Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, CEP: 13565-905, São Carlos, SP, Brazil.
J Agric Food Chem. 2012 May 30;60(21):5267-72. doi: 10.1021/jf3001229. Epub 2012 May 21.
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 confirmed the effectiveness of this simple process to exfoliate the clay lamellae into the urea matrix, forming a product that can be classified 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).
本研究描述了一种新型尿素缓释纳米复合材料的制备和表征，该材料是通过在室温下的挤出工艺将尿素嵌入蒙脱土粘土中制备的。成功制备并表征了尿素含量在 50 至 80wt%之间的纳米复合材料。XRD、DTA 和 SEM-EDX 分析证实了这种简单工艺的有效性，它可以将粘土薄片剥离到尿素基质中，形成一种可以被归类为纳米复合材料的产物，因为达到了剥离程度。直径压缩测试表明，样品具有很好的可变形性，在水中的活性成分释放率表明，纳米复合材料在低蒙脱土含量（20wt%）下对尿素溶解具有缓释行为。
