Fabrication of polymer micro- and nanotubes with use of self-scrolling effect of strained thin polymer bilayer films.

近年来，我们开发了一种利用应变聚合物双层膜的自滚动制备介观直径和高纵横比聚合物管的新方法。薄膜中的应变是由于组成双分子层顶部和底部的聚合物在选择性溶剂中不同的膨胀而产生的。管状结构是在薄膜从衬底可控释放后形成的。我们已经用这种技术制备了聚苯乙烯-聚乙烯吡啶管，其直径范围从200纳米到5微米，长径比可达数百。该方法的主要优点是内管表面的复杂功能化的可能性。在滚动之前，聚合物薄膜可以暴露于高度发达的平面表面功能化方法（微接触印刷，光刻）。原则上，这允许在管内创建非平凡的三维模式排列，如螺旋、环等。具有复杂功能化内表面的管道可用于胶体颗粒和大分子的模板辅助自组装，蛋白质和其他生物分子与管壁的特定空间相互作用等。有趣的物理设备，如纳米螺线管，可以通过选择性金属化管的图案内表面产生。在这个项目中，我们追求两个主要目标。首先，我们计划优化纳米管的制造技术，以尽量减少管的直径。通过使用嵌段共聚物，在选择性衬底上形成层状结构，可以减少张力聚合物双层的厚度。我们希望用这种方法生产出直径小到几十纳米的管子。我们还打算制造从亚微米到亚毫米尺度的不同直径的管。这些管可以用于纳米器件的介观操作部分和宏观环境（试剂供应等）的输入输出连接。其次，我们计划将微接触印刷和光刻技术与自滚动效应相结合，制造具有简单而非琐碎的内表面图案的管。

Recently we have developed a novel method of producing polymer tubes of mesoscopic diameter and high aspect ratio with use of self-scrolling of strained polymer bilayer films. The strain in the film arises due to different swelling of the polymers, composing the top and the bottom parts of the bilayer, in a selective solvent. Tubular structures are formed upon controlled release of the film from the substrate. We have fabricated by this technique the polystyrene-polyvinylpyridine tubes with the diameters ranging from 200 nm to 5 microns and aspect ratios up to several hundreds. The major advantage of the approach is the possibility of complex functionalization of the inner tube surface. Before the scrolling, the polymer film can be exposed to highly developed planar methods of surface functionalization (micro-contact printing, photolithography). This allows in principle to create non-trivial 3-D arrangement of patterns inside the tubes, such as helices, rings, etc. The tubes with complex functionalized inner surface can be useful for template-assisted self-assembly of colloidal particles and macromolecules, specific steric interaction of proteins and other biomolecules with the tube walls, etc. Interesting physical devices, such as nanosolenoids, can be produced by selective metallisation of the patterned internal surface of the tubes. Within the project, we pursue two major goals. First, we plan to optimize the technique of nanotube fabrication in order to minimize the diameter of the tubes. The thickness of the strained polymer bilayer will be reduced by the use of block-copolymers, which form layered structure on selective substrates. In this way we hope to produce the tubes with diameter as small as few dozens of nanometers. We intend also to fabricate the tubes of varying diameter ranging from sub-micron to sub-millimeter scale. These tubes could be useful for input-output connection of mesoscopic operational parts of the nanodevices and the macroscopic environment (supplies of reagents, etc.). Second, we plan to fabricate the tubes with simple non-trivial patterning of the internal surface by combining the micro-contact printing and photolithography with the self-scrolling effect.