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Semiconducting Nanocomposites Based on Conjugated Polymers and Multifunctional Janus Nanoparticles as Novel Type of Filler
Project status: Ended
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       Stage I/2022

       During the first activity (A1.1), two categories of spherical nanoparticles NPs were synthesized: polystyrene nanoparticles NPs1 and polystyrene-co-tert-butylacrylate nanoparticles NPs2. The seed nanoparticles NPs1 and NPs2 served as the foundation for creating two analogous series of Janus nanoparticles JNPs in task A1.2. By adjusting the quantity of TSPM, Janus nanoparticles with varied lobe diameters were synthesized. These JNP-type nanoparticles consist of two chemically distinct spherical lobes: a polystyrene seed lobe and a polar TSPM lobe, which enhances the nanoparticles' dispersibility in water.

       The series of JNPs nanoparticles were employed in task A1.3 to produce semiconductor nanoparticles with adjustable conductivities, achieved by attaching a conductive polymer to the non-polar lobe. By modifying the amount of polyaniline or polypyrrole, we obtained semiconductive Janus nanoparticles with diverse conductivities. Notably, during this task, we established the project's website (WP5) and initiated the scientific coordination of activities in stage I/2022 (WP6).

       Within the scope of task A1.4, an assessment of the thermal, dielectric, and electrical properties of NPs seeds, Janus JNPs, and semiconductive nanoparticles was conducted.

 

       Stage II/2023

       Following the activity A2.1, different types of polymers were selected as matrices for integrating Janus semiconductor nanoparticles: 1) Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate - PEDOT:PSS, 2) a series of amphiphilic conjugated polymers based on a polyaniline derivative - PANs, and 3) poly(vinyl alcohol) (PVA) and glycerol - PVA-Gly. All types of conjugated polymers exhibit water dispersibility. In task A2.2., the polymer matrices underwent characterization using specific physico-chemical methods. Special emphasis was placed on evaluating dielectric properties to assess the electrical conductivity of the polymer matrices and to understand the impact of the hydrophobic polyaniline chain on macromolecular chain interactions.

       Considering electrical properties and water dispersibility, activity A3.1. focused on optimizing the preparation process of semiconductor nanocomposites. The goal was to achieve a uniform distribution of nanoparticles in the polymer matrix and enhance the electrical conductivity of the final product. Series of nanocomposites (based on PEDOT:PSS, PANs-30 and PVA-Gly matrices) with varying concentrations of semiconductive Janus nanoparticles were prepared.

       The physico-chemical characterization of the PANs-30/JNPs, PEDOT:PSS/JNPs and PVA-Gly/JNPs nanocomposite series took place in task A3.2. Finally (A4.1.), the molecular dynamics of the macromolecular chains in the nanocomposites were assessed. The introduction of semiconductor nanoparticles into the polymer matrix resulted in spacing the macromolecular chains within the composites, consequently reducing intermolecular interactions.

 

       Stage III/2024

       The direct current conductivity of the nanocomposites as a function of temperature and the alternating current conductivity as a function of temperature and frequency for the JNPs-based nanocomposites containing different levels of semiconductive JNPs were analysed. Through this analysis, we gained insights into the charge conduction mechanism, revealing the transport processes within JNPs-based nanocomposites. Additionally, we assessed the conductivity of these nanocomposites when designed to function as variable resistors.

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