• MUSTAFA OKUTAN

Articles written in Bulletin of Materials Science

• Effect of borax additive on the dielectric response of polypyrrole

The main aim of this study is to produce added polypyrrole (PPy) borax compositeswith high dielectric properties for technological applications. For this purpose, PPy–borax compositeswith different borax concentrations varying from 10 to 50 wt% have been prepared. To reveal their structural and morphological attributes, the composites have been characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. The real and imaginary parts of complex dielectric function, the imaginary component of complex electrical modulus and ac conductivity have been investigated at room temperature as a function of frequency in the range 100 Hz–15 MHz. It has been found that addition of borax increases the dielectric constant of pure PPy. In this respect, PPy–borax composites with the highest dielectric constant at low frequency may be utilized in charge storing devices. On the other hand, the dielectric loss is also very high in low-frequency region for the composites with high borax content. Exploiting this property, the material may also be used in decoupling capacitor applications. The relaxation mechanisms of the samples have also been determined as non-Debye type. The Nyquist curves of the samples have been analysed for calculating the grain and grain boundary resistance andcapacitance values. In conclusion, borax has a promising potential to be used as a cheap and effective filler for improving the dielectric properties of PPy polymer.Keywords. Polypyrrole; borax; dielectric properties; Nyquist plot; non-Debye-type relaxation; Cole–Cole equation.

• Dielectric properties of boron-doped PDMS composites

Polydimethylsiloxane (PDMS) was studied with different concentrations of boron in the structure of a polymer composite. Dielectric characterization of the prepared composite samples was analysed by dielectric spectroscopy. According to the outcomes of dielectric characterization, the increase in the B-doping ratio caused an increase in dielectric constant. Also, the lowest value of relaxation time was attained by 10% boron-doped PDMS. Besides, the studies of ${\alpha}$-relation, relation time values and imaginary part of permittivity indicated that 10% boron-doped PDMS is found to be an optimized amount for a proper composite. Optimization of a tailored boron-doped polymer composite was realized and attained by dielectric spectroscopy throughout our work.

• # Bulletin of Materials Science

Volume 45, 2022
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020