PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 29
·19446-19452
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IF 3.3
Xiaobin Fu,Yiyang Liu,Hailong Huang,Huiyan Wu,Jianchao Sun,Ling Han,Min Ge,Yuan Qian,Hongtao Liu
The 2LiF-BeF2 (FLiBe) salt melt is considered the primary choice for a coolant and fuel carrier for the generation IV molten salt reactor (MSR). However, the basics of ionic coordination and short-range ordered structures have been rarely reported due to the toxicity and volatility of beryllium fluorides, as well as the lack of suitable high-temperature in situ probe methods. In this work, the local structure of FLiBe melts was investigated in detail using the newly designed HT-NMR method. It was found that the local structure was comprised of a series of tetrahedral coordinated ionic clusters (e.g., BeF42−, Be2F73−, Be3F104−, and polymeric intermediate-range units). Li+ ions were coordinated by BeF42− ions and the polymeric Be–F network through the analysis of the NMR chemical shifts. Using solid-state NMR, the structure of solid FLiBe solidified mixed salts was confirmed to form a 3D network structure, significantly similar to those of silicates. The above results provide new insights into the local structure of FLiBe salts, which verifies the strong covalent interactions of Be–F coordination and the specific structural transformation to the polymeric ions above 25% BeF2 concentration.
研究领域:
核能科学
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材料化学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 22
·6728-6743
·
IF 6.641
Xuyang Zhang,Ruili Zhang,Lili Hu,Jinjun Ren
A series of 16BaF2–(84 − x)NaPO3–xYF3–yErF3 (x = 0, 12, 24, 36, and 48 mol%; y = 0.1, 0.5, and 1 mol%) glasses were prepared via the conventional melt-quenching method and subsequently heated to synthesize glass ceramics containing Er3+-doped Na5Y9F32 crystals. The structures of glasses and glass ceramics were characterized by multiple advanced one- and two-dimensional solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. At the atomic level, multiple phosphorus species Qn (n = 0, 1, and 2) were resolved. Here, the value n denotes the number of P–O–P bonds, which can be quantified by 2D J-resolved spectroscopy. The connectivity between F− ions and cations was detected by the rotational echo double resonance (REDOR) and the J-coupling based heteronuclear multiple quantum coherence (HMQC) method. With the increase of YF3 content, the phosphate network depolymerized gradually. 31P and 19F MAS spectra, as well as 23Na {31P} and 23Na {19F} REDOR results, consistently proved that Y3+ ions, replacing partial Ba2+ and Na+ ions, aggregated around phosphorus tetrahedrons [PO4]3−, whereas partial Ba2+ and Na+ ions moved away from [PO4]3− to bond with F− ions and formed Y–F⋯Na and Ba–F⋯Na linkages. All cations could exist as oxygen and fluorine complex ligand units M(OxFy), besides single oxygen ligand units M(Ox+y), where M represents cations in glasses. When YF3 content reached 48% by mole, micro-regions enriched in Y–F⋯Na linkages were formed, which promoted the crystallization. 31P MAS spectra indicated that the crystallization of Na5Y9F32 crystals has not affected the local structure of phosphorus species. Intensive upconversion luminescence can be observed in the fluoro-phosphate glass ceramics containing Er3+:Na5Y9F32 crystals. On the basis of these complementary evidences from solid-state NMR experiments and luminescence spectra, a novel structure evolution model during crystallization is developed.
研究领域:
材料科学
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光物理学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2016
·Vol. 18
·期 29
·19731-19737
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IF 4.449
Yingna Cui,Jingmei Yin,Changping Li,Shenmin Li,Ailing Wang,Guang Yang,Yingping Jia
The compositions and structures of amine-based functionalized protic ionic liquids (PILs), namely N,N-dimethyl(cyanoethyl)ammonium propionate (DMCEAP) and N,N-dimethyl(hydroxyethyl)ammonium propionate (DMEOAP) have been investigated systematically by IR and 1H NMR spectroscopy and density functional theory (DFT) calculations. Analysis of the IR spectra suggests that both DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase, the former one mainly existing in the state of precursor molecules, and the latter mainly as ion-pairs. The ratio of precursor molecules to ion-pairs in the liquid phase depends on the types of precursors, especially the functional groups of cations. 1H NMR spectra indicate that there is a dynamic equilibrium between the neutral and ionized species, probably due to the formation of some intermediates in the PILs. The DFT calculations have been carried out to reveal the conformation, and obtain the corresponding IR and 1H NMR spectra of the neutral and ionized species, so that the theoretical support to the experimental results can be provided. The present study will help understand the properties of PILs and provide guidance for further applications of PILs.
研究领域:
物理化学
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离子液体化学
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光谱学
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理论化学
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分析化学
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材料化学
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2026
·
IF 6.1
Hui Ma,Jiankai Huang,Chao Luo,Weiguang Yang,Yan Chen,Feifeng Pang,Weibang Yu,Kefeng Wu,Yingxiong Wang,Qi Zhao
NMR spectroscopy is a powerful spectroscopic technique that permits the detailed study of the molecular structure elucidation and mixture component analysis, especially in the identification of complex mixtures. However, the conventional 1 H NMR generally suffers from crowded resonances when measuring and identifying carbohydrates of polysaccharide hydrolysis systems, which contain various chemically similar compounds and even multiple isomeric monosaccharides. Herein we describe the application of a targeted detection NMR approach, gradient-enhanced multiplet-selective targeted-observation NMR experiment GEMSTONE–TOCSY, exploited for studying polysaccharide hydrolysis mixtures by spectroscopically targeting the desired compounds in separate 1D NMR spectra. There are six model mixtures of natural bioactive polysaccharide hydrolysis (including 11 monosaccharides) and three real reaction systems (carob seed polysaccharide, tremella polysaccharide and stachyose hydrolysis), which are tested by GEMSTONE–TOCSY NMR showing satisfactory performance in monosaccharide identification and structure analysis even when proton signals are crowded and overlapped in conventional 1 H NMR. Moreover, GEMSTONE–TOCSY NMR uses a fast, single-scan method that allows selective excitation of the signals of a single proton multiplet and available for highly efficient analysis. The results demonstrate that GEMSTONE–TOCSY NMR technique is robust and reliable to analyze and identify monosaccharide composition of various polysaccharides from mixture systems, even providing efficient analysis tool for detecting the polysaccharide hydrolysis process.
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2025
·
IF 5.4
Runyin Li,Shuangbo Yin,Tong Zheng,Chenju Zhang,Jiawen Hou,Pingchuan Sun,Yun Gao,Xiaoliang Wang
Mediums and particles could form a typical shear thickening fluid (STF) whose viscosity increased significantly while shear rate was larger than the critical value. Such jump of viscosity could be controlled by particle-medium interactions. The quantitative relationship between particles and different mediums was still less studied. We used polyethylene glycol 200 and silica nanospheres as a typical STF. The bridging effect may cause a gel while bad medium, like water, made STF dysfunctional. The relaxation behavior and the dynamical heterogeneity of these samples were characterized by solid-state 1 H low-field NMR. One mediate apparent spin-spin relaxation time ( T 2 ) could be found by fitting fully refocused FID in the typical STF. A strong interaction with typical T 2 of 0.14 ms was extracted in particle gels with bridging effect. Interestingly, when two good mediums were mixed, STF became gel-like and their T 2 decreased more rapidly than single medium with increasing particle content. On the contrary, bad medium preferentially lubricated particle surface and broke original particle-medium interactions, which was evidenced by a higher T 2 value when small amount of bad medium was added. Such dynamic information obtained from NMR agreed well with the corresponding rheology behavior. A tentatively quantitative criterion of dynamics was proposed to judge whether shear thickening can occur in a particle suspension.
研究领域:
材料科学
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物理学
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DOI
高影响因子
Journal of Energy Chemistry
·
2025
·
IF 14.9
Vestince Balidi Mbayachi,Lixin Liang,Bao Zhang,Yaru Zhang,Guiming Zhong,Kuizhi Chen,Guangjin Hou
Composite polymer electrolytes (CPEs) are considered as promising electrolytes for next-generation lithium batteries due to their superior advantages in safety, mechanical stability/flexibility, cathode compatibility, etc. However, achieving high Li + conductivity remains a major challenge, particularly at low temperatures. A key obstacle lies in the limited understanding of the complex interplay among amorphous components, including fillers, plasticizers, and residual solvents, which significantly hampers the rational design of high-performing CPEs. In this contribution, a polyvinylidene fluoride (PVDF)-based composite electrolyte has been developed, exhibiting high room-temperature ionic conductivity/mobility (>1 mS cm −1 /0.95 × 10 −11 m 2 s −1 ), along with excellent electrochemical performances, including a wide stability window (4.8 V vs. Li/Li + ), superior charge/discharge capacity, and reversibility. By performing advanced solid-state nuclear magnetic resonance (ssNMR) techniques, in combination with systematic investigations into solid polymer electrolytes (SPEs), gel polymer electrolytes (GPEs), and CPEs, we establish an efficient NMR-based strategy for deconvoluting the structural and dynamic features of complex electrolyte systems. Notably, the simple 1 H magic-angle spinning (MAS) NMR spectroscopy enables the identification and monitoring of nearly all components in the composite matrix. Motion-Sensitive 1 H- 13 C and 1 H- 7 Li correlation experiments further reveal that the rigidity of PVDF polymer chain segments and the presence of residual solvents are two critical factors governing Li + mobility. Moreover, we demonstrate that the order of the filler and plasticizer addition during the CPE fabrication significantly influences the performance of the electrolyte by regulating the retention of residual solvents. This work not only provides molecular-level insights into the structure-ion mobility relationships in the PVDF-based CPEs but also establishes a general NMR-based characterization approach for investigating other complex composite electrolyte materials.
研究领域:
材料科学
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电化学
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固态化学
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高分子科学
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核磁共振波谱学
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产品关联
DOI
高影响因子
Metabolites
·
2025
·Vol. 15
·期 3
·152
·
IF 3.7
Yangzong Zhuoma,Minghong Yang,Yijie Chen,Xiangxi Zhang,Xingyan Duan,Hongwei Cui,Xin Fang,Xujia Hu
Background:Wild boletes are famous for their exceptional flavor and nutritional value. Due to their susceptibility to decay and spoilage, dry storage is a common method for processing and preservation. However, few studies have reported on the alterations of metabolites of boletes resulting from different drying methods. This paper aims to investigate the metabolic changes in two species of boletes,Butyriboletus roseoflavusandLanmaoa asiatica, subjected to three drying methods: hot-air drying, microwave drying, and freeze drying.Method and Result:Nuclear magnetic resonance (NMR) metabolomics was utilized for multivariate data analysis. In total, 27 metabolites were identified from the two species of boletes, including amino acids such as glutamate and leucine, sugars like glucose and sucrose, and alkaloids like choline. Among these, 17 metabolites were classified as differential metabolites, comprising 12 amino acids, 4 sugars, and 1 alkaloid. Differential metabolites were quantified by quantitative NMR (qNMR), and these metabolites were subsequently analyzed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database for pathway enrichment analysis. KEGG pathway analysis revealed that the different drying methods resulted in significantly distinct metabolic pathways for these differential metabolites, resulting in the enrichment of amino acid metabolism and starch and sucrose metabolism pathways.Conclusions:This metabolomics study elucidates the differences in metabolite composition and abundance between the two species of boletes, providing a theoretical foundation for selecting appropriate drying methods for their preservation.
研究领域:
食品科学
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代谢组学
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真菌学
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2025
·
IF 7.7
Xiaojing Chen,Quan Tao,Siwei Yang,Hang Wang,Xuelian Wang,Guqiao Ding,Xiumin Gao,Hui Dong,Liangliang Rong
Aging allows the occurrence and progression of cerebrovascular diseases, highlighting the importance of detecting senescent cells and tissues in the nervous system. Detecting senescent cells/tissues using nanoparticles as probes in the nervous system is desired with high sensitivity, high accuracy, and penetration of the blood-brain barrier. In response, we designed crown ether-based graphene quantum dots with fast proton transport channels to sense potassium ions, a significant differential indicator between healthy and senescent cells. Using the probe, we have achieved MRI-fluorescence dual-functional monitoring of potassium ion concentration in cells via fluorescent intensity and magnetic relaxation time. Importantly, we have further demonstrated the advantages of the crown ether-based graphene quantum dots in penetrating the blood-brain barrier, revealing their potential for diagnosing aging in the nervous system.
研究领域:
神经生物学
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医学影像学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2026
·
IF 15.6
Guolong Sun,Yijin Chen,Xiaoli Xia,Yiwen Wang,Jiejun Zeng,Jie Zhu,Lina Gao,Luming Peng,Linjun Wang,Xueqian Kong,Yizheng Jin
The surface hydrogen species of zinc oxide (ZnO) nanocrystals, including hydroxyl groups and water, play critical roles in determining their chemical reactivity, colloidal stability, and optoelectronic properties. However, direct structural identification of these surface species remains challenging due to their complex nature and surface disorder of the nanocrystals. Here, we present a comprehensive analysis of surface functionalities on sol–gel synthesized ZnO nanocrystals using advanced multinuclear and multidimensional solid-state nuclear magnetic resonance (NMR) spectroscopy, combined with density functional theory (DFT) theoretical calculations. By employing 1H, 7Li, 13C, 17O, and 31P NMR, alongside the use of deuterated precursors, 17O isotope labeling, probe molecules, defect analysis, and electron paramagnetic resonance (EPR) spectroscopy, we resolve and assign eight distinct hydrogen species, including acetate and lithium acetate ligands, chemisorbed and physisorbed water, terminal hydroxyls (OHT), tribridged hydroxyls (μ3-OH), and defect-associated hydroxyls. Furthermore, 1H–1H homonuclear correlation SSNMR experiments elucidate the crystal facet selectivity and spatial interactions of these surface hydrogen species. Our study establishes an in-depth understanding of the rich surface hydrogen landscape on ZnO nanocrystals and offers a framework for the rational design and functional tuning of ZnO-based nanomaterials.
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PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2020
·Vol. 22
·期 44
·25760-25768
·
IF 3.43
Yaqing Wang,Wenjun Chen,Qi Zhao,Guizhen Jin,Zhimin Xue,Yingxiong Wang,Tiancheng Mu
Deep eutectic solvents (DESs) have attracted considerable attention due to their unique properties. Owing to similar structures and properties, DESs are also called “quasi-ionic liquids” or “ionic liquid analogous”. However, for a deeper understanding and application of DESs, a comprehensive investigation on the ionicity of DESs is crucial. In this work, the effects of the structure and components of typical DESs on the ionicity were investigated. Moreover, the ionicity was discussed by using Walden plot, and the validity of applying it to DESs was verified using pulsed field gradient nuclear magnetic resonance (PFG-NMR). We found that the lack of free charged species and high viscosities make it difficult to achieve optimal conductivities for DESs, and thus most of them exhibit “poor ionic” nature. Fortunately, with an in-depth understanding of its microstructure and physicochemical properties, the properties of DESs can be finely tailored by selecting or even designing suitable parent compounds for functional applications. In particular, the ionicity of Li-based DESs was investigated for their potential application as electrolytes in Li-ion batteries.
研究领域:
化学
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材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Qi Zhao,Yu Liu,Hui Ma,Yan Qiao,Jianbin Chao,Xianglin Hou,Yuqi Wang,Yingxiong Wang
Fischer-Tropsch (F-T) process is an important synthesis route to acquire clean liquid fuels through modern coal chemical industry, which converts syngas (CO and H 2 ) into hydrocarbon, and also generates oxygenates discharged as the F-T waste-water. These oxygen-containing compounds in F-T waste-water have the similar molecular weight and some are even isomers of each other. Hence, it is necessary to develop rapid and efficient analysis tools to obtain identification and quantitative information of the F-T waste-water. The pure shift NMR techniques provided only chemical shift information in one-dimension 1 H NMR spectra , without homonuclear J H-H coupling. In this work, we tested and compared three pure shift NMR techniques (including Zangger-Sterk, PSYCHE and TSE-PSYCHE methods) in the analysis of two F-T waste-water model mixtures, genuine waste-water and two alcohol isomer mixtures. The results show that J H-H coupling multiplicities are collapsed into singlets corresponding to individual chemically distinct protons of the compound. For some severely overlapped signals in the pure shift NMR spectra , the chemical shift selective filters with TOCSY (CSSF-TOCSY) experiments were conducted to assist the signal assignment. Thus, pure shift NMR approaches can identify most signals of components, and CSSF-TOCSY can extract the signal of a specific compound. The combination of these two NMR techniques offers a powerful tool to analyze the F-T waste-water or other complex mixtures including isomer mixtures.
研究领域:
化学
·
环境科学
·
能源科学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Xiaojia Yu,Ying Liu,Hui Wang,Weiguo Cheng,Youqing Wu,Suojiang Zhang
Brøsted acidic pyridinium-based ILs of [NS][CF 3 SO 3 ] and [NS][HSO 4 ] have been synthesized for oligomerization of isobutene with the excellent conversion of 92.8% and the good selective dimerization at the temperature of below 100 °C. Hydroxyl-containing materials, especially ethanol, could facilitate catalytic activities to excellent conversions of isobutene and 84.2% selectivity of diisobutene. [NS][CF 3 SO 3 ] could be recovered by a simple liquid-to-liquid separation and reused more than ten times without obvious loss of catalytic activities. The formation process of oligomers has been examined by in-situ NMR spectroscopy, and a step-by-step generation process of carbonium ions varying from C 4 + , C 8 + to C 12 + was proposed. The work behaves the significance of constructing a better catalysis system for highly selective dimerization of isobutene, and potential being scaled-up for industrialization.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）