JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2022
·Vol. 106
·期 2
·1287-1298
·
IF 4.186
Xiaofeng Zhao,Yuancheng Teng,Yuxiang Li,Xiayu Zheng,Qiuyu Zheng,Rui Ma,Guangyuan Liu,Yang Liu,Rajeev Ahuja,Wei Luo
Rhabdophane has been considered an important permeable reactive barrier to isolate groundwater radionuclides, and evaluating its precipitation response to different species of radionuclide in acid solutions is critical. In this work, the effects of pH values on the precipitation behavior of Nd 3+ and Sm 3+ into La-rhabdophane are systematically investigated. Some specific issues such as ions removal, precipitation reaction kinetics, and crystal growth affected ions incorporation are discussed in detail, along with uncovering the veil of the Ln (La, Nd, and Sm) leaching mechanism of associated La 0.666 Nd 0.167 Sm 0.167 PO 4 monazite ceramic based on dissolution experiments and density functional theory. The results reveal that Nd 3+ and Sm 3+ can be removed more than 98% in pH = 1 solution within 12 h, whereas uneven precipitation process to form unexpected stoichiometric ratio of rhabdophane has been observed in 30–50 nm short crystal. Grain growth effects based on spark plasma sintering can contribute to homogenize the materials composition with obtaining La 0.666 Nd 0.167 Sm 0.167 PO 4 monazite ceramics. Furthermore, the binding energy of Ln–O in (1 0 0) surface of monazite plays an important role in controlling the leaching stability of Ln 3+ , associated with the leaching activities are energetically favorable in the order of La > Nd > Sm for La 0.666 Nd 0.167 Sm 0.167 PO 4 monazite.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 11
·3864-3871
·
IF 4.099
Aolei Gao,Zhenhua Sun,Shaopeng Li,Xinjuan Hou,Huiquan Li,Qisheng Wu,Xinguo Xi
Li1.6Mn1.6O4 is a representative ion sieve material that is used to recover lithium from salt brines and bitterns owing to its high lithium ion adsorption capacity reaching 11.9–44 mg g−1. However, manganese dissolution during acid treatment hinders the industrial application of the material. For investigating the mechanism of manganese dissolution, the precursor Li1.6Mn1.6O4 and ion sieve H1.6Mn1.6O4 were prepared and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), chemical content analyses, diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS), and X-ray photoelectron spectroscopy (XPS). The results of XRD, SEM, and FT-IR showed that the bulk phase of Li1.6Mn1.6O4 retained the spinel structure, whereas the lattice diminished during acid treatment. The results of chemical content analyses showed that the bulk phase of Li1.6Mn1.6O4 contained a few trivalent manganese atoms and that the mean valence of manganese in the material increased during acid treatment. DRIFTS and XPS exhibited that the surface of Li1.6Mn1.6O4 was mostly full of tetravalent manganese and retained the spinel structure during acid treatment. In the proposed mechanism of manganese dissolution, an electron of trivalent manganese in the bulk phase transfers to the surface and is captured by tetravalent manganese within the acidic environment. Then, tetravalent manganese is converted to bivalent manganese after acquiring sufficient electrons, and dissolution occurs simultaneously.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2017
·Vol. 19
·期 17
·10835-10842
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IF 4.123
Wenbin Jin,Yuqi Ke,Xianxian Liu,Qiwei Yang,Zongbi Bao,Baogen Su,Qilong Ren,Yiwen Yang,Huabin Xing
The development of new solvents combining greatly enhanced solubility for sparingly soluble compounds and good kinetic properties is challenging. In this study, we constructed a family of new molecular solvent/ionic liquid (IL) mixtures with amphiphilic, anionic functional long-chain carboxylate ionic liquids (LCC-ILs) as a key component for the solubilization of sparingly soluble compounds, using cholesterol as a model solute. Polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD), Fourier-transform infrared (FTIR) spectra and 1H NMR showed that ordered mesoscopic structures, such as liquid crystals (LCs), were formed when cholesterol was dissolved in the mixtures, presenting a self-assembly induced dissolution mechanism driven by H-bond interaction and van der Waals forces in the mixtures. A synergistic effect between the molecular solvents and LCC-ILs was revealed, which contributed to enhanced solute–solvent self-assembly in dissolution over pure LCC-ILs and thus elevated solubility. Additionally, the effect of IL concentration, solvent type and anionic alkyl-chain length on self-assembly and solubility was investigated. These mixtures showed unparalleled solubilities for cholesterol, while maintaining a low viscosity. The quantitative solubilities (g g−1) of cholesterol were as high as 0.70, 0.84 and 0.82, respectively, at 25 °C in ethyl acetate/[P4444][C15H31COO] (50 wt%), n-heptane/[P4444][C15H31COO] (40 wt%) and ethyl acetate/[P4444][C17H35COO] (50 wt%) mixtures, which were the highest solubilities of cholesterol ever reported, six- to 980-fold higher than traditional molecular solvents and even one- to seven-fold higher compared to pure LCC-ILs. These results demonstrated the considerable potential of molecular solvent/LCC-ILs mixtures as promising solvents for solubilization and advanced separation processes.
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 11
·3395
·
IF 4.927
Changli Ma,Taisen Zuo,Zehua Han,Yuqing Li,Sabrina Gärtner,Huaican Chen,Wen Yin,Charles C. Han,He Cheng
The atomic picture of cellulose dissolution in alkali/urea aqueous solution is still not clear. To reveal it, we use trehalose as the model molecule and total scattering as the main tool. Three kinds of alkali solution, i.e., LiOH, NaOH and KOH are compared. The most probable all-atom structures of the solution are thus obtained. The hydration shell of trehalose has a layered structure. The smaller alkali ions can penetrate into the glucose rings around oxygen atoms to form the first hydration layer. The larger urea molecules interact with hydroxide groups to form complexations. Then, the electronegative complexation can form the second hydration layer around alkali ions via electrostatic interaction. Therefore, the solubility of alkali aqueous solution for cellulose decreases with the alkali cation radius, i.e., LiOH > NaOH > KOH. Our findings are helpful for designing better green solvents for cellulose.Keywords:neutron total scattering;cellulose;dissolution mechanism;layered structure;complexation
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Peng Feng,Donghai Xu,Youwei Zhi,Bing He,Shuzhong Wang,Yaling He,Yang Guo
This work aims to explore the ability of molten salt to solve salt deposition in supercritical water (SCW) related technologies including supercritical water oxidation and supercritical water gasification, with KNO 3 and Na 2 SO 4 as examples. In the pure KNO 3 solution, the two-phase layering of high-density KNO 3 molten salt (settling at the reactor bottom) and low-density saturated KNO 3 -SCW salt solution (flowing out at the top outlet of the reactor) was formed in a kettle-reactor with about 6.5 ratio of depth to inner diameter, thereby improving the accuracy of measured solubilities. The precipitation macro-characteristics of mixed KNO 3 and Na 2 SO 4 in SCW were investigated under different feed concentration conditions. The results showed that Na 2 SO 4 deposition on the reactor sidewall could be reduced by more than 90 % when the mass ratio of KNO 3 to Na 2 SO 4 in the feed was only 0.167. No visible salt deposition was observed on the sidewall when the ratio was 0.374. All solid deposited salts were converted into the liquid molten salt as the ratio reached 3.341, and thus could easily flow out of the reactor, without plugging. ‘Molten salt dissolution’ mechanism may provide a more plausible explanation for mixed KNO 3 and Na 2 SO 4 in SCW. In addition, the precipitation micro-mechanisms of mixed KNO 3 and Na 2 SO 4 , and the critical conditions of avoiding sidewall deposition and reactor plugging were proposed. This work is valuable for overcoming the salt deposition problem in SCW-related technologies.
研究领域:
化学工程
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环境科学
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超临界流体技术
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产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
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2013
·Vol. 16
·期 3
·1326-1335
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IF 6.828
Benlian Lu,Airong Xu,Jianji Wang
As a kind of promising solvents, ionic liquids (ILs) have been used to dissolve cellulose and great progress has been made in recent years. However, the dissolution mechanism, especially the role of cations of ILs in the dissolution of cellulose, is still in debate. In this work, 13 kinds of ILs with a fixed anion [CH3COO]− but varied cationic backbones and alkyl chains have been prepared and characterized. The solubilities of cellulose in these ILs were measured at different temperatures. This allowed us to systematically study the effect of cationic structures on the cellulose dissolution at a given temperature. In order to investigate the dissolution mechanism, Kamlet–Taft parameters of these ILs in the temperature range from 25 to 65 °C and 13C NMR spectra of 1-benzyl-3-methylimidazolium acetate ([phC1mim][CH3COO]) + cellulose systems at 90 °C were also determined. It was found that acidic protons on the heterocyclic rings of the cations are essential for the dissolution of cellulose in the ILs, but the van der Waals interaction of cation with cellulose is not important. These protons may form C–H⋯O hydrogen bonds with hydroxyl and ether oxygen of cellulose to increase cellulose solubility. Cations of the ILs may also decrease cellulose solubility by strong interaction with anions or steric hindrance effect of large size group in their alkyl chains. These interactions together with strong O–H⋯O hydrogen bonds between the anion and hydroxyl protons of cellulose resulted in the disruption of the inter- and intra-molecular hydrogen bonds and thus effective dissolution of cellulose.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Chengqi Feng,Jiatian Zhu,Yajun Hou,Chengrong Qin,Wangqian Chen,Yuhao Nong,Zhangpeng Liao,Chen Liang,Huiyang Bian,Shuangquan Yao
Hemicelluloses were effectively separated using p -toluenesulfonic acid ( p -TsOH) treatment at high temperature. High temperature and pressure promoted hydrolysis of hemicellulose, which limited its value upon recovery. In this study, bagasse hemicellulose was separated and extracted by p -TsOH treatment at atmospheric pressure. The effects of temperature, p -TsOH concentration, and time on hemicellulose separation and extraction were investigated. The optimal conditions were 80 °C, 3.0% p -TsOH, and 120 min. The separation and extraction yield of hemicellulose was 73.23% and 36.02%, respectively. Extraction hemicellulose with 95.60% purity was obtained. In addition, the dissolution mechanism of hemicellulose was analyzed. Degradation of β-glycosidic bonds was inhibited. Benzyl ether bond between carbohydrates and lignin was selectively cleaved. The skeleton structure of xylan in hemicellulose was protected while the functional groups of branch chain were severely damaged. It provides a valuable theoretical basis for the efficient separation and extraction of hemicellulose.
研究领域:
生物化学
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可再生资源工程
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Danyang Cao,Qingwei Gao,Huaze Sun,Xin Feng,Jiahua Zhu,Xiaohua Lu,Liwen Mu
As a by-product of the pulp and paper industry, lignin is often used as fuel and even waste treatment. Lignin has the advantages of large reserves, degradability, natural oxidation resistance, etc., and has the required quality of green biodegradable functional additives. However, the high-value application of lignin often involves the dissolution recombination process, and the dissolution barrier of lignin limits its application. The research mechanism of the microscopic interaction mechanism of lignin efficient dissolution has not been revealed. To address this, we employed molecular dynamics (MD) simulations, density functional theory (DFT), nuclear magnetic resonance (NMR), and infrared spectroscopy to investigate the hydrogen bonding interactions between the β-O-4 bond model compound (lignin dimer) and novel solvent systems. These studies provide a deeper understanding of the interactions between solvent molecules and lignin model compounds, thereby offering theoretical support for the development and design of more effective lignin solvent systems.
研究领域:
生物化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
Hanwen Ge,Jiahui Wei,Shenglin Wang,Zexu Yan,Jiang Mingzhe,Lingxiao Zhu,Chao Liu,Bin Li,Caoxing Huang,Huanfei Xu
Heightened requirements in terms of environment, economy, and efficiency had been imposed on solvents used in the treatment of lignocellulose by the upgrading of the concept of green chemistry. Limitations were imposed on studies that only focus on enhancing a single interaction within the system due to the lack of understanding of the molecular-level mechanism in the solvent-biomass system. In this work, four novel ternary deep eutectic solvents (DES) were synthesized by adopting a new strategy in which the synergistic effect of hydrogen bonds (H-bonds), van der Waals (vdW) interactions and π-π stacking was used to enhance the delignification ability of DES. It was indicated by the results of quantum chemical calculation based on density functional theory (DFT) and molecular dynamics (MD) simulation that 84.26% and 68.72% of the electrostatic energy and vdW interaction energy in the DES-Lignin system were contributed, on average, by choline chloride (ChCl) and p-hydroxybenzoic acid (PB), with increases of 21.60% and 27.71% successively. This improvement was attributed to the increased molecular polarity resulting from the N⁺ on ChCl, the enhanced dispersion attraction due to the arrangement of methyl groups around the sp³-hybridized N⁺, and the π-π stacking interaction formed between the benzene ring structure of PB and lignin, which resulted in the enhancement of vdW interaction within the system. Affected by the ortho-substituents on the benzene ring, among the six investigated lignin dimers, stronger interactions with DES were exhibited by β-1 and β-O-4. The delignification ability of ChCl-LA-PB (strongest calculated interaction energy, reaching -92.37 kcal/mol) was demonstrated in the experiment of treating xylose residue. The delignification rate of lignin was increased by 1.86 times (up to 61.91%) compared with that of ChCl-LA. It was confirmed by the characterization resulted that the excessive depolymerization and condensation of lignin were avoided by the p-π conjugation effect of the phenolic hydroxyl group on PB through inhibiting the ionization of H⁺. Designing DES from the origin of molecular structure and adopting a strategy of multiple interactions in synergy provided novel insights and green methods for the high-value utilization of lignocellulose.
研究领域:
生物质化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2018
·
IF 5.018
Chunyan Wu,Lijian Zhang,Honghe Ding,Huanxin Ju,Xin Jin,Xiaomin Wang,Changfei Zhu,Tao Chen
Sb 2 S 3-x Se x (0 ≤x ≤ 3) is promising for practically applicable solar cell since it possesses excellent stability, suitable band gap, high extinction coefficient and abundant elemental storage. This study demonstrates a novel methodology towards simultaneous dissolution of Se and Sb 2 O 3 for direct deposition of Sb 2 S 3-x Se x films. Mechanistic study shows that the formation of selenium-nitrogen free radical in sulfur-containing complex is responsible for the dissolution of selenium. The energy levels of the as-synthesized Sb 2 S 3-x Se x were examined by synchrotron radiation photoemission spectroscopy , revealing that more Se in the Sb 2 S 3-x Se x leads to the valence band shifting considerably upward while the conduction band remaining nearly unchanged. Moreover, for the first time we present that the solution processed Sb 2 S 3-x Se x can generate photovoltaic performance with an efficiency of 5.8%. This research provides a straightforward strategy for the fabrication of Sb 2 S 3-x Se x solar cells and offers an effective method for the synthesis of metal selenosulfide films.
研究领域:
材料科学
·
太阳能电池技术
·
化学合成
✓ 已验证
产品关联
DOI
高影响因子
POLYMER INTERNATIONAL
·
2016
·Vol. 65
·期 4
·446-452
·
IF 2.414
Shuyan Yang,Biao Liu,Zhimeng Liu,Yuanqi Jiao
A novel borate ester (BE)-grafted carboxylated acrylonitrile butadiene rubber (XNBR) was synthesized. From Fourier transform infrared, 1 H NMR and elemental analyses, the borate ester was successfully grafted to XNBR, resulting in a more flexible XNBR chain as revealed by differential scanning calorimetry. The binding energies of boron, oxygen, lithium and chlorine atoms of XNBR- g -BE–LiClO 4 are quite different from those of XNBR or LiClO 4 . Meanwhile, the wavenumbers of C O B O C, CO and C H vibrations of the benzene ring shift towards lower values and a new shoulder peak for CN at about 2260 cm −1 emerges. By integrating fitting peak areas of CN groups and ClO 4 − , the fractions of CN group and ClO 4 − bidentate bonding in XNBR- g -BE–LiClO 4 are much higher than in NBR–LiClO 4 . Based on these experiments, a possible dissociation mechanism is proposed in which the boron atom of XNBR- g -BE receives electron pairs from ClO 4 − , releasing partial positive charge of Li + to bind with CN group. © 2016 Society of Chemical Industry
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Zicheng Du,Baojie Liu,Xiaoying Liu,Lu Liu,Chen Liang,Shuangquan Yao,Chengrong Qin
Separating low condensed lignin from lignocellulosic biomass is of great importance for achieving its full component conversion. This study proposed a new efficient and environmentally friendly alcohol/acid pretreatment system using 1,4-butanediol (1,4-BDO) as a solvent, combined with p -toluene sulfonic acid ( p -TsOH) to efficiently separate low condensed lignin. The results showed that the system could remove 85.55 % of hemicellulose and 84.78 % of lignin in a short time, with a high retention rate of cellulose. Based on the phenomenon of 1,4-BDO molecule protecting lignin structure, the recovered low-condensed lignin structure contains the main aliphatic hydroxyl structure, and the remaining solid surface lignin condensation grains were fewer, and the fiber crystallinity was high, which was beneficial for the preparation of high-value products. In addition, the lignin dissolution kinetics revealed that the p -TsOH/1,4-BDO pretreatment had a lower reaction activation energy, clarifying the solvation effect of 1,4-BDO on efficient lignin dissolution. Finally, combining density functional theory (DFT) from the molecular level clarified that the hydrogen bonding and conjugated effect between 1,4-BDO and lignin structure could effectively reduce the self-condensation reaction of lignin molecules. This study achieved effective separation of lignocellulosic biomass, providing a theoretical basis for the application of 1,4-BDO in biomass component separation, and promoting the development of green and efficient component separation technologies.
研究领域:
生物质化学
·
可再生资源工程
✓ 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）