自潤滑材料在油水分離的應用與分離性能之研究

Abstract

本研究是使用以聚二甲基矽氧烷（PDMS）為基材的自潤滑材料，探討其在油水分離應用中的性能，實驗中我們製備了四種自潤滑材料：純PDMS、10SO-PDMS、40TEG-PDMS和TEG-SO-PDMS，探討了其濕潤性變化、自修復能力及油水分離的性能，實驗結果顯示，浸泡矽油的PDMS顯著改善了材料的表面濕潤性，在不大幅改變接觸角的情況下，水滴和油滴的遲滯角(CAH)大幅減少至10°以下，使液滴的滑動性明顯提升，同時潤滑層的形成受潤滑液的滲入量和分布情況所影響，當PDMS浸泡矽油的時間延長，會使潤滑層厚度從約347nm增至868nm，增強了材料的耐久性與自修復性能。 在油水分離的應用中，自潤滑PDMS海綿展現了卓越的吸油能力，10SO-PDMS海綿的吸油速度相較於純PDMS海綿提高了約1.8倍，顯示由矽油形成的潤滑層增強了吸油性能，此外使用金屬網塗層的分離結果表明，矽油層的存在降低了侵入壓力，使油滴可以快速滲透孔洞，而水滴會被有效的阻擋在金屬網上，在分離持續流動的油水混合物時，10SO-PDMS金屬網塗層的分離效率為89%，但分離速度提升了約2.5倍，展現出其優異的分離性能與穩定性。 微流道實驗進一步驗證了潤滑層對液體流動性的增強效果，其中10SO-PDMS表面的液體流速比純PDMS表面快約三倍，此外浸泡不同黏度矽油的PDMS微流道表現出顯著的差異，10cSt黏度的矽油能快速均勻滲入微流道表面，形成穩定潤滑層，顯著提升液體的流動速度，較高黏度矽油則滲透速率較慢，液體流動速度的提升幅度較小，表明潤滑液的黏度會影響微流道中液體的流動性能。 綜上所述，我們透過改善表面的濕潤性和潤滑層，顯著提升了油水分離性能，並在中高黏度油品的分離中表現出色，改善了其他油水分離技術在分離中高黏度油品性能較差的問題，而且本研究中的製備方法簡單，可以適用在油水分離技術中的吸收型和過濾型材料，對於環境也很友善。

This study investigates the performance of self-lubricating materials based on polydimethylsiloxane (PDMS) for oil-water separation applications. Four types of self-lubricating materials were prepared: pure PDMS, 10SO-PDMS, 40TEG-PDMS, and TEG-SO-PDMS. The changes in wettability, self-healing ability, and oil-water separation performance were explored. Experimental results showed that PDMS soaked in silicone oil significantly improved the surface wettability of the material. Without substantially altering the contact angle, the contact angle hysteresis (CAH) for water and oil droplets was reduced to below 10°, significantly enhancing droplet mobility. The formation of the lubricating layer was influenced by the infiltration and distribution of the lubricant. Prolonged soaking in silicone oil increased the lubricating layer thickness from approximately 347 nm to 868 nm, enhancing the durability and self-healing properties of the material. In oil-water separation applications, self-lubricating PDMS sponges exhibited excellent oil absorption capabilities. The oil absorption rate of 10SO-PDMS sponges was approximately 1.8 times higher than that of pure PDMS sponges, demonstrating that the silicone oil-based lubricating layer improved oil absorption performance. Furthermore, the results from metal mesh coatings indicated that the presence of a silicone oil layer reduced the intrusion pressure, allowing oil droplets to pass through the pores quickly while effectively blocking water droplets on the metal mesh. During the continuous separation of oil-water mixtures, the separation efficiency of 10SO-PDMS metal mesh coatings was 89%, with the separation speed increasing by approximately 2.5 times, showcasing outstanding separation performance and stability. Microchannel experiments further validated the lubricating layer’s effect on enhancing liquid flow. On 10SO-PDMS surfaces, the liquid flow rate was approximately three times faster than that on pure PDMS surfaces. Additionally, PDMS microchannels soaked in silicone oil with different viscosities exhibited significant differences. Silicone oil with a viscosity of 10 cSt rapidly and uniformly infiltrated the microchannel surface, forming a stable lubricating layer and significantly enhancing liquid flow. In contrast, higher-viscosity silicone oils infiltrated more slowly, resulting in smaller improvements in liquid flow rates. This demonstrates that the viscosity of the lubricant affects liquid flow performance within microchannels. In summary, we significantly enhanced oil-water separation performance by improving surface wettability and the lubricating layer. The developed materials performed exceptionally well in separating medium-to-high viscosity oils, addressing the limitations of other oil-water separation techniques in handling such oils. Moreover, the preparation method in this study is simple, adaptable to both absorption-based and filtration-based oil-water separation materials, and environmentally friendly.