Papers by Madina Shamsuyeva
Clean Technologies and Environmental Policy, Apr 18, 2023
The shells of walnuts (WS) are major refuse in the global fruits and nuts trade. This, otherwise ... more The shells of walnuts (WS) are major refuse in the global fruits and nuts trade. This, otherwise discarded, lignin-rich material can be carbonized to biochar-a value-added product with environmental applications such as carbon sequestration, soil amelioration, and pollutant adsorption. These applications are dictated by structural and chemical characteristics of the biochar carbon. Conventional controlled pyrolysis (CPy) of biomass is cost-intensive and technically too complex for widespread adoption, especially in emerging economies. Here, walnut shell biochar (BWS0) is derived through uncontrolled pyrolysis (UCPy) in a pyrolysis oven and further hybridized as magnetic biochar through ex-situ chemical co-precipitation. The physico-chemical characteristics of biochar and its water-extractable fractions are comprehensively investigated to understand their carbon structure and environmental applicability. The sp 2 amorphous carbon sequestered in BWS0 is 0.84 kg CO2 / kg biomass with a BET (N 2) surface area of 292 m 2 /g and is comparable to biochar from CPy in terms of carbon structure. The polyaromatic hydrocarbons present are only trace amounts of naphthalene, biphenyl, and phenanthrene. The magnetization decreases porosity of BWS0 while greatly facilitating its separation from aqueous media. BWS0 is suitable for adsorption of cations (between pH 2.8 and 9.45) and hydrophobic pollutants with only 19 mg L −1 fouling from their intrinsic dissolved organic carbon. In combination with fast-release N, P fertilizers, BWS0 (C/N of 24.8) is suitable for application in hydrophilic soils at higher loading rates. The results suggest an avenue where WS biochar can also be prepared via UCPy for direct environmental applications. Future investigations into soil incubation and adsorption tests are recommended.
RSC Advances
The sample mass during biomass pyrolysis in an thermogravimetric reactor is shown to influence th... more The sample mass during biomass pyrolysis in an thermogravimetric reactor is shown to influence the pyrolysis mechanism and properties of the resultant non-graphitizing carbon. There is an inflection mass scale beyond which this effect is minimal.
Sustainable Environment Research
The increase in mineral and ash-rich waste biomass (MWB) generation in emerging economies poses c... more The increase in mineral and ash-rich waste biomass (MWB) generation in emerging economies poses critical environmental problems and bottlenecks the solid waste and wastewater treatment systems. Transforming these MWB such as sewage sludge from wastewater treatment (SSW) to biochar can be a sustainable method for their disposal and resource recovery. However, such biochar has limited applicability due to the relatively low organic content and possibly contaminated nature of SSW. This may be offset through combined pyrolysis with other MWB, which can also support municipal solid waste management. Studies on this MWB co-pyrolysis are lacking and have not yet seen successful long-term implementation. This work is the second part of authors’ research encompassing an analytical and lab-scale investigation of biochar production from MWB through pyrolysis for the case of Chennai city, India. Here, the physicochemical properties of biochar derived from lab-scale co-pyrolysis of SSW with othe...
Clean Technologies and Environmental Policy
The shells of walnuts (WS) are major refuse in the global fruits and nuts trade. This, otherwise ... more The shells of walnuts (WS) are major refuse in the global fruits and nuts trade. This, otherwise discarded, lignin-rich material can be carbonized to biochar—a value-added product with environmental applications such as carbon sequestration, soil amelioration, and pollutant adsorption. These applications are dictated by structural and chemical characteristics of the biochar carbon. Conventional controlled pyrolysis (CPy) of biomass is cost-intensive and technically too complex for widespread adoption, especially in emerging economies. Here, walnut shell biochar (BWS0) is derived through uncontrolled pyrolysis (UCPy) in a pyrolysis oven and further hybridized as magnetic biochar through ex-situ chemical co-precipitation. The physico-chemical characteristics of biochar and its water-extractable fractions are comprehensively investigated to understand their carbon structure and environmental applicability. The sp2 amorphous carbon sequestered in BWS0 is 0.84 kgCO2/kgbiomass with a BET ...
Polymers, 2022
In various countries, polyethylene terephthalate (PET) represents one of the plastics with a very... more In various countries, polyethylene terephthalate (PET) represents one of the plastics with a very high recycling rate. Since currently there is no analytical method enabling direct distinction between recycled PET (rPET) and virgin PET (vPET), there are various attempts to differentiate these materials indirectly. One of these approaches claims that the recycling of PET leads to polymer chain degradation, which is reflected in changed thermal, mechanical and crystalline properties, and testing of these properties can therefore be used to distinguish rPET and vPET. However, there are many sources leading to changes in the molecular structure and consequently to the changes of the above-mentioned properties of the PET. The purpose of this study is to analyze the glass transition and melting temperature, degree of crystallinity as well as bending and impact properties of 20 different commercially available PET recyclates from 14 suppliers and evaluate the results with respect to the li...
Natural fiber-reinforced polymer composites have already been successfully established in various... more Natural fiber-reinforced polymer composites have already been successfully established in various lightweight applications subjected to moderate mechanical stress, e.g. automotive interior. Recently, the development of biobased hybrid composites containing both, natural and high-performance fibers, gained the attention of research institutions and industry. These new composites offer optimized density, mechanical performance, have reasonable cost and low environmental impact. The bio hybrid composites enable utilization of the advantages of cellulose-based and high-performance fibers in the same composite and minimize the limitations of the individual composites. Although this approach seems to be a promising solution for several drawbacks, the deficiency of the approaches to improve the durability of these composites in outdoor applications limits their market penetration.
Composites Part C: Open Access, 2021
Materials Today: Proceedings, 2020
This feasibility study investigates the mechanical properties of novel hybrid biocomposites for l... more This feasibility study investigates the mechanical properties of novel hybrid biocomposites for lightweight applications, which include high content of components based on renewable feedstock and at the same time show high mechanical performance. In contrast to established synthetic hybrid composites containing different types of synthetic fibers in a one composite, this is a combination of synthetic high-performance fibers with natural fibers in one reinforcing textile manufactured using a weaving technique. The investigated bio-hybrid woven textiles contain a combination of flax with glass or carbon fibers. In this study the bending properties of the bio-hybrid textile composites are evaluated in comparison with biocomposites containing merely flax textiles. The biocomposites are manufactured by embedding the hybrid fabrics into a bio-based epoxy matrix. The results show that the use of the hybrid woven textiles with a mass fraction of natural fibers corresponding to 50% enables manufacture of biocomposites with significantly higher bending properties compared with flax fiber-reinforced biocomposites. Furthermore, the achieved values are comparable with those of the sandwich-structured hybrid biocomposites.
International Journal of Polymer Science, 2019
Numerous research studies are carried out in order to investigate various properties and implemen... more Numerous research studies are carried out in order to investigate various properties and implement the potential of hybrid carbon/flax composites for technical applications. This review aims to present a summary of materials and manufacturing techniques, which are currently used for the fabrication of the carbon/flax composites, and describe the reported tensile, bending, impact, and damping properties of the resulting hybrid materials as well as the attempts to model some of these properties.
Key Engineering Materials, 2019
An effective integration of natural fibers into engineering thermoplastics requires sufficient th... more An effective integration of natural fibers into engineering thermoplastics requires sufficient thermal stability of natural fibers during processing, since melting temperature of engineering thermoplastics lies above 200 °C. The aim of the work was to protect natural fibers from the heat of the molten thermoplastic via coating with a modified epoxy resin, thus enabling manufacture of natural fiber-reinforced engineering thermoplastic composites with minimized thermal degradation of the fibers. Processing temperature comprised the range of engineering thermoplastic polyamide 6 (PA6), which was 225 °C. Flax fabrics were spray coated with partially bio-based epoxy resin and incorporated via hot press technique into a PA6 matrix. The composite samples including spray coated flax fibers as well as the reference flax fibers without coating were characterized with regard to their mechanical properties, namely bending and tensile tests, thermal properties with differential scanning calorime...
Journal of Composites Science, 2019
This feasibility study investigates the flexural properties of biocomposites containing woven fla... more This feasibility study investigates the flexural properties of biocomposites containing woven flax textiles (plain, twill, satin) and woven twill patterned hybrid textiles containing flax-/glass or flax-/carbon mixture for lightweight applications. Synthetic fibers are integrated as weft and flax fibers are integrated as warp yarns using a double-rapier weaving machine with a Jacquard attachment. The corresponding biocomposites are manufactured via vacuum infusion process using a biobased epoxy resin as a matrix. The manufactured biocomposites are analyzed with regard to their density and flexural properties. The results show that the use of hybrid textiles offers a promising solution for the manufacture of biocomposites with a higher biobased content and significantly improved flexural properties. Furthermore, the introduction of high-performance synthetic fibers in textiles enables the manufacture of biocomposites with an isotropic mechanical performance.
Key Engineering Materials, 2017
In this study flax fabrics were treated with polyethylene imine (PEI) and afterwards, in combinat... more In this study flax fabrics were treated with polyethylene imine (PEI) and afterwards, in combination with carbon fabrics, integrated into epoxy resin via vacuum infusion process. The influence of the 2 stacking sequences of the fabrics and 2 PEI concentrations were evaluated with regard to the mass fractions of the composite components and mechanical properties of the manufactured composites, namely, flexural and interlaminar shear properties. The results showed that the effect of the surface treatment is dependent on the stacking sequence. Namely, increase of the PEI concentration resulted in a corresponding increase of the mass fraction of the polymer matrix in the case of interchanging arrangement of flax and carbon fabrics. Further remarkable results showed that the same specimen provided the highest values of the supported maximum load after the surface treatment. Influence of the PEI treatment on the strength values with regard to the stacking sequence and polyelectrolyte conc...
Composites Part C: Open Access, 2021
Journal of Composites Science
The aim of this feasibility study is to develop application-oriented natural fiber-reinforced bio... more The aim of this feasibility study is to develop application-oriented natural fiber-reinforced biocomposites with improved mechanical and durability performance. The biocomposites were manufactured via a film-stacking process of epoxy-coated flax textiles and polyamide 6 (PA6). The fabricated biocomposites were subjected to thermo-oxidative ageing for 250, 500 and 1000 h and tested with regard to tensile properties. The results show that the biocomposites with epoxy-coated flax fibers possess considerably higher tensile properties compared with the reference specimens under all tested conditions.
Journal of Materials Science: Materials in Electronics
The aim of this work was to create a biocomposite material with controllable electrical resistanc... more The aim of this work was to create a biocomposite material with controllable electrical resistance for lightweight engineering made from regenerated cellulose-based fibers and a partially biobased epoxy resin. In this feasibility study viscose fabrics were coated with polypyrrole (PPy) by in situ polymerization of pyrrole (Py) and iron(III)-chloride as an oxidizing agent for the insertion of an electrical conductivity. Para-toluene sulfonic acid (pTSA) and 9,10-anthraquinone-2,6-disulfonic acid disodium salt (AQSA) were used as dopant agents to induce the conductivity. The treated viscose fabrics were incorporated into an epoxy matrix via vacuum infusion process and the resulting biocomposites were afterwards analyzed by electrical four-point measurement and three-point bending test. The surface of the coated fibers and the fracture surface after the bending test were analyzed via scanning electron microscopy (SEM). Through varying the pyrrole concentration between 3 and 6 g/l and the oxidizing/dopant agent ratio between 2:1 and 2:4, a significant reduction of electrical resistance was obtained. The lowest electrical resistance, 50 Ω/sq by the coated viscose fabrics and 7 Ω/sq by the corresponding biocomposites, was achieved by using the dopant/oxidizing ratio of 2:2. These results showed that the coating with pyrrole is a promising approach for the manufacture of electrically conductive biocomposite materials.
Academic Journal of Polymer Science
In the scope of this study woven flax fibers are coated with aqueous polyethyleneimine (PEI) solu... more In the scope of this study woven flax fibers are coated with aqueous polyethyleneimine (PEI) solution, in order to improve the bending properties of the produced flax fiber-reinforced epoxy composite. The textiles are coated with the different concentrations of PEI solution and integrated into the biobased epoxy using hand impregnation with subsequent hot-press. The results show that 1 wt% and 5 wt% PEI can considerably improve the bending properties of the tested biocomposites.
In this study flax fabrics were treated with polyethylene imine (PEI) and afterwards, in combinat... more In this study flax fabrics were treated with polyethylene imine (PEI) and afterwards, in combination with carbon fabrics, integrated into epoxy resin via vacuum infusion process. The influence of the 2 stacking sequences of the fabrics and 2 PEI concentrations were evaluated with regard to the mass fractions of the composite components and mechanical properties of the manufactured composites, namely, flexural and interlaminar shear properties. The results showed that the effect of the surface treatment is dependent on the stacking sequence. Namely, increase of the PEI concentration resulted in a corresponding increase of the mass fraction of the polymer matrix in the case of interchanging arrangement of flax and carbon fabrics. Further remarkable results showed that the same specimen provided the highest values of the supported maximum load after the surface treatment. Influence of the PEI treatment on the strength values with regard to the stacking sequence and polyelectrolyte concentration led to controversial results. Decrease of flexural modulus after the surface treatment was observed in the case of all samples.
Natural fiber-reinforced polymer composites have already been successfully established in various... more Natural fiber-reinforced polymer composites have already been successfully established in various lightweight applications subjected to moderate mechanical stress, e.g. automotive interior. Recently, the development of biobased hybrid composites containing both, natural and high-performance fibers, gained the attention of research institutions and industry. These new composites offer optimized density, mechanical performance, have reasonable cost and low environmental impact. The bio hybrid composites enable utilization of the advantages of cellulose-based and high-performance fibers in the same composite and minimize the limitations of the individual composites. Although this approach seems to be a promising solution for several drawbacks, the deficiency of the approaches to improve the durability of these composites in outdoor applications limits their market penetration.
In this project, a specially developed plasma treatment approach, cascade-atmospheric pressure plasma is being adapted in order to improve the mechanical performance of the biobased (hybrid) composites for the application-oriented use under various environmental conditions, e.g. high humidity absorption and temperature variance. This study presents selected results of this project including the assessment of the plasma treatment of multi-ply textiles and the corresponding influence on the mechanical performance of the composites. UD flax tapes and balanced, more isotropic flax fabrics were treated under various plasma parameters and integrated into a partially biobased epoxy resin via vacuum infusion. The analysis of the textile surface and composite mechanical properties were used for the assessment. It has become evident that the selection of the plasma parameters has a significant effect on the packing density and wettability of the treated textiles. Controversial effects have been observed with regard to the mechanical properties of the composites. An improvement of weathering durability is still remaining.
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Papers by Madina Shamsuyeva
In this project, a specially developed plasma treatment approach, cascade-atmospheric pressure plasma is being adapted in order to improve the mechanical performance of the biobased (hybrid) composites for the application-oriented use under various environmental conditions, e.g. high humidity absorption and temperature variance. This study presents selected results of this project including the assessment of the plasma treatment of multi-ply textiles and the corresponding influence on the mechanical performance of the composites. UD flax tapes and balanced, more isotropic flax fabrics were treated under various plasma parameters and integrated into a partially biobased epoxy resin via vacuum infusion. The analysis of the textile surface and composite mechanical properties were used for the assessment. It has become evident that the selection of the plasma parameters has a significant effect on the packing density and wettability of the treated textiles. Controversial effects have been observed with regard to the mechanical properties of the composites. An improvement of weathering durability is still remaining.
In this project, a specially developed plasma treatment approach, cascade-atmospheric pressure plasma is being adapted in order to improve the mechanical performance of the biobased (hybrid) composites for the application-oriented use under various environmental conditions, e.g. high humidity absorption and temperature variance. This study presents selected results of this project including the assessment of the plasma treatment of multi-ply textiles and the corresponding influence on the mechanical performance of the composites. UD flax tapes and balanced, more isotropic flax fabrics were treated under various plasma parameters and integrated into a partially biobased epoxy resin via vacuum infusion. The analysis of the textile surface and composite mechanical properties were used for the assessment. It has become evident that the selection of the plasma parameters has a significant effect on the packing density and wettability of the treated textiles. Controversial effects have been observed with regard to the mechanical properties of the composites. An improvement of weathering durability is still remaining.