A5023751574- Advanced Polymer Synthesis and Characterization
- Surfactants and Colloidal Systems
- Polymer Surface Interaction Studies
- Nanoparticle-Based Drug Delivery
- Lipid Membrane Structure and Behavior
- Advanced biosensing and bioanalysis techniques
- Pickering emulsions and particle stabilization
- Hydrogels: synthesis, properties, applications
- Polymer Nanocomposites and Properties
- Innovative Microfluidic and Catalytic Techniques Innovation
- Photoreceptor and optogenetics research
- RNA Interference and Gene Delivery
- DNA and Nucleic Acid Chemistry
- Fuel Cells and Related Materials
- Block Copolymer Self-Assembly
- biodegradable polymer synthesis and properties
- Supramolecular Self-Assembly in Materials
- Phase Equilibria and Thermodynamics
RWTH Aachen University
2012-2019
Enzymes regulate complex functions and active behavior in natural systems have shown increasing prospect for developing self-regulating soft matter systems. Striving advanced autonomous hydrogel materials with fully programmable, self-regulated life cycles, we combine two enzymes an antagonistic pH-modulating effect a feedback-controlled biocatalytic reaction network (BRN) couple it to pH-responsive DNA hydrogels realize distinct preprogrammable lag times lifetimes closed The BRN enables...
The influence of architecture on polymer interactions is investigated and differences between branched linear copolymers are found. A comprehensive picture drawn with the help a fluorescence approach (using pyrene 4HP as probe molecules) together IR or NMR spectroscopy X-ray/light scattering measurements. Five key aspects addressed: (1) synergistic intramolecular complexation within miktoarm stars. proximity thermoresponsive poly(propylene oxide) (PPO) poly(dimethylaminoethyl methacrylate)...
We report a novel approach to realizing programmable encapsulation and following release of different compounds in sequential way from multicompartmental microcapsules assembled preformed polymersomes. The polymersomes, or polymeric vesicles, are formed through electrostatic interactions between cationic miktoarm star polymer, namely poly(ethylene oxide)113-(quaternized poly(2-(dimethylamino)ethyl methacrylate)60)4, linear anionic polyelectrolyte, (poly(styrenesulfonate)20), then used as the...
A noncentrosymmetric, star-shaped polymeric system is presented, which forms unimolecular micelles upon complexation of poly(propylene oxide) (PPO) with poly(dimethylaminoethyl methacrylate) (PDMAEMA). The influence macromolecular architecture on the hydrophobicity PPO and its interaction PDMAEMA investigated. Within stars, a complex between formed, lowering interfacial tension hydrophobic domain (PDMAEMA acts as "microsurfactant" for PPO). This leads to pronounced drop in aggregation number...
Statistical copolymers of N-isopropyl acrylamide (NIPAM) and N,N-diethyl (DEAAM) show a pronounced synergistic depression in their cloud points, though both homopolymers phase separate at significantly higher temperatures close to 30 °C (e.g., Polymer2009, 50, 519). While separation occurs 20 for the statistical copolymers, influence monomeric sequential arrangement along backbone was not addressed so far. Thus, we report on thermosensitive properties diblock copolymer PDEAAM-b-PNIPAM...
Segregation is a well-known principle for micellization, as solvophobic components try to minimize interactions with other entities (such solvent) by self-assembly. An opposite based on complexation (or coacervation), leading the coassembly/association of different components. Most cases in literature rely only one these modes, though classical micellization scheme spherical micelles, wormlike and vesicles) can be enriched subtle balance segregation complexation. Because their counteraction,...
Abstract Near‐equilibrium stimulus‐responsive polymers have been used extensively to introduce morphological variations in dependence of adaptable conditions. Far‐less‐well studied are triggered transformations at constant These require the involvement metastable states, which either able approach equilibrium state after deviation from metastability or can be frozen on returning nonequilibrium equilibrium. Such functional macromolecular systems hold great promise for on‐demand...
A time-saving phase-diagram screening is introduced for the self-assembly of miktoarm star polymers with different arm numbers insoluble part. Agreeing theory, all conventional micellar morphologies (spherical star-like micelles, cylindrical micelles and vesicles) can be accessed by adjusting average number when blending stars diblock copolymers (at constant arm/block lengths). Additionally, a rare clustered vesicle phase detected. Hence, this approach permits an easy tuning equilibrium...
Binary diblock copolymers and corresponding ternary miktoarm stars are studied at oil-water interfaces. All polymers contain oil-soluble poly(propylene oxide) PPO, water-soluble poly(dimethylaminoethyl methacrylate) PDMAEMA and/or poly(ethylene PEO. The features of their Langmuir compression isotherms well related to the ones homopolymers. Within Langmuir-trough, PEO-b-PPO acts as most effective amphiphile compared other PPO-containing copolymers. In contrast, show a complexation PPO for...
The preparation of miktoarm stars, based on poly(ethylene oxide) (PEO), poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) and either poly(propylene (PPO) or poly(ethyl glycidyl ether) (PEGE), is described. Hereby, partly protected dipentaerythritol (dipentaerythritoldiacetonide) used as a bifunctional alcohol in polymer-based Williamson ether synthesis to become the core star. Mesylated PEO reacted first with excess dipentaerythritoldiketal. This ensures full modification one telechelic...
The intramolecular complex formation occurring in miktoarm star polymers and block copolymers is investigated experimentally by means of Monte Carlo simulations. driving force the an attractive interaction between different blocks. In simulations, a simple bead–spring model with Lennard-Jones potential used to mimic complexation. effect topology (arm number) composition length) simulated. Experimentally, star-shaped polymeric systems diblock poly(propylene oxide) (PPO)...
We propose a strategy to counteract the salt-driven disassembly of multiliposomal complexes made by electrostatic co-assembly anionic small unilamellar liposomes and cationic star-shaped polyelectrolytes (made quaternized poly(dimethylaminoethyl methacrylate) (qPDMAEMA100)3.1). The combined action (qPDMAEMA100)3.1 nonionic polymer (PEO12-b-PPO45)4, which comprises diblock copolymer arms uniting poly(ethylene oxide) PEO inner block poly(propylene PPO terminal block, leads stabilization these...