JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2021
·Vol. 147
·期 15
·8177-8188
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IF 4.626
Fang Manting,Zhang Xuelai,Ji Jun,Hua Weisan,Zhao Yi,Liang Jiyuan
In order to solve the phase separation problem of Na 2 S 2 O 3 ·5H2O–CH3COONa·3H 2 O PCM (phase change material), sodium carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), xanthan gum (XG), sodium polyacrylate (PAAS) and polyacrylamide (PAM) were selected as additives. The effects of different proportions of the above thickeners on the supercooling degree, phase separation, phase change temperature and latent heat of Na 2 S 2 O 3 ·5H2O–CH3COONa·3H 2 O system were studied by using the cooling curve and DSC, so as to screen the best thickener for eutectic PCM. The experimental results show that CMC, XG and PAAS can eliminate the phase separation of Na 2 S 2 O 3 ·5H2O–CH3COONa·3H 2 O. Among them, the optimal ratio of CMC, XG and PAAS is 3 mass%, 3 mass% and 1 mass%, respectively. From the perspective of heat storage performance, PAAS is the optimal thickener for Na 2 S 2 O 3 ·5H2O–CH3COONa·3H 2 O. The phase change temperature is 40.5 °C. The subcooling degree is about 14.7 °C, and the latent heat is about 221 J g −1 . The melting time is 15 min. Only PAAS can make Na 2 S 2 O 3 ·5H2O–CH3COONa·3H 2 O eutectic PCM completely exothermic at room temperature, which can not only play the role of thickener to eliminate phase separation, but also is a nucleating agent. After 100 melting-solidification cycles, the change rate of latent heat value was only 5%, and the change rate of phase transition temperature was less than 1%. Considering heat storage performance and cyclic stability, PAAS is the optimal thickener for Na 2 S 2 O 3 ·5H2O–CH3COONa·3H 2 O PCM.
研究领域:
材料科学
·
热能存储
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY & BIODIVERSITY
·
2024
·
IF 2.3
Yongchang Bi,Jingjun Wang,Xingyu Bian,Mingyue Chen,Guangyuan Zhu,Yumin Zhang,Qiang Gu
An efficient and green method for synthesizing 3-methyl-4-(hetero) arylmethylene isoxazole-5(4 H )-ones was developed using a recyclable and environmental–friendly catalyst, Na 2 S 2 O 3 , and 16 target compounds were successfully synthesized under the obtained optimal reaction condition. Using rifampicin as a positive control, the antibacterial activity of all synthesized compounds was tested by micro dilution method, among them, 3-methyl-4-[(2,4-dimethoxyphenyl) methylene]-isoxazole-5-one ( 4 m ) presented wonderful antimicrobial activity, which may contribute to the development of anti-tuberculosis drugs. Graphical
研究领域:
有机化学
·
药物化学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yi Han,Mengxin Guo,Ting Shi,Zhipeng Wang,Yi Wang,Zhibing Xu,Dejin Wang,Hongcheng Gao,Zheng Peng,Haobo Hou
The dynamic changes in the iron redox cycle (Fe 2+ /Fe 3+ ) played a crucial role in the electro-Fenton degradation of organic pollutants. The synthesis of composite particle electrodes RMSSx:y from a mixture of steel slag (SS) and red mud (RM) was applied in a three-dimensional electrochemical system for the remediation of hydrochloric tetracycline (TCH) in wastewater, utilizing Na 2 S 2 O 3 as an electrolyte. Further, some investigations were conducted to determine the effects of RM/SS, electrolyte, particle electrode dosage, cell voltage, and pH on TCH degradation efficiency. Under optimal conditions such as 8 g/L RMSS 5:5 particle electrodes, a cell voltage of 4 V, an initial pH of 3, and 6 mM Na 2 S 2 O 3 electrolyte, the degradation rate of TCH in wastewater was 98.3 %. Meanwhile, its total organic carbon (TOC) was reduced by 88 % within 60 min. Cyclic experiments with consistently high degradation efficiency demonstrated the stability of the particle electrode RMSS 5:5 . The practical applicability of RMSS 5:5 was further confirmed through its successful treatment of various industrial wastewaters, including dyeing (DW), chemical (CW), and pharmaceutical (PW) effluents, achieving chemical oxygen demand (COD) removal rates of 67.8 %, 67.6 %, and 65.0 % respectively. The enhancement of TCH degradation through the utilization of Na 2 S 2 O 3 as the electrolyte was primarily attributed to the complexation and reduction effects exerted by S 2 O 3 2- ions. These effects prevented the leaching and precipitation of iron ions, facilitated the reduction of Fe (III), and consequently enabled •OH ads to play a dominant role in the degradation process. These findings demonstrated the potential of RMSS 5:5 in efficiently degrading emerging contaminants, thereby offering an innovative approach for utilizing SS and RM as functional materials in electro-Fenton processes.
研究领域:
环境科学
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电化学工程
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污染治理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2017
·
IF 4.849
Qiujie Tang,Zhaogang Bian,Wei Wu,Jin Wang,Ping Xie,Charles U. Pittman,Jr.,Aihua Zhou
The method for constructing C–S bonds is very important in organic synthesis. Here a new sulfenylation method to generate flavone thioether derivatives was developed by employing aromatic or alkyl halides, S powder and Na2S2O3 as reactants. Good yields of regioselective Calkyl–S and Caryl–S-substituted flavones were generated under relatively environmentally friendly and simple conditions. This method might be potentially applicable to large scale production, and it enriches current sulfenylation methods.
研究领域:
有机化学
·
药物合成
✓ 已验证
DOI
PubMed
高影响因子
JOM
·
2019
·Vol. 71
·期 10
·3673-3681
·
IF 2.305
Gao Guilan,He Xin,Lou Xiaoyi,Jiao Zheng,Guo Yaoguang,Chen Shuai,Luo Xingmin,Sun Suyang,Guan Jie,Yuan Hao
Recycling of valuable metals from spent lithium-ion batteries (LIBs) appears inevitable for both environmental protection and resource recovery. In the present study, an efficient hydrometallurgical leaching of Co and Li from cathode materials of spent LIBs using a citric acid/sodium thiosulfate (Na 2 S 2 O 3 ) system is explored. The effects of citric acid and Na 2 S 2 O 3 concentrations, leaching time, temperature, and the solid/liquid ( S / L ) ratio on the leaching processes are also examined. With the exception of the S / L ratio, the increase of citric acid concentration, Na 2 S 2 O 3 concentration, leaching time, and temperature all have positive effects on the leaching of Co and Li. Ultimately, approximately 96% of Co and 99% of Li are recycled from the spent LIBs in this citric acid/sodium thiosulfate system under the leaching conditions of an S / L ratio of 20 g l −1 , concentration of Na 2 S 2 O 3 of 0.3 M, concentration of citric acid of 1.2 M, leaching time of 30 min, and leaching temperature of 70°C. The Avrami equation is well fitted by the data of the leaching processes, and model equations are built to describe the leaching of Co and Li. Furthermore, pure sulfur can be obtained as a by-product during the leaching process, and SO 2 produced during the reaction is easily collected as a raw material for industrial production of sulfuric acid. The present study represents a promising process for hydrometallurgical recovery of valuable metals from spent LIBs.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Shuangjie Xiao,Zilan Jin,Haoran Dong,Junyang Xiao,Yangju Li,Long Li,Rui Li,Jie Chen,Ran Tian,Qianqian Xie
There are plentiful ways to synthesize sulfidized nanoscale zerovalent iron (S-nZVI), and this study investigated the influence of sulfur reagents (Na 2 S, Na 2 S 2 O 3 , Na 2 S 2 O 4 ) and sulfidation sequence (co-sulfidation and post-sulfidation method) on the physicochemical properties, reactivity, and long-term performance of S-nZVI in simulated groundwater. The results suggested that the co-sulfidized nZVI (S-nZVI co ) has higher reactivity (∼2-fold) than S-nZVI post due to the stronger electron transfer capacity, deriving from the higher content of Fe 0 and reductive sulfur species. However, during aging, the reactivity of S-nZVI co would be lost more rapidly than S-nZVI post , due to the faster corrosion of Fe 0 and more oxidation of reductive sulfur species. S-nZVI post has the superior long-term performance with the degradation rate of trichloroethylene (TCE) remained at 30%∼60% even after 90 d of aging. Sulfur precursors can control the selectivity of S-nZVI by affecting the sulfur speciation on the particle surface. The proportion of reductive sulfur species on S-nZVI post synthesized by Na 2 S was higher than S-nZVI post synthesized by Na 2 S 2 O 3 or Na 2 S 2 O 4 , resulting in a higher selectivity of the former S-nZVI post than the latter S-nZVI post . In addition, sulfidation procedures and sulfur precursors did not affect the degradation pathway of TCE. Nevertheless, the degradation product distribution can be affected by the different physicochemical transformation of various types of S-nZVI with the aging time. These results indicated that sulfur reagents and sulfidation procedures have crucial effects on the reactivity and long-term performance of S-nZVI, which can be designed for the specific application scenarios.
研究领域:
环境科学
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biochar
·
2023
·Vol. 5
·期 1
·1-18
·
IF 12.7
Wang Shulian,Huang Yan,Ma Shuanglong,Zhan Sihui,Wang Jingzhen,Gao Boqiang,Tang Xiaodan,Zhu Qiuhui,Xu Shengjun,Zhuang Xuliang
Metal-free porous biochars are popularly utilized as catalysts for peroxydisulfate (PDS) activation. The enhancement effect of PDS activation of porous biochars fabricated by employing both hard template and alkali metal activating agent has not been explored completely. In addition, the role of the inherent carbon defect in PDS activation has not been clearly elucidated. Hence, a series of carbonaceous catalysts were fabricated using a sole template (KCl), a sole activating agent (Na 2 S 2 O 3 ) or a combination of template and activating agent (KCl/Na 2 S 2 O 3 , KCl/KHCO 3 , KCl/NaHCO 3 , and KCl/Na 2 C 2 O 4 ), to systematically investigate the effect of specific surface area (SSA) and intrinsic defect of porous biochar on its PDS activation ability. The biochar synthesized by KCl and Na 2 S 2 O 3 (SK-C) exhibited the optimum degradation performance. The SK-C was found to possess an interconnected hollow cage with three-dimensional mesh structure showing the largest surface area, pore volume and C- sp 3 edge defect content among all the catalysts, which explained its paramount catalytic ability. The SSA and C- sp 3 content together can determine the catalytic performance in a quantitative relationship. The single electron transfer pathway from SDZ to inner-sphere bound SK-C/PDS* was the protagonist of pollutant oxidation. The degradation intermediates were detected and recognized and their toxicities were evaluated. This study for the first time comprehensively identified the synergistic effect between the SSA and inherent defects on improving the catalytic performance of biochar for PDS activation to removal contaminants. Graphical Abstract
研究领域:
环境科学
·
材料科学
·
化学工程
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）