Please use this identifier to cite or link to this item:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88474
Title: | 具有自修復性質之高分子薄膜 : 真空輔助修復及氣體分離應用 Self-healing polymer membrane: vacuum-assisted treatment and gas separation application |
Authors: | 洪耀偉 Yao-Wei Hong |
Advisor: | 康敦彥 Dun-Yen Kang |
Keyword: | 自修復雙嵌段高分子,薄膜氣體分離,CO2/N2分離,氫鍵修復,金屬有機骨架,混合基質薄膜, self-healing copolymer,membrane gas separations,CO2/N2 separations,hydrogen bond,metal organic framework,mixed matrix membrane, |
Publication Year : | 2023 |
Degree: | 碩士 |
Abstract: | 薄膜氣體分離技術相較於傳統氣體分離技術(如:低溫蒸餾、吸附)有著較低的能耗,為近十年被廣泛研究的新興技術。然而,當薄膜表面受到外力破壞產生裂痕,將會大幅降低薄膜的氣體分離表現。本研究利用具有自修復能力的高分子薄膜(self-healing polymer membrane),不僅解決裂痕問題,也可延長材料的使用壽命。我們利用刮刀塗佈法製備出兩種緻密的高分子薄膜PBA0.8-co-PNMA0.2與PBA0.8-co-PMAA0.2,並將商用PEBAX-1657氣體分離膜做為對照組,比較這三種材料在機械性質與分離表現的修復效果。透過拉伸試驗,我們發現經過氫鍵修復的PBA0.8-co-PNMA0.2與PBA0.8-co-PMAA0.2薄膜,其機械性質可修復,且其自修復效率達到84.22 % 與88.63 %,而PEBAX-1657 則無法修復機械性質。在氣體分離表現方面,我們發現在真空幫浦的輔助下,可加速薄膜的修復效率。PBA0.8-co-PNMA0.2與PBA0.8-co-PMAA0.2薄膜在破壞後60秒內展現阻氣效果,而PEBAX-1657薄膜上仍存在傷口,導致壓力無法回降。將PBA0.8-co-PNMA0.2薄膜保持在真空環境下修復12小時,其薄膜的分離表現得以維持,其修復後的CO2/N2選擇率為22.92(破壞前的選擇率為17.36);反觀PEBAX-1657在同樣操作下,其修復後的CO2/N2選擇率大幅下降至0.96(破壞前的選擇率為20.09)。未使用真空系統修復的情況下,PBA0.8-co-PNMA0.2薄膜的CO2/N2選擇率下降為1.12,且SEM正面照中仍存在傷口;然而使用真空系統修復後,PBA0.8-co-PNMA0.2薄膜上的傷口明顯消失。最後,為了進一步檢測材料的耐用程度,我們進行了多次破壞測試,結果顯示真空修復後可恢復PBA0.8-co-PNMA0.2薄膜的分離表現,展示了其強韌的自修復特性。
此外,我們也將PBA0.8-co-PNMA0.2與金屬有機骨架CAU-10-H進行混摻,製備成混合基質薄膜(mixed matrix membranes, MMMs),希望利用CAU-10-H優異的分離特性來提升薄膜的分離效果,同時利用PBA0.8-co-PNMA0.2的自修復能力賦予材料分離性能修復的特性。實驗結果顯示,混合基質薄膜內部存在填充物與高分子匹配度差的問題,導致薄膜內部形成了許多空洞。這些空洞降低了薄膜的分離性能,同時在拉伸過程中也產生應力集中現象,降低了材料的機械強度。最後,我們還對混合基質薄膜進行破壞,並發現在真空系統的輔助下,薄膜也展現出了優異的阻氣能力。 Over the past decade, membrane-based gas separation technology has emerged as a highly investigated solution to address the energy-intensive nature of conventional separation technologies such as cryogenic distillation and adsorption. However, cracks on the membrane significantly reduce their separation capabilities. To address this issue, we fabricated two self-healing copolymer membranes, PBA0.8-co-PNMA0.2 and PBA0.8-co-PMAA0.2, via casting method. We compared mechanical properties and gas separation performance recovery capabilities of these membranes to commercially available PEBAX-1657 membrane. We applied NMR, IR, TGA, and DSC for the structure characterization. Besides, the mechanical properties could be completely recovered through hydrogen bonding. As for the recovery of gas separation performance, PBA0.8-co-PNMA0.2 and PBA0.8-co-PMAA0.2 membranes showed gas-resistance capabilities within 60 seconds of being cut, whereas there was a crack on PEBAX-1657 membrane. The CO2/N2 selectivity of PBA0.8-co-PNMA0.2 membrane could recover to 22.92 with vacuum-assisted treatment, while that of PEBAX-1657 membrane decreased to 0.96 under the same process. Additionally, we applied the constant-pressure method and SEM to verify the importance of vacuum system. Without the vacuum-assisted treatment, the CO2/N2 selectivity of PBA0.8-co-PNMA0.2 membrane decreased to 1.12, and there was a wound on the membrane. To investigate the limits of the self-healing capabilities of PBA0.8-co-PNMA0.2, we created a cross-wound by making two cuts on membranes. The results demonstrated the gas permeation properties of PBA0.8-co-PNMA0.2 membrane were not affected by the double wounds, indicating robust self-healing capabilities. In addition, we incorporated CAU-10-H as the filler along with PBA0.8-co-PNMA0.2 to fabricate the mixed matrix membranes(MMMs). The intention was to leverage the exceptional gas separation capabilities of CAU-10-H to enhance the separation performance of MMMs, while also harnessing the remarkable self-healing properties of PBA0.8-co-PNMA0.2 to restore the gas separation performance after being cut. However, the experimental results revealed a challenge with the compatibility between the filler and polymer, leading the formation of numerous voids within the membranes. These voids not only compromised the separation performance, but also weakened the mechanical strength of membranes. Despite this challenge, the MMMs still demonstrated good gas-resistant capabilities following vacuum-assisted treatment. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88474 |
DOI: | 10.6342/NTU202302353 |
Fulltext Rights: | 同意授權(全球公開) |
Appears in Collections: | 化學工程學系 |
Files in This Item:
File | Size | Format | |
---|---|---|---|
ntu-111-2.pdf | 4.82 MB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.