Fabrication of micropatterns with dyes in polymer films by selective doping of dye vapor in a vacuum

Abstract

In this article a novel process for patterning of dye into a positive-type novolac resin is reported by doping vapor of the blue dye, Solvent Blue 59 (SB59), using a simple vacuum process named the vapor transportation method. SB59-doped novolac resin films were examined by UV-vis absorption spectroscopy and optical microscopy. When SB59 vapor was doped into unexposed films at temperatures above 1308C, absorption peaks due to SB59 were detected. In contrast, no absorption peaks were detected when SB59 vapor was doped into exposed films. These results indicated the selective doping of SB59 vapor into unexposed novolac resin films. When SB59 vapor reached the surfaces of micropatterned novolac resin films with both unexposed and exposed areas, SB59 was doped selectively into the unexposed areas of the films, resulting in the production of micropatterns with SB59 molecules in the patterned films.

Toward a New Generation of Smart Biomimetic Actuators for Architecture

“…A strategy recently developed by Rühe and coworkers is to use for at least one of the layers a precursor copolymer, which can be thermally or photochemically activated (Figure b) . During this activation process reactive intermediates are formed such as biradicaloid triplet states through the activation of ketones, nitrenes, or carbenes, which can crosslink the system through CH insertion reactions. Groups which are coincidentally located directly at the surface can link also the dissimilar polymer chains together, thereby covalently linking one layer to next.…”

Novel fabrication of nano-pattern with optical function by selective doping of dye vapor into novolac resin

“…Previously, we reported the selective doping of polystyrene (PS) nanophase-separated structures of a diblock copolymer with a photochromic dye [10,11] using a simple vacuum process, named the vapor transportation method [7,[10][11][12][13][14][15][16]. This is an efficient method for selective doping of individual photochromic molecules into self-organized PS nano-structures [12] and for addition of the photochromic property selectively into them [10,11].…”

“…However, there are several self-organized structures in diblock copolymers, resulting in limitation of pattern design. Then, we also presented a technique describing the fabrication of dye-containing patterns by selective doping of the Solvent Blue 59 (SB59: blue dye) [15] and 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)4H-pyran (DCM; fluorescent dye) [16] into unexposed areas of "patterned" novolac resin films. This procedure can dope the dyes into the micro-patterned areas designed freely without masks, extending the application of our method.…”

Surface‐attached polymer networks through carbene intermediates generated from α‐diazo esters

“…Another simple and versatile method, which has been recently introduced, is to synthesize a copolymer with functional groups, which form reactive intermediates upon activation, which then in turn induce a reaction with neighboring polymer chains. Examples for such reactive intermediates are ketyl radicals formed through irradiation of benzophenones and nitrenes formed upon the activation of azides . In both cases, crosslinking proceeds via multiple formal C—H‐insertions: depending on the type of the activatable group, the formation of the reactive intermediate can be induced via a photochemical or thermal reaction.…”

“…The elimination of nitrogen in alkyl diazo compounds is facilitated through electron donating groups and attenuated by mesomeric stabilization and electron withdrawing substituents such as aromatic rings or esters neighboring to the diazo group . After formation of the carbenes, they either undergo Wolff‐rearrangement to the corresponding ketenes or react with adjacent X—H (X = C, S, O, N) bonds through an insertion reaction . The ketenes obtained through Wolff‐rearrangement can now themselves react in C—H insertion reactions or undergo side reactions, for example, through oxidative processes.…”