Polymer-grafted nanoparticles

Environmentally Friendly Synthesis of Polymer-Grafted Nanoparticles... 

However, scale-up synthesis of polymer-grafted nanoparticles was hardly achieved, because complicated reaction processes, such as centrifugation, filtration, and solvent extraction, are required for the synthesis and isolation of polymer-grafted nanoparticles, and a lot of waste solvent is generated. 

In an organic solvent system, after the reaction, the purification and isolation of the resulting nanoparticles was achieved by troublesome procedures, such as filtration and centrifugation as mentioned above. Therefore, the scale-up synthesis of polymer-grafted nanoparticles was hardly achieved and large quantities of waste solvent result. 

On the contrary, in ionic liquids, the isolation and purification after the graft polymerization was easily achieved, because untreated monomer can be removed under high vacuum as well as solvent-free dry-system Therefore, it is expected that we can achieve scale-up and environmentally friendly synthesis of polymer-grafted nanoparticles by use of ionic liquid. 

Process (2) is one the most favorable for the preparation of polymer-grafted nanoparticles with a higher percentage of grafting. We can control the molecular weight and number of grafted polymer chains by use of surface initiated living polymerization as mentioned... 

Ungrafted polymer precipitated because the polymer is insoluble in ionic liquid. After the graft polymerization, polymerization was terminated by the addition of a small amount of methanol. Therefore, ionic liquid contains polymer-grafted nanoparticles, unreacted monomer, ungrafted polymer, and methanol. The precipitate, containing polymer-grafted nanoparticle and ungrafted polymer, was removed by filtration. 

Therefore, the reduction of waste solvent and environmentally friendly scale-up synthesis of polymer-grafted nanoparticles can be achieved by use of ionic liquid as a reaction solvent. 

The reduction of waste solvent was achieved by use of ionic liquid as reaction solvent, because unreacted monomer could be removed under high vacuum after the reaction and the reuse of ionic liquid was easily achieved. Therefore, the graft polymerization onto nanoparticle surface in ionic liquid enables environmentally friendly scale-up synthesis of polymer-grafted nanoparticles. 

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