Controlled radical polymerization, grafting and hierarchical imprinting

Aim

One important drawback of the present imprinting technology is the lack of means to produce "monoclonal" imprinted polymers with a high concentration of uniform high energy binding sites. This project investigates approaches to overcome this problem targeting biologically relevant target molecules.

Approach

Two approaches to reduce imprinted network polyclonality is being investigated by:

1. Controlled radical polymerization (CRP) via chain transfer agents (RAFT) or iniferters of a standard MIP prepolymerization mixture.
2. Combination of grafting under CRP conditions and support removal to produce thin walled materials with uniformly accessible sites.

Results

We reported on "grafting from" techniques for the synthesis of MIP composite materials with improved kinetic properties. Recently we investigated the use of RAFT agents as another means of achieving CRP. The materials could be prepared in short time and exhibited superior mass transfer properties compared to the traditional imprinted bulk monoliths or materials prepared without the polymerization control through RAFT agents.
Furthermore, the concept of hierarchical imprinting has been developed by our group (DFG Se777/5-2). Typically an inorganic material serves as a template for the synthesis of organic materials of defined morphology. Thus, porous silica has been used as a sacrificial template for the synthesis of mesoporous organic polymer networks (Fig.24). Recently we have preliminary assessed the combination of the grafting approach, CRP and templated material synthesis in order to generate defined nanostructures.

Figure 24: The procedure for generating thin walled materials via "grafting" from CRP and template synthesis

Funding

DFG Se7778-1 (2005-2008)

Contact

Dipl.-Chem. Carla Aureliano
C.Aureliano@infu.uni-dortmund.de
Phone: +49-(0)231-755-7065

Dr. rer. nat. Eric Schillinger
E.Schillinger@infu.uni-dortmund.de
Phone: +49-(0)231-755-7065

Paper

1. Sellergren, B.; Titirici, M.-M. (2004):
   "Hierarchical Imprinting using crude solid phase synthesis products as templates" Analytical and Bioanalytical Chemistry, 378, 1913-1921.

2. Titirici, M.-M.; Sellergren, B. (2006):
   "Thin molecularly imprinted polymer films via radical addition fragmentation chain transfer polymerization" Chem. Mater., 18, 1773-1779.