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...

Морфологические и физико-химические свойства наноструктурированной целлюлозы, полученной химическим и биологическим способами

The authors obtained samples of chemically pure, crystalline, microand nanostructured cellulose of various modifications using two approaches – biological and chemical. They studied these cellulose samples via scanning electron microscopy (SEM), thermogravimetric analysis, and infrared (IR) spectroscopy. To prepare cellulose microcrystals, they used the mild acid treatment method based on glycerolacid mixtures for treating cotton fibers. They showed that the chemical processing of cotton fiber ensured its dispersion with generation of microcrystals surrounded by a partially preserved amorphous shell. The authors produced bacterial cellulose (BC) films using the Komagataeibacter xylinus C3 strain in surface cultivation conditions. With a view of obtaining higher-quality SEM images, they applied chemical fixation of lipids and proteins with critical drying to fix the process of nanofiber synthesis by bacterial cells. The two-step fixation method helped find the fibrillar structure of a cellulose film, while the morphology of bacterial cells was not deformed. The authors made a comparative analysis of the IR spectroscopy results between chemically synthesized cellulose microcrystals and BC. The obtained cellulose samples do not contain lignin and hemicellulose, both samples are highly crystalline. The BC has an ordered structure, higher crystallinity and gets carbonized when exposed to air pyrolysis. A thermogravimetric analysis of the samples shows the absence of thermally stable impurities. Both cellulose samples of biological and chemical origin are thermally stable, and the initial decomposition temperature is high enough for cellulose materials. These results show that the authors have managed to create nanocellulose materials that might be potentially applied in various industries, such as pharmaceuticals, functional composites, engineering, 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...

Preparation of high performance micro- and mesoporous carbon-based sorbents from rice husk and walnut shell

Activated carbon (AC) is a porous substance that is obtained from various carbonaceous materials of organic origin: charcoal, coal coke, rice husk, walnut shell and other materials. AC has a huge number of pores and is characterized by a large surface area per unit mass, as a result of which it has a high adsorption capacity...

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

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