Fig. 3. Dynamical study of photoresins by optical microscopy.
a Constructed images obtained from movies of islands of polymer formed when resin/crosslinker inside a capillary is exposed to a focused 405 nm laser spot. A slice through the center of the island reveals its two opposite edges and is plotted as function of time. Two examples (i) and (ii) are shown for 15 wt. % DA-170 and 99 wt .% DA-700. b Delay time, td, extracted from a fit to Eq. 1 (See Experimental Section) as a function of wt. % crosslinker. c Weight % of Ag extracted from SEM/EDS analysis at the surface of the cylinder as a function of td for various resin formulations. The delay times are from the same gelation experiments exposed to a 405 nm laser in part a, b for each formulation.