Nishimura Taiki, Katsuhara Satoshi, Lee Chaehun, Ree Brian J, Borsali Redouane, Yamamoto Takuya, Tajima Kenji, Satoh Toshifumi, Isono Takuya
Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
Nanomaterials (Basel). 2022 May 12;12(10):1653. doi: 10.3390/nano12101653.
Block copolymers (BCPs) have garnered considerable interest due to their ability to form microphase-separated structures suitable for nanofabrication. For these applications, it is critical to achieve both sufficient etch selectivity and a small domain size. To meet both requirements concurrently, we propose the use of oligosaccharide and oligodimethylsiloxane as hydrophilic and etch-resistant hydrophobic inorganic blocks, respectively, to build up a novel BCP system, i.e., carbohydrate-inorganic hybrid BCP. The carbohydrate-inorganic hybrid BCPs were synthesized via a click reaction between oligodimethylsiloxane with an azido group at each chain end and propargyl-functionalized maltooligosaccharide (consisting of one, two, and three glucose units). In the bulk state, small-angle X-ray scattering revealed that these BCPs microphase separated into gyroid, asymmetric lamellar, and symmetric lamellar structures with domain-spacing ranging from 5.0 to 5.9 nm depending on the volume fraction. Additionally, we investigated microphase-separated structures in the thin film state and discovered that the BCP with the most asymmetric composition formed an ultrafine and highly oriented gyroid structure as well as in the bulk state. After reactive ion etching, the gyroid thin film was transformed into a nanoporous-structured gyroid SiO material, demonstrating the material's promising potential as nanotemplates.
嵌段共聚物（BCPs）因其能够形成适用于纳米制造的微相分离结构而备受关注。对于这些应用而言，实现足够的蚀刻选择性和小的畴尺寸至关重要。为了同时满足这两个要求，我们提出分别使用寡糖和寡聚二甲基硅氧烷作为亲水性和抗蚀刻的疏水性无机嵌段，以构建一种新型的BCP体系，即碳水化合物 - 无机杂化BCP。碳水化合物 - 无机杂化BCP是通过在每个链端带有叠氮基的寡聚二甲基硅氧烷与炔丙基官能化的麦芽寡糖（由一个、两个和三个葡萄糖单元组成）之间的点击反应合成的。在本体状态下，小角X射线散射表明，这些BCP微相分离成螺旋状、不对称层状和对称层状结构，其畴间距根据体积分数在5.0至5.9nm范围内。此外，我们研究了薄膜状态下的微相分离结构，发现具有最不对称组成的BCP在本体状态下也形成了超细且高度取向的螺旋状结构。经过反应离子蚀刻后，螺旋状薄膜转变为纳米多孔结构螺旋状SiO材料，证明了该材料作为纳米模板的潜在应用前景。
