Summary: A novel photosensitive fluorinated poly(arylene ether) containing chalcone units was synthesized from decafluorinated chalcone and fluorinated bisphenol at low temperature. Upon UV irradiation, the refractive indices of the polymer film were decreased because of the reduction of electronic polarizability in the chalocone moiety. The decrease was more significant in the in‐plane direction than in the out‐of‐plane direction, and consequently, zero birefringence (at 632.8 nm) was obtained after 90 s of exposure.
The changes in the refractive indices and the birefringence of chalcone‐containing fluorinated poly(arylene ether) films synthesized and measured at 632.8 nm with respect to UV irradiation time. 相似文献
A matrix method is proposed for describing polarization properties of biological tissues as an aggregate of uniaxial crystal
structures. We investigated 25 μm-thick histological sections of compact bone tissue which provided single light scattering.
It is shown that in this case there exists a unique relationship between the polarization parameters of the boundary laser
field and the parameters of anisotropy and orientation of the structural elements of biological tissue. On this basis, contactless
methods of laser polarimetry of histological sections of bone tissue have been proposed.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 1, pp. 52–55, January–February, 2000. 相似文献
Anion sensing via either optical or electrochemical readouts has separately received enormous attention, however, a judicious combination of the advantages of both modalities remains unexplored. Toward this goal, we herein disclose a series of novel, redox-active, fluorescent, halogen bonding (XB) and hydrogen bonding (HB) BODIPY-based anion sensors, wherein the introduction of a ferrocene motif induces remarkable changes in the fluorescence response. Extensive fluorescence anion titration, lifetime and electrochemical studies reveal anion binding-induced emission modulation through intramolecular photoinduced electron transfer (PET), the magnitude of which is dependent on the nature of both the XB/HB donor and anion. Impressively, the XB sensor outperformed its HB congener in terms of anion binding strength and fluorescence switching magnitude, displaying significant fluorescence turn-OFF upon anion binding. In contrast, redox-inactive control receptors display a turn-ON response, highlighting the pronounced impact of the introduction of the redox-active ferrocene on the optical sensing performance. Additionally, the redox-active ferrocene motif also serves as an electrochemical reporter group, enabling voltammetric anion sensing in competitive solvents. The combined advantages of both sensing modalities were further exploited in a novel, proof-of-principle, fluorescence spectroelectrochemical anion sensing approach, enabling simultaneous and sensitive read out of optical and electrochemical responses in multiple oxidation states and at very low receptor concentration. 相似文献