Infrared analysis, thermogravimetric analysis, and light scattering of grafted PCL-b-POEGMA on SiO2 NPs

Attachment of grafted PCL-b-POEGMA on SiO2 NPs was confirmed via thermogravimetric analysis (TGA) decomposition events in comparison to the linear free polymer analogue. IR (infrared analysis) was performed and it showed an increase in carbonyl and CH2 content, with a decrease in hydroxyl content as subsequent blocks were grafted from the NPs. Light scattering was used for confirmation of size changes in solution by Rh and/or Rg values in various solvents. Light scattering analysis also included size changes upon hydrocarbon uptake.通过与线性游离聚合物类似物对比热重分析（thermogravimetric analysis，TGA）的分解特征，证实了SiO₂纳米颗粒（SiO₂ NPs）上接枝的聚己内酯-b-聚寡聚乙二醇甲醚丙烯酸酯（PCL-b-POEGMA）的接枝行为。采用红外分析（infrared analysis，IR）进行表征后发现：随着纳米颗粒表面接枝后续嵌段，羰基与亚甲基（CH₂）的含量上升，而羟基含量出现下降。借助光散射技术，通过不同溶剂中的流体力学半径（hydrodynamic radius，Rh）与/或回转半径（radius of gyration，Rg）数值，验证了其在溶液中的尺寸变化。此外，光散射分析还涵盖了烃类摄取过程中的尺寸变化特征。