1. Could you explain the significance of your article to the non-specialist? 

The surface properties of solid materials are of key importance in many different applications: Either undesired deposition leading to a loss of performance (e.g. blocking a porous filter) can be prevented, or specific binding of certain molecules or particles is desired (e.g. to an adsorber). Most polymeric materials with good mechanical stability and easy processing into suited (e.g. porous) geometries do not have those desired surface properties. Therefore, easy and controlled functionalization strategies are needed which allow the material's surface to be changed exclusively and to keep all bulk properties unchanged. The control of reactions by initiation with UV light has particular advantages, and the novel method is very well applicable to porous polymeric materials.

 

2. What has motivated you to conduct this work? 

The motivation for this study was two-fold. As chemists we explore the potential of reaction mechanisms, which are known to proceed very efficiently in solutions, for surface modifications which should be well-controlled and easy to apply to different base materials. As materials scientists, we are interested in functional polymeric materials prepared via controlled surface modifications, and this leads us to advanced or completely novel properties of membranes, adsorbers, sensors or biomaterials. The developed method is a significant improvement as compared with existing photo-grafting methods, especially when using highly reactive monomer mixtures. It is therefore very promising to apply this method for complicated surface functionalizations.

3. Where do you see this work developing in the future?                                             

Currently we are using the novel method for the synthesis of thin layers (about 10 to 20 nm thick) of molecularly imprinted polymers (MIPs - "plastic antibodies") on porous supports such as microfiltration membranes and porous particles. For such functionalizations, highly reactive mixtures containing a high content of crosslinker monomers are used. Therefore it is a particular challenge to confine the functionalization reaction to the surface, and this is possible with the novel method. However, this method can (and will) also be used for the preparation of "tailored" membrane adsorbers with three-dimensional grafted polymer binding layers. Other applications, including industrial surface modification processes, can be foreseen. It should be mentioned that the photo-initiation principle has the additional benefit that lateral structures can be produced using patterned UV irradiation.

4. Are there any particular challenges facing future research in this area?  

The challenge in our field is to combine increasingly sophisticated and miniaturized morphologies of solid materials (e.g. micro- and nanoporous polymer particles and membranes or microfluidic systems made from polymer) with highly specific functions. Here, the tailoring of the surfaces plays the key role. Therefore, well-controlled surface functionalization methods, which are easy and robust at the same time, are enabling technologies to prepare complex technical systems