Ordered Alternating Binary Polymer Nanodroplet Array by Sequential Spin Dewetting

Abstract

We report a facile technique for fabricating an ordered array of nearly equal-sized mesoscale polymer droplets of two constituent polymers (polystyrene, PS and poly(methyl methacrylate), PMMA) arranged in an alternating manner on a topographically patterned substrate. The self-organized array of binary polymers is realized by sequential spin dewetting. First, a dilute solution of PMMA is spin-dewetted on a patterned substrate, resulting in an array of isolated PMMA droplets arranged along the substrate grooves due to self-organization during spin coating itself. The sample is then silanized with octadecyltrichlorosilane (OTS), and subsequently, a dilute solution of PS is spin-coated on to it, which also undergoes spin dewetting. The spin-dewetted PS drops having a size nearly equal to the pre-existing PMMA droplets position themselves between two adjacent PMMA drops under appropriate conditions, forming an alternating binary polymer droplet array. The alternating array formation takes place for a narrow range of solution concentration for both the polymers and depends on the geometry of the substrate. The size of the droplets depends on the extent of confinement, and droplets as small as 100 nm can be obtained by this method, on a suitable template. The findings open up the possibility of creating novel surfaces having ordered multimaterial domains with a potential multifunctional capability.

Dewetting of a pre-patterned thin polymer bilayer: influence of the instability mode

“…[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] The template-directed and template-assisted dewetting of the thin polymer bilayer have been investigated extensively due to their technological and scientic importance. [31][32][33][34][35] Mukherjee et al 32,33 reported the dewetting process of a thin bilayer of polystyrene and poly(methylmethacrylate) on a topographically patterned nonwettable substrate, and using this method they fabricate many different structures.…”

“…Previous studies [10][11][12][13][14][31][32][33][34][35] on the template-directed or template-assisted dewetting of the thin polymer lms mainly focus on the inuence of the geometry and size of the template pattern on the dewetting structures. In this paper, we concentrate on the inuence of instability mode on the templateassisted dewetting process of the thin polymer bilayer.…”

Synergism of Dewetting and Self-Wrinkling To Create Two-Dimensional Ordered Arrays of Functional Microspheres

“…Thus, in the past decades, enormous experimental and theoretical endeavors have been made to improve the ordering degree of the dewetting-induced features. 9−12,14−28 Previously, three preferred strategies have been introduced for directing dewetting: chemically 14,15 or topographically patterned substrates [9][10][11][20][21][22][23][24][25]28 or externally structured templates. 16 −19 In the above directed dewetting, lithography-based techniques such as photolithography or e-beam etching have been directly or indirectly involved in the fabrication of the required patterned substrates and structured templates.…”

Liquid–liquid interfacial slip induced layer instability in a thin polymer bilayer

“…Thin polymer film can become unstable and spontaneously rupture whenever the intermolecular disjoining pressure increases with increased film thickness [6][7][8][9][10][11][12][13][14][15][16][17] . The dewetting of thin polymer film progresses with the formation and growth of randomly placed holes with a certain mean length scale.…”