The effect of dispersion technique, reduction method, and the amount of silver nanoparticles on the properties of composite polyacrylonitrile nanofiber containing silver nanoparticles is analyzed using differential scanning calorimetry, scanning electron microscopy, electrical conductivity, tensile testing, X-ray diffraction, and antimicrobial efficiency measurements. Composite nanofibers reduced by hydrazine hydroxide result in smaller diameter, higher electrical conductivity, higher breaking strength, higher cyclization enthalpy than the samples reduced by xenon arc method. Reduction process results in smaller diameter and higher breaking strength than those of non-reduced nanofiber web containing AgNO3 nanoparticles. Dispersion by ultrasonic homogenizer/bath provides higher breaking strength, electrical conductivity than the samples dispersed by only magnetic stirrer. An increase of silver nanoparticle generally results in an increase of enthalpy, a decrease of both cyclization temperatures and crystallinity. While 1 wt% AgNO3 loading is suitable for high breaking strength, 3 wt% AgNO3 loading is suitable for both high electrical conductivity and antimicrobial properties. Insulator polyacrylonitrile polymer becomes a semiconducting material.
30 November 2023 in Journal of Applied Polymer Science
Today a wide variety of wearable electronics are in our daily lives and their uses are increasing. The development of portable, flexible, lightweight, cost‐effective, and stable devices that produce sustainable energy with renewable approaches in the field of wearable electronics, as in every field, is one of the important issues of today. According to their volume and weight, the use of nanofibers with high surface area in energy‐generating devices may bring them advantages such as lightness and higher energy density. Therefore, in recent years, researchers have focused on the development of nanofiber‐based nanogenerators that produce energy using mechanical energy in a sustainable and renewable way. In this paper, self‐standing piezoelectric nanogenerator (PENG) fabrics were obtained by developing flexible composite poly(vinylidene fluoride) (PVDF) nanofiber yarns doped with zinc oxide (ZnO) nanoparticles at different rates to provide higher power output. It has been characterized from electromechanical, structural, and morphological aspects. The most successful self‐standing PENG fabric obtained (at 5% ZnO loading) doubled the energy output of the fabric made from pure PVDF nanofiber yarn and provided a peak total power of 81 μW and a power density of 30 μW/cm2. The present results open up the field for the development of PVDF/ZnO‐based nanomats and their use in sensors and actuators in the healthcare and engineering industries.
12 February 2020 in Journal of Industrial Textiles
Solar energy is one of the most popular energy sources among the other renewable energies. Photovoltaic technology is a clean way to generate electricity from sunlight. Flexible photovoltaics enable portable electronic devices to power at off-grid conditions. Stainless steel mesh fabric was used as a substrate and electrode allowing the light to reach the photoactive layer. The photoactive layer and hole transport layer were deposited by the means of dip-coating like in the textile industry. The metal back electrode was evaporated in a thermal evaporator under vacuum. Promising results were obtained from photovoltaic measurements. About 0.69% power conversion efficiency was obtained from textile-based solar cells in this study. The textile-based metal fabric enables a flexible photovoltaic structure that can be integrated on non-planar surfaces to generate electricity, and also mesh structure allows the light to reach the photoactive layer.
Polymer-based organic solar cells are of great interest as they can be produced with low-cost techniques and also have many interesting features such as flexibility, graded transparency, easy integration, and lightness. However, conventional wide bandgap polymers used for the light-absorbing layer significantly affect the power conversion efficiency of organic solar cells because they collect sunlight in a given spectrum range and due to their limited stability. Therefore, in this study, polymers with different bandgaps were used, which could allow for the production of more stable and efficient organic solar cells: P3HT as the wide bandgap polymer, and PTB7 and PCDTBT as low bandgap polymers. These polymers with different bandgaps were combined with PCBM to obtain increased efficiency and optimum photoactive layer in the organic solar cell. The obtained devices were characterized by measuring optical, photoelectrical, and morphological properties. Solar cells using the PTB7 and PCDTBT polymers had more rough surfaces than the reference cell using P3HT. The use of low-bandgap polymers improved Isc significantly, and when combined with P3HT, a higher Voc was obtained.
30 May 2025 in Macromolecular Materials and Engineering
This study presents the development of high‐performance poly(vinylidene fluoride) (PVDF) based piezoelectric nanocomposites incorporating branched carbon nanotubes (bCNTs) and zinc oxide nanowires (ZnO NWs) through a scalable melt mixing process. ZnONWs with uniform morphology (mean diameter: 36.5 nm) are successfully synthesized and characterized. FTIR analysis confirms that incorporating bCNTs into PVDF significantly enhances the β‐phase content, while adding ZnO NWs (1–10 wt.%) resulted in progressive intensification of β‐phase characteristic peaks, with higher ZnO content showing stronger electroactive phase formation. The optimized composition (PVDF/0.5 wt.% bCNTs/5 wt.% ZnO NWs) demonstrates superior piezoelectric performance with a power density of 5.62 µW cm−2, voltage output of 1.55 V, and current output of 14.48 µA. Moreover, the composite exhibits excellent mechanical properties with a tensile strength of 48 MPa and maintains stable performance under cyclic loading. The enhanced performance is attributed to the synergistic effect between bCNTs and ZnO NWs, optimal β‐phase formation, and efficient charge transfer pathways. This study demonstrates the potential of melt‐mixed PVDF nanocomposites for practical energy harvesting applications.