Title : Tuning optical properties and thermal conductivity of a fluorescent polymer through the incorporation of magnetic nanoparticles
Abstract:
The development of polymer magnetic nanoparticle composites has garnered increasing interest due to their adjustable multifunctional properties and potential technological applications. In this study, we present the synthesis and detailed characterisation of a new poly(fluoromandelic acid) (PFMA) matrix incorporating various types of magnetic nanoparticles (MNPs). The effect of the magnetic filler type on the structural, optical, thermal, and magnetic properties of the resulting composites was systematically examined. These MNPs, synthesised via thermal decomposition, were also utilised to produce polymer composites with the novel fluorinated polymer PFMA. The thermal decomposition of MNPs was used to produce polymer composites with the newly developed fluorinated polymer PFMA. Three different sizes of magnetic nanoparticles (MNPs) were used to produce PFMA-based magnetic composites: small, medium, and large. The synthesis of these composites involved physically mixing PFMAs and MNPs at different proportions (10%, 30%, and 50%). The mixture was maintained at 130°C for 1 hour. During this process, the polymer melts, embedding the MNPs into its matrix.
Fourier transform infrared (FTIR) spectroscopy was used to analyse the structural features of the composites and to evaluate the interactions between the polymer matrix and the embedded magnetic nanoparticles. Fluorescence spectroscopy was employed to assess how nanoparticle incorporation influences the optical behaviour of the polymer, showing changes in emission intensity and spectral characteristics depending on the type of magnetic nanoparticle. The magnetic properties of the composites were studied using vibrating sample magnetometry (VSM), which provided insights into their magnetic response and confirmed the successful incorporation of magnetic nanoparticles into the polymer framework.
Thermal conductivity measurements indicated that both the presence and nature of the magnetic fillers significantly affect heat transfer within the polymer matrix. In these PFMA-based magnetic composites, thermal conductivity (λ) generally increases with temperature. Composites made with small-sized MNP show relatively stable λ values across different temperatures. Specifically, in magnetic PFMA composites with 50% small-sized MNP, λ increases by up to 185% during polymer formation. For composites with larger MNP, thermal conductivity rises with higher MNP content: adding 10% MNP doubles λ, while 30% MNP results in nearly an 80% increase. Filler contents of 10% and 30% yield only slight improvements, whereas incorporating 50% MNP boosts λ by 136%. Overall, these magnetic composites do not show significant changes in λ with temperature.
Overall, these findings underscore the versatility of PFMA as a host matrix for magnetic nanoparticles and suggest that careful selection of magnetic filler characteristics can tune composite properties, making these materials promising candidates for multifunctional applications.
Acknowledgement: This research is carried out and financed within the framework of the second Swiss Contribution MAPS project code: F-RO-CH-2024-0041 and MAPS project No. 230110.
