Hydrogels with open environment stability are of great significance in the fields of microelectronics, organ regeneration, and hydrogel-based sensors. Although a series of strategies for exploring highly robust hydrogels have been proposed, it is still challenging to improve environmental stability while maintaining the original dispersed medium feature. Here, 1-vinyl-3-butylimidazolium (VBIM) and acrylic acid (AA) are used as the anionic and cationic monomers to prepare zwitterionic hydrogels through the thermal initiation polymerization. The prepared PAA-IL (polyacrylic acid- co -ionic liquid) hydrogel forms a large number of multi-hydration, including hydrogen bonds and ion-dipole interactions with water to inhibit the freezing and volatilization of water, and it possesses good structural stability due to the formation of ion bond self-association through interchain charge interaction. The robust stability of the chemical sensor with PAA-IL hydrogels as the substrate at different pH and temperature verifies the validity of the proposed design strategy. It is expected that the present zwitterionic hydrogel design strategy would shine a light on the exploration of environment-stable hydrogels and hydrogel-based chemical sensors.
Jie Ji,Rui Cui,Li Liang,Heng Xu,Haozhe Li,Xiang Ke,Xiang Zhou,Xiaode Guo
To improve the pressure output ability of nanothermites to meet the needs in many fields, with the more volatile advantage of metal fluoride products (AlF3), this paper proposes the scheme of nanothermites (Al/CuF2). The energy release process of Al/CuF2 with different equivalent ratios under slow and fast heating rates has been studied. Under the slow heating rates, it was found that the equivalent ratio (Φ) has a significant influence on the energy release process. When Φ ≤ 1, the product is dominated by Cu. With the increase of the equivalent ratio, Al2Cu gradually appeared in the product, indicating that the increase of Al powder contributed to the enhancement of the alloy reaction. On the other hand, to further investigate the actual application of the Al/CuF2 mixture, combustion experiments in a closed container and in open air were carried out and compared with those of Al/CuO. In accordance with our design concept, AlCuF2 shows more excellent gas release ability. Al/CuF2 (Φ = 3) has the most excellent pressure output capacity (2.67 MPa), which increases by 107% compared to 1.29 MPa (Al/CuO). In addition, Al/CuF2 displays more excellent ignition performances in terms of shorter delay time and less ignition energy. Therefore, Al/CuF2 composite particles, as a novel nanothermite design, are expected to be widely used in the gas generator, micropropulsion, and other military and civilian fields.
危险品化学品经营许可证（带存储）