ISBN 978-3-8439-5259-0

978-3-8439-5259-0, Reihe Mikrosystemtechnik

Zhuoling Deng
Self-regenerating Functional Surfaces using Multistacks of Discrete Layer based on Degradable and Depolymerizable Polymers

199 Seiten, Dissertation Albert-Ludwigs-Universität Freiburg im Breisgau (2023), Softcover, B5

Zusammenfassung / Abstract

Sacrificial materials are used in the context of the nuclear industry, electrochemistry, and in the fabrication of microelectromechanical systems. In these areas, the sacrificial material is used for protection of the material of interest from undesired reactions or by taking up space in a process to be removed, i.e., to be "sacrificed" later.

The aim of this work was to create a self-regenerating multistack of discrete polymeric layers in an alternating manner. One layer should provide an antimicrobial function, whereas the other should serve as a sacrificial layer with or without antimicrobial functions.

To achieve this goal, two approaches towards these systems were used based on different degradation mechanisms of sacrificial layer.

In the first approach, the sacrificial layer was made from hydrolysis-based degradable copolymer containing units of sebacic acid and salicylic acid. This copolymer poly[1,10-bis(o-carboxyphenoxy)decanoate] (SA-co-SE) was obtained by polycondensation of diacetoxy terminated 1,10-bis(o-carboxyphenoxy)decanoate.

In the second approach, the sacrificial layer was made from 1,6-elimination-based depolymerizable poly(benzyl carbamate) with triggerable functionalities. It was end-capped with 2-(trimethylsilyl)ethanol or 4-hydroxy-2-butanone, i.e., PC-TMSE and PC-4H2B, respectively.

When PC-4H2B using as a sacrificial layer, mechanical forces originating from diffusive mass transport and buoyancy forces in an aqueous medium worked synergistically. They were sufficient to uplift the used functional layer. By shedding the defective or contaminated surface, a new functional surface emerges, which can prolong the service life of a device.