JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2013
·Vol. 113
·期 3
·1297-1302
·
IF 1.982
Yan X.,Wang T. B.,Pei H. R.,Wang L. P.,Lan X. Z.
Phase behavior of dodecane–tridecane ( n -C 12 H 26 –C 13 H 28 , C 12 –C 13 ) mixtures in bulk and confined in SBA-15 have been investigated using differential scanning calorimetry. Bulk C 12 –C 13 system has a complicated behavior due to special rotator phase. It has been found that phase diagram of C 12 –C 13 /SBA-15 (3.8 nm) system is a straight line, C 12 –C 13 /SBA-15 (7.8 nm) a curve, and C 12 –C 13 /SBA-15 (8.9, and 17.2 nm) a loop line. The growth of the phase diagram shows size effect on phase behavior of C 12 –C 13 mixtures. Moreover, in the range of 3.8–17.2 nm melting temperatures of pure C 12 and mixtures at mole fractions x
C13 = 0.1–0.5 have linear relation with inverse pore diameter, while C 13 and mixtures at x
C13 = 0.6–0.9 present curved lines. The confined mixtures show a similar melting behavior with pure C 12 , C 13 .
研究领域:
物理化学
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材料科学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Wenrui Wan,Dazhen Xiong,Qian Zhang,Jianji Wang
It is very important to develop “smart” solvents that can integrate the advantages of homogeneous and heterogeneous reactions into one chemical process for enhanced reaction rate and minimal environmental impact. In designing these solvents, the applicability of the systems to real processes strongly depends on the phase behavior of the systems. In this work, a novel class of CO2-driven miscible–immiscible transition of deep eutectic solvents (DESs) has been explored. These DESs are composed of alkanolamine compounds as hydrogen-bond acceptors (HBAs) and phenolic compounds as hydrogen-bond donors (HBDs). They exhibit unique phase behavior with H2O: miscible with water in the absence of CO2 but immiscible with water in the presence of CO2 at room temperature and ambient pressure. Reversible liquid–liquid phase transition of such DES–H2O mixtures can be realized by alternative bubbling of CO2 and N2 under ambient conditions. Spectroscopic investigations show that the mechanism behind the miscible–immiscible transition of DESs involves breaking of the hydrogen bonds between HBDs and HBAs by H2CO3 generated by bubbling CO2 through an aqueous solution because the acidity of H2CO3 is stronger than that of HBAs. Further, the HBAs react with H2CO3 to form ammonium salts. The salting-out effect of ammonium salts leads to the formation of an ammonium salt-rich top phase and an HBD-rich bottom phase. When CO2 is removed by bubbling of N2, a reversible process is achieved.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
Journal of Physical Chemistry C
·
2014
·
IF 4.835
Li Ping Wang,Qi Feng Li,Chao Wang,Xiao Zheng Lan
Solid–liquid phase behaviors of the hexadecane–octadecane (n-C16H34–C18H38, C16–C18) system in the bulk, and confined in controlled porous glass (CPG) are investigated using differential scanning calorimetry and temperature-dependent powder X-ray diffraction. Bulk C16–C18 mixtures show the special rotator phase RI, and two intermediate phases with monoclinic (Mdcp) and orthorhombic (Op) structures. Inside CPG (8.1 and 300 nm), the RI and Op phases could be found in wider compositions of the solid mixtures than the bulk, however the Mdcp form was not observed. Unexpectedly, under the confinement of CPG (8.1 nm) not only the rotator RI appeared in the two pure components, C16 and C18, but a rotator phase RII occurred in the pure C18 and most of the mixtures upon heating. These new phase behaviors of the confined alkanes could be attributed to the size effect and the interface interactions. According to XRD analysis, in the small pores of CPG (8.1 nm) the alkane molecules effectively take the 2D arrangements. While in the large pores of CPG (300 nm), they take ordered packing to some extent both in the lamellar and lateral directions.
研究领域:
物理化学
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材料科学
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高影响因子
LIQUID CRYSTALS
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2022
·
IF 2.676
Xiang-Yu Ma,Qiu-Cheng Li,Cheng-Han Song,Hong-Shuang Zhang,Yuan-Sen Zhi,Xiao-Zhi He
Fluorescent liquid crystal polymers have attracted much attention because of the combination of fluorescence, liquid crystallinity and processability. In this study, we designed and synthesised two series of photoluminescent cholesteric liquid crystal polysiloxanes, which contained cholesterol mesogens and fluorescein methyl ester with different side chain lengths. The chemical structures and liquid crystal properties of the polymers were investigated by the usual methods. The photoluminescent property were characterised by fluorescence spectroscopy. At the same time, the effects of the lengths of the fluorescent group chains on the liquid crystal and fluorescence properties of the polymers were studied. The results showed that the synthesised polymers possessing very good fluorescent and liquid crystal properties, which may has certain practical value and application prospect.
研究领域:
材料科学
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化学
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DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Haoran Xu,Sheng Chen,Shaonan Chen,Rui Qiao,Hui Li,Hang Luo,Dou Zhang
When one considers that outstanding dielectric polymers satisfy the developed requirements in the electronic and electrical industries, it is necessary to explore the structure–property relationship of all-organic polymer dielectrics. In this paper, two kinds of side-chain sulfonyl-containing dipolar polymers based on polyolefin main chains, poly{2,5-bis[(4-(methylsulfonyl)phenyl)oxycarbonyl]styrenes} (PBSO2) and poly{2,5-bis[(4-(methylsulfonyl)ethyl)oxycarbonyl]styrenes} (PESO2), were prepared via radical polymerization. The effect of the side-chain structure on the phase behavior, phase structure, dielectric property, and energy storage of dipolar polymers was investigated. The results showed that PBSO2 possessed a high glass transition temperature (Tg ≈ 195 °C) and formed the columnar nematic phase owing to the rigid side-chain structure. A dielectric constant of 20.8 (25 °C, 103 Hz) was obtained for the polymer PBSO2 due to the highly orientational polarization and the possible interfacial polarization between the amorphous phase and liquid crystalline phase, which is 18% higher than that of PESO2. However, PBSO2 exhibited a low breakdown strength because of the low band gap of ≈3.46 eV and brittleness of the film. In contrast, a low Tg of 78 °C and isotropic phase were found in the polymer PESO2. In addition, a discharge energy density of 6.2 J/m3 at 270 MV/m was achieved, which was attributed to the high dipole density. This study indicates that it is effective to improve the dielectric constant by introducing a liquid crystalline phase into a dipolar polymer, which offers a route for synthesizing high-performance dielectric polymers.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2024
·
IF 11
Jingjie Hou,Hongyu Chang,Yufei Liu,Huajiang Zhang,Hanyu Li,Zhongjiang Wang,Ahmed M. Rayan,Mohamed Ghamry,Taha Ahmed Mohamed,Kuangyu Zhao
This study developed a dilution-phase diagram method to determine the phase behavior of concentrated egg yolk-carboxymethyl cellulose (EYCM). The results demonstrated that the strength of the electrostatic interaction (SEI) was within the strength limit (1314 mV 2 ), and selective patch binding dominated the formation of soluble complexes. An SEI beyond the strength limit of electrostatic repulsion dominated the formation of alkaline co-solubility. The complex coacervates were formed due to strong electrostatic attraction at SEI > −100 mV 2 . The acidic co-solubility was formed due to the protonation of carboxymethyl cellulose (CMC). Spectroscopic analysis revealed that the stability of the EYCM spatial structure of the soluble complex was due to the stabilized hydrophobic core, the low content of unstable irregular coils (23.12%) and the high content of highly stabilized β-sheets (24.36%). The different phase behaviors of EYCM affected the emulsification and gelation properties. The acidic and alkaline environments led to co-solubility of the EYCM of a smaller particle size (<362.7 nm), which exhibited a better emulsifying activity. A suitable particle size and depletion attraction improved the emulsification activity and stability of the soluble complexes. Although the complex coacervates had a larger particle size (4160.1 nm), the free CMC-induced depletion attraction contributed to the favorable emulsion stability. In addition, for alkaline co-solubility, the intermolecular folding of LDL, lipid filling and CMC enhancement of the gel framework to form a strong gel. As acidification proceeded, protein unfolding was restricted, the role of lipids and CMC was reduced, and the gel structure gradually diminished.
研究领域:
食品科学
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生物化学
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DOI
高影响因子
FLUID PHASE EQUILIBRIA
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2022
·
IF 2.745
Feng Liu,Li Chen,Kangling Yin,Taotao Fan,Zongcheng Yan
In this work, a novel liquid–liquid biphasic system of sugar-based deep eutectic solvents (DESs) was studied. The liquid–liquid biphasic system was formed when sugar-based DESs and n-propanol (NPA) showed incompatibility in an aqueous solution at above critical concentrations and 298.15 K. The DESs were prepared by choline chloride and sugars (sucrose, glucose, fructose, and xylose). The influence of the hydroxyl group and structure of HBD on the phase behavior was evaluated using phase diagrams and tie-lines length (TLL). Results showed that the biphasic region of DESs-based system was expanded by enhancing the hydrophilic of HBD. Each HBD (sucrose, glucose, fructose) and choline chloride can form ternary system with NPA and water. With this phase behavior, the molar ratio of DESs in two phases is the same as the original ratio of the DES formation. A non-random two-liquid (NRTL) model was used to correlate the tie-lines data of the systems, and the binary interaction parameters of the model were then obtained. Shikimic and vanillic acids used as biomolecule probes in two phases was studied to further explore the extraction potential of these DES-based systems. This work showed that the nature of HBDs influences the distribution behavior of shikimic and vanillic acids. And the DES-based systems presented higher extraction efficiencies (from 88.02% to 91.90%) for shikimic acid, which shows good extraction levels.
研究领域:
化学工程
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生物技术
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DOI
高影响因子
Journal of Chemistry
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2012
·
IF 0
Xiao Yan,Hai-Rong Pei,Tong-Bo Wang,Wen-Bo Liu,Xiao-Zheng Lan
Phase behavior of undecane-dodecane mixtures (n-C11H24-C12H26, C11-C12) in bulk and confined in SBA-15 (pore diameters 3.8, 7.8, and 17.2 nm) has been studied by differential scanning calorimetry. Phase diagram of the confined C11-C12 system shows dependence on pore size, indicating simple behavior compared with the bulk. In the three systems, melting points of the confined C11, C12 and the mixtures ( = 0.1–0.9) present a linear relation with the pore diameter from 3.8 to 17.2 nm. Melting behavior of the confined C11-C12 mixtures is closely as the confined C11, C12. Melting temperatures of the three systems have been fitted as a function of mole fraction .
研究领域:
材料科学
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物理化学
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2013
·Vol. 116
·期 1
·469-476
·
IF 1.982
Wang L. P.,Wang T. B.,Gao C. F.,Lan X.,Lan X. Z.
Phase behaviors of dodecane–hexadecane ( n -C 12 H 26 –C 16 H 34 , C 12 –C 16 ) binary mixtures in bulk and confined in SBA-15 (pore diameters 3.8, 9.5, and 17.2 nm) are investigated using differential scanning calorimetry. According to the thermal analysis, the bulk mixtures belong to a system of partial miscibility with two solid solutions and a eutectoid in the range of mole fraction \( x_{{{\text{C}}_{ 1 6} }} \) = 0.1–0.8. Under confinement, phase behavior of C 12 –C 16 mixtures is distinct from the bulk. Inside pores of SBA-15 (3.8 nm), the solid mixtures has only a melting boundary. In the pores larger than 9.5 nm, phase behaviors of the mixtures show some resemblance to the bulk system. The growth of the phase diagram with the pore diameter clearly shows the size effect on the phase behavior of the confined mixtures. In comparison with those of chain length difference of pure components of two carbon atoms or less, C 12 –C 16 mixtures exhibit different phase behaviors not only in the bulk but also in the confined state.
研究领域:
物理化学
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材料科学
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DOI
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2018
·Vol. 47
·期 6
·1037-1047
·
IF 1.401
Gao Jing,Liu June,Wei Yuanyi,Nie Fanghong,Ji Hongwu
Ionic liquids (ILs) based aqueous biphasic systems (ABSs) have been successfully applied to the extraction and purification of biomolecules. Although much research has focused on the effect of ILs on the phase formation, there are few reports that describe the phase behavior of quaternary IL-based ABS systems using amino acids (AAs) as additives. Here, 1-butyl-3-methylimidazolium tetrafluoroborate ([C 4 mim]BF 4 ) formed an ABS with sodium citrate (Na 3 C 6 H 5 O 7 ) with the aid of AAs. The phase behavior and physical properties of the ABS were investigated at 298 K. The capacity of the AA to create the ABS (area of biphasic region) increases with increasing in solubility and decrease with the molecular weight of the ILs and follows the trend glycine > l -alanine ≈ l -lysine > l -threonine > l -proline ≈ l -arginine > none. Moreover, the pH of the top and bottom phases containing l -proline as additive are nearly neutral; l -threonine, glycine, and l -alanine result in mildly acidic environments, while l -arginine and l -lysine provide basic pH conditions. The results show that the effects of the addition of the AAs can be considerable and important in the simulation, design calculation and pH control of ABS for efficient separation and extraction processes.
研究领域:
生物化学
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分离科学
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高影响因子
RADIATION PHYSICS AND CHEMISTRY
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2019
·
IF 1.984
Wei Qi,Mengjie Li,Long Zhao
Recently, controlled synthesis of nanoparticles through the use of microemulsions combined with electron-beam or γ irradiation has garnered interest. However, there are rare research about the effect of these radiations on the interfacial properties and phase behavior of microemulsions. Therefore, in this work, we prepared ionic liquid-based microemulsions (IL-C n -Ms) combining 3-methylimidazolium hexafluorophosphate having different alkyl chain lengths, TX-100, and deionized water and then irradiated them with a high-energy electron beam . The effects of radiation and alkyl chain length on microemulsion microregions, droplet size, surface tension, and solubilization were investigated in detail. Radiation had a negligible effect on the interfacial properties and phase behavior of the IL-C n -Ms. Interestingly, the droplet size of IL-C n -Ms increased with the alkyl chain length of the ionic liquid due to the IL interactions at the IL-C n -Ms interface. Our work provides a preliminary database and presents new opportunities for the combination of ionic liquid-based microemulsions and radiation technology.
研究领域:
化学
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材料科学
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辐射技术
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DOI
高影响因子
ChemNanoMat
·
2025
·
IF 2.6
Mingjun Tang,Min Ling,Wenjing Ma,Wenqian Sheng,Wenjun Yan
Microemulsions are extensively utilized in food, pharmaceuticals, and cosmetics due to their superior solubilizing capacity and protective capabilities. However, a longstanding critical issue with microemulsions is the quantitative relationship between the HLB value and the physicochemical properties. Herein, to quantify the effect of the HLB value on microemulsions, Juniperus chinensis Roxb. essential oil (CEO) microemulsions were fabricated. It is certified that HLB values between 8.5 and 11.5 correspond to the smallest biphasic regions, while values between 9.5 and 13.5 correspond to the largest monophasic regions. Besides, the phase evolution from lamellar structures to microemulsions was monitored by the Small-Angle X-ray Scattering (SAXS) patterns. The physicochemical properties of the resulting emulsions, e.g., polydispersity indices (PDI), zeta potential, thermal stability, viscosity, and conductivity, were also investigated. The quantification of the effect of the HLB value on the formation of microemulsions will provide significant quantitative and theoretical guidance to researchers and industry professionals.
研究领域:
药剂学
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食品科学
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化妆品科学
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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）