Haoru Shan,Wenqiang Wang,Zhirong Wang,Jianlong Ge,Qixia Liu,Wei Zhang,Qiuxia Fu
Constructing CuO-based nanofibrous membranes with remarkable mechanical performance, controllable nanostructures, and outstanding catalytic oxidation activity would be conducive to decomposing organic contaminants in wastewater through advanced oxidation processes; however, there remains a huge shortfall of such ceramic membranes that they are usually fragile with poor deformability. Herein, a universal approach was proposed for fabricating flexible CuO nanoparticles-anchored ZrO 2 nanofibrous membranes (CZNMs), that is, through the combination of successive ionic layer adsorption and reaction (SILAR) assembly and the follow-up thermal oxidation processes. Notably, the developed preparation method exhibited strong expansibility, which could be extended to the synthesis of other flexible metal oxides/ceramic nanofibrous composites, such as ZnO/ZrO 2 , CdO/ZrO 2 , and Mn 3 O 4 /ZrO 2 . Profiting from the integrated advantages of superior catalytic reactivity, uniform nanostructures distribution, and excellent mechanical properties, the resultant CZNMs displayed a prominent degradation efficiency of 92.4% within 50 min towards tetracycline hydrochloride under the activation of peroxymonosulfate (PMS). Furthermore, the stable hierarchical structures and robust mechanical performance endow the as-synthesized membranes with extraordinary reusability and easy recycling. The successful preparation of such ceramic-based nanofibrous membranes with superior flexibility and high-efficient catalytic performance might provide some reference to develop other synergetic membranous catalysts for wastewater treatment.
Developing ceramic materials for thermal insulation is vital for various applications. However, ceramics have been considered intrinsically rigid and brittle due to the limited crystallographic slips and structural collapse during service. Their lack of flexibility has hampered many high-end applications of ceramic materials. We developed flexible Al2O3/ZrO2 nanofibrous membranes via sol–gel electrospinning and calcination. Al2O3/ZrO2 nanofibrous membranes had flexibility from −196 °C to 1300 °C and low thermal conductivity (∼0.03166 W m−1 K−1 at room temperature). They also supported 1350-times their weight without suffering structual damage. Hence, Al2O3/ZrO2 nanofibrous membranes could be used for thermal insulation in aerospace and industrial fields, and even in harsh environments.
Weidong Han,Bin Ding,Mira Park,Fuhai Cui,Su-Hyeong Chae,Hak-Yong Kim
Poly(vinyl pyrrolidone) (PVP)/La 3+ /Zr 4+ precursor nanofibrous membranes (LZPNM) with various Zr contents were synthesized via a simple electrospinning method. By controlling the Zr incorporation, the tensile properties of precursor membranes dramatically change from 0.77 to 1.73 MPa. Meanwhile, the average diameters of precursor nanofibers increase with the increase of Zr contents (from 283 to 535 nm). In addition, flexible La 2 O 3 -ZrO 2 nanofibrous membranes (LZNM) were obtained by calcination of corresponding precursor membranes. Furthermore, the structures and morphologies of the precursor membranes were investigated using X-ray powder diffraction analysis (XRD) and field-emission scanning electron microscopy (FE-SEM). The surface functional groups and thermal properties of the precursor membranes were measured via Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA).