Stabilization and Functionalization of Nanoparticles
Due to their extremely high specific surface area, nanoparticles strongly tend to agglomerate. For many applications it is however essential to handle them in individual form, often as single particles dispersed in a liquid medium. Therefore, the stabilization of nanoparticles against agglomeration via a controlled chemical modification of the particle surface is a main research focus of our group. Especially the use of small organic molecules, termed ligands, is explored, as highly stable dispersions with minimum amounts of the organic stabilizer can be obtained.
Beyond the concept of stabilization, it is also possible to specifically bind molecules to the particle surface to tailor the particle properties and enable novel functions and properties. For example, antibodies can selectively be anchored to magnetic nanoparticles, which is investigated within the framework of the Collaborative Research Center SFB 578. Even the optical properties of nanoparticles can be altered by functionalization, as is shown in the image.
Functionalized TiO2-nanoparticles (a) as dried powder and (b) in dispersion after in situ-functionalization with dopamine; (c) as dried powder and (d) in dispersion after in situ-functionalization with glycine. Right: schematic of a dopamine-stabilized nanoparticle.
Publications:
- I.-C. Masthoff, F. David, C. Wittmann, G. Garnweitner, “Functionalization of magnetic nanoparticles with high-binding capacity for affinity separation of therapeutic proteins”, Journal of Nanoparticle Research 2014, 16, Art. No. 2164. Abstract
- Grote C, Cheema TA, Garnweitner G. “Comparative study of ligand binding during the postsynthetic stabilization of metal oxide nanoparticles, Langmuir. 2012, 28, 14395-14404. Abstract
- C. Grote, K. J. Chiad, D. Vollmer, G. Garnweitner, “Unspecific ligand binding yielding stable colloidal ITO- nanoparticle dispersions”, Chemical Communications 2012, 48, 1464-1466. Abstract.
- G. Garnweitner, “Small molecule stabilization: A novel concept for the stabilization of small inorganic nanoparticles”, in: L. Segewicz and M. Petrowsky (Eds.), “Polymer Aging, Stabilizers and Amphiphilic Block Copolymers”, Nova Science Publishers, 2010.
- G. Garnweitner, H. O. Ghareeb, C. Grote, “Small-molecule in situ stabilization of TiO2 nanoparticles for the facile preparation of stable colloidal dispersions”, Colloids and Surfaces Part A: Physicochemical and Engineering Aspects 2010, 372, 41-47.
- G. Garnweitner, L. M. Goldenberg, O. V. Sakhno, M. Antonietti, M. Niederberger, J. Stumpe, “Large-scale synthesis of organophilic zirconia nanoparticles and their application in organic-inorganic nanocomposites for efficient volume holography”, Small 2007, 3, 1626-1632.
