Fluorescent Microscopy Proving Resin Adhesion to a Fluorinated Mold Surface Suppressed by Pentafluoropropane in Step-and-Repeat Ultraviolet Nanoimprinting

Abstract

Resin adsorption on fluorinated silica mold surfaces during step-and-repeat ultraviolet nanoimprinting was studied by fluorescent microscopy using a fluorescent UV-curable resist. The fluorescence intensity indicating resin adsorption to the mold surfaces in step-and-repeat UV nanoimprinting under air atmosphere was significantly higher than that under condensable gas pentafluoropropane (PFP) atmosphere. The larger resin adsorption in air was attributable to sticking uncured resin around trapped air bubbles preventing the UV-curable resist from causing acrylate radical photopolymerization and to the small amount of resin components adhering to the mold surface. The entire adsorption of resin components, not only a fluorescent dye doped in a UV-curable resin, was confirmed by high-sensitivity UV–visible absorption spectroscopy and atomic force microscopy in a frictional mode. PFP suppressed obviously stuck uncured resin and entirely adhered resin components to the fluorinated mold surface. The entire adsorption of resin components was compared among three kinds of fluorinated mold surface treated with commercially available antisticking reagents, FAS13 (tridecafluoro-1,1,2,2-tetrahydro-octyltrimethoxysilane), OPTOOL DSX, and OPTOOL AES4-E. It was proved by the fluorescent microscopy that the fluorinated mold surface prepared by chemical vapor surface modification with FAS13 showed the best antisticking property among the fluorinated mold surfaces, because the entire adsorption of resin components was hardly affected by the number of cycles of step-and-repeat UV nanoimprinting and by the positions in the mold surface.

Electric Field Tunability of Photoluminescence from a Hybrid Peptide–Plasmonic Metal Microfabricated Chip

“… 20 A number of techniques have been used to make PEF emission substrates, including top-down lithographic methods including e-beam lithography, 10 , 14 , 21 colloidal lithography, 22 vacuum evaporation, 23 and nanoimprinting. 24 These techniques generally have a limitation, either high cost or lack of reproducibility or sensitivity. Bottom-up fabrication methods based on self-assembly, however, have proved to be a reproducible, highly sensitive method for PEF substrate fabrication.…”

“…It is generally accepted that PEF emission occurs from local electromagnetic field enhancement or increased quantum yield, allied with a rise in the radiative decay rate. , The interaction between the fluorophore and a metallic surface can result in the reduction of fluorescence when the fluorophore is separated from the metal surface by less than a few nanometers, ,− and yet enhanced fluorescence has also been observed for fluorophores in contact with silver nanoparticles (AgNPs) . A number of techniques have been used to make PEF emission substrates, including top-down lithographic methods including e-beam lithography, ,, colloidal lithography, vacuum evaporation, and nanoimprinting . These techniques generally have a limitation, either high cost or lack of reproducibility or sensitivity.…”

Investigation of nonreactive fluoroalkyl-containing surfactants for reducing release energy of ultraviolet-cured acrylate resins

“…% 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (Irgacure 907; photoinitiator). 11 The base resin was used as a surfactant-free UV-curable resin causing radical photopolymerization. Fluoroalkyl-containing surfactants were used as additives, and the chemical structures and abbreviations are summarized in Table I.…”

“…After drying by blowing nitrogen gas, the silica surface was cleaned by exposure to UV/ozone for 20 min using a UV/ozone cleaner (Sen Lights PL16-110). The cleaned silica surface was subjected to CVSM with FAS13 at 150 C for 1 h. 11 The silica lens used in the mechanical measurement could be used again after the above procedure as well as an unused silica lens. To form a reactive adhesion layer, the surface of an 8-in.…”

Solubility Property of Condensable Gases of Trans-1-Chloro-3,3,3-Trifluoropropene and Trans-1,3,3,3-Tetrafluoropropene in UV Nanoimprint

“…In the case of PFP, the liquid volume is 1/200th of the gas volume. Ambient PFP is not only a potential means of achieving quick and bubble-free cavity filling [9], but also has beneficial effects, such as decreases the viscosity of the UV-curable resin [10], decreases the amount of resin sticking to the mold during demolding [11], and reduces the demolding force to approximately one-third of that in the case of air [12]. However, there are also some drawbacks, such as the relatively large shrinkage of 22% (cf.…”