POLYMER ENGINEERING AND SCIENCE
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2024
·Vol. 64
·期 8
·3488-3504
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IF 3.2
Lubing Xiang,Xi Yu,Aimin Xiang,Xiaoying Lu,Meng Zhang,Hongfu Zhou
In this work, porous poly (vinyl alcohol) (PVA) hydrogels with different pore sizes were fabricated using inorganic non-metallic porogens by an environmentally friendly method, providing a potential solution for the field of wastewater treatment. PVA hydrogels have gained much attention in the field of wastewater treatment due to their excellent adsorption performance and porous network structure. However, the employment of inorganic non-metallic salts as porogens for PVA hydrogels has received limited attention so far. In this study, porous PVA hydrogels were prepared by freeze-thawing and freeze-drying with sodium sulfate (Na 2 SO 4 ) and calcium carbonate (CaCO 3 ) as porogens. PVA-Na exhibited denser network structure with the concentration of Na 2 SO 4 solution increased, and the tensile stress was enhanced by about 45 times. Meanwhile, the tensile stress of PVA-Ca was improved significantly from 0.06 to 1.67 MPa, and the network structure became looser after adding CaCO 3 . Moreover, a comprehensive investigation was conducted on the adsorption performance of porous PVA hydrogel for Congo red (CR). Finally, five adsorption models were fitted to investigate the adsorption mechanism of porous PVA hydrogels, in which the maximum adsorption capacity of CR by PVA-Na-0.5 was predicted to be 215 mg/g by the Langmuir isothermal model fitting. Highlights The structure of PVA hydrogels was adjusted by Na 2 SO 4 and CaCO 3 , respectively. The tensile stress of PVA-Na with dense network structure increased 45 times. Compared to PVA-FD, swelling equilibrium time of PVA-Na reduced from 24 to 6 h. Equilibrium swelling rate of PVA-Ca declined by half in comparison to PVA-FD. Langmuir isothermal model predicted q max of 215 mg/g for CR by PVA-Na-0.5.
研究领域:
材料科学
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环境科学
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废水处理
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高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2017
·
IF 1.591
Xiwei Jing,Weiguang Gong,Zhongjun Feng,Xin Meng,Baicun Zheng
A series of comb-like copolymer poly(styrene-co-maleic anhydride)-graft-poly(ε-caprolactone) (SMA-g-PCL, SP) with variation in PCL side chain length and side chain density were synthesized and employed as an efficient dispersant for CaCO3 suspension in organic solvent. The effects of molecular structures of comb-like copolymer on adsorption, rheological behavior, and suspension stability were investigated systemically to elucidate the governing dispersing mechanism. The molecular structures of comb-like copolymer not only significantly influenced the adsorption behavior but also the rheological behavior and suspension stability. Calculations based on the scaling law and Flory theory made a profound understanding of the impact of the molecular structure of comb-like copolymer on dispersion property. The results revealed that the steric repulsive force was enhanced by increasing of side chain length or density. However, the surface area for one molecule on CaCO3 surface was also increased for its larger radius of the hemispheres of comb-like copolymer. This led to the worse activity of adsorption. The dispersion of CaCO3 was due to the synergistic effects of adsorption and steric hindrance effect, which resulted that the comb-like copolymer with moderate length and density of side chain presented the best dispersability.
研究领域:
高分子科学
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胶体与界面化学
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材料科学
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纳米复合材料
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2023
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IF 4.2
Tao Shen,Jiawen Wu,Qingya Liu,Zhenyu Liu
Conversion of calcium carbonate (CaCO3) to calcium oxide and methane (CH4) by renewable hydrogen is promising to retrofit the current CaCO3 decomposition processes in many industries and, at the same time, to replace their carbon dioxide emission by CH4 generation. This work studies CaCO3 hydrogenation by a liquid organic hydrogen carrier, 9,10-dihydrophenanthrene (DHP), and the catalytic effect of nickel carbonate (NiCO3) at 400 °C. It is found that NiCO3 in situ forms Ni particles of 200–900 nm in size that promote CH4 formation from CaCO3. At the NiCO3:CaCO3:DHP molar ratios of 1:10:55 and 400 °C, the total CO32– conversion, CH4 selectivity, and CH4 formation from CaCO3 are 89.5, 40, and 80.3%, respectively, in 40 min.
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高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Tao Pei,Feng Shi,Can Liu,Yi Lu,Xu Lin,Defa Hou,Shunxiong Yang,Jirong Li,Zhifeng Zheng,Yunwu Zheng
In this study, a novel nitrogen-doped magnetic Fe–Ca codoped biochar for phenol removal was successfully fabricated via a hydrothermal and coactivation pyrolysis method. A series of adsorption process parameters (K 2 FeO 4 to CaCO 3 ratio, initial phenol concentration, pH value, adsorption time, adsorbent dosage and ion strength) and adsorption models (kinetic models, isotherms and thermodynamic models) were determined using batch experiments and various analysis techniques (XRD, BET, SEM-EDX, Raman spectroscopy , VSM, FTIR and XPS) to investigate the adsorption mechanism and metal-nitrogen-carbon interaction. The biochar with a ratio of Biochar: K 2 FeO 4 : CaCO 3 = 3:1:1 exhibited superior properties for adsorption of phenol and had a maximum adsorption capacity of 211.73 mg/g at 298 K, C 0 = 200 mg/L, pH = 6.0 and t = 480 min. These excellent adsorption properties were due to superior physicomechanical properties (a large specific surface area (610.53 m 2 /g) and pore volume (0.3950 cm 3 /g), a well-developed pore structure (hierarchical), a high graphitization degree (I D /I G = 2.02), the presence of O/N-rich functional groups and Fe-Ox,Ca-Ox, N-doping, as well as synergistic activation by K 2 FeO 4 and CaCO 3 ). The Freundlich and pseudo-second-order models effectively fit the adsorption data, indicating multilayer physicochemical adsorption. Pore filling and π-π interactions were the predominant mechanisms for phenol removal, and H-bonding interactions, Lewis-acid-base interactions, and metal complexation played an important role in enhancing phenol removal. A simple, feasible approach with application potential to organic contaminant/pollutant removal was developed in this study.
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PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2021
·
IF 6.707
You Wu,Yangyang Duan,Juan Qiu,Xiang Gao,Houyi Ma
The aim of this work is to develop an eco-friendly pH-responsive intelligent coating with long-term corrosion protection by a convenient method. Herein, an eco-friendly and long-term pH-responsive intelligent anti-corrosion coating (BTA-CaCO 3 @TA coating) is fabricated through the addition of a hydrophilic pH-responsive release material (BTA-CaCO 3 @TA microspheres) into a waterborne epoxy resin coating. The electrochemical impedance spectroscopy results indicated that BTA-CaCO 3 @TA microspheres could endow the coating with long-term corrosion protection. The |Z| f =0.01Hz values of the BTA-CaCO 3 @TA coating after 130 days of immersion were still higher than those of the pure waterborne epoxy resin coating at the beginning of immersion. The excellent long-term protection performance was related to the good dispersibility of BTA-CaCO 3 @TA microspheres in the waterborne coatings, the TA conversion film and the BTA inhibitor protection film, which formed on the steel surface in situ. This synergistic strategy demonstrated its future application for protecting metals from corrosion.
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高影响因子
FOOD HYDROCOLLOIDS
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2014
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IF 4.28
Sha Cai,Meng Zhao,Yapeng Fang,Katsuyoshi Nishinari,Glyn O. Phillips,Fatang Jiang
Emulsification/internal gelation is an effective encapsulation method to protect probiotics from adverse environment. In this paper, microcapsules of Lactobacillus acidophilus CGMCC1.2686 were prepared by emulsification and gelation of alginate solutions with slow release of Ca 2+ ions from calcium carbonate (CaCO 3 ) and calcium disodium ethylenediaminetetraacetate (Ca-EDTA). Physical characterization of the two types of microcapsules showed that alginate-Ca-EDTA microcapsule was more uniform in size than alginate-CaCO 3 , with a span factor of 0.96 and 1.20, respectively. Mechanical measurements demonstrated that alginate-CaCO 3 microcapsule was more robust and elastic, which was supported by its denser structure as observed by electron scanning microscopy. Bacteria encapsulation yields in the two microcapsules were similar, 37.9% for alginate-CaCO 3 and 36.9% for alginate-Ca-EDTA. However, alginate-CaCO 3 microcapsule exhibited much higher cell survivals in both simulated gastric juice and bile salts solution (22.2% and 2.6*10 −2 %, respectively) than alginate-Ca-EDTA (7.1% and 0%, respectively), indicating a more effective protection of L. acidophilus CGMCC1.2686. The protection efficiency was discussed in relation to the mechanical properties of the microcapsules and the calcium sources used.
研究领域:
食品科学
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微生物学
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
·
IF 4.539
Khin Nyein Ei San,Tian Niu,Yun Fang,Hong Wang,Ye Fan,Yongmei Xia
Adsorption of fatty acids and soaps on solid surfaces is widely-used to modify solids but easy to be desorbed and forming soap scum in acidic and hard water. The admicelle of sodium conjugated linoleate (ASCL) on nano-CaCO 3 was applied to fabricate stable ASCL@CaCO 3 , via SCL bilayer adsorption followed by simple thermo-curing the conjugated double bonds of SCL within an admicelle to anchor the admicelle around a nano-CaCO 3 core. The structure, morphology, and properties of ASCL@CaCO 3 were characterized by FT-IR, UV, TG, TEM, and contact angle measurements. High internal phase Pickering emulsions of liquid paraffin in water with oil volume fractions up to 80% could be stabilized with 1 wt% of the ASCL@CaCO 3 as particle emulsifier . The stable SCL bilayer on the CaCO 3 surface brings variable surface affinity in response to Ca 2+ /pH/CO 2 triple triggers, endowing the ASCL@CaCO 3 to stabilize high internal phase emulsions, switch on/off Pickering emulsions, and even lead to emulsion inversion. Therefore, the triple stimuli-responsive properties of the ASCL@CaCO 3 can be effectively applied in emulsion preparation–separation and drug delivery systems.
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高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2021
·
IF 3.517
Jianfeng Guo,Juhui Liu,Haoran Qie,Feng Zhao,Catherine Hui Niu
Folate-modified carboxymethyl chitosan (FCMC) was made by folate acid as targeted group and attaching folate to carboxymethyl chitosan, and then, targeted FCMC/CaCO3 hybrid nanosphere were formed by self-assembly of calcium carbonate in FCMC solution. The physicochemical properties of the nanospheres were investigated by Fourier transform infrared spectroscopy, X-ray diffraction analysis, Brunauer–Emmett–Teller measurement and thermogravimetric analysis (TGA). The results showed that the FCMC/CaCO3 hybrid nanospheres were composed of calcite, vaterite and polysaccharides, and the content of organic compounds was 12.17%. Also, the structure performance of the hybrid nanospheres was analyzed. Besides, the effects of the hybrid nanospheres on the encapsulation efficiency, the drug loading content and the release behavior were also analyzed with the metformin (MET) as a model drug. Scanning electron microscope, Zeta potential analysis and UV–Vis were used to characterize the hybrid nanospheres. Under the conditions of FCMC/Ca2+ molar ratio of 4: 1 and reaction for 24 h, the achieved results showed that the spherical aggregates with regular morphology were obtained and the average particle size of the nanospheres was 207 nm. The specific surface area of the hybrid nanosphere is 27.06 m2·g−1 and the average pore diameter of the sample is 3.84 nm, indicating the presence of mesoporous structure in the sample. This mesoporous structure can supply potential space for adsorption of anticancer drugs. Additionally, the surface charge of the nanoparticles was positive and the entrapment efficiency was 83.32%. The hybrid nanospheres have a capability of effective pH-sensitivity controlled drug release. All the drug loaded hybrid nanospheres successfully sustained the release of MET at pH 7.4, only about 44.58% of the drug released in 6 days. While under acidic condition (pH 5.0) drug release was significantly accelerated, being over 98.85% of the drug released. The hybrid nanospheres demonstrated an excellent smart drug delivery behavior.
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PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Xiaojuan Zhang,Edouard Asselin,Zhibao Li
The precipitation of CaCO3 and its kinetics for the CaCl2–CO2–Mg(OH)2–H2O system were systematically studied to develop a novel process for eliminating solid and liquid waste from the Solvay soda process. The effects of operating conditions including temperature, CaCl2 concentration, flow rate of CO2, and stirring speed on the reaction kinetics were experimentally determined. The results revealed that low temperature, high CO2 flow rate, and fast stirring speed can accelerate the reaction rate, and the mass transfer of CO2 is the controlling step. An MSMPR crystallizer was used to obtain the experimental crystal size distribution (CSD). A simplified population balance equation (PBE) was used to correlate the parameters on the basis of supersaturation. The soda solid and liquid wastes discharged from the Solvay industry were used as raw material to test the new process and validate the methodology. The precipitated CaCO3 consists of calcite or aragonite with high purity and uniform CSD. A double-effect evaporative-cooling crystallization process to recover MgCl2·6H2O and NaCl was simulated with help of Aspen plus and the electrolyte-NRTL (ELENRTL) model, suggesting economic benefits.
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高影响因子
ENERGY
·
2021
·
IF 7.147
T.X. Xu,X.K. Tian,A.A. Khosa,J. Yan,Q. Ye,C.Y. Zhao
The CaCO 3 /CaO reversible reaction pair is a promising thermochemical energy storage (TCES) technology for concentrating solar power (CSP) plants. However, the reaction performance and cyclic stability of this reaction pair is compromised because of sintering. In this study, TiO 2 -doped in CaCO 3 /CaO TCES system are systematically investigated by synchronous thermal analyzer (STA). The reaction kinetics of decarbonation process with and without TiO 2 doping are compared in N 2 and CO 2 atmospheres. Furthermore, the performance of CaCO 3 /CaO TCES system is analyzed in a fixed-bed reactor for future application. It is found that doping TiO 2 can improve the anti-sintering ability and cyclic stability of CaCO 3 , and the optimal doping ratio is 2.5 mol %, whose energy storage density is 1256.68 kJ/kg sample at first and improved by 2.26 times after 30 cycles. Moreover, doping TiO 2 decreases the activation energy and initial decarbonation temperature in CO 2 atmospheres. In exothermic experiments of fixed-bed reactor, the maximum exothermic temperature difference is 309.83 °C at 550 °C, and the highest absolute temperature reaches 848.7 °C at 750 °C. TiO 2 dopant promotes the decarbonation at lower temperature, and obtains a higher overall conversion (0.506) at 850 °C. Overall, CaCO 3 with TiO 2 dopant is of great significance for future industrial and commercial applications.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Junfang Ding,Liping Li,Ye Wang,Xianzhe Xu,Shaoqing Chen,Xiyang Wang,Huixia Li,Shuaiqiang Zhao,Guangshe Li
Precious metal nanoparticles , widely used as heterogeneous catalysts , are easy to aggregate and deactivate, restricting their applications in many important catalytic fields like preferential CO oxidation (CO-PROX) in H 2 -rich stream. In this work, well dispersed Rh nanoclusters anchored on CaCO 3 @biocarbon derived from waste eggshell (ESMC) were synthesized through a step carbonization and incipient wetness impregnation process. The obtained catalysts exhibited 3D macroporous architecture, which is favorable for exposure of more nucleation sites of precious metal Rh, thus minimizing the aggregation of Rh particles. Furthermore, a thick carbon shell attached to eggshells, with interesting electronic structure and surface chemistry, efficiently transfers electrons between Rh and biocarbon@CaCO 3 support, and enhances the interaction between Rh NPs and support. Both effects synergistically allow Rh/ESMC to equip more active adsorption sites-asymmetric Rh(CO) 2 gem-dicarbonyl, thus greatly promoting the catalytic performance of Rh/ESMC in CO-PROX (operation temperature window: 140–240 °C). The present finding offers an environmentally friendly approach to fabricate well dispersed Rh nanoclusters catalysts, and it can be extended to rationally design other supported metal nanoparticle catalysts.
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高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2025
·
IF 10.9
Mingyu Liu,Sheng Chen,Jianhong Fu,Yunhao Huang,Shuang Liu,Wenqiang Liu
Thermochemical energy storage via the calcium-looping process is a highly promising technology for next-generation concentrated solar power systems. However, the development of efficient and stably operated solar-driven chemical reactors remains a significant challenge. This study provides a comprehensive investigation into the energy storage performance of Al/Fe/Mn co-doped CaCO 3 particles in a kilogram-scale, directly irradiated fluidized-bed reactor, systematically evaluating the spatiotemporal temperature distribution, reaction kinetics, and particle degradation mechanisms under varying fluidizing gas velocities. At low flow rates, a fixed-bed state resulted in severe particle sintering and incomplete reaction. Conversely, under fluidized conditions, particle conversion consistently exceeded 90%. However, while excessively high gas velocities further improved temperature uniformity, the associated convective heat loss limited the reaction rate, leading to a substantial increase in the characteristic reaction time. An optimal flow rate of 18 L/min minimized the calcination time to 18.35 min and yielded a peak solar-to-chemical energy conversion efficiency. Particle degradation was found to be governed by a complex interplay between thermal stress-induced fragmentation (dominant at low flow rates) and mechanical attrition (dominant at high flow rates). Furthermore, significant density-induced particle segregation was observed across all flow rates, with denser, unreacted CaCO 3 particles accumulating at the bottom of the bed. This study provides critical insights into the intricate trade-offs between thermal performance, material integrity, and particle dynamics, which are paramount for the rational design and reliable scale-up of solar thermochemical reactors.
研究领域:
能源材料
·
化学工程
·
太阳能利用
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反应工程
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材料科学
·
热力学
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高影响因子
危险品化学品经营许可证（带存储）