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Feng et al. Chem Synth 2023;3:37 https://dx.doi.org/10.20517/cs.2023.26 Page 5 of 16

Figure 2. Schematic illustration of the synthesis of the 2D mesoporous PPy nanosheets. This figure is quoted with permission from Liu
et al. [42] . APS: Ammonium persulfate; PPy: polypyrrole; THF: tetrahydrofuran; 2D: two-dimensional.

As a kind of lightweight 2D materials with abundant functional groups, 2D polymers show good
performance in adsorption, energy storage, and sensors [43-46] . Our group synthesized 2D mesoporous
[47]
polydiaminopyridines (MPDAPs) through a multi-dimensional molecular self-assembly strategy
[Figure 3]. In this strategy, block copolymer polystyrene polyethylene oxide (PS-b-PEO) first self-assembles
into zero-dimensional spherical micelles and then combines with DAP molecules through hydrogen bonds
to form composite micelles of mDAP/mPS-b-PEO. At the same time, perfluorinated tetradecanoic acid
(PFCA) molecules formed 2D organic substrates [mesoporous PFCA (mPFCA)] in mixed solvents. Based
on a hydrogen bond, mPFCA is co-assembled with mDAP/mPS-b-PEO and rapidly polymerized into a
polymer under the induction of ammonium persulfate. After the removal of PFCA and PS-b-PEO by
washing with ethanol and 1, 4-dioxane multiple times, 2D MPDAPs were obtained. By changing the
molecular weight of PS-b-PEO, the mesoporous size of MPDAPs can be effectively adjusted. Due to their
abundant amino groups and pyridine nitrogen sites, the MPDAPs obtained showed high catalytic activity in
the Knoevenagel condensation reaction.

As described above, molecular self-assembly is a general synthesis method for the controlled synthesis of
ordered porous structures, which can achieve precise control of the composition, coordination
environment, and nanostructure of the designed catalysts. However, due to the poor structural stability of
layered micelles of block copolymers, it has been difficult to synthesize ordered 2D layered structures by
using layered micelles.

SINGLE MICELLE ASSEMBLY METHOD
For the last few years, detailed research has been conducted on the self-assembly of micelles and skeleton
precursors into mesoporous structures at liquid-solid, liquid-liquid, and gas-liquid interfaces to construct
functional mesoporous materials with different chemical compositions, 2D morphologies, and mesoporous
structures. In comparison with the single-phase solution synthesis method, introducing a two-phase
interface in the synthesis environment alters the self-assembly behavior between micelles and skeleton
materials, thus making it possible to customize the synthesis of unique mesoporous structures.
Furthermore, regulating interfacial tension is essential for controlling the self-assembly process to achieve