Search

Polymers conjugated with active agents have applications in biomedicine, anticorrosion, and smart agriculture. When the active agent is used as a drug, corrosion inhibitor, or pesticide, it can be released upon a specific stimulus. The efficiency and the sustainability of active agents are determined by the released kinetics. In this work, we study the fast-release kinetics of 8-hydroxyquinoline (8HQ) from a pH-responsive, random copolymer of methyl methacrylate and 8-quinolinyl-sulfide-ethyl acrylate [P(MMA-co-HQSEA)] by hydrolysis of the β-thiopropionate groups. We used contact angle measurements of sliding drops as an elegant way to characterize the release kinetics. Based on the results gained from 1H nuclear magnetic resonance measurement, fluorescent intensity measurement, and velocity-dependent contact angle measurement, we found that both the hydrolysis rate and polymer conformation affect the release kinetics of 8HQ from a P(MMA-co-HQSEA) film. Polymer chains collapse and further suppress the release from the inner layer in acidic conditions, while polymer chains in a stretched condition further facilitate the release from the inner layer. As a result, the cumulative release rate of 8HQ is higher in the basic condition than in the acidic condition. [ABSTRACT FROM AUTHOR]

Coating metal structures with a protective material is a popular strategy to prevent their deterioration due to corrosion. However, maintaining the barrier properties of coatings after their mechanical damage is challenging. Herein, we prepared multifunctional coatings with self-healing ability to conserve their anticorrosion performance after damage. The coating was formed by blending synthesized redox-responsive copolymers with the ability to release a corrosion inhibitor upon the onset of corrosion with synthesized self-healing polyurethanes containing disulfide bonds. The corrosion rate of steel substrates coated with a blend is approximately 24 times lower than that of steel coated with only self-healing polyurethane. An exceptional healing efficiency, as high as 95%, is obtained after mechanical damage. The antibiofouling property against bacterial and microalgal attachments on coatings is facilitated by the repellent characteristic of fluorinated segments and the biocidal activity of the inhibitor moieties in the copolymer. [ABSTRACT FROM AUTHOR]

Understanding the transport of nanoparticles from and within hydrogels is a key issue for the design of nanocomposite hydrogels for drug delivery systems and tissue engineering. To investigate the translocation of nanocarriers from and within hydrogel networks triggered by changes of temperature, ultrasmall (8 nm) and small (80 nm) silica nanocapsules are embedded in temperature‐responsive hydrogels and non‐responsive hydrogels. The ultrasmall silica nanocapsules are released from temperature‐responsive hydrogels to water or transported to other hydrogels upon direct activation by heating or indirect activation by Joule heating; while, they are not released from non‐responsive hydrogel. Programmable transport of nanocarriers from and in hydrogels provides insights for the development of complex biomedical devices and soft robotics. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Polyhydroxyurethanes (PHUs) have received considerable attention in the last decade as potential alternatives to traditional phosgene‐based polyurethanes (PUs). The development of suitable 5CC (five membered‐ring cyclic carbonate) precursors bearing multiple carbonate moieties (multi‐5CCs) is a key requisite for preparing PHUs by polyaddition reaction with bis‐ or polyamines. Producing sustainable PHUs from CO2‐based five‐membered cyclic carbonates (5CCs) obtained from biobased epoxides is a valuable strategy to bridge CO2 utilization and the upcycling of renewable substrates. In this context, while many multi‐5CC monomers reported in the literature are oil‐based, recent efforts have led to the development of a large variety of multifunctional 5CCs that are produced by the combination of CO2 and renewable resources such as fatty acids and vegetable oils, lignin, terpenes, and sugars. In this work, recent crucial advances (2019—2023) on PHUs prepared from bis‐ and multi‐5CCs produced from CO2 and (partially/potentially) biobased substrates are reviewed with respect to their synthesis, thermal and mechanical properties, and their recent, emerging applications. [ABSTRACT FROM AUTHOR]

Hydrogels can be used in surgeries, which require a support material to maintain the correct anatomy. One major limitation is however the time required for the preparation of hydrogels under urgent conditions. Herein, we report a new method for a very fast preparation of hydrogels at room temperature. Nanofibers of dextran containing vinyl groups produced by electrospinning are loaded with redox- or photo-initiators for radical polymerization. Once dissolved in water, the nanofibers yield hydrogels either spontaneously or upon irradiation with UV light. We also show that the nanofibers can be loaded with active fillers so that hydrogels embedding nanocapsules are obtained. This concept could be applied for the rapid preparation of functional hydrogels which are needed as implants. [ABSTRACT FROM AUTHOR]