Preparation of Janus microfibers with magnetic and fluorescence functionality via conjugate electro-spinning

Highlights: • High-yielding rate of Janus microfibers in the product is designed and actualized via conjugate electrospinning. • Magnetism and fluorescence are highly integrated into a single Janus microfiber. • Adverse influence of magnetic material on fluorescent material is greatly reduced. • Fabrication technique can be popularized to obtain other Janus multifunctional materials. -- Abstract: In order to achieve high-yielding rate of Janus microfibers in electrospun product, conjugate electrospinning is employed via optimization of electrospinning conditions. Further, Janus microfibers array affording dual-functional performance of magnetism and fluorescence is fabricated by above technique. The unique structure has the advantage of realizing complete separation of fluorescent materials from magnetic nanoparticles, which can ensure high fluorescent intensity without remarkably adverse effect of magnetic substance. The diameter of the fibers in the array is 11.72 ± 0.09 μm. The emission peaks of Tb³⁺ are found and assigned to the transitions of ⁵D₄ → ⁷F₆ (490 nm), ⁵D₄ → ⁷F₅ (545 nm), ⁵D₄ → ⁷F₄ (581 nm) and ⁵D₄ → ⁷F₃ (620 nm). Compared with the counterpart contrastive samples, Janus microfibers array present higher comprehensive performance owing to the exceptional structure and directionally ordered arrangement. Moreover, the saturation magnetization can be tailored from 3.6 emu·g⁻¹ to 24.0 emu·g⁻¹ via adding various amounts of Fe₃O₄ NPs. This work provides an effective method to fabricate other advanced multifunctional materials.