以氧化錳及細菌纖維素製備一新穎吸油抗菌薄膜之分析之應用

Abstract

由於逐漸上升的人口數與水資源不足造成未來飲用水可能缺乏的隱憂，近年來有許多科學家投入淨化水資源的研究。從海上油污到水中的有機化合物與重金屬離子，研究者發表了許多方式致力於能達到簡單的淨化水資源為目的。本篇研究利用具有大體表面積之特殊八面分子篩結構之氧化錳作為吸油材料，並將此氧化錳與細菌纖維素作結合形成一吸油複合薄膜，最後在此複合薄膜表面上還原奈米銀粒子形成吸油抗菌之複合薄膜。 首先，我們透過水熱法與回流法兩種不同合成法成功合成八面分子篩氧化錳，並經由SEM、TEM、EDS等儀器比較兩方法得到產物之微結構與組成成份等基本性質，另外也透過BET及BJH分析法量測氧化錳之體表面積與孔徑大小及分佈。研究同時培養木質醋酸菌數日並萃取其代謝之細菌纖維素作為強化薄膜結構之材料，接著，將八面分子篩氧化錳與細菌纖維素結合透過熱壓法製膜並量測此薄膜表面跟水/油之溼潤性和吸油效果，我們另外也可以透過鍍上PDMS來使薄膜表面從親水性改變為疏水性，而薄膜同時也透過TGA熱重分析儀測量其熱穩定度。最後透過還原奈米銀的方式使薄膜具有抑制細菌生長的效果。此新穎薄膜經實驗證實能成功有效抑制抗藥性金黃色葡萄球菌(革蘭氏陽性菌)與鮑氏不動桿菌(革藍氏陰性菌)的生長長達24小時。由於此薄膜具有良好吸油能力與有效抗菌效果，未來有極大的潛力可應用於淨化生活中的廢水處理領域。

The lack of the water resource and drinking water will be a potential problem due to the critical pollution and increasing population. In recent years, many scientists are devoted into the study of water purification for removal of water pollutions, such as the occurrence of oil spillage on water surface, the organic compounds and heavy metal ions in water. In this thesis, we successfully fabricate a composite membrane integrated with oil absorption ability and antibacterial property. We found, a cryptomelane-type manganese oxide (K-OMS-2) whose particular octahedral sieve structure has large surface area was used as an oil absorption material. The K-OMS-2 would be mixed with bacterial cellulose (BC) substrate and thereby form a hybrid membrane system; antimicrobial activity, then, could be achieved by the reduction of silver nanoparticles (AgNPs) on the substrate surface. First, the K-OMS-2 synthesized by hydrothermal method and reflux method was compared in their basic characteristics by SEM, EDS, TEM and SAED; the surface area and pore-size distribution were investigated by BET and BJH analysis. Next, we employ the BC that was produced by incubation of Gluconobacter xylinum bacteria in a static culture for several days as a strong substrate for composition. After hybrid with K-OMS-2, the contact angles of oil/water on the surface and oil absorption ability were measured. Hydrophilic and oleophilic performances were displayed at the same time, but PDMS coating can modulate water adhesion phenomenon from hydrophilicity into hydrophobicity. Also, the hybrid membrane has thermal stability from TGA test. Finally, good antimicrobial activity was exhibited by the reduction of AgNPs on the membrane surface. The results were proved to be effective on inhibition for the growth of both Methicillin-resistant Staphylococcus aureus (MRSA) (Gram-positive bacteria) and Acinetobacter baumannii (AB) (Gram-negative bacteria) for 24 hours. Due to the good oil absorption and effective antibacterial property, this novel composite membrane has the potential for applications of wastewater treatment.