FUEL
·
2021
·
IF 6.609
Hao Shen,Zihao Yang,Xiaochen Li,Ying Peng,Meiqin Lin,Juan Zhang,Zhaoxia Dong
Hydraulic fracturing and CO 2 flooding are extensively used in low-permeability reservoirs to enhance oil recovery (EOR). However, due to the serious heterogeneity of the formation, CO 2 is prone to break through the oil-bearing zone prematurely, which leads to the decrease of the swept volume. Conventional blocking agents have some defects such as difficult injection, poor stability and weak sealing strength. Therefore, it is critical to developing a new type of channeling blocking agent for low-permeability fractured reservoirs. In this study, ten kinds of chemicals with tertiary amino groups are filtered for the most effective CO 2 -responsive agent, which turns out to be N, N-Dimethyl erucamide tertiary amine (DMETA). Subsequently, rheological properties, response performance, and microstructure of the optimum agent are researched systematically through rheological experiments, CO 2 -response processes and Cryo-TEM. The results show that the viscosity of the DMETA solution can increase to nearly 605,700 mPa·s by self-assembly into wormlike micelles (WLMs). And it can be reversibly circulated between low viscosity and high viscosity by alternately introducing and removing CO 2 , which endows it with the ability to healing its viscoelasticity under an environment full of CO 2 . A new method based on optical microrheology is proposed to study the viscoelastic properties of WLMs under no external force. The experiments prove that the network structure is not stable after formation, but remains in a continuous process of separation and reconstruction as “a living polymer.” Furthermore, the plugging performance and EOR capacity are evaluated using fractured tight cores. The experiments demonstrate that the optimum agent can effectively restrain gas channeling and enhance recovery factor by 21.7%. We expect our work can provide insights for the synthesis of CO 2 -responsive WLMs and guidance for retarding gas channeling during CO 2 flooding in low permeability reservoirs.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2021
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IF 6.165
Yanling Wang,Yongfei Li,Qian Wang,Lei Liang,Longhao Tang,Chuanbao Zhang,Jincheng Lan,Lingtao Meng,Baoyang Jiang
In gas condensate reservoirs, liquid condensation near the wellbore region can break gas well deliverability when the pressure drops lower than dew point . Gas-wetting alteration is one of the potential approaches to overcome the difficulty. However, gas production remains restricted because the wettability of the core surface can only be altered from original liquid-wetting to neutral gas-wetting by traditional methods. Herein, fluorine-modified nanocrystalline cellulose is developed to achieve super gas-wetting alteration, increasing the contact angles of brine and decane on core surface from 22° and 0 o to 153° and 142°, respectively. This product not only reduces the surface free energy from 68.41 mN/m to 0.35 mN/m but also increases the surface roughness from 68.23 nm to 154.51 nm. The capillary tube and imbibition experiments further confirm that the wettability of the core surface has been altered from strong liquid-wetting to super gas-wetting. This result indicates that the liquid is easier to peel from the core surface to improve the ability of transportation and distribution. Besides, after the super gas-wetting alteration, the required pressure for displacement is reduced and the core permeability is restored dramatically. Meanwhile, it has been proved that fluorine-modified cellulose is more suitable for unconventional low permeability reservoirs. This work also reveals the mechanism of super gas-wetting alteration in detail, which will expand the better application of the material in more oilfields and other mining engineering developments.
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高影响因子
Particuology
·
2021
·
IF 3.067
Miao Song,Yafeng Yang,Hongdan Zhao,Maoqiao Xiang,Qingshan Zhu,Jibin Jia,Chaoquan Hu,Fen Yue
TiCl 2 is a promising precursor for producing metallic titanium alloys and titanium-based ceramics. However, the effective synthesis of high-quality TiCl 2 powder remains challenging. Herein, a fluidized bed reactor (FBR) providing a high gas–solid contact area was employed to synthesize TiCl 2 powder using a reliable TiCl 4 –Ti reaction system. Optimal reaction conditions (600 °C and 120 min) were determined for the proposed Ti–TiCl 4 system by kinetic investigation. A dense Ti layer was regenerated upon the original surface of the Ti powder as a result of TiCl 2 disproportionation at high temperature (above 700 °C), which impeded infiltration by gaseous TiCl 4 . The particle size of the Ti reducing agent played a vital role in the production of TiCl 2 powder. A mean particle size of 24.5 μm was confirmed to be the most feasible option based on the optimal chlorinated depth (17 μm).
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高影响因子
Biomaterials Science
·
2021
·Vol. 9
·期 6
·2313-2321
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IF 6.843
Yuchu He,Cong Cong,Shuxian Zhao,Zhuo Li,Desong Wang,Jianmin Gu,Lanxiang Liu,Dawei Gao
The gaseous microenvironment (GME) of tumors is rapidly becoming a new concern for nanotechnology-mediated oncotherapy. Here, we constructed a tumor/near-infrared (NIR) light-responsive nanoplatform to generate O2 and NO for remodeling the GME of tumors and phototherapy. The biocompatible and pyrolytic polydopamine was used to load indocyanine green, NONOate, and MnO2 NPs as a nanoenzyme (PINM). Then, HA was modified on the PINM to form the final nanoplatform (PINMH). PINMH can target tumors favorably due to the modification of HA. Under the NIR light irradiation, PINM converts the light and O2 to hyperpyrexia (58.5 °C) and cytotoxic 1O2. MnO2 NPs catalyze the H2O2 overexpressed in tumors to O2, which increases the amount of 1O2. Moreover, NONOate decomposes to NO (100 μM) under hyperpyrexia, thus leading to the gas therapy. The results verified that the responsive nanoplatform with precise gaseous regulation and phototherapy exhibited a superior anti-tumor effect (V/V0 = 1.2) and biosafety. In addition, PINMH can be tracked in real-time via magnetic resonance imaging. In this study, an intelligent nano-platform integrated with diagnosis and treatment was developed, which used the phototherapy technology to reshape GME and achieve good anti-tumor effects, aiming to provide an innovative and reasonable strategy for the development of tumor treatment.
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PubMed
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
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2021
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IF 3.739
Han Wang,Shulan Wang,Jingqiao Zhang,Han Wang,Hui Li,Yi Zhao
Several mesostructured cellular foams (MCFs) were prepared and modified for NO adsorption. TMB, NH 4 F and n -heptane were used as swelling agents, and APTES was used as the modified agent. The morphological structure, chemical composition, thermostability were tested to study the effects of the preparation process on the characterizations of materials. NO adsorption ability of the materials were studied and discussed. NH 4 F and n -heptane had better pore swelling effects compared to TMB, however adding TMB together with NH 4 F and n -heptane could not enlarge the pore structure further. The MCFs materials could keep steady below 800 °C, but after grafting APTES on the surface of the materials, the thermogravimetric curve of materials began to decrease at 300 °C. The materials using NH 4 F and n -heptane as the swelling agents, and modified by APTES had better NO adsorption ability, and the selectivity of the materials were decided by the molecular polarity of the adsorbates. After the modification, the hydrophobic effect of the samples could increase because of the alkyl groups in APTES. The adsorption capacity of the materials could keep steady for ten times without the coexisting component, H 2 O, CO 2 and SO 2 all had negative effects on the regeneration of the materials.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Guoxiong Deng,Jiangzhou Luo,Xiangyun Liu,Xibo Zhang,Yilei Wang,Xueping Zong,Song Xue
In this work, a series of symmetrical “H-shaped” tetramine monomers bearing different amounts of side groups and linking units were designed and synthesized via a simple one-step electrophilic substitution reaction of aromatic dialdehyde and aniline. Then, these new designed tetramine monomers using as the crosslinking center were reacted with 6FDA to prepare the network polyimide (PI) membranes. Due to the robust 3D crosslinked structures, all the network PI membranes possessed high rigidity ( T g = 322 ∼ 337 °C), excellent thermal stability ( T d , 5% =425 ∼ 471 °C), and superior mechanical performance with the tensile strengths ranging from 107.2 to123.0 MPa and elongations of 4.2–5.4%, while the stone-like solubility in common solvents. Interestingly, during the period of tridimensional polycondensation reaction of these designed network PIs, a broad operating flexibility without the risk of gelation was observed, which is beneficial to their actual productions. Furthermore, gas transport results proved that changing the amounts of CH 3 side groups at the ortho -positions of the aniline ring and extending their framework’s linking units in the crosslinking center provide viable ways to fine-tune the fractional free volume (FFV) within the polymers, which in turn tailor their gas transport properties efficiently. Specifically, the optimum membrane termed as 6FDA-OHTA showed a huge increment about ∼ 340% for CO 2 permeability accompanying with only ∼ 5.6% reduction for CO 2 /N 2 ideal selectivity in comparison with those of the original 6FDA-PTA membrane. We hope this study can open a new avenue to the rational design of network PI membranes to meet various separation needs, especially from the view of crosslinking center structure variation.
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高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 33
·期 1
·280-289
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IF 3.665
Peng Kong,Jingqian Deng,Zhongjie Du,Wei Zou,Chen Zhang
A comb-like polymer containing crystallized alkyl side chains and the intermolecular hydrogen bonds between the linking groups was fabricated by grafting long-chain fatty amine onto poly(styrene-co-acrylic acid) n (P(S-AA) n , wherein “n” denoted AA feed ratio). The chemical structures and crystallization behaviors of the comb-like polymer P(S-AA) n -g(p) (wherein “p” denoted the number of side-chain carbon atoms) were analyzed by Fourier transform infrared, gel permeation chromatography, X-ray photoelectron spectroscopy, and X-ray diffractometer, differential scanning calorimetry, atomic force microscopy, respectively. It was found that the lamellar morphology could be generated by controlling the grafting density and side chain length of P(S-AA) n -g(p). Moreover, it was identified that the hydrogen bonds between amide groups could enhance the crystallinity and then adjust the interlamellar spacing of lamellar phase. As a result, P(S-AA) 70 -g(18) with the highest degree of crystallinity and closely packed lamellar morphology showed a good gas-barrier performance, and the nitrogen permeability reached 1.78 × 10 −14 cm 3 ·cm/cm 2 ·s·Pa. Furthermore, the permeation switch of the obtained comb-like polymer could reach 500 times traversing the melting point.
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高影响因子
MEASUREMENT SCIENCE and TECHNOLOGY
·
2021
·Vol. 32
·期 9
·095114
·
IF 2.046
Qianchun Zhang,Yan Wang,Qin Zhou,Yafei Chen,Yuguo Zheng,Shan Tang,Yuxian Zhao,Li Jiang
Nonmetallic nanocatalysts have demonstrated powerful potential in cataluminescence (CTL) sensing fields. In this study, an original method for the fabrication of a CTL gas sensor was developed to detect acetylacetone based on nanosized hexagonal boron nitride (h-BN). The luminescence characteristics and optimum operating temperature, wavelength, and carrier gas flow rate parameters for the h-BN sensor were studied in detail. Compared with other common gases (such as cyclohexanone, acetaldehyde, and acetone), the fabricated sensor demonstrated a high selectivity and sensitivity toward acetylacetone. This was verified by density functional theory calculations, which were consistent with the experimental results. The CTL intensity and concentration of acetylacetone had a linear relationship in the range of 0.050–20 μg ml−1 (r = 0.9989) with a low detection limit of 16 ng ml−1 (S/N = 3). The developed sensor was applied to analyze spiked samples, and satisfactory recoveries for acetylacetone of 82.2%–118% were obtained with excellent reproducibility (2.8%–11%). These results indicated that the system has excellent sensing properties including a high selectivity, sensitivity, and stability, proving its broad application prospects for detecting acetylacetone.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2021
·
IF 7.46
Yuting Wang,Xiaoqiong Fu,Tianqi Wang,Feng Li,Dan Li,Ying Yang,Xiangting Dong
In this work, a Cu 2 ZnSnS 4 (CZTS)-based gas sensor incorporated by polyoxometalate(POMs) electron acceptor were synthesized by hydrothermal method . For the first time we investigated on the application of CZTS in NO 2 sensor and the influence of POMs incorporating on gas sensing performances of CZTS sensor. As a result, the gas sensing response could be remarkably improved to 6.12 times by incorporating POMs compared with pure CZTS. This is mainly attributed to introducing POMs into CZTS could reduce electron-hole recombination and facilitate electrons transfer. The research results exhibit the highest gas sensing response of CZTS-based gas sensor up to now. This research reveals a new idea for developing high-performance gas sensors based on CZTS by introducing POMs.
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高影响因子
MICROCHEMICAL JOURNAL
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2021
·
IF 4.821
Ying Wang,Hong-Xing Li,Sheng-Ming Xie,Bang-Jin Wang,Jun-Hui Zhang,Li-Ming Yuan
Porous organic cages (POCs) are a new class of advanced porous molecular materials, which are self-assembled from discrete, shape-persistent, cage-like molecules through relatively weak intermolecular forces. POCs have recently received extensive interest in diverse fields due to their noteworthy features of good solubility, unique pore structure, high stability, tunable pore size and volume, and so on. In this study, we report a [3 + 6] prismatic homochiral POC (NC1-R) as the stationary phase for preparing a capillary gas chromatographic (GC) column by a static coating method. Various types of mixtures have been well separated on the coated column, involving n -alkanes, n -alcohols, alkylbenzenes, positional isomers, structural isomers, and cis- / trans -isomers. Most importantly, the column also exhibits excellent chiral resolution capability for racemates. Twenty-three racemates, including alcohols, epoxides, esters, lactones, ethers, amino acid derivatives, amines, and sulfoxides, have been well resolved on the column. Among these racemates, about half (11 of the 23) could not be resolved on a commercial β-DEX 120 column (per- O -methylated β-cyclodextrin-based column), suggesting the advantageous performance of the present column. Furthermore, the fabricated column shows good reproducibility in terms of the retention times of analytes, with relative standard deviations (RSDs) in the ranges 0.02–0.19 %, 0.12–0.36 %, and 0.41–0.59 % for intra-day ( n = 6), inter-day ( n = 6), and column-to-column ( n = 3), respectively, and good thermal stability at least up to 300 °C. This work demonstrates the good application prospects of NC1-R for GC separations, especially for GC enantioseparations.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yuhang Chen,Yaheng Zhang,Hongwei Zou,Minglei Li,Gang Wang,Min Peng,Jie Zhang,Zhiyong Tang
Difficult handling the solid catalysts remains one of the pain points in the continuous flow photochemistry. In this work, the gas–liquid-solid segmented flow was employed in the photocatalytic production of azo- compounds (azoxybenzene and azobenzene) from nitrobenzene using graphitic carbon nitride (g-C 3 N 4 ) as solid catalyst. Compared with the batch reactor, the photocatalytic reaction rate was greatly improved in the microreactor, and the reaction time was shortened from 180 min of the batch to 7.5 min for near-full conversion of nitrobenzene. The effects of various reaction parameters (temperature, light source power, catalyst content) in the continuous system were examined, and the reaction kinetic was found in first order. The photocatalytic reaction performance was very sensitive to the gas–liquid-solid segmented flow conditions, which needed to be carefully tuned. With the help of high-speed camera and micro particle image velocimetry (µ-PIV) techniques, it was identified that the increasing inert gas fraction resulted in more stable segmented flow with shorter liquid segments, favoring the reaction rate. With a high gas fraction, the intensity of recirculation in the liquid segments was strengthened by the increasing total flow rate, enhancing the local mass transfer, thereby benefiting the photocatalytic reaction. Overall, the continuous microreactor reached 5.6 times higher productivity per volume (26.1 mmol/h*L) of azo- compounds than the batch reactor under the same conditions. The successful photosynthesis of azo- compounds demonstrated the great potential of the presented gas–liquid-solid segmented flow, and the findings of this work provide useful guidance on its future application in other heterogeneously catalyzed reactions.
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高影响因子
Journal of Water Process Engineering
·
2021
·
IF 5.485
Bing Wang,Mingyang Xiong,Bin Shi,Zhuoying Li,Huan Zhang
A carbon-nanotube-nested diatomite adsorbent (CND-composite adsorbent) was successfully prepared and introduced to remove organic contaminants from shale gas flowback water. The CND-composite adsorbent was then characterized using Scanning Electron Microscopy, Brunauer Emmett Teller, Mercury Intrusion Porosimetry and X-ray Diffraction (XRD) analyses. The changes in the organic species present in the shale gas flowback water before and after adsorption were characterized via Gas Chromatography-Mass Spectrometer. The kinetics, isotherms and thermodynamics of the adsorption of organic matter in shale gas flowback water on the CND-composite adsorbent were investigated on the basis of static experiments. The CND-composite adsorbent had hierarchical mesoporous/ macroporous structures. The adsorption experiments indicated that the maximum removal efficiency for total organic carbon was 78.91 %. The adsorption mechanisms mainly involved intermolecular interactions, electrostatic interaction and hydrogen bonds. Results showed that the Freundlich isothermal model and pseudo-second-order model were suitable for the characterization of the adsorption process in this work. The changing values of thermodynamic parameters, including the Gibbs free energy, entropy, and enthalpy, indicated that the adsorption process was spontaneous and endothermic. In addition, the adsorption process was jointly controlled by physical and chemical mechanism. In summary, the CND-composite adsorbent has potential for utilization in the removal of organic pollutants in real wastewater.
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高影响因子
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