Low voltage electrowetting of non-aqueous fluorescent quantum dot nanofluids

• Published in: Journal of molecular liquids Vol. 359; p. 119086
• Main Authors: Tohgha, Urice N., Watson, Alexander M., Godman, Nicholas P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2022
• Subjects: Contact angle; Electrowetting; Fluorescent QDs; Non-aqueous; QD nanofluids; Voltage; PPA; NP; DMSO; γll, m; θLY; QD nanofluids; kV; γsa; QD; V; Voltage; Electrowetting; rms; DMF; Non-aqueous; CA; d; Δθ; γla; EWOD; sat; TBAB; Contact angle; Fluorescent QDs; Hz; ε; µ; γls; S.T; θ0; γll, c
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2022.119086

[Display omitted] •Low voltage electrowetting of diverse non-aqueous quantum dot (QD) nanofluids.•Enhanced wettability from QD ligand and nanoparticle effects.•Preservation of QD fluorescent properties in non-aqueous electrowetting platform.•QD nanofluid optical and electrowetting properties are appealing for droplet-driven display applications. We present electrowetting studies of diverse non-aqueous CdSe quantum dot (QD) nanofluids with desirable optical properties for electrowetting and electrofluidic display applications. The QD-nanofluids investigated herein include QD-2.9 (CdSe/ZnS: average size 2.9 nm), QD-18 (CdSe/CdS: 2.9 nm core with thick gradient shell for average size 18 nm), and QD-T (CdSe/ZnS tetrapods: 4.7 nm and 3.5 nm average arm length and width respectively). Low voltage and reversible droplet wettability was achieved while maintaining the fluorescent properties of QD nanofluids in both dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Maximum contact angle (CA) change with minimal voltage application (Δθ10V = 78 ± 3) was achieved for QD-T and QD-2.9 DMF-based nanofluids which is desired for practical applications. Conversely, there was comparable wettability of QD-18 nanofluids in DMF and DMSO, stemming from QD size effects. The robust electrowetting of non-aqueous QD nanofluids has important implications for droplet-driven display and digital microfluidic applications.