GREEN CHEMISTRY
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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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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
CEMENT AND CONCRETE RESEARCH
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2024
·
IF 10.9
Binmeng Chen,Xu Fang,Yuyang Zhao,Zongjin Li
In recycling and reusing construction waste, carbonation of recycled concrete fine (RCF) has been successfully applied to produce value-added products, such as silica nanoparticles, via the breaking of calcium silicate hydrate (C-S-H) structure and condensation of silicate chains. However, the intricacies of carbonation of RCF with varying calcium to silicon (C/S) ratios and their implications on the size of generated silica nanoparticles remain unknown. In this work, we developed an optimized carbonation method at high water to solid ratio to fabricate silica nanoparticles from C-S-H with different C/S ratios. The particle size of silica nanoparticles was found to gradually decrease with the increased C/S ratio of C-S-H. Since as C/S ratio increased, silicate in Q 3 state shifted to Q 1 state and the silicate chain became shorter, shifting from long-range, disordered to short-range, ordered. As the disordered self-seeding growth of long silicate chains derived from C-S-H continued, the Si-O-Si network of silica nanoparticles became chaotic, leaving more unreacted Si-OH on its surface. On the contrary, the short silicate chains displayed higher possibility of condensation, making nanoparticles with a smaller diameter.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2025
·
IF 2.4
Ruiqi Huang,Zhaoyang Lu,Can Xu,Shuaiting Liang,Honglei Yuan,Geshan Zhang,Lihui Jia,Jun Yuan
Background Spent sulfidic caustic (SSC) from petrochemical and other chemical industries usually contains high concentrations of sulfur ion (S 2− ) and caustic soda (NaOH), which requires effective treatment. Here a CoPcSA/CaAl-LDHs catalyst was successfully synthesized by using a facile one-pot approach for loading cobalt phthalocyanine tetrasulfonamide (CoPcSA) on Ca–Al hydrotalcites (CaAl-LDHs). The material characterization included powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. Results The effect of various parameters such as reaction temperature, catalyst dosage and aeration rate on the catalytic activity was investigated and optimized to be 75 °C, 1.5 mmol L −1 and 2.5 L min −1 , respectively. CoPcSA/CaAl-LDHs shows very high catalytic efficiency for S 2− removal: a 95.0% S 2− removal can be achieved at extremely high concentration of S 2− (24 000 mg L −1 ). In addition, the catalyst exhibits high stability and reusability even after 8 cycles of reuse. Conclusion CoPcSA/CaAl-LDHs exhibits outstanding catalytic activity and stability, showing impressive potential in practical application. © 2025 Society of Chemical Industry (SCI).
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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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CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Ruixiang Li,Shu Chen,Beibei Wang,Xiaodan Wang,Xinyu Hu,Sonia Estrade Albiol,Cristian Fabrega Gallego,Hao Shen,Chunhua Luo,Hui Peng,Hechun Lin
Room-temperature gas sensors are crucial for detecting toxic gases and volatile organic compounds (VOCs). Conventional metal oxide semiconductor (MOS)-based sensors, however, often require high-temperature operation and suffer from low sensitivity. Here, we present a one-step mini-mechanochemical synthesis of CuO/M(OH) 2 (M = Mg, Ca) heterostructures that exhibit exceptional room-temperature sensing performance towards triethylamine (Et 3 N). Our results reveal a tenfold enhancement in the sensor response to Et 3 N compared to pristine CuO. This remarkable improvement is attributed to the in-situ formation of oxygen vacancies in CuO induced by the incorporation of M(OH) 2 , as evidenced by X-ray photoelectron spectroscopy (XPS), positron annihilation spectroscopy (PAS), and electron paramagnetic resonance (EPR). Notably, CuO/Mg(OH) 2 demonstrates superior long-term stability, while CuO/Ca(OH) 2 suffers from performance decay due to environmental carbonation. Furthermore, we developed a portable Et₃N analysis device based on the CuO/Mg(OH) 2 sensor, which enables real-time monitoring with Wi-Fi capability and achieves an accuracy within 6 % error across a 1 to 100 ppm detection range. This study not only provides a cost-effective and scalable fabrication method for CuO-based gas sensors but also highlights the potential of CuO/M(OH)₂ in practical applications for environmental monitoring and food safety assessment.
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COMPOSITES PART B-ENGINEERING
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2025
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IF 14.2
Zhengyang Miao,Guangzheng Zhu,Lei Yang,Peng Ding,Fang Jiang
Polymer-based thermally conductive composites have garnered significant attention in recent years due to their critical applications in areas of national strategic importance. Nevertheless, the inherently limited thermal conductivity and mechanical properties of polymers pose challenges to their practical application. Recent research indicates that employing exogenous methods and facilitating molecular-level interactions between fillers and cross-linkers are effective strategies to overcome these limitations. In this study, with the aid of the ionic effect during the sol-gel phase transition of aqueous sodium alginate molecules in the presence of divalent cations and biaxial stretching, combined with the hydrogen bonding between boron nitride nanosheets (BNNS) with excellent thermal conductivity and sodium alginate (SA) molecules, the BNNS-calcium alginate (BNNS/Ca-SA/D) films were constructed by the strategy of gel reconstruction, rehydration, evaporation-assisted self-assembly and biaxial stretching. By designing anisotropic structures with closely aligned interconnected BNNS (Herman orientation parameter as high as 0.865), the BNNS/Ca-SA/D films with a BNNS loading of 40 wt% were characterized by high in-plane thermal conductivity (45.50 W•m −1 •K −1 ) and good mechanical properties. Combined with finite element analysis to simulate the heat transfer process, the “thermo-mechanical” coupled multilevel oriented structure composite films were constructed due to the densification arrangement and the increase of interfacial adhesion during multiple cross-linking processes, and the orientation arrangement of BNNS during the tensile-induced process. The potential of the BNNS/Ca-SA/D films developed in this study for thermal management applications has been demonstrated by the practical application of thermal management devices and the human body. The polymer-based thermally conductive films developed in this paper offer promising applications for thermal management systems in modern power electronics.
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ENERGY
·
2025
·
IF 9.4
Qi Zhou,Liu Wu,Jingyue Wang,Jie Liang
Lignin, with its complex structure and high stability, poses a significant challenge in the directed depolymerization to obtain aromatic-rich bio-oil. To prevent the formation of hard-shelled char resulting from the melting and agglomeration of lignin during pyrolysis, this study proposed a dual strategy combining Ca(OH) 2 pretreatment and Beta zeolite, which demonstrated a synergistic effect through β-O-4 bond cleavage, effectively suppressing lignin condensation while achieving high aromatic selectivity. In this study, the influence of various operational parameters was examined. Key variables including pretreatment procedures, concentration levels, catalyst selection, catalyst-to-raw material ratio, carrier gas velocity, and pyrolysis thermal conditions were analyzed to determine their effects on the critical processes. Pretreatment with 5 wt% Ca(OH) 2 significantly reduced lignin agglomeration during pyrolysis. Using Beta zeolite (1:1 mass ratio) in CFP at 500 °C with 75 mL/min carrier gas flow increased bio-oil yield from 5.0 wt% to 7.5 wt% and enhanced aromatic selectivity from 1.9 area% to 84.9 area%. Using 2-phenoxy-1-phenylethanol (α-OH-PPE) as a model compound, we found Ca(OH) 2 pretreatment and Beta zeolite together enhanced β-O-4 bond cleavage in lignin. This synergistic approach facilitated efficient bond cleavage and showed remarkable effectiveness in aromatic production.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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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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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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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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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
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生物材料
·
骨再生
·
药物递送系统
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高影响因子
危险品化学品经营许可证（带存储）