Structurally Asymmetric Porous Carbon Materials with Ordered Top Surface Layers from Nonequilibrium Block Copolymer Self-Assembly
Structurally Asymmetric Porous Carbon Materials with Ordered Top Surface Layers from Nonequilibrium Block Copolymer Self-Assembly
复制标题
非平衡嵌段共聚自组装制备结构不对称的顶层有序多孔炭材料
DOI：
10.1021/acs.macromol.0c02720
复制
发表时间：
2021-03-04
期刊：
影响因子：
5.5
通讯作者：
Wiesner, Ulrich
中科院分区：
文献类型：
--
作者：
Hesse, Sarah A.;Beaucage, Peter A.;Wiesner, Ulrich
具有不对称孔结构的无机材料提供了更多的可及性和通量，使其在能量转换和存储、分离和催化方面的应用具有吸引力。基于非平衡的嵌段共聚物定向自组装方法为获得此类材料提供了途径。本文报道了用共组装和非溶剂诱导相分离（CNIPS）法一锅合成聚（异戊二烯）-b-聚（苯乙烯）-b-聚（4-乙烯基吡啶）（ISV）三嵌段三元共聚物和苯酚甲醛溶剂。热处理后的碳材料具有不对称孔隙结构。它们具有沿膜法向渐变孔隙度的多孔支撑顶部的介孔顶表面。大孔支架的壁也是介孔的，提供了额外的结构层次和增加的比表面积。我们展示了如何成功地导航与CNIPS的非平衡方法相关的路径复杂性，从而在热处理后的有机-有机杂化物和所得碳材料中从无序到有序的顶部表面切换。为此，结合了膜涂料溶液的非原位透射小角x射线散射（SAXS）、涂料溶液叶片后和溶剂蒸发过程中的原位掠入射x射线散射（GISAXS）和最终膜结构的扫描电镜（SEM）。我们期望最终的多孔碳材料具有不对称的、分层的孔隙结构和明确的介孔结构，在电池、燃料电池、电化学双层电容器和催化剂载体等许多应用中都有应用。
Inorganic materials with asymmetric pore structures provide increased accessibility and flux, making them attractive for applications in energy conversion and storage, separations, and catalysis. Non-equilibrium-based block copolymer structure-directed self-assembly approaches provide routes to obtaining such materials. We report a one-pot synthesis using the co-assembly and non-solvent-induced phase separation (CNIPS) of poly(isoprene)-b- poly(styrene)-b-poly(4-vinylpyridine) (ISV) triblock terpolymer and phenol formaldehyde resols. After heat-treatment, carbon materials with asymmetric pore structures result. They have a mesoporous top surface atop a porous support with graded porosity along the film normal. The walls of the macroporous support are also mesoporous, providing an additional structural hierarchy and increased specific surface area. We demonstrate how successfully navigating the pathway complexity associated with the nonequilibrium approach of CNIPS enables switching from disordered to ordered top surfaces in the as-made organic-organic hybrids and resulting carbon materials after thermal treatments. To that end, a combination of ex situ transmission small-angle X-ray scattering (SAXS) of the membrane dope solutions, in situ grazing-incidence SAXS (GISAXS) after dope solution blading and during solvent evaporation, and scanning electron microscopy (SEM) of the final membrane structures was used. We expect the final porous carbon materials exhibiting a combination of asymmetric, hierarchical pore structures and well-defined mesoporosity throughout the material to be of interest for a number of applications, including batteries, fuel cells, electrochemical double-layer capacitors, and as catalyst supports.