Tethering of Substrate within Polymer Particle

The introduction of functional handles to direct the encapsulation of small molecules can be readily achieved using the self-assembly of polymer di- or tii block copolymers, given the facile introduction of reactive handles into the copolymerization strategy. One advantage of this method is that the loading of the nanoparticle can be readily tailored by the designed synthesis of the parent particle. 

In analogy to the crosslinking of polymer nanoparticles, the functionalization of polymer nanoparticles can be achieved at various different locations, thereby allowing for the tailoring 

More specifically, the synthesis of micelles as a scaffold for the formation of metal particles has been achieved (Loginova et al, 2004). This has been demonstrated very effectively by the group of Bronstein, who has utilized polystyrene as a reactive polymer to functionalize with molybdenum hexacarbonyl using UV radiation followed by reaction with H2S to afford MoS encapsulated micelles. In related work Chu has reported the use of block copolymer micelles as template s for the formation of hollow molybdenum spheres whose diameter is equivalent to the size of the micellar cores (about 5 nm) (Lui et al, 2000). More recently Xie and coworkers have used micelle-assisted fabrication of necklace-shaped molybdenum disulfide nanospheres (Xiong et al, 2003). In this work, the authors used the aggregation-driven transformation of surfactants at low temperatures to form a necklace-shaped assembly of amorphous M0S3 nanospheres. 

Lansalot and coworkers very recently reported a new strategy for the synthesis of iron-oxide nanoparticles using a functional monomer approach (Joumaa et al, 2008). By selectively designing a functional monomer with a pendant reactive phosphate group, which can selectively interact with the iron particles, the successful incorporation of these particles into the polymer nanoparticles was achieved. This monomer was utilized as a surfmer and displayed a phosphate group at one extremity and a polymerizable methacrylic functionality at the other one that are separated by a short poly(ethylene) glycol spacer. 

One key example of the utilization of functional monomer was that reported by Sutherland and coworkers where they utilized the suspension polymerization of a quantum-dot-functionalized monomer for the synthesis of hybrid and highly fluorescent polystyrene particles (O Brien et al, 2003). 

---