二氧化鈦光觸媒被覆於碳鋼之防蝕能力、表面親水性以及抗菌性之研究

The Influence of Titanium Oxide coating on Carbon Steels in the Aspects of Corrosion Mitigation, Photo-induced Hydrophilicity and Anti-bacterial Behavior

高偉陞(Wei-Sheng Kao)

指導教授 ： 葉宗洸

國立清華大學/原子科學院/工程與系統科學系/碩士(2020年)

摘要

本研究利用溶膠凝膠法 (Sol-gel method)製備二氧化鈦膠體並將其被覆於碳鋼
(Carbon Steel, CS)以及氧化銦錫導電玻璃上(Indium tin oxide, ITO)，分別探討二氧化鈦被
覆在碳鋼與ITO上所呈現的腐蝕防制、光誘發表面親水性以及抗菌性等三種特性。首先，
在腐蝕防制部分，直接將二氧化鈦被覆於碳鋼表面，鍛燒過程中鐵離子會擴散進入二氧
化鈦薄膜內，使光催化效果降低，因此必須將碳鋼進行預長氧化膜處理，本實驗探討不
同預長氧化膜條件以及鍛燒熱處理的組合，讓二氧化鈦擁有良好結晶性的同時，鐵離子
也能有效被阻隔，實驗結果顯示最佳腐蝕防制參數為：碳鋼預氧化 600°C 維持 5 分鐘，
被覆二氧化鈦並熱處理 400°C 維持 60 分鐘，電位由-54mVAg/AgCl 降低到-263mVAg/AgCl，
電位變化為-210mV，電流密度由 1.24 x 10-8A/cm2 降低到 4.49 x 10-13 A/cm2，約 4 個數量
級。接著在光誘發表面親水性的部分，利用接觸角量測儀量測不同氧化膜之水接觸角，
再觀察被覆完二氧化鈦後的水接觸角，最後再照射紫外光探討二氧化鈦光催化表面親水
的性質，結果顯示被覆完二氧化鈦後，表面都變得比被覆前疏水，在照射紫外光下，水
接觸角會接近 0°，顯示此時極親水的現象 (Super-hydrophilic)。最後在抗菌性的部分，
首先觀察大腸桿菌(Escherichia coli, E.coli)在指定培養基生長的情形，每隔一段時間觀察
菌落形成單位 (Colony Forming Unit, CFU)，並繪製出生長曲線，結果顯示 0-1.5 小時為
潛伏期，1.5-7 小時為指數生長期，倍增時間(doubling time)約為 23 分鐘，7-24 小時為平
坦期，飽和 E.coli 菌液密度大約在 1-2 x 109 CFU/ml，到了 24 小時之後進入死亡期。接
著將生長曲線顯示之飽和 E.coli 菌液置於 ITO.TiO2、CS、CS.TiO2、control 等表面並搭
配 100%、10%、5%與 1% 強度之紫外光照射，探討細胞生存情形，繪製出存活曲線，
結果顯示紫外光強度降低會使細菌存數量上升，且在不同紫外光強度照射下，抗菌效果
由高至低依序皆為 ITO.TiO2、CS.TiO2、CS、Control。本研究成功利用溶膠凝膠法製備
出二氧化鈦，並能顯著地抑制腐蝕情形、紫外光照射下呈現完全親水以及一定程度的抗
菌性。

關鍵字

二氧化鈦 ； 腐蝕防制 ； 光誘發表面親水性 ； 抗菌性

並列摘要

In this study, carbon steels (CSs) and Indium tin oxide (ITOs) with a titanium oxide(TiO2)
coating applied by the sol-gel method were investigated in three aspects, including preventing
or minimizing the atmospheric corrosion, photo-induced surface hydrophilicity and anti
bacterial properties. In the corrosion mitigation part, if TiO2 was directly coated on plain CS
and then annealed, the photocatalytic effect was poor. During the thermal treatment process,
iron atoms would diffuse from CS to TiO2 and limit the photocatalytic effect. Therefore, the
pre-oxidation process was necessary. Various oxide structures of carbon steel and the TiO2
thermal treatment process were investigated in this study. According to the experiment results,
the optimum processing parameter was pre-oxidizing on carbon steel at 600°C for 5 min,
coating TiO2 and then conducting thermal treatment at 400°C for 60min. Electrode potential
decreased from -54mVAg/AgCl to -263mVAg/AgCl, and the potential difference was -210mV .
Current density decreased from 1.237 x 10-8A/cm2 to 4.489 x 10-13 A/cm2 about four orders of
magnitude drop. In the photo-induced surface hydrophilicity part, we first used the sessile drop
method to measure the contact angle(CA) of different oxide films and we observed the CA of
TiO2 coated specimens and then measured the CA changes under UV illumination. These results
indicated that after coating the TiO2 on the pre-oxidized carbon steels, the CA increased while
under UV illumination the CA would decrease to almost 0°,which is a super-hydrophilic surface.
Last, in the anti-bacterial properties part, we first observed the Escherichia coli growth under
designated medium by measuring the colony forming unit (CFU) every a period of time and
draw a growth curve. Results showed that in the first 1.5h is lag phase, during 1.5-7 h is
exponential phase and doubling time is about 23 min, during 7-24h is stationary phase and the
maximum cell density of 1-2 x 109 CFU/ml is observed, after 24h is in dead phase. Then the
saturated E. coli bacteria solution (1-2 x 109) derived in the growth curve was placed on
different surfaces, i.e. ITO.TiO2, CS.TiO2, CS, Control, and irradiated with 100% and 10%

iii

intensity ultraviolet light (UV) to explore the viability of the cells and draw a survival curve.
These results reveal that no matter under 100% or 10% UV intensity the viable cell density
sequence from high to low was ITO.TiO2, CS.TiO2, CS, Control. This study concluded that the
titanium oxide prepared by the sol-gel method can significantly inhibit the corrosion behavior,
and it is completely hydrophilic under ultraviolet irradiation and has a certain degree of
antibacterial properties.

並列關鍵字

Titanium ； Corrosion ； Hydrophilicity ； Anti-bacterial

參考文獻

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