A new method for exfoliation of hexagonal boron nitride (h-BN) into few-layered nanosheets has been developed by employing noncovalent assembly of networks upon association with a supramolecular polymer. In this work, we developed a simple, reliable, effective approach for preparation of exfoliated h-BN nanosheets from bulk h-BN via liquid-phase exfoliation using a low-molecular weight adenine-functionalized polypropylene glycol (A-PPG) supramolecular polymer. A-PPG self-assembled into either long-range ordered lamellar or micelle-like structures on the surface of h-BN because of the strong specific interactions between A-PPG and h-BN. The level of h-BN nanosheet exfoliation could be controlled by adjusting the amount of A-PPG incorporated. This newly developed composite exhibited excellent phase transition behavior and thermal stability, and few-layer thickness with good dispersion of h-BN nanosheets, indicating self-assembled A-PPG functions as an efficient dispersant and stabilizer to manipulate the physical and morphological properties of exfoliated h-BN. This method of producing multifunctional exfoliated h-BN provides a unique paradigm for developing the next generation of thermoconductive devices and solution-processed semiconductors.

Novel dynamic single-chain polymeric nanoparticles not only significantly improve drug transport efficiency in vitro but can also reside stably and facilitate precisely triggered drug-release in tumor-like microenvironments.

Complementary nucleobase-functionalized polymeric micelles, a combination of adenine-thymine (A-U) base pairs and a blend of hydrophilic-hydrophobic polymer pairs, can be used to construct 3D supramolecular polymer networks; these micelles exhibit excellent self-assembly ability in aqueous solution, rapid pH-responsiveness, high drug loading capacity, and triggerable drug release. In this study, a multi-uracil functionalized poly(ε-caprolactone) (U-PCL) and adenine end-capped difunctional oligomeric poly(ethylene glycol) (BA-PEG) are successfully developed and show high affinity and specific recognition in solution owing to dynamically reversible A-U-induced formation of physical cross-links. The U-PCL/BA-PEG blend system produces supramolecular micelles that can be readily adjusted to provide the desired critical micellization concentration, particle size, and stability. Importantly, in vitro release studies show that doxorubicin (DOX)-loaded micelles exhibit excellent DOX-encapsulated stability under physiological conditions. When the pH value of the solution is reduced from 7.4 to 5.0, DOX-loaded micelles can be rapidly triggered to release encapsulated DOX, suggesting these polymeric micelles represent promising candidate pH-responsive nanocarriers for controlled-release drug delivery and pharmaceutical applications.

Cu nano-particles (Cu-NPs) were embedded into the SiO2 layer of a Cu/SiO2/Pt structure to examine their influence on resistive switching characteristics. The device showed a reversible resistive switching behavior, which was due to the formation and rupture of a Cu-conducting filament with an electrochemical reaction. The Cu-NPs enhanced the local electric field within the SiO2 layer, which caused a decrease in the forming voltage. During successive switching processes, the Cu-NP was partially dissolved, which changed its shape. Therefore, the switching voltages were not reduced. Moreover, the Cu-NPs caused a non-uniform Cu concentration within the SiO2 layer; thus, the Cu-conducting filament should be formed in a high Cu concentration region, which improves switching dispersion. The Cu-NPs within the SiO2 layer stabilize the resistive switching, resulting in a larger switching window and better endurance characteristics.

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