Synthesis of poly(styrene-N-hydroxymethyl acrylamide) microspheres and their application in patterned photonic crystals

In order to achieve bright and durable structural colors, the poly(styrene-N-hydroxymethyl acrylamide) nanospheres with self-crosslinking property were used as structural units to construct patterned photonic crystals. In this article, we thoroughly explore the effect of synthesis factors on particle sizes and monodispersity of poly(styrene-N-hydroxymethyl acrylamide) nanospheres, with the characterization of the performance of prepared poly(styrene-N-hydroxymethyl acrylamide) nanospheres. Then the color effects and durability of structural colors produced from poly(styrene-N-hydroxymethyl acrylamide) photonic crystals were characterized and evaluated. The results showed that the monodisperse poly(styrene-N-hydroxymethyl acrylamide) nanospheres with particle sizes ranging between about 200∼320 nm could be synthesized. The prepared poly(styrene-N-hydroxymethyl acrylamide) nanospheres exhibit typical core-shell structure, in which the hydrophobic polystyrene domain is mainly located on the core, and there is a thin shell mainly rich in hydrophilic Poly(N-hydroxymethyl acrylamide) covering the polystyrene core. Moreover, the poly(styrene-N-hydroxymethyl acrylamide) nanospheres have self-crosslinking properties, which could be confirmed by the thermogravimetric curve. Furthermore, the photonic crystals constructed by prepared poly(styrene-N-hydroxymethyl acrylamide) nanospheres still present vivid and durable structural colors after friction, bending, washing and soaking tests. Specifically, the patterned photonic crystals can be constructed on photo paper, plastic board and fabrics, and the resultant structural colors present significantly iridescent effects. The research results can provide strategic support for the practical application of photonic crystals with structural colors.