Temperature and pH dual-responsive supramolecular hydrogels based on riboflavin sodium phosphate and 2,6-Diaminopurine with thixotropic and fluorescent properties

High internal phase double emulsions stabilized by modified pea protein-alginate complexes: Application for co-encapsulation of riboflavin and β-carotene

The application of many hydrophilic and hydrophobic nutraceuticals is limited by their poor solubility, chemical stability, and/or bioaccessibility. In this study, a novel Pickering high internal phase double emulsion co-stabilized by modified pea protein isolate (PPI) and sodium alginate (SA) was developed for the co-encapsulation of model hydrophilic (riboflavin) and hydrophobic (β-carotene) nutraceuticals. Initially, the effect of emulsifier type in the external water phase on emulsion formation and stability was examined, including commercial PPI (C-PPI), C-PPI-SA complex, homogenized and ultrasonicated PPI (HU-PPI), and HU-PPI-SA complex. The encapsulation and protective effects of these double emulsions on hydrophilic riboflavin and hydrophobic β-carotene were then evaluated. The results demonstrated that the thermal and storage stabilities of the double emulsion formulated from HU-PPI-SA were high, which was attributed to the formation of a thick biopolymer coating around the oil droplets, as well as thickening of the aqueous phase. Encapsulation significantly improved the photostability of the two nutraceuticals. The double emulsion formulated from HU-PPI-SA significantly improved the in vitro bioaccessibility of β-carotene, which was mainly attributed to inhibition of its chemical degradation under simulated acidic gastric conditions. The novel delivery system may therefore be used for the development of functional foods containing multiple nutraceuticals.

Fabrication of multifunctional bio-macromolecule organic-inorganic hybrid system for protein silk: Photochromic, UV protection, fire-proof and super durability

Nowadays, high value-added and multifunctional textiles have attracted widespread attention due to the changing demands of modern life. This study focused on the fabrication of silk with photochromism, flame retardancy, UV resistance and durability using riboflavin sodium phosphate (RSP) and various metal ions (Fe2+, Fe3+, Al3+, and Ti4+). Attractively, the photochromic performance was one of the most distinctive features of the modified silk, and the yellow silk fabric turned into fluorescent green under UV lamp. After a detailed comparison, it was determined that RSP/Fe3+ hybrid system was most effective in improving anti-UV performance of the silk with a high UPF of 25.8, achieving a "Good" level of UV protection. Specifically, it achieved a B1 fire protection with a low damaged-length of 9.4 cm and a high LOI of 28.3 %. Additionally, the modified silk showed the lowest smoke density, reducing by approximately 84.1 % versus that of pristine silk. Moreover, the modified silk was able to meet the B1 classification and the "Good" UV protection requirements even after 75 washing cycles, making it more durable than most functional textiles reported. The further analysis indicated that RSP and metal ions can synergistically enhance the condensed-phase action, thereby improving the fire resistance of silk.

Simultaneous and Efficient Removal of Oleophilic and Hydrophilic Stains from Polyurethane by the Combination of Easy-Cleaning and Self-Cleaning

The simultaneous and efficient removal of oleophilic and hydrophilic stains from polyurethane (PU) is realized by combining the easy-cleaning from the hydrophilic thermoresponsive hydrogel coating containing acrylamide (AAm), gum arabic (GA), and (ethylene glycol) methyl ether methacrylate (OEGMA₃₀₀) P(GA/AAm/OEGMA₃₀₀) and the self-cleaning from the embedded nonmetallic photocatalyst g-C₃N₄. Due to the existence of strong hydrogen bonds between the hydroxyl groups in the hybrid hydrogel coating and the hydroxyl/carboxyl groups in the plasma-treated PU, the hybrid hydrogel coating is very stable on PU. Simultaneously, the acrylamide network in the hybrid hydrogel coating enhances its mechanical strength. Because the transition temperature of OEGMA₃₀₀ is well above the room temperature, the cross-linked coating remains hydrophilic in ambient conditions. Thus, oleophilic stains, such as oil and grease, can be easily removed from the coating surface. In addition, the embedded photocatalyst g-C₃N₄ in the hybrid hydrogel coating introduces the extra capability of decomposing organic compounds under sunshine, which favors the removal of hydrophilic stains such as dyes and wines. After sunlight illumination and simply rinsing with water, both hydrophilic and oleophilic stains can be easily removed. Moreover, this joint cleaning performance can work for a long time. Even after four consecutive cycles, both the easy-cleaning to oleophilic stains by the hydrophilic hydrogel surface and self-cleaning to the hydrophilic stains by the embedded g-C₃N₄ remain unchanged.