Faculty Publications

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Author: search.filters.author.Kattimani, S.Subject: search.filters.subject.Dielectric properties of solids

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    Effect of BTO piezoceramic on the mechanical and dielectric properties of 3D-printed PLA.BTO functional polymer composite
    (Springer Nature, 2025) Senthil Murugan, S.; Kattimani, S.; Saminathan, R.
    The development of polymer composite materials for additive manufacturing is critical for advancing industrial applications. This study enhances the functional performance of poly-lactic acid (PLA) by incorporating barium titanate (BTO/BaTiO?) particles. Uniform dispersion of BTO within the PLA matrix was achieved, and filaments were fabricated using fused deposition modelling (FDM) with a 60% infill rate, adhering to ASTM standards. The influence of BTO fillers on the mechanical and dielectric properties of PLA.BTO composites were analysed and compared to pure PLA. FESEM microstructural analysis confirmed distinct layering, defect-free deposition, and uniform BTO distribution. Mechanical testing revealed notable improvements, including increases in tensile strength (16.4%), flexural strength (17.1%), shore hardness (4.7%), impact strength (17.7%), and drop-weight energy absorption for a 5 mm plate (26%), attributed to enhanced interfacial bonding and reduced void formation. The dielectric properties exhibited significant enhancements, with a 12.9% increase in dielectric strength, a 15% higher dielectric constant, an 8% greater breakdown strength, and a 21.74% rise in electrical susceptibility. Furthermore, reductions in loss tangent (19.1%), AC conductivity (7.8%), and dielectric loss (6.8%) demonstrated the material’s ability to store and withstand electric fields efficiently. Ferroelectric analysis revealed improved remanence, coercivity, and polarization, underscoring the composite’s potential as a piezoelectric material. These findings highlight the suitability of PLA.BTO composites for energy storage devices, sensors, and biodegradable functional applications, offering a promising balance of mechanical durability and superior dielectric performance. © Qatar University and Springer Nature Switzerland AG 2025.
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    Investigation of dielectric properties and shore hardness of 3D-printed PLA core sandwich disc with functional ceramics surface cladding
    (KeAi Publishing Communications Ltd., 2025) Senthil Murugan, S.S.; Kattimani, S.; Bharadwaj, N.
    Poly-lactic acid (PLA), a popular biodegradable polymer for 3D printing, has limited dielectric strength and surface hardness, restricting its use in advanced electronic and structural applications. Existing enhancement methods are often complex or yield inconsistent results. Therefore, a straightforward and scalable approach is necessary to enhance the properties of 3D-printed PLA. This study aims to explore the enhancement of the dielectric and surface hardness of printed PLA discs through surface cladding using nano-functional ceramics and graphene for next-generation multifunctional applications. PLA discs were fabricated via Fused Deposition Modelling (FDM) and subsequently cladded using hand layup with Araldite resin as a binder. Cladding materials included cobalt ferrite (CF), barium titanate (BTO), and graphene (Gr), individually and in combinations. Dielectric properties—capacitance, impedance, dielectric constant, dielectric loss, dissipation factor, and AC conductivity—were analyzed using an impedance analyzer, while surface hardness was measured using a Shore-D durometer. Results revealed that cladding led to uniform particle dispersion with effective surface bonding, improved dielectric performance, and significantly enhanced surface hardness. The CF + BTO + Gr combination exhibited superior dielectric behaviour, balancing high polarization with low energy dissipation, while BTO contributed to an enhanced dielectric constant and graphene improved charge transfer. All cladded samples showed frequency-dependent dielectric responses, with stability at higher frequencies. The highest surface hardness was achieved with CF + BTO, attributed to rigid, uniform reinforcement. © 2025 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltdé This is an open access article under the CC BY-NC-ND license. http://creativecommons.org/licenses/by-nc-nd/4.0/