Surfaces and Interfaces of Liquid Metal Core–Shell Nanoparticles under the Microscope. (15th April 2020)

• Record Type: Journal Article
• Authors: Hafiz, Sabrina S.; Labadini, Daniela; Riddell, Ryan; Wolff, Erich P.; Xavierselvan, Marvin; Huttunen, Paul K.; Mallidi, Srivalleesha; Foster, Michelle
• Is Part Of: Particle and particle systems characterization. Volume 37:Number 5(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-15
• Subjects: eutectic gallium indium -- ligand–nanoparticle interface -- liquid metal core–shell nanoparticles; Particles -- Periodicals; 620.43
• DOI: 10.1002/ppsc.201900469
• Languages: English
• ISSNs: 0934-0866

Abstract

Abstract: Eutectic gallium indium (EGaIn), a Ga‐based liquid metal alloy holds great promise for designing next‐generation core–shell nanoparticles (CSNs). A shearing‐assisted ligand‐stabilization method has shown promise as a synthetic method for these CSNs; however, determining the role of the ligand on stabilization demands an understanding of the surface chemistry of the ligand–nanoparticle interface. EGaIn CSNs are created and functionalized with aliphatic carboxylates of different chain length, allowing a fundamental investigation on ligand stabilization of EGaIn CSNs. Raman and diffuse reflectance Fourier transform spectroscopies (DRIFTS) confirm reaction of the ligand with the oxide shell of the EGaIn nanoparticles. Changing the length of the alkyl chain in the aliphatic carboxylates (C2–C18) may influence the size and structural stability of EGaIn CSNs, which is easily monitored using atomic force microscopy (AFM). No matter how large the carboxylate ligand, there is no obvious effect on the size of the EGaIn CSNs, except the particle size getting more uniform when coated with longer chain carboxylates. The AFM force–distance measurements are used to measure the stiffness of the carboxylate‐coated EGaIn CSNs. In corroboration with DRIFTS analysis, the stiffness studies show that the alkyl chains undergo conformational changes upon compression. Abstract : Eutectic gallium indium liquid metal nanoparticles are created in solutions of n ‐alkane fatty acids resulting in core–shell nanoparticles (CSNs) coated in carboxylates of varying alkyl chain length. Atomic force microscopy and vibrational spectroscopies (DRIFTS, Raman) reveal that changing the chain length of the carboxylate ligand has an effect on the size, stability, and robustness of the CSNs.