JOURNAL OF MEMBRANE SCIENCE
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2021
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IF 8.742
Shishi Yang,Huali Tian,Matthew R. Hill,Kaisong Zhang
Oxidized molybdenum disulfide (O–MoS 2 ) as a two-dimensional (2D) functional nanosheets material, has been used to fabricate high separation performance nanofiltration (NF) membranes for water treatment. However, the effect and regulation mechanism of the degree of oxidation on structure and separation performance of O–MoS 2 modified NF membrane has not yet been fully understood. In this work, O–MoS 2 with different oxidation degrees was synthesized by adjusting the oxidation time and KMnO 4 oxidant content via Hummers’ method. The results demonstrated that the O–MoS 2 synthesized under with an oxidation time of 3 h and MoS 2 :KMnO 4 ratio of 1:2 had excellent stability under acidic, neutral and alkaline conditions. The pure water flux increased 2.5 times and the Na 2 SO 4 salt rejection increased to 97.6% with this O–MoS 2 incorporation compared to the control membrane. The influence of different oxidation degrees on the performance of O–MoS 2 is a breakthrough finding of this work to provide a theoretical basis for the application of O–MoS 2 in the field of membrane separations .
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
GREEN CHEMISTRY
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2017
·Vol. 19
·期 15
·3611-3617
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IF 9.125
Meng Li Liu,Lin Yang,Rong Sheng Li,Bin Bin Chen,Hui Liu,Cheng Zhi Huang
Photoluminescent (PL) carbon dots (CDs) as a new type of carbon nanomaterial have attracted increasing attention owing to their fascinating properties. Herein, we develop a facile, energy-efficient, large-scale route to prepare highly PL CDs with a quantum yield of up to 35.3% at room temperature. These PL CDs can be further separated out into green-emissive amorphous carbon nanodots (CNDs) and yellow-emissive crystalline graphene quantum dots (GQDs) through a silica gel column. Both the as-prepared CNDs and GQDs, even when having the same particle-size distribution and chemical groups, have different degrees of surface oxidation. As characterized by X-ray photoelectron spectroscopy (XPS), the yellow-emissive crystalline GQDs have a much higher surface oxidation degree than that of the green-emissive amorphous CNDs. A further finding is that the characteristic emission peaks of the CDs show an obvious red shift from 518 nm to 543 nm with the increase in the surface oxidation degree, which can be attributed to the decrease in their band gap between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO). That is, the difference in band gap is closely related to the oxidation degree of the CDs, rather than the particle size or chemical groups. Moreover, the amorphous CNDs are very easily photobleached under 140 W xenon lamp irradiation as compared to the crystalline GQDs, indicating that the photostability is dependent on the crystalline structure of the CDs, which is beneficial for the top-down design and development of suitable CDs for different application purposes.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
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2018
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IF 3.52
He Ren,Yongbo Lyu,Xinying Li,Shuxiao Zhang,Yusong Ye,Defu Li,Changdao Mu
Consumers demand more alternatives of riskless antibacterial agents to prevent microbial contamination in food industry. Oxidized carbohydrate may be a potential option as new antibacterial agent. However, the relatively weak antibacterial property of oxidized carbohydrate is not satisfactory. In this paper, dialdehyde β-cyclodextrins with different oxidation degree were prepared by periodate oxidation and their antibacterial properties were systematically studied. The results showed that multi-aldehyde groups were successfully introduced into β-cyclodextrin molecules by periodate oxidation. The aqueous solubility and stability of dialdehyde β-cyclodextrins were improved as expected. It is interesting that dialdehyde β-cyclodextrins possessed outstanding antibacterial activity against both Gram-positive and Gram-negative bacteria. The minimal inhibitory concentrations against E. coli, S. aureus and B. subtilis reached 0.63, 1.25 and 0.63 mg/mL, respectively. Moreover, dialdehyde β-cyclodextrins effectively inhibited bacterial growth on the surface of apples. The results demonstrated that oxidized oligosaccharide with multi-aldehyde groups and good dispersibility in aqueous solution possessed satisfactory antibacterial activity, which can be used as new antibacterial agent in food industry.
研究领域:
食品科学
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微生物学
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产品关联
DOI
PubMed
高影响因子
FUEL
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2024
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IF 6.7
Xiujie Quan,Zhixin Lin,Conglin Chen,Tao Ma,Yang Zhang
The inherent properties of hard asphalt binder give it both mechanical and economic benefits, rendering it a naturally advantageous material for preventing permanent deformation at higher temperatures. However, its poor resistance to thermal and fatigue cracking limits its application in the paving industry. This study aimed to improve the low-temperature and fatigue performance of hard asphalt binders by using the newly developed vegetable oil-based sub-epoxidized rapeseed oil (SERO). Two SEROs with epoxidation degree of 49.1% and 98.1% were synthesized through an oxidation reaction, respectively. Subsequently, the microstructural characteristics of SEROs were examined by Fourier transform infrared spectroscopy (FTIR) and Hydrogen nuclear magnetic resonance tests. The anti-oxidative aging properties of SERO modified hard asphalt binders were investigated through the utilization of mass loss and aging index. Additionally, the comprehensive rheological properties of SERO modified hard asphalt binders were explored via dynamic shear rheometer and bending beam rheometer tests. Furthermore, the modification mechanism of SERO on hard asphalt binders was confirmed through the quantitative analysis using the FTIR test. The findings suggested the improvement in anti-volatilization and anti-oxidative aging performance of bio-modified hard asphalt binders, which was positively related to the epoxidation degree of SERO. A notable softening effect of SERO on the hard asphalt binders was observed, which enhanced their resistance to thermal and fatigue cracking at lower and intermediate temperatures. The epoxy groups within SERO engaged in ring-opening reactions, forming a new oxygen bridge bond by combining with the unsaturated double bond presented in the asphalt. Consequently, this process resulted in the formation of cross-linked structures within bio-modified hard asphalt binders, thereby enhancing the elasticity. Notably, this phenomenon was most conspicuous in the SERO-H modified 50# binder. Finally, the environmental and economic assessment of SERO modified hard asphalt binders were conducted by the techno-economic method and the emission factors technique. The data revealed that the production of one ton of SERO modified hard asphalt binders could reduce the production costs by about 30%, energy consumption and CO 2 emissions by around 20% in contrast to styrene–butadiene–styrene block copolymer modified asphalt binders. Hence, the substantial economic and environmental advantages make SERO an attractive bio-renewable additive for sustainable pavements.
研究领域:
土木工程
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材料科学
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环境科学
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产品关联
DOI
高影响因子
CARBON
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2016
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IF 6.198
Wen-Hui Hu,Xiao Shang,Guan-Qun Han,Bin Dong,Yan-Ru Liu,Xiao Li,Yong-Ming Chai,Yun-Qi Liu,Chen-Guang Liu
A simple wet chemical method has been used to prepare MoS x in situ grown on graphene oxide (MoS x /GO) as a highly active and stable electrocatalyst for hydrogen evolution reaction (HER). The role of the oxygen-containing functional group on the surface of GO with different oxidation degrees have been studied for obtaining MoS x /GO with excellent electrochemical activity for HER. The electrochemical measurements show that MoS x /GO using the medium degree of oxidation of GO as matrix exhibits best electrocatalytic activity for HER with a small overpotential of ∼195 mV at the current density of 20 mA cm −2 . A tafel slope of ∼47.7 mV per decade is obtained for MoS x /GO modified electrode. The turnover frequency per active site is calculated. Both the amount of active sites for HER and conductivity of the electrocatalyst have been greatly improved owing to the good dispersion and conductivity provided by GO matrix. Therefore, this work suggested that choosing GO with suitable oxidation degree as support is the key for synthesizing MoS x based electrocatalysts with enhanced HER activity.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2025
·
IF 5.6
Jiewen Mo,Xiaoteng Chen,Jinxing Sun,Haowen Liang,Peng Zhou,Pavel Grinchuk,Jiaming Bai
Silicon carbide ceramics, featuring high-temperature resistance, are important in aerospace and renewable energy fields. With the increasing demand for complex ceramic structures, traditional manufacturing methods are becoming inadequate. Additive manufacturing technology based on vat photopolymerization holds great promise. However, during the additive manufacturing process of silicon carbide ceramics, issues such as light absorption and limited curing depth are faced. These problems impede the effective development of high-solid-loading silicon carbide ceramic slurries. This study systematically probes into the impacts of powder modification, dispersant concentration, and solid loading on the properties of silicon carbide ceramic slurries. Additionally, the oxidation degree of the powder was regulated. A slurry with a 50 vol.% solid loading suitable for vat photopolymerization has been developed, and complex silicon carbide structures have been fabricated. After sintering, the samples exhibit a flexural strength of 235.62 MPa and a density of 2.79 g/cm 3 , thus enhancing the potential for manufacturing complex ceramic components.
研究领域:
材料科学
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增材制造
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陶瓷工程
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
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2024
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IF 3.9
Xiaogeng Hou,Hongbin Hou,Yixiao Wang,Bao Qin,Liang Zhang,Qinggang Wang
The preparation of four types of epoxidized iron-based comb butadiene-isoprene rubber (EBIR) with different epoxidation degrees (4.7%, 6.4%, 10.2%, and 12.3%) was investigated for the first time in this study. The modification involved the use of hydrogen peroxide and formic acid as raw materials for the epoxidation process. Following this, silica/EBIR composites were prepared by mixing EBIR with silica nanoparticles, without the use of a silane coupling agent (SCA). The objective was to investigate the influence of the epoxidation degree on the structure and properties of the resulting silica/EBIR nanocomposites. The results indicated that the introduction of epoxy groups had a positive effect on the interfacial interaction between the rubber and filler, leading to improved dispersion of the silica nanoparticles in the rubber matrix. Consequently, the tensile properties, wet skid resistance, and abrasion resistance of the silica/EBIR composites were found to be superior to those of the un-epoxidized silica/BIR composites. Furthermore, comparing the silica/EBIR-12.3 nanocomposites with silica/BIR-Si69 nanocomposites, it was revealed that silica/EBIR-12.3 showed a 69.4% enhancement in wet skid resistance and an 8.0% reduction in rolling resistance. These findings demonstrate the potential of silica/EBIR composites for high-performance tire tread rubber applications, offering environmental benefits and improved properties. Graphical
研究领域:
材料科学
·
轮胎工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2021
·
IF 6.953
Peng Wang,Zhi-gang Luo,Zhi-gang Xiao,Ahmed S.M. Saleh
Oxidized gellan gum (OGG) hydrogel beads as delivery systems for resveratrol were fabricated by ionic cross-linking with calcium chloride (CaCl 2 ). The degree of oxidation (DO) and CaCl 2 concentration had significant influences on the formation and functional properties of hydrogel beads. The resveratrol encapsulation efficiency (66.43%–79.84%) and loading capacity (4.15%–5.05%) of OGG hydrogel beads were enhanced as DO increased. The hydrogel beads exhibited a uniform spherical shape as observed by scanning electron microscope. Fourier transform infrared spectroscopy analysis confirmed that hydrogen bonds and ionic interaction participated in the formation of hydrogel beads. X-ray diffraction analysis revealed that the physical state of resveratrol was changed from crystalline to amorphous form after encapsulation. Furthermore, the physical stability and antioxidant capacity evaluation demonstrated that the hydrogel bead fabricated with DO80 OGG and CaCl 2 concentration of 1.0 M could provide high protection for resveratrol against degradation by environmental stresses and maintain its antioxidant capacity. The DO and CaCl 2 concentrations could modulate the in-vitro release behaviors of hydrogel beads and obtain a good small intestinal-targeted release of resveratrol at high DO and medium CaCl 2 concentration. These findings suggested that a promising delivery system for encapsulating bioactive ingredients can be fabricated by rational design.
研究领域:
药学
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材料科学
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生物技术
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Jie Hao,Fangxia Wu,Rong Tang,Yuanyuan Sun,Dehua Liu,Zhenqing Zhang
Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1 H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides , and in-source fragmented MS for analysis of oxidized polysaccharides . The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0.
研究领域:
化学
·
材料科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）