In Situ All‐Weather Humidity Visualization by Using a Hydrophilic Sponge

Abstract

the humidity monitoring and evaluating require the sensitive materials with the features of short response and recovery times, as well as diverse-configuration compatibility, that can meet the spatial and temporal humidity gradients measurements. [8][9][10][11][12][13][14][15] To date, many efforts have been performed for the fabrication of sensitive materials, including metal oxides, ceramics, perovskites, carbon compounds, and organic polymers, to realize high-performance humidity monitoring. [16][17][18][19][20] However, the complicated steps for device construction, the low flexibility, as well as the extreme dependence on external energy-supply systems or coupled circuits, have obstructed to some extent the broad application of these reported sensor devices. [21][22][23][24][25] Therefore, it is of significance to develop new humidity-sensitive materials with enhanced working performance, that is, wide detection range, short response

Atmospheric humidity-triggered reversible spin-state switching

“…2b), which can act as a channel for the transmission of small molecules. 31 IR spectra have suggested that the connement in the sponge has made a signicant inuence on the intermolecular interactions of 2D-SCO@UCNPs, as the vibrational peaks for SCN (at around 2000 cm −1 ) have decreased dramatically in the sponge (Fig. 2c).…”

“…1. 2D-SCO, UCNPs, 2D-SCO@UCNPs, and the naked sponge were prepared according to our previous work; [31][32][33][34][35][36] their transmission electron microscopy (TEM) images are presented at the bottom of Fig. 1.…”

“…Considering that the porous features can promote small molecules, such as water, through the sponge, we then focus on the practical application of the sponge in a humid environment, to achieve the ambition of "energy conservation", that is, atmospheric humidity-triggered spin-state switching. For this purpose, the 2D super hygroscopic material, 31,35 which featured efficient humidity capture capacity under ambient conditions, as well as fast water release triggered by natural sunlight, has been employed. As shown in Fig.…”

“…Here in this work, via connement of a two-dimensional (2D) SCO material into a hygroscopic sponge, the atmospheric humidity-triggered reversible spin-state switching under ambient conditions has been achieved. The related sponge was composed of a hydrophobic polymer poly(vinylidene uoride) (PVDF) and a hydrophilic polymer polyethylene glycol (PEG), 31 which act as a three-dimensional bracket that disperses the 2D SCO material in space. The related 2D SCO material was an NIRsensitive species 2D-SCO@UCNPs (Fig.…”

Hydrophilic–hydrophobic hybrid gel for effective humidity capture and response

“…26,27 Polyvinylidene fluoride (PVDF) is a crystalline polymer membrane material, which has unique chemical stability, heat resistance, and mechanical stability. [28][29][30] PVDF gel has received much attention as a three-dimensional (3D) framework material. 31 Poly-N-isopropyl acrylamide (PNIPAM), which is hydrophilic and can form a hydrophilic network for water storage, was added to weaken the hydrophobic properties of PVDF.…”