Xinhong Han,Yiwen Xue,Rui Lou,Shaoqiu Ding,Shurong Wang
Sorption dehumidification, as an energy-saving and eco-friendly approach, has been emerging in application for air dehumidification. Here, a prospective method is proposed to prepare biomass-based hygroscopic aerogels that are easily applicable, sustainable, high-efficient, and recyclable. The chitosan-based aerogel with a porous and hydrophilic network acts as the carrier and water reservoir for the uniformly distributed lithium chloride hygroscopic salt, and provides the hygroscopic salt with more liberal water channels to facilitate moisture capture and transfer. As a consequence, the prepared chitosan/polyvinyl alcohol@lithium chloride (chitosan/PVA@LiCl) hygroscopic aerogel exhibits an excellent moisture absorption capacity of up to 2.77 g g −1 at a relative humidity of 90 %. Meanwhile, as the chitosan/PVA@LiCl aerogel is set in a closed space about 2200 times larger than its own volume, the relative humidity can be reduced from 90 % to 32 % within 2 h, and further lower to 25 % after 4 h. Furthermore, combined with multi-walled carbon nanotubes, the photothermal hygroscopic aerogel is obtained that can rapidly desorb water under sunlight, thus to realize energy-free cycle. Overall, the renewable biomass-based aerogel materials with the advantages of simple preparation and excellent hygroscopic performance provides a new path for the development of sorption dehumidification technology.
Shiyi Wang,Yingzi Zhang,Yuxin Yan,Xuehua Dong,Liling Cao,Ling Huang,Guohong Zou
Birefringent crystals are essential in laser modulation, optical communication, and imaging systems. This paper reports two tellurium-based hybrid birefringent crystals─(C12H9N2)2TeBr6·2H2O and (C12H9N2)2TeBr6─composed of Te4+-centered octahedral units and [C12H9N2]+ π-conjugated organic cations. The hydrate converts to the anhydrate via thermal dehydration, a process in which water removal eliminates steric hindrance, promoting a more ordered molecular arrangement. Optical measurements show significantly enhanced birefringence after dehydration. The value at 546 nm increases from 0.17 to 0.31, nearly doubling. These findings highlight the potential of such materials for advanced optical applications that require high birefringence.