Kim Minsoo P, Kim Hyeong Jun, Kim Bumjoon J, Yi Gi-Ra
School of Chemical Engineering, Sungkyunkwan University, Suwon, 440-746, Korea.
Nanotechnology. 2015 Mar 6;26(9):095302. doi: 10.1088/0957-4484/26/9/095302. Epub 2015 Feb 11.
We present a novel method for producing structured nanoporous thin films using block copolymer (BCP) micelles loaded with metallic ions. The BCP micellar thin films containing gold (Au) ions were prepared by spin-coating poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) micelle solutions in which Au precursors (AuCl4(-)) were selectively loaded onto the P4VP core. When the micellar films were exposed to cetyltrimethylammonium bromide (CTAB) solutions, the Au precursors were selectively extracted from the P4VP domains due to their strong electrostatic interaction with CTAB, leading to the formation of pores in the micelles. Consequently, regularly patterned nanoporous surfaces were formed. By controlling the molecular weight (Mn) of PS-b-P4VP and the amount of Au precursors (λ) that were loaded in the P4VP domains, the pore size and depth could be tuned precisely. In particular, when a sufficient amount of Au precursors was loaded (λ ≥ 0.3), the porous surface nanostructure was well developed. In addition, the pore size and depth of the nanostructure increased as the λ value increased. For instance, when the λ value increased from 0.3 to 1.0, the pore size increased from 22.8 nm to 28.8 nm, and the pore depth increased from 2.1 nm to 3.2 nm. Interestingly, the transition from the nonporous structures to the porous structures in the micellar film could be reversibly controlled by adding and removing the Au precursors in the film. Moreover, our method for the preparation of nanoporous films can be extended to micellar film by incorporating other metal ions such as silver (Ag) and iron (Fe).
我们提出了一种利用负载金属离子的嵌段共聚物（BCP）胶束制备结构化纳米多孔薄膜的新方法。通过旋涂聚（苯乙烯 - 嵌段 - 4 - 乙烯基吡啶）（PS - b - P4VP）胶束溶液制备含金（Au）离子的BCP胶束薄膜，其中Au前驱体（AuCl4(-)）被选择性地负载到P4VP核上。当胶束薄膜暴露于十六烷基三甲基溴化铵（CTAB）溶液时，由于Au前驱体与CTAB之间强烈的静电相互作用，它们被选择性地从P4VP域中萃取出来，导致胶束中形成孔隙。因此，形成了规则图案化的纳米多孔表面。通过控制PS - b - P4VP的分子量（Mn）以及负载在P4VP域中的Au前驱体的量（λ），可以精确调节孔径和深度。特别是，当负载足够量的Au前驱体（λ≥0.3）时，多孔表面纳米结构发育良好。此外，纳米结构的孔径和深度随着λ值的增加而增大。例如，当λ值从0.3增加到1.0时，孔径从22.8 nm增加到28.8 nm，孔深从2.1 nm增加到3.2 nm。有趣的是，通过在薄膜中添加和去除Au前驱体，可以可逆地控制胶束薄膜中从无孔结构到多孔结构的转变。此外，我们制备纳米多孔薄膜的方法可以通过引入其他金属离子如银（Ag）和铁（Fe）扩展到胶束薄膜。
