Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18511
Kieu Do Trung Kien, Hanh Ong Dieu, Khoi Nguyen Hoang Thien, Minh Huynh Ngoc
Silicon carbide (SiC) is a mineral with good technical properties and high economic value. However, the synthesis of SiC is expensive because it is synthesized at a high-temperature environment (above 1500oC). The synthesis of SiC from biomass can significantly reduce the synthesis temperature. One commonly used biomass material for synthesizing SiC is rice husk. However, the ability to synthesize SiC depends on the shape of the rice husk. The influence of the morphology of rice husk on the ability to synthesize SiC was studied in this study. Experimental results showed that the original rice husk would give better SiC formation capacity than the rice husk powder. The amount of SiC formed using the original rice husk when impregnated by sodium silicate solution and pyrolysis at 1200oC is 18.3% (wt%.). With rice husk powder, it is 15.12% (wt%.). The results of analysis of the mineral composition, functional groups, and morphologies by X-ray diffraction (XRD), Fourier Infrared Transform Method (FT-IR), and Scanning Electron Microscopy (SEM) found that the polymorphy of SiC is α-SiC and β-SiC. These minerals are the basis for SiC from rice husks, which can be applied as wear-resistant materials.
碳化硅（SiC）是一种具有良好技术特性和较高经济价值的矿物。然而，由于碳化硅的合成需要在高温环境下（1500 摄氏度以上）进行，因此合成成本较高。利用生物质合成碳化硅可以大大降低合成温度。稻壳是合成碳化硅的一种常用生物质材料。然而，合成 SiC 的能力取决于稻壳的形状。本研究探讨了稻壳形态对合成碳化硅能力的影响。实验结果表明，原始稻壳比稻壳粉具有更好的碳化硅形成能力。原始稻壳经硅酸钠溶液浸渍并在 1200 摄氏度高温分解后，形成的 SiC 量为 18.3%（重量百分比）。使用稻壳粉则为 15.12%（重量百分比）。通过 X 射线衍射 (XRD)、傅立叶红外变换法 (FT-IR) 和扫描电子显微镜 (SEM) 对矿物成分、官能团和形态进行分析的结果表明，SiC 的多形态为 α-SiC 和 β-SiC。这些矿物是稻壳中 SiC 的基础，可用作耐磨材料。
{"title":"Effect of rice husk morphology on the ability to synthesize silicon carbide by pyrolysis method","authors":"Kieu Do Trung Kien, Hanh Ong Dieu, Khoi Nguyen Hoang Thien, Minh Huynh Ngoc","doi":"10.15625/2525-2518/18511","DOIUrl":"https://doi.org/10.15625/2525-2518/18511","url":null,"abstract":"Silicon carbide (SiC) is a mineral with good technical properties and high economic value. However, the synthesis of SiC is expensive because it is synthesized at a high-temperature environment (above 1500oC). The synthesis of SiC from biomass can significantly reduce the synthesis temperature. One commonly used biomass material for synthesizing SiC is rice husk. However, the ability to synthesize SiC depends on the shape of the rice husk. The influence of the morphology of rice husk on the ability to synthesize SiC was studied in this study. Experimental results showed that the original rice husk would give better SiC formation capacity than the rice husk powder. The amount of SiC formed using the original rice husk when impregnated by sodium silicate solution and pyrolysis at 1200oC is 18.3% (wt%.). With rice husk powder, it is 15.12% (wt%.). The results of analysis of the mineral composition, functional groups, and morphologies by X-ray diffraction (XRD), Fourier Infrared Transform Method (FT-IR), and Scanning Electron Microscopy (SEM) found that the polymorphy of SiC is α-SiC and β-SiC. These minerals are the basis for SiC from rice husks, which can be applied as wear-resistant materials.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"1 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807291","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18507
Thi Minh Nguyet Nguyen, V. Vuong, Huu Huy Phuc Nguyen, Van Thang Le
Green synthesis approaches have attracted greatly of attention in recent years since they address the issues associated with sustainability than conventional synthesis methods. New research fields in green nanoscience are being developed as a result of the incorporation of green chemistry principles into nanoscience. In this paper, the successful microwave-assisted green synthesis of MoS2 nanoparticles in a single pot using polyol solvents such as ethylene glycol and glycerol is demonstrated. The coexistence of 1T and 2H phases in MoS2 nanomaterials was determined using advanced techniques such as XRD, Raman, XPS, and TEM images. The highest 1T proportion obtained was 84.5% when compared to the 2H phase. The reaction mechanism and the phase transition between 1T and 2H were described and illustrated. The role of polyol solvents in the practical synthesis of nano MoS2 under microwave heating is also evaluated and explained. Due to the ability of the metallic 1T phase to enhance electrical conductivity, it is believed that hybrid nanostructures exhibit superior electrochemical performance for energy storage and conversion applications.
{"title":"Green synthesis of nanostructured 1T/2H-MoS2 hybrid phase with polyol solvents and microwave heating","authors":"Thi Minh Nguyet Nguyen, V. Vuong, Huu Huy Phuc Nguyen, Van Thang Le","doi":"10.15625/2525-2518/18507","DOIUrl":"https://doi.org/10.15625/2525-2518/18507","url":null,"abstract":"Green synthesis approaches have attracted greatly of attention in recent years since they address the issues associated with sustainability than conventional synthesis methods. New research fields in green nanoscience are being developed as a result of the incorporation of green chemistry principles into nanoscience. In this paper, the successful microwave-assisted green synthesis of MoS2 nanoparticles in a single pot using polyol solvents such as ethylene glycol and glycerol is demonstrated. The coexistence of 1T and 2H phases in MoS2 nanomaterials was determined using advanced techniques such as XRD, Raman, XPS, and TEM images. The highest 1T proportion obtained was 84.5% when compared to the 2H phase. The reaction mechanism and the phase transition between 1T and 2H were described and illustrated. The role of polyol solvents in the practical synthesis of nano MoS2 under microwave heating is also evaluated and explained. Due to the ability of the metallic 1T phase to enhance electrical conductivity, it is believed that hybrid nanostructures exhibit superior electrochemical performance for energy storage and conversion applications.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808945","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18519
Tien-Dat Thai, N. Huynh, Tuyen Luu, Kien Kieu Do Trung, Nhi Nguyen Vu Uyen, Minh Do Quang
Treating dredged sediment is a complex processing and ongoing challenge. To utilize dredged sediment for the landfill or construction purposes, a material fabricated from a mixture of dredged sediment, Portland cement, and fly ash, was cured under room temperature and hydrothermal condition at 180 °C and 0.9 MPa pressure for 16 hours. The response surface methodology was used to evaluate the compressive strength of the material, with the range of factors investigated being the dredged sediments/solid ratio (0.3-0.9), cement/fly ash ratio (2-4), and water/solid ratio (0.45-0.55). The fitting models offered an accurate and reliable match to the actual data. The optimum mix proportions of two curing conditions were obtained using total desirability function, meet multi-objective criteria. This result finger out hydrothermal curing significantly enhances treatment capacity of dredged sediment, with a lower CO2 emission in the mixture compared to ambient curing. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to figure out the difference between the minerals formed in the material under two curing conditions, such as tobermorite.
处理疏浚沉积物是一项复杂的工作，也是一项持续的挑战。为了将疏浚沉积物用于垃圾填埋场或建筑用途，一种由疏浚沉积物、硅酸盐水泥和粉煤灰混合制成的材料在室温和水热条件下于 180 °C 和 0.9 MPa 压力下固化了 16 小时。采用响应面法评估了材料的抗压强度，研究的因素范围为疏浚沉积物/固体比（0.3-0.9）、水泥/粉煤灰比（2-4）和水/固体比（0.45-0.55）。拟合模型与实际数据匹配准确可靠。利用总可取函数，满足多目标标准，获得了两种固化条件的最佳混合比例。结果表明，与常温固化相比，水热固化能显著提高疏浚沉积物的处理能力，同时降低混合物中的二氧化碳排放量。扫描电子显微镜（SEM）、X 射线衍射（XRD）和傅立叶变换红外光谱（FTIR）被用来研究两种固化条件下材料中形成的矿物（如托贝莫来石）之间的差异。
{"title":"Study on solidified material from dredged sediment, fly ash, and blended Portland cement using the response surface method","authors":"Tien-Dat Thai, N. Huynh, Tuyen Luu, Kien Kieu Do Trung, Nhi Nguyen Vu Uyen, Minh Do Quang","doi":"10.15625/2525-2518/18519","DOIUrl":"https://doi.org/10.15625/2525-2518/18519","url":null,"abstract":"Treating dredged sediment is a complex processing and ongoing challenge. To utilize dredged sediment for the landfill or construction purposes, a material fabricated from a mixture of dredged sediment, Portland cement, and fly ash, was cured under room temperature and hydrothermal condition at 180 °C and 0.9 MPa pressure for 16 hours. The response surface methodology was used to evaluate the compressive strength of the material, with the range of factors investigated being the dredged sediments/solid ratio (0.3-0.9), cement/fly ash ratio (2-4), and water/solid ratio (0.45-0.55). The fitting models offered an accurate and reliable match to the actual data. The optimum mix proportions of two curing conditions were obtained using total desirability function, meet multi-objective criteria. This result finger out hydrothermal curing significantly enhances treatment capacity of dredged sediment, with a lower CO2 emission in the mixture compared to ambient curing. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to figure out the difference between the minerals formed in the material under two curing conditions, such as tobermorite.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"58 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808468","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18544
Nguyen Hoang Thien Khoi, Nguyen Ngoc Tri Huynh, Nguyen Vinh Phuoc, Nguyen Khanh Son
This review delves into the utilization of rock powder as a mineral-derived fertilizer to support soil remineralization in the context of sustainable agriculture. Soil remineralization has emerged as a key strategy for ensuring long-term soil fertility and reducing the dependency on synthetic fertilizers. This review critically assesses the methodological approaches applied in various studies, taking into account factors such as local rock mineralogy, soil conditions, crop types, and nutrient uptake by plants. The review covers a range of methods, including nutrient value analysis, assessment of nutrient release rates, crop cultivation experiments in both laboratory and field settings, and the resulting implications for soil remineralization. Additionally, we present findings from a preliminary study focusing on the nutrient content of basalt rock from Nghe-An Province, Vietnam. This experimental investigation is centered on the assessment of nutrient values in a specific porous basalt material, which has been processed into micro-nanometer particles using a high-energy ball mill, thereby enhancing nutrient release efficiency. The study employs a range of analytical techniques, including XRD, XRF, SEM/EDS, and ICP-MS, to quantify macro- and micro-nutrient compositions. While the basalt rock samples may exhibit limitations in providing macronutrients (such as K) compared to commercial azomite rock, they offer distinct advantages in furnishing secondary macronutrients (like Ca). This comprehensive analysis provides insights into the potential use of micronized basalt rock for soil remineralization.
{"title":"comprehensive review of rock dust for soil remineralization in sustainable agriculture and preliminary assessment of nutrient values in micronized porous basalt rock from Nghe-An province, Vietnam","authors":"Nguyen Hoang Thien Khoi, Nguyen Ngoc Tri Huynh, Nguyen Vinh Phuoc, Nguyen Khanh Son","doi":"10.15625/2525-2518/18544","DOIUrl":"https://doi.org/10.15625/2525-2518/18544","url":null,"abstract":"This review delves into the utilization of rock powder as a mineral-derived fertilizer to support soil remineralization in the context of sustainable agriculture. Soil remineralization has emerged as a key strategy for ensuring long-term soil fertility and reducing the dependency on synthetic fertilizers. This review critically assesses the methodological approaches applied in various studies, taking into account factors such as local rock mineralogy, soil conditions, crop types, and nutrient uptake by plants. The review covers a range of methods, including nutrient value analysis, assessment of nutrient release rates, crop cultivation experiments in both laboratory and field settings, and the resulting implications for soil remineralization. Additionally, we present findings from a preliminary study focusing on the nutrient content of basalt rock from Nghe-An Province, Vietnam. This experimental investigation is centered on the assessment of nutrient values in a specific porous basalt material, which has been processed into micro-nanometer particles using a high-energy ball mill, thereby enhancing nutrient release efficiency. The study employs a range of analytical techniques, including XRD, XRF, SEM/EDS, and ICP-MS, to quantify macro- and micro-nutrient compositions. While the basalt rock samples may exhibit limitations in providing macronutrients (such as K) compared to commercial azomite rock, they offer distinct advantages in furnishing secondary macronutrients (like Ca). This comprehensive analysis provides insights into the potential use of micronized basalt rock for soil remineralization.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"52 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807030","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18562
Huynh Cong Khanh, Ly Thai Phap, Do Thanh Toan
Aluminum alloy of thermal-resistant aluminum alloy wire for overhead line conductors usually contains zirconium, silicon, iron, and other components. Hence, Al-Zr-Si master alloy can be used to produce thermal-resistant aluminum alloy. In this study, the manufacturing procedure of Al-Zr-Si master alloy from zircon concentrate has been introduced. The zircon concentrate was thoroughly mixed with different amounts of KCl and Na2SiF6 or Na3AlF6, then sintered in the electric muffle furnace at 700oC for 2 hrs with automatic temperature control. The sinter was premixed with Na3AlF6 at the 1:1 ratio and dried at 140-160oC to remove the humidity. The powder mixture was added to the aluminum molten at 1200oC and then stirred well to ensure proper powder mixing in the melt. After the finish reaction and slag skimming, the melt was taken out of the furnace and poured into the mold. The master alloy was characterized by a Spectrometer, ICP-OES, and optical microscopy.
{"title":"Manufacturing of Al-Zr-Si master alloy from zircon concentrate","authors":"Huynh Cong Khanh, Ly Thai Phap, Do Thanh Toan","doi":"10.15625/2525-2518/18562","DOIUrl":"https://doi.org/10.15625/2525-2518/18562","url":null,"abstract":"Aluminum alloy of thermal-resistant aluminum alloy wire for overhead line conductors usually contains zirconium, silicon, iron, and other components. Hence, Al-Zr-Si master alloy can be used to produce thermal-resistant aluminum alloy. In this study, the manufacturing procedure of Al-Zr-Si master alloy from zircon concentrate has been introduced. The zircon concentrate was thoroughly mixed with different amounts of KCl and Na2SiF6 or Na3AlF6, then sintered in the electric muffle furnace at 700oC for 2 hrs with automatic temperature control. The sinter was premixed with Na3AlF6 at the 1:1 ratio and dried at 140-160oC to remove the humidity. The powder mixture was added to the aluminum molten at 1200oC and then stirred well to ensure proper powder mixing in the melt. After the finish reaction and slag skimming, the melt was taken out of the furnace and poured into the mold. The master alloy was characterized by a Spectrometer, ICP-OES, and optical microscopy.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"62 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807497","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18528
Vu Thanh Dong, Pham Tien Hung, Le Duc Anh, Ly Quoc Vuong, Dang Duy Khanh, Nguyen Thi Huong
In this study, Zinc oxide (ZnO) nanoparticles with a size of about 50 - 70 nm were green-synthesized using tea leaves and ZnO/Polypyrrole (ZnO/Ppy) nanocomposites were obtained by ultrasonic-assisted chemical polymerization method using pyrrole monomer and the nanoparticles. The characterization of the materials is conducted using several analytical techniques, including Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) and Ultraviolet visible spectrum (UV-Vis). The synthesized PPy material exhibits have a rod-shaped structure, diameter ranging from 100 to 200 nm. The ZnO/PPy nanocomposite system, consisting of PPy rods surrounded by ZnO particles. The gas sensing characteristics of the materials have also been investigated by measuring their sensitivity, response time, and stability to NO2 at low temperature and different humidity. Notably, the material exhibits considerable sensitivity to NO2 gas at low temperatures and the parameters related to response and recovery times are relatively rapid. Furthermore, a potential gas-sensing mechanism based on changes in the width of the depletion region is proposed.
{"title":"Zinc Oxide/Polypyrrole particle-decorated rod structure for NO2 detection at low temperature","authors":"Vu Thanh Dong, Pham Tien Hung, Le Duc Anh, Ly Quoc Vuong, Dang Duy Khanh, Nguyen Thi Huong","doi":"10.15625/2525-2518/18528","DOIUrl":"https://doi.org/10.15625/2525-2518/18528","url":null,"abstract":"In this study, Zinc oxide (ZnO) nanoparticles with a size of about 50 - 70 nm were green-synthesized using tea leaves and ZnO/Polypyrrole (ZnO/Ppy) nanocomposites were obtained by ultrasonic-assisted chemical polymerization method using pyrrole monomer and the nanoparticles. The characterization of the materials is conducted using several analytical techniques, including Field Emission Scanning Electron Microscopy (FESEM) and X-Ray Diffraction (XRD) and Ultraviolet visible spectrum (UV-Vis).\u0000The synthesized PPy material exhibits have a rod-shaped structure, diameter ranging from 100 to 200 nm. The ZnO/PPy nanocomposite system, consisting of PPy rods surrounded by ZnO particles. The gas sensing characteristics of the materials have also been investigated by measuring their sensitivity, response time, and stability to NO2 at low temperature and different humidity. Notably, the material exhibits considerable sensitivity to NO2 gas at low temperatures and the parameters related to response and recovery times are relatively rapid. Furthermore, a potential gas-sensing mechanism based on changes in the width of the depletion region is proposed.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"56 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808958","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18533
Le Thi Bang, Nguyen Van Ha, Bui Duc Long, Nguyen T. Hong Nhung
Hydroxyapatite (HAp) is an inorganic component exhibiting bioactivity similar to that of natural bone. However, it is not resorbed by osteoclasts during bone remodelling due to its lack of bio-resorption property. This can be enhanced by the substitution of other element presented in bone mineral. In this research work, hydroxyapatite (HAp) and strontium-substituted hydroxyapatite (Sr-HAp) were synthesized by a precipitation method. Calcium nitrate tetra hydrate [Ca(NO3)2•4H2O], disodium hydrogen phosphate (Na2HPO4), and Strontium nitrate [Sr(NO3)2] were used as Ca, PO4 and Sr sources, respectively. Molar ratio Ca/P=1.67 was used to synthesize HAp, where (Ca+Sr)/P=1.67 was used to synthesize strontium substituted-HAp (Sr-HAp). The reaction was carried out at room temperature. The results show that pure HAp and Sr-HAp were formed with nanometer-sized particles. Sr substitution in the HAp lattice results in an increase in both the lattice disorder and crystal aspect ratio. The results of in vitro bioactive testing using simulated bodily fluid also showed that both HAp and Sr-HAp have high bioactive, with the Sr-HAp sample having the greater bioactive. Therefore, HAp and Sr-HAp have great potential for biological applications.
{"title":"Synthesis of hydroxyapatite and strontium-substituted hydroxyapatite for bone replacement and osteoporosis treatment","authors":"Le Thi Bang, Nguyen Van Ha, Bui Duc Long, Nguyen T. Hong Nhung","doi":"10.15625/2525-2518/18533","DOIUrl":"https://doi.org/10.15625/2525-2518/18533","url":null,"abstract":"Hydroxyapatite (HAp) is an inorganic component exhibiting bioactivity similar to that of natural bone. However, it is not resorbed by osteoclasts during bone remodelling due to its lack of bio-resorption property. This can be enhanced by the substitution of other element presented in bone mineral. In this research work, hydroxyapatite (HAp) and strontium-substituted hydroxyapatite (Sr-HAp) were synthesized by a precipitation method. Calcium nitrate tetra hydrate [Ca(NO3)2•4H2O], disodium hydrogen phosphate (Na2HPO4), and Strontium nitrate [Sr(NO3)2] were used as Ca, PO4 and Sr sources, respectively. Molar ratio Ca/P=1.67 was used to synthesize HAp, where (Ca+Sr)/P=1.67 was used to synthesize strontium substituted-HAp (Sr-HAp). The reaction was carried out at room temperature. The results show that pure HAp and Sr-HAp were formed with nanometer-sized particles. Sr substitution in the HAp lattice results in an increase in both the lattice disorder and crystal aspect ratio. The results of in vitro bioactive testing using simulated bodily fluid also showed that both HAp and Sr-HAp have high bioactive, with the Sr-HAp sample having the greater bioactive. Therefore, HAp and Sr-HAp have great potential for biological applications.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"43 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809584","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18515
Hoang Thien Khoi Nguyen, Ngoc Tri Huynh Nguyen, N. Huynh, Khanh Son Nguyen
Enhancing the durability of concrete by safeguarding it against cracking and environmental deterioration is paramount. While silicate-based densifiers have been instrumental in shielding concrete surfaces from wear and environmental factors, the surging popularity of lithium silicate solutions faces a significant impediment due to the high cost of lithium, mainly attributed to its predominant use in manufacturing lithium batteries. To address this substantial challenge, an intriguing approach involves blending lithium silicate with colloidal silica, potentially offering a cost-effective and efficient solution for concrete surface treatment. This study delves into the feasibility of utilizing lithium-stabilized colloidal silica as a silicate densifier, focusing on their preparation, characterization, and efficacy in lab-scale applications. The results demonstrate that lithium-stabilized colloidal silica can heighten surface hardness while concurrently reducing porosity. However, it is worth noting that this approach presents particular challenges, particularly regarding preparation and water resistance, when compared to surfaces treated solely with lithium silicate. Addressing these hurdles holds promise for optimizing and enhancing lithium-stabilized colloidal silica and advancing the concrete surface treatment field in future research endeavours.
{"title":"Preparation and characterization of Lithium-stabilized Colloidal Silica as a silicate densifier for concrete surface treatment","authors":"Hoang Thien Khoi Nguyen, Ngoc Tri Huynh Nguyen, N. Huynh, Khanh Son Nguyen","doi":"10.15625/2525-2518/18515","DOIUrl":"https://doi.org/10.15625/2525-2518/18515","url":null,"abstract":"Enhancing the durability of concrete by safeguarding it against cracking and environmental deterioration is paramount. While silicate-based densifiers have been instrumental in shielding concrete surfaces from wear and environmental factors, the surging popularity of lithium silicate solutions faces a significant impediment due to the high cost of lithium, mainly attributed to its predominant use in manufacturing lithium batteries. To address this substantial challenge, an intriguing approach involves blending lithium silicate with colloidal silica, potentially offering a cost-effective and efficient solution for concrete surface treatment. This study delves into the feasibility of utilizing lithium-stabilized colloidal silica as a silicate densifier, focusing on their preparation, characterization, and efficacy in lab-scale applications. The results demonstrate that lithium-stabilized colloidal silica can heighten surface hardness while concurrently reducing porosity. However, it is worth noting that this approach presents particular challenges, particularly regarding preparation and water resistance, when compared to surfaces treated solely with lithium silicate. Addressing these hurdles holds promise for optimizing and enhancing lithium-stabilized colloidal silica and advancing the concrete surface treatment field in future research endeavours.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"33 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141810106","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}
Pub Date : 2024-07-24DOI: 10.15625/2525-2518/18526
Xuan Viet Cao, Viet Chat Luong, Khanh Tuong Huynh, Uy Lan Du Ngoc
In this study, a thermosetting benzoxazine was successfully prepared from environmentally friendly sources to be used as an adhesive. The phenolic component used for the synthesis of the benzoxazine monomer is cardanol derived from the cashew nutshell, while the amine fractions are terephthalamide, which is a product of the amination process of used polyethylene terephthalate plastic bottles (PET). The structure of the benzoxazine monomer was determined by FT-IR and 1H-NMR spectroscopy. The thermal and curing behavior of the materials was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). A lap-shear adhesion testing (ASTM D1002-10) was performed to measure the bond strength of the material to the CT3 steel surface. The adhesive properties with a shear strength of 7.29 MPa are excellent compared to other commercial adhesives. This result indicates the great potential of this benzoxazine for adhesive applications in practice.
{"title":"Synthesis of Polybenzoxazine as an environmentally friendly adhesive material from cardanol and post-consumer PET source","authors":"Xuan Viet Cao, Viet Chat Luong, Khanh Tuong Huynh, Uy Lan Du Ngoc","doi":"10.15625/2525-2518/18526","DOIUrl":"https://doi.org/10.15625/2525-2518/18526","url":null,"abstract":"In this study, a thermosetting benzoxazine was successfully prepared from environmentally friendly sources to be used as an adhesive. The phenolic component used for the synthesis of the benzoxazine monomer is cardanol derived from the cashew nutshell, while the amine fractions are terephthalamide, which is a product of the amination process of used polyethylene terephthalate plastic bottles (PET). The structure of the benzoxazine monomer was determined by FT-IR and 1H-NMR spectroscopy. The thermal and curing behavior of the materials was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). A lap-shear adhesion testing (ASTM D1002-10) was performed to measure the bond strength of the material to the CT3 steel surface. The adhesive properties with a shear strength of 7.29 MPa are excellent compared to other commercial adhesives. This result indicates the great potential of this benzoxazine for adhesive applications in practice.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808298","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}
Pub Date : 2024-05-23DOI: 10.15625/2525-2518/19395
Thi Lan Anh Vu, Thi Nhan Nguyen, Thi Ha Thu Dang, The Hai Pham, Quoc Dinh Nguyen, Thi Thuy Huong Ngo, Van-Tuan Tran
Vetiver grass (Chrysopogon zizanioides) with a strong root system has been widely used for environmental pollution treatment. Recently, this grass has been cultivated at Bien Hoa airbase to mitigate dioxin concentration in the contaminated soil. Bacterial endophytes have been recognized to play key roles in plant growth promotion and responses of plant hosts to environmental factors. However, a beneficial association between endophytic bacteria and Vetiver grass root system grown in dioxin-contaminated soil has not been elucidated. In the present study, we isolated sixteen endophytic bacterial strains from the roots of Vetiver grass. The results of DNA sequencing of the 16S rRNA gene revealed that these culturable bacterial endophytes belong to 9 species of different genera. Four strains, including Klebsiella variicola B1, Enterobacter cloacae B4, Enterobacter kobei B6, and Enterobacter cloacae B11, produce high amounts of indol acetic acid (IAA). Strains K. variicola B1 and E. cloacae B4 also produce phytase and phosphatase to dissolve phytate and phosphate, respectively. These strains were selected to evaluate their abilities in promoting the growth of tomato plants as a model. After 28 days of inoculation with the tested strains through the roots, tomato plants grew 19% to 22% faster than the control plants. Conclusively, this study shows for the first time the successful isolation of endophytic bacteria from the roots of Vetiver grass cultivated in dioxin-contaminated soil, and some culturable bacterial strains exhibit as promising candidates for plant growth promotion.
{"title":"A snapshot of bacterial endophytes isolated from the roots of Vetiver grass (Chrysopogon zizanioides) grown at Bien Hoa airbase, Dong Nai province","authors":"Thi Lan Anh Vu, Thi Nhan Nguyen, Thi Ha Thu Dang, The Hai Pham, Quoc Dinh Nguyen, Thi Thuy Huong Ngo, Van-Tuan Tran","doi":"10.15625/2525-2518/19395","DOIUrl":"https://doi.org/10.15625/2525-2518/19395","url":null,"abstract":"Vetiver grass (Chrysopogon zizanioides) with a strong root system has been widely used for environmental pollution treatment. Recently, this grass has been cultivated at Bien Hoa airbase to mitigate dioxin concentration in the contaminated soil. Bacterial endophytes have been recognized to play key roles in plant growth promotion and responses of plant hosts to environmental factors. However, a beneficial association between endophytic bacteria and Vetiver grass root system grown in dioxin-contaminated soil has not been elucidated. In the present study, we isolated sixteen endophytic bacterial strains from the roots of Vetiver grass. The results of DNA sequencing of the 16S rRNA gene revealed that these culturable bacterial endophytes belong to 9 species of different genera. Four strains, including Klebsiella variicola B1, Enterobacter cloacae B4, Enterobacter kobei B6, and Enterobacter cloacae B11, produce high amounts of indol acetic acid (IAA). Strains K. variicola B1 and E. cloacae B4 also produce phytase and phosphatase to dissolve phytate and phosphate, respectively. These strains were selected to evaluate their abilities in promoting the growth of tomato plants as a model. After 28 days of inoculation with the tested strains through the roots, tomato plants grew 19% to 22% faster than the control plants. Conclusively, this study shows for the first time the successful isolation of endophytic bacteria from the roots of Vetiver grass cultivated in dioxin-contaminated soil, and some culturable bacterial strains exhibit as promising candidates for plant growth promotion.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"19 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141107558","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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