Laser-induced fragmentation of carbonyl iron as a clean method to enhance magnetorheological effect

• Published in: Journal of cleaner production 2020-05, Vol.254, p.120182, Article 120182
• Main Authors: Cvek, Martin, Torres-Mendieta, Rafael, Havelka, Ondrej, Urbanek, Michal, Plachy, Tomas, Cernik, Miroslav
• Format: Article
• Language: English
• Subjects: Additive; Laser fragmentation in liquids; Magnetism; Magnetorheology; Nanoparticle fabrication; Suspension
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2020.120182

Magnetic nanoparticles (NPs) are widely used as additives in magnetorheological (MR) suspensions to enhance their magnetic performance and kinetic stability. The synthesis of NPs is often resolved via chemical routes or complex manufacturing procedures, which require hazardous chemicals and generate waste products. In this study, a clean, laser-mediated strategy known as laser fragmentation in liquids (LFL) is proposed that enables the synthesis of NP-based additives directly from the given MR suspension, with the added advantage of limiting the production of waste during the fabrication process. The carbonyl iron (CI) microparticles dispersed in ethylene glycol were used as both the MR suspension and precursor agent in the production of the nanoscale additive. The size and crystalline structure of the NPs were investigated via TEM and XRD, respectively. The mixture of the MR suspension and laser-synthesized additive notably facilitated the magnetisation of the CI particles, incrementing the MR characteristics and dynamic yield stress values by up to 31% in a low-to-moderate field region, which are important aspects in various field-controlled robotic, damping and torque systems. The concept presented appears to be an effective and clean alternative for fabricating bidispersed MR suspensions through the nanoscale additive approach. [Display omitted] •Magnetorheological (MR) suspensions are enhanced using a nanoparticle (NP) additive.•The NP additive is synthesized from the MR suspension without producing any waste.•MR performance is enhanced in low-to-moderate magnetic field region.•Laser-induced NP production constitutes a clean option for improving smart fluids.