The diffusion limitation owing to the long and narrow pore structure in traditional ZSM-5 zeolite could restrain the adsorptive desulfurization performance towards thiophene sulfur compounds from fuels. Herein, ZSM-5 zeolite nanocrystals were successfully fabricated using steam-assisted gel crystallization strategy to control the size of zeolite particles within 70 ∼ 160 nm. Compared to traditional micron ZSM-5, ZSM-5 zeolite nanocrystals could effectively reduce the diffusion pathway, enlarge the specific surface area, and increase exposure of adsorption sites, which could enhance the desulfurization performance. ZSM-5 nanocrystals with a mole ratio SiO 2 /Al 2 O 3 of 200 exhibited a satisfactory desulfurization efficiency, and the breakthrough capacity attained 0.0509 mmol S/g adsorbent. After ZSM-5 nanocrystals were ion-exchanged with NH 4 + and Ag + , both mesoporous characteristics and the Lewis acid (L-acid) sites were enhanced, which promoted the adsorption desulfurization performance. Furthermore, nanocrystalline ZSM-5 and Ag/ZSM-5 also exhibited acceptable regeneration performance. This study is expected to provide an effective strategy and a facile method to prepare nanocrystalline ZSM-5 based adsorbents for the development of efficient desulfurization materials.
Lei Wu,Kun Zhang,Qiuyan Ye,Yingjie Lv,Jiaqiao Li,Xiaoyan Guo,Yongnan Chen,Yiming Chen
Titanium alloys exhibit excellent mechanical properties, good corrosion resistance and biocompatibility, making they widely used in medical field. Nevertheless, their practical application is frequently constrained by bacterial infection and corrosion issues in physiological environments. To overcome these challenges, this study proposes a novel multifunctional strategy involving the incorporation of Ag + -loaded ZSM-5 zeolites into a micro-arc oxidated (MAO) coating on the surface of titanium alloy to fabricate Ag/ZSM-5@MAO-Ti composite coating. The microstructure, mechanical properties, and functional characteristics of the coating were systematically characterized. Analysis confirmed that Ag/ZSM-5 were evenly dispersed within the MAO coating while preserving the crystal structure intact. By leveraging the mechanical interlocking effect, the particles were securely retained within the micropores of the MAO layer after in-situ hydrothermal secondary growth. The composite coating exhibited exceptional adhesion to the titanium alloy substrate, with an average bond strength of 64 N. Owing to the inherent hydrophilicity of zeolites, the composite coating demonstrated significantly enhanced hydrophilicity with a contact angle of 12.9±0.7°. Antimicrobial tests results revealed that the coating achieved an inhibition rate of more than 99.99% against Escherichia coli (E. coli), and the sustained release of Ag⁺ ensures long-term antimicrobial efficacy. Furthermore, the composite coating displayed superior corrosion resistance in phosphate buffer solution (PBS). In summary, the Ag/ZSM-5 modified MAO coating substantially enhances the antimicrobial properties and corrosion resistance of titanium alloy, offering a promising strategy for the development of advanced medical devices.
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