FLUID PHASE EQUILIBRIA
·
2021
·
IF 2.775
Maolin Li,Yumin Liu,Mengya Li,Zeren Shang,Mingdi Liu,Dandan Han
The solubility of kaempferol monohydrate (KFM) in five mono-solvents (ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol) and three binary solvents (ethanol + water, 1-propanol + water, 2-propanol + water) was measured by gravimetric method from 283.15 K to 323.15 K at the pressure of 0.1 MPa. It is concluded that solubility of KFM is a function of temperature and solvent composition. Statistical method was used to analyze the impact of physicochemical parameters of solvents on solubility of KFM, indicating that comprehensive factors, such as the hydrogen bonding donor capacity and cohesive energy density would influence on solubility of KFM. In addition, the COSMO-RS model was used to explore the effects of solvent-solute interactions on solubility of KFM. Further, the solubility data was correlated by the modified Apelblat equation, λh equation, and van't Hoff equation, in which the modified Apelblat equation showed the best correlation result. In the final, the apparent thermodynamic properties ( Δ sol H 0 , Δ sol G 0 , Δ sol S 0 ) of KFM were derived through the van't Hoff equation, demonstrating the dissolution process of KFM in the selected solvents was endothermic. We hope the solubility of KFM determined in this work provides data can support for its further purification.
研究领域:
化学工程
·
药学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2021
·Vol. 23
·期 48
·8588-8600
·
IF 3.545
Jing Zhang,Wenjun Zhang,Christine V. Putnis,Lijun Wang
As one of the most ubiquitous biominerals, calcium oxalate (CaOx) exhibits different hydrate phases. Although the monohydrate (whewellite, COM) is the thermodynamically favorable phase at ambient temperatures, the metastable dihydrate (weddellite, COD) can still stably exist in pathological mineralization but the stabilization mechanisms remain unclear. Herein, the in situ phase transformation of nano-sized COD to COM in the presence of citrate (CA) and zinc ions (Zn2+) as stabilizers was observed by time-resolved atomic force microscopy (AFM) and Raman spectroscopy. By a combination of zeta potential measurement, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), we demonstrate that CA can form a protective layer on the surface of nano-sized COD crystals to inhibit aggregation and delay the phase transformation of COD to COM. Due to the stabilizing/destabilizing effect of CA on the specific faces of COD, atypical-shaped COD crystals form. In addition, Zn2+ can substitute Ca2+ sites within the COD unit cell, shrinking the COD structure by compressing the “zeolite-like” channels to reduce weakly-bonded interchannel H2O molecules. This generates relatively smaller and more stable COD crystals with a typical pyramid shape to further retard COM formation. The obtained results provide new insights into modulating the stability of the metastable CaOx phases for potential control over pathological mineralization.
研究领域:
生物矿化
·
病理学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2016
·Vol. 4
·期 3
·1600862
·
IF 3.365
Cunlong Yu,Cunming Yu,Liying Cui,Zhiyang Song,Xinyu Zhao,Ying Ma,Lei Jiang
Nowadays, oily wastewater and spilled oil have caused great threats on both ecosystem and human life. To address these severe problems, considerable efforts have been possessed on developing novel oil/water separation materials. The porous oil-absorbent materials, especially the porous polydimethylsiloxane (PDMS) with excellent properties of easy fabrication and inherent hydrophobicity, have attracted tremendous attentions from worldwide. The conventional methods using salt or sugar as sacrificial template and water as solvent have been widely adopted to fabricate the porous PDMS sponge. Due to the inherent hydrophobicity of PDMS, the solvent of water hardly penetrates into the inside of PDMS, which results in the difficult and incomplete remove of the hard template. In this contribution, the 3D interconnected porous PDMS sponge is facilely prepared by utilizing a modified technique with the citric acid monohydrate as hard template and ethanol as solvent. The proposed approach is capable of removing the hard template efficiently and thoroughly, which demonstrates promising utilizations in practical applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2018
·Vol. 23
·期 6
·1440
·
IF 3.098
Haoling Gao,Jiangang Yu,Chengsheng Ge,Qun Jiang
Optically pure sitagliptin phosphate monohydrate is efficiently and practically synthesized through a chiral hemiacetal as the key intermediate in 54% overall yield starting from (E)-4-(2,4,5-trifluorophenyl)but-2-enal andN-boc-protected hydroxylamine. The chiral hemiacetal fragment is constructed by a tandem aza-Michael/hemiacetal reaction catalyzed by an organocatalyst and the influence of acidity of Brønsted acid on tandem aza-Michael/hemiacetal reaction is researched in detail.Keywords:sitagliptin phosphate monohydrate;aza-Michael/hemiacetal reaction;asymmetric synthesis
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Zeren Shang,Mingchen Li,Baohong Hou,Junli Zhang,Kuo Wang,Weiguo Hu,Tong Deng,Junbo Gong,Songgu Wu
With the high-quality requirements for cephalexin monohydrate, developing a robust and practical crystallization process to produce cephalexin monohydrate with good crystal habit, appropriate aspect ratio and high bulk density as well as suitable flowability is urgently needed. This research has explored the influence of ultrasound on crystallization of cephalexin monohydrate in terms of nucleation mechanism and crystal habit control. The results of metastable zone width and induction time measurement showed the presence of ultrasound irradiation can narrow the metastable zone and shorten induction time. Cavitation phenomena generated by ultrasound were used to qualitatively explain the mechanism of ultrasound promoting nucleation of cephalexin monohydrate. Furthermore, on the basis of classical nucleation theory and induction time data, a series of nucleation-related parameters (such as crystal-liquid interfacial tension, radius of the critical nucleus and etc .) were calculated and showed a decreasing trend under ultrasound irradiation. The diffusion coefficient of the studied system was also determined to increase by 72.73% under ultrasound. The changes in these parameters have quantitatively confirmed the mechanism of ultrasound influence on the nucleation process. In further, the calculated surface entropy factor has confirmed that the growth of cephalexin monohydrate follows continuous growth mechanism under the research conditions of this work. Through the exploration of crystallization conditions, it is found that suitable ultrasonic treatment, seeding, supersaturation control and removal of fine crystals are conducive to improving the quality of cephalexin monohydrate product. Optimizing the crystallization process coupled continuous ultrasound irradiation with fine-crystal dissolution policy has achieved the controllable production of monodisperse cephalexin monohydrate crystal with good performance.
研究领域:
制药工程
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2024
·
IF 2
Wentao Chen,Yue Gui,Huayu Li,Xiran Shen,Xiaoli Liu,Fan Liu,Hong Chen
The solubility of calcium oxalate monohydrate (COM) has been measured in aqueous solutions of various naturally sourced organic small molecules such as carboxylic acids, amino acids, and polyphenols. All of these compounds enhanced its solubility, with carboxylic acids such as citric and malic acid exerting the most pronounced impact, within the addition concentration range of up to 100 μM. The observed solubilities were well correlated at all concentrations using a theoretical model that incorporates the specific interaction theory (SIT) specifically developed for this system. The complexation of these molecules with calcium ions was found to play a major role, which is subject to the material and charge balance. The induction time was also measured and found to increase with all of the compounds studied, suggesting their capability to bind with calcium.
研究领域:
生物化学
·
医学
✓ 已验证
DOI
高影响因子
JOURNAL OF PHARMACEUTICAL SCIENCES
·
2023
·
IF 3.8
Shizhao Ren,Fanglin Nian,Xiuzhi Chen,Rongrong Xue,Fenghua Chen
Two routes of the dehydration process of theophylline monohydrate have been proposed in this work from mid-frequency Raman difference spectra (MFRDS) results and experiments. MFRDS can establish short-range order correlations among various theophylline crystal forms. MFRDS results indicate that the short-range order of metastable Form III is most similar to that of monohydrate, which explains that Form III is the main dehydration products in the mild dehydration process. The phenomenon that unstable amorphous theophylline intermediate phase would appear during the dehydration process of theophylline monohydrate was confirmed indirectly by Powder X-ray Diffraction (PXRD) and optical microscope and reported in the previous reports, which could cause the nucleation of Form II, as MFRDS results indicate short-range order of amorphous solid dispersion of theophylline is most similar to that of Form II. MFRDS analysis shows the advantages in studying the phase transformation of small organic molecule crystals.
研究领域:
药学
·
光谱学
·
晶体化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2025
·
IF 5.8
Shu Jiang,Jinhua Wang,Jiaqi Chen,Xiaotong Huo,Yongkang Cao
Choosing proper cementitious material for the restoration of stone relics with high strength is challenging. In this study, a novel chemically bonded phosphate ceramics (CBPCs) was prepared based on acid-base reaction adopting metakaolin (MK) and monocalcium phosphate monohydrate (Ca(H 2 PO 4 ) 2 ·H 2 O, MCPM). The reaction products mainly consist of brushite (CaHPO 4 ·2H 2 O) and phosphorus‑aluminum silicate gel phase. In which, the appropriate amount of brushite can fill the gap in the gel phase, favoring more densified microstructure and higher mechanical performance. Notably, the activated alumina in metakaolin is the key reaction component, and the P/Al molar ratios affect the compositions and properties. Besides, the physicochemical properties of the product are comparable to stone matrix. Further, the concentration of the undesirable soluble salt ions is less than 7 % of ordinary Portland cement, which can effectively avoid salt damage and guarantee the applicational safety of the stone relics.
研究领域:
材料科学
·
文物保护
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Shuai Yu,Zihao Wang,Yuanchang Ma,Fumin Xue
Natural polymer additives including ethyecellulose (EC), hydroxy propyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC), and sodium lignin sulfonate (SLS) were selected to modify the crystal form and morphology of clozapine crystals. The effects of cooling crystallization, anti-solvent crystallization and additives on clozapine crystal morphology were studied. The type of additive has an obvious effect on the morphology of crystal, while the dosage of additive has a great effect on the average particle size of crystal. Medicinal crystal form of clozapine anhydrate can be obtained after enhanced drying of clozapine monohydrate. Clozapine crystal particles with controllable crystal form, morphology and particle size can be prepared by anti-solvent crystallization method with additive. To further explore the mechanism of natural polymer additives on morphology regulation, molecular simulation was used to analyze the interaction between the main crystal surface, solvent and additives.
研究领域:
药学
·
材料科学
✓ 已验证
DOI
高影响因子
ADVANCES IN POLYMER TECHNOLOGY
·
2018
·Vol. 37
·期 8
·2859-2865
·
IF 2.073
Qiuying Li,Tenghui Chen,Lewen Sun,Weihong Guo,Chifei Wu
This work aimed at providing a suitable method for preparing the cross-linked ultra-high-molecular-weight polyethylene (UHMWPE). First, UHMWPE was grafted with a silane compound using organic peroxide as an initiator in the molten state. Then, cross-linking was performed by compression molding of the mixture of the silane-grafted UHMWPE and CaC 2 O 4 ·H 2 O. Water released from CaC 2 O 4 ·H 2 O made the silane-grafted UHMWPE cross-link. In particular, no catalyst was added in the cross-linking step. Fourier Transform Infrared results confirmed that the silane has been grafted onto the UHMWPE chain successfully and the grafting index varied with the dosage of the initiator. With the increasing of CaC 2 O 4 ·H 2 O content, the gel ratio increased and average molecular weight of the cross-linked UHMWPE decreased, which proved that the cross-linked UHMWPE can be prepared by this method. Moreover, there existed different cross-linked network structures (loose and tight networks) in the samples with the same gel ratio.
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
APPLIED THERMAL ENGINEERING
·
2017
·
IF 3.444
Shijie Li,Hongyu Huang,Xixian Yang,Yu Bai,Jun Li,Noriyuki Kobayashi,Mitsuhiro Kubota
Lithium hydroxide monohydrate was modified by impregnation method with hygroscopic materials, such as polyethylene glycol (PEG), lithium chloride (LiCl), 13X-zeolite and NaY-zeolite. The lithium hydroxide monohydrate particles were well dispersed into nanoscale as composed with 13X-zeolite and NaY-zeolite. These composite materials exhibited obviously improved heat storage capacity and higher hydration rate than pure lithium hydroxide monohydrate, and the introduction of hygroscopic materials leads to greatly decreasing of apparent activation energy for the thermochemical reaction process. It is probably due to that hydrophilic materials provide efficient hygroscopic reaction interface and also show catalytic effect to the hydration reaction. Among these thermochemical materials, LiOH·H 2 O/13X-zeolite showed the lowest apparent activation energy (21.5 kJ/mol) and the highest heat storage density (1949 kJ/kg), which is 2.9 times higher than the pure lithium hydroxide after the same hydration time.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Xia Zhang,Qiuxiang Yin,Wei Du,Junbo Gong,Ying Bao,Meijing Zhang,Baohong Hou,Hongxun Hao
The crystal structures of monohydrate and anhydrous substance were determined from the single crystals for the first time. The phase transformation between anhydrate and monohydrate of sodium dehydroacetate was in situ investigated by using Raman spectroscopy. The mechanism of the phase transformation was proposed. The results showed that the monohydrate crystalline phase of sodium dehydroacetate can transform to anhydrous phase through solid–solid transformation upon heating or solution-mediated phase transformation. From powder X-ray diffraction (PXRD) patterns and thermal gravimetric analysis (TGA) data, it was found that the anhydrous crystals obtained by these two methods are the same in structure. However, the scanning electron microscopy (SEM) results revealed that the surface of the anhydrous sodium dehydroacetate crystals obtained by high-temperature dehydration was much rougher than that obtained by solution-mediated phase transformation. Furthermore, the dynamic vapor sorption (DVS) results showed that the anhydrous crystals with rough surface had faster hydration rate than the anhydrous crystals with smooth surface when increasing humidity. The reasons behind these phenomena were discussed.
研究领域:
药物化学
·
晶体学
·
药剂学
·
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）