报告人：罗健平（Loh Kian Ping）

报告主题：Engineering Nanospace using 2D Polymer and 2D Covalent Organic Framework

时间：2023年4月12日下午15：30

地址：沧海校区致腾楼223室

Abstract

  2D polymer and 2D Covalent organic frameworks provides the material platform for engineering nanospace networks needed for selective ion-transport or molecular separation.  However, the crystallinity of these materials is limited by the irreversibility of some types of bond chemistry. It is also difficult to confine polymerization in the 2D plane in solution. We demonstrate a new class of 2D polymer derived from phenazine fused ring molecules, and show that a microporous thermoset, which can be processed like plastics and yet possess a rigid framework with well-defined nanoporosity, can be synthesized [1]. Microporous thermoset polymer is highly useful as ion transport channel and gas diffusion membrane.

  Despite progress made in synthesizing COFs of diverse topologies, the synthesis methods are often tedious and unscalable, hampering practical applications. By considering the relationship between layer packing arrangement and the ability to restrict intramolecular rotation, we demonstrate a scalable, robust method of producing highly crystalline acylhydrazone two-dimensional (2D) COFs with diversified structures under open and stirred conditions, with growth typically completed in only 30 min [2]. The difference between COF and 2D polymer can be demonstrated by tuning interlayer interactions in the case of COF to achieve white light emission [3]. Using hydrazine COF as a solid state electrolyte in lithium ion battery, we achieved an ion conductivity of 10−5 S cm−1 at −40 °C with a Li+ transference number of 0.92. Using 1,4-benzoquinone as the cathode, a lithium battery using hydrazine COF as a SE runs for 500 cycles at a steady current density of 500 mA g−1 at 20 °C. We also demonstrate the use of functionalised COF in high-loading Li-S batteries, as well as multi-atmosphere Li batteries [5,6]. Finally, we consider the question of how to render 2D COF, which is actually quasi-2D, truly 2D. Our strategy involves the integration of mechanically interlocked molecular architectures (MIMAs) into quasi-2D COF. Depending on the number of layers of COF that can be interlocked per molecular complex, this affords a strategy to partition the interlayer space into pseudo-unit cells, from which we can exfoliate high yield monolayer or bilayer COF [7].

References

1.Wei Liu, K. P. Loh, et al. Nature Chemistry, 9, 563–570 (2017)

2.Xing Li, Kian Ping Loh* Journal of the American Chemical Society, 142, 10, 4932–494 (2020)

3. Xing Li and Kian Ping Loh* et. al.　NATURE COMMUNICATIONS, 9, 2335 (2018)

4.Xing Li, Kun Zhang, Junhao Lin* and Kian Ping Loh* Nature Synthesis 1, 382–392 (2022)

5.  Xing Li, Kun Zhang, Keyu Xie*, Kian Ping Loh* Angewandte Chemie International Edition, 2202826(2023)

6. Xing Li, Kian Ping Loh* et al. NATURE CHEMISTRY. 12, 1115-1122 (2020).

Kian Ping Loh

新加坡国立大学教务长讲座教授

香港理工大学理学院应用物理学系终身讲席教授

罗健平(Loh Kian Ping)教授是亚洲材料科学院院士、新加坡国立大学化学系首席教授暨石墨烯研究中心领衔人，新加坡国立大学教务长讲座教授，香港理工大学理学院应用物理学系终身讲席教授。罗健平于1994年获得新加坡国立大学学士学位，1996年获得牛津大学化学系博士学位，1997年受聘为研究员并于日本国立材料科学研究所从事独立研究，1998年受聘为新加坡国立大学化学系助理教授，2012年晋升为正教授，曾任新加坡国立大学化学系系主任、新加坡国立大学教务长讲座教授，现为先进二维材料中心主任及深圳大学-新加坡国立大学光电科技协同创新中心外方主任。罗健平教授作为负责人承担了新加坡国家研究基金支持的CPF, NRF等重大科研项目，目前已在Nature, Science正刊及其系列子刊以通讯作者发表论文40余篇，并在JACS, Advanced Materials等其他顶级杂志发表论文多达400余篇，引用超过70,000次，连续多次入选材料、物理、化学三大领域的全球高被引学者。其作为主要申请人获得专利10余项，其中大面积生长和转移石墨烯的专利已获得主要国家和地区的专利保护。

罗健平教授因其卓越的研究水平，于2008年获得新加坡国立大学青年研究员奖，2012年获得新加坡国立大学杰出研究员奖，2013年获得美国化学会纳米技术奖，2014年被授予新加坡最高科学奖——总统科学奖。罗健平目前担任美国化学会杂志《Chemistry of Materials》副编辑、英国物理会杂志《2D Materials》副主编、以及《Advanced Functional Materials》等杂志的国际顾问委员会成员。目前，罗健平教授已培养国内外教授40余名（含新加坡国立大学正教授1名，副教授1名，新加坡南洋理工大学、香港理工大学、香港中文大学、北京大学等助理教授、南京大学、西安交通大学、天津大学、北京理工大学、华中科技大学、华南理工大学等正教授，中科院化学所、长春光机所、苏州纳米所等研究员），其中18人获国家级青年人才称号。

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