Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003, USA.
Proc Natl Acad Sci U S A. 2012 Jan 31;109(5):1402-6. doi: 10.1073/pnas.1115803109. Epub 2012 Jan 17.
A simple, versatile approach to the directed self-assembly of block copolymers into a macroscopic array of unidirectionally aligned cylindrical microdomains on reconstructed faceted single crystal surfaces or on flexible, inexpensive polymeric replicas was discovered. High fidelity transfer of the line pattern generated from the microdomains to a master mold is also shown. A single-grained line patterns over arbitrarily large surface areas without the use of top-down techniques is demonstrated, which has an order parameter typically in excess of 0.97 and a slope error of 1.1 deg. This degree of perfection, produced in a short time period, has yet to be achieved by any other methods. The exceptional alignment arises from entropic penalties of chain packing in the facets coupled with the bending modulus of the cylindrical microdomains. This is shown, theoretically, to be the lowest energy state. The atomic crystalline ordering of the substrate is transferred, over multiple length scales, to the block copolymer microdomains, opening avenues to large-scale roll-to-roll type and nanoimprint processing of perfectly patterned surfaces and as templates and scaffolds for magnetic storage media, polarizing devices, and nanowire arrays.
我们发现了一种简单、通用的方法，可以将嵌段共聚物定向自组装成在重构的具有面心立方结构的单晶表面或柔性、廉价的聚合物复制品上沿单方向排列的圆柱微区的宏观阵列。还展示了从微区到主模具的高保真线图案转移。无需使用自上而下的技术即可在任意大的表面区域上形成单晶粒线图案，其序参量通常超过 0.97，斜率误差为 1.1 度。这种在短时间内达到的完美程度，是其他任何方法都无法实现的。这种优异的取向源于面心立方结构中链堆积的熵罚与圆柱微区的弯曲模量的结合。从理论上讲，这是能量最低的状态。原子晶体有序的衬底在多个长度尺度上被转移到嵌段共聚物微区，为大规模卷对卷型和纳米压印处理提供了完美图案化表面的途径，并作为模板和支架用于磁存储介质、偏光器件和纳米线阵列。
