Pentaerythrityl tetra-β-cyclodextrin: Synthesis, characterization and application in multiple responses hydrogel

Highly Flexible and Self-Healing Supercapacitor Enabled by Physically Crosslinking Polymer Hydrogel Electrolyte

Preparation of flexible supercapacitors with excellent mechanical properties and self-healing properties is of great significance but still remains a challenge. A self-healable conductive hydrogel based on poly N-hydroxyethyl acrylamide (PHEAA) is fabricated as electrolyte for supercapacitors. The design of the physically cross-linked dual network, and rich hydrogen bonds endow the hydrogel with robust mechanical properties and strong self-healing ability. The hydrogel exhibited an excellent stretchability (723 %) and a high ionic conductivity (21.8 mS/cm). Specially, by in situ growth of electrode film, a non-laminated supercapacitor is obtained with flexibility and self-healing ability. Due to the non-laminated structure, the supercapacitor can work stably under bending and punching. The supercapacitor possessed an areal capacitance of 253.1 mF/cm2 and the capacitance retention was 80 % after five cutting-healing cycles. The pseudo-capacitance contribution of the supercapacitor after self-healing was discussed. It is noteworthy that the supercapacitor maintains the ability to power a clock after self-healing.

Mono-Dendronized β-Cyclodextrin Derivatives as Multitasking Containers for Curcumin. Impacting Its Solubility, Loading, and Tautomeric Form

In this study, three mono-dendronized β-cyclodextrin (βCD) derivatives (βCD-1G, βCD-2G, and βCD-3G) were used as multitasking containers of curcumin (CUR) to influence its aqueous solubility and tautomerism, both of which are related to its biological activity. We evaluated the relevant physicochemical properties of these containers associated with their potential hosting capacity. All mono-dendronized derivatives exhibited enhanced solubility in different solvents, including water, in comparison with native βCD. Gas-phase geometry optimizations by density functional theory (DFT) confirmed that none of the dendrons blocked the passage of CUR into the βCD cavity, and depending on the generation, different preorganization scenarios were promoted before complexation. Phase solubility diagrams showed that all the dendronized containers have superior performance for solubilizing CUR compared to native βCD. We proved that coprecipitation is most efficient than lyophilization for forming inclusion complexes (ICs) with dendronized containers. Even though βCD-3G with the largest 3G dendron exhibited the highest CUR loading, the complexation of CUR with βCD-2G provided the supramolecular system that contains CUR preferentially in its diketo tautomer, which is known for its antioxidant activity.

Temperature/Reduction Dual Response Nanogel Is Formed by In Situ Stereocomplexation of Poly (Lactic Acid)

A novel type of dual responsive nanogels was synthesized by physical crosslinking of polylactic acid stereocomplexation: temperature and reduction dual stimulation responsive gels were formed in situ by mixing equal amounts of PLA (Poly (Lactic Acid)) enantiomeric graft copolymer micellar solution; the properties of double stimulation response make it more targeted in the field of drug release. The structural composition of the gels was studied by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FT-IR). Using transmission electron microscope (TEM) and dynamic light scattering (DLS) instruments, the differences in morphology and particle size were analyzed (indicating that nanogels have dual stimulus responses of temperature sensitivity and reduction). The Wide-Angle X-ray diffractionr (WAXD) was used to prove the stereocomplexation of PLA in the gels, the mechanical properties and gelation process of the gels were studied by rheology test. The physically cross-linked gel network generated by the self-recombination of micelles and then stereo-complexation has a more stable structure. The results show that the micelle properties, swelling properties and rheological properties of nanogels can be changed by adjusting the degree of polymerization of polylactic acid. In addition, it provides a safe and practical new method for preparing stable temperature/reduction response physical cross-linked gel.

Self-assembly of supra-amphiphiles building block fabricated by β-cyclodextrin and adamantane-based ionic liquid

A new adamantane-based ionic liquid, (11-(((-adamantane-1-carbonyl)oxy)undecyl)-1-methylimidazol-3-ium bromide (AD-C₁₁im), was synthesized from 1-adamantanecarboxylic acid and observed that it can aggregate into micelles in aqueous solution. A number of experiments were conducted to understand the self-assembly of supra-amphiphiles building block fabricated by β-cyclodextrin (β-CD) and adamantane-based ionic liquid at diverse molar ratios. Studies revealed that host–guest interaction between the adamantane group and β-CD occurred and AD-C₁₁im@1β-CD building block formed when same amount β-CD was added. Then the micelles aggregates formed by AD-C₁₁im only turned into spherical vesicles, which was confirmed by AFM, DLS and TEM. Besides, according to the results of AFM, it can be confirmed that the vesicles were monolayer structure. When double amount β-CD was added, both the adamantane group and the hydrophobic chain were encapsulated by β-CD and AD-C₁₁im@2β-CD building block formed. Thus the aggregations changed from vesicles to net-like nanofiber, which was observed by TEM. When the β-CD concentration increased to 40 mM, the formation of light blue hydrogel was observed during the self-assembling process of AD-C₁₁im@2β-CD building block.

The self-assembly of supra-amphiphiles building block fabricated by β-CD and AD-C₁₁im at diverse molar ratios was studied. The micelles of AD-C₁₁im turned into monolayer vesicles, net-like nanofibers and hydrogel at different β-CD/AD-C₁₁im system.