中国科学院长春应用化学研究所Mao Li研究组近日取得一项新成果。经过不懈努力，他们开发出了具有高模量和导电性的结晶单聚合物单层膜。这一研究成果发表在2022年11月28日出版的国际学术期刊《德国应用化学》上。

在该研究中，研究人员通过同步电合成和操纵，合成了具有高于ITO衬底的超高模量和高电导的结晶单聚单分子膜。研究组发现，聚合物单层在垂直方向和单一方向上已经完全扩展，这导致其接近其所有凝聚态中理论上最高的密度、模量和电导率。这一聚合物的模量和电流密度可达到其非晶态的40倍和1000倍。

研究人员还发现，这些单分子层表现出偏置和长度相关的多重电荷态和非对称负微分电阻(NDR)效应，表明这种独特的分子定制和排序设计在多层电阻存储器件中很有前途。该工作展示了如何构建接近聚合物电子材料物理极限的晶体聚合物单分子层，也为挑战孤立超长聚合物的迭代合成极限提供了机会。

据介绍，为实现聚合物材料的最高物理特性，合成具有明确的定向态和尺寸超过微米的二维晶体的晶态聚合物是必不可少的，但仍然具有挑战性。

附：英文原文

Title: Crystalline Unipolymer Monolayer with High Modulus and Conductivity

Author: Jinxin Wang, Hao Zhang, Shumu Li, Caijun Ding, Yongjie Zhao, Xiuzhen Long, Chang Wei, Yanfang Wang, Yongfang Li, Lingyun Shen, Shuxun Cui, Wenjing Hong, Mao Li

Issue&Volume: 2022-11-28

Abstract: The synthesis of crystalline polymer with a well-defined orientated state and a two-dimensional crystalline size beyond a micrometer will be essential to achieve the highest physical feature of polymer material but remain challenging. Herein, we show the synthesis of the crystalline unipolymer monolayer with an unusual ultrahigh modulus that is higher than the ITO substrate and high conductance by simultaneous electrosynthesis and manipulation. We find that the polymer monolayer has fully extended in the vertical and unidirectional orientation, which is proposed to approach their theoretically highest density, modulus, and conductivity among all aggregation formations of the current polymer. The modulus and current density can reach 40 and 1000 times higher than their amorphous counterpart. It is also found that these monolayers exhibit the bias- and length-dependent multiple charge states and asymmetrically negative differential resistance (NDR) effect, indicating that this unique molecular tailoring and ordering design is promising for multilevel resistive memory devices. Our work demonstrates the creation of a crystalline polymer monolayer for approaching the physical limit of polymer electronic materials and also provides an opportunity to challenge the synthetically iterative limit of an isolated ultra-long polymer.

DOI: 10.1002/anie.202216838

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202216838