B. Lesbayev, Nurgali Rakhymzhan, Gaukhar Ustayeva, Yerkebulan Maral, M. Atamanov, Moldir Auyelkhankyzy, Ayazhan Zhamash
This study proposes a method to control the pore-forming process by performing preliminary mechanical activation of the initial rice husk before carbonization. Preliminary mechanical activation of the initial rice husk leads to the loosening of the intercellular substance and its partial depolymerization, thereby increasing the availability of its internal structure for pore formation during carbonization and chemical activation. Using the method described above, nanoporous carbon was obtained with a Brunauer–Emmett–Teller (BET)-calculated specific surface area of 2713 m2/g, a micropore specific surface area calculated by using the Dubinina–Radushkevich (D-R) method of 3099 m2/g, and a total pore volume calculated by using the Barett–Joyner–Halenda (BJH) method of 1.625 cm3/g. Due to these characteristics, the adsorption capacity in the obtained sample was for hydrogen 3.7 wt.% at a temperature of −190 °C and a pressure of 9 kgf/cm2, which is 29.7% higher than the adsorption capacity of nanoporous carbon obtained based on rice husk without mechanical activation. The composite “carbon–platinum” NC-2/Pt10%, at a temperature of 20 °C and a pressure of 9 kgf/cm2, showed an increase in sorption capacity of 27% compared to pure nanoporous carbon NC-2, which is explained by the emergence of the spillover effect.
{"title":"Preparation of Nanoporous Carbon from Rice Husk with Improved Textural Characteristics for Hydrogen Sorption","authors":"B. Lesbayev, Nurgali Rakhymzhan, Gaukhar Ustayeva, Yerkebulan Maral, M. Atamanov, Moldir Auyelkhankyzy, Ayazhan Zhamash","doi":"10.3390/jcs8020074","DOIUrl":"https://doi.org/10.3390/jcs8020074","url":null,"abstract":"This study proposes a method to control the pore-forming process by performing preliminary mechanical activation of the initial rice husk before carbonization. Preliminary mechanical activation of the initial rice husk leads to the loosening of the intercellular substance and its partial depolymerization, thereby increasing the availability of its internal structure for pore formation during carbonization and chemical activation. Using the method described above, nanoporous carbon was obtained with a Brunauer–Emmett–Teller (BET)-calculated specific surface area of 2713 m2/g, a micropore specific surface area calculated by using the Dubinina–Radushkevich (D-R) method of 3099 m2/g, and a total pore volume calculated by using the Barett–Joyner–Halenda (BJH) method of 1.625 cm3/g. Due to these characteristics, the adsorption capacity in the obtained sample was for hydrogen 3.7 wt.% at a temperature of −190 °C and a pressure of 9 kgf/cm2, which is 29.7% higher than the adsorption capacity of nanoporous carbon obtained based on rice husk without mechanical activation. The composite “carbon–platinum” NC-2/Pt10%, at a temperature of 20 °C and a pressure of 9 kgf/cm2, showed an increase in sorption capacity of 27% compared to pure nanoporous carbon NC-2, which is explained by the emergence of the spillover effect.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"18 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139845684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sergey V. Yudintsev, Michael I. Ojovan, V. Malkovsky
The current policy of managing high-level waste (HLW) derived in the closed nuclear fuel cycle consists in their vitrification into B-Si or Al-P vitreous forms. These compounds have rather limited capacity with respect to the HLW (5–20 wt%), and their properties change over time due to devitrification of the glasses. Cardinal improvement in the management of HLW can be achieved by their separation onto groups of elements with similar properties, followed by their immobilization in robust waste forms (matrices) and emplacement in deep disposal facilities. One of the possible fractions contains trivalent rare-earth elements (REEs) and minor actinides (MAs = Am and Cm). REEs are the fission products of actinides, which are mainly represented by stable isotopes of elements from La to Gd as well as Y. This group also contains small amounts of short-lived radionuclides with half-lives (T1/2) from 284 days (144Ce) to 90 years (151Sm), including 147Pm (T1/2 = 2.6 years), 154Eu (T1/2 = 8.8 years), and 155Eu (T1/2 = 5 years). However, the main long-term environmental hazard of the REE–MA fraction is associated with Am and Cm, with half-lives from 18 years (244Cm) to 8500 years (245Cm), and their daughter products: 237Np (T1/2 = 2.14 × 106 years), 239Pu (T1/2 = 2.41 × 104 years), 240Pu (T1/2 = 6537 years), and 242Pu (T1/2 = 3.76 × 105 years), which should be immobilized into a durable waste form that prevents their release into the environment. Due to the heat generated by decaying radionuclides, the temperature of matrices with an REE–MA fraction will be increased by hundreds of centigrade above ambient. This process can be utilized by selecting a vitreous waste form that will crystallize to form durable crystalline phases with long-lived radionuclides. We estimated the thermal effects in a potential REE–MA glass composite material based on the size of the block, the content of waste, the time of storage before immobilization and after disposal, and showed that it is possible to select the waste loading, size of blocks, and storage time so that the temperature of the matrix during the first decades will reach 500–700 °C, which corresponds to the optimal range of glass crystallization. As a result, a glass–ceramic composite will be produced that contains monazite ((REE,MA)PO4) in phosphate glasses; britholite (Cax(REE,MA)10-x(SiO4)6O2) or zirconolite ((Ca,REE,MA)(Zr,REE,MA)(Ti,Al,Fe)2O7), in silicate systems. This possibility is confirmed by experimental data on the crystallization of glasses with REEs and actinides (Pu, Am). The prospect for the disposal of glasses with the REE–MA fraction in deep boreholes is briefly considered.
{"title":"Thermal Effects and Glass Crystallization in Composite Matrices for Immobilization of the Rare-Earth Element–Minor Actinide Fraction of High-Level Radioactive Waste","authors":"Sergey V. Yudintsev, Michael I. Ojovan, V. Malkovsky","doi":"10.3390/jcs8020070","DOIUrl":"https://doi.org/10.3390/jcs8020070","url":null,"abstract":"The current policy of managing high-level waste (HLW) derived in the closed nuclear fuel cycle consists in their vitrification into B-Si or Al-P vitreous forms. These compounds have rather limited capacity with respect to the HLW (5–20 wt%), and their properties change over time due to devitrification of the glasses. Cardinal improvement in the management of HLW can be achieved by their separation onto groups of elements with similar properties, followed by their immobilization in robust waste forms (matrices) and emplacement in deep disposal facilities. One of the possible fractions contains trivalent rare-earth elements (REEs) and minor actinides (MAs = Am and Cm). REEs are the fission products of actinides, which are mainly represented by stable isotopes of elements from La to Gd as well as Y. This group also contains small amounts of short-lived radionuclides with half-lives (T1/2) from 284 days (144Ce) to 90 years (151Sm), including 147Pm (T1/2 = 2.6 years), 154Eu (T1/2 = 8.8 years), and 155Eu (T1/2 = 5 years). However, the main long-term environmental hazard of the REE–MA fraction is associated with Am and Cm, with half-lives from 18 years (244Cm) to 8500 years (245Cm), and their daughter products: 237Np (T1/2 = 2.14 × 106 years), 239Pu (T1/2 = 2.41 × 104 years), 240Pu (T1/2 = 6537 years), and 242Pu (T1/2 = 3.76 × 105 years), which should be immobilized into a durable waste form that prevents their release into the environment. Due to the heat generated by decaying radionuclides, the temperature of matrices with an REE–MA fraction will be increased by hundreds of centigrade above ambient. This process can be utilized by selecting a vitreous waste form that will crystallize to form durable crystalline phases with long-lived radionuclides. We estimated the thermal effects in a potential REE–MA glass composite material based on the size of the block, the content of waste, the time of storage before immobilization and after disposal, and showed that it is possible to select the waste loading, size of blocks, and storage time so that the temperature of the matrix during the first decades will reach 500–700 °C, which corresponds to the optimal range of glass crystallization. As a result, a glass–ceramic composite will be produced that contains monazite ((REE,MA)PO4) in phosphate glasses; britholite (Cax(REE,MA)10-x(SiO4)6O2) or zirconolite ((Ca,REE,MA)(Zr,REE,MA)(Ti,Al,Fe)2O7), in silicate systems. This possibility is confirmed by experimental data on the crystallization of glasses with REEs and actinides (Pu, Am). The prospect for the disposal of glasses with the REE–MA fraction in deep boreholes is briefly considered.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139786845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruiqi Zheng, Jianyong Pang, Jian Sun, Yongqiang Su, Guoping Xu
In order to enhance the practical application of carbon-fiber-reinforced concrete (CFRC) in engineering, it is necessary to study the damage mechanism of CFRC. Experimental research on the mechanical properties of CFRC under multiple strain rates was conducted. Five different fiber contents were analyzed to study the compressive strength and tensile strength of CFRC, and the damage characteristics of CFRC under multiple strain rates were analyzed based on failure modes and energy changes. An energy-based damage constitutive model was established. The results showed the following: (1) When the carbon fiber content was 0.4%, CFRC had the best comprehensive performance, with a 15.02% increase in compressive strength and a 51.12% increase in tensile strength. With the increase in strain rate, the compressive strength of the concrete increased. (2) Under high strain rates, carbon fiber significantly enhanced the compressive strength of the concrete, and the input energy, elastic strain energy, and dissipated energy increased. The peak value of the elastic strain energy conversion rate increased, and the minimum value of the dissipated energy conversion rate decreased. (3) Under the same strain rate, the CFRC had a larger inflection point of dissipated energy corresponding to the strain compared to the reference group of concrete during the loading process. A constitutive model for CFRC was established based on damage mechanics and probability statistics. The research results will provide theoretical references for the application of carbon-fiber-reinforced concrete.
{"title":"Damage Model of Carbon-Fiber-Reinforced Concrete Based on Energy Conversion Principle","authors":"Ruiqi Zheng, Jianyong Pang, Jian Sun, Yongqiang Su, Guoping Xu","doi":"10.3390/jcs8020071","DOIUrl":"https://doi.org/10.3390/jcs8020071","url":null,"abstract":"In order to enhance the practical application of carbon-fiber-reinforced concrete (CFRC) in engineering, it is necessary to study the damage mechanism of CFRC. Experimental research on the mechanical properties of CFRC under multiple strain rates was conducted. Five different fiber contents were analyzed to study the compressive strength and tensile strength of CFRC, and the damage characteristics of CFRC under multiple strain rates were analyzed based on failure modes and energy changes. An energy-based damage constitutive model was established. The results showed the following: (1) When the carbon fiber content was 0.4%, CFRC had the best comprehensive performance, with a 15.02% increase in compressive strength and a 51.12% increase in tensile strength. With the increase in strain rate, the compressive strength of the concrete increased. (2) Under high strain rates, carbon fiber significantly enhanced the compressive strength of the concrete, and the input energy, elastic strain energy, and dissipated energy increased. The peak value of the elastic strain energy conversion rate increased, and the minimum value of the dissipated energy conversion rate decreased. (3) Under the same strain rate, the CFRC had a larger inflection point of dissipated energy corresponding to the strain compared to the reference group of concrete during the loading process. A constitutive model for CFRC was established based on damage mechanics and probability statistics. The research results will provide theoretical references for the application of carbon-fiber-reinforced concrete.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" April","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139787347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sergey V. Yudintsev, Michael I. Ojovan, V. Malkovsky
The current policy of managing high-level waste (HLW) derived in the closed nuclear fuel cycle consists in their vitrification into B-Si or Al-P vitreous forms. These compounds have rather limited capacity with respect to the HLW (5–20 wt%), and their properties change over time due to devitrification of the glasses. Cardinal improvement in the management of HLW can be achieved by their separation onto groups of elements with similar properties, followed by their immobilization in robust waste forms (matrices) and emplacement in deep disposal facilities. One of the possible fractions contains trivalent rare-earth elements (REEs) and minor actinides (MAs = Am and Cm). REEs are the fission products of actinides, which are mainly represented by stable isotopes of elements from La to Gd as well as Y. This group also contains small amounts of short-lived radionuclides with half-lives (T1/2) from 284 days (144Ce) to 90 years (151Sm), including 147Pm (T1/2 = 2.6 years), 154Eu (T1/2 = 8.8 years), and 155Eu (T1/2 = 5 years). However, the main long-term environmental hazard of the REE–MA fraction is associated with Am and Cm, with half-lives from 18 years (244Cm) to 8500 years (245Cm), and their daughter products: 237Np (T1/2 = 2.14 × 106 years), 239Pu (T1/2 = 2.41 × 104 years), 240Pu (T1/2 = 6537 years), and 242Pu (T1/2 = 3.76 × 105 years), which should be immobilized into a durable waste form that prevents their release into the environment. Due to the heat generated by decaying radionuclides, the temperature of matrices with an REE–MA fraction will be increased by hundreds of centigrade above ambient. This process can be utilized by selecting a vitreous waste form that will crystallize to form durable crystalline phases with long-lived radionuclides. We estimated the thermal effects in a potential REE–MA glass composite material based on the size of the block, the content of waste, the time of storage before immobilization and after disposal, and showed that it is possible to select the waste loading, size of blocks, and storage time so that the temperature of the matrix during the first decades will reach 500–700 °C, which corresponds to the optimal range of glass crystallization. As a result, a glass–ceramic composite will be produced that contains monazite ((REE,MA)PO4) in phosphate glasses; britholite (Cax(REE,MA)10-x(SiO4)6O2) or zirconolite ((Ca,REE,MA)(Zr,REE,MA)(Ti,Al,Fe)2O7), in silicate systems. This possibility is confirmed by experimental data on the crystallization of glasses with REEs and actinides (Pu, Am). The prospect for the disposal of glasses with the REE–MA fraction in deep boreholes is briefly considered.
{"title":"Thermal Effects and Glass Crystallization in Composite Matrices for Immobilization of the Rare-Earth Element–Minor Actinide Fraction of High-Level Radioactive Waste","authors":"Sergey V. Yudintsev, Michael I. Ojovan, V. Malkovsky","doi":"10.3390/jcs8020070","DOIUrl":"https://doi.org/10.3390/jcs8020070","url":null,"abstract":"The current policy of managing high-level waste (HLW) derived in the closed nuclear fuel cycle consists in their vitrification into B-Si or Al-P vitreous forms. These compounds have rather limited capacity with respect to the HLW (5–20 wt%), and their properties change over time due to devitrification of the glasses. Cardinal improvement in the management of HLW can be achieved by their separation onto groups of elements with similar properties, followed by their immobilization in robust waste forms (matrices) and emplacement in deep disposal facilities. One of the possible fractions contains trivalent rare-earth elements (REEs) and minor actinides (MAs = Am and Cm). REEs are the fission products of actinides, which are mainly represented by stable isotopes of elements from La to Gd as well as Y. This group also contains small amounts of short-lived radionuclides with half-lives (T1/2) from 284 days (144Ce) to 90 years (151Sm), including 147Pm (T1/2 = 2.6 years), 154Eu (T1/2 = 8.8 years), and 155Eu (T1/2 = 5 years). However, the main long-term environmental hazard of the REE–MA fraction is associated with Am and Cm, with half-lives from 18 years (244Cm) to 8500 years (245Cm), and their daughter products: 237Np (T1/2 = 2.14 × 106 years), 239Pu (T1/2 = 2.41 × 104 years), 240Pu (T1/2 = 6537 years), and 242Pu (T1/2 = 3.76 × 105 years), which should be immobilized into a durable waste form that prevents their release into the environment. Due to the heat generated by decaying radionuclides, the temperature of matrices with an REE–MA fraction will be increased by hundreds of centigrade above ambient. This process can be utilized by selecting a vitreous waste form that will crystallize to form durable crystalline phases with long-lived radionuclides. We estimated the thermal effects in a potential REE–MA glass composite material based on the size of the block, the content of waste, the time of storage before immobilization and after disposal, and showed that it is possible to select the waste loading, size of blocks, and storage time so that the temperature of the matrix during the first decades will reach 500–700 °C, which corresponds to the optimal range of glass crystallization. As a result, a glass–ceramic composite will be produced that contains monazite ((REE,MA)PO4) in phosphate glasses; britholite (Cax(REE,MA)10-x(SiO4)6O2) or zirconolite ((Ca,REE,MA)(Zr,REE,MA)(Ti,Al,Fe)2O7), in silicate systems. This possibility is confirmed by experimental data on the crystallization of glasses with REEs and actinides (Pu, Am). The prospect for the disposal of glasses with the REE–MA fraction in deep boreholes is briefly considered.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"23 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139846679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruiqi Zheng, Jianyong Pang, Jian Sun, Yongqiang Su, Guoping Xu
In order to enhance the practical application of carbon-fiber-reinforced concrete (CFRC) in engineering, it is necessary to study the damage mechanism of CFRC. Experimental research on the mechanical properties of CFRC under multiple strain rates was conducted. Five different fiber contents were analyzed to study the compressive strength and tensile strength of CFRC, and the damage characteristics of CFRC under multiple strain rates were analyzed based on failure modes and energy changes. An energy-based damage constitutive model was established. The results showed the following: (1) When the carbon fiber content was 0.4%, CFRC had the best comprehensive performance, with a 15.02% increase in compressive strength and a 51.12% increase in tensile strength. With the increase in strain rate, the compressive strength of the concrete increased. (2) Under high strain rates, carbon fiber significantly enhanced the compressive strength of the concrete, and the input energy, elastic strain energy, and dissipated energy increased. The peak value of the elastic strain energy conversion rate increased, and the minimum value of the dissipated energy conversion rate decreased. (3) Under the same strain rate, the CFRC had a larger inflection point of dissipated energy corresponding to the strain compared to the reference group of concrete during the loading process. A constitutive model for CFRC was established based on damage mechanics and probability statistics. The research results will provide theoretical references for the application of carbon-fiber-reinforced concrete.
{"title":"Damage Model of Carbon-Fiber-Reinforced Concrete Based on Energy Conversion Principle","authors":"Ruiqi Zheng, Jianyong Pang, Jian Sun, Yongqiang Su, Guoping Xu","doi":"10.3390/jcs8020071","DOIUrl":"https://doi.org/10.3390/jcs8020071","url":null,"abstract":"In order to enhance the practical application of carbon-fiber-reinforced concrete (CFRC) in engineering, it is necessary to study the damage mechanism of CFRC. Experimental research on the mechanical properties of CFRC under multiple strain rates was conducted. Five different fiber contents were analyzed to study the compressive strength and tensile strength of CFRC, and the damage characteristics of CFRC under multiple strain rates were analyzed based on failure modes and energy changes. An energy-based damage constitutive model was established. The results showed the following: (1) When the carbon fiber content was 0.4%, CFRC had the best comprehensive performance, with a 15.02% increase in compressive strength and a 51.12% increase in tensile strength. With the increase in strain rate, the compressive strength of the concrete increased. (2) Under high strain rates, carbon fiber significantly enhanced the compressive strength of the concrete, and the input energy, elastic strain energy, and dissipated energy increased. The peak value of the elastic strain energy conversion rate increased, and the minimum value of the dissipated energy conversion rate decreased. (3) Under the same strain rate, the CFRC had a larger inflection point of dissipated energy corresponding to the strain compared to the reference group of concrete during the loading process. A constitutive model for CFRC was established based on damage mechanics and probability statistics. The research results will provide theoretical references for the application of carbon-fiber-reinforced concrete.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"230 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139847482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Victor Hugo M. Almeida, Raildo M. Jesus, G. M. Santana, Thaís B. Pereira
The escalating global demand for polymer products and the consequent disposal challenge necessitate technological and sustainable solutions. Recent advances in the development of materials used in 3D printing equipment are described in this review, with a focus on new biocomposite materials. The investigation delves into biocomposites comprising PLA and its blends with other polymers, reinforced by plant fibers, with a particular focus on research conducted over the last five years. The information related to the raw materials’ physical, chemical, and processing properties necessary for creating biocomposite filament and printed parts were summarized. The best results in terms of tensile and flexural strength were presented and discussed, signposting future research avenues and desirable objectives. The findings elucidate that the inclusion of plant fibers led to a reduction in mechanical strength relative to pure PLA; however, when smaller particle sizes of plant fibers were added in volumes below 10%, it resulted in improved performance. Moreover, physical and/or chemical pretreatment of fibers, along with the isolation of cellulose fibrils, emerged as pivotal strategies for bolstering mechanical strengths. Noteworthy are the promising prospects presented by the incorporation of additives, while the refinement of printing parameters is key to improving the tensile and flexural strength of printed components.
{"title":"Polylactic Acid Polymer Matrix (Pla) Biocomposites with Plant Fibers for Manufacturing 3D Printing Filaments: A Review","authors":"Victor Hugo M. Almeida, Raildo M. Jesus, G. M. Santana, Thaís B. Pereira","doi":"10.3390/jcs8020067","DOIUrl":"https://doi.org/10.3390/jcs8020067","url":null,"abstract":"The escalating global demand for polymer products and the consequent disposal challenge necessitate technological and sustainable solutions. Recent advances in the development of materials used in 3D printing equipment are described in this review, with a focus on new biocomposite materials. The investigation delves into biocomposites comprising PLA and its blends with other polymers, reinforced by plant fibers, with a particular focus on research conducted over the last five years. The information related to the raw materials’ physical, chemical, and processing properties necessary for creating biocomposite filament and printed parts were summarized. The best results in terms of tensile and flexural strength were presented and discussed, signposting future research avenues and desirable objectives. The findings elucidate that the inclusion of plant fibers led to a reduction in mechanical strength relative to pure PLA; however, when smaller particle sizes of plant fibers were added in volumes below 10%, it resulted in improved performance. Moreover, physical and/or chemical pretreatment of fibers, along with the isolation of cellulose fibrils, emerged as pivotal strategies for bolstering mechanical strengths. Noteworthy are the promising prospects presented by the incorporation of additives, while the refinement of printing parameters is key to improving the tensile and flexural strength of printed components.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139850079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hind M. Saleh, S. Albukhaty, G. Sulaiman, M. Abomughaid
The effective removal of organic dyes from aqueous solutions is of paramount importance in addressing environmental pollution challenges. Methylene blue (MB), a prevalent cationic dye in various industries, has raised concerns due to its persistence and potential adverse effects on ecosystems. This study explores the design, preparation, and characterization of Polycaprolactone–Chitosan (PCL–CH) nanofibers via electrospinning for the removal of MB. PCL, known for its biodegradability and mechanical properties, serves as the primary matrix, while chitosan (CH), with its biocompatibility and amino functionalities, offers enhanced adsorption potential. The electrospinning process yields nanofibers with tailored compositions and controlled morphology. The synthesized nanofibers are systematically characterized, encompassing structural analysis by Fourier transform infrared (FT–IR), spectroscopy, morphology, and composition assessment via Field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS), zeta potential, as well as rheological behavior evaluation. The adsorption uptake of MB onto these nanofibers is investigated, considering the influence of solution pH and initial dye concentration. The results reveal significant enhancements in adsorption capacity, especially with the incorporation of CH, with the PCL–CH 30% nanofibers exhibiting outstanding performance. The pH-dependent behavior underscores the importance of environmental factors in the adsorption process, while higher dye concentrations provide a stronger driving force for adsorption. These findings position PCL–CH nanofibers as promising adsorbents for the efficient removal of MB and potentially other organic contaminants from aqueous solutions. The study contributes to the development of sustainable materials for environmental remediation, wastewater treatment, and related applications, aligning with ongoing efforts to address water pollution challenges.
{"title":"Design, Preparation, and Characterization of Polycaprolactone–Chitosan Nanofibers via Electrospinning Techniques for Efficient Methylene Blue Removal from Aqueous Solutions","authors":"Hind M. Saleh, S. Albukhaty, G. Sulaiman, M. Abomughaid","doi":"10.3390/jcs8020068","DOIUrl":"https://doi.org/10.3390/jcs8020068","url":null,"abstract":"The effective removal of organic dyes from aqueous solutions is of paramount importance in addressing environmental pollution challenges. Methylene blue (MB), a prevalent cationic dye in various industries, has raised concerns due to its persistence and potential adverse effects on ecosystems. This study explores the design, preparation, and characterization of Polycaprolactone–Chitosan (PCL–CH) nanofibers via electrospinning for the removal of MB. PCL, known for its biodegradability and mechanical properties, serves as the primary matrix, while chitosan (CH), with its biocompatibility and amino functionalities, offers enhanced adsorption potential. The electrospinning process yields nanofibers with tailored compositions and controlled morphology. The synthesized nanofibers are systematically characterized, encompassing structural analysis by Fourier transform infrared (FT–IR), spectroscopy, morphology, and composition assessment via Field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS), zeta potential, as well as rheological behavior evaluation. The adsorption uptake of MB onto these nanofibers is investigated, considering the influence of solution pH and initial dye concentration. The results reveal significant enhancements in adsorption capacity, especially with the incorporation of CH, with the PCL–CH 30% nanofibers exhibiting outstanding performance. The pH-dependent behavior underscores the importance of environmental factors in the adsorption process, while higher dye concentrations provide a stronger driving force for adsorption. These findings position PCL–CH nanofibers as promising adsorbents for the efficient removal of MB and potentially other organic contaminants from aqueous solutions. The study contributes to the development of sustainable materials for environmental remediation, wastewater treatment, and related applications, aligning with ongoing efforts to address water pollution challenges.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"42 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139850010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Victor Hugo M. Almeida, Raildo M. Jesus, G. M. Santana, Thaís B. Pereira
The escalating global demand for polymer products and the consequent disposal challenge necessitate technological and sustainable solutions. Recent advances in the development of materials used in 3D printing equipment are described in this review, with a focus on new biocomposite materials. The investigation delves into biocomposites comprising PLA and its blends with other polymers, reinforced by plant fibers, with a particular focus on research conducted over the last five years. The information related to the raw materials’ physical, chemical, and processing properties necessary for creating biocomposite filament and printed parts were summarized. The best results in terms of tensile and flexural strength were presented and discussed, signposting future research avenues and desirable objectives. The findings elucidate that the inclusion of plant fibers led to a reduction in mechanical strength relative to pure PLA; however, when smaller particle sizes of plant fibers were added in volumes below 10%, it resulted in improved performance. Moreover, physical and/or chemical pretreatment of fibers, along with the isolation of cellulose fibrils, emerged as pivotal strategies for bolstering mechanical strengths. Noteworthy are the promising prospects presented by the incorporation of additives, while the refinement of printing parameters is key to improving the tensile and flexural strength of printed components.
{"title":"Polylactic Acid Polymer Matrix (Pla) Biocomposites with Plant Fibers for Manufacturing 3D Printing Filaments: A Review","authors":"Victor Hugo M. Almeida, Raildo M. Jesus, G. M. Santana, Thaís B. Pereira","doi":"10.3390/jcs8020067","DOIUrl":"https://doi.org/10.3390/jcs8020067","url":null,"abstract":"The escalating global demand for polymer products and the consequent disposal challenge necessitate technological and sustainable solutions. Recent advances in the development of materials used in 3D printing equipment are described in this review, with a focus on new biocomposite materials. The investigation delves into biocomposites comprising PLA and its blends with other polymers, reinforced by plant fibers, with a particular focus on research conducted over the last five years. The information related to the raw materials’ physical, chemical, and processing properties necessary for creating biocomposite filament and printed parts were summarized. The best results in terms of tensile and flexural strength were presented and discussed, signposting future research avenues and desirable objectives. The findings elucidate that the inclusion of plant fibers led to a reduction in mechanical strength relative to pure PLA; however, when smaller particle sizes of plant fibers were added in volumes below 10%, it resulted in improved performance. Moreover, physical and/or chemical pretreatment of fibers, along with the isolation of cellulose fibrils, emerged as pivotal strategies for bolstering mechanical strengths. Noteworthy are the promising prospects presented by the incorporation of additives, while the refinement of printing parameters is key to improving the tensile and flexural strength of printed components.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139790022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Ali Golshokouh, Nima Refahati, P. R. Saffari
The effect of silicon nanoparticles with different percentages (2, 5, 7, and 10 wt.%) on moisture absorption in environments with different pHs (5, 6, 7, 8, 9) as well as fracture toughness of polymethyl methacrylate is discussed. The samples were prepared using pressure molding. Fracture strength was tested via the three-point bending method according to the ASTM D5045 standard and moisture absorption rate according to the absorption test according to the ASTM D570 standard. SEM images show that up to 7%, the dispersion of silica nanoparticles is acceptable, but the homogeneity is not acceptable at 10%. The results indicate that the increase in silica nanoparticles has improved the fracture toughness of the manufactured parts. The highest fracture toughness improvement is about 57% in the optimal state at 5%. Also, increasing silica nanoparticles increased the moisture absorption in the produced samples. In addition, as the acidic or base of the liquid moves to neutral, the reaction between the base polymer molecules and the test liquid decreases and, so, the moisture absorption also increases.
{"title":"Effect of Silicon Nanoparticles on Moisture Absorption and Fracture Toughness of Polymethyl Methacrylate Matrix Nanocomposites","authors":"Mohammad Ali Golshokouh, Nima Refahati, P. R. Saffari","doi":"10.3390/jcs8020069","DOIUrl":"https://doi.org/10.3390/jcs8020069","url":null,"abstract":"The effect of silicon nanoparticles with different percentages (2, 5, 7, and 10 wt.%) on moisture absorption in environments with different pHs (5, 6, 7, 8, 9) as well as fracture toughness of polymethyl methacrylate is discussed. The samples were prepared using pressure molding. Fracture strength was tested via the three-point bending method according to the ASTM D5045 standard and moisture absorption rate according to the absorption test according to the ASTM D570 standard. SEM images show that up to 7%, the dispersion of silica nanoparticles is acceptable, but the homogeneity is not acceptable at 10%. The results indicate that the increase in silica nanoparticles has improved the fracture toughness of the manufactured parts. The highest fracture toughness improvement is about 57% in the optimal state at 5%. Also, increasing silica nanoparticles increased the moisture absorption in the produced samples. In addition, as the acidic or base of the liquid moves to neutral, the reaction between the base polymer molecules and the test liquid decreases and, so, the moisture absorption also increases.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"363 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139848167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hind M. Saleh, S. Albukhaty, G. Sulaiman, M. Abomughaid
The effective removal of organic dyes from aqueous solutions is of paramount importance in addressing environmental pollution challenges. Methylene blue (MB), a prevalent cationic dye in various industries, has raised concerns due to its persistence and potential adverse effects on ecosystems. This study explores the design, preparation, and characterization of Polycaprolactone–Chitosan (PCL–CH) nanofibers via electrospinning for the removal of MB. PCL, known for its biodegradability and mechanical properties, serves as the primary matrix, while chitosan (CH), with its biocompatibility and amino functionalities, offers enhanced adsorption potential. The electrospinning process yields nanofibers with tailored compositions and controlled morphology. The synthesized nanofibers are systematically characterized, encompassing structural analysis by Fourier transform infrared (FT–IR), spectroscopy, morphology, and composition assessment via Field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS), zeta potential, as well as rheological behavior evaluation. The adsorption uptake of MB onto these nanofibers is investigated, considering the influence of solution pH and initial dye concentration. The results reveal significant enhancements in adsorption capacity, especially with the incorporation of CH, with the PCL–CH 30% nanofibers exhibiting outstanding performance. The pH-dependent behavior underscores the importance of environmental factors in the adsorption process, while higher dye concentrations provide a stronger driving force for adsorption. These findings position PCL–CH nanofibers as promising adsorbents for the efficient removal of MB and potentially other organic contaminants from aqueous solutions. The study contributes to the development of sustainable materials for environmental remediation, wastewater treatment, and related applications, aligning with ongoing efforts to address water pollution challenges.
{"title":"Design, Preparation, and Characterization of Polycaprolactone–Chitosan Nanofibers via Electrospinning Techniques for Efficient Methylene Blue Removal from Aqueous Solutions","authors":"Hind M. Saleh, S. Albukhaty, G. Sulaiman, M. Abomughaid","doi":"10.3390/jcs8020068","DOIUrl":"https://doi.org/10.3390/jcs8020068","url":null,"abstract":"The effective removal of organic dyes from aqueous solutions is of paramount importance in addressing environmental pollution challenges. Methylene blue (MB), a prevalent cationic dye in various industries, has raised concerns due to its persistence and potential adverse effects on ecosystems. This study explores the design, preparation, and characterization of Polycaprolactone–Chitosan (PCL–CH) nanofibers via electrospinning for the removal of MB. PCL, known for its biodegradability and mechanical properties, serves as the primary matrix, while chitosan (CH), with its biocompatibility and amino functionalities, offers enhanced adsorption potential. The electrospinning process yields nanofibers with tailored compositions and controlled morphology. The synthesized nanofibers are systematically characterized, encompassing structural analysis by Fourier transform infrared (FT–IR), spectroscopy, morphology, and composition assessment via Field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDS), zeta potential, as well as rheological behavior evaluation. The adsorption uptake of MB onto these nanofibers is investigated, considering the influence of solution pH and initial dye concentration. The results reveal significant enhancements in adsorption capacity, especially with the incorporation of CH, with the PCL–CH 30% nanofibers exhibiting outstanding performance. The pH-dependent behavior underscores the importance of environmental factors in the adsorption process, while higher dye concentrations provide a stronger driving force for adsorption. These findings position PCL–CH nanofibers as promising adsorbents for the efficient removal of MB and potentially other organic contaminants from aqueous solutions. The study contributes to the development of sustainable materials for environmental remediation, wastewater treatment, and related applications, aligning with ongoing efforts to address water pollution challenges.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139790290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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