The development of synthetic two-dimensional crystalline polymers (2DCPs), such as 2D covalent-organic polymers and 2D metal-organic polymers, is receiving increasing attention due to their intriguing chemistry and unique properties, as well as potential role in wide ranging applications, such as electronics, sensing, catalysis, separation, and energy storage and conversion. Complementary to the top-down exfoliation towards the preparation of 2DCPs, bottom-up interface-assisted synthesis is advantageous in the 2D dynamic arrangement of the molecules or precursors, offering the chance to generate ultra-thin structures with large lateral sizes. This article provides guidelines on the preparation of free-standing, single-layer, or multi-layer 2DCPs via liquid-interface-assisted synthesis, mainly involving polymerization at the air–water and liquid–liquid interfaces, as well as the Langmuir-Blodgett method. Insight into the advantages and challenges of synthesis strategies and chemistry methodologies are provided for the future development of interfacial synthesis of 2DCPs with diverse structural and functional control.

合成二维晶体聚合物（2DCP）的开发，例如2D共价有机聚合物和2D金属有机聚合物，由于其令人着迷的化学性质和独特的性能以及在广泛应用中的潜在作用而受到越来越多的关注，例如电子，传感，催化，分离以及能量存储和转换。自上而下的剥离辅助2DCP的制备，自下而上的界面辅助合成在分子或前体的2D动态排列中是有利的，从而提供了产生具有大横向尺寸的超薄结构的机会。本文提供了有关通过液体界面辅助合成制备独立式，单层或多层2DCP的指南，主要涉及空气-水和液体-液体界面的聚合，以及Langmuir-Blodgett方法。深入了解了合成策略和化学方法的优势和挑战，为具有不同结构和功能控制的2DCP界面合成的未来发展提供了条件。