title: Electrowetting of nitro-functionalized oligoarylene thiols self-assembled on polycrystalline gold.
abstract: Four linear terarylene molecules (i) 4-nitro-terphenyl-4″-methanethiol (NTM), (ii) 4-nitro-terphenyl-3″,5″-dimethanethiol (NTD), (iii) ([1,1';4',1″] terphenyl-3,5-diyl)methanethiol (TM), and (iv) ([1,1';4',1″] terphenyl-3,5-diyl)dimethanethiol (TD) have been synthesized and their self-assembled monolayers (SAMs) have been obtained on polycrystalline gold. NTM and NTD SAMs have been characterized by X-ray photoelectron spectroscopy, Kelvin probe measurements, electrochemistry, and contact angle measurements. The terminal nitro group (-NO2) is irreversibly reduced to hydroxylamine (-NHOH), which can be reversibly turned into nitroso group (-NO). The direct comparison between NTM/NTD and TM/TD SAMs unambiguously shows the crucial influence of the nitro group on electrowetting properties of polycrystalline Au. The higher grade of surface tension related to NHOH has been successfully exploited for basic operations of digital μ-fluidics, such as droplets motion and merging.
authors: Università degli Studi di Modena e Reggio Emilia , Dipartimento di Scienze della Vita, via Campi 183, I-41125 Modena, Italy.
authors: Stefano
authors: S
authors: Casalini
authors: Marcello
authors: M
authors: Berto
authors: Carlo A
authors: CA
authors: Bortolotti
authors: Giulia
authors: G
authors: Foschi
authors: Alessandra
authors: A
authors: Operamolla
authors: Michele
authors: M
authors: Di Lauro
authors: Omar Hassan
authors: OH
authors: Omar
authors: Andrea
authors: A
authors: Liscio
authors: Luca
authors: L
authors: Pasquali
authors: Monica
authors: M
authors: Montecchi
authors: Gianluca M
authors: GM
authors: Farinola
authors: Marco
authors: M
authors: Borsari
keywords: conjugated thiols; electrochemistry; electrowetting on dielectrics; micro-electromechanical systems; nitro-terminated self-assembled monolayers