Coatings
·
2024
·Vol. 14
·期 3
·297
·
IF 2.9
Haiping Zhang,Jixing Cui,Jiayuan Yang,Hui Yan,Xinping Zhu,Yuanyuan Shao,Hui Zhang,Jesse Zhu
Environmentally friendly powder coatings which have the advantages of being VOC-free, low-cost, and high-efficiency with a high recovery rate have been attracting increasing research attention. The introduction of antibacterial agents into the powder coatings endows them with a capacity to kill bacteria and viruses on the surface of objects; additionally, this enables them to inhibit the indirect transmission of pathogenic microorganisms. Silver, possessing broad-spectrum, strong, and stable antibacterial properties, is considered to be a promising antibacterial material for use in coating applications. Carrier materials for active silver play an important role in its activity and stability. However, there is a lack of systematic studies on the effects of different types of carriers in such coating systems, especially in green powder coating systems. In this paper, we investigated two types of carriers for active silver agents: zeolite, i.e., Linde type A (LTA) zeolite and Y-type zeolite; clay-based materials, i.e., montmorillonite and vermiculite. All the agents showed high antibacterial activity, with antibacterial rates of over 99% as compared to commercial agents. Among the four agents, the Ag-LTA zeolite antimicrobial agent showed a reduction rate of over 99.99%; additionally, it maintained a reduction rate of 99% after seven washing cycles. Thus, this agent was demonstrated to have the highest effectiveness and high durability; these features can be attributed to the high silver content and small particle size. The LTA zeolite also provides a protective effect for silver ions, protecting them from reduction, due to the restriction of elemental silver formation within the confined interior space of the α-cage structure. The Y-type zeolite antimicrobial agent exhibited a slightly lower antimicrobial performance due to its higher silicon-to-aluminum ratio and its lower cation exchange capacity. Comparatively, antimicrobial agents utilizing clay-based carriers have lower cation exchange capacity, resulting in poorer antimicrobial effectiveness than zeolite carriers. In addition, silver loaded on clay-based materials is prone to detach from the carrier and undergo a reduction reaction, making the coating yellowish in color. This study first provides information on the roles of different types of carriers in powder coating systems; then, this information guides the selection of carriers for active silver for the development of efficient antimicrobial agents and coatings.
研究领域:
材料科学
·
微生物学
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DOI
高影响因子
INORGANIC CHEMISTRY
·
2026
·Vol. 65
·期 35
·20464-20471
·
IF 4.6
Sun Ling,Gao Zhanyong,Li Huimin,Xu Xinyi,Zhao Di,Li Huanrong
Silver nanoclusters (AgNCs) with
exceptional luminescence
suffer
from an aggregation-induced loss of their unique quantum confinement
effects. LTA zeolites are ideal hosts for stabilizing AgNCs, yet most
reported water-responsive AgNC@LTA systems only exhibit binary luminescence
switching, restricting high-resolution multilevel environmental monitoring.
Herein, we construct a Mg 2+ -regulated AgNC@LTA system via
sequential ion exchange and thermal treatment. The as-prepared Ag-LTA(Na/Mg)
achieves continuous three-state luminescence switching with yellow
emission in dehydration, red in slight hydration, and green in full
hydration. Mechanistic studies reveal that Mg 2+ isolates
AgNCs, blocks framework-to-cluster charge transfer, and stabilizes
the intermediate excited state. The luminescence was confirmed as
phosphorescence. This material realizes a naked-eye-resolvable color
transition over 0%–60% relative humidity with excellent reversibility,
breaking the binary limitation and offering an avenue for high-precision
visual humidity sensors.
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Fangge Chen,Yanhong Li,Aisheng Huang
Because of the increase of industrial wastewater containing insoluble oil and oil discharged accidents, oil/water separation has turned out an exceedingly crucial and urgent issue in environmental protection. Therefore, it is terribly significant to develop a simple and effective technology for oil/water separation. Membrane separation has been well known as a promising method to remove oils from water due to its energy-efficiency and cost-effectiveness. In the present work, we report the synthesis of a hydrophobic zeolite FAU named F-FAU through a simple and effective post-synthetic modification. Firstly, a thin zeolite FAU layer is grown on the 3-aminopropyltriethoxysilane (APTES) modified stainless steel net (SSN) to form SSN supported FAU (SSN@FAU) coating. And then, a hydrophobic SSN@F-FAU coating is prepared through post modification of SSN@FAU coating with perfluorooctyltriethoxysilane (POTS). After POTS modification, the water contact angle (CA) of the SSN@FAU coating increases from 15° to 132° for SSN@F-FAU coating, while both morphology and structure of the SSN@FAU coating keep unchangeable. Attributing to the high hydrophobicity of the F-FAU coating, the SSN@F-FAU coating shows a wonderful oil/water separation performance, with oil/water separation efficiency of above 98.8 % and oil flux of up 50,000 L m −2 h -1 . After 50 cycles successive separation of hexane/water mixture, the separation efficiency of the SSN@F-FAU coating keeps constant (over 99.1 %), showing potential application for oil/water separation in industries. Further, hydrophobic SSN@F-LTA coating can be consistently prepared through post modification of SSN@LTA coating with POTS, and also shows a high oil/water separation performance, with oil/water separation efficiency above 99.0 % and oil flux over 40,000 L m −2 h -1 , confirming the universality of the preparation strategy.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2021
·Vol. 27
·期 37
·9654-9660
·
IF 5.236
Lichao Wang,Lian Xu,Bingmei Su,Wei Lin,Xinqi Xu,Juan Lin
Graphical CASTing call : A semi-rational combinatorial active-site saturation test (CAST) was performed to improve the C β stereoselectivity of threonine aldolase. MD simulations suggested that the Y314R variant could interact with 4-methylsulfonyl benzaldehyde through hydrogen bonding to control the direction of entry of substrate, this increased the de value from 58 to 81 %. l -Threonine aldolase from Actinocorallia herbida ( Ah LTA) is an ideal catalyst for producing l - threo -4-methylsulfonylphenylserine [(2 S ,3 R )- 1 b ], a key chiral precursor for florfenicol and thiamphenicol. The moderate C β stereoselectivity is the main obstacle to the industrial application of Ah LTA. To address this issue, a combinatorial active-site saturation test (CAST) together with sequence conservatism analysis was applied to engineer the Ah LTA toward improved C β stereoselectivity. The optical mutant Y314R could asymmetrically synthesize l - threo -4-methylsulfonylphenylserine with 81 % diastereomeric excess ( de ), which is 23 % higher than wild-type Ah LTA. Molecular dynamic (MD) simulations revealed that the mechanism for the improvement in C β stereoselectivity of Y314R is due to the acylamino group of residues Arg314 controlling the orientation of substrate 4-methylsulfonyl benzaldehyde ( 1 a ) in the active pocket by directed interaction with the methylsulfonyl group; this leads to asymmetric synthesis of l - threo -4-methylsulfonylphenylserine. The success in this study demonstrates that direct control of substrates in an active pocket is an attract strategy to address the C β stereoselectivity problem of LTA and contribute to the industrial application of LTA.
研究领域:
生物催化
·
酶工程
·
分子生物学
·
化学合成
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Dingcheng Liang,Fengqin Yu,Qiang Xie,Qingping Chen,Yuan Liu,Yuhua Zheng,Keping Zhu,Zhijun Zhang,Jun Liu,Xiao Zhu,Jinchang Liu,Zihan Zhu
Activated carbon (AC) is a broad-spectrum adsorbent but is flammable and has low adsorption capacities for polar and/or high-boiling volatile organic compounds (VOCs), while zeolites exhibit high thermal stability but poor adsorption of macromolecular and nonpolar VOCs. In this study, zeolite/AC composites were synthesized with the aim of obtaining broad-spectrum, efficient, and safe adsorbents for VOCs. Dimethyldiallylammonium chloride (DDA)-modified AC was used as a carrier for an in situ hydrothermal reaction enabling assembly with zeolites due to electrostatic attraction. Interface models were constructed for their phases, which revealed the binding force and simulated the binding process. The adsorption and flame resistance of the composites were evaluated. The results showed that DDA effectively modified AC to give it a long-lasting positive charge in solutions. High-silicon and pure-silicon zeolites exhibited low negative charges or were even neutral; it was difficult to combine with the modified AC via electrostatic attractions. Instead, LTA zeolites with high aluminum contents and negative charges were used, and the seed-induction method was used. Ethanol and ultrasonic dispersion were used to prevent agglomeration of the seeds and modified AC powder, so they were self-assembled electrostatically. Moreover, the crystallization time was extended and composites with high zeolite loadings were successfully prepared. According to the model calculation, the binding energy between the zeolite and AC before and after the DDA modification were 324.97 and 1076.46 kcal mol–1, respectively, and the distance between them was shortened by 2.7 Å after DDA treatment. As a result, AC and zeolite combined more closely and exhibited a stronger binding energy. The adsorption capacity for highly polar dichloromethane was improved by zeolite loading on the AC, and the bed penetration time was doubled. However, impregnation with inorganic sodium enhanced the reactivities of the organic components in the composite, and the ignition point was slightly reduced. Furthermore, the electrostatic self-assembly method can expand to prepare the LTA zeolite/columnar AC composite from shaped AC, greatly improving its application prospects.
研究领域:
环境科学
·
材料科学
·
化学工程
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DOI
高影响因子
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