Journal articles: 'Destruction of cellulose'

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Kholodkova, E. M., A. V. Bludenko, V. N. Chulkov, and A. V. Ponomarev. "Cellulose destruction by electron-beam-induced heating." Russian Chemical Bulletin 59, no. 9 (September 2010): 1827–33. http://dx.doi.org/10.1007/s11172-010-0319-5.

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Vaniushenkova, Anna A., Elina E. Dosadina, Anna A. Hanafina, Sergey V. Kalenov, Nikolay S. Markvichev, and Alexey A. Belov. "Synthesis and study of the properties of composite materials based on cellulose and chitosan containing various therapeutic agents. Part 3. Hydrolytic destruction of dressings based on dialdehydecellulose." Butlerov Communications 59, no. 8 (August 31, 2019): 47–59. http://dx.doi.org/10.37952/roi-jbc-01/19-59-8-47.

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Creating systems for targeted delivery of drugs to the affected organ is one of the most promising areas for the development of systems with controlled release of the active substance. Polysaccharides are widely used as drug carriers. However, most of them are chemically inert and require preliminary functionalization in order to interact with physiologically active compounds (therapeutic agents-TA). A simple and effective method for introducing reactive groups is the periodic oxidation of the polysaccharide by the Malaprade reaction. While cellulose is insoluble in water and resistant to weak solutions of acids and alkalis, dialdehyde cellulose (DAC is the product of the periodic oxidation of cellulose) and its derivatives are destroyed in water and weakly acidic and slightly alkaline solutions. This process is called hydrolytic destruction. The kinetics of hydrolytic destruction is described by semi-logarithmic anamorphosis, which allows us to calculate the rate constants of hydrolytic destruction as the rate constant of first-order reactions. The products of hydrolytic degradation were studied by UV spectroscopy and using 3,5-dinitrosalicylic acid (DNSA). The degradation products of C and DAC were also studied by the phenol-sulfur method. From the data presented and cited earlier, it follows that when our composite material is placed in a liquid medium, the hydrolytic destruction of the drug immediately begins. What can be connected with the breakdown of both the carrier – TA bonds (DAC, C, Ct carriers) and the destruction of the carrier itself. Under the conditions of the organism, biological destruction can also join process. Biodestruction is the process of destruction (both carriers and immobilized TAs) under the action of the body's enzymes. Using IR spectroscopy, cellulose carriers were studied before and after exposure to 1/15M FB medium (pH 6.2 and 37 °C) for 48 hours. As can be seen from the data obtained, primarily for DAC samples, significant changes in the spectrum are visible in the 1800-1600 and 900 cm-1 fields. The results of experimental toxicological studies of samples of various cellulosic materials allow us to conclude that the samples studied do not have toxic, hemolytic, allergenic effects, as well as mutagenic activity.

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Gupta, Ashwani K. "Thermal Destruction of Cellulose and Surrogate Solid Wastes." Journal of Propulsion and Power 16, no. 4 (July 2000): 615–22. http://dx.doi.org/10.2514/2.5617.

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Dubyago, Marina N., Irina A. Poluyanovich, and Nikolay K. Poluyanovich. "Thermodynamic Approach for Identifying Oxidative Processes Insulation Breakdown." Applied Mechanics and Materials 752-753 (April 2015): 1153–57. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.1153.

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Problematic issues insulation of power cable systems (PCS) based on the design and development of non-destructive methods are considered in the paper. The basic components of the PCS, destroying the insulation, are determined. The analytical method for assessing the oxidation processes of cellulose with the definition of the most probable is proposed. The approach for identifying the main processes of destruction of the insulation allows more detail to present background to the development of partial discharges (PD) in insulation and to identify measures for minimizing processes that lead to the destruction of the insulation PCS.

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Doncea, Sanda Maria. "FTIR Analysis Both for Degradation and Treatment with Nanoparticles of Historical Paper." Proceedings 29, no. 1 (October 16, 2019): 88. http://dx.doi.org/10.3390/proceedings2019029088.

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Мамлеева (Mamleeva), Надежда (Nadezhda) Алексеевна (Alekseevna), Андрей (Andrey) Николаевич (Nikolaevich) Харланов (Kharlanov), Дмитрий (Dmitriy) Германович (Germanovich) Чухчин (Chukhchin), Наталья (Natal'ya) Григорьевна (Grigor'evna) Базарнова (Bazarnova), and Валерий (Valeriy) Васильевич (Vasil'evich) Лунин (Lunin). "DEGRADATION OF PINE WOOD STRUCTURE WHEN OZONOLYTIC DELIGNIFICATION." chemistry of plant raw material, no. 1 (March 6, 2019): 85–94. http://dx.doi.org/10.14258/jcprm.2019015143.

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The pine wood degradation under ozonation was studied. It was determined the contents of lignin (LG) and cellulose (CL) in cellulose-containing material (CM) obtained from the ozonized wood. The degree of polymerization (DP) of cellulose from CM was determined. Samples of CM were investigated using IR diffuse reflectance (DRIFT) spectra and XRD analysis. HPLC analysis of water-soluble LG ozonolysis products was conducted. Ozonation results in 40–42% delignification degree of wood. Aromatics destruction is confirmed by DRIFT spectra. The intensity of stretching band at 1736 cm-1 of unconjugated C=O groups in LG or hemicelluloses markedly increases. A stoichiometric ratio of absorbed ozone and an amount of destructed guaiacylpropane units as well as a composition of water-soluble products show that ozonolysis is a primary mechanism of aromatics degradation in wood. The data on XRD analysis, the amounts of removed LG and the change of cellulose DP allow conclusion that the wood ozonation is accompanied by a destruction of hemicelluloses and amorphous cellulose in the wood. It is shown that the specific ozone uptake £1.5 mmol O3/g matches the domination of the wood delignification with the lowest degradation of cellulose fibers and acceptable efficiency in terms of the ozonation process.

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Osovskaya, Iraida Ivanovna, and Veronika Sergeyevna Antonova. "THE INFLUENCE OF SURFACE DESTRUCTION ON THE HYDROPHILICITY AND ABILITY TO FORM CONNEC-TIONS OF THE CELLULOSE FIBERS." chemistry of plant raw material, no. 1 (March 5, 2020): 315–20. http://dx.doi.org/10.14258/jcprm.2020016269.

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When using cellulose fibers to produce paper, the main role is played by the state of the surface of the fiber and its ability to adhesive-cohesive interaction. The main indicators characterizing the surface of the fiber are development and roughness, chemical heterogeneity, depending on the presence of various functional groups, as well as structural heterogeneity of the surface layers, leading to the formation of a stronger bond between the fibers. The surface modification of the fiber was carried out by partial acid hydrolysis. The study is aimed at optimizing hydrolysis, choosing methods for its control, obtaining physicochemical and physicomechanical characteristics of partially hydrolyzed cellulose, and increasing the ability to bind cellulose fiber. A method has been developed for producing modified cellulose with improved adhesion-cohesive properties by surface destruction of wet cellulose fibers during hydrolysis. The patterns of activation of the surface properties of cellulose fibers are obtained. The effect of partial acid hydrolysis on the development of the surface of the fiber in the absence of "wet" grinding with water shortage is shown. The effect of short chains and reducing carbonyl groups of cellulose macromolecules on the binding capacity of modified cellulose has been established. The optimal content of short chains of cellulose macromolecules, which is 12%. Such a content of short chains of modified fibers by acid hydrolysis was detected at a temperature of 363 K and an exposure time of 40 s; under these optimal conditions, the strength of the experimental castings increases by 70%.

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Manucharova, N. A. "The microbial destruction of chitin, pectin, and cellulose in soils." Eurasian Soil Science 42, no. 13 (December 2009): 1526–32. http://dx.doi.org/10.1134/s1064229309130146.

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Badretdinova, I. V., Ye A. Vorontsova, V. V. Kasatkin, and A. B. Spiridonov. "BIOLOGICAL METHODS OF DESTRUCTION OF THE FLAX FIBER CELLULOSE COMPLEX." Bulletin of Izhevsk State Agricultural Academy, no. 1 (2021): 33–38. http://dx.doi.org/10.48012/1817-5457_2021_1_33.

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10

Stepina, Irina Vasilevna. "Change in Crystalline Structure of Cellulose Caused by Wood Preservation." Materials Science Forum 923 (May 2018): 51–55. http://dx.doi.org/10.4028/www.scientific.net/msf.923.51.

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Сhemical interaction of cellulose with reactive groups of four-coordinate boron-nitrogen compounds is an intercrystalline process proceeding without destruction of cellulose crystalline structure; probably, the modifier molecules react with easier accessible hydroxyl groups of the amorphous cellulose regions. The formation of B-O-C ether bonds between OH groups of modifiers and more reactive hydroxyl groups of amorphous parts of cellulose results in redistribution of hydrogen bonds and, as a consequence, to rectification of cellulose macromolecules. Thus, when cellulose is treated with compositions based on four-coordinate boron-nitrogen compounds, crystalline structure of cellulose is not disrupted, hence this process can be called a "mild" modification. Such modification does not lead to accelerated aging of cellulose materials, rapid loss of strength and increases durability of wooden structures.

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Momziakova, Kseniya Sergeyevna, Aleksey Aleksandrovich Shinkarev, Timur Rustamovich Deberdeev, Zimfira Talgatovna Valishina, Aleksandr Aleksandrovich Berlin, and Rustam Yakubovich Deberdeev. "X-RAY STRUCTURAL ANALYSIS OF COTTONS AND HERBACEOUS CELLULOSE." chemistry of plant raw material, no. 3 (September 27, 2021): 61–71. http://dx.doi.org/10.14258/jcprm.2021038852.

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It was found that the extrusion treatment of cotton cellulose in an aqueous medium, followed by drying and grinding on a hammer mill leads to a decrease in the crystallite size in the transverse direction ([110] and [100]) as a result of mechanical destruction of cellulose macromolecules, and the subsequent acid hydrolysis of cellulose in H2SO4 solutions to an increase in the size of crystallites in the transverse direction ([110], [110] and [100]) due to co-crystallization processes. It is shown that alkaline cooking of cellulose-containing material, followed by extrusion processing, washing, drying and grinding on a hammer mill leads to an increase in the transverse dimensions of crystallites in the [110] and [100] directions for flax cellulose and in the [110], [110] and [100] – for cellulose from oats and alfalfa as a result of partial removal of lignin and hemicelluloses from the cellulose-containing material. Differences were revealed in the sizes of the coherent scattering regions and the parameters of the crystallographic cell of cellulose samples from cotton and herbaceous plants (flax, oats, and alfalfa), as well as between samples from oats and alfalfa obtained under the same conditions with the same type of feedstock (straw). It has been established that the proposed stepwise technology for processing cotton and linen fibers leads to a slight decrease in the degree of crystallinity and the average degree of polymerization, which indicates that the developed technology for obtaining high-viscosity powder celluloses for various purposes is promising. Correlation coefficients are established between the values of the degree of ordering of the structure of cellulose samples from various plant raw materials, calculated using X-ray diffraction analysis and FT-IR spectroscopy, which make it possible to adequately compare all the known literature and experimental data.

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Kasatkina, N. Yu, I. V. Badretdinova, A. A. Litvinyuk, and V. V. Kasatkin. "Substantiation of technological parameters for the production of flax pulp by alkaline cooking in the microwave field." IOP Conference Series: Earth and Environmental Science 949, no. 1 (January 1, 2022): 012111. http://dx.doi.org/10.1088/1755-1315/949/1/012111.

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Abstract Flax fiber is the most valuable, rapidly renewable source of cellulose. To isolate cellulose from the fiber, it is necessary to get rid of its non-cellulose components: lignin, pectin substances, waxes and hemicellulose. These substances can be removed by cooking flax fiber in an alkaline solution. To intensify the process of destruction of the non-cellulose complex, it is proposed to use the energy of the electromagnetic field of ultrahigh frequencies. The article presents the results of theoretical and experimental studies aimed at establishing the dielectric characteristics of the system components, which make it possible to prove the effectiveness of the effect of the microwave field on the process of destruction of the non-cellulose complex and to deduce the permissible limits of technological parameters. For the effective management of the technological process of alkaline cooking, the dielectric characteristics of the system components are established on the basis of theoretical and experimental studies. To solve this problem, the system was divided into components: fiber, solution, heterogeneous system. Further, the characteristics of each component are determined separately. The established characteristics showed the following values: the dielectric constant of the fiber in the solution reached a value of 24.8, the dielectric constant of the solution-73, the dielectric constant of the heterogeneous system is 64.55. These values allow you to conduct the technological process of delignification with high efficiency indicators.

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Semenova, M. V., A. V. Gusakov, V. D. Telitsin, and A. P. Sinitsyn. "Enzymatic Destruction of Cellulose: Characteristics of the Kinetic Interaction of Lytic Polysaccharide Monooxygenases and Individual Cellulases." Applied Biochemistry and Microbiology 57, no. 5 (September 2021): 618–25. http://dx.doi.org/10.1134/s0003683821050136.

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14

Cherezova, E. N., Yu S. Karaseva, and K. S. Momzyakova. "HYDROPHILIC RUBBER BASED ON BUTADIENE-NITRILE RUBBER AND POWDER CELLULOSE OF PLANT ORIGIN." All the Materials. Encyclopedic Reference Book., no. 7 (2021): 33–37. http://dx.doi.org/10.31044/1994-6260-2021-0-7-33-37.

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It has been established that the introduction of powdered cellulose, obtained by chemo-mechanical destruction from oat straw, into the composition of rubbers as a hydrosorption filler increases the conditional tensile strength of vulcanizates in comparison with samples without this filler. It was revealed that the degree of swelling of rubbers containing powdered cellulose from oat straw, the pH of the aqueous medium and the degree of mineralization have little effect.

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15

Sezonenko, O. B., O. O. Vasechko, V. V. Aleksyeyenko, and A. V. Snihur. "INVESTIGATION OF THE PROCESSES OF THERMAL DESTRUCTION OF CELLULOSE-CONTAINING (PAPER) WASTE." Energy Technologies & Resource Saving, no. 3 (September 20, 2021): 58–62. http://dx.doi.org/10.33070/etars.3.2021.05.

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Materials of practical research work on thermal destruction of paper waste were presented. The main task was The comprehensive study of the aspects of carbon formation on the basis of analytical studies was considered, as well as using a specially built laboratory installation — a waste graphitizer. Research has been carried out on the effectivity of application of pyrolysis gases of the process as fuel to maintain the temperatures of the thermal destruction reaction. Practical examples have proved the possibility and expediency of using the solid residue of the reaction as a component in various fields of production. Bibl. 10, Fig. 1, Tab. 3.

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16

Jain, Pooja, Mohd Aamir Mirza, Sushama Talegaonkar, Shyamasree Nandy, Mridu Dudeja, Nilima Sharma, Md Khalid Anwer, Saad M. Alshahrani, and Zeenat Iqbal. "Design and in vitro/in vivo evaluations of a multiple-drug-containing gingiva disc for periodontotherapy." RSC Advances 10, no. 14 (2020): 8530–38. http://dx.doi.org/10.1039/c9ra09569a.

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A gingiva disc of cellulose acetate phthalate and poloxaner F-127 was developed for the simultaneous delivery of multiple drugs, including minocycline, to promote alveolar bone regeneration by abolishing infection, impeding inflammation and averting collagen destruction.

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Stovbun, Sergey V., Mariya G. Mikhaleva, Aleksey A. Skoblin, Sergey V. Usachev, Sergey N. Nikolsky, Vasily A. Kharitonov, Kseniya I. Kovaleva, Galina G. Politenkova, Alexander S. Vedenkin, and Dmitry V. Zlenko. "Zhurkov’s Stress-Driven Fracture as a Driving Force of the Microcrystalline Cellulose Formation." Polymers 12, no. 12 (December 10, 2020): 2952. http://dx.doi.org/10.3390/polym12122952.

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Microcrystalline cellulose (MCC) is a chemically pure product of cellulose mechano-chemical conversion. It is a white powder composed of the short fragments of the plant cells widely used in the modern food industry and pharmaceutics. The acid hydrolysis of the bleached lignin-free cellulose raw is the main and necessary stage of MCC production. For this reason, the acid hydrolysis is generally accepted to be the driving force of the fragmentation of the initial cellulose fibers into MCC particles. However, the low sensibility of the MCC properties to repeating the hydrolysis forces doubting this point of view. The sharp, cleave-looking edges of the MCC particles suggesting the initial cellulose fibers were fractured; hence the hydrolysis made them brittle. Zhurkov showed that mechanical stress decreases the activation energy of the polymer fracture, which correlates with the elevated enthalpy of the MCC thermal destruction compared to the initial cellulose.

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Abdullaev, Kh M., and Sh T. Tuichiev. "Relationships governing the failure of triacetate cellulose in thermal oxidation destruction conditions." Strength of Materials 20, no. 9 (September 1988): 1190–94. http://dx.doi.org/10.1007/bf02082738.

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Luo, Xingxing, Baiquan Zeng, Yanan Zhong, and Jienan Chen. "Production and detoxification of inhibitors during the destruction of lignocellulose spatial structure." BioResources 17, no. 1 (December 9, 2021): 1939–61. http://dx.doi.org/10.15376/biores.17.1.luo.

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Lignocellulosic biomass is a renewable resource that is widely abundant and can be used to produce biofuels such as methanol and ethanol. Because biofuels have the potential to alleviate shortages of energy in today’s world, they have attracted much research attention. The pretreatment of lignocellulose is an important step in the conversion of biomass products. The pretreatment can destroy the crosslinking effect of lignin and hemicellulose on cellulose, remove lignin, degrade hemicellulose, and change the crystal structure of cellulose. The reaction area between the enzyme and the substrate is enlarged, and the yield of subsequent enzymatic hydrolysis and microbial fermentation products is significantly increased. Conventional pretreatment methods help convert lignocellulosic material to sugars, but the treatments also produce some inhibitors, which are mainly organic acids, aldehydes, phenols, and other substances. They may affect the subsequent saccharification and growth of fermentation microorganisms, thereby reducing the bioconversion of the lignocellulose. It is therefore necessary to take effective means of detoxification. This paper reviews lignocellulose pretreatment methods, with an emphasis on inhibitors and their management. A summary is provided of detoxification methods, and the future use of lignocellulosic biomass for fuels prospects.

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Wang, Ying, Zhao-xuan Ding, Yan-hui Zhang, Chun-yan Wei, and Zi-chang Xie. "Luffa Pretreated by Plasma Oxidation and Acidity to Be Used as Cellulose Films." Polymers 11, no. 1 (December 27, 2018): 37. http://dx.doi.org/10.3390/polym11010037.

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Cellulose is the most abundant natural polymer on earth. With the increasing shortage of oil resources, people have been focusing more on producing natural cellulose. In this study, guaiacol was used as the model compound to investigate the degradation of lignin in luffa. A new cellulose material was extracted from natural luffa by a pretreatment based on the oxidation and acidity of glow discharge plasma in water. The produced luffa cellulose was dissolved in anhydrous phosphoric/polyphosphoric acid (aPPAC) solvent to prepare cellulose film. Results showed that the reactive species of OH·, HO2· and H3O+ were produced during the plasma discharge of water. The free radicals ·OH were useful in eliminating lignin by the destruction of aromatic structure, whereas H3O+ in eliminating hemicellulose in the luffa raw material. At the conditions of luffa powder concentration of 9.26 g/L, discharge time of 20 min, and plasma power of 100W, the cellulose component was increased to 81.2%. After 25 min, the luffa cellulose was completely dissolved in the aPPAC solvent at 0–5 °C. Thus, a regenerated cellulose film of cellulose II was prepared. The aPPAC solvent was a good non-derivatizing solvent for the luffa cellulose. The regenerated film exhibited good mechanical properties, wettability and a compact structure. Therefore, plasma pretreatment was an environmentally friendly and high-efficiency method for luffa degumming. The luffa cellulose can be well used in dissolution and regeneration in films.

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Ibragimov, Alexandr, Andrey Titunin, Tatiana Vachnina, and Irina Susoeva. "The decline of combustibility of heat-insulating composite plates from plant wastes." MATEC Web of Conferences 251 (2018): 01019. http://dx.doi.org/10.1051/matecconf/201825101019.

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The structure and factors of the process of production of heat-insulating composite plate materials from the waste of spinning of plant fibers are being developed. A disadvantage of the cellulose-containing filler composites is their increased flammability. The stages of thermal destruction of cellulose are considered. To determine the characteristics of the material that affect their fire hazard properties, the differential scanning calorimetry method was used. The paper substantiates the use of the method of introduction of fire retardant at the stage of formation the structure of composite. To reduce the flammability of composite materials from plant raw materials, it was suggested to use ammonium fluoride. The results of the determination of the degree of damage by mass in the case of burning in a “ceramic combustion chamber” of samples of a composite material with filler from irrecoverable waste produced by cotton and linen fibers are obtained. It has been established that the use of ammonium fluoride for the manufacture of heat-insulating composite plate materials from the irrecoverable waste produced by cotton and linen fibers makes it possible to obtain material with a degree of damage by mass of not more than 22 %. Key words: cotton, flax, spinning waste, cellulose, thermal destruction, differential scanning calorimetry, composite materials, loss of mass in combustion, ammonium fluoride.

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Везенцев, Александр, Alexander Vezentsev, Динь Тьиен Нгуен, Din' T'ien Nguen, Мария Михайлюкова, and Mariya Mihaylyukova. "COMPONENT COMPOSITION AND CHARACTERISTICS OF THE THERMAL DESTRUCTION PROCESS OF BAGASSA." Forestry Engineering Journal 8, no. 1 (March 19, 2018): 139–49. http://dx.doi.org/10.12737/article_5ab0dfc26f3564.53546946.

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The production of cane sugar accompanies the formation of a waste called bagasse, which can serve as a source for obtaining sorption-active materials. The purpose of this work was to determine the composition and the characteristics of thermal destruction of bagasse. The composition of the bagasse was determined - 47.59 wt. % cellulose, 26.92 wt. % hemicellulose, 21.53 wt. % lignin, 1.37 wt. % of the substance extracted with organic solvents and 2.59 wt. % of ash. In an oxidizing environment, the destruction of bagasse occurs intensively in the range 230-520°C with the release of thermal energy, in a protective medium in the range 240-395°C without the release of thermal energy.

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Rubleva, Natalia V., Marina I. Voronova, Oleg V. Surov, Anatoly G. Zakharov, Ekaterina O. Lebedeva, and Andrei V. Fineevskii. "PRODUCTION OF CELLULOSE NANOCRYSTALS BY HYDROLYSIS IN MIXTURE OF HYDROCHLORIC AND NITRIC ACIDS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 62, no. 12 (December 8, 2019): 85–93. http://dx.doi.org/10.6060/ivkkt.20196212.5984.

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In this work, cellulose nanocrystals (CNC) have been produced by hydrothermal method in a mixture of hydrochloric and nitric acids in molar ratios of 8:2, 7:3, 6:4 and 5:5. Hydrolysis of sulphate cellulose in the mixtures of nitric and hydrochloric acids was conducted in a sealed thick-walled stainless steel vessel with a teflon insert for 3 h at 110 °С. Properties of CNC have been characterized by applying different methods: elemental analysis, thermogravimetric analysis, IR spectroscopy, polarization optical microscopy, scanning electron microscopy, and dynamic light scattering. Yield of CNC, size and charge of the CNC particles, degree of polymerization, temperature of thermal destruction have been determined, and morphology of the CNC samples has been characterized. The highest CNC yield (32%) has been observed at a 7:3 ratio of nitric and hydrochloric acids. It has been established that the CNC particles are spherical and have an average size of 60-80 nm. An assumption has been made that presence of a strong oxidant (nitric acid) may cause hydrolysis of both amorphous and crystalline (in part) regions of cellulose, which affects the final shape of the CNC particles. It has been shown that the hydrolysis in a mixture of nitric and hydrochloric acids causes an oxidation of primary hydroxyl groups of the cellulose pyranose ring and formation of surface carboxyl groups. The CNC aqueous suspensions demonstrate high colloidal stability due to a rather high surface charge. It is noted that the CNC thermal stability is much higher than that of the CNC samples obtained by the standard sulfuric acid hydrolysis: the temperature of thermal destruction increases by 130-148 °С.

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Janardhnan, Sreekumar, and Mohini M. Sain. "Isolation of cellulose microfibrils - An enzymatic approach." BioResources 1, no. 2 (September 21, 2006): 176–88. http://dx.doi.org/10.15376/biores.1.2.176-188.

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Isolation methods and applications of cellulose microfibrils are expanding rapidly due to environmental benefits and specific strength properties, especially in bio-composite science. In this research, we have success-fully developed and explored a novel bio-pretreatment for wood fibre that can substantially improve the microfibril yield, in comparison to current techniques used to isolate cellulose microfibrils. Microfibrils currently are isolated in the laboratory through a combination of high shear refining and cryocrushing. A high energy requirement of these procedures is hampering momentum in the direction of microfibril isolation on a sufficiently large scale to suit potential applications. Any attempt to loosen up the microfibrils by either complete or partial destruction of the hydrogen bonds before the mechanical process would be a step forward in the quest for economical isolation of cellulose microfibrils. Bleached kraft pulp was treated with OS1, a fungus isolated from Dutch Elm trees infected with Dutch elm disease, under different treatment conditions. The percentage yield of cellulose microfibrils, based on their diameter, showed a significant shift towards a lower diameter range after the high shear refining, compared to the yield of cellulose microfibrils from untreated fibres. The overall yield of cellulose microfibrils from the treated fibres did not show any sizeable decrease.

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Romanova, Svetlana M., and Liliya A. Fatykhova. "INVESTIGATION OF REACTIONS OF INTERACTION OF CELLULOSE NITRIC ESTERS WITH CARBOXYLIC ACID CHLORIDES." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 64, no. 5 (May 13, 2021): 30–34. http://dx.doi.org/10.6060/ivkkt.20216405.6313.

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The chemical interaction of high-nitrogen cellulose ether with acetic, propionic, butyric and isobutyric acids has been studied. The general laws and features of the electrophilic substitution of functional groups of cellulose nitroesters are revealed. The preferred directions of the chemical interaction of cellulose nitrate with carboxylic acid chlorides are established: O-acylation of nitrate and hydroxyl groups; O-acylation of the glucopyranose ring; O-acylation of the ether bond with depolymerization of the chain of an SC molecule; hydrolysis of nitrate groups; destruction of the chain of a macromolecule of nitric acid ester with the formation of water-soluble organic compounds. The structure, properties and possibilities of using synthesized mixed cellulose ethers were studied. Effective methods have been developed for the chemical modification of cellulose nitrates with carboxylic acid chlorides. The probable directions of the reaction of the interaction of cellulose nitrates with electrophilic reagents are predicted based on quantum-chemical calculations of point charges on the atoms of the reacting molecules. The reactivity of highly substituted cellulose nitrates in reactions with carboxylic acid chlorides has been established. The optimal conditions for the interaction of cellulose nitrates with carboxylic acid chlorides have been identified and a mathematical model of the reaction kinetics has been constructed. The possibility of a directed change in the composition of chemically modified cellulose nitrates depending on the synthesis conditions has been established. As a result of the combined use of physicochemical research methods, the chemical composition was determined and the structure of the synthesized compounds was determined: cellulose acetyl nitrates, cellulose propionyl nitrates, cellulose butyryl nitrates, and cellulose isobutyryl nitrates. Using gel chromatography, it was found that the molecular weight characteristics of the synthesized samples are directly dependent on the conditions of their synthesis. It was found that electrophilic substitution of the functional groups of cellulose nitrate proceeds more intensively in the pyridine medium.

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Chen, Yian, Petra Pötschke, Jürgen Pionteck, Brigitte Voit, and Haisong Qi. "Aerogels Based on Reduced Graphene Oxide/Cellulose Composites: Preparation and Vapour Sensing Abilities." Nanomaterials 10, no. 9 (August 31, 2020): 1729. http://dx.doi.org/10.3390/nano10091729.

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This paper reports on the preparation of cellulose/reduced graphene oxide (rGO) aerogels for use as chemical vapour sensors. Cellulose/rGO composite aerogels were prepared by dissolving cellulose and dispersing graphene oxide (GO) in aqueous NaOH/urea solution, followed by an in-situ reduction of GO to reduced GO (rGO) and lyophilisation. The vapour sensing properties of cellulose/rGO composite aerogels were investigated by measuring the change in electrical resistance during cyclic exposure to vapours with varying solubility parameters, namely water, methanol, ethanol, acetone, toluene, tetrahydrofuran (THF), and chloroform. The increase in resistance of aerogels on exposure to vapours is in the range of 7 to 40% with methanol giving the highest response. The sensing signal increases almost linearly with the vapour concentration, as tested for methanol. The resistance changes are caused by the destruction of the conductive filler network due to a combination of swelling of the cellulose matrix and adsorption of vapour molecules on the filler surfaces. This combined mechanism leads to an increased sensing response with increasing conductive filler content. Overall, fast reaction, good reproducibility, high sensitivity, and good differentiation ability between different vapours characterize the detection behaviour of the aerogels.

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Nguyen, Phuong X. T., Kim H. Ho, Chi T. X. Nguyen, Nga H. N. Do, Anh P. N. Pham, Tai C. Do, Kien A. Le, and Phung K. Le. "Recent Developments in Water Treatment by Cellulose Aerogels from Agricultural Waste." IOP Conference Series: Earth and Environmental Science 947, no. 1 (December 1, 2021): 012011. http://dx.doi.org/10.1088/1755-1315/947/1/012011.

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Abstract Water pollution caused by inorganic and organic compounds affects seriously health risks and the destruction of the water balance of the ecosystem. Water remediation is one of the greatest challenges of the modern age, which is faced by several countries in over the world. Many advanced technologies have been developed in recent years to manage this alarming problem. One of the recent research directions is to utilize agricultural waste, which is an abundant, low-cost, eco-friendly source, to manufacture cellulose aerogels for the removal of heavy metals, dyes, and oils from contaminated water. This review paper focuses on the latest green fabrication of bio-aerogels from various cellulose-based plant waste and studies on the kinetics and influence of factors such as contact time, pH solution, initial concentration, and temperature on the adsorption process to better understand the mechanisms of water treatment by the cellulose aerogels. Based on the discussion and summary, the potential of agro-waste sources in their value-added chain by developing efficient water treatment cellulose aerogels is comprehensively overviewed.

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Yang, Jie, Jie Zhao, Bobo Wang, and Zhisheng Yu. "Unraveling aerobic cultivable cellulolytic microorganisms within the gastrointestinal tract of sheep (Ovis aries) and their evaluation for cellulose biodegradation." Canadian Journal of Microbiology 68, no. 4 (April 2022): 237–48. http://dx.doi.org/10.1139/cjm-2021-0338.

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Anaerobic cellulolytic microbes in the gastrointestinal tract (GT) of ruminants have been well-documented; however, knowledge of aerobic microbes with cellulolytic activities in the ruminant GT is comparably limited. Here, we unraveled aerobic cultivable cellulolytic microbes in the GT of Ujimqin sheep (Ovis aries) and evaluated the cellulolytic potential of the promising isolates. Twenty-two strains were found to possess cellulose-degrading potential by Congo-red staining and phylogenetic analysis of the 16S rDNA/ITS sequence revealed that all strains belonged to nine genera, i.e., Bacillus, Streptomyces, Pseudomonas, Lactobacillus, Brachybacterium, Sanguibacter, Rhizobium, Fusarium, and Aspergillus. Strains with high cellulolytic activity were selected to further evaluate the activities of various enzymes in lignocellulosic alfalfa hay (Medicago sativa). Among them, isolate Bacillus subtilis RE2510 showed the highest potential for cellulose degradation, considering the high endoglucanase (0.1478 ± 0.0014 IU mL−1), exoglucanase (0.1735 ± 0.0012 IU mL−1), and β-glucosidase (0.3817 ± 0.0031 IU mL−1) after 10-day incubation with alfalfa hay. A significant destruction effect of the cellulose structure and the attachment of B. subtilis RE2510 to the hay were also revealed using a scanning electron microscope. This study expands our knowledge of aerobic cellulolytic isolates from the GT of sheep and highlights their potential application as a microbial additive in the aerobic process of cellulose bioconversion.

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Paruta, Valentyn, Olga Gnyp, Leonid Lavrenyuk, and Iryna Grynyova. "The Influence of the Structure on the Destruction Mechanism of Polymer-Cement Plaster Coating." Key Engineering Materials 864 (September 2020): 93–100. http://dx.doi.org/10.4028/www.scientific.net/kem.864.93.

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The article considers the influence of the structure of polymer-cement plaster coating on the nature of its destruction during the operation of the wall structure. It was shown that the use of purposefully selected components of the mixture (RPP, polymer fiber, cellulose ethers, fine aggregate with a low modulus of elasticity, etc.) made it possible to increase the uniformity of its structure and contact area with masonry, reduce the number of cracks during hardening, and slow down their development during operation, increase the durability of it and the wall structure. The durability of the wall structure largely depends on the number of defects in the plaster coating and the contact area between it and the masonry.

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Fomenko, I. A., and S. N. Tuchkova. "Cellulose-containing waste recycling using fungi." New Technologies 17, no. 5 (December 21, 2021): 123–33. http://dx.doi.org/10.47370/2072-0920-2021-17-5-123-133.

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Accumulation of plant waste is a serious environmental problem. Mushrooms with high cellulolytic activity can process it into valuable products that will be useful in solving various industries and agriculture problems. The enzymes of the cellulolytic complex include 1,4-β-D-glucan-4-glucanohydrolase, exo-1,4-β-glucosidase, cellobiohydrolase, β-glucosidase. 1,4-β-D-glucan-4-glucanohydrolases destroy β-1,4-glycosidic bonds within the chain of cellulose and lichenin polysaccharides. Exoglucanases destroy β-1,3- and β-1,4-glycosidic bonds at the end of the molecule. Cellobiohydrolases cleave β-1,4-glycosidic bonds to form cellobiose and glucose. β-glucosidase complete the process of destruction. Fungi with high cellulolytic activity include both representatives of the Ascomycota and Basidiomycota divisions. Ascomycete Chaetomium globosum produces endoglucanases of two families and 8 cellobiohydrolases. Myceliophthora thermophila also produces endoglucanases and cellobiohydrolases, the most abundant of which is Mt Cel7A. The fungus is a promising producer of thermostable enzymes. Trichoderma reesei has a long history of safe use as a source of highly active cellulolytic enzymes and other valuable metabolites. LPMOs of the cellulolytic fungus Thielavia terrestris are considered auxiliary enzymes, but can negatively affect the main enzymes of the complex. Irpex lacteus also produces LPMO and a complete cellulolytic enzyme complex. The cellulolytic activity of fungi and their ability to grow on cheap substrates can be used to bioconvert plant waste into valuable products. One of the ways to utilize them is to convert into compound feed with a high protein content through the use of starter cultures. The use of mushrooms will increase the content of protein and simple carbohydrates, enrich the feed with fats. Another method is to obtain cellulases, which are widely used in many industries. Thanks to the production of biodiesel and bioethanol from cellulose-containing raw materials it is possible to solve the problem of lack of fuel by replacing energy carriers from non-renewable energy sources with their environmentally friendly counterparts. They are less toxic than diesel and gasoline and are also made from renewable resources.

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LAKA, MARIANNA, MARITE SKUTE, INESE FILIPOVA, VELTA FRIDRIHSONE, ULDIS GRINFELDS, JURIS ZOLDNERS, MARTINS SPADE, and IGORS SIVACOVS. "MICRO- AND NANOPARTICLES FROM HEMP SHIVES AND HEMP CELLULOSE IN PAPERMAKING." Cellulose Chemistry and Technology 54, no. 9-10 (November 11, 2020): 1031–36. http://dx.doi.org/10.35812/cellulosechemtechnol.2020.54.100.

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Nano- and microparticles were produced from hemp shives and hemp cellulose obtained thereof, using the thermocatalytic mechanical destruction method. The partially destructed material, at concentrations of 8-9%, was dispersed in water medium in a ball mill or ground without the presence of water in a ball mill (~15 h). In the first case, a gel-like dispersion, which contained nanoparticles and microparticles, was obtained. In the second case, microparticle powder (from hemp shives) was obtained. The obtained materials were used as fillers and coatings in paper sheets. The air resistance and mechanical properties of paper sheets were investigated. It has been established that the nano/microparticle fillers improve the mechanical properties and air resistance of paper sheets. The properties of paper are improved also by coatings made from nanoparticle gels on both sides of paper sheets. Therefore, the nano/microparticle fillers and coatings obtained from hemp shives and hemp cellulose can be used in papermaking, improving the properties of paper sheets.

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Crawford, Brad, and Ahmed Ismail. "Thermodynamic and Transport Properties of Tetrabutylphosphonium Hydroxide and Tetrabutylphosphonium Chloride–Water Mixtures via Molecular Dynamics Simulation." Polymers 12, no. 1 (January 20, 2020): 249. http://dx.doi.org/10.3390/polym12010249.

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Thermodynamic, structural, and transport properties of tetrabutylphosphonium hydroxide (TBPH) and tetrabutylphosphonium chloride (TBPCl)–water mixtures have been investigated using all-atom molecular dynamics simulations in response to recent experimental work showing the TBPH–water mixtures capability as a cellulose solvent. Multiple transitional states exist for the water—ionic liquid (IL) mixture between 70 and 100 mol% water, which corresponds to a significant increase in water hydrogen bonds. The key transitional region, from 85 to 92.5 mol% water, which coincides with the mixture’s maximum cellulose solubility, reveals small and distinct water veins with cage structures formed by the TBP+ ions, while the hydroxide and chloride ions have moved away from the P atom of TBP+ and are strongly hydrogen bonded to the water. The maximum cellulose solubility of the TBPH–water solution at approximately 91.1 mol% water, appears correlated with the destruction of the TBP’s interlocking structure in the simulations, allowing the formation of water veins and channeling structures throughout the system, as well as changing from a subdiffusive to a near-normal diffusive regime, increasing the probability of the IL’s interaction with the cellulose polymer. A comparison is made between the solution properties of TBPH and TBPCl with those of alkylimidazolium-based ILs, for which water appears to act as anti-solvent rather than a co-solvent.

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Bogolitsyn, Konstantin Grigor'yevich, Evgeniya Anatol'yevna Moskalyuk, Nikolay Mikhaylovich Kostogorov, Elena Valer'yevna Shulginа, and Nikolay Leonidovich Ivanchenko. "APPLICATION OF INTEGRAL QUALITY INDICATORS OF WASTEWATERS FOR INPRODUCTION ECOLOGICAL AND ANALYTICAL CONTROL OF CELLULOSE PRODUCTION." chemistry of plant raw material, no. 2 (June 10, 2021): 343–52. http://dx.doi.org/10.14258/jcprm.2021027871.

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The influence of technological factors (wood species, degree of delignification, the technological regime of pulping) of cellulose semi-products production on composition and qualitative properties of wastewaters of pulp and paper mills following priority of harmonizing of technological and ecological rationing of industrial enterprises. The features of the biopolymer’s composition of the lignin-carbohydrate matrix of coniferous and deciduous species, its functional nature, and self-organization were provided. The main paths of chemical bond destruction in the lignin-carbohydrate complex during delignification and formation of the composition of organic fractions in local wastewaters were shown. The implementation of complementary indicators (COD, BOD5, general and organic carbon, the content of lignin, and volatile phenols) for in-house ecological and analytical control and rationing was substantiated. The dependence of integral indicator COD from the content of fractions of organic components from wastewaters was established. These components are products of destruction and chemical transformation of the lignin-carbohydrate matrix of deciduous and coniferous wood produced during delignification. The composition and the main phenolic components of wastewaters were determined by gas chromatography with mass detection. The correctness of worldwide practice of using "phenolic index" in the system of in-house control of pulp and paper mill was justified.

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Machado, Antonio Eduardo H., Jacques A. de Miranda, Renato F. de Freitas, Edward Thomas F. M. Duarte, Lucas F. Ferreira, Yaico D. T. Albuquerque, Reinaldo Ruggiero, Christian Sattler, and Lamark de Oliveira. "Destruction of the organic matter present in effluent from a cellulose and paper industry using photocatalysis." Journal of Photochemistry and Photobiology A: Chemistry 155, no. 1-3 (February 2003): 231–41. http://dx.doi.org/10.1016/s1010-6030(02)00393-3.

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35

Rogovina, S. Z., S. M. Lomakin, K. V. Aleksanyan, and E. V. Prut. "The structure, properties, and thermal destruction of biodegradable blends of cellulose and ethylcellulose with synthetic polymers." Russian Journal of Physical Chemistry B 6, no. 3 (May 2012): 416–24. http://dx.doi.org/10.1134/s1990793112060048.

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Mouzam, M. I., and M. H. G. Dehghan. "COMPARATIVE ASSESSMENT OF CHLORPHENIRAMINE MALEATE PERMEATION THROUGH CELLULOSE ACETATE MEMBRANE AND SHEEP NASAL MUCOSA." INDIAN DRUGS 51, no. 04 (April 28, 2014): 42–49. http://dx.doi.org/10.53879/id.51.04.p0042.

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The present research work was aimed to develop nasal mucoadhesive microspheres of chlorpheniramine maleate (CPM) & to compare its permeation rate through sheep nasal mucosa and cellulose acetate membrane. The impact of different concentrations of polymer and the dispersion media were evaluated for drug permeation, mucoadhesion, FT-IR and DSC studies. With the increase in polymer concentration, it was observed that the particle size and wall thickness of the microsphere increased; while the in-vitro drug permeation through sheep nasal mucosa significantly decreased when the volume of dispersion media was increased. Histopathological studies show the absence of epithelial cilia destruction. The permeation rate through sheep nasal mucosa was found to be 7.968 µg/hr/cm2, while through cellulose acetate (artificial) membrane showed 8.572 μg/hr/cm2. In conclusion, our results indicate that CPM released from chitosan microspheres penetrate well through sheep nasal mucosa, indicating suitability for nasal administration.

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Mouzam, M. I., and M. H. G. Dehghan. "COMPARATIVE ASSESSMENT OF CHLORPHENIRAMINE MALEATE PERMEATION THROUGH CELLULOSE ACETATE MEMBRANE AND SHEEP NASAL MUCOSA." INDIAN DRUGS 51, no. 04 (April 28, 2014): 42–49. http://dx.doi.org/10.53879/id.51.04.p0042.

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The present research work was aimed to develop nasal mucoadhesive microspheres of chlorpheniramine maleate (CPM) & to compare its permeation rate through sheep nasal mucosa and cellulose acetate membrane. The impact of different concentrations of polymer and the dispersion media were evaluated for drug permeation, mucoadhesion, FT-IR and DSC studies. With the increase in polymer concentration, it was observed that the particle size and wall thickness of the microsphere increased; while the in-vitro drug permeation through sheep nasal mucosa significantly decreased when the volume of dispersion media was increased. Histopathological studies show the absence of epithelial cilia destruction. The permeation rate through sheep nasal mucosa was found to be 7.968 µg/hr/cm2, while through cellulose acetate (artificial) membrane showed 8.572 μg/hr/cm2. In conclusion, our results indicate that CPM released from chitosan microspheres penetrate well through sheep nasal mucosa, indicating suitability for nasal administration.

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Gillespie, Richard, L. Keith Fifield, Vladimir Levchenko, and Rod Wells. "New 14C Ages on Cellulose from Diprotodon Gut Contents: Explorations in Oxidation Chemistry and Combustion." Radiocarbon 50, no. 1 (2008): 75–81. http://dx.doi.org/10.1017/s003382220004337x.

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We report radiocarbon ages on cellulose isolated from the gut contents of a Diprotodon found at Lake Callabonna, South Australia. The maximum age obtained corresponds to a minimum age of >53,400 BP for this extinct giant marsupial. This is older than, and hence consistent with, the generally accepted Australian megafauna extinction window. We argue that dichromate and other strong oxidants are less selective than chlorite for lignin destruction in wood, and our results suggest that ages approaching laboratory background can be obtained using a repeated pretreatment sequence of chlorite-alkali-acid and measurement of the sometimes discarded 330°C combustion fraction.

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39

Tağıyeva, Ü. Ə., X. Ə. ,. Əliyeva, L. Ə. ,. Əhmədova, and ,. Ş. R. Əliyeva. "CEYRANBATAN SU ANBARI SUYUNUN SANİTAR-KİMYƏVİ VƏ HİDROBİOLOJİ XÜSUSİYYƏTLƏRİ." “Water Problems: science and technologies” 1, no. 1 (June 10, 2021): 89–95. http://dx.doi.org/10.30546/wtst.2020.1.89.

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Abstract. The article presents fragments of the research with some sanitarychemical and hydrobiological characteristics of the water of the Jeyranbatan reservoir, which has an exceptional role in the production of water by the population of baku and Absheron region. At the same time, the commented materials contain information on the hydro-ecological condition of the water of the Jeyranbatan reservoir, which provides drinking water to about 65% of the population of the region. During the assessment of the aquatic environment in the samples taken in the spring of 2020, important indicators such as initial product and destruction parameters were identified. The research was conducted with methods widely used in international practice. Research has been carried out to develop practical recommendations for the study of saprophytic bacteria, which are considered autochthonous microbiota, as well as a number of physiological groups of azotobacter, phenol-absorbing, denitrating, cellulose-degrading bacteria and fungi in water samples. Key words: Jeyranbatan water reservoir, biogenic elements, production, destruction, autochthon, microbiota.

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Azarenko, Yu A., Zh L. Alekseeva, and N. V. Goman. "The effect of the solid fraction of pig manure on the biological activity of agrochernozem." IOP Conference Series: Earth and Environmental Science 954, no. 1 (January 1, 2022): 012007. http://dx.doi.org/10.1088/1755-1315/954/1/012007.

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Abstract The results of studies in 2016-2019 on the effect of the solid fraction of pig manure, applied at doses of 20-60 t/ha, on the indicators of the biological activity of the agrochernozem of loamy quasi-gley medium-arable medium with a low carbon content of organic matter (1.14-1.22%) are presented. The manure contained 0.59% of N, 1.13% of P2O5, 0.14% of K2O, 82.1% of organic matter at pH = 7.4. In field experiments carried out at the experimental field of the Omsk State Agrarian University (Omsk), the cellulose-destroying capacity of the soil and the activity of the enzymes catalase, urease and invertase were studied. The soil of the control variant had a weak cellulose-degrading capacity and was poor in the content of the studied enzymes. The results of the experiments indicate a positive effect of pig manure on the activity of biological processes in the soil. The cellulose-degrading capacity of agrochernozem depended on the dose of manure and the hydrothermal conditions of the growing season. In the period from the first to the third years of manure aftereffect, the intensity of cellulose destruction increased in comparison with the control by 20-90% at a dose of 20 t/ha and by 70-230% at a dose of 60 t/ha. Organic fertilization increased the activity of urease by 34.6-68.0%, by 10.7-14.6% that of catalase and by 5.8-12.2% that of invertase.

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Antonova, Natalia. "Development of Porous Films Based on Polyanionic Cellulose to Form Functional Coatings." Materials Science Forum 1049 (January 11, 2022): 130–37. http://dx.doi.org/10.4028/www.scientific.net/msf.1049.130.

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New porous films based on polyanionic cellulose with AlOOH nanoparticles have been developed. The morphology of the films has been studied by electron microscopy: the size of the formed pores is 1000-500 microns; the total surface porosity of the films is 30%. Using infrared microscopy, it was shown that during the formation of porous films, their chemical composition remains unchanged. Differential scanning calorimetry was used to determine the threshold for thermal destruction of porous films: 306 С. The possibility of using the obtained materials as antifriction coatings when filling the pores with solid lubricant MoS2 is considered. It is shown that for a steel sample protected by a porous coating with MoS2, the friction coefficient decreases by 50% compared to the friction coefficient for a steel surface under a load of up to 450 MPa.

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Vaniushenkova, Anna A., Elina E. Dosadina, Sergey V. Kalenov, Nikolay S. Markvichev, and Alexey A. Belov. "Synthesis and study of the properties of composite materials based on cellulose and chitosan containing various therapeutic agents. Part 2. Effect of chitosan on the destruction of cellulosic carriers and the kinetics of release of the therapeutic agent in the model environment." Butlerov Communications 57, no. 3 (March 31, 2019): 105–19. http://dx.doi.org/10.37952/roi-jbc-01/19-57-3-105.

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One of the important directions in the field of creation and research of medicines is the optimization of the therapeutic action of the active substance and the study of the interaction of the drug and its components with the body. Numerous studies have established that a modern wound-healing agent should have the following properties: to sorb purulent discharge and its destruction products, to have cleansing properties (usually due to the introduced proteolytic enzyme), to have biocidal properties (especially with respect to pathogenic microflora and first of all with respect to to Staphylococcus aureus), because wound infection can significantly slow down the healing process, and in some cases contribute to the transition of the wound process to a chronic one and include an antioxidant (especially for the treatment of long-term diseases). The degradation of high-molecular compounds in the body can be biological and non-biological. From the point of view of the destruction of biopolymers, degradation under the influence of external factors existing in the environment of a living organism is of particular interest. The mechanism for the release of a therapeutic agent into a wound occurs due to the destruction of the base and the rupture of various links between the therapeutic agents and the matrix during its use: hydrolytic destruction under the action of the body environment, as well as biological destruction due to the action of various biomolecules in the medium, mainly enzymes. On the basis of our own and literature data, schemes have been proposed for working in a model liquid medium of wound applications, based on dialdehydecellulose and chitosan, containing immobilized therapeutic agents, including enzymes. Chitosan has been shown to stabilize dialdehyde cellulose during hydrolytic degradation. Immobilization in chitosan gel, drying and storing various therapeutic agents and their mixtures in different directions affects the kinetics of drug release.

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Shirokikh, I. G., N. A. Bokov, and Ya I. Nazarova. "Impact of nitrogen sources in the nutrient medium on the growth and cellulase activity of streptomycetes." Proceedings of the Komi Science Centre of the Ural Division of the Russian Academy of Sciences 5 (2021): 61–65. http://dx.doi.org/10.19110/1994-5655-2021-5-61-65.

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Biomass accumulation and cellulase activity were determined in two promising soil isolates during liquid phase cultiva-tion depending on organic (peptone, casein hydrolysate) and mineral (NH4Cl, NaNO3, NH4NO3, (NH4)2SO4, KNO3) nitrogen sources. The only source of carbon in the medium was straw (1ob.%). Using two-factor analysis of variance, it was found that the production of cellulase complex enzymes is equally influenced by the nitrogen source (F= 225,92; p<0,0001), the producer strain (F=205,98; p<0,0001), the interaction of these factors (F=225,06; p< 0,0001). Inorganic nitrogen sources were the most preferred for cellulase production: NH4NO3 provided enzymatic activity in Streptomyces sp. Mb 4-2 is 912,82±60,40 units/10 min /g, and NH4Cl in Streptomyces sp. 1.3 NH4Cl is 531,37±27,25 units/10 min /g, which is 58–481 % and 34,5–409% more, respectively, than on other tested nitrogen sources. The accumulation of biomass during growth was more dependent on the nitrogen source (F= 65,47; p<0,0001) than on the strain of streptomycetes (F=18,65; p<0,0001). The interaction of these factors did not have a significant effect on the accumulation of biomass (F=1,11; p=0,38). Peptone and casein hyd-rolysate became the best nitrogen source for the growth of streptomycetes, providing an average of 19 % more biomass than inorganic nitrogen sources. It is shown that the optimization of the nutrient medium by the nitrogen source makes it possible to regulate the growth rates of streptomycetes-producing cultures and achieve maximum cellulase yield. The results obtained are of interest for the development of new environmentally friendly technological processes using streptomycetes in the production of cellulase complex enzymes and in the destruction of cellulose-containing agricultural waste.

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He, Feng, Dongye Zhao, and Chris Paul. "Field assessment of carboxymethyl cellulose stabilized iron nanoparticles for in situ destruction of chlorinated solvents in source zones." Water Research 44, no. 7 (April 2010): 2360–70. http://dx.doi.org/10.1016/j.watres.2009.12.041.

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Krampikowska, Aleksandra, and Anna Adamczak – Bugno. "Evaluation of destructive processes in FRC composites using time-frequency analysis of AE signals." MATEC Web of Conferences 262 (2019): 06006. http://dx.doi.org/10.1051/matecconf/201926206006.

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Modern fiber-cement boards currently used in construction are made of natural raw materials such as cement, cellulose fibers and of polyvinyl alcohol (PVA) and water. They replaced the eternitic plates, which were harmful to health, originated by Ludwig Hatschek. Materials made of fiber-cement are used in construction industry as a building and finishing material for facades, internal walls and roofs. Therefore, they are exposed to environmental conditions including rainfall and temperature changes, and in particular to frequent temperature transition through 0°C in a 24-hour cycle (cyclic freezing-thawing). In addition, fibrous cement materials, primarily used as cladding elements, are exposed to exceptional conditions, which include the high temperature caused by fire. The article presents the results of experimental tests of flexural strength of cement fiber boards subjected to exceptional conditions, to which the operation of fire belongs. The paper also presents a proposal to use a non-destructive method of acoustic emission based on time-frequency analysis for testing fiber-cement boards. Interesting research results were obtained that allowed to trace the differences in the mechanisms of material destruction under the influence of the changing time of external factors.

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Bruyako, Mihail Gerasimovich, and L. Grigoryeva. "Building Ecomaterials Based on Secondary Raw Material." Solid State Phenomena 284 (October 2018): 916–21. http://dx.doi.org/10.4028/www.scientific.net/ssp.284.916.

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Mineral raw natural resources are not unlimited. Preservation of such non-renewable resources is the most urgent task of mankind. The development of non-waste technologies, the integrated use of secondary raw materials, which simultaneously reduces environmental damage - one of the ways to solve environmental problems. Utilization of wastes makes it possible to solve issues of environmental protection as well as resource saving. In the light of environmental requirements, building materials based on recycled materials, including cellulose-containing solid waste, have significant advantages over other traditional materials. Development of technology for obtaining new effective environmentally safe composite highly filled materials based on cellulose-containing solid household waste for the production of construction products is a rational link in solving the general problem of improving the environmental situation. In the article there are three main ways of combining gypsum binder with cellulose-containing solid household waste. Investigations were carried out on the effect of changing the ratio of cardboard / gypsum binder, specific pressing pressure, sequence of combination of components on the properties of the final product. The strength of the material was determined from the values of the flexural strength, the compression to complete destruction of the sample, and at 10% deformation. Studies have been carried out to increase moisture resistance. The results showed that the most optimal way of combining is the 2 way. The increase in moisture resistance is significantly enhanced by the action of organosilicon hydrophobisers.

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Boufi, Sami, Soraa Bouattour, Ana Maria Ferraria, Luís Filipe Vieira Ferreira, Ana Maria Botelho do Rego, Mohamed M. Chehimi, and Manuel Rei Vilar. "Cotton fibres functionalized with plasmonic nanoparticles to promote the destruction of harmful molecules: an overview." Nanotechnology Reviews 8, no. 1 (December 31, 2019): 671–80. http://dx.doi.org/10.1515/ntrev-2019-0058.

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AbstractSelf-decontaminating cotton fabrics were designed, produced and characterized aiming at the decomposition of harmful molecules namely chemical warfare agents (CWAs) by photocatalysis under day light or indoor illumination. This was achieved through the creation of a hybrid organic-inorganic nanostructured textile composed of a thin layer of TiO2 nanoparticles (NPs) generated in situ and chemically immobilised on the cellulose chains of cotton fibres. TiO2 NPs were converted into anatase by a hydrothermal procedure at low temperature around 100°C. The fabrics covered with TiO2 nanoparticles were examined in terms of their chemical composition, morphology, crystallinity, ageing, robustness and photocatalytic properties. In the whole preparation of the photocatalytic fabrics, only environment-friendly solvents (water or alcohol) were used. One of the important achievements in this work was providing fabrics with suitable photocatalytic activity under visible light. This was reached through plasmonic photocatalysis by generating noble metal nanoparticles (Au, Ag) and/ or their halides (AgBr, AgCl) neighbouring or topping the TiO2 NPs in the fabrics. The kinetics of degradation of the different systems were analysed and proved that the resulting fabrics could efficiently decompose, under visible light, organic dyes and dimethyl methylphosphonate (DMMP), a CWA simulant.Graphical abstract

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Kharytonov, M. M., N. V. Martynova, A. V. Tokar, I. V. Rula, M. G. Babenko, and M. O. Bagorka. "SWEET SORGHUM BIOMASS QUANTITATIVE AND QUALITATIVE CHARACTERISTIC DEPENDING ON HYBRID AND TYPE OF SOIL." INMATEH Agricultural Engineering 59, no. 3 (December 20, 2019): 189–96. http://dx.doi.org/10.35633/inmateh-59-21.

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Ukrainian and American sweet sorghum hybrids were studied as raw material under reclaimed lands conditions in the southeast Ukraine. Among the cultivars in the range of hemicellulose destruction the highest reactivity was recorded for American hybrids, whereas the process of cellulose decomposition was most active in Ukrainian hybrids. Thermogravimetry (TG) curves of Ukrainian hybrids were more differed for plants grown on loess like loam comparative with American hybrids. The molecular structure of sweet sorghum lignin is represented by the spatially hindered hydroxyl groups of alcohol and phenolic type with the strength hydrogen bonding between some other structural fragments of macromolecules, ordinary carbon-oxygen bonds of metoxyl groups, and double carbon-carbon bonds.

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49

DAHLIG, WLODZIMIERZ, JANINA LUNKIEWICZ, TADEUSZ DIEM, and LESZEK MAKARUK. "Studies on the processes of cellulose nitrate destruction in solution. Part I. The effect of some physical and chemical agents on the viscosity reduction of cellulose nitrate solutions." Polimery 31, no. 05 (May 1986): 169–73. http://dx.doi.org/10.14314/polimery.1986.169.

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50

Ловинська, В. М., and І. В. Рула. "Аналіз термодеструкції компонентів стовбура сосни звичайної в умовах Північного Степу України." Вісник Полтавської державної аграрної академії, no. 3 (September 27, 2018): 39–44. http://dx.doi.org/10.31210/visnyk2018.03.06.

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Проведено дослідження процесу термодеструкції деревини і кори сосни звичайної в умовах північного байрачного Степу України. Методами термогравіметричного (TG), диференційно-термогравіметрич-ного (DTG) та диференційно-термічний (DTA) аналізів в окислювальному середовищі зі швидкістю нагріву 10 °С/хв здійснено якісний і кількісний аналіз та встановлено стадії термічного розкладання досліджуваних структурних компонентів стовбура. Отримано класичні криві, що описують процес термічного розкладання основних компонентів біомаси. Визначено основні температурні інтервали (етапів) процесів термоокислювальної деструкції. Розраховано енергію активації як в усьому досліджуваному діапазоні температур, так і для кожного із визначених етапів. Thermal decomposition of wood and bark from such coniferous species as Scots pine (Pinus sylvestris L.) within Northern Steppe of Ukraine has been studied using thermogravimetry (TG) and differential scanning calorimetry (DSC). Thermal qualitative and quantitative analysis of wood and bark samples was carried out in an oxidizing (air) atmosphere under conditions of a programmable heating up to 620 °C at heating rate 10 °C/min. The stages of thermal decomposition, the temperature intervals, the mass loss, the mass loss rate, the temperature peaks were determined for investigated species. The kinetic thermal degradation parameters of wood and bark were obtained by the Broido method. Scots pine wood and bark was characterized from the data of activation energy analysis at various stages of thermal decomposition. It is shown that the thermal decomposition process of pine wood and bark biomass is characterized by the behavior of the three main components of lignocellulosic biomass: hemo-cellulose, cellulose, and lignin. Four temperature ranges is identified, which characterize the basic stages of thermal decomposition of samples. The main process of thermo-oxidative degradation of cellulose in the bark began at a temperature ~ 220 °С, while for the wood – at ~ 240 °С. Less exothermic effect is observed for the bark at lower temperatures. There are two peaks on differential thermogravimetric curves of Scots pine wood and bark. The first was at a maximum at 320 °C for wood and 300 °C for bark, the second is at 440 °C for bark and 490 °C for wood, which correlates with the burning of coal. It was established that the activation energy values, that corresponding to the destruction process of the Scots pine trunk phytomass components in the studied temperature range were almost unchanged for wood and bark. But each of the destruction stages is characterized by different activation energy, which is well demonstrated by the peaks of differential thermogravimetric curves.

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Journal articles on the topic 'Destruction of cellulose'

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