Abstract Clay-polymer composites represent the possibility to stabilize, protect volatile and easily oxidized compounds such as essential oils. Thus, the aim of this study was to develop an eco-friendly formulation based on bentonite/PVP nanocomposites to incorporate Syzygium aromaticum essential oil (SAEO) in for controlling Aedes aegypti larvae. The bentonite/PVP nanocomposites were prepared with different ratios 1:2, 1:1, 2:1 in both absence (INano) or presence of SAEO (NanoSAEO), and evaluated by X-ray diffraction (XRD), small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR). Finally, larvicidal activity was performed. XRD indicated an intercalated structure because of the displacement of reflections at low angle range and an increase in INano interlayer space (d). After SAEO incorporation, the interlayer space (d) did not changed, therefore suggesting that SAEO may be associated to the nanocomposite-intercalated layers. SAXS also demonstrated the composite intercalated structure that in presence of SAEO induced a reflection displacement and change in the curve profile suggesting a structure transition to accommodate SAEO. This structure transition after SAEO incorporation was enough to shift the nanocomposite endothermic peak to lower temperatures (Tpeak = 68 °C) in DSC analysis. NanoSAEO demonstrated a LC50 of 27.34 ppm, while eugenol and SAEO presented 48.19 ppm and 40.74 ppm, respectively. Furthermore, SAEO incorporated in the nanocomposite was not harmful to non-target organisms, being not toxic up to 1000 ppm. Thus, bentonite/PVP nanocomposites containing SAEO is a promising formulation for controlling Aedes aegypti larvae.

中文翻译：

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富含丁香精油的粘土/PVP 纳米复合材料是一种针对埃及伊蚊幼虫的安全配方

摘要 粘土聚合物复合材料代表了稳定、保护挥发性和易氧化化合物（如精油）的可能性。因此，本研究的目的是开发一种基于膨润土/PVP 纳米复合材料的环保配方，将香蒲精油 (SAEO) 用于控制埃及伊蚊幼虫。在不存在（INano）或存在SAEO（NanoSAEO）的情况下以1:2、1:1、2:1的不同比例制备膨润土/PVP纳米复合材料，并通过X射线衍射（XRD）、小角X-射线散射 (SAXS)、差示扫描量热法 (DSC)、扫描电子显微镜 (SEM) 和傅里叶变换红外光谱 (FTIR)。最后，进行杀幼虫活性。由于低角度范围内的反射位移和 INano 层间空间的增加（d），XRD 表明存在插层结构。SAEO 掺入后，层间空间（d）没有改变，因此表明 SAEO 可能与纳米复合材料插层相关。SAXS 还证明了复合插层结构，在存在 SAEO 时会引起反射位移和曲线轮廓的变化，表明结构转变以适应 SAEO。在 DSC 分析中，SAEO 掺入后的这种结构转变足以将纳米复合材料的吸热峰转移到较低的温度 (Tpeak = 68 °C)。NanoSAEO 的 LC50 为 27.34 ppm，而丁香酚和 SAEO 分别为 48.19 ppm 和 40.74 ppm。此外，纳米复合材料中掺入的 SAEO 对非目标生物无害，在 1000 ppm 以下无毒。因此，含有SAEO的膨润土/PVP纳米复合材料是控制埃及伊蚊幼虫的有前途的配方。