Analytical Methods
·
2018
·Vol. 10
·期 41
·4978-4984
·
IF 2.073
Xing Huang,Kaipeng Zhang,Yanli Tong,Yongsheng Zhong,Zuanguang Chen
In this study, a gradient reverse phase high performance liquid chromatography combined with a capacitively coupled contactless conductivity detection (RP-HPLC-C4D) method for simultaneous determination of phospholipid and fatty glyceride in liposome was developed. After saponification, the fatty glyceride and two types of phospholipids were transformed into octanoic acid, palmitic acid and erucic acid, respectively, which were then separated and detected by RP-HPLC-C4D. The results showed good linearity in the range of 20–1000 μg mL−1 for octanoic acid and erucic acid and 10–1000 μg mL−1 for palmitic acid. The LODs of octanoic acid and palmitic acid reached 2.5 μg mL−1, and 10 μg mL−1 for erucic acid. The average recoveries of octanoic acid, palmitic acid and erucic acid were 100.2%, 102.9% and 101.4% (n = 9), respectively. The developed method could be effectively applied in the quality control and stability monitoring of liposome.
研究领域:
分析化学
·
药剂学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICS AND CHEMISTRY OF LIQUIDS
·
2013
·
IF 0.813
Jinshou Wang,Boan Shi,Zhen Shi,Yu Cao,Yingxuan Liu,Shenghui Zhang
We have measured the rate of saponification of ethyl acetate (CH3COOC2H5) in 2,6-lutidine (2,6-DMP) + water (H2O) near and far away from its critical point by electrical conductivity experiment. We found that the rate of saponification slowed in the one-phase region at temperatures near the critical point. This behaviour is evidence in support of critical slowing down. Moreover, the experimental results were compared with those of the same reaction in a different critical mixture of 2-butoxyethanol + H2O [Y.W. Kim, Int. J. Thermophys. 25, 1025 (2004)].
研究领域:
化学动力学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Minerals
·
2023
·Vol. 13
·期 10
·1322
·
IF 2.5
Xiaoliang Zhang,Yangge Zhu,Zhiqiang Zhao,Peilong Wang
Dolomite, a prominent calcium-bearing gangue mineral found in carbonate-type zinc oxide ores, poses a significant challenge for effective flotation separation alongside smithsonite due to their highly similar surface properties. The present study explores the potential of 2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctanoic acid (2-DMPT) as a collector for the reverse flotation of smithsonite from dolomite. Micro-flotation experiments indicated that saponified 2-DMPT exhibited superior collecting ability and selectivity for dolomite over smithsonite under highly alkaline conditions. Specifically, the flotation recovery of dolomite reached 62%, whereas only 6% of smithsonite was recovered in the flotation foam products. Zeta potential and attenuated total reflectance–Fourier transform infrared (ATR-FTIR) analysis revealed that changes in pH values had minimal influence on the collector’s adsorption onto dolomite, while significantly hindering its adsorption on the smithsonite surface. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis showed that 2-DMPT could form hydrophobic complexes with the active Ca2+sites on the dolomite surface at pH 11.5. However, the interaction between smithsonite and carboxylic groups of 2-DMPT under the same conditions was relatively weaker, facilitating their reverse flotation separation. As a result, 2-DMPT shows promise as a potential collector for the reverse flotation process, effectively removing dolomite from smithsonite and reducing acid consumption in subsequent acid-leaching processes.Keywords:smithsonite;dolomite;reverse flotation;highly alkaline conditions;saponified 2-DMPT
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2019
·
IF 6.395
Fujian Li,Yanliang Wang,Xiang Su,Xiaoqi Sun
Recycling schemes from rare-earth-containing scraps have been developed rapidly due to the increasing supply risk for rare-earth elements (REEs). This article aimed to reduce the ecological impact and reagent costs for separating and recycling REEs from scraps, i.e., spent ceria-based polishing powders and lutetium-based crystal waste. A simultaneous process was proposed using an industrial extractant Cyanex ® 572, which allowed efficient recycling of REEs from the wastes with less acid and alkali consumption than traditional hydrometallurgy process. Based on thermodynamic and kinetic analyses, common acid scrubbing was avoided by employing REEs scrubbing. Additionally, the alkali saponification, acid stripping and oxalic acid precipitation were substituted by one step of precipitation-stripping-saponification with ammonium fluoride which contained abundant F − in the solution with weak acidity. F − was easy to complex with REEs on the extractant as precipitate while NH 4 + bonded with anion of the extractant. Using this technique, the vast consumption of chemicals and million tons of wastewater in REEs industry may be avoided. Totally, the chemical consumption could be reduced over 80% and the wastewater was decreased more than 90%. REEs recovery yield also increased considerably using the novel process. Moreover, the ammonium fluoride was designed in containment system and was reused with no emission to the environment. This article provides a sustainable and efficient alternative process to REEs waste treatment industry.
研究领域:
冶金学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Mengjie Zhang,Xiangpu Jiao,Dezhang Ren,Chenxin Huang,Yang Li,Duofu Chen,Zhibao Huo
The rapid development of the biodiesel industry is of significant importance for achieving carbon emission reduction in the transportation sector. However, the presence of trace amounts of water in the feedstock during biodiesel synthesis may lead to severe saponification reactions, thereby reducing the yield of fatty acid methyl esters. In this study, based on our exploration of the characteristic of porous carbon to absorb moisture from the environment, we synthesized a CaO catalyst with porous carbon coating via discarded shrimp shell biomass. Because the carbonization temperature of organic matter in shrimp shells is lower than the decomposition temperature of CaCO 3 , the CO 2 generated during pyrolysis can erode the pyrolytic carbon and form porous structure. The mesoporous carbon shell facilitates the diffusion of oil and methanol molecules while adsorbing moisture in the alcohol phase. This structure effectively minimizes the interaction between CaO and water, thereby suppressing saponification reactions and ensuring the smooth progression of the desired transesterification reaction. Through a series of physicochemical characterizations, the structure and water absorption performance of the catalyst were confirmed. The as-prepared CaO@PC-900 catalyst demonstrated the ability to maintain a biodiesel yield of over 85% in a reaction system with a water content of 3%, significantly surpassing the performance of commercial CaO and previously reported Ca-based solid bases. This work provides a new approach to the design of anti-saponification transesterification catalysts, while also offering a novel pathway for the synthesis of porous carbon from discarded crustacean biomass.
研究领域:
能源科学
·
催化材料
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Liyi Zhang,Guangyong Zeng,Benkun Qi,Jianquan Luo,Yinhua Wan
Choline chloride-lactic acid, a common carboxylic acid-based deep eutectic solvent (DES), was used to pretreat corn stover (CS). Despite significant lignin and xylan removal, enzymatic cellulose conversion remained below 30 %, only slightly higher than untreated CS. Structural characterization confirmed esterification between the CS's hydroxyl groups and lactic acid during pretreatment. A brief 5-min saponification effectively removed these ester groups, leading to a 1.08-, 2.75-, and 2.50-fold increase in 48-h cellulose hydrolysis for 2-, 5-, and 8-h DES-pretreated samples, respectively. Analysis of chemical composition, surface morphology, crystallinity, and degree of polymerization revealed that these factors did not contribute to the enhanced hydrolysis observed in the saponified samples. This study concludes that saponification-induced de-esterification is the key factor driving the significant increase in enzymatic cellulose hydrolysis, highlighting the detrimental impact of esterification occurring during carboxylic acid-based DES pretreatment on subsequent cellulose saccharification.
研究领域:
生物化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2020
·
IF 2.952
Chang-Wei Zhang,Ming-Fei Li,Zhi-Wen Qi,Ran Tao,Jian-Zhong Ye,Xing-Ying Xue,Cheng-Zhang Wang
The aim of this work was to construct a new type of system for the green extraction and efficient separation of Ginkgo biloba leaf polyprenols (GBP). First, cell disruption technologies (enzymolysis, ultrasound, microwave and ball milling) coupled with deep eutectic solvents (DES) were used to extract polyprenyl acetates (PA) from Ginkgo biloba leaves. Results showed that ball milling was the best assisted extraction method, and the amount of PA was 89.88 mg/g. Then, a novel silver-loaded material with selectivity for PA was synthesized, characterized and utilized to absorb PA from the DES extraction solution. The purity of the PA quickly reached 71.28 % after being separated by the silver-loaded material. Finally, saponification and molecular distillation were adopted to remove non-GBP ingredients, and a high-purity GBP (99.80 %) was obtained by optimizing its processing conditions. This study provides a technical support for the development of a green and efficient GBP separation method and lays the foundation for the fabrication of GBP-based drugs, health products and cosmetics.
研究领域:
天然产物化学
·
药物分离与纯化
·
绿色化学
·
植物化学
·
分析化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yan Runhan,Cui Hongmin,Shi Jinsong,Yan Nanfu,Weng Yaqing,Cheng Ting,Wang Wei
There are still challenges in the recovery of rare earth elements (REEs) from leaching liquor of ion-adsorption type rare earth ore. In this paper, unsaponified N, N-di(2-ethylhexyl)-diglycolamic acid (HDEHDGA) was used to develop a green extraction process for efficient separation and enrichment of REEs. The cation exchange mechanism of RE(III) extraction was proposed by slope analysis and FT-IR spectra. HDEHDGA exhibited excellent extraction performances, such as short equilibrium time, high selectivity towards RE(III) and easy stripping by 0.5 mol/L HCl solution. REEs was enriched from 287.5 mg/L to 63.30 g/L by five-stage counter-current extraction and three-stage counter-current stripping using unsaponified HDEHDGA. The enrichment factor reached 220, and the proportion of REEs was increased from 80.76 wt% to 98.82 %. The loss of REEs was controlled below 2.14 wt%. This extraction strategy helps to improve the REEs recovery and avoid ammonia–nitrogen wastewater, which demonstrates its application potential in the ion-adsorption type rare earth ore.
研究领域:
化学工程
·
冶金工程
·
环境科学
✓ 已验证
DOI
高影响因子
HYDROMETALLURGY
·
2023
·
IF 4.7
Xintong Li,Yongna Guo,Xin Ma,Chao Zhang,Jia Yang,Shuai Wang
Herein, a series of α -hydroxyalkyl phosphinic acids were designed and first introduced in Mn 2+ extraction and Mn 2+ -Mg 2+ separation. The extraction tests indicate that the α -hydroxy-2-ethylhexyl phosphinic acid ( α -H-2-EHA) possesses superior extraction ability compared to di-2-ethylhexyl phosphinic acid (P204) for Mn 2+ and Mg 2+ , and the partition coefficient ( β ) is 28.2 at a saponification ratio of 30%. The results of quantum chemical calculation, FT-IR spectrum and slope analysis method reveal that the α -H-2-EHA can form stable four-membered ring structure with metal ions during the extraction process through P–OH and P O bonds. Furthermore, the HOMO composition results suggest that α -OH might also promote the interaction between extractant and metal ions. Finally, a three-stage countercurrent extraction—washing—stripping process was proposed and Mn 2+ can be enriched from 11.2 g/L to 36.6 g/L, with Mg 2+ decreased from 30.3 g/L to 0.6 g/L, which provides an efficient strategy for the preparation of high-purity manganese.
研究领域:
化学工程
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2023
·
IF 5.6
Yao Xiao,Zhenchun Xu,Chuansheng Wang,Huiguang Bian
In order to realize the high value-added utilization of natural clay materials in natural rubber composites , an environment-friendly animal glycerol potassium salt was introduced to modify kaolin, and the natural rubber with excellent performance were prepared by high-energy ball milling combined with gas-phase spray drying technology . The impact of the ball milling reduced the particle size and increased the specific surface area of kaolin, promoting the chemical modification of kaolin by potassium oleate. The gas-phase spray technology effectively broke the filler aggregates, and the high-temperature roller realized the instantaneous drying, reducing the oxidation and fracture of the rubber molecular chains . In this paper, the gas barrier properties , mechanical properties, anti-aging properties, dynamic mechanical properties and Payne effect of the composites were investigated. The FTIR , XPS and interfacial contact angle demonstrated the existence of a stable chemical bonding in the process of potassium oleate-modified kaolin, and the hydrophilicity of kaolin was reduced. Kaolin was uniformly and finely dispersed in the rubber matrix by spray drying technology. Compared with the traditional dry mixing, the composites prepared by the technology improved the gas barrier properties , processing properties, comprehensive mechanical properties, and the aging coefficient increased by 23.1%, and had excellent wet skid resistance and rolling resistance.
研究领域:
材料科学
·
化学工程
·
橡胶工业
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Ruihui Wu,Ronghao Liu,Xiaoxia Liu,Jianwei Zhang,Wenfeng Xue,Yanzhao Yang
The recovery of Nd(III) from NdFeB permanent magnets is gaining increasing attention. In the rare earth elements separation industry, wastewater produced through saponification has become a serious environmental problem. In this work, a novel non-saponification P350-N235 synergistic extraction system was established for the extraction of Nd(III) from nitric acid medium. Almost 100% of Nd(III) was extracted by using a P350-N235 system when the molar fraction (X) of P350 was 0.3. And the synergistic enhancement factor R max reached 60.03. Firstly, the effects of time, pH, volume ratio and other variables were investigated to determine the extraction behaviors. Response surface methodology (RSM) was used to optimize the extraction conditions. The mechanism of synergistic extraction was investigated by FT-IR, UV–vis, NMR methods and ESP maps, indicating that the composition of the extracted complex was Nd(NO 3 ) 3 ·(P350) 2.5 (N235) 2.5 . Then, the extraction thermodynamics and kinetics were also thoroughly investigated, the extraction process is demonstrated to be a spontaneously exothermic reaction. In the NdFeB leaching solution, the synergistic system showed excellent separation factor (β) for Nd/Sm (1.43), Nd/Gd (7.33), and Nd/Dy (9.81). Finally, after 5 cycles, the P350-N235 synergistic system maintained high extraction efficiency. In conclusion, this study overcame the saponification problem in traditional extraction techniques and proposed an environmentally friendly green extraction system.
研究领域:
环境科学
·
化学工程
·
材料科学
·
稀土元素分离
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2023
·Vol. 24
·期 4
·1211-1223
·
IF 2.5
Zhang Quanchao,Zhang Mengna,Wang Ming,Song Zhiqiang,Luo Honglin,Yang Zhiwei,Wan Yizao
A good vascular graft should have a biomimetic integrated layered structure and simultaneously facilitate the formation of endothelial cell monolayer and proliferation of vascular smooth muscle cells (SMCs). Herein, we report an integrated bilayered small-diameter vascular graft consisting of a dense inner layer of bacterial cellulose (BC) nanofibers and saponified cellulose acetate (SCA) microfibers and a macroporous outer layer of BC. The integrated bilayered graft is fabricated by a combined method of electrospinning, in situ biosynthesis, and laser ablation. Scanning electron microscopy (SEM) analysis confirms that the BC nanofibers run through the inner and outer layers, leading to an integrated bilayered graft, and average pore size in the outer layer is 225.4 μm. In case of the integrated structure, the bilayered graft shows the suture retention of 0.68 N and 0.54 N in the dried and wet states, respectively. In vitro hemocompatibility experiments show that the BC/SCA inner layer exhibits good hemocompatibility. Furthermore, the compact micro-nano-fibrous inner layer favors endothelialization, while the macroporous outer layer promotes growth and proliferation of SMCs, thus achieving control over specific cellular behavior in respective layers. The unique integrated bilayered vascular graft exhibits the required mechanics, good hemocompatibility and biocompatibility and thus holds great promise for use as a blood vessel substitute.
研究领域:
组织工程
·
生物材料
·
生物医学工程
✓ 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）