New strategies for the construction of eggshell powder reinforced starch based fire hazard suppression biomaterials with tailorable thermal, mechanical and oxygen barrier properties

Exploiting Waste towards More Sustainable Flame-Retardant Solutions for Polymers: A Review

The development of sustainable flame retardants is gaining momentum due to their enhanced safety attributes and environmental compatibility. One effective strategy is to use waste materials as a primary source of chemical components, which can help mitigate environmental issues associated with traditional flame retardants. This paper reviews recent research in flame retardancy for waste flame retardants, categorizing them based on waste types like industrial, food, and plant waste. The paper focuses on recent advancements in this area, focusing on their impact on the thermal stability, flame retardancy, smoke suppression, and mechanical properties of polymeric materials. The study also provides a summary of functionalization methodologies used and key factors involved in modifying polymer systems. Finally, their major challenges and prospects for the future are identified.

Preparation of high strength, self-healing conductive hydrogel based on polysaccharide and its application in sensor

The development of cost-effective, eco-friendly conductive hydrogels with excellent mechanical properties, self-healing capabilities, and non-toxicity holds immense significance in the realm of biosensors. The biosensors demonstrate promising applications in the fields of biomedical engineering and human motion detection. A unique double-network hydrogel was prepared through physical-chemical crosslinking using chitosan (CS), polyacrylic acid (AA), and sodium alginate (SA) as raw materials. The prepared double-network hydrogels exhibited exceptional mechanical properties, as well as self-healing and conductive capabilities. Polyacrylic acid as the first layer network, while chitosan and sodium alginate were incorporated to establish the second layer network through electrostatic interactions, thereby imparting self-healing and self-recovery properties. The hydrogel was subsequently immersed in the salt solution to induce network winding. The mechanical robustness of the hydrogel was significantly enhanced through synergistic coordination of covalent and non-covalent interactions. When the concentration of sodium alginate was 20 g/L, the double-network hydrogel exhibits enhanced mechanical properties, with a tensile fracture stress of up to 1.31 MPa and a strength of 4.17 MPa under 80% compressive deformation. Furthermore, the recovery rate of this double-network hydrogel reached an impressive 89.63% within a span of 30 min. After 24 h without any external forces, the self-healing rate reached 26.11%, demonstrating remarkable capabilities in terms of self-recovery and self-healing. Furthermore, this hydrogel exhibited consistent conductivity properties and was capable of detecting human finger movements. Hence, this study presents a novel approach for designing and synthesizing environmentally friendly conductive hydrogels for biosensors.

Advances in biomaterial production from animal derived waste

Animal derived waste, if not disposed properly, could pose a threat to the environment and its inhabitants. Recent advancements in biotechnological and biomedical interventions have enabled us to bioengineer these valuable waste substrates into biomaterials with diversified applications. Rearing and processing of poultry, cattle, sheep, goat, pig, and slaughterhouse waste can aid in effective waste valorization for the fabrication of biopolymers, composites, heart valves, collagen, scaffolds, pigments and lipids, among other industrially important biomaterials. Feathers and eggshell waste from the poultry industry can be used for producing keratinous proteins and biocomposites, respectively. Cattle dung, hoofs and cattle hide can be used for producing hydroxyapatite for developing scaffolds and drug delivery systems. Porcine derived collagen can be used for developing skin grafts, while porcine urinary bladder has antiangiogenic, neurotrophic, tumor-suppressive and wound healing properties. Sheep teeth can be used for the production of low-cost hydroxyapatite while goat tissue is still underutilized and requires more in-depth investigation. However, hydrolyzed tannery fleshings show promising potential for antioxidant rich animal feed production. In this review, the recent developments in the production and application of biomaterials from animal waste have been critically analyzed. Standardized protocols for biomaterial synthesis on a pilot scale, and government policy framework for establishing an animal waste supply chain for end users seem to be lacking and require urgent attention. Moreover, circular bioeconomy concepts for animal derived biomaterial production need to be developed for creating a sustainable system.