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Traditional polarization converters suffer from drawbacks such as significant thickness and high losses, which limit their practical applications. This study introduces a novel metamaterial structure that combines electromagnetically induced transparency (EIT) with linear polarization conversion to overcome these limitations. By harnessing the properties of EIT, this structure achieves low‐loss polarization conversion. The mechanism behind this is the generation of an EIT effect through the coupling of the light and dark modes. Additionally, this study focuses on introducing a slight vertical polarization symmetry disruption and inducing the excitation of small components within the dipole of the EIT structure to achieve close‐to‐complete cross‐polarization conversion. The effect of asymmetry on the polarization conversion rate is also explored. This study offers an innovative approach to designing low‐loss polarization converters utilizing EIT technology. [ABSTRACT FROM AUTHOR]

In this study, poly(1-butyl-3-vinylimidazolium bromide) (PBVIm-Br) was grafted onto the poly(vinyl chloride) (PVC) membrane surface via a 2-step atom transfer radical polymerization (ATRP) reaction. Poly(2-hydroxyethylmethacrylate) (PHEMA) was grafted onto the membrane surface by aqueous ATRP reaction; then, BVIm-Br was introduced onto the surface of the PHEMA-modified PVC membrane through traditional ATRP reaction. The analysis of surface chemistry confirmed the successful grafting of PHEMA and PBVIm-Br on PVC membrane surface, and the grafting density (GD) of PBVIm-Br gradually increased as the grafting time was prolonged. The modified membrane exhibited a positive charge and significantly enhanced surface hydrophilicity. The static water contact angle of the membrane surface decreased from 92.3° to 51.6° as the GD of the PBVIm-Br brushes increased. Filtration experiments indicated that the water flux of the modified membrane increased with increasing GD, and their recovered fluxes were more than twice than the original. In addition, the total fouling ratio of the membranes decreased from 89% in M0 to 67% in M5, and most of the fouling was reversible as the GD of PBVIm-Br brushes increased. These results indicated that the positive charged poly(ionic liquid) brushes featuring hydrophilic properties would have potential applications in membrane separation. [ABSTRACT FROM AUTHOR]