Jonas, Ulrich
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Publication Access status: Metadata only , Morphological design of PDVB‐based pArticlesPolymeric microspheres with complex architectures find application as stationary phases for size exclusion separation, solid supports for surface reactions, catalysis, and delivery systems. The micropArticles are commonly made from divinylbenzene by precipitation polymerization or template swelling. Upon combining both methods and applying photopolymerization, we discovered new morphological features that are not solely explicable by the individual processes. Firstly, three types of templates were synthesized by precipitation polymerization: noncrosslinked, slightly crosslinked, and slightly crosslinked with noncrosslinked polystyrene fractions. All template types were swollen with divinylbenzene, which was polymerized by photoinitiation, followed by template extraction. Changes in pArticle size were tracked by light microscopy, while SEM revealed submicron features like hollow cores, toluene‐insoluble walls, and surface grooves from the collapse upon drying of the toluene‐swollen corona. Our investigations indicated that the corona results from chain transfer and crosslinking of the template during photoinitiation. Higher precrosslinking of the template reduced the core cavity volume of the extracted pArticle, while more mobile polystyrene chains led to larger cavities. These architectures are promising model systems for fundamental studies of pArticle interactions, aggregation, and structure formation in the field of colloidal physics.Source Type:Article1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Thermoresponsive and Photocrosslinkable Poly(2‐alkyl‐2‐oxazoline) Toolbox – Customizable Ultralow‐Fouling Hydrogel Coatings for Blood Plasma EnvironmentsThis study focuses on developing surface coatings with excellent antifouling properties, crucial for applications in the medical, biological, and technical fields, for materials and devices in direct contact with living tissues and bodily fluids such as blood. This approach combines thermoresponsive poly(2‐alkyl‐2‐oxazoline)s, known for their inherent protein‐repellent characteristics, with established antifouling motifs based on betaines. The polymer framework is constructed from various monomer types, including a novel benzophenone‐modified 2‐oxazoline for photocrosslinking and an azide‐functionalized 2‐oxazoline, allowing subsequent modification with alkyne‐substituted antifouling motifs through copper(I)‐catalyzed azide‐alkyne cycloaddition. From these polymers surface‐attached networks are created on benzophenone‐modified gold substrates via photocrosslinking, resulting in hydrogel coatings with several micrometers thickness when swollen with aqueous media. Given that poly(2‐alkyl‐2‐oxazoline)s can exhibit a lower critical solution temperature in water, their temperature‐dependent solubility is compared to the swelling behavior of the surface‐attached hydrogels upon thermal stimulation. The antifouling performance of these hydrogel coatings in contact with human blood plasma is further evaluated by surface plasmon resonance and optical waveguide spectroscopy. All surfaces demonstrate extremely low retention of blood plasma components, even with undiluted plasma. Notably, hydrogel layers with sulfobetaine moieties allow efficient penetration by plasma components, which can then be easily removed by rinsing with buffer.Source Type:Article2
