classification and in the Dystrochrept, Haplumbrept, Paleudult, Haplohumox and Haplorthox great groups of the U.S. Soil Taxonomy. As soil sites get warmer and drier, kaolinite and hematite contents increase, halloysite and goethite contents decrease, the crystal size of kaolin minerals (kaolinite and 0.7 nm halloysite) increases, soil color changes from brown to dusky red, soil structure changes from well developed blocky to ultra fine granular (massive-like), and surface area and soil swelling decrease. The soil materials mainly had isotic plasmic fabric (isotropic) and had few or no argillans visible in thin section. Gibbsite and halloysite form immediately adjacent to each other in the weathered basaltic rocks. Maghemite occurred in 2.5YR and redder soils. Upward in the solum organic carbon and goethite contents increase, hematite decreases, th... Mostrar Tudo |
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Palavras-Chave: |
Classificação; Propriedade; Rio Grande do Sul; Santa Catarina; Solos; Vulcão. |
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Thesagro: |
Classificação do Solo; Mineralogia; Rocha; Solo. |
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Thesaurus NAL: |
Soil. |
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Categoria do assunto: |
--
P Recursos Naturais, Ciências Ambientais e da Terra |
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Marc: |
LEADER 03168nam a2200265 a 4500
001 1330863
005 2022-05-11
008 1986 bl uuuu m 00u1 u #d
100 1 $aPALMIERI, F.
245 $aA study of a climosequence of soils derived from volcanic rock parent material in Santa Catarina and Rio Grande do Sul States, Brazil.
260 $a1986.$c1986
300 $a259 f.
500 $aTese (Doutorado) - Purdue University, West Lafayette.
520 $aTen soils formed from basic volcanic rocks were studied on a 450 km climosequence transect in Santa Catarina and Rio Grande do Sul States, Brazil, to learn how soil properties vary with climate and to provide a data base for the developing Brazilian soil classification system. From east to west the altitude drops from 1250 m to 270 m, the annual temperature increases from 14.1(DEGREES)C to 19.3(DEGREES)C, and the annual precipitation decreases from 2460 mm to 1850 mm. The soils were in the Cambisol, Terra Bruna Estruturada (a new class), Brown Latosol, Terra Roxa Estruturada, and Dusky Red Latosol soil classes of the Brazilian soil classification and in the Dystrochrept, Haplumbrept, Paleudult, Haplohumox and Haplorthox great groups of the U.S. Soil Taxonomy. As soil sites get warmer and drier, kaolinite and hematite contents increase, halloysite and goethite contents decrease, the crystal size of kaolin minerals (kaolinite and 0.7 nm halloysite) increases, soil color changes from brown to dusky red, soil structure changes from well developed blocky to ultra fine granular (massive-like), and surface area and soil swelling decrease. The soil materials mainly had isotic plasmic fabric (isotropic) and had few or no argillans visible in thin section. Gibbsite and halloysite form immediately adjacent to each other in the weathered basaltic rocks. Maghemite occurred in 2.5YR and redder soils. Upward in the solum organic carbon and goethite contents increase, hematite decreases, the soil color becomes yellower and crystal size of kaolin minerals increases. These Fe-rich soils sorbed large amounts of phosphate. Acccording to prevailing ideas, tropical and subtropical soils composed mainly of kaolin and iron-oxide minerals have low surface activity and low shrink-swell potential. These soils shrink enough to open subsoil cracks 10 mm wide in the summer and have a moderately high swelling index (COLE = 0.042). Typically kaolin minerals are described as having 6 to 43 m('2) g('-1) surface area but in these soils it is about 300 m('2) g('-1). Surface area was inversely related to the mean crystallite dimension of kaolin minerals and directly related to COLE values and to phosphate sorption. Soil shear strength measured by the Swedish fall-cone increased as the soil structure changed from ultra fine granular (massive-like) to blocky structure and with increasing halloysite and goethite contents.
650 $aSoil
650 $aClassificação do Solo
650 $aMineralogia
650 $aRocha
650 $aSolo
653 $aClassificação
653 $aPropriedade
653 $aRio Grande do Sul
653 $aSanta Catarina
653 $aSolos
653 $aVulcão
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