Dendrimers consist of three distinct regions, the core, the dendritic molecule, and the terminal functional group. The gaps between the branches of dendritic molecules form dendritic gaps. The essence of dendrimers are governed by the functional groups, but dendritic gap and internal nucleus in the center of the function are also very important.
Figure 1. Structure of dendeimers.
- Catalyst: Dendrimers have cavities of different sizes inside, and there are a large number of active functional groups inside and outside the molecules. Therefore, active centers of catalysts can be introduced into dendrimers to complete the catalytic process inside the cavities.
- Biomedical field: Dendrimers can be changed through algebra and the number of reactive groups, making it have a higher dispersion and efficiency. The inner cavity and binding point can wrap drug molecules, such as genes, antibodies and vaccines, as a carrier for the targeted transport of drugs. At the same time, by modifying groups on the outer surface of the molecule, the water-solubility and targeting of the drug can be improved, and the controllable release of the drug molecule can be realized.
- Surfactant: As a new surfactant, dendrimers have the advantages of clear structure, amorphous state, low viscosity, high dissolution energy consumption, large number of terminals and high reactivity, and it has a wide application prospect.
- Electroluminescent materials: The luminescence properties of dendritic luminescent materials can be conveniently realized by the exchange of different fluorescent dyes in the central nucleus. In addition, a large number of surface functional groups and different algebras can be selected to obtain some interesting properties, such as carrier transport function, regional isolation effect, solubility, and antenna effect. This type of luminescent material has been considered as the third type of electroluminescent material. Dendrimers are composed of central nuclei and a large number of peripheral units. Most dendrimers are composed of functional branches and luminous nuclei. The nuclei and branches are conveniently tunable.
Due to the particularity of the morphological structure of dendrimers, the synthesis method is different from ordinary linear polymers. The key to synthesis is to take appropriate methods to precisely control the growth of molecular chains in space. The current methods for synthesizing dendrimers are divided into the central core of dendrimers, a divergent synthesis method from inside to outside, and a convergent synthesis method from the outer layer of dendrimers from outside to inside.
- Divergent synthesis method: The divergent method starts from the zero generation first, that is, from the central nucleus which has one or more reaction points, and then reacts with the central nucleus using a unit with a branch structure, and thereafter, the first generation molecule is obtained. The functional group at the end of the branch of the first-generation molecule is converted into a functional group that can continue to react, and then the reaction with the branch unit reactant is repeated to obtain the second-generation molecule. By repeating the above two steps continuously, any high-algebra dendrimer can be obtained.
- Convergent synthesis method: The reaction starts from the part where the outermost structure of the dendrimer will be generated, and then reacts with the branch unit reactant to obtain the first generation molecule. Then activate the group and then react with the branch unit reactant to obtain the second generation molecule. By repeatedly activating the group and linking with the branch unit reactant in this way, a higher algebraic tree can be synthesized dendrimers.
- Sowinska Marta, Urbanczyk-Lipkowska Zofia. Advances in the chemistry of dendrimers [J]. New J. Chem., 2014, 38, 2168 - 2203.
- Boas U., Christensen J. B., Heegaard P. M. H. Dendrimers: design, synthesis and chemical properties [J]. J. Mater. Chem. , 2006, 16, 3785 - 3798.
- Satija Jitendra, Saib V. V. R. Mukherji Soumyo. Dendrimers in biosensors: Concept and applications [J]. J. Mater. Chem., 2011, 21, 14367 - 14386.