Anisotropically structured magnetic aerogel monoliths

Abstract

Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture.

3D Self‐Supporting Porous Magnetic Assemblies for Water Remediation and Beyond

“…[126] In the second place, the in-field synthesis provided a unique way to modulate structures in 3D-SPMAs, which is feasible to create certain distinctive materials. [36,37] For example, Gish et al fabricated the silica composite aerogels containing Nd 2 Fe 14 B particles in the presence of magnetic field (Figure 9d). The resultant materials showed pronounced optically anisotropy due to the alignment of magnetic particles in the field during gelation.…”

“…[36,37] Gich et al [36] fabricated magnetic silica composite aerogels (Figure 9d) by conducting reaction in an 8000 Oe homogeneous magnetic field. The magnetic Nd 2 Fe 14 B particles showed a needle-like arrangement in the gel, which is induced by the alignment of magnetic particles along the direction of magnetic field during the gelation of silica.…”

“…Moreover, 3D-SPMAs can also acquire certain novel properties or functions, such as magnetic field induced structures modulation and magnetic shape memory effects. [35][36][37] In past few years, a number of 3D-SPMAs based on commercial foams/sponges, [33,34,[38][39][40] carbon material aerogels, [41][42][43] polymers aerogels, [44,45] and hydrogels [46][47][48][49][50] have been fabricated, showing great promise in water remediation and other applications. These 3D-SPMAs are constructed by either bottom-up assembly of magnetic building blocks or modifying as-existing 3D nonmagnetic networks with magnetic materials.…”

Multiscale Nanoparticle Assembly: From Particulate Precise Manufacturing to Colloidal Processing

“…[15a] Even after 500 LbL deposition cycles the film is just 2 µm thick (Figure 10a, left). [102] However, the most fascinating aspect of using nanoparticle dispersions rather than molecular precursors for the preparation of aerogels is the possibility to combine different types of nanoparticles within the same monolith. The most surprising aspect of these films is that they could be stretched up to 110% without losing their electrical conductivity.…”

Nonaqueous synthesis of Ag-functionalized In2O3/ZnO nanocomposites for highly sensitive formaldehyde sensor

“…As reported, the IZO structure are constructed by metal organic chemical vapor deposition (MOCVD) [7], electrospinning [2], thermal vapor method [8], etc.. Also, the development of a new route to synthesize IZO nanocomposites for gas sensors is of primary importance in scientific research and industrial applications. Over the past decades, the nonaqueous synthesis was successfully applied for the synthesis of various metal oxide nanoparticles [9,10], hybrid nanomaterials [11], aerogel [12,13], and also for the growth of metal thin films [14,15], in which involves the reaction of a metal halide with an oxygen Page 4 of 34 A c c e p t e d M a n u s c r i p t donor such as an alkoxide, an ether, an alcohol, and so on under nonaqueous conditions, leading to the formation of an inorganic oxide with a common byproduct of alkyl halide. In particular the synthesis of In 2 O 3 [16][17][18] and ZnO [19] by the nonaqueous synthesis were reported to be quite robust.…”