CHEMICAL PAPERS
·
2021
·Vol. 75
·期 5
·1949-1958
·
IF 2.097
Zou Heng,Cao Qin-bo,Liu Dian-wen,Chen Xiu-min,Jiao Yong
Abstract Improving the collecting ability of a collector is a crucial issue in phosphate flotation. In this work, ricinoleic acid (RA) was used as a collector for fluorapatite (FA, Ca 5 (PO 4 ) 3 F) flotation. There is an OH group in the middle of the RA molecule, and thus, hydrogen bonds (H-bonds) can be formed between RA species. The role of the H-bond between RA molecules in FA flotation was revealed by experimental and theoretical calculation methods. The flotation results suggested that RA was more efficient than oleic acid for FA flotation at pH 9. The RA − anion was chemisorbed onto the negative FA surface, forming calcium ricinoleate (Ca(RA) 2 ) precipitates. The crystallization of Ca(RA) 2 on the FA surface was aided by the H-bonds between RA species. On the other hand, the results of quantum chemistry calculations showed that the H-bond in Ca(RA) 2 resulted in the close packing of RA − anions. Such a packing structure may occur on the FA surface, which favors the formation of Ca(RA) 2 on the surface and FA flotation. Moreover, Ca(RA) 2 was more stable than calcium dioleate in solution, also contributing to the better flotation efficiency of RA. These theoretical calculation results clarified the beneficial effect of the H-bond between RA species on FA flotation at the atomic level. Graphic abstract
研究领域:
矿物加工工程
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 136
·期 6
·2363-2371
·
IF 2.209
Zhang Yue-Fei,Lin Xiang-Feng,Chen Shuai
A highly efficient compound nucleating agent of carboxylated graphene/calcium pimelate (Gra/CaPi) for isotactic polypropylene (iPP) was prepared. The structure of Gra/CaPi was investigated by Fourier-transform infrared spectroscopy. The effects of Gra/CaPi on the crystallization and melting behaviors and crystalline morphology of iPP were investigated by differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscopy. The results showed that CaPi and Gra were combined by chemical bonds, improved the dispersibility and nucleation ability of Gra in iPP. When the addition amount of Gra/CaPi in iPP was 0.3 mass%, the crystallization peak temperature was increased by 8.0 °C and the relative content of β -crystal in iPP reached up to 0.868 compared with that of pure iPP.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yanshan Ju,Peng Yang,Jiajun He,Shaochun Tang
Radiative cooling fabrics have gained significant attention for their ability to enhance comfort without consuming extra energy. Nevertheless, sweat accumulation on the skin and diminishing cooling efficiency usually exist in the reported polymer cooling membranes. Herein, we report a universal method to obtain a calcium (Ca)-salt-enhanced fiber membrane with high infrared emission and hydrophilicity for efficient passive cooling and flame retardancy. The modification by Ca salts (including CaSiO3, CaSO3, and CaHPO4) with strong infrared emission results in an improvement in hygrothermal management ability, especially for moisture absorption and perspiration regulation in hot and humid environments. As an example, the CaSiO3@PMMA fiber membrane exhibits exceptional reflectivity in the solar spectrum (∼94.5%), high emittance in the atmospheric window (∼96.7%), and superhydrophilicity with a contact angle of 31°. Under direct sunlight, the CaSiO3@PMMA membrane exhibits an obvious temperature drop of 11.7 °C and moisture management achieves an additional cooling of 8.9 °C, as further confirmed by the ability to reduce the rate of ice melting. Additionally, the composite membrane provides notable flame retardancy and UV resistance. This work paves a new path in developing new materials with perspiration management and flame retardancy for zero energy consumption cooling in hot and humid environments.
研究领域:
材料科学
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能源工程
·
纺织科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Manzi Hu,Jingnan Lu,Hebao Mei,Honglie Ding,Kezhou Cai,Hui Zhou,Baocai Xu
Benzo[ a ]pyrene (BaP), known for its carcinogenic and mutagenic properties, is a marker of polycyclic aromatic hydrocarbons (PAHs). This study aimed to investigate the effect of partially replacing sodium chloride with different calcium salts (calcium chloride, calcium gluconate, calcium citrate, and calcium lactate) on BaP formation in barbecued pork sausages. The results revealed that all four calcium salts inhibited BaP formation in barbecued pork sausages ( P < 0.05). Specifically, calcium gluconate showed the most significant effect on BaP inhibition, with an inhibition rate of 61.82 %. Furthermore, calcium salts were found to inhibit lipid oxidation in barbecued pork sausages while promoting the Maillard reaction. Further validation experiments used resveratrol and sodium sulfite as lipid oxidation and Maillard reaction inhibitors, respectively. These results indicated that lipid oxidation is the primary pathway for BaP production in barbecued pork sausage and that the addition of calcium salts can effectively block this process.
研究领域:
食品科学
·
毒理学
·
营养学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2018
·
IF 1.666
Ying Zhang,Hongquan Yin,Qingshan Zhang,Yunzheng Li,Pengjun Yao,Hongyu Huo
Polyaspartic acid is a green biodegradable antiscalant and widely applied in water treatment field. However, its scale inhibition efficiency is not prominent, especially for calcium orthophosphate. So we introduced acylamino and hydroxyl groups simultaneously to prepare a novel polyaspartic-acid derivative (PASPTU) with multifunctional groups by the reaction of polysuccinimide with threonine and urea. The graft copolymer was analyzed by using nuclear magnetic resonance, gel permeation chromatography, thermogravimetric analyzer and Fourier transform infrared spectroscopy. Its scale inhibition performance for calcium orthophosphate, calcium sulfate and calcium carbonate was evaluated. The findings showed that the scale inhibition rates of the graft copolymer reached up to 100% for calcium orthophosphate, 100% for calcium sulfate and 91% for calcium carbonate at certain dosages. The findings above showed that the copolymer had excellent scale inhibition efficiency for calcium salts in water treatment processes.
研究领域:
材料科学
·
水处理技术
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2022
·Vol. 34
·期 1
·377-385
·
IF 3.348
Li Xie,Jin-Rong Zhong,Yan Li,Yue-Fei Zhang
The reaction precursors pimelic acid (Pi) and calcium stearate (CaSt) were added in situ during extrusion of isotactic polypropylene (iPP) to generate self-dispersed calcium pimelate (CaPi[IS]). The results reveal that the nucleating agents (NAs) synthesized in situ obviously affected the nucleation effect in iPP. The crystallization, mechanical properties and melting behavior of nucleated iPP were investigated. The crystallization temperature ( T c ) of iPP modified with CaPi(IS) increased by 4–5°C when compared to that of pure iPP. Especially, when the addition amount of CaPi(IS) in iPP was 0.30 wt%, the relative β-crystal concentration of iPP/CaPi(IS) reached the highest level of 96.47%, 22.71% higher than that of iPP/CaPi. However, Pi and CaSt has hardly impact on the nucleation effect in iPP. The mechanical properties of iPP show that CaPi and CaPi(IS) have excellent toughening effect on iPP while Pi and CaSt greatly improved the stiffness of iPP. Furthermore, the dispersion of these NAs in iPP was investigated by scanning electronic microscope (SEM). It can be clearly seen that the CaPi(IS) particles are uniformly distributed in the iPP after magnification.
研究领域:
材料科学
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聚合物工程
✓ 已验证
产品关联
DOI
高影响因子
Applied Sciences-Basel
·
2020
·Vol. 10
·期 7
·2617
·
IF 2.474
Shan Lu,Xinwei Wang,Tianzheng Wang,Xinran Qin,Xilin Wang,Zhidong Jia
The composition of contamination deposited on transmission line insulators can affect their surface flashover voltage. Currently, there is no rapid on-line method to detect this contamination composition in power grids. In this paper, we applied laser-induced breakdown spectroscopy (LIBS) to analyze contamination on insulator surfaces. Usually, Na and Ca salts are found in contamination along with various sulfate, carbonate, and chloride compounds. As an element’s detection method, LIBS can only measure a certain element content, for example, Ca. The mixture of various compounds with the same cations can influence the LIBS signal. The influence of mixing ratios on the calibration curves and relative spectral intensity was studied via LIBS. Na2CO3, NaHCO3, CaSO4, and CaCO3samples containing different proportions of Na and Ca were prepared. The linear correlation coefficients (R2) for the Na and Ca calibration curves generated using various mixing ratios were analyzed. The results showed that the mixture ratio did not dramatically affect the linear calibration curves for mixtures containing the same cations. This finding may significantly reduce the difficulty of applying LIBS analysis for complex contamination on insulators. The laser energy density had effects on the spectral characteristics of the measured elements. The partial least-square regression (PLSR) model can improve the accuracy of Na and Ca prediction.
研究领域:
电力工程
·
光谱学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Luhan Yang,E. Shuang,Jianglong Liu,Kuichuan Sheng,Ximing Zhang
Water hyacinth is a major aquatic plant in ecological restoration which propagates rapidly, whereas its biomass waste lacks value-added utilization routes. To address this problem, we put forth an innovative two-step carbonization strategy to convert water hyacinth to catalyst for isomerization of glucose to fructose. Through combining the hydrothermal carbonization and pyrolysis , catalyst morphology including its carbon substrate and calcium salts was successfully engineered. The prepared hydrochar-based catalyst presented an outstanding catalytic performance, the optimal of which could obtain 31% fructose yield with 89% selectivity at 120 °C for 45 min in water and maintain the reactivity for at least three runs. The catalytic reactivity was derived from the crystallization of endogenous alkaline earth calcium in water hyacinth, which was comparable to catalysts doped with expensive metals. Besides, the equipment and energy requirements for preparation were quite low-demanding (calcined only at 400 °C for 1 h). This study not only pioneers a sustainable way to upcycle aquatic biomass, but also invents a low-cost and efficient catalyst for biorefinery through the production of engineered carbon.
研究领域:
环境科学
·
生物化学
·
催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Bao-Cheng Huang,Gui-Xiang Huang,Jun Jiang,Wu-Jun Liu,Han-Qing Yu
Carbon-based materials are recognized as promising candidates for pollutant degradation because of their environmental benignity. Massive and cost-effective production and efficient recovery of carbon-based catalysts are crucial to apply this technology. However, various nanostructured carbons with different dimensions are usually utilized as precursors while not considering their complex preparation procedures and the high costs of ingredients. Moreover, catalyst separation and recovery are not given sufficient attention. In this work, a calcium salt-assisted pyrolysis strategy is proposed to tune the catalytic site formation of carbon-based catalysts. Results show that blending equal amounts of Ca2+ (calcium chloride) and organic precursors could greatly improve the catalytic activity of the carbonated product to activate peroxymonosulfate for pollutant degradation. In addition, the proposed synthetic strategy is universal to most of the readily accessed and cost-effective organic precursors. Singlet oxygen is identified as the main reactive oxidant for pollutant removal in the catalytic reaction. By cross-linking calcium ions and alginate as a hydrogel to immobilize the catalyst, the carbon material could be readily recovered. Furthermore, a long-term continuous-flow reactor test is conducted to validate the effectiveness of applying the immobilized catalyst to treat a synthetic wastewater with 0.5 mM bisphenol A. As a result, a green synthesis and immobilization strategy for persulfate catalysts is successfully established, and the prepared catalyst might be applied for wastewater treatment through using calcium salt in two purposes.
研究领域:
环境科学
·
催化材料
·
废水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Daqi Li,Shaocong Pang,Yang Xuan,Yuxiu An
When the well bottom temperature rises owing to increased well depth and formation complexity, the inadequacies of naturally modified polymeric fluid loss agents were revealed one by one, and synthetic polymeric fluid loss agents emerged as the essential technology to handle these problems. Nanomaterials were gradually being employed to increase the performance of polymeric fluid loss agents. Through free radical polymerization of amide polymers with silica nanoparticles in aqueous solution, a novel nano-graft copolymer (AAN-g-SiO2) was prepared for usage as a water-based drilling fluid loss agent. Fourier transform infrared spectroscopy and thermogravimetric analyses were used to investigate the structural characteristics and thermal stability of the polymer chains. Then, 4% bentonite freshwater-based mud and different concentrations of NaCl/CaCl2-based mud were prepared and added to the fluid loss agent AAN-g-SiO2. Moreover, high-temperature aging was carried out, and the API filtration volume of base mud and rheological characteristics were assessed. The fluid loss agent was demonstrated to withstand a high temperature of 220 °C, with the freshwater-based mud filtration volume at this temperature being 13.25 mL. Also, at 180 °C, AAN-g-SiO2 could be resistant to calcium and salt. Finally, we addressed the mechanism of AAN-g-SiO2 filtration using scanning electron microscopy and zeta potential distribution. The results showed that the inclusion of AAN-g-SiO2 may increase the stability of the drilling fluid system, resulting in the production of a thin and dense filter cake with no folds or pores visible at the microscopic level.
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
Food Bioscience
·
2022
·
IF 5.318
Yang Hu,Mengling Zhang,Yu Zhao,Xia Gao,Juan You,Tao Yin,Shanbai Xiong,Ru Liu
To investigate the effects of different calcium salts on the physicochemical properties of myosin, the intermolecular interactions, particle size, surface hydrophobicity , reactive sulfhydryl group content and rheological properties of sliver carp myosin with the addition of four different kinds of calcium salts (CaCl 2 , calcium citrate (CC), nano-hydroxyapatite (HAP), tricalcium phosphate (TCP)) during gel processing were measured. The results showed that the addition of CaCl 2 promoted the unwinding of α-helix, the increase in hydrophobic interactions, the formation of disulfide bonds of myosin, and increased the viscoelasticity of myosin. While, the addition of calcium citrate (CC) enhanced the hydrophobic interaction between myosin molecules, and the viscoelasticity of CC-added myosin was second only to the CaCl 2 -added myosin. On the contrary, the addition of HAP and TCP interfered with the hydrophobic interaction between myosin molecules, and greatly reduced the viscoelasticity of myosin. In summary, calcium with high calcium release rate can improve the physicochemical properties of myosin, HAP and TCP with a very low calcium release rate interfered with the formation of myosin gelation . And it could be concluded that the calcium ions played a leading role in the physicochemical properties of myosin, the more calcium ion that the calcium salt can release, the better physicochemical properties the myosin were. Our work may provide an insight into the phenomenon why different kinds of calcium salts differ from each other on affecting the physicochemical properties of myosin during gel processing.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2024
·
IF 6
Tianyue Xu,Ke Wang,Junjie Zhang,Yongzhi Cheng,Jiale Wei,Rui Duan
6S-5-methyltetrahydrofolate calcium salt crystal form C (MTHF-CAC) is a stable form of active folate. Compared with folic acid, MTHF-CAC is unaffected by the polymorphism of genes for folate-metabolizing enzymes and can be directly absorbed by the human body. In this study, MTHF-CAC was characterized by XRD, FTIR, DSC, and TGA. The effects of temperature, light, pH, and freeze–thaw cycles on the stability of MTHF-CAC solution were studied. The protective effects of ascorbic acid (AA) and cysteine (Cys) on MTHF-CAC were investigated by HPLC. The retention rate of MTHF-CAC solution was 82.6% after 6 days of storage at 4 °C but only 0.8% after heating at 75 °C for 330 min. Under UHT conditions, AA and Cys exerted protective effects on MTHF-CAC. 120 μg/mL of AA and Cys increased the retention of MTHF-CAC by 89.9% and 85.3%, respectively. The protective effect of AA was better than that of Cys. The research on the characterization and stability of MTHF-CAC provided the basic information for its application in the food industry.
研究领域:
食品科学
·
生物化学
·
营养学
✓ 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）