华东理工大学朱为宏团队报道了具有抗疲劳和可逆性的光重构非均匀软螺旋节距。相关研究成果发表在2022年11月7日出版的国际学术期刊《美国化学会杂志》。

在光子学、化学和材料领域迫切需要在远端和完全可逆的光中对光谱进行主动工程和调制。然而，由于缺乏合适的光响应候选器件，诸如波长、带宽、反射率和偏振等多种光学信息的实时调节仍然是一个长期存在的问题。

该文中，研究人员提出了光调制软螺旋中的额外“自由度（DOF）”，并建立了具有光重构特性、抗疲劳性和可逆性的前所未有的非均匀螺距长度。对于工作模型，采用本征手性光开关LBC5作为致动器来调制与辐射强度成比例的螺旋节距长度，并且引入独特的宽带吸光度光调制器BTA-C5作为透射光的衰减器，以沿样品厚度降低其强度，在节距长度上仅具有单个DOF的普通软螺旋之外，成功地在节距分布上添加了另一个受控DOF（即均匀或非均匀）。

具有独特的可变宽带吸收的吸光度光调制器BTA-C5使光能够将螺旋节距从均匀变为不均匀，从而实现可逆光谱编程的鲁棒抗疲劳性建立。利用光响应调制器BTA-C5建立的光可重构非均匀螺距，可以提供控制吸光度和手性的突破，特别是用于根据需要动态加宽和变窄带宽，并进一步实现具有高达1.88的高不对称因子glum的所需宽带NIR圆偏振发光（CPL）。尖端的可光开关非均匀软螺旋螺距为软材料、光学、生物光子学和其他相关领域提供了多自由度控制。

附：英文原文

Title: Light-Reconfiguring Inhomogeneous Soft Helical Pitch with Fatigue Resistance and Reversibility

Author: Mengqi Li, Honglong Hu, Binghui Liu, Xuan Liu, Zhi-Gang Zheng, He Tian, Wei-Hong Zhu

Issue&Volume: November 7, 2022

Abstract: Active engineering and modulation of optical spectra in a remote and fully reversible light is urgently desired in photonics, chemistry, and materials. However, the real-time regulation of multiple optical information such as wavelength, bandwidth, reflectance, and polarization is still a longstanding issue due to the lack of an appropriate photoresponsive candidate. Herein, we propose an additional “degree-of-freedom (DOF)” in a photo-modulated soft helix, and build up an unprecedented inhomogeneous helical pitch length with light-reconfiguring property, fatigue resistance, and reversibility. For the working model, the intrinsic chiral photoswitch LBC5 is employed as an actuator to modulate the helical pitch length, which is proportional to the irradiation intensity, and the unique broadband absorbance photo-modulator BTA-C5 is incorporated as an attenuator of the transmitted light to decrease its intensity along the sample thickness, therefore successfully adding another controlled DOF on the pitch length distribution (i.e., homogeneous or inhomogeneous) apart from the common soft helix with only a single DOF on the pitch length. The absorbance photo-modulator BTA-C5 with a unique variable broadband absorption enables the light to reconfigure the helical pitch from homogeneous to inhomogeneous, thereby achieving the robust fatigue-resistance establishment of reversible spectral programming. The established light-reconfigurable inhomogeneous helical pitch with the photoresponsive modulator BTA-C5 can provide a breakthrough to control absorbance and chirality, especially for dynamically broadening and narrowing the bandwidth on demand, and further enable the ever-desired broadband NIR circularly polarized luminescence (CPL) with a high dissymmetry factor glum of up to 1.88. The cutting-edge photoswitchable inhomogeneous soft helical pitch provides access to multi-freedom control in soft materials, optics, biophotonics, and other relevant fields.

DOI: 10.1021/jacs.2c08505

Source: https://pubs.acs.org/doi/10.1021/jacs.2c08505