Polymers
·
2024
·Vol. 16
·期 12
·1724
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IF 4.7
Jiaqi Shan,Jia Liu,Jiahui Zhu,Lifei Chen,Ting Xu,Xingfa Ren,Xingzhong Guo
The purpose of this study is to prepare monodisperse silica mesoporous microspheres with narrow pore size distribution to promote their application in the field of liquid chromatography. An improved emulsion method was used to prepare silica mesoporous microspheres, and the rotary evaporation temperature, emulsification speed, dosage of porogen DMF, and dosage of the catalyst NH3·H2O were optimized. Subsequently, these microspheres were respectively treated by alkali–heating, calcination, and sieving. The D50(particle size at the cumulative particle size distribution percentage of 50%) of as–prepared silica mesoporous microspheres is 26.3 μm, and the D90/D10(the ratio of particle size at a cumulative particle size distribution percentage of 90% to a cumulative particle size distribution percentage of 10%) is 1.94. The resultant silica mesoporous microspheres have distinctive pore structures, with a pore volume of more than 1.0 cm3/g, an average pore size of 11.35 nm, and a median pore size of 13.4 nm. The silica mesoporous microspheres with a large particle size, uniform particle size distribution, large average pore size and pore volume, and narrow mesopore size distribution can basically meet the requirements of preparative liquid chromatographic columns.
研究领域:
材料科学
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化学工程
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分析化学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xiangyuan Deng,Yun Liao,Meng Wang,Detao Xiao
Radon (Rn) is an important contributing factor to lung cancer. Activated carbon (AC) is currently the only Rn adsorbent for industrial applications. However, the effect of the key pore size of AC on Rn adsorption remains unclear, and enhancement of the Rn adsorption performance when using AC is still a challenge. In this work, grand canonical Monte Carlo (GCMC) simulations were performed to simulate the Rn adsorption ability of AC with different pore sizes. The adsorption selectivity of AC with pore sizes from 0.42 nm to 0.60 nm for Rn in the atmospheric environment was much greater than that for nitrogen and oxygen. The Rn adsorption performance was also investigated using KOH-modified activated carbon (KAC) with different pore sizes experimentally prepared using high-temperature roasting. The results showed that when the pore volume of KAC was significantly increased to approximately 0.55 nm, the Rn adsorption performance was obviously improved. Its adsorption coefficient reached 6.50 ± 0.11 m 3 kg −1 , which was 46.7 % higher than that of AC. After heating and regeneration in air, the Rn adsorption performance of KAC was basically unchanged. Combined with the comparative analysis using theoretical and experimental results, the relationship between the Rn adsorption performance of KAC and the pore volume at 0.55 nm is determined, and the accuracy of the GCMC calculation results was substantiated. This research provides a theoretical basis and an experimental method for improving the Rn adsorption performance of AC.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
DESALINATION
·
2024
·
IF 8.3
Fan-xin Kong,Shi-yuan Zhang,Ding-wen Zhang,Ping Xia,Jin-fu Chen
Construction of covalent organic frameworks (COF) membranes on the polymeric substrate was challenging by interfacial polymerization (IP) process. In this study, COF-LZU1 membranes were fabricated by IP on the preheated PSf substrates to investigate the influence of substrate properties (i.e., pore size and porosity) on the COF-LZU1 layer formation. The substrates with tunable pore size (18.61 to 14.53 nm) and porosity (2.05 % to 0.42 %) could be obtained with the pretreating temperature of 20 °C to 50 °C. Preheated substrate altered monomer storage and diffusion, leading to the variations in crosslinking degree (14.89 % to 87.63 %) and observed thickness (142.9–575.9 nm). The preheated substrates endowed better growth conditions by inhibiting the COF-LZU1 intrusion into the substrates, and optimal COF 40°C membrane had water flux of 6.57 L m −2 h −1 , and Na 2 SO 4 rejection ratio of 90.9 %. The rejection ratio of pharmaceuticals by COF-LZU1 membranes was low due to adsorption. Correlation analysis showed that the C N bond content was unfavorable for absorption ( P < 0.05), and the increase of crosslinking and crystallinity of the COF-LZU1 layer will be beneficial to boost the pharmaceutical rejection. This work provided a facile method and valuable insight for the COF-LZU1 membrane fabrication to enhance desalination and pharmaceutical removal.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2024
·Vol. 99
·期 12
·2693-2702
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IF 2.8
Yandong Lu,Jiaxu Ning,Yue Zong,Fu Ding,Gaige Liu,Ruijun Zhang
BACKGROUND Tailored design of high-performance nanofiltration membranes is desirable. The physicochemical properties of the organic phaseare essential for the preparation of nanofiltration membranes. Therefore, byfine-tuning the organic phase, it is possible to achieve nanofiltrationmembranes with enhanced performance. RESULTS In this work, oleic acid, a naturally extracted fatty acid, wasintroduced into three different organic solvents (n-heptane, n-octane andisopar G) to construct special oil phases for interfacial polymerization. Testingresults showed that proper dosage of oleic acid addition can effectivelydecrease the nanofiltration membrane pore size and enhance the salt rejectionregardless of the solvent type. Taking n-octane as example, 5% oleic acidaddition in it can decrease the mean pore size from 0.500 nm to 0.341 nm and improve the MgSO 4 rejection from 52.4% to 95.5%. Further characterizationindicated that the introduction of oleic acid into organic solvent cansignificantly reduce the interfacial tension and promote the diffusion of piperazinefrom aqueous phase to the oil phase. In addition, oleic acid could react with piperazineand produce some white particles that could be embed into the polyamide layer, thus altering the surface morphology. CONCLUSION In this work, a novel modified thin film composite nanofiltration membrane was prepared by a simple and controllable oleic acid assisted interfacial polymerization strategy, which exhibits good water permeability, solute selectivity and antifouling property. Without changing the existing process, our strategy opens up a simple, environmentally friendly and operable route for the synthesis of thin film composite nanofiltration membranes. © 2024 Society of Chemical Industry (SCI).
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2019
·Vol. 27
·期 1
·95-105
·
IF 1.947
Xu Xiang,Zeng Yanning,Yu Caili,Zhang Faai
A series of mesoporous SBA-15 with various pore diameter (8, 15, 22 and 27 nm) were synthesized and used as “microreactor”. Reversible addition–fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) was conducted in the channels of SBA-15 using azodiisobutyronitrile (AIBN) as initiator, ethyl xanthate ethyl propionate as chain transfer agent. The obtained PMMA/SBA-15 composites and neat PMMAs from composites were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption and desorption, Fourier transform infrared spectroscopy, thermogravimetry analysis, differential scanning calorimetry, hydrogen nuclear magnetic resonance. Results showed that compared with PMMA from conventional RAFT polymerization, PMMAs obtained from internal SBA-15 featured with narrower molecule weight distribution (1.34–1.55) and higher thermal stability due to confinement effects. With the increment of pore size of SBA-15, the molecular weight and glass transition temperature (T g ) of PMMA obtained from internal SBA-15 were distinctly improved whereas isotacticity of the PMMA decreased. The properties of the PMMA were managed with controllable RAFT polymerization by regulation the pore size of SBA-15.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jiguang Huang,Haiping Chen,Tian Zhou,Run Qi,Heng Zhang
Coal fly ash (CFA) is a promising substitute material in ceramic membrane fabrication to address the high membrane cost issue. However, supports prepared with CFA usually have wide pore size distributions , leading to difficulties in fabricating separation layers. This study focused on overcoming the selectivity-permeability trade-off of membranes based on the CFA support. Five different sizes of alumina powders were adopted to optimize the particle size for separation layer preparation. The membrane prepared using the powder with mean particle size of 1.11 μm under 1150 °C sintering had the best comprehensive performance. The mean pore size was 161 nm and the permeability was 879.71 L/(m 2 ∙h∙bar). Membranes with smaller coating particles had defects because of the particle penetration while membranes with larger particles showed little pore size difference with the support. This work offers opportunities to broaden the application of low-cost CFA membranes.
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2021
·
IF 6.165
Summaira Saghir,Zhenggang Xiao
Ag@ZIF-67 was successfully prepared by using a facile and fast method at room temperature and characterized by a variety of techniques. Results indicate that prepared Ag@ZIF-67 contains a very beautiful morphology with a great active specific surface area than solo ZIF-67. The prepared Ag@ZIF-67 contains a greater pore size, which is 1.564 nm with increased functional sites. The adsorption performance of Ag@ZIF-67 was further studied with the removal of Minocycline (MC) and methyl orange (MO) from polluted water. Various adsorption parameters, such as contact time, adsorbent dosage, pH, and initial concentrations of MC and MO, were optimized. The kinetics parameters of the adsorption process were determined by applying the pseudo first-order kinetic model (PFO) and pseudo second-order (PSO) kinetic model. In the case of MC, adsorption isotherm data matched well with Freundlich as compared to Langmuir and Temkin model. While in the case of MO, adsorption isotherm data followed the Langmuir model as compared to the Freundlich and Temkin model. Ag@ZIF-67 was found to be an efficient adsorbent for the adsorption of MC and MO, having 938.4 mg/g and 994.6 mg/g adsorption capacity, which is higher than reported adsorbents.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Ziqiang Wang,Zechuan Dai,Hongjie Yu,Hugang Zhang,Wenjing Tian,You Xu,Xiaonian Li,Liang Wang,Hongjing Wang
Electrochemical ammonia synthesis is considered as an alternative sustainable method to the traditional Haber–Bosch process because of the reduced energy consumption and mild operation conditions. The key is to design efficient electrocatalysts for facile adsorption and activation of nitrogen. Herein, a nanoporous Pd film with a tunable pore size has been in situ grown on Ni foam (nPd/NF) via a micelle-assisted replacement method using NF as a reductant and substrate, where polystyrene-b-poly(ethylene oxide) and 1,3,5-triisopropylbenzene serve as a pore-forming agent and a swelling agent, respectively. Combining the continuous large nanoporous structure and self-supported properties, the obtained nPd/NF exhibits excellent catalytic performance for ammonia synthesis with a high NH3 yield of 18.27 μg h–1 mgcat–1 and a faradaic efficiency of 10.36% in 0.1 M Na2SO4. This work provides a fascinating route for the rational design of self-supported porous noble metals with a tunable pore size for effective electrosynthesis of ammonia.
研究领域:
材料科学
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电化学
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催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Bo Chen,Qing-Pan Du,Zhi-Jun Diao,Hong Yuan,Jia-Meng He,Yi-Qing Xie,Xiao-Ran Wang,Yu Wang
Hydrogenation upgrading is an effective technique that lowers the oxygen content of bio-oil with the aim of improving its quality. In order to fabricate a series of Ru-based catalysts for the hydrodeoxygenation of bio-oil, several all-silica supports with different pore sizes are synthesized and modified with Al and Cs in this work. The physical morphology and electronic structure of the catalysts are characterized using multiple techniques including X-ray diffraction, in-situ pyridine adsorption infrared spectroscopy, in-situ diffuse reflectance Fourier transform infrared spectroscopy , Raman spectroscopy , CO 2 temperature-programmed desorption, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy , X-ray photoelectron spectroscopy and N 2 physical adsorption-desorption testing. Phenol , guaiacol , anisole and o-cresol are selected as model compounds to investigate the hydrodeoxygenation reactivity of the catalysts. The results reveal that there is a strong linear correlation between the pore size of the catalysts and the rates of the hydrogenation and hydrodeoxygenation of phenol. Importantly, both the oxygen vacancy density and relative content of Brønsted and Lewis sites (B/L) of the catalysts can be greatly increased by Cs modification, which further linearly promotes the hydrodeoxygenation activity of the catalysts. In addition, the in-situ infrared spectroscopy results show that the catalysts modified by Al and Cs heterolytically cleave H 2 to supply H + for the reaction. This work presents a novel approach for fabricating catalysts employed in the hydrotreatment process of bio-oil.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2019
·
IF 10.159
Xiaoxiao Wang,Lizhu Chen,Zhaogang Teng,Zhi-Fei Wang
Mesoporous thin films have been attracting considerable attention due to their potential application in membrane separation technology. However, how to prepare robust mesoporous silica films on a large scale using simple method still remains a great challenge. In this paper, for the first time, we report a facile and novel approach to fabricate layered mesoporous silica thin membrane using mesoporous organosilica nanosheets (mOSiO2 NSs) as the building block, which are prepared by combining template growth and selective etching. Transmission electron microscopy characterization displays that the resulting mOSiO2 NSs possess a large aspect ratio, a controllable thickness (16–27 nm), and a uniform tunable pore size (4–24 nm) by adjusting the reaction conditions. Owing to the large lateral dimension of the nanosheets, the as-prepared mOSiO2 NSs can be easily stacked into a highly packed and oriented membrane via the vacuum filtration. The results show that the nanofilter device based on such mOSiO2 NSs can successfully separate ovalbumin/cytochrome c (OVA/cyt c) or Ag/Au nanoparticles with different sizes, which provides a new strategy for nanosize separation.
研究领域:
材料科学
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生物学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 89
·56183-56193
·
IF 3.108
Yong Zhang,Bin Yang,Kuiling Li,Deyin Hou,Changwei Zhao,Jun Wang
A novel terpolymer (abbreviated as THV), which is a copolymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride, that possesses advantages of excellent hydrophobicity, mechanical properties, and chemical resistance is an ideal material for membrane distillation. In this study, THV hydrophobic membranes were fabricated by the electrospinning method. Morphology and properties (pore size distribution, liquid entry pressure, porosity, and contact angle) of the THV electrospun membranes with various fabrication conditions (solvent composition, THV concentration, and applied voltage) were systematically studied. Under the optimized condition, the membrane exhibited a good structure, wetting resistance, and surface hydrophobicity. The mean pore size, liquid entry pressure of water (LEPw), and contact angle were 0.79 μm, 118.0 kPa, and 130.7°, respectively. Owing to the advantages of the raw material and fabrication method, the membrane showed excellent mechanical properties and desalination performance. The tensile strength was 5.41 MPa, and the elongation at break was 247.9%, which were 2.47 and 5.61 times higher than those of the poly(vinylidene fluoride) (PVDF) membrane, respectively. Additionally, the membrane distillation flux was 4.42 kg m−2 h−1, which was 1.93 times higher than that of the PVDF counterpart obtained under the same test condition via sweeping gas membrane distillation, and the salt rejection rate was higher than 99.8%.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2025
·
IF 9.4
Tian Zhou,Kaili Xue,Heng Zhang,Haiping Chen,Zhaohao Li
Ceramic membrane has been widely used in many fields. The pore size has an important effect on the separation effect of the membrane. Particle sintering is a mature method for preparing ceramic microfiltration membranes and has the advantages of convenient operation and strong controllability. In this study, the composite ceramic membranes with different pore size distributions were prepared. During the experiment, the influence of preparation conditions on the membrane was investigated, and the influence of inner coating and outer coating on the modification of the pore size was analyzed from the theoretical level. The carbon capture performance of the composite ceramic membrane was also tested. The experimental results show that the content of ZrO 2 has an effect on the structure of the film. When the solid content of the coating liquid is higher than 5 wt% and less than 20 wt%, and the sintering temperature is higher than 900 °C and less than 1300 °C, the formed film is complete without defects. Compared with the outer coating, the inner coating of the composite ceramic membrane has better applicability. In the carbon capture test, the CO 2 absorption efficiency can reach more than 90 %.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）