Xunshuang Zhang,Junxiang Wu,Yu He,Chenhao Zhao,Minfang An,Liangbin Li
Lithium (Li) reserves in liquid resources are significantly higher than solid lithium ores and can fully meet the growing demand for Li. Lithium-ion sieves (LIS) adsorption of Li from liquid resources is one of the most promising methods. However, conventional polymeric adsorption materials encapsulate most LIS in dense structures, leading to low adsorption capacity and slow adsorption rate. Therefore, HTO-PVA/PAAm hydrogel was synthesized from titanium-type lithium-ion sieves (HTO), acrylamide, and polyvinyl alcohol by free radical polymerization. The HTO-PVA/PAAm hydrogel is characterized by a soft three-dimensional (3D) network, continuously adjustable pore structure, high specific surface area, and excellent hydrophilicity. Accordingly, the HTO-PVA/PAAm owns an excellent Li + adsorption capacity (22.16 and 31.31 mg·g −1 in pH 7.2 and 12 of LiCl solutions, respectively) among reported advanced adsorbents. 90 % of Li + is desorbed within 60 min, indicating the efficient and rapid Li + desorption response of the hydrogel. Meanwhile, this hydrogel still maintains a Li + adsorption capacity of 90 % after eight adsorption-desorption cycles, during which Ti loss is <0.42 % in each cycle. In this work, HTO-PVA/PAAm hydrogel synthesized by an environmentally friendly and low-cost approach shows great application potential as a new strategy for Li + adsorption from liquid resources.
Yan Cheng,Feng Feng,Tianxue Zhu,Yanhui Zheng,Yukui Gou,Dapeng Yang,Jianying Huang,Yuekun Lai,Zhongyi Jiang
In recent years, the demand for transparent substrates (e.g. windows, mirrors and photovoltaic glass) with anti-fogging performances has increased, while conventional anti-fogging coatings, like single-component organic coatings (PVA, PAA, PAAm), show poor stability and cannot maintain their performance stably under harsh environments. In this work, KH570@TiO 2 plays the role of a bottom layer (KT coating) to increase roughness and binding, where the hydrolysis of KH570 anchors the substrate and provides active sites for the binding of the top coating, and the addition of the TiO 2 enhances UV shielding properties. A composite PVA-AAm-POSS-NH 2 gel (PAP coating) served as the top layer, which contains a large number of hydrophilic groups and thus endow the composite coating with satisfactory anti-fogging performance. The strong bonding force provided by the KT coating and the tight physical entanglement of the PAP coating endow the double-layer coating (PAPKT coating) stable anti-fogging performance (60 times of tape peeling test, 100 times of sandpaper friction test, and sand-punching test), and 48 s icing delay performance. The multi-performances make this work great potential in automotive glass as well as building facades to cope with complex situations.