Project Details
Projekt
Adaptive Polymergele mit kontrollierter Netzwerkstruktur
Applicant
Professor Sebastian Seiffert, Ph.D.
Subject Area
Preparatory and Physical Chemistry of Polymers
Term
from 2019 to 2022
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 397384169
Amphiphilic conetworks (ACN) consist of hydrophobic and hydrophilic polymer building blocks that form a common percolated network structure able to swell in both water and organic media. This amphiphilic swellability leads to solvent-sensitive viscoelasticity and permeability for hydrophilic, hydrophobic, and amphiphilic substances. Both can serve as a basis for versatile applications such as soft contact lenses, switchable cell substrates, or antimicrobial coatings. The solvent-sensitive viscoelastic and perm-selective properties, however, are determined by the polymer network nano- and microstructure, which, in turn, is further complexed by the presence of clusters and partially collapsed domains in selective media. Our research initiative aims at delivering quantitative relations between these structures and properties. To reach that goal, we start from model-network structures as obtained by Sakai's and Shibayama's tetra-PEG approach, which we will adopt for ACN. To make this truly meaningful, we will realize two different classes of ACN. One class consists of covalently and permanently connected building blocks; another class consist of ionically and transient-reversibly connected building blocks. Whereas the nano-and microstructures of the first are determined by both the conditions during a current state of swelling in an experiment as well as the conditions during the moment of network formation, the latter are determined only by the conditions at measurement. Comparison of both these complementary classes of ACN allows the impact of network irregularity as formed during the network percolation to be clearly recognized. On this basis, we will determine the impact of the chemical and topological constitution of the network building blocks, their stoichiometric ratio, and further reactions parameters such as concentration, temperature, reactivity, and viscosity on the resulting network structure of covalently interlinked ACN, and how this structure is further complexed by selective swelling and collapse of their oppositely philic parts. In particular, we will determine in what parameter space large, potentially percolated domains will be present and how the aggregation number of the collapsed building blocks in selective media is. On the basis of these structural models, we will focus on the interplay of the network structures and their viscoelastic mechanics and perm-selective permeability both at the gel-specimen surface and in their bulk. All these studies will be conducted both from experimental and theoretical perspectives. It is our overall goal to undergo intense feedback between experiment and theory, with the aim to derive quantitative structure-property relations for ACN as a basis for rational design of soft materials based on them.
DFG Programme
Research Units
