High performance stainless steel-ceramic composite hollow fibres for microfiltration
High performance stainless steel-ceramic composite hollow fibres for microfiltration
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DOI：
10.1016/j.memsci.2017.07.017
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发表时间：
2017-11-01
影响因子：
9.5
通讯作者：
Li, Kang
中科院分区：
文献类型：
--
作者：
Chong, Jeng Yi;Wang, Bo;Li, Kang
不锈钢（SS）由于其优异的机械强度和耐化学性而成为用于膜应用的有吸引力的材料。与陶瓷等无机材料相比，SS具有高度柔性和坚韧，易于在工业规模上处理。采用相转化烧结技术可以制备多孔不锈钢中空纤维。虽然烧结条件已得到充分研究，但在实现SS中空纤维更小孔径方面的成功仍然有限，限制了其实际应用。在我们的研究中，我们引入陶瓷纳米颗粒来填充SS颗粒周围的大孔隙。采用相转化辅助共挤出技术一步制备双层SS/SS陶瓷中空纤维。外层是SS和氧化钇稳定的氧化锆（YSZ）的混合物，形成具有小孔径的分离层。内层由SS组成，其为中空纤维提供强机械强度。复合中空纤维膜的平均孔径可以减小到约300 nm，比单层SS中空纤维的孔径小得多，单层SS中空纤维的孔径通常大于1 μ m。与纯陶瓷中空纤维相比，双层SS/SS-YSZ中空纤维膜具有更高的机械强度，也是高度多孔的，纯水通量可高达3000 LMH bar（-1），使其在增值产品的微过滤中具有吸引力。
Stainless steel (SS) is an attractive material for membrane applications due to its excellent mechanical strength and chemical resistance. Compared to inorganic materials such as ceramic, SS is highly flexible and tough, and is easy to handle at an industrial scale. Porous stainless steel hollow fibres can be fabricated by using the phase-inversion and sintering technique. While the sintering conditions have been well studied, success in achieving smaller pore size of SS hollow fibres remains limited, constraining their practical applications. In our study, we introduce ceramic nanoparticles to fill up the large pores around SS particles. A phase-inversion assisted co-extrusion technique has been used to fabricate dual-layer SS/SS-ceramic hollow fibres in one step. The outer layer is a mixture of SS and yttria-stabilized zirconia (YSZ), creating a separating layer with small pore sizes. The inner layer consists of SS, which provides a strong mechanical strength to the hollow fibres. The mean pore size of the composite hollow fibre membranes can be reduced to approximately 300 nm, much smaller than the pore size of single-layer SS hollow fibres, which is generally larger than 1 mu m. With improved mechanical strength compared to pure ceramic hollow fibres, the dual-layer SS/SS-YSZ hollow fibre membranes are also highly porous and the pure water flux can reach as high as similar to 3000 LMH bar(-1), making them attractive in microfiltration for value-added products.