Tailoring morphology in titania nanotube arrays by implantation: experiments and modelling on designed pore size—and beyond

Titania nanotube arrays are an exceptionally adaptable material for various applications ranging from energy conversion to biomedicine. Besides electronic properties, structural morphology on nanometre scale is essential. It is demonstrated that ion implantation constitutes a versatile method for the synthesis of tailored nanotube morphologies. Experimental-phenomenological observations reveal a successive closing behaviour of nanotubes upon ion implantation. Employing molecular dynamics calculations in combination with analytical continuum models, the physical origins of this scenario are unravelled by identifying ion bombardment induced viscous flow driven by capillarity as its underlying mechanism besides minor contributions from sputtering and redeposition. These findings enable the tailoring of nanotube arrays suitable for manifold applications. This work presents a unified framework for understanding and predicting ion-induced effects in nanotube structures by a combination of experiments, modelling and analytical theory.

二氧化钛纳米管阵列（Titania Nanotube Arrays）是一类适配性优异的多功能材料，可应用于从能量转换到生物医药等诸多领域。除电子特性外，纳米级的微观结构形貌同样至关重要。研究表明，离子注入（Ion Implantation）是一种可用于定制化制备目标纳米管形貌的通用手段。实验与现象学观测结果显示，纳米管在离子注入过程中会呈现出逐步闭合的行为特征。本研究结合分子动力学（Molecular Dynamics）计算与解析连续介质模型，通过分析揭示了该现象的物理本质：其核心机制为离子轰击诱导的、由毛细作用驱动的粘性流动，而溅射（Sputtering）与再沉积（Redeposition）仅起到次要贡献。上述研究成果可实现针对各类应用场景的定制化纳米管阵列制备。本工作通过实验、建模与解析理论相结合的方式，构建了一套可用于理解并预测纳米管结构中离子诱导效应的统一理论框架。