Essay --

steps where addition of each iteration produces a higher generation of dendrimer (Tomalia and Frechet, 2001). The synthesis method used for dendrimer preparation permit almost entire control over the critical molecular design parameters such as size, shape, surface/interior chemistry, flexibility, and topology. The dendrimers can be synthesized by using three different approaches (Crespo et al., 2005). 1. Divergent approach 2. Convergent approach 3. Double stage convergent approach Divergent approach In this method, dendrimer grows outwards from a multifunctional core molecule towards periphery. As a result of this growth, each new iterative reaction is characterized by the generation of an exponentially increasing number of functional groups on the periphery and double the molecular weight than the previous layer (Vogtle et al., 1978). The reaction steps can be repeated to increase the size of dendrimers as required. Many problems occur from side reactions and incomplete reactions of the end groups that lead to structural defects. To prevent side reactions and for completion o...