Quick self-grown ternary supramolecules embedded in sodium alginate to fabricate ultralight sponge exhibiting superior flame retardancy.

To mitigate environmental and health risks associated with the use of halogenated flame retardants, effective halogen-free solutions have been extensively explored. In this study, melamine/boric acid/phosphoric acid (MBP)­sodium alginate (SA) sponge was synthesized by treating MBP ternary supramolecules with microwave irradiation via one-pot, facile, and speedy synthesis, obtaining an MBP-SA sponge, a polysaccharide biopolymer. Crosslinking of SA with Ca2+ ion formed an intact network, and this was confirmed using scanning electron microscopy (SEM). Thereafter, the flame retardancy of the as-synthesized SA/MBP sponge was investigated by exposing it to a spirit lamp and a Bunsen burner; the sponge remained intact for up to 540 s and 370 s, respectively, demonstrating the enhanced flame retardancy of MBP supramolecules in the SA/MBP sponge. The limiting oxygen index of the SA/MBP sponge was up to 62 %, demonstrating the self-extinguishing and thermal insulation properties of the as-synthesized sponge. The findings of this study provide insights for developing a new strategy to use SA/MBP sponges for fire protection.

Empowering the flame retardancy and adhesion for various substrates using renewable feedstock.

Developing biobased flame retardant adhesives using a green and simple strategy has recently gained significant attention. Therefore, in this study, we have orange peel waste (OPW) and Acacia gum (AG) phosphorylated at 140 °C to synthesize biomass-derived flame retardant adhesive. OPW is a biomass material readily available in large quantities, which. Has been utilized to produce an eco-friendly, efficient adhesive. Functionalized polysaccharides were used as a binder rather than volatile, poisonous, and unsustainable petroleum-based aldehydes. The P@OPW/AG green adhesive exhibited a higher tensile strength of 11.25 MPa when applied to cotton cloth and demonstrated versatility across various substrates such as glass, cardboard, plastic, wood, and textiles. Additionally, this bio-based robust adhesive displayed remarkable flame-retardant properties. To optimize its flame retardancy, three tests were employed: the spirit lamp flame test, the vertical flammability test (VFT), and the limiting oxygen index (LOI) test. The P@OPW/AG-coated cotton fabric achieved an impressive LOI result of 42 %, while the VFT yielded a char length of only 4 cm. Additionally, during the flame test, P@OPW/AG coated cloth endured more than 845 s of continuous flame illumination. This work offers a sustainable and fire-safe method for creating environmentally friendly high-performance composites using a recyclable bio-based flame-retardant OPW/AG glue.

Waste derived approach towards wealthy fluorescent N-doped graphene quantum dots for cell imaging and H2O2 sensing applications.

Herein, we report the synthesis of a highly fluorescent nitrogen doped graphene quantum dots (N-GQDs) from waste precursors such as melamine sponge and arjuna bark via a microwave treatment and its functional and morphological characterization using various spectroscopy techniques such as optical, FTIR, XPS and TEM. The as-prepared aqueous N-GQD (dia. 2-3 nm) was used for the bio-imaging application using breast carcinoma cell line (MDA-MB-231) as a model, and the locations of all cells in the cytoplasm as well as nuclei were observed to stain brightly in blue fluorescent color successfully. In addition to that, the aqueous N-GQD showed fluorescence quenching behavior in the presence of hydrogen peroxide, which was exploited to sense H2O2, a probable toxin generated in the diseased cells. Importantly, the cell cytotoxicity was measured and found to be non-toxic (70% survival) to the MDA-MB-231 cells even at very high concentration (∼1.8 mg/ml) of the synthesized N-GQD. This study revealing excellent biocompatibility and imaging of the model cancer cells, and sensing of H2O2 by fluorescent quenching, indicates potential in-vivo cell culture applications of the prepared fluorescent N-GQD.