Vitrimers: Current research trends and their emerging applications

Dynamic and reconfigurable materials from reversible network interactions

Recent Advances in Hydrogels

Stimuli-responsive temporary adhesives constitute a rapidly developing class of materials defined by the modulation of adhesion upon exposure to an external stimulus or stimuli. Engineering these materials to shift between two characteristic properties, strong adhesion and facile debonding, can be achieved through design strategies that target molecular functionalities. This perspective reviews the recent design and development of these materials, with a focus on the different stimuli that may initiate debonding. These stimuli include UV light, thermal energy, chemical triggers, and other potential triggers, such as mechanical force, sublimation, electromagnetism. The conclusion discusses the fundamental value of systematic investigations of the structure–property relationships within these materials and opportunities for unlocking novel functionalities in future versions of adhesives.

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Stimuli-responsive temporary adhesives: enabling debonding on demand through strategic molecular design

This study reports healable, recyclable, and adhesive rubber composites equipped with ester linkages, Zn2+ ionic bonds, and H-bonds based on carboxylic styrene butadiene rubber (XSBR), nano-ZnO, and diglycidyl ether of bisphenol A (DGEBA). Zn2+ ionic cross-links are introduced into XSBR networks through the acid-base reaction between nano-ZnO and carboxyl groups of XSBR. The in-situ generated Zn2+ is thus evenly dispersed in the rubber matrix to serve as transesterification catalyst, which promotes the healing and reprocessing of the rubber composites at a higher temperature. The healing efficiency of the rubber composites can realize 75% and further improved to 90% after introducing additional hydroxyl groups. The rubber composites can reprocess at least 5 times. Moreover, the rubber composites are easily disintegrated to recycle neat XSBR due to the dissociation of ester linkages in the alkaline solution. Interestingly, the rubber composites show a surprising reversible adhesion property under water stimulation. 

Healable, Recyclable, and Adhesive Rubber Composites Equipped with Ester Linkages, Zinc Ionic Bonds, and Hydrogen Bonds

We demonstrated the modular synthesis of polymer thermosets exhibiting programmed responses that arise from two predesigned functional units: a reversible cross-linker and a self-immolative linker....

Dual Cross-Linked, Polymer Thermosets: Modular Design,Reversible Transformation, and Triggered Debonding

Biobased Stimuli-Responsive Hydrogels That Comprise Supramolecular Interpenetrating Networks and Exhibit Programmed Behaviors

Fibrous mesoporous polymer monoliths: macromolecular design and enhanced photocatalytic degradation of aromatic dyes

This paper demonstrates the hierarchical design of functional, fibrous polymer monoliths. The monoliths are composed of conjugated microporous polymers that not only are embedded with heteroatoms but also feature fibrous yet compressible structures due to the in situ self-assembly process that occurs during the polymerization process. Therefore, the doped nitrogen atoms can allow the growth of zeolitic imidazolate framework (ZIF) nanocrystals, which causes the homogeneous encapsulation of individual fibers. The resulting hybrid monoliths exhibit enhanced physical properties as well as catalytic activity, allowing the formation of an additional coating layer via a thiol-epoxy reaction. The deliberate inclusion of template molecules during the reaction forms molecularly imprinted sites on the fibers to afford functional monoliths. As a proof of concept, the hierarchically designed materials are able to show effective recognition properties toward diethylstilbestrol, an endocrine disruptor, taking advantage of the binding sites that selectively capture the analyte molecules and the fibrous morphology that increases the accessibility of these binding sites. We envisage that the incorporation of various heteroatoms or nanocrystals will bring about the bespoke design of advanced monoliths with autonomous functions, leading to smart textile systems.

Hierarchical Design of Functional, Fibrous, and Microporous Polymer Monoliths for the Molecular Recognition of Diethylstilbestrol.

For biomedical imaging, the interest in noninvasive imaging methods is ever increasing. Among many modalities, photoacoustic imaging (PAI), which is a combination of optical and ultrasound imaging techniques, has received attention because of its unique advantages such as high spatial resolution, deep penetration, and safety. Incorporation of exogenous imaging agents further amplifies the effective value of PAI, since they can deliver other specified functions in addition to imaging. For these agents, carbon-based materials can show a large specific surface area and interesting optoelectronic properties, which increase their effectiveness and have proved their potential in providing a theragnostic platform (diagnosis + therapy) that is essential for clinical use. In this review, we introduce the current state of the PAI modality, address recent progress on PAI imaging that takes advantage of carbon-based agents, and offer a future perspective on advanced PAI systems using carbon-based agents.

Songah Jeong

Papers

Dual Cross-Linked, Polymer Thermosets: Modular Design,Reversible Transformation, and Triggered Debonding

Biobased Stimuli-Responsive Hydrogels That Comprise Supramolecular Interpenetrating Networks and Exhibit Programmed Behaviors

Fibrous mesoporous polymer monoliths: macromolecular design and enhanced photocatalytic degradation of aromatic dyes

Hierarchical Design of Functional, Fibrous, and Microporous Polymer Monoliths for the Molecular Recognition of Diethylstilbestrol.

Recent Progress on Molecular Photoacoustic Imaging with Carbon-Based Nanocomposites.