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期刊论文 4

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2023 2

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2018 1

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Stavax钢 1

疏水性 1

皮秒激光 1

表面纹理处理 1

高分子聚合物 1

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Benzenesulfonic acid-grafted UIO-66 with improved hydrophobicity as a stable Brønsted acid catalyst

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1389-1398 doi: 10.1007/s11705-022-2285-5

摘要： Hydrothermal and catalytic stability of UIO-66 MOFs with defective structures are critical aspects to be considered in their catalytic applications, especially under the conditions involving water, moisture and/or heat. Here, we report a facile strategy to introduce the macromolecular acid group to UIO-66 to improve the stability of the resulting UIO-66−PhSO3H MOF in aqueous phase catalysis. In detail, UIO-66−PhSO3H was obtained by grafting benzenesulfonic acid on the surface of the pristine UIO-66 to introduce the hydrophobicity, as well as the Brønsted acidity, then assessed using catalytic hydrolysis of cyclohexyl acetate (to cyclohexanol) in water. The introduction of hydrophobic molecules to UIO-66 could prevent the material from being attacked by hydroxyl polar molecules effectively, explaining its good structural stability during catalysis. UIO-66−PhSO3H promoted the conversion of cyclohexyl acetate at ca. 87%, and its activity and textural properties were basically intact after the cyclic stability tests. The facile modification strategy can improve the hydrothermal stability of UIO-66 significantly, which can expand its catalytic applications in aqueous systems.

关键词： metal−organic frameworks (MOFs)     UIO-66     hydrolysis of cyclohexyl acetate     hydrophobicity     Brønsted acidity    

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Surface hydrophobicity: effect of alkyl chain length and network homogeneity

Wenqian Chen, Vikram Karde, Thomas N. H. Cheng, Siti S. Ramli, Jerry Y. Y. Heng

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 90-98 doi: 10.1007/s11705-020-2003-0

摘要： Understanding the nature of hydrophobicity has fundamental importance in environmental applications. Using spherical silica nanoparticles (diameter= 369€±€7 nm) as the model material, the current study investigates the relationship between the alkyl chain network and hydrophobicity. Two alkyl silanes with different chain length (triethoxymethylsilane (C1) vs. trimethoxy(octyl)silane (C8)) were utilised separately for the functionalisation of the nanoparticles. Water contact angle and inverse gas chromatography results show that the alkyl chain length is essential for controlling hydrophobicity, as the octyl-functionalised nanoparticles were highly hydrophobic (water contact angle= 150.6°€±€6.6°), whereas the methyl-functionalised nanoparticles were hydrophilic (i.e., water contact angle= 0°, similar to the pristine nanoparticles). The homogeneity of the octyl-chain network also has a significant effect on hydrophobicity, as the water contact angle was reduced significantly from 148.4°€±€3.5° to 30.5°€±€1.0° with a methyl-/octyl-silane mixture (ratio= 160:40 µL·g nanoparticles).

关键词： hydrophobicity     surface energy     wettability     alkyl chain network     silica nanoparticle    

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Incorporation of 3-dimensional lycopodium with hydrophobic nature and interconnected nano-channels into polyvinylidene fluoride membranes for desalination applications by vacuum membrane distillation

《化学科学与工程前沿（英文）》 2023年 第17卷 第9期   页码 1162-1182 doi: 10.1007/s11705-022-2276-6

摘要： In the present research, for the first time, lycopodium as a novel nanofiller was incorporated into a polyvinylidene fluoride matrix to fabricate lycopodium/polyvinylidene fluoride flat-sheet membrane for desalination applications by vacuum membrane distillation process. The prepared lycopodium/polyvinylidene fluoride membranes and lycopodium were characterized by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared, energy dispersive X-ray, and mapping analyses. Water contact angle and liquid entry pressure measurements were also performed. Response surface methodology was applied to optimize membrane structure and performance. The optimized lycopodium/polyvinylidene fluoride membrane exhibits superior performance compared to the neat polyvinylidene fluoride membrane in terms of flux, salt rejection, water contact angle, and hydrophobicity. In vacuum membrane distillation experiments, using a 15000 ppm NaCl solution as a feed at 70 °C, the neat polyvinylidene fluoride membrane, optimum membrane, and agglomerated membrane (with high lycopodium loading) demonstrated 3.80, 25.20, and 14.83 LMH flux and 63.30%, 99.99%, 99.96% salt rejection, respectively. This improvement in flux and salt rejection of the optimized membrane was related to the presence of lycopodium with hydrophobic nature and interconnected nano-channels in membrane structure. It was found that lycopodium, as the most hydrophobic material, effectively influences the membrane performance and structure for membrane distillation applications.

关键词： lycopodium     hydrophobicity     vacuum membrane distillation     desalination    

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用于润湿性控制的Stavax 钢基材的皮秒激光表面纹理处理 Article

Xincai Wang, 郑宏宇, Yinchi Wan, Wenhe Feng, Yee Cheong Lam

《工程（英文）》 2018年 第4卷 第6期   页码 816-821 doi: 10.1016/j.eng.2018.10.006

摘要：

在本文中，笔者采用皮秒激光来制造Stavax钢基板的表面纹理，此钢基板为制造各种高分子聚合物产品模具的关键材料。在Stavax 钢基板上主要有3种类型的表面纹理：周期性波纹、微凸块的双尺度分层二维阵列以及有纳米波纹的微坑阵列。经激光处理后的Stavax钢基板表面的润湿性从其原始的亲水性转变为疏水性，甚至在暴露于空气后具有超疏水性。研究结果清晰地表明，此超疏水性主要是由于表面纹理造成的。超快激光诱导的催化效果可能在改变表面化学性质方面起到次要作用，从而降低了表面能。随后，将金属磨具表面上的经激光处理的表面纹理通过高分子聚合物注射成型工艺复制到聚丙烯基底。由此，聚丙烯模具表面的润湿性从原始的亲水性变成疏水性。此开发工艺在改善塑料制品的湿润控制性和易清洗性方面具有一定潜能。

关键词： 皮秒激光     表面纹理处理     Stavax钢     高分子聚合物     疏水性    

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标题 作者 时间 类型 操作

Benzenesulfonic acid-grafted UIO-66 with improved hydrophobicity as a stable Brønsted acid catalyst

期刊论文

Surface hydrophobicity: effect of alkyl chain length and network homogeneity

Wenqian Chen, Vikram Karde, Thomas N. H. Cheng, Siti S. Ramli, Jerry Y. Y. Heng

期刊论文

Incorporation of 3-dimensional lycopodium with hydrophobic nature and interconnected nano-channels into polyvinylidene fluoride membranes for desalination applications by vacuum membrane distillation

期刊论文

用于润湿性控制的Stavax 钢基材的皮秒激光表面纹理处理

Xincai Wang, 郑宏宇, Yinchi Wan, Wenhe Feng, Yee Cheong Lam

期刊论文