title: Synthesis and Characterizations of Novel Ca-Mg-Ti-Fe-Oxides Based Ceramic Nanocrystals and Flexible Film of Polydimethylsiloxane Composite with Improved Mechanical and Dielectric Properties for Sensors.
abstract: Armalcolite, a rare ceramic mineral and normally found in the lunar earth, was synthesized by solid-state step-sintering. The in situ phase-changed novel ceramic nanocrystals of Ca-Mg-Ti-Fe based oxide (CMTFOx), their chemical reactions and bonding with polydimethylsiloxane (PDMS) were determined by X-ray diffraction, infrared spectroscopy, and microscopy. Water absorption of all the CMTFOx was high. The lower dielectric loss tangent value (0.155 at 1 MHz) was obtained for the ceramic sintered at 1050 °C (S1050) and it became lowest for the S1050/PDMS nanocomposite (0.002 at 1 MHz) film, which was made by spin coating at 3000 rpm. The excellent flexibility (static modulus ≈ 0.27 MPa and elongation > 90%), viscoelastic property (tanδ = E″/E': 0.225) and glass transition temperature (Tg: -58.5 °C) were obtained for S1050/PDMS film. Parallel-plate capacitive and flexible resistive humidity sensors have been developed successfully. The best sensing performance of the present S1050 (3000%) and its flexible S1050/PDMS composite film (306%) based humidity sensors was found to be at 100 Hz, better than conventional materials.
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. ashisbidyarthi@gmail.com.
authors.forename: Ashis
authors.initials: A
authors.lastname: Tripathy
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. prsumit@gmail.com.
authors.forename: Sumit
authors.initials: S
authors.lastname: Pramanik
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. ayanbabu@gmail.com.
authors.forename: Ayan
authors.initials: A
authors.lastname: Manna
authors.affiliation: Department of Paediatric Dentistry & Orthodontics, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia. nabilafarhana.shah@gmail.com.
authors.forename: Nabila Farhana Azrin
authors.initials: NF
authors.lastname: Shah
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. hanie_nadia@um.edu.my.
authors.forename: Hanie Nadia
authors.initials: HN
authors.lastname: Shasmin
authors.affiliation: Department of Paediatric Dentistry & Orthodontics, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia. zamrir@um.edu.my.
authors.forename: Zamri
authors.initials: Z
authors.lastname: Radzi
authors.affiliation: Centre for Applied Biomechanics, Department of Biomedical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. prsumit@um.edu.my.
authors.forename: Noor Azuan
authors.initials: NA
authors.lastname: Abu Osman
keywords: X-ray diffraction; dynamic mechanical property; flexibility; nanocomposite; polymer; sensitivity; sintering