ACS Biomaterials Science & Engineering
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2019
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IF 4.511
Yanting Liu,Yuanyuan Yang,Yajing Shen
The tubularlike three-dimensional tissue scaffold is an important architecture in biomedical engineering, but its construction remains a big challenge for existing techniques. This work reports the polysaccharide-biomaterial-based tubular microcapsule, which was fabricated by integrating a co-axial flow microfluidic chip and a polyelectrolyte complex technique. First, we fabricate the densely packed coiled calcium alginate hydrogel microfibers as the building block by a co-axial microfluid chip. Then, the densely packed coiled microfibers were coated with a multilayer membrane through layer-by-layer adsorption of alginate and chitosan. After that, the microfibers with an alginate–chitosan–alginate membrane were expanded and transformed into a tubular microcapsule structure by liquefaction. The tubular microcapsule exhibits a selectively permeable property of different-molecular-weight FITC-dextran/bovine serum albumin compared with original calcium alginate microfibers. Moreover, the tubular microcapsule with a liquefied lumen and a thin membrane allows the sustainable release of encapsulants under the alkaline environment. Our research paves an alternative way of manufacturing artificial biological tube architectures having potential applications for transporting and delivering drugs.
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EUROPEAN POLYMER JOURNAL
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2019
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IF 3.621
Jian Hao,Huiqing Wei,Chunxiang Lu,Yaodong Liu
Poly(acrylonitrile-co-itaconic acid) (PAI) is the most widely used precursor for making high performance carbon fiber. In this study, we synthesized PAI with various contents of itaconic acid (IA) in the range of 0 to 22 mol%. The addition of IA not only changes acrylonitrile (AN) segment length distribution, but also initiate AN cyclization at a lower temperature. The effects of PAI sequence distribution and initiation mechanisms on PAN cyclization were systematically studied by differential scanning calorimetry, nuclear magnetic resonance, Fourier transform infrared spectroscopy and thermogravimetry. These results show how the AN sequence length and the carboxyl groups in IA affect the cyclization reaction, the formed ladder structures, and carbon yields.
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EUROPEAN POLYMER JOURNAL
·
2019
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IF 3.621
Weilong Chen,Kun Wu,Zhencai Qu,Mangeng Lu
It has been known that phonon mean free path along polymer chains is much larger than in transverse directions because weak interaction between polymer chains leads to chain distortion and entanglement. In order to improve intensity of intermolecular interaction, a series of co-polyesters (CPE) containing different content of offset π-π stacking structure in side chains were synthesized by means of polycondensation and transesterification in this work. WAXD patterns unfolded diffraction peak at 2θ of 27.6°, standing for structure of offset π-π stacking. On enlarging intensity of offset π-π stacking interaction, specific heat capacity of CPE increased from 1.140 Jg −1 K −1 to 1.410 Jg −1 K −1 and thermal diffusivity rose from 0.194mm 2 s −1 to 0.245mm 2 s −1 . As a result, CPE sample exhibited excellent thermal conductivity (TC) of 0.381 Wm −1 K −1 , which is around twice that of traditional thermoplastics. Hence offset π-π stacking interaction could strengthen capacity of heat absorption and thermal conduction at the same time, which might be a good candidate for enhancing thermal conductivity of intrinsic polymers. Furthermore, strong π-π interaction in side chains could maintain modulus when temperature is over glass temperature. And the Young modulus grew from 0.14 GPa to 0.44 GPa with the augment of offset π-π stacking structure.
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NUCLEAR TECHNOLOGY
·
2022
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IF 1.667
Yanhui Wang,Qiao Jiang,Yexin Yang,Jianfeng Cheng,Chenyang Bao,Yuelong Pan,Yu Liu,Gang Yang,Yangchun Leng,Xianguo Tuo
The alteration of the morphology of bentonite, a key barrier to isolating high-level radioactive waste in deep geological repositories under long-term interaction with groundwater, was studied. Bentonite colloids were prepared from Gaomiaozi bentonite, and its various properties were analyzed by various characterization methods. The effects of various factors on the adsorption of Cs(I) and Co(II) on bentonite colloids were investigated by batch static adsorption experiments. The results showed that the colloids were mainly composed of montmorillonite and were lamellar in shape, with a zeta potential of −enton mV and an average size of approximately 209.10 nm. The adsorption of Cs(I) and Co(II) by the colloids was a rapid process, and 31.78 and 88.24 mg/g, respectively, were adsorbed at equilibrium. Pseudo-second-order kinetic fitting showed that chemisorption plays a dominant role and acid-base interactions affect adsorption by influencing the stability of colloids and the chemical form of simulated nuclides. This work can be helpful for evaluating the safety of waste repositories.
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DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 44
·17081-17088
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IF 4.569
Wenyuan Wang,Kai Zhang,Tao Xu,Yagang Yao
Nowadays, the goal of carbon peaking and carbon neutrality has become a global consensus, and electrochemical CO2 reduction to provide high-value power fuel is one of the major technical approaches attracting significant research interests and application prospects. However, the inevitable hydrogen evolution reaction in water-based electrolyte systems crowds out the reactive sites of active metals, causing a low CO2 conversion efficiency. In this work, Zn nanosheets were prepared via electrodeposition on the surface of carbon paper and then modified with polytetrafluoroethylene (PTFE) to tune the wetting angle of the electrolyte. A CO faradaic efficiency of 90.2% was achieved for Zn NS-8% PTFE (contact angle: 136.8°) at the electrolytic voltage of −1.0 V vs. RHE along with an overall current density of −7.9 mA cm−2. Experimental results and molecular dynamics simulation revealed that PTFE weakened the aggregation of H2O molecules and was more beneficial for capturing and adsorbing CO2 molecules near the electrode surface. The active sites of hydrogen production were transformed into the reaction center for electrocatalytic CO2 reduction due to the hydrophobicity of the electrode, and the accumulation of the local CO2 concentration accelerated the kinetic activity for electrochemical conversion (CO2 to CO). This strategy of tuning the local environment offers an alternative approach for effective electrode manufacturing in liquid electrolytes.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
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IF 7.139
Shuai Sun,Tianci Wang,Kejiang Qian,Hao Zhang,Kaifeng Ji,Zijian Shi,Mingyu Chen,Cui Zhang,Shuangxi Liu
High-efficiency water splitting catalysts are competitive in energy conversion and clean energy production. Herein, a bifunctional water splitting catalyst CoNiP with cation vacancy defects (CoNiP–V) is constructed through defect engineering. The results show that abundant cation vacancy defects in CoNiP–V are bifunctional active centers in the process of water electrolysis , which enhance the activity of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). In 1.0 mol L −1 potassium hydroxide, CoNiP–V requires a pretty low overpotential of 58 mV to reach a geometrical current density of 10 mA cm −2 for HER. To deliver a current density of 100 mA cm −2 , only 137 mV and 340 mV of overpotential are needed for HER and OER, respectively. Moreover, the cell with CoNiP–V as both cathode and anode exhibits good stability, which only needs 1.61 V to achieve a current density of 100 mA cm −2 , and the cell voltage barely rises 10% after 100 h’ test under 100 mA cm −2 . Therefore, CoNiP–V is promising for the development of efficient water splitting catalysts.
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ACS Catalysis
·
2026
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IF 13.6
Liu Meng-Nan,He Zhen-Hong,Chen Zhuo,Wang Sen-Wang,Ruan Miao,Luo Yanping,Wang Kuan,Wang Weitao,Wang Huan,Liu Zhao-Tie
Direct hydrogenation of CO 2 to liquid hydrocarbons (C 5+ ) at low temperature is a highly desirable but challenging transformation, as conventional catalysts typically operate at high temperatures via indirect pathways by producing and using a CO intermediate. In this work, we report an inverse ZrO 2 /Co catalyst that enables direct CO 2 hydrogenation to C 5+ hydrocarbons at a low temperature of 200 ° C. Under optimal conditions, the catalyst achieves a high CO 2 hydrogenation activity of 26.0 mmol CO2 ·g Co –1 ·h –1 with 58.9 C-mol % selectivity toward C 5+ liquid hydrocarbons and negligible CO formation. The inverse architecture of ZrO 2 /Co, wherein ZrO 2 nanoislands are dispersed over metallic Co 0 particles, concurrently not only enhances CO 2 adsorption and suppresses H 2 adsorption but also delivers a surface C/H ratio approximately 31 times higher than that of pristine Co 0 , thereby promoting chain growth. In situ DRIFTS reveals that the inverse catalyst generates abundant oxygen-containing intermediates (HCOO–, HCO 3 –, CH 3 O–, and CH 3 COO–), which are subsequently hydrogenated to CH x for chain growth over Co 0 sites. This work not only provides a low-temperature catalyst for direct CO 2 -to-C 5+ conversion but also establishes inverse oxide/metal interfaces as a general platform for tuning C–C bond coupling in CO 2 hydrogenation.
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International Journal of Applied Ceramic Technology
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2023
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IF 2.1
Xiao-Chun Deng,Xiao-Dong Kang,Guo-Hua Zhang
(HfNbTaZrTiMo)C-Co high entropy carbide cermet was fabricated by conventional vacuum sintering. The effect of WC addition on the mechanical properties of cermets was also investigated. For cermets without WC addition, with the extension of sintering time, the hardness of cermets first rose and then fell, while the fracture toughness showed a decreasing trend. The increase in sintering temperature led to a decline in hardness and an enhancement of fracture toughness. The (HfNbTaZrTiMo)C-15 wt. % Co cermet sintered at 1450°C for 2 h had the best comprehensive properties, with the hardness and fracture toughness of 16.36 ± 0.17 GPa and 7.19 MPa·m 1/2 , respectively. After adding WC, there was a typical black core (undissolved (HfNbTaZrTiMo)C phase)-gray rim (seven-component (HfNbTaZrTiMoW)C solid solutions) structure in the cermets. Meanwhile, Mo diffused into WC to form (Mo, W)C solid solutions. The formations of (HfTaZrNbMoTiW)C and (Mo, W)C solid solutions resulted in an improvement in hardness. In addition, since the addition of WC enhanced the wettability between carbides phase and Co phase, the comprehensive properties of cermets were improved. The hardness and fracture toughness of the (HfNbTaZrTiMo)C-42.5 wt. % WC-15 wt.% Co cermet sintered at 1450°C for 2 h were 17.42 ± 0.06 GPa and 8.22 MPa·m 1/2 , respectively.
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JOURNAL OF HAZARDOUS MATERIALS
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2023
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IF 13.6
Shenjun Wang,Xiaonan Tan,Yuhao Wu,Jun Zhang,Zhiyuan Tian,Jiahai Ma
Rapid isolation of microplastics is the prerequisite for correct and in-depth understanding of their environmental impacts and human health threats. And Fenton’s reagent (Fe/H 2 O 2 system, FHS) has been proven to be a viable way to isolate microplastics from wastewater, but it is limited because of harsh reaction conditions, long reaction time and low efficiency. Herein, it's proven that the Fenton-like system, which is using Cobalt (II) salts to decompose potassium peroxymonosulfate (Co/PMS system, CPS) with generation of 1 O 2 , can offer shorter time (within 30 min) in complex sample isolation. The experimental results showed that the isolation time of micro/nanoplastics from pollutants with CPS in only 30 min, while it was at least more than 5 h with FHS. Via a serious of experiments of comparison and characterization between FHS and CPS, whether from the point of view of reaction time or isolation effect , CPS is superior to FHS. On this basis, we validate the applicability of this system (CPS) in different reaction conditions (concentration, pH), different sizes (from microns to nanometers) and types of plastic (PS, PA, PE, PP, PVC). In addition, the CPS can also preserve the integrity of the plastic itself and reduce the impact on the quality of samples evidenced by a variety of characterization of physicochemical structure like UV–vis, TEM, AFM , FTIR and XPS. CPS is proved to be faster, higher, stronger for enhancing the isolation of micro/nanoplastics from complex matrix. In a word, this study provides a promising solution for the efficient isolation of microplastics from wastewater without causing additional harm to the plastics.
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JOURNAL OF MEMBRANE SCIENCE
·
2023
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IF 9.5
Xiangqiong Wang,Quan Wang,Jie Li,Naixin Wang,Quan-Fu An
Pervaporation is an effective technique to improve the conversion of acetic acid in the esterification reaction through in situ removing the product water. In this study, a co-solvent assisted contra-diffusion strategy was used to prepare covalent organic framework (COF) pervaporation membrane on the polyacrylonitrile porous substrate. Fatty alcohol was used as the co-solvent in the organic phase to tune the reaction region. Subsequently, the COFs were formed in the sub-surface of the substrate to form a nanoconfined composite membrane , which was then modified by polyvinyl alcohol through spinning coating. The obtained COF composite membranes were used to in situ remove water during the esterification from acetic acid and ethanol. Consequently, compared with the esterification without pervaporation, the conversion of acetic acid was enhanced from 74% to 90%, which exhibited an excellent intensification for the esterification reaction.
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Journal of the American Chemical Society
·
2023
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IF 15
Zhi-Zheng Wu,Xiao-Long Zhang,Peng-Peng Yang,Zhuang-Zhuang Niu,Fei-Yue Gao,Yu-Cai Zhang,Li-Ping Chi,Shu-Ping Sun,Jing-Wen DuanMu,Pu-Gan Lu,Ye-Cheng Li,Min-Rui Gao
Carbon–carbon coupling electrochemistry on a conventional copper (Cu) catalyst still undergoes low selectivity among many different multicarbon (C2+) chemicals, posing a grand challenge to achieve a single C2+ product. Here, we demonstrate a laser irradiation synthesis of a gerhardtite mineral, Cu2(OH)3NO3, as a catalyst precursor to make a Cu catalyst with abundant stacking faults under reducing conditions. Such structural perturbation modulates electronic microenvironments of Cu, leading to improved d-electron back-donation to the antibonding orbital of *CO intermediates and thus strengthening *CO adsorption. With increased *CO coverage on the defect-rich Cu, we report an acetate selectivity of 56 ± 2% (compared to 31 ± 1% for conventional Cu) and a partial current density of 222 ± 7 mA per square centimeter in CO electroreduction. When run at 400 mA per square centimeter for 40 h in a flow reactor, this catalyst produces 68.3 mmol of acetate throughout. This work highlights the value of a Cu-containing mineral phase in accessing suitable structures for improved selectivity to a single desired C2+ product.
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FUEL
·
2023
·
IF 7.4
Yuxin Sun,Yunshuo Wu,Yarong Bai,Xuanhao Wu,Haiqiang Wang,Zhongbiao Wu
Iridium nanocatalysts are ideal candidates for the selective catalytic reduction of NO x by CO (CO-SCR) in excess oxygen. Here, a high-performance Ir nanocatalyst supported on natural halloysite nanotubes (HNTs) was applied for the CO-SCR. The HNTs loaded with only 0.5 wt% Ir achieved 78 % NO x conversion at 250 °C in the presence of 5 % O 2 , which was the highest among catalysts with varied Ir loadings or reduction temperatures. It also possessed an excellent SO 2 and H 2 O tolerance during longevity tests. An interesting SO 2 -enhanced CO-SCR long-term stability was observed, which was ascribed to the inhibitory effects of SO 2 on the side reaction between CO and O 2 . The loading amount and the reduction temperature could modulate the size of Ir nanoparticles and the percent of Ir 0 , which were two key factors determining the CO-SCR activity. DRIFTS characterizations and DFT calculations coherently revealed the favorable adsorption sites of CO (top) and NO (hcp) on Ir nanoparticles. The Ir atoms served as a charge transfer bridge from the C atom of CO to the N atom of NO, leading to the enhanced breakage of N-O bonds. This work provides Ir/HNT as a promising CO-SCR material with high performance and robustness to tackle NO x pollution.
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