General Strategy to Prepare Nondoped Circularly Polarized Luminescent Liquid Crystal Materials with Tunable Performance

Sha Huang; Yahan Wen; Xincan Wang; Yuan Cheng; Yongjie Yuan; Hailiang Zhang

doi:10.1021/acsami.3c18617

General Strategy to Prepare Nondoped Circularly Polarized Luminescent Liquid Crystal Materials with Tunable Performance

ACS Appl Mater Interfaces. 2024 Feb 21;16(7):9323-9332. doi: 10.1021/acsami.3c18617. Epub 2024 Feb 9.

Authors

Sha Huang¹, Yahan Wen¹, Xincan Wang¹, Yuan Cheng², Yongjie Yuan¹, Hailiang Zhang¹

Affiliations

¹ Key Laboratory of Polymeric Materials and Application Technology of Hunan Province, Key Laboratory of Advanced Organic Functional Materials of Colleges and Universities of Hunan Province, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China.
² Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, Instrumentation and Service Center for Molecular Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024, China.

PMID: 38334091
DOI: 10.1021/acsami.3c18617

Abstract

Chiral luminescent liquid crystals have attracted widespread attention from researchers due to their unique advantages in constructing circularly polarized luminescent (CPL) materials with large luminescent asymmetry factor (g_lum) values. However, how to effectively prepare nondoped CPL chiral liquid crystals remains a challenge. In this article, we developed an effective and universal method to prepare nondoped CPL chiral liquid crystal materials. To achieve our strategy, we copolymerized chiral monomer M0Mt with α-cyanostilbene-based luminescent monomers MmPVPCN (m = 6, 8, 10) bearing different flexible spacer lengths to obtain a series of CPL chiral liquid crystal copolymers poly(MmPVPCN(x)-co-M0Mt(y)). Under the induction of the chiral component, the α-cyanostilbene component assembles to form chiral liquid crystals. Meanwhile, α-cyanostilbene also exhibits aggregation-induced emission enhancement characteristics. Therefore, with the help of the selective reflection effect of chiral liquid crystals, the copolymer films can emit efficient CPL. For poly(M8PVPCN(0.85)-co-M0Mt(0.15)), the g_lum and solid luminescence quantum yield can achieve -2.61 × 10^-2 and 25.04%, respectively. In addition, by altering the chemical structure of the copolymers, the phase structure of the copolymers can be effectively controlled, thereby regulating their CPL properties.

Keywords: chiral smectic C-phase liquid crystal; cholesteric liquid crystal; circularly polarized luminescence; copolymerization; side-chain liquid crystal copolymer.