Thermal and morphological characterization of highly porous nanocomposites for possible application in potassium controlled release

Autor: Carlos Roberto Ferreira Júnior, Márcia R. de Moura, Fauze A. Aouada, Fabrício Nunes Tanaka, Adriel Bortolin
Přispěvatelé: Universidade Estadual Paulista (Unesp), Universidade Federal de São Carlos (UFSCar)
Rok vydání: 2017
Předmět:
Zdroj: Scopus
Repositório Institucional da UNESP
Universidade Estadual Paulista (UNESP)
instacron:UNESP
ISSN: 1588-2926
1388-6150
DOI: 10.1007/s10973-017-6755-9
Popis: Made available in DSpace on 2018-12-11T17:34:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The use of fertilizer and water availability are essential factors limiting the agricultural production. The controlled release technology is very promising because it allows the maintenance of fertilizer concentrations within an ideal range avoiding inefficiency and toxicity problems, minimizing the environmental impacts and improving their efficiency. In this context, the nanostructured hydrogels appear as a possible carrier vehicle for these controlled release systems due to their inherent properties, such as biodegradability, low toxicity, and cost, rapid absorption and desorption controlled capacity of water and solutes. In this work, we performed the synthesis of nanostructured hydrogels based on poly(methacrylic acid) (PMAA)/Cloisite-Na+ via free radical polymerization. SEM images indicated a similarity in the basic structure of all nanocomposites. The porous diameter of the hydrogels increased with increasing of nanoclay content. EDS analysis showed the ions belonging to nanoclay present in the nanocomposites, confirming the formation of true nanocomposites. TG–DTG and DSC techniques confirmed an improvement in the thermal stability of nanocomposites caused by the addition of nanoclay. For instance, the degradation initial temperature of the hydrogel was increased from 198.5 to 203.5 °C, and inversely, the degradation rate of the 2° thermal event was decreased from 0.694 to 0.472% min °C−1, when the nanoclay was increased from 0 to 20 mass/%. Moreover, the controlled release investigation showed an improvement in the release time and quantity of the fertilizer released with nanoclay content. This result is very required for this specific application. Grupo de Compósitos e Nanocompósitos Híbridos (GCNH) Programa de Pós-Graduação em Ciência dos Materiais School of Engineering São Paulo State University (Unesp) Departamento de Química Universidade Federal de São Carlos (UFSCar) Grupo de Compósitos e Nanocompósitos Híbridos (GCNH) Programa de Pós-Graduação em Ciência dos Materiais School of Engineering São Paulo State University (Unesp)
Databáze: OpenAIRE
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