Exploring the Electromagnetic Characteristics of Polyimide/TiO2 Hybrid Films and Their Interface-Dependent Behavior

Limited knowledge of the interfacial region - which greatly contributes to the dielectric response - can limit the development of stable polymer nanocomposites for complex electrical and shielding applications. This work developed polyimide/titanium dioxide (TiO2) hybrid layers from a polymer acid precursor, using coated (3-aminopropyl) triethoxysilane (APTES) modified TiO2 nanoparticles, followed by thermal imidization. We analyzed the interfacial region using high resolution transmission electron microscope (HR TEM) and x ray ultraviolet (UV) spectroscopy (XPS) to assess both the chemistry and architecture. The film's electric responses were characterized using wide-band electromagnetic imaging (10 Hz to 1 Mhz) with distributed network analysis in the x bands (8.2 to 12.4 GHz). With the experimental observations contextualized via comparisons to the Electricity Behavior of Chemicals (Kaggle, 2022) dataset with dielectric values for 1,000 + inorganic materials, we reported dielectric values for functionalized particles at a 35% realized improvement in dielectric properties and a large reduction (0.008 versus 0.023 at 1 kHz) in tangent loss for functionalized films when compared to the control films. These observations support the predictions made by the dataset with high-κ oxide. There was also a shift in the EMI shielding mechanism from reflection (approximately - 15 dB) to absorption (around -22dB), as dispersion and contact liaison increased due to covalent bonding. These results indicate that face engineering is the primary factor affecting radiation performance. This enables lightweight, powerful parts for future modular devices, and reduced EMI.