TY - JOUR

T1 - Reshapable bio-based thiol-ene vitrimers for nanoimprint lithography

T2 - Advanced covalent adaptability for tunable surface properties

AU - Sölle, Bernhard

AU - Reisinger, David

AU - Heupl, Sarah

AU - Jelinek, Alexander

AU - Schlögl, Sandra

AU - Rossegger, Elisabeth

N1 - Publisher Copyright: © 2024

PY - 2024/6/8

Y1 - 2024/6/8

N2 - Taking inspiration from natural surfaces known for their ability to adaptively remodel their shape, we fabricated stimuli-responsive microstructures by using UV-induced nanoimprint lithography. For this, a fully bio-based dynamic thiol-ene photopolymer was synthetized by the radical mediated addition of a trifunctional eugenol-based thiol (SH3E) crosslinker across an allylated linseed oil (ALELO). To catalyze the bond exchange reactions between the hydroxyl and ester groups within the network, a bio-based eugenol phosphate ester was introduced as a transesterification catalyst. Pure eugenol was further added as a reactive diluent to increase the number of hydroxyl groups and thus, accelerate the thermo-activated bond exchange reactions. Once cured by UV exposure, the dynamic photopolymer is thermally stable up to 250 °C and is able to relax 63% of the original stress within 62 min at 160 °C. Subsequently, films with micropillars, having an aspect ratio of 1:2.5 were prepared by using nanoimprint lithography. The macroscopic reflow capability of the dynamic network enabled a reorientation of the imprinted structures during a thermal reshaping step. The imprints were characterized by 2D/3D optical microscopy, μCT imaging and static water contact angle measurements. Based on the orientation of the micropillars, the water contact angle was varied between 118° and 95°, giving rise to a possible application in microfluidic devices.

AB - Taking inspiration from natural surfaces known for their ability to adaptively remodel their shape, we fabricated stimuli-responsive microstructures by using UV-induced nanoimprint lithography. For this, a fully bio-based dynamic thiol-ene photopolymer was synthetized by the radical mediated addition of a trifunctional eugenol-based thiol (SH3E) crosslinker across an allylated linseed oil (ALELO). To catalyze the bond exchange reactions between the hydroxyl and ester groups within the network, a bio-based eugenol phosphate ester was introduced as a transesterification catalyst. Pure eugenol was further added as a reactive diluent to increase the number of hydroxyl groups and thus, accelerate the thermo-activated bond exchange reactions. Once cured by UV exposure, the dynamic photopolymer is thermally stable up to 250 °C and is able to relax 63% of the original stress within 62 min at 160 °C. Subsequently, films with micropillars, having an aspect ratio of 1:2.5 were prepared by using nanoimprint lithography. The macroscopic reflow capability of the dynamic network enabled a reorientation of the imprinted structures during a thermal reshaping step. The imprints were characterized by 2D/3D optical microscopy, μCT imaging and static water contact angle measurements. Based on the orientation of the micropillars, the water contact angle was varied between 118° and 95°, giving rise to a possible application in microfluidic devices.

KW - Biobased thiol-ene networks

KW - Nanoimprint lithography

KW - Photopolymerization

KW - Switchable surfaces

KW - Vitrimers

UR - http://www.scopus.com/inward/record.url?scp=85195788202&partnerID=8YFLogxK

U2 - 10.1016/j.reactfunctpolym.2024.105972

DO - 10.1016/j.reactfunctpolym.2024.105972

M3 - Article

AN - SCOPUS:85195788202

VL - 202.2024

JO - Reactive & functional polymers

JF - Reactive & functional polymers

SN - 1381-5148

IS - September

M1 - 105972

ER -