Reactive Additive Capillary Stamping with Double Network Hydrogel-Derived Aerogel Stamps under Solvothermal Conditions

Abstract

Integration of solvothermal reaction products into complex thin-layer architectures is frequently achieved by combinations of layer transfer and subtractive lithography, whereas direct additive substrate patterning with solvothermal reaction products has remained challenging. We report reactive additive capillary stamping under solvothermal conditions as a parallel contact-lithographic access to patterns of solvothermal reaction products in thin-layer configurations. To this end, corresponding precursor inks are infiltrated into mechanically robust mesoporous aerogel stamps derived from double-network hydrogels. The stamp is then brought into contact with a substrate to be patterned under solvothermal reaction conditions inside an autoclave. The precursor ink forms liquid bridges between the topographic surface pattern of the stamp and the substrate. Evaporation-driven enrichment of the precursors in these liquid bridges, along with their liquid-bridge-guided conversion into the solvothermal reaction products, yields large-area submicron patterns of the solvothermal reaction products replicating the stamp topography. For example, we prepared thin hybrid films, which contained ordered monolayers of superparamagnetic submicron nickel ferrite dots prepared by solvothermal capillary stamping surrounded by nickel electrodeposited in a second orthogonal substrate functionalization step. The submicron nickel ferrite dots acted as a magnetic hardener, halving the remanence of the ferromagnetic nickel layer. In this way, thin-layer electromechanical systems, transformers, and positioning systems may be customized.

Solvent-Free High-Temperature Capillary Stamping of Stimuli-Responsive Polymers: Wettability Management by Orthogonal Substrate Functionalization

“…The applied heating and cooling rates amounted to 20 K/min. For high-temperature capillary stamping we adapted a procedure reported elswhere using a homemade stamping device (Figure S3). The flat nickel surface of the infiltrated Ni/MnO 2 composite stamps was glued onto the upper part of a stamping device with heat-resistant double-sided adhesive tape.…”

“…Moreover, the substrate properties may be customized by orthogonal functionalization of the substrate areas between the microdots. 23,24 Here, we show that solvent-free high-temperature capillary stamping is a potential manufacturing platform yielding tailored surfaces with switchable wettability by additive lithographic high-temperature deposition of stimuli-responsive polymers�optionally mixed with solid additives. As example, we performed high-temperature capillary stamping of melts of the stimuli-responsive ferrocene-containing polymer poly(2-(methacryloyloxy)ethyl ferrocenecarboxylate) (PFcMA) 25−27 blended with multiwalled carbon nanotubes (CNTs).…”

“…Patterns of discrete stimuli-responsive polymer microdots may have additional advantages over continuous coatings such as suppression of crack propagation and delamination. Moreover, the substrate properties may be customized by orthogonal functionalization of the substrate areas between the microdots. , …”

“…Stamps exhibiting continuous pore systems − have been used for additive substrate patterning in automatized configurations and even under the extreme conditions of solvothermal syntheses . However, percolative transport of viscous mixtures containing polymers and additional components impeding flow, such as CNTs, through porous stamps might be too slow for efficient stamping procedures.…”

High‐Temperature Melt Stamping of Polymers Using Polymer/Nanoporous Gold Composite Stamps

“…Recently, high‐temperature stamping of polymer melts with composite stamps consisting of a solid metal core coated with a relatively thin porous metal oxide layer was reported. [ 15 ] In this configuration, a limited amount of polymer melt is adsorbed to the porous oxide layer (cf. Figure S1, Supporting Information) for a schematic overview of strategies for the solvent‐free deposition of polymer microstructures on receiving counterpart substrates based on the use of stamps).…”