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In this paper, a polarization selective broad/triple-band metamaterial absorber based on SiO2 all-dielectric is designed and studied. The absorber works in a long infrared band (8–14 μm). It is composed of cuboid and trapezoidal silica structures in the upper layer and metal plates in the lower layer. We calculate the absorption results of the metamaterial absorber at different polarization angles as the polarization angle of incident light increases from 0° to 90°; that is, the light changes from Ex polarization to Ey polarization. The results show that the absorption rate of the structure is more than 90% in the range of 8.16 to 9.61 μm when the polarization angle is 0°. When the polarization angle of the incident light is less than 45°, the absorption result of the absorber does not change significantly. When the polarization angle of the incident light is greater than 45°, three absorption peaks appear in the long infrared band, realizing the selectivity of the polarization of the incident light. When the polarization angle increases to 90°, the absorptivity of the two absorption peaks at λ = 9.7 μm and 12.3 μm reaches more than 85%. In addition, the sensitivity analysis of the length, width, and thickness of the all-dielectric metamaterial absorber and the calculation of the electric field of this structure are also carried out. The designed all-dielectric metamaterial absorber has polarization selection and perfect absorption characteristics and has a broad application prospect.

Agricultural chemical residue in the environment is one of the biggest concerns for biosafety and human health worldwide. Here, we develop a carrier for pesticides by the chemical combination of UiO-66 and sodium alginate (Alg). When clothianidin (CTD) was encapsulated in UiO-66/Alg, they showed the ability to act as controlled-release pesticides with double stimuli-responsive. Although only 62.74% of CTD was released at 27 °C in 144 h, 93.52% was released at 45 °C at the same time, and the release could be tuned by adding phosphate at the time of greatest requirement. Moreover, the UV-irradiating stability of CTD in UiO-66/Alg was >3.5 times greater than for free CTD, which combined with the outstanding biosafety of UiO-66/Alg-CTD illustrates its potential for development as a bio-friendly, stable and intelligent carrier of pesticides to improve the utilization efficiency of pesticides.