Fig. 2From: Surface Functionalized Nanofibrillar Cellulose (NFC) Film as a Platform for Immunoassays and DiagnosticsThe effect of TEMPO-mediated oxidation on contact angle (blue line) and total charge (green line) of NFC films as a function of the oxidation time. Contact angles were obtained after 10 s recording. The lines are not fitted, but just added as aid to the eyes. Spreading out of the water droplet was noted to occur at contact angles below 15°Back to article page