Magnetically induced demulsification of water and castor oil dispersions stabilized by Fe3O4-coated cellulose nanocrystals
Magnetically induced demulsification of water and castor oil dispersions stabilized by Fe3O4-coated cellulose nanocrystals
复制标题
DOI：
10.1007/s10570-021-03813-x
复制
发表时间：
2021-03-21
期刊：
影响因子：
5.7
通讯作者：
Urena-Benavides, Esteban E.
中科院分区：
文献类型：
--
作者：
Hasan, Mohammad J.;Petrie, Frankie A.;Urena-Benavides, Esteban E.
合成了超顺磁性氧化铁（Fe3O4）纳米粒子（NP）包覆的纤维素纳米晶体（CNC）并用于制备具有磁控稳定性的乳液。通过一步共沉淀法将磁铁矿纳米粒子沉积到木浆 CNCs (WCNCs) 和细菌 CNCs (BCNCs) 的表面。 CNC 与 Fe3O4 质量比（1:1、1:2 和 1:4）的影响各不相同，以优化杂化纳米粒子的胶体、磁性和乳化性能。 TEM 图像显示，与较低的 Fe3O4 负载量（1:1 和 1:2）相比，1:4 的比率导致 Fe3O4 的覆盖范围更大。 CNC 和 Fe3O4 似乎通过两个颗粒表面上的羟基之间的氢键相互作用。杂化纳米粒子的饱和磁化强度很高，WCNC/Fe3O4 (1:4) 为 56 emu/g，BCNC/Fe3O4 (1:4) 为 60 emu/g。此外，它们还是蓖麻油和水乳液的有效稳定剂。磁铁矿降低了 CNC 的胶体稳定性，同时提供超顺磁性，从而使皮克林乳液稳定，并随后通过外部磁铁消除皮克林效应。油包水乳液（含油量为 70% 和 90% V/V）被外部磁铁破坏，同时 CNC/ Fe3O4 纳米颗粒被回收和循环利用。 30％和50％V/V油乳液是水包油的并且不能被磁体破坏，这可能是由于乳液稳定性较高。制造的磁性 CNC 在磁驱动分离、药物输送和石油回收方面具有潜在用途。图文摘要
Superparamagnetic iron oxide (Fe3O4) nanoparticle (NP) coated cellulose nanocrystals (CNCs) were synthesized and used to prepare emulsions with magnetically controlled stability. Magnetite NPs were deposited onto the surface of wood pulp CNCs (WCNCs) and bacterial CNCs (BCNCs) by a one-step coprecipitation method. The effect of the CNC to Fe3O4 mass ratio (1:1, 1:2, and 1:4) was varied to optimize the colloidal, magnetic and emulsifying properties of the hybrid NPs. TEM images showed that the 1:4 ratios lead to greater coverage of Fe3O4 than lower Fe3O4 loadings (1:1, and 1:2). The CNCs and Fe3O4 appeared to interact via hydrogen bonding between the hydroxyl groups on the surfaces of both particles. The hybrid NPs had high saturation magnetizations of 56 emu/g for WCNC/Fe3O4 (1:4) and 60 emu/g for BCNC/Fe3O4 (1:4). In addition, they were efficient stabilizers for castor oil and water emulsions. The magnetite lowered the colloidal stability of the CNCs while providing superparamagnetic properties which allowed stabilization of Pickering emulsions and the subsequent depletion of the Pickering effect by an external magnet. Water-in-oil emulsions, with oil contents of 70% and 90% V/V, were broken by an external magnet, while the CNC/ Fe3O4 NPs were recovered and recycled. The 30% and 50% V/V oil emulsions were oil-in-water and could not be broken by the magnet, probably due to higher emulsion stability. The fabricated magnetic CNCs have potential use in magnetically driven separations, drug delivery, and oil recovery. Graphic abstract