Deakin University, Institute for Frontier Materials (IFM), Geelong, Australia.
Department of Materials Engineering, Defence Institute of Advanced Technology, Ministry of Defence, Girinagar, 411025 Pune, India.
Sci Rep. 2016 Jul 20;6:29917. doi: 10.1038/srep29917.
Inorganic/organic nanofillers have been extensively exploited to impart thermal stability to polymer nanocomposite via various strategies that can endure structural changes when exposed a wide range of thermal environment during their application. In this abstraction, we have utilized temperature assisted in-situ small angle X-ray scattering (SAXS) to examine the structural orientation distribution of inorganic/organic nanofiller octa phenyl substituted polyhedral oligomeric silsesquioxane (Ph-POSS) in Polycarbonate (PC) matrix from ambient temperature to 180 °C. A constant interval of 30 °C with the heating rate of 3 °C/min was utilized to guise the temperature below and above the glass transition temperature of PC followed by thermal gravimetric, HRTEM, FESEM and hydrophobic analysis at ambient temperature. The HRTEM images of Ph-POSS nano unit demonstrated hyperrectangular structure, while FESEM image of the developed nano composite rendered separated phase containing flocculated and overlapped stacking of POSS units in the PC matrix. The phase separation in polymer nanocomposite was further substantiated by thermodynamic interaction parameter (χ) and mixing energy (Emix) gleaned via Accelrys Materials studio. The SAXS spectra has demonstrated duplex peak at higher scattering vector region, postulated as a primary and secondary segregated POSS domain and followed by abundance of secondary peak with temperature augmentation.
无机/有机纳米填料已被广泛用于通过各种策略赋予聚合物纳米复合材料热稳定性，这些策略可以在应用过程中暴露于广泛的热环境时承受结构变化。在本摘要中，我们利用温度辅助原位小角 X 射线散射（SAXS）研究了无机/有机纳米填料八苯基取代的多面体低聚倍半硅氧烷（Ph-POSS）在聚碳酸酯（PC）基质中的结构取向分布，温度范围从环境温度到 180°C。采用 3°C/min 的升温速率，以 30°C 的恒定间隔，在 PC 的玻璃化转变温度以下和以上进行加热，随后在环境温度下进行热重分析、高分辨率透射电子显微镜（HRTEM）、场发射扫描电子显微镜（FESEM）和疏水性分析。Ph-POSS 纳米单元的 HRTEM 图像显示出超矩形结构，而开发的纳米复合材料的 FESEM 图像呈现出分离相，其中 POSS 单元在 PC 基质中絮凝和重叠堆叠。通过 Accelrys Materials studio 获得的热力学相互作用参数（χ）和混合能（Emix）进一步证实了聚合物纳米复合材料中的相分离。SAXS 谱在较高散射矢量区域显示出双峰值，假定为初级和次级隔离的 POSS 域，随后随着温度升高，次级峰值增多。
