Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA.
Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA; Micron Technology, Inc., Boise, ID 83716, USA.
Colloids Surf B Biointerfaces. 2014 Mar 1;115:280-5. doi: 10.1016/j.colsurfb.2013.11.038. Epub 2013 Dec 10.
Surface wettability characteristics of commercially pure titanium (CP-Ti/Ti-II) and titanium Grade 5 alloy (Ti-6Al-4V/Ti-V) with 10nm-thick atomic layer deposited (ALD) TiO2 from Tetrakis DiEthyl Amino Titanium and water vapor were studied in conjunction with cleaning steps before and after the ALD treatment. The wettability characteristics of rough Ti-II and Ti-V samples were investigated after each step, that is, as received, after de-ionized (DI) water rinse followed by N2 drying, sonication in methanol, ALD treatment, and post-ALD DI water rinse. Samples without ALD or cleaning treatments were hydrophobic to variable extents, depending on exposure to different environments, surface impurities, roughness, and aging. Surface treatments reported in the literature resulted in hydrophilic/hydrophobic surfaces likely due to organic and/or inorganic impurities. In this study, (i) it is established that it is critically important to probe surface wettability after each substrate treatment; (ii) both Ti-II and Ti-V surfaces are found to become more hydrophilic after each one of the sequential treatments used; and (iii) independently of the initial wettability characteristics of Ti-II and Ti-V surfaces, the aforementioned treatments result in a water contact angle well below 10°, which is an important factor in cellular response. X-ray photoelectron spectroscopy of ALD titania films indicated trace impurities in them. Grazing incidence X-ray diffraction suggested amorphous ALD TiO2 at 200 °C; anatase TiO2 was obtained with as little as 5 min annealing at 600 °C in nitrogen.
研究了具有 10nm 厚原子层沉积（ALD）TiO2 的商用纯钛（CP-Ti/Ti-II）和钛 5 级合金（Ti-6Al-4V/Ti-V）的表面润湿性特征，这些 TiO2 是由四乙氧基钛和水蒸气制成的。在进行 ALD 处理前后，对清洁步骤进行了研究。研究了粗糙 Ti-II 和 Ti-V 样品在每一步之后的润湿性特征，即原始状态、去离子（DI）水冲洗后、氮气干燥、甲醇超声处理、ALD 处理以及 ALD 后 DI 水冲洗。未经 ALD 或清洁处理的样品在不同程度上具有疏水性，这取决于暴露于不同的环境、表面杂质、粗糙度和老化。文献中报道的表面处理导致亲水/疏水性表面，这可能是由于有机和/或无机杂质的存在。在这项研究中：（i）确定在每次基底处理后探测表面润湿性至关重要；（ii）发现 Ti-II 和 Ti-V 表面在每一种连续处理后都变得更加亲水；（iii）无论 Ti-II 和 Ti-V 表面的初始润湿性特征如何，上述处理都会导致水接触角低于 10°，这是细胞反应的一个重要因素。ALD 二氧化钛薄膜的 X 射线光电子能谱表明其中存在痕量杂质。掠入射 X 射线衍射表明，在 200°C 下形成无定形 ALD TiO2；在氮气中仅在 600°C 下退火 5 分钟即可获得锐钛矿 TiO2。
