以浸鍍法於金屬表面製備多孔性聚乳酸薄層之研究

Study of dip-coating on metal surface with porous PDLLA

蘇泰綸(Tai-Lun Su)

指導教授 ： 方旭偉

國立臺北科技大學/工程學院/化學工程研究所/碩士(2007年)

https://doi.org/10.6841/NTUT.2007.00153

摘要

本實驗旨在利用浸鍍法(dip-coating)塗佈多孔性聚乳酸(PDLLA)於金屬表面。大致上分成兩部分，首先，由於薄層厚度需要靠經驗來控制，使得製備薄層有很大的盲目性；基於此考量，我們以流體力學的角度分析浸鍍法之流變性質，從中找出薄層厚度、拉伸速度與溶液黏度之間的關係，以此作為後續實驗操作的參考依據。此外；嘗試以溼式相轉換法(wet phase inversion method)來改變薄層結構性質，藉由浸入不同非溶劑與添加聚乙二醇(PEG)於製膜液中來調控結構。
實驗結果顯示，薄層厚度隨著浸鍍溶液黏度提高而增大，而隨著拉伸速度漸增而先增後減，這個現象與重力效應有直接的關聯。溼式製膜實驗中，製備純聚乳酸薄層，藉以改變製膜液濃度、非溶劑種類與浸入非溶劑前停留時間來觀察薄層結構：溶劑含量等同被置換空間多寡，所以濃度低的製膜液會形成孔隙度較佳的結構；溶劑-非溶劑間的親合性會造成置換速率不同而形成不同型態孔洞分佈；而浸入非溶劑前停留時間越長，受到揮發效應影響，造成緻密表層結構。在添加PEG部份，利用PEG當作增孔劑，最後將PEG利用水去除，得到更具連通性的多孔PDLLA薄層。

關鍵字

浸鍍法 ； 聚乳酸 ； 溼式相轉換法 ； 製膜液 ； 非溶劑 ； 聚乙二醇

並列摘要

The aim of this work was to apply dip-coating that coat metal with porous PDLLA membrane. First, because the thickness of coating needs controlling by experience, Therefore, from reology nature of dip-coating, we find out the thickness of coating related among the pull-out speed and viscosity of solution, regard this as reference of follow-up experiment. Moreover, try to changing different nonsolvents and additive PEG in casting solution to adjusting coatings structure with wet phase inversion method.
Experimental results showed that the thickness of coating increases with the viscosity of solution, and reduce after specific pull-out speed. This phenomenon had direct relation with gravity effect. In wet phase inversion experiment, we change concentration of casting solution、nonsolvents and the time before dipping in nonsolvent bath to observing coatings: Lower concentration casting solution form better porosity. The affinity between solvent-nonsolvent was cause difference exchange rate to form distinct morphology. And by evaporation effect, the more evaporation time, the thicker surface structure. In addition PEG part, eliminate PEG by water to form much pores.

並列關鍵字

dip-coating ； PDLLA ； wet phase inversion method ； casting solution ； nonsolvent ； PEG (Polyethylene Glycols)

參考文獻

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