Papers by Valerii Barbash
Bulletin of Kyiv Polytechnic Institute. Series Instrument Making
Problem. Humidity control is necessary for many areas of modern human life, including agriculture... more Problem. Humidity control is necessary for many areas of modern human life, including agriculture, food and automotive industries, electronics manufacturing, medicine and everyday life. A new trend in medical sensors is the use of flexible wearable sensors that can be attached to a person's body or the clothing adjacent to it. Such sensors are able to repeat the shape of the body and deform as needed, without breaking or causing discomfort to the patient. Today, nanocellulose (NC) is a rather promising humidity-sensitive material, which is characterized by high hydrophilicity and sufficient flexibility, and at the same time it is a biodegradable material. The purpose of the work. Development and research of flexible humidity sensors based on nanocellulose as a moisture-sensitive film, depending on the nature of the raw material and the method of NC manufacturing, as well as the configuration of the device electrodes. Research results. Three groups of humidity sensors were manufa...
chemistry of plant raw material, 2014
Flexible Humidity Sensors Based on Nanocellulose
2022 IEEE 41st International Conference on Electronics and Nanotechnology (ELNANO)
Nanocellulose-Based Biodegradable Bend Sensors
2022 IEEE 41st International Conference on Electronics and Nanotechnology (ELNANO)
Silicon Diode Structures Based on Nanowires for Temperature Sensing Application
2022 IEEE 41st International Conference on Electronics and Nanotechnology (ELNANO)
Оценка влияния амфотерных синтетических смол на степень удержания волокна и загрязнения подсеточных вод
Проблематика. Переробка макулатури характеризується погіршеним утриманням волокнистої маси на сіт... more Проблематика. Переробка макулатури характеризується погіршеним утриманням волокнистої маси на сітці папероробної (картоноробної) машини, що призводить до підвищення вмісту волокна у підсіткових водах і до збільшення втрат вихідної волокнистої сировини зі стічними водами. Мета дослідження. Оцінка впливу амфотерних полімерних смол (АПС) на ефективність утримання волокна на сітці та ступінь забруднення підсіткових вод. Методика реалізації. За стандартними методиками визначено ступінь утримання волокна і каламутність води, яка виникає у процесі виробництва паперу і картону під час формування на сітці папероробної машини. Результати дослідження. Побудовано графіки залежності каламутності підсіткової води від витрат АПС для різного ступеня млива для марок макулатури МС-5Б-2 і МС-8В-3. Підтверджено високу ефективність впливу АПС на ступінь утримання волокна на сітці папероробної машини. Встановлено оптимальні значення технологічних параметрів (ступеня млива і витрат АПС) для оцінки впли...
Одержання пероцтової целюлози із соломи вівса для виробництва паперу
Background. Development of technology for obtaining peracetic pulp from oat straw and its use in ... more Background. Development of technology for obtaining peracetic pulp from oat straw and its use in the production of one of the paper mass types.Objective. Determination of peracetic cooking technological parameters’ optimal values for oat straw peracetic cellulose quality indicators.Methods. The oat straw cooking was carried out with peracetic acid at 95 ± 1 °C from 90 to 180 min for hydromodulus 8:1 and 7:1, using a sodium tungstate catalyst. To determine the oat straw peracetic cellulose mechanical indexes, laboratory samples of paper weighing 70 g/m2 were made.Results. Technological parameters’ optimum values (temperature, cooking duration, hydromodulus, hydrogen peroxide and acetic acid concentration) for the oat straw delignification process were established. It is shown that the sodium tungstate catalyst addition to the cooking solution at a rate of up to 1 % of the plant raw material weight helps to reduce the lignin content in cellulose to 15 %. A diagram of the cellulose yie...
Оцінка впливу амфотерних полімерних смол на ступінь утримання волокна і забруднення підсіткових вод
Background. Waste paper recycling is characterized by deterioration in the content of fiber mass ... more Background. Waste paper recycling is characterized by deterioration in the content of fiber mass on the fourdrinier wire of a paper-making (cardboard-making) machine, which leads to the fiber content increase in the pit water and to an increase in losses of the source fiber raw material with waste water.Objective. The aim of the paper is to evaluate the influence of amphoteric polymer resins (APR) on the fiber content effectiveness on the fourdrinier wire and the pit water contamination degree.Methods. According to standard techniques, the degree of fiber content and water turbidity, which arises in the paper and cardboard production during the formation on the paper-making machine fourdrinier wire, is determined.Results. The graphs of the dependence of the pit water turbidity on the APR consumption for different milling degree for MS-5B-2 and МС-8В-3 waste paper grades have been constructed. The high efficiency of the APR influence on the fiber content degree on the PPM wire is con...
Biomedical Journal of Scientific and Technical Research, Oct 28, 2020
Проблематика. Одержання зі щорічно відновлюваної рослинної сировини, зокрема із волокон конопель,... more Проблематика. Одержання зі щорічно відновлюваної рослинної сировини, зокрема із волокон конопель, мікрокристалічної целюлози (МКЦ), придатної для використання у хімічній промисловості. Мета дослідження. Розробка технології отримання МКЦ із волокон конопель для скорочення кількості стадій технологічного процесу та визначення оптимальних значень основних технологічних параметрів процесів хелатування і гідролізу пероцтової конопляної целюлози, за яких показники якості одержаної МКЦ будуть задовольняти вимоги нормативних документів. Методика реалізації. Пероцтове варіння волокон конопель тривалістю від 60 до 240 хв проводили за гідромодуля 10:1, температури 90 ± 1 °С. Процес хелатування целюлози трилоном Б досліджували за витрат від 5 до 30 % у кислому та лужному середовищах. На заключній стадії одержання МКЦ проводили гідроліз конопляної целюлози сульфатною кислотою за концентрації від 0,5 до 2,0 %, гідромодуля 15:1 і температури 90 ± 1 °С протягом 90 хв. Показники якості одержаної МКЦ...
Спосіб одержання мікрокристалічної целюлози із волокон конопель
Background. Obtaining from annually renewable plant raw materials, in particular from hemp fiber,... more Background. Obtaining from annually renewable plant raw materials, in particular from hemp fiber, microcrystalline cellulose (MCC), which is suitable for use in the chemical industry.Objective. The was aim of the paper is to develop a technology for obtaining MCC from hemp fibers to reduce the number of the technological process stages and to determine the optimum values of the main technological parameters of the chelating and hydrolysis processes of peracetic hemp pulp, in which the quality indicators of the obtained MCC will meet the requirements of regulatory documents.Methods. Peracetic cooking of hemp fibers was carried out at liquor to solid ratio 10: 1 and temperature of 90 ± 1 °C, ranging from 60 to 240 min. The process of chelating pulp by Trilon B was investigated at consumption from 5 to 30 % in acidic and alkaline environments. At the final stage of MCC preparation, the hemp pulp hydrolysis process was carried out by sulfate acid at its concentration of 0.5 to 2.0 %, li...
Мікрокристалічна целюлоза із луб’яних рослин
It was found that the chemical composition of flax fiber is common to cotton fiber, but differs f... more It was found that the chemical composition of flax fiber is common to cotton fiber, but differs from the stems of hemp and kenaf, softwood and hardwood because of higher content of ash, lesser lignin and pentosans content. Stems of hemp and kenaf compared with wood at approximately the same cellulose content have lesser lignin content, ash content and a much larger number of substances that dissolve in water and NaOH. It is shown that the water preliminary hydrolysis of bast plants compared with acid preliminary hydrolysis leads to less extraction of herbal minerals, hemicelluloses and cellulose fractions of low molecular weight. Increasing liquid to solid ratio in acid preliminary hydrolysis reduces mineral content in fibers and stems of plants, resulting in decreased yield and increased content of residual lignin in pulps. Cellulose was obtained by alkaline-sulfite alcohol method of bast plants delignification. Different schemes of bleaching organosolvent pulp using various charge...
Microsystems, Electronics and Acoustics
The humidity sensor is an important device used in many areas of human life, such as agriculture,... more The humidity sensor is an important device used in many areas of human life, such as agriculture, medicine, industry, meteorology and more. Most often, synthetic polymers are used for the manufacture of humidity sensors, which after the end of their operation are accumulated in the form of electronic waste, polluting the environment. Currently, biodegradable polymers are in great demand. Such materials include nanocellulose, which can be made from both wood and plant raw materials. It has already been proven that nanocellulose is a promising material for use in humidity-sensitive devices. However, it was not clear the effect of sensitive film’s thickness on the characteristics of humidity sensors. In this work, capacitive humidity sensors based on nanocellulose were fabricated. Nanocellulose (NC) was obtained from reeds by the TEMPO method. The moisture-sensitive layer of NC was applied by dripping. Static (sensitivity, response, hysteresis) and dynamic (response time, recovery tim...
Biomedical Journal of Scientific and Technical Research, 2020
The chapter describes the chemical structure and hierarchical organization of cellulose fibers, c... more The chapter describes the chemical structure and hierarchical organization of cellulose fibers, characteristics of non-wood plant raw materials (NWPM), and methods for preparing pulp and nanocellulose (NC). NWPM have the necessary reserves and properties to make up for a possible shortage of wood fiber for pulp production. The methodology for evaluating the efficiency of the delignification processes of plant raw materials is presented. A two-stage technology for producing pulp for the preparation of NC by environmentally friendly organosolvent methods of NWPM delignification is proposed. Methods for preparing nanocellulose are described. The technological parameters of the extraction of NC from pulp are discussed. The influence of NC on the properties of composite materials is analyzed. Areas of use for NC from NWPM are shown.
Determination of thermodynamic characteristics of heteromolecular association process, freed of contribution of specific solvation
Theoretical and Experimental Chemistry, 1986
The problem of considering separately the contributions of the universal and specific solvation o... more The problem of considering separately the contributions of the universal and specific solvation of components of a system to the thermodynamic characteristics of a heteromolecular association process are discussed. An expression is presented for calculating the equilibrium constants of the process of formation of addition products under universal solvation conditions, where the change in all of the thermodynamic characteristics of the process is determined by only a change in the dielectric constant of the medium.
The study describes the preparation of nanocellulose from organosolv hemp pulp (OHP) and its appl... more The study describes the preparation of nanocellulose from organosolv hemp pulp (OHP) and its applications in composition of paper for food packaging as an alternative to packaging from petroleum products. OHP was obtained from renewable plant materials hemp fibers by extraction with NaOH solution and cooking using a mixture of acetic acid and hydrogen peroxide. A stable transparent nanocellulose gel was extracted from OHP by acid hydrolysis followed by ultrasonic treatment. It was found that an increase in the consumption of sulfuric acid, temperature and duration of the OHP hydrolysis process improves the quality indicators of hemp nanocellulose. A linear dependence of the tensile strength and transparency of nanocellulose films on their density has been established. Morphological (SEM), structural (FTIR and XRD) and thermal analysis (TGA) of hemp fibers, OHP and nanocellulose were carried out. Nanocellulose films had a density of up to 1.56 g/cm3, a tensile strength of up to 66.7 ...
Preparation, Properties and Application of Miscanthus Nanocellulose as Coating Layer
The data on the preparation of nanocellulose from organosolvent miscanthus pulp and its applicati... more The data on the preparation of nanocellulose from organosolvent miscanthus pulp and its application as coating layer in the production of bag paper are reported. The influence of technological factors on the properties of nanocellulose films was determined. The obtained nanocellulose films had density up to 1.46 g/cm3, transparency up to 80%, crystallinity degree up to 77% and tensile strength up to 70 MPa. The properties of nanocellulose films studied by means of electron absorption spectra, XRD and AFM methods. The bag paper with consumption of nanocellulose of 5 g/m2 has mechanical properties of 12–68% higher and the elongation increases 2.9 times than paper without the use of surface treatment. The using of obtained nanocellulose as a coating layer exhibit great potential its application for improving fiber-based mechanical and barrier properties of paper and cardboard.
Reactive Ion Beam Sputtered Molybdenum Oxide Thin Films for Optoelectronic Application
Molybdenum oxide thin films were synthesized by reactive ion beam sputtering technique. The effec... more Molybdenum oxide thin films were synthesized by reactive ion beam sputtering technique. The effect of deposition temperature and annealing on surface morphology, electrical and optical parameters of molybdenum oxide thin films and heterojunctions based on them were determined. In particular, obtained thin films exhibit photosensitive properties (photo-sensitivity coefficient is about 200 μA/1mV), heterojunctions based on them are characterized by the rectifying properties (rectification coefficient is almost 300 at applied voltage of 0.5V) and photovoltaic properties (open-circuit voltage is 215 mV and short-circuit current with one point contact is up to 2.4 mA).
The aim of this study was to carry out a comparative analysis of various kinds of annual plants a... more The aim of this study was to carry out a comparative analysis of various kinds of annual plants and to investigate the process of obtaining pulp from these plants by a peracetic acid solution. The microscopic structure and chemical composition of the stalks of non-traditional annual plants for pulp and paper industry, such as wheat, rape, amaranth, lavatery, sverbiga and schavnat, were studied. It was established that their microscopic structure and chemical composition are similar to those of other kinds of non-wood plants, but are, nevertheless, different from those of softwoods and hardwoods. The effect of the duration of oxidative-organosolvent delignification of these plants on the quality of peracetic acid pulp was investigated. It was shown that oxidation of lignin and its transfer into solution occurs with varying intensity for different annual plants. It was also evidenced that the peracetic acid pulps obtained from the investigated plants may be arranged in the following o...
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Papers by Valerii Barbash