CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Huizhen Zheng,Meng Gao,Ying Ren,Ruyun Lou,Hongguo Xie,Weiting Yu,Xiudong Liu,Xiaojun Ma
A pH-responsive carrier based on an ethylenediaminetetraacetic-calcium-alginate (EDTA-Ca-Alg) system was developed by controlling the release of Ca 2+ . The system remained in the solution state at neutral pH since EDTA completely chelated the Ca 2+ . In contrast, a hydrogel immediately formed when the pH was below 4.0, which triggered the in situ release of Ca 2+ from the EDTA-Ca compound and led to alginate-Ca binding. Taking advantage of the pH sensitivity, we prepared hydrogel microspheres with uniform size to entrap Lactobacillus rhamnosus ATCC 53103 through emulsification. In an acidic environment, the hydrogel structure remained compact with negligible pores to protect L. rhamnosus ATCC 53103. However, in a neutral intestinal environment, the hydrogel structure gradually disassembled because of the Ca 2+ release from the hydrogel, which caused cell release. Therefore, a pH-responsive carrier was developed for the protection and the controlled release of cells in gastrointestinal tract, thus providing potential for oral delivery of probiotics.
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 10
·45940
·
IF 1.86
Mei Wang,Jianchun Jiang,Jianling Xia,Shouhai Li,Mei Li
Phosphate ester groups containing ricinoleic acid-based Ca/Zn (LPPRA-Ca and LPPRA-Zn) stabilizer was successfully synthesized from ricinoleic acid (RA) and used as thermal stabilizers for poly(vinyl chloride) (PVC). These thermal stabilizers were characterized by Fourier transform infrared spectrometry, 1 H nuclear magnetic resonance, and inductively-coupled plasma atomic emission spectroscopy. The effects of LPPRA-Ca/LPPRA-Zn, CaSt 2 /ZnSt 2 , and other stabilizers on the thermal stability of PVC were studied through Congo Red test, discoloration tests, thermogravimetric analysis (TGA), TGA–infrared, and TGA–mass spectrometry. The thermal stability tests show that LPPRA-Ca/LPPRA-Zn displays the best initial color stability and long-term thermal stability for PVC. The superior performance is attributed to the synergistic effect of LPPRA-Ca and LPPRA-Zn. Moreover, a lower Zinc content of LPPRA-Zn in PVC helps to decrease the “zipper dehydrochlorination” of the product, which contributes to a better initial thermal stability. Except for the better stabilization performance, LPPRA-Ca/LPPRA-Zn also displays better plasticization performance for PVC compared with other stabilizers. A possible stabilizing mechanism of PVC/LPPRA-Ca/LPPRA-Zn system was presented. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45940.
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DOI
高影响因子
GREEN CHEMISTRY
·
2017
·Vol. 19
·期 21
·5103-5113
·
IF 9.125
Ying Duan,Min Zheng,Dongmi Li,Dongsheng Deng,Lu-Fang Ma,Yanliang Yang
The catalytic conversion of HMF to 2-hydroxy-3-methyl-2-cyclopenten-1-one (MCP), which is a valuable edible essence that has traditionally been obtained from adipic acid, was achieved with an isolated yield of 58%. This procedure comprised two steps: the hydrogenation of 5-hydroxymethylfurfural (HMF) to 1-hydroxy-2,5-hexanedione (HHD) in water on Pd/Nb2O5 catalysts and then the isomerization of HHD to MCP in the presence of a base. The Nb2O5 supports, which were acidic, were characterized by FTIR, XRD and NH3-TPD. The supported Pd/Nb2O5 catalysts, in which Pd was highly dispersed, were synthesized employing cyclohexene as a reductant and were characterized by XRD, TEM, ICP-AES, XPS, EDX and CO pulse chemisorption. The high conversion of HMF was attributed to the high dispersion of Pd, and the acidity of the supports led to high selectivity for HHD. The conversion of HHD to MCP was an intramolecular aldol condensation reaction, and the protonic solvent favored this reaction. Ca–Al was proved to be an effective solid base for the conversion of HHD to MCP in water.
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高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2015
·
IF 1.865
Kuibao Zhang,Guanjun Wen,Dan Yin,Haibin Zhang
Synroc is recognized as the second generation waste form for the immobilization of high-level radioactive waste (HLW). Zirconolite-rich (CaZrTi 2 O 7 ) Synroc minerals were attempted by self-propagating high-temperature synthesis (SHS) using Fe 2 O 3 , CrO 3 , Ca(NO 3 ) 2 as the oxidants and Ti as the reductant . All designed reactions were ignited and sustained using Ca(NO 3 ) 2 as the oxidant, and zirconolite-rich ceramic matrices were successfully prepared with pyrochlore (Ca 2 Ti 2 O 6 ), perovskite (CaTiO 3 ) and rutile (TiO 2 ) as the minor phases. The sample CN-4, which was designed using Ca(NO 3 ) 2 as the oxidant with TiO 2 /Ti ratio of 7:9, was readily solidified with density of 4.62 g/cm 3 and Vickers hardness of 1052 HV. CeO 2 was successfully stabilized by the CN-4 sample with resultant phase constituent of 2M-CaZrTi 2 O 7 and CaTiO 3 .
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·Vol. 35
·期 48
·2507563
·
IF 19
Ke Su,Lefu Mei,Zunqi Liu,Xin Pan,Pengfei Shuai,Jiyang Xie,Bin Ma,Qingfeng Guo,Cunjian Lin,Mingxing Chen,Zhijian Peng,Libing Liao,Wanbiao Hu,Guocheng Lv
Balancing sensitivity and detection range in dynamic pressure monitoring materials remains challenging, with commercial ruby (Al 2 O 3 :Cr 3+ ) sensors limited by strong crystal fields, restricting performance under extreme conditions. Here, an innovative strategy utilizing an ordered-to-disordered structural conversion in Cr 3+ doped Ca(Mg,Sc)(Al,Si)O 6 phosphors is introduced. This approach achieves a remarkable blueshift sensitivity of 15.08 nm GPa −1 –2.8 times higher than ordered structures and 41 times higher than commercial sensors while maintaining a broad detection range up to 7.5 GPa. Moreover, enhanced structural rigidity notably improves luminescence intensity and thermal stability. The findings establish a robust paradigm for designing high-performance optical pressure sensors, significantly addressing the traditional trade-off between sensitivity and detection range, showing promising applications in geological exploration and aerospace fields.
研究领域:
材料科学
·
光学传感器
·
高压物理
·
发光材料
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DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Yilun Shui,Huiyu Liu,Rui Shan,Min Hao,Chengyu Li,Jun Zhang,Haoran Yuan
The present study proposes a promising strategy for selective pyrolysis of waste tire rubber particles into high-value limonene under the dual action of chemical pretreatments and basic Ca x Mg 1-x Al oxides. The experimental results demonstrate that chemical pretreatments of rubber particles significantly enhance limonene selectivity in pyrolysis products while effectively suppressing the generation of sulfur-containing compounds. Among the various pretreatments, the rubber particles pretreated with 1 wt.% sulfuric acid exhibits optimal performance, which achieves a relative limonene content as high as 35%. The introduction of Ca 0.3 Mg 0.7 Al substantially promotes the selective production of limonene that gives a maximum relative content of 46% in pyrolysis oils. Kinetic analysis confirms that the application of as-prepared Ca 0.3 Mg 0.7 Al greatly lowered the average activation energy from 245.8 kJ/mol to 217.5 kJ/mol for waste tire rubber particles pyrolysis. Moreover, the plausible reaction pathway for waste tire rubber particles pyrolysis under the action of chemical pretreatments and composite metal oxides was proposed. This study, through experiments under ideal laboratory conditions, clarifies the core mechanism of the synergistic regulation of limonene selectivity by chemical pretreatments and basic Ca x Mg 1-x Al oxides, and provides basic research support and technical development directions for the subsequent targeted conversion of industrial-scale waste tire rubber into high-value limonene-rich pyrolysis oils.
研究领域:
环境科学
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材料化学
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能源工程
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绿色化学
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资源循环利用
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热解技术
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催化化学
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Jiajin Li,Minglei Lu,Yuxin Ge,Weiwei Lu,Zidi Liu,Hongde Xu,Yu Zhang,Zhihui Li,Zhuoyu Zheng,Pengxiang Gao,Qian Zhang,Tiejun Wang
Aqueous-phase reforming of methanol (APRM) is an important method for H 2 production, widely used in energy fields like polymer electrolyte membrane fuel cells (PEMFCs). However, traditional noble metal catalysts , being expensive and vulnerable to CO poisoning, restrict their practical application. Therefore, developing robust non-noble metal catalysts for efficient and sustainable H 2 production with low CO levels in APRM at low temperatures is highly significant. In this study, a novel approach was employed to synthesize carbon-encapsulated Cu catalyst via controlled pyrolysis , leading to Cu@CA-Val catalyst with excellent low-temperature catalytic activity. The optimal Cu@CA-Val-300 catalyst exhibited a high hydrogen production rate of 0.2–27.0 μmolH 2 /g cat /s over a wide temperature of 135–180 °C (base-free), surpassing the most Cu-based and Pt-based catalysts. The Cu@CA-Val-300 catalyst exhibited exceptional hydrothermal stability during continuous operation in a fixed reactor for 200 h. Efficient H 2 production was attributed to good wettability , enabling the diffusion of CH 3 OH and H 2 O molecules into Cu + /Cu 0 sites for activation, with CO being suppressed and transformed through the formate formation.
研究领域:
能源化学
·
催化材料科学
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Chenxiao Wang,Kui Liu,Yinghao Wu,Guangjun Zhang,Xuelian Li,Jiaxin Wu,Ruili Sun,Ting Chen,Lang Xu,Shaorong Wang
A-site doping with Ca 2+ , Sr 2+ for the cobalt-free BaFeO 3-δ -based cathode materials for proton-conducting ceramic fuel cells (PCFCs) is studied. The composite Ba 0·8 Ca 0·2 FeO 3-δ (BCF0.2)-BaZr 0.1 Ce 0·7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb) and Ba 0·8 Sr 0·2 FeO 3-δ (BSF0.2)-BZCYYb electrode show polarization resistance (R p ) of 0.156 Ω cm 2 and 0.308 Ω cm 2 at 700 °C, respectively. It is found that the Ca or Sr doping not only benefits oxygen vacancy formation and ion migration but also optimizes the surface oxygen reduction reaction (ORR) process. The density functional theory (DFT) calculations show that the Gibbs energies of *OOH and *OH intermediates are decreased, indicating an enhanced surface ORR. The PCFC with BCF0.2-BZCYYb composite cathode achieves the maximum power density of 299.75 mW cm −2 at 700 °C and shows good stability at 650 °C for 65 h under a constant voltage of 0.75 V. These findings suggest that the BCF0.2-BZCYYb has the potential to serve as cobalt-free cathode materials for PCFCs.
研究领域:
材料科学
·
能源科学
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DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2025
·
IF 4.6
Pengfei Tian,Yunan Shen,Yuzhe Hua,Zilong Chen,Zhifan Chen,Qingjie Guo,Hongjing Tian
Calcium lignosulfonate, an important natural anionic surfactant widely used in chemical, agricultural and construction applications, was employed to enhance the desulfurization performance of Ca(OH) 2 by adjusting its crystal growth at the atomic level. In the digestion of CaO, calcium lignosulfonate was selectively adsorbed onto the 101 surface of Ca(OH) 2 crystal by the interaction between the sulfonic acid group of calcium lignosulfonate and Ca(OH) 2 surface. The specific adsorption was proved to inhibit the growth of the 101 crystal surface owing to the steric hindrance and electronic interactions. DFT calculations show that the adsorption energy is −1.70 eV, and the change in free energy is negative, indicating spontaneous adsorption. By XRD and SEM characterization results and DFT simulation results, while boost the Ostwald ripening of the 001 surface to form the ultrathin nanosheets with a thickness of 16–21 nm. PDOS simulation results testified that the transferring of lone pair electrons from 2p orbital to the empty 3d-orbitals of calcium and the formation of Ca-O bond because of 0.08 Ha blue shift and broadening of the 2p-orbitals of oxygen. Additionally, the calcium lignosulfonate (CLS) modified Ca(OH) 2 exhibited the increase of BET surface area by 62 % from 30.09 m 2 /g to 48.76 m 2 /g and developed a mesoporous structure with the pore volume of 0.248 cm 3 /g. Consequently, the sulfur capacity of Ca(OH) 2 –15.62 mg/g in comparison to pristine Ca(OH) 2 without CLS, while the penetration times for desulfurization experiments increased from 3300 s to 7600 s.
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高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Kun Li,Luxin Liang,Peng Du,Zeyun Cai,Tao Xiang,Hiroyasu Kanetaka,Hong Wu,Guoqiang Xie
Magnesium (Mg) alloys can be regarded as the most promising biodegradable implant materials for orthopedic and stent applications due to their good biocompatibility and low Young's modulus which is near to that of natural bone. However, its applicability is hindered because it exhibits a high corrosion rate in the physiological environments. In this work, we fabricated Mg 66 Zn 30 Ca 4 /Fe bulk metallic glass composites via spark plasma sintering (SPS). We studied the influence of different contents of Fe on the properties of the composites. The results indicated that Fe was uniformly distributed on the surface of Mg 66 Zn 30 Ca 4 metallic glass (MG) as a second phase, which led to an improvement in the corrosion resistance and mechanical strength. The standard potential of Mg 66 Zn 30 Ca 4 /Fe bulk metallic glass (BMG) composites increased as compared to Mg 66 Zn 30 Ca 4 , while their mechanical strength improved from 355 MPa to 616 MPa. Furthermore, cytotoxicity was investigated via the CCK-8 assay and calcein-AM staining, which revealed that the extraction mediums diluted 6 times (EM × 6) of the Mg 66 Zn 30 Ca 4 and Mg 66 Zn 30 Ca 4 /Fe did not cause cell toxicity on day 3 and 5, while the EM × 6 of the Mg 66 Zn 30 Ca 4 showed cytotoxicity on day 1, 3 and 5. Thus, Mg 66 Zn 30 Ca 4 /Fe BMG composites exhibit significant potential for fabricating implants with good mechanical strength and corrosion resistance.
研究领域:
材料科学
·
生物医学工程
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DOI
高影响因子
Biomaterials Science
·
2019
·Vol. 7
·期 9
·3614-3626
·
IF 5.251
Yihong Gong,Yiling Zhang,Zhinan Cao,Feng Ye,Zefeng Lin,Yan Li
Injectable scaffolds have attracted much attention because of their minimum surgical invasiveness. However, limited osteogenic induction property and low mechanical properties hampered their application in bone tissue engineering. CaCO3 microspheres, which possess osteoinductivity, rough surfaces and specific binding sites for BMP-2, were first fabricated; after BMP-2 uploading, microspheres were further entrapped in fibrin-glue hydrogel. CaCO3 microspheres were co-functionalized with casein and heparin. To obtain a high encapsulation of heparin and thus BMP-2 uploading, along with controlled release and simultaneous maintenance of the presence of vaterite which had osteogenic induction property, fabrication parameters were optimized and microspheres were characterized using XRD, FITR and SEM. The formed CaCO3 had a microsphere morphology of ∼1 μm. Both vaterite and calcite phases were present and the relative amount of calcite phase increased with the amount of heparin. Sample 25 mM_4-1Hep with the highest loading amount of heparin was selected as carrier for BMP-2 and BMP-2 loaded CaCO3 microspheres were further entrapped in fibrin-glue hydrogel (FC-B). For the as-prepared composite hydrogel, mechanical properties were characterized and the presence of CaCO3 significantly elevated the tensile strength; controlled release of BMP-2 was sustained until day 21. Based on ALP activity, alizarin red staining and RT-PCR, in vitro osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was found to be significantly enhanced under induction of FC-B. Rabbit tibia bone defect model was applied to evaluate its in vivo performance. After implantation for 4 weeks, presence of composite hydrogel was observed in defects. After 8 weeks, bone defects of FC-B group were nearly completely healed. Using the fact that autologous scaffolds can be derived based on fibrin-glue hydrogel, the well-designed BMP-2 loaded fibrin-glue composite hydrogel demonstrated good potential in bone tissue engineering.
研究领域:
组织工程
·
生物材料
·
骨再生
·
药物递送系统
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yunlei Zhao,Youyou Li,Bo Jin,Zhiwu Liang
As a powerful process intensification strategy, chemical looping shows a promising future to achieve an integrated CO 2 capture and utilization for reducing CO 2 emissions and energy-cost penalties. Herein, a bifunctional Ca-Fe-Mg material derived from layered double hydroxide (LDH) was synthesized and used in chemical looping reforming process for integrated CO 2 capture and utilization. Reactivity tests and detailed characterization techniques are performed to examine and explain the performance of this material. 900 °C is determined as a suitable reforming temperature, since more syngas production is obtained (2.5 times of at 800 °C). The presence of Ca induces a synergetic interaction between Ca and Fe to implement an enhanced performance of syngas contents and stable H 2 /CO ratio. The activity deactivation of the material derives from the phase transition of Ca 2 Fe 2 O 5 to MgFe 2 O 4 , crystal size variation and particle agglomeration. Compared to a reference coprecipitated material, LDH derived Ca-Fe-Mg material shows an enhanced syngas production, due to its highly dispersion of CO 2 sorption and reforming active sites. This work provides a new route to rationally design bifunctional material for integrated CO 2 capture and utilization.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）