Preparation And Application Of Functionalized Iron Tetroxide From Proanthocyanidins

Proanthocyanin is a kind of biological flavonoid compound with special molecular structure,which has antioxidant and free radical elimination effects.Proanthocyanin are found in many plants,especially in grape seeds.Structurally,proanthocyanin are composed of various amounts of catechins combined with epicatechins.Catechin,also known as catechin acid and catechin essence,is a kind of phenolic active substance extracted from natural plants such as tea.Magnetic nanocomposites are materials with magnetic properties and many other excellent properties formed by combining magnetic inorganic particles（Fe₃O₄）with other active molecules.In this study,Fe₃O₄ nanoparticles and their composites were prepared by hydrothermal synthesis with Proanthocyanin and catechins.1.Preparation and removal of heavy metal ions from proanthocyanidin-functionalized Fe₃O₄.Firstly,the feasibility of extracting proanthocyanin from grape seeds was verified,but the purity was not high.The main component of grape seed extract is proanthocyanin so pure procyanidins hydrothermal method was used to prepare Fe₃O₄,and the obtained Fe₃O₄ particles showed obvious agglomeration with an average size of 47±7.3 nm.FTIR indicates that the hydroxyl group of proanthocyanidin interacts with the surface of Fe₃O₄ particles,which makes Fe₃O₄ particles have good stability.The results of the study on the removal of heavy metal ions Cu2+,Cd2+and Pb2+ by Fe₃O₄ particles in aqueous solution indicate that the removal efficiency of proanthocyanidin-functionalized Fe₃O₄ particles on heavy metal ions is as high as over 90%,which is expected to be used as a new adsorbent for the removal of water environmental pollution.2.Preparation and removal of heavy metal ions by the catechin functionalized.Fe₃O₄ nanocomposites.The catechin functionalized Fe₃O₄ was prepared in aqueous solution by hydrothermal method.The catechin-functionalized Fe₃O₄ particles were spherical in structure and distributed evenly,with an average size of 46 nm.The results of the study on the removal of heavy metal ions Cu2+,Cd2+ and Pb2+ by catechin-functionalized Fe₃O₄ particles in aqueous solution indicate that catechin-functionalized Fe₃O₄ particles also have a high removal efficiency for heavy metal ions.3.Preparation and antibacterial activity of proanthocyanidin-functionalized Fe₃O₄-Ag nanocomposites.XRD measurements show that the silver nanoparticles in the composite have crystal structure.TEM showed that the particles were basically spherical,with an average size of 18±2.5nm.The antibacterial activity of proanthocyanidin-functionalized Fe₃O₄-Ag nanocomposites against gram-positive bacteria,gram-negative bacteria and fungi was tested.Proanthocyanidin-functionalized Fe₃O₄-Ag nanocomposite still has a high efficiency in removing heavy metal ions Cu2+,Cd2+ and Pb2+ in aqueous solution so this nanocomposite has both antibacterial activity and the ability to remove heavy metal ions.4.Preparation and antibacterial activity of catechin-functionalized Fe₃O₄-Ag nanocomposites.XRD measurements show that the silver nanoparticles in the composite have crystal structure.Transmission electron microscopy observation showed that the morphology of Fe₃O₄-Ag nanoparticles was spherical and the average size was 25 nm.The antibacterial experiments showed that the bactericidal efficiency of proanthocyanidin-silver nanomaterials against Escherichia coli,Staphylococcus aureus and Ideococcus albicans was lower than that of proanthocyanidin-functionalized Fe₃O₄-Ag nanocomposites,because proanthocyanidin itself had certain bacteriostatic ability.Fe₃O₄ nanoparticles.prepared by proanthocyanin and catechins and their composites have excellent magnetic properties of magnetic particles.Experiments on the removal of heavy metal ions show that Fe₃O₄ nanoparticles have good adsorption properties.Bacteriostatic experiments show that the composite material has excellent bacteriostatic effect.Therefore,it has a wide application prospect in the field of separating heavy metal ions and bacteriostasis.