Supramolecular Chemistry of Carbon-Based Dots Offers Widespread Opportunities

Carbon dots are an emerging class of nanomaterials that has recently attracted considerable attention for applications that span from biomedicine to energy. These photoluminescent carbon nanoparticles are defined by characteristic sizes of <10 nm, a carbon-based core and various functional groups at their surface. Although the surface groups are widely used to establish non-covalent bonds (through electrostatic interactions, coordinative bonds, and hydrogen bonds) with various other (bio)molecules and polymers, the carbonaceous core could also establish non-covalent bonds (ππ stacking or hydrophobic interactions) with π-extended or apolar compounds. The surface functional groups, in addition, can be modified by various post-synthetic chemical procedures to fine-tune the supramolecular interactions. Our contribution categorizes and analyzes the interactions that are commonly used to engineer carbon dots-based materials and discusses how they have allowed preparation of functional assemblies and architectures used for sensing, (bio)imaging, therapeutic applications, catalysis, and devices. Using non-covalent interactions as a bottom-up approach to prepare carbon dots-based assemblies and composites can exploit the unique features of supramolecular chemistry, which include adaptability, tunability, and stimuli-responsiveness due to the dynamic nature of the non-covalent interactions. It is expected that focusing on the various supramolecular possibilities will influence the future development of this class of nanomaterials.

Self-healing hydrogel sensors with multiple shape memory properties for human motion monitoring

Shape memory hydrogels offer new opportunities for the development of smart wearables due to their intelligent responsiveness.

New star-shape memory polyurethanes capable of thermally induced recovery and hydrogen bond-self-healing

Star-shape memory polyurethanes that combine thermally responsive and self-healing properties.

Superhydrophobic Shape Memory Polymer Microarrays with Switchable Directional/Antidirectional Droplet Sliding and Optical Performance

Bioinspired smart surfaces with switchable wettability and optical performance have aroused much attention in the past few years. However, almost all reported surfaces focused on regulating single surface function. In this work, inspired by the butterfly wings, a novel superhydrophobic surface with shape memory polymer microarrays (SMPAs) was prepared through the integration of three-dimensional printing, replica-molding, and a simple surface treatment. In this superhydrophobic SMPA system, the permanent upright microarrays and temporary tilted microarrays can be reversibly switched owing to the excellent shape memory effect (SME). Accompanied by the structure variations, switchable directional/antidirectional droplet sliding and vivid color conversion as the butterfly wings can be achieved. Moreover, because of the SME, local structure regulation can also be achieved on the surface, and with the help of such an ability, the SMPA was further applied as a multifunctional platform to demonstrate controllable droplet transportation and information storage. This work reports the reversible control of directional/antidirectional droplet sliding and tunable color on a superhydrophobic SMPA, and it is believed that such a smart surface can be potentially applied in many fields, such as microfluidic devices and smart optical chips.