2 results about "Citrate ion" patented technology

This invention discloses a natural polysaccharide-based multilayer composite encapsulated probiotic and its preparation method, relating to the field of functional food and microbial preparation technology. This invention provides metabolic substrates for the probiotics through a probiotic-prebiotic co-encapsulation core located in the innermost layer, enabling them to maintain physiological activity during encapsulation. The first anionic polysaccharide encapsulation layer uses sodium alginate, which forms a three-dimensional gel network in a calcium-ion-containing curing solution. In the acidic environment of the stomach, the carboxyl groups in the calcium alginate gel undergo carboxylation, and the network shrinks and densifies, effectively blocking the invasion of hydrogen ions and pepsin, thus physically isolating the probiotics from gastric juice. When the encapsulated probiotics enter the small intestine and colon, the chitosan in the second pH-responsive composite encapsulation layer undergoes a conformational change due to amino deprotonation. Simultaneously, phosphate and citrate ions in the outer environment exchange ions with calcium alginate, achieving a triggered release of the probiotics in the colon.

This application discloses a hydrogel with high mechanical strength and its preparation method. A bidirectional photoinitiation system and two-dimensional conductive nanomaterial MXene are introduced into a pregel solution to initiate a free radical polymerization reaction of AAm monomers, generating PAAm chains. Combined with freeze casting, microphase separation occurs using a directionally grown ice crystal induction system, promoting aggregation and entanglement between PVA chains and between PVA and PAAm chains, forming crystalline regions. MXene nanosheets bind to PAAm and PVA chains via hydrogen bonds, constructing a preliminary hydrogel network. The gel is then immersed in a sodium citrate solution. Driven by a concentration gradient, citrate ions form strong coordination with hydroxyl groups on the PVA chains, inducing hydrogen bond cross-linking and well-defined crystalline domains in the pre-concentrated polymer chains, thus enhancing the gel's strength and modulus. The preparation method is simple and efficient, providing an effective strategy for preparing ultra-tough, high-strength, stretchable, and resilient hydrogels.