Electronic Supporting Information Tailoring the wetting properties of thiolene microfluidic materials Simone Silvestrini, Davide Ferraro, Tamara Tóth, Matteo Pierno, Tommaso Carofiglio, Giampaolo Mistura and Michele Maggini. Corresponding author: M. Maggini; Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy. Tel: +39 0498275662. E-mail: michele.maggini@unipd.it S1 – Preparation of NOA81 surfaces by spin coating S2 – ATR-IR spectra of surfaces modified with NOA81 S3 – Fabrication of a demonstrator device S4 – Movie of a demonstrator device S1 – Preparation of NOA81 surfaces by spin coating The single component, liquid NOA81 resin (stored at 4 °C) was warmed to room temperature for 15 minutes before use. Then it was spin-coated on 3’’ x 1’’ glass microscope slides as a neat, pure liquid. The glass slide was accelerated in 5 s to 300 rpm, kept at that rate for 15 s, then further accelerated to 3000 rpm in 5 s and allowed to spin for 60 s before being stopped in 10 s. Coated slides were then exposed for 30 min to UV irradiation at 365 nm using a 150 W lamp. The UV curing was followed by thermal annealing at 50 °C overnight on a conventional heating plate. S2 – ATR-IR spectra of surface modified NOA81 powders A slab of cured NOA81 resin was pulverized and part of the powder was added to a round bottom flask filled with a 5% v/v toluene solution of octadecyltrichlorosilane (OTS), then stirred at room temperature for 15 minutes. The powder was transferred on filter paper, where it was washed thoroughly with toluene in order to remove all traces of unreacted chlorosilanes. It was then further washed with isopropanol and dried under anitrogen flow. ATR-IR spectra of both the untreated powder and its OTS-functionalized counterpart were collected on a Nicolet 5800 spectrometer equipped with a Smart Performer ATR accessory (figure 1). Figure S1. ATR-IR spectra for unfunctionalized (black) and OTS-functionalized (red) NOA81 resin. The bands highlighted by arrows can be ascribed to the asymmetric C-H bonds stretching in the octadecyl chain (at 2959 cm -1 for CH 3 and 2853 cm -1 for CH 2 ). Wavenumbers (cm -1 ) Electronic Supplementary Material (ESI) for Lab on a Chip This journal is © The Royal Society of Chemistry 2012