Colloids and Surfaces A: Physicochem. Eng. Aspects 443 (2014) 195–200 Contents lists available at ScienceDirect Colloids and Surfaces A: Physicochemical and Engineering Aspects jo ur nal ho me page: www.elsevier.com/locate/colsurfa Pore size effect on the formation of polymer nanotubular structures within nanoporous templates Younghyun Cho a,1 , Chanhui Lee b,1 , Jinkee Hong c,∗ a School of Chemical & Biological Engineering, Seoul National University, Seoul 151-744, Republic of Korea b Department of Plant and Environmental New Resources, Kyung Hee University, Yongin 446-701, Republic of Korea c School of Chemical Engineering and Materials Science, Chung-Ang University, Seoul 156-756, Republic of Korea h i g h l i g h t s • Cylindrical nanoporous templates with various pore diameters were synthesized. • Polymer nanotubes were obtained based on the template-assisted sur- face modification by nano-films. • Wall thickness of the nanotubes was affected by the pore size of porous templates. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 9 September 2013 Received in revised form 2 November 2013 Accepted 9 November 2013 Available online 18 November 2013 Keywords: Polymer nanotube Nanoporous template Anodic aluminum oxide membrane Multilayer Layer-by-layer deposition a b s t r a c t Nanotubular structures have recently received much attention due to their potential applications in biosensors, drug delivery systems, electronic devices, and many others. The layer-by-layer (LbL) deposi- tion technique on 3-dimensional templates has been one of the most popular methods for the formation of nanotubular structures. Any size, shape, and composition template can be utilized and the desired amount of various materials can be readily incorporated within the thin film geometry with nanoscale control. Therefore, the morphological features of those materials can easily be tuned by varying the structural properties of templates. However, LbL deposition within a confined geometry actually shows somewhat different results due to the geometrical restriction, which is still not fully understood so far. In the present study, in order to investigate such a template effect on the LbL process, we utilized a cylin- drical nanoporous anodic aluminum oxide (AAO) structure as a template for the LbL process, yielding polymer nanotube structures. By varying the pore size of the porous templates, we determined the LbL process within porous structures was strongly governed by the geometrical characteristics of the utilized templates. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Recently, nanotube structures incorporating a variety of func- tional materials have received considerable attention as one of the most versatile and important materials for broad ranges of applications ranging from electronic devices to drug delivery ∗ Corresponding author. Tel.: +82 2 820 5561; fax: +82 2 824 3495. E-mail addresses: jkhong@cau.ac.kr, jkhong.cau@gmail.com (J. Hong). 1 These authors contributed equally. systems [1–4]. Among various preparation methods to realize such nanotube structures, the layer-by-layer (LbL) deposition on 3- dimensional porous templates has been regarded as one of the most powerful and popular methods for the creation of nanotube struc- tures because the typical advantages of the LbL deposition method on 2-dimensional flat substrates yielding multilayered thin films can also be easily extended to 3-dimensional porous substrates, leading to nanotube structures [5–13]. The versatility of the LbL method has allowed a wide range of materials to be assembled on the basis of complementary interactions including polymers, nanoparticles, graphene, proteins, and DNA [14–18]. The amount of 0927-7757/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.colsurfa.2013.11.013