In this study, the epoxy microcapsules with the nanosilica (0, 1, 2, and 3 wt %)—urea formaldehyde composite shell were synthesized and then characterized by optical microscope (OM), field emission scanning electron microscope (FESEM), Fourier‐transform infrared spectroscopy (FT‐IR), and thermogravimetric analysis. According to the OM analysis, the without nanosilica microcapsules had the semitransparent structures and equal size distributions. Also, the formation of the microcapsule clusters and rupturing microcapsules in the sample containing 3 wt % nanosilica were observed by OM method. The FESEM analysis showed that without nanosilica, microcapsules had a smooth surface, whereas by increasing the percentage of nanosilica up to 2 wt %, the surface roughness was enhanced. It was also observed that on the surface of the microcapsules without nanosilica, two size ranges of the submicrocapsules with the average diameters of 1.12 μm and 208 nm were formed. By adding 1 wt % nanosilica, three size ranges of submicrocapsules were formed, with the average size of 2.63 μm, 824 and 179 nm. The interesting phenomena in the microcapsules containing 2 and 3 wt % nanosilica were the packing submicrocapsules with the polymeric shell and the formation of the microcapsule clusters, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48580.

中文翻译：

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纳米二氧化硅-脲甲醛复合壳的微囊化环氧树脂

在这项研究中，合成了具有纳米二氧化硅（0、1、2和3 wt％）-脲甲醛复合壳的环氧微囊，然后通过光学显微镜（OM），场发射扫描电子显微镜（FESEM），傅里叶-变换红外光谱（FT‐IR）和热重分析。根据OM分析，没有纳米二氧化硅的微胶囊具有半透明的结构和相等的尺寸分布。另外，通过OM法观察到在包含3重量％的纳米二氧化硅的样品中微胶囊簇的形成和微胶囊的破裂。FESEM分析表明，在没有纳米二氧化硅的情况下，微胶囊具有光滑的表面，而通过将纳米二氧化硅的百分比增加至高达2wt％，表面粗糙度得以提高。还观察到在没有纳米二氧化硅的微囊的表面上，形成了两个尺寸范围的平均直径为1.12μm和208nm的亚微囊。通过添加1wt％的纳米二氧化硅，形成了三个尺寸范围的亚微囊，其平均尺寸为2.63μm，824和179nm。在包含2和3wt％的纳米二氧化硅的微胶囊中有趣的现象是具有聚合物壳的填充亚微胶囊和微胶囊簇的形成。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学 在包含2和3wt％的纳米二氧化硅的微胶囊中有趣的现象是具有聚合物壳的填充亚微胶囊和微胶囊簇的形成。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学 在含有2和3重量％的纳米二氧化硅的微囊中有趣的现象是具有聚合物壳的填充亚微囊和微囊簇的形成。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学2020，137，48580。