The Study Of Solubilization Capacity On Dendrimier

Dendrimer's specialties are to design the molecular size, shape andfunctional group at the molecular level. Studying systematacially the molecularstructure and performance, developing the function macromolecule with new-type terrninal group are an important research direction. The surface terminalgroup can carry on function transform. There are amido, hydroxyl, carboxyl,ester base, acylamino group, metal chelate compound etc that have already beenreported at present. Because there are active sites and the spacious cavity amongthe center and inside of dendrimers with the dense functional group in surfacee,those make this kind of macromolecule have well enough application prospectsin drug deliver, catalyst carrier, gene therapy, dye industry and membranematerial etc.The dendrimers were synthesized, the poly(amidoamine)(PAMAM)dendrimers were prepared by divergent method with ethylenediamine as core.PAMAM was functioned with tris(tri-hydroxymethyl) amino methane and paraaminobenzoic acid. A type of water-solubility dendrimer with hydroxy andcarboxyl of terminal group was synthesized. The molecular structures of theproduct have been characterized by means of infrared spectrum (IR). Thevalidity of the molecular structure of dendrimer was proved tomatch with thedesigning target molecularThis thesis has explored tentatively the performance of dendrimers, and thestructure characteristics. The surface tensions of half generationpoly(amidoamine) (PAMAM) and dendrimers with hydroxy and carboxyl ofterminal group by drop-volume method. It was found that dendrimers differedfrom traditional surfactants, and intermolecular aggregation did not occur. Theterminal group influenced on the surface activity of dendrimers and the surfacetensions approached those of water with the hydrophilicity of the terminal groupmore increasing. The study of dendrimer solubilization capacity on hard-dissolved guest molecule was discussed emphatically. Benzoic acid, buprofen,methyl red and disperse red 167 were choiced as hydrophobic drug model. Theability of dendrimers to increase the solubility of hydrophic drug molecules was investingated by UV-VIS spectroscopy. The dendrimers with different endgroups all enhanced the solubility of model drug significantly. Due to CMC wasobserved, the dendrimers in water could be regarded as "unimolecular micelle".The unimolecular micelle has the similar properties to a traditional micelle, butthe micellar structure stabilized in variety of solvents. The inherent stability ofdendritic unimolecular micelles, as well as the ability to encapsulate guestmolecules, makes them good candidates for the hard-dissolved guest moleculesin the fields of medicine and dye industry.