Schematic diagram of the construction of multi-layered films by using polydopamine coating as the interlayer (Picture/WANG Jinqing et al.)

 

Progress in the research on material surface modification and preparation of nanocomposite films has been achieved by the research group of Polymer Tribology of the State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics (LICP), CAS.

Surface and interface have always been a research focus in nanoscience. The properties of materials can be improved by tuning the surface microstructure and composition. Currently, there exist many techniques for surface modification. However, the development of a facile method with strong applicability has still been a challenge.

What's encouraging is that the polydopamine material recently reported has made the development of such method possible. Polydopamine possesses two distinctive characteristics: firstly, it can be attached to almost all surfaces to form polydopamine coating; secondly, there is a great quantity of functional groups on the surface of coating thus formed. The functional groups can undergo a series of reactions, which create the conditions for the further modification.

Researchers of the State Key Laboratory of Solid Lubrication have constructed a series of polydopamine-based composite films on various material surfaces, including single crystalline silicon wafer, aluminium sheet and some polymer substrates by using polydopamine as the platform. They have investigated in detail the relationship between the micro-structure and the properties (tribological property, corrosion resistance, biocompatibility, etc.) of the films as well.

It has been found that the as-prepared multi-layered films and substrates were combined through covalent bonding due to the introduction of polydopamine. And the film was connected between layers through covalent bonding as well. The films show greatly enhanced stability, excellent tribological property, corrosion resistance and biocompatibility.

The research results were published in The Journal of Physical Chemistry C ( 2009, 113: 20429-20434 ), Applied Surface Science ( 2009, 256: 894-899 ) , Colloids and Surfaces B: Biointerfaces ( 2010, 76: 123-127 ) , Progress in Organic Coatings ( 2010, 68: 244-247 ) and Surface and Interface Analysis (DOI 10.1002/sia.3631).

The work was supported by the National Natural Science Foundation of China and Hundred Talents Program of the CAS.