CRYSTAL GROWTH & DESIGN
·
2012
·
IF 4.72
Yan Yan,Jia-Mei Chen,Na Geng,Tong-Bu Lu
Four cocrystals of agomelatine with urea (1), glycolic acid (2), isonicotinamide (3), and methyl4-hydroxybenzoate (4) in 1:1 stoichiometry were successfully synthesized via six kinds of synthons. The structures of 1–4 were determined by the single crystal X-ray diffraction, in which 1–3 form two-dimensional hydrogen bonded frameworks between agomelatine and coformers, while 4 displays a one-dimensional chain structure. The results of differential scanning calorimetry measurements indicate that the melting points of 1–3 are between those of agomelatine and coformers, while the melting point of 4 is below those of agomelatine and coformer. After the formations of cocrystals, the solubility of agomelatine is much improved, and the solubility values of 1–4 in phosphate buffer of pH 6.8 are approximately 2.2, 2.9, 4.7, and 3.5 times as large as that of agomelatine Form II, and 1.6, 2.1, 3.4, and 2.5 times as large as that of agomelatine Form I. The solids of 1–4 can keep their crystalline forms in phosphate buffer of pH 6.8 for 3.5, 2.0, 6.0, and 15.0 h, respectively.
研究领域:
药学
·
晶体化学
·
药物化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2023
·
IF 1.9
Ting Hu,Yujun Wang,Jingwei Lin,Zhanyong Wang
Poly(butylene succinate) (PBS), poly(hexamethylene succinate) (PHS) and three kinds of poly(butylene succinate-co-hexamethylene succinate)s (P(BS-co-HS)s) were enzymatically hydrolyzed by Fusarium solani cutinase. The results showed that the characteristics of the enzymatic hydrolysis of these polyesters were mainly affected by crystallinity, thermal properties and the BS/HS ratio. The enzymatic hydrolysis rates of the polyesters are as follows: P(BS-co-HS52) ≈ P(BS-co-HS71) > PHS > P(BS-co-HS32) > PBS. Furthermore, with increasing HS content, both the degree of crystallinity (Xc) and melting temperature (Tm) of the polyesters first decreased and then increased. P(BS-co-HS52) and P(BS-co-HS71) had the lowest Xc and the lowest Tm, thus had the highest hydrolysis rate; this shows that the hydrolysis rate is affected by Xc and Tm. The results also showed that BS/HS ratio could affect the physical properties and degradability of polyesters. Thus, it is possible to prepare polyesters with various physical properties and degradability for different applications by adjusting BS/HS ratio. The crystalline and amorphous regions of the polyesters were both hydrolyzed, during which parts of the crystalline regions were converted into the amorphous regions. Finally, we found that the crystal structure and thermal stability of the polyesters were not affected by the enzymatic hydrolysis.
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2025
·
IF 9.8
Fengyi Yang,Yimin Xuan,Xianglei Liu
Eutectic salts are widely utilized as latent heat storage materials in various thermal energy storage and management applications. However, developing efficient and accurate methods to predict the thermophysical properties of molten salts and guide their design remains a significant challenge. This study focuses on thermal properties, constructing an element gene feature database, and introducing an integrated machine-learning strategy for the design, screening, and evaluation of eutectic salts. Marginal contribution analysis reveals that the melting point is primarily influenced by features related to structural stability, while the fusion enthalpy is strongly associated with features affecting atomic bonding strength. Based on these insights, five novel eutectic salts are designed and experimentally validated. Among them, NaCl-NaF (66.0–34.0 mol%) exhibits a melting point of 683.7 °C and a fusion enthalpy of 588.8 J/g. High-temperature testing demonstrates that the prediction accuracies for the melting point and fusion enthalpy of the five salts are 94.49 % and 95.01 %, respectively. This study presents an effective and efficient approach for the precise targeted design of novel eutectic salts, offering expanded possibilities and options for the efficient utilization of renewable energy.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2022
·
IF 4.132
Xian Luo,Weifeng Dai,Yi Qin,Shiyun Jiao,Baocai Li,Mi Zhang
Refined montan wax (RMW) is a lignite-based chemical product with wide application and high added value. However, research on its processing and performance is very limited. Currently, four parameters in the key preparation procedure for the oxidation bleaching of RMW, including the concentration of two oxidants (H2SO4 (P1) and CrO3 (P2)), oxidation time (P3), and the mass ratio of CrO3 used in two oxidation steps (P4), were systematically evaluated in regard to their impact on the properties and chemistry of RMW. The results showed that the four tested parameters visibly affected RMW, and each parameter had a different impact on the properties of RMW by range analysis, of which P1 showed a greater influence on its acid value; P2 influenced its friability, specific surface area, and aperture; P3 affected its color, initial melting point, and saponification value; and P4 had a higher impact on its final melting point, melting range, and hardness. Gas chromatography with flame ionization detection–mass spectrometry analysis revealed that the compounds found in RMW samples (RMWs) under different oxidation conditions differed significantly, with major differences in the content and amount of these components. Among the compounds in RMWs, 16 different compounds (variable importance of projection > 1) were found by the orthogonal projections to latent structures discriminant analysis method, nine of which have a strong relationship to the different performances of RMWs. This work provided a basis for the development of performance-oriented preparation processing technology for RMW.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 50
·36980-36988
·
IF 3.9
Xinyu Feng,Qi Xue,Junlin Zhang,Kaidi Yang,Kunkai Wang,Bozhou Wang,Fuqiang Bi
To modify the sensitivity and melting point of the casting of DNTF, a eutectic system of insensitive explosive 3,5,5-trinitro-1,3-oxazinane (TNTON) and DNTF was prepared through a new method. The melting and liquefaction processes of TNTON/DNTF at different ratios were investigated, and a T–x phase diagram was established. The melting and decomposition processes of TNTON, DNTF, and TNTON/DNTF eutectic at different heating rates were compared, while the sensitivity tests were conducted to study the desensitizing effect of TNTON on DNTF. Using EXPLO-5 software, the detonation performance of the TNTON/DNTF eutectic was calculated. The experimental results show that the stoichiometric composition of the TNTON/DNTF eutectic is 58.26 : 41.74, with an average melting point of 69 °C. With the increase of heating rate, both the melting and decomposition reactions are delayed. According to the activation energy (Ea) curve, the thermal decomposition is through an autocatalytic process. The impact and friction sensitivity of the TNTON/DNTF eutectic are 38 J and 252 N, respectively. Theoretical density of the TNTON/DNTF eutectic is 1.906 g cm−3, and the calculated detonation velocity is 8921 m s−1. The TNTON/DNTF eutectic exhibits good thermal stability and can significantly reduce the sensitivity of DNTF while maintaining its high energy level. The detonation performance of TNTON/DNTF low eutectic cast explosive is better than that of TNT based cast explosive.
研究领域:
化学工程
·
爆炸物科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Linhan He,Kaili Ling,Mingjie Wang,Xuejin Zhang,Jing Li,Yao Chen,Yongming Fan
This study highlights the significance of the difference between the melting and solidification temperatures of phase change materials (PCMs) in their practical applications. We incorporated the wood fiber as a support phase and used alkylation to modify the pore structure and surface properties of silica aerogels . The effect of different pore size distributions and surface properties on the phase change properties of PCMs was investigated. The results showed that nanopores increased pressure and the melting point of PCMs while the weak interaction force on the substrate surface decreased their solidification temperature. Furthermore, using matrices with unique properties, such as mesopore and hydrophobic aerogels , proved to be effective in reducing the difference between the melting and solidification temperatures by up to 44.1 % compared to pure paraffin wax. Moreover, hydrophobic groups enhanced the encapsulation performance of the composite, effectively isolating the influence of water.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Fei Xiao,Yanpei Guo,Rongjie Yang,Jianmin Li
A series of activated Mg-based alloys with low-melting-point metals (Zn, Sn, Bi, and In) are prepared by ball milling and characterized by scanning electron microscope and X-ray diffraction. Their hydrogen generation properties are systematically investigated in seawater and methanol. The results demonstrate that the addition of low-melting-point metals can significantly accelerate the reaction of magnesium with seawater and methanol. The alloy Mg-10%In exhibits the excellent hydrolysis properties among all the samples with the maximum hydrogen generation rate of 7.4 mL g −1 s −1 and the hydrogen conversion yield of 93% at 30 °C in seawater. The excellent hydrolysis performance of Mg-10%In can be attributed to its lower activation energy , lower corrosion potential , and higher corrosion current density. Moreover, the active preservation method of activated Mg alloys by coating dioctyl sebacate is studied.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Spectroscopy
·
2013
·
IF 0
Dandan Sun,Jiang Li,Qinghua Pan,Chaowei Hao,Guoqiao Lai
PA6/LiCl composites were synthesized by in situ anionic polymerization based on the interaction between the inorganic salts and PA6. Sodium hydroxide as initiator and N-acetylcaprolactam as activator were used in the preparation of PA6/LiCl composites with variety of LiCl content. X-ray diffraction (XRD) and differential scanning calorimeter (DSC) testing results showed that both of degree of crystallinity and melting temperature of the composites were decreased under the influence of LiCl. And the γ crystal phase proportion increased with increasing the LiCl content to appropriate amount.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
JOURNAL OF POLYMER RESEARCH
·
2022
·Vol. 29
·期 2
·1-9
·
IF 3.061
Song Tao,Wang Qingyin,Li Jianguo,Chen Xuejun,Liu Shaoying,Wang Gongying
A new copolyesters of poly(2-[4-(2-hydroxyethoxy)phenoxy]ethyl-co-1,4-cyclohexylenedimethylene terephthalate) (PHCT) with different compositions were synthesized from terephthalic acid, 1,4-cyclohexanedimethanol and hydroquinone bis(2-hydroxyethyl) ether (HQEE) via esterification-polycondensation reaction. The synthesized copolyesters were analyzed by 1 H-NMR, FT-IR, GPC, intrinsic viscosity, DSC, TGA and tensile testing, respectively. The 1 H-NMR and FT-IR analysis confirm the successful introduction of HQEE into poly(1,4-cyclohexylenedimethylene terephthalate (PCT) chains. The introduction of HQEE into PCT chains can effectively lower the melting point of PCT, making it easier to process. The glass transition temperature of PHCT is higher than 70 ℃ and it has the comparable thermal stabilities to PCT. In addition, introducing HQEE into PCT chains can effectively improve the molecular weights of PCT, thus imparting PHCT with better mechanical performance relative to PCT. The PHCT is a tough polymer, which owns the higher Young’s modulus (above 300 MPa), the higher tensile strength (above 39 MPa) and the higher elongation at break (above 226%).
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
FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Yue Wang,Lin Han,Wanying Yu,Weiping Zhao,Jinfeng Pan,Sangeeta Prakash,Xiuping Dong
The sturgeon fish skin gelatin (FG) could not form gelation for printing at room temperature and must be hold its shape at low temperature after printing due to low melting and solidifying temperature, causing certain energy loss. The purpose of this study was to investigate the effects of various types (κ-carrageenan: KG; λ-carrageenan: LG; ι-carrageenan: IG) and proportions of carrageenan on the gelation properties and melting temperatures of sturgeon skin gelatin blended system and realize 3D printability at room temperature. The results showed that the turbidity of the blended systems increased significantly with adding 0.4%–0.8% carrageenan. Meanwhile, when the additive concentration of KG was 0.4%, the highest gel strength was 104.02 g. And the hardness and adhesive of gel were 5.44 times and 5.37 times of that single gelatin sample when the concentration of KG reached 0.8%. When IG was added, the melting temperature of the blended system could be improved most obviously, followed by KG, while LG could improve least. In addition, the blended system with IG could form a more dense and uniform network structure. The results of thixotropy showed the gel formed by the blended system had certain thixotropy, but the lag circle area is small resulted in the insufficient shape stability after printing. Among them, the blended systems with 0.8% KG and IG received successfully 3D printing at room temperature. In short, carrageenan has a positive effect on improving the gelation properties and applying in 3D printing of the sturgeon skin gelatin system at room temperature.
研究领域:
食品科学
·
生物材料学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2022
·
IF 6.465
Yu Zhao,Zhengguo Zhang,Ziye Ling,Xuenong Gao,Xiaoming Fang
Thermal interface materials that possess high thermal conductivity and can reach low thermal impedance during service, are highly desirable for chip heat dissipation systems, especially when cooling high-power chips. Herein, a novel thermal pad was developed by combining low melting point alloy having metal-level thermal conductivity and liquid-like rheological property with expanded graphite possessing large pore volume and high thermal conductivity. Specifically, the alloy 62.5Ga21.5In16Sn was modified by the trace-oxidation method to obtain oxidized alloy, followed by adsorbing into expanded graphite and then molding and pressing to fabricate the thermal pad. It is found that the oxidation treatment resulted in the generation of refractory metal oxides Ga 2 O 3 and SnO 2 within the alloy, thereby preventing the leakage of the alloy from the composite thermal pad. Impressively, the optimal low melting point alloy/expanded graphite composite thermal pad, prepared at the oxidation duration of 24 min, expanded graphite mass fraction of 4 % and compact density of 3.125 g/cm 3 , reached a thermal conductivity of as high as 26.94 W/m·K and a thermal impedance of as low as 0.42 K·cm 2 /W, along with exhibiting a good shape-stability. More significantly, when employed into a simulative desktop CPU cooling system, this thermal pad exhibited 36.78 % higher cooling efficiency under the forced air convection, extended ten times in the time for the chip to reach the upper limit temperature (100 ℃) under the natural air cooling, and benefited to the chip to fight with the pulse-type instantaneous thermal shock, as compared to the commercial thermal pad. These excellent characteristics and good heat dissipation performance make the low melting point alloy/expanded graphite composite thermal pad show great potential for use in chip thermal management systems.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
高影响因子
Materials Advances
·
2023
·Vol. 4
·期 9
·2119-2126
·
IF 5
Ran Chen,Liang Zhao,Yannanqi Li,Jian Li,Pei Chen,Xinbing Chen,Zhongwei An
A series of tolane liquid crystals terminated by but-3-enyl with high performance (such as high clearing point, low melting point, high birefringence Δn, low viscosity γ1, and broad nematic phase interval) were designed and synthesized in accordance with the phase-only liquid-crystal-on-silicon (LCoS) device requirements for AR displays. The effects of the lateral fluoro-substituent, central alkyne bond, terminal group, and flexible n-alkyl chain on the thermal properties were systematically investigated, and density functional theory (DFT) calculations of molecular conformation and aspect ratio were used to corroborate the experimental results. Further, their properties of phase transition temperature, birefringence, and viscosity were comprehensively evaluated in two typical LC mixtures (001, P02-F). The results indicate that our target compounds can effectively lower the melting point, broaden the working temperature interval, and maintain a high Δn and low γ1 for three LC mixtures. One new LC mixture by employing compound 2TFV as a LC dopant exhibited a high Δn (∼0.26), moderate γ1 and dielectric anisotropy (∼6.3), and broad temperature adaptability (−31.3 °C to 91.3 °C), and achieved 2.08π phase modulation, 5 V operation voltage, and 2.89 ms response time at 40 °C in a reflective LCoS device.
研究领域:
材料科学
·
显示技术
·
光学
✓ 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）