Obtaining of Carbon Nanotubes in Reactor with Fluidized Bed of Catalyst

The researching activity related to CNTs has grown most significantly over the past 10 years. Since 2006, world capacities of production of CNTs have increased 10-fold. The annual number of scientific publications on CNT and issued patents continues to grow [1]. Carbon nanotubes are used in many areas, such as energy, biotechnology, microelectronics, textiles, etc...

Gas Sensitive Materials Based on Polyacrylonitrile Fibers and Nickel Oxide Nanoparticles

The results of the synthesis of PAN/NiO composite fibers by the electrospinning method are presented. The electrospinning installation included a rotating drum collector for collecting fibers. Nickel oxide nanoparticles were synthesized by solution combustion synthesis from nickel nitrate and urea. It was shown that monophase NiO nanoparticles with average particle sizes of 154 nm could be synthesized by this method. NiO nanoparticles were investigated by X-ray diffraction analysis and scanning electron microscopy. Based on NiO nanoparticles, composite PAN/NiO fibers were obtained by electrospinning. The obtained composite fibers were modified with heat treatment (stabilization and carbonization) processes. Obtained C/NiO fibers were investigated by SEM, and EDAX. It was shown that obtained composite fibers could be used for the detection of acetone and acetylene in air. These results show that C/NiO based electrospun fibers have potential applications in gas sensors

Gas Sensitive Materials Based on Polyacrylonitrile Fibers and Nickel Oxide Nanoparticles

The results of the synthesis of PAN/NiO composite fibers by the electrospinning method are presented. The electrospinning installation included a rotating drum collector for collecting fibers. Nickel oxide nanoparticles were synthesized by solution combustion synthesis from nickel nitrate and urea. It was shown that monophase NiO nanoparticles with average particle sizes of 154 nm could be synthesized by this method. NiO nanoparticles were investigated by X-ray diffraction analysis and scanning electron microscopy. Based on NiO nanoparticles, composite PAN/NiO fibers were obtained by electrospinning. The obtained composite fibers were modified with heat treatment (stabilization and carbonization) processes. Obtained C/NiO fibers were investigated by SEM, and EDAX. It was shown that obtained composite fibers could be used for the detection of acetone and acetylene in air. These results show that C/NiO based electrospun fibers have potential applications in gas sensors

Obtaining of Carbon Nanotubes in Reactor with Fluidized Bed of Catalyst

The researching activity related to CNTs has grown most significantly over the past 10 years. Since 2006, world capacities of production of CNTs have increased 10-fold. The annual number of scientific publications on CNT and issued patents continues to grow [1]. Carbon nanotubes are used in many areas, such as energy, biotechnology, microelectronics, textiles, etc...

Rice-Husk-Based Materials for Biotechnological and Medical Applications

This review contains the main research directions, which are directly aimed at converting materials based on rice husks particularly, for their role for medicine and biotechnology. Especially in developing countries, more than 95% of rice husks are produced. Although numerous studies have been conducted on the production of various materials from rice husks, the existing scientific information is still widely scattered in the literature. Therefore, this review article provides extensive information on the work of various researchers, including the Institute of Combustion Problems (Almaty, Kazakhstan), on the production of various materials from rice husks and their physico-chemical characteristics. The main applications of rice husk materials in medicine are discussed. The ways of prospective conversion of rice husks for biotechnological purposes are considered

PAN—Composite Electrospun-Fibers Decorated with Magnetite Nanoparticles

The results of the synthesis of PAN(polyacrylonitrile)-magnetite composite fibers using the electrospinning method are presented. The electrospinning installation included a rotating drum collector for collecting fibers. Magnetite nanoparticles were synthesized using chemical condensation from an iron chloride solution. It was shown that homogeneous Fe3O4 magnetite nanoparticles with particle sizes of 6–16 nm could be synthesized using this method. Magnetite nanoparticles were investigated using X-ray diffraction analyses and transmission electron microscopy. Based on magnetite nanoparticles, composite PAN/magnetite fibers were obtained through electrospinning. The obtained composite fibers were investigated using scanning electron microscopy, X-ray diffraction analyses, and elemental analyses. It was shown that the magnetite nanoparticles were uniformly distributed on the surface of the fibers. A comparison of PAN fibers without any added magnetite to PAN/magnetite fibers showed that the addition of magnetite led to a decrease in the value of the fiber diameter at the same polymer concentration and under the same electrospinning process conditions

Investigations of Activated Carbon from Different Natural Sources for Preparation of Binder-Free Few-Walled CNTs/Activated Carbon Electrodes

In this study, we present another approach to fabricating high-performance supercapacitor electrodes by combining activated carbon particles with carbon nanotubes (AC/CNT). We synthesized activated carbon from diverse biomass sources using a carbonization process and chemical activation with KOH. By incorporating carbon nanotubes, we significantly augmented the electrode’s surface area, resulting in exceptional ion transport and a substantial increase in specific capacitance. Our investigation reveals that the optimized composition, 85:10:5 of AC, CNT, and conductive additive, achieved outstanding specific capacitance values, notably 125.6 F g−1 at 1 mV s−1 and 118 F g−1 at 1 A g−1, along with a maximum energy density of 4 Wh kg−1. Electrochemical impedance spectroscopy (EIS) further demonstrated the superior charge transfer capabilities of these electrodes, notably at a frequency range from 100 kHz to 10 mHz. Additionally, our research highlights the influence of different biomass precursors, such as apricot kernels, walnut shells, and rice husks, on the electrochemical behavior of these electrodes. Overall, this study provides valuable insights into the development of high-performance supercapacitors, emphasizing the potential of diverse biomass sources in optimizing electrode materials