Since beginning of the project the following results were achieved:
Silica particles of various sizes from submicrometer to several micrometer were obtained, flat and wrinkled stamps with different amplitude/period ratios were generated and di-valent particles were prepared using both wrinkled stamps and flat stamps via sandwich printing. For the polymer particles di-valent particles with two opposite chemical functionalities of patches – basic and acidic – were obtained.
Moreover, tetra- and multivalent patchy silica particles were fabricated.
A specially designed microcontact printing cell for the precise and controllable use of the centrifugal force was developed in the collaboration with the company LUM, Berlin, Germany and will be tested in the nearest future. By using this device it is possible to align the patch printing exactly on the pole position. Control of rotation speed and acceleration allow for excellent control not only over the centrifugal force applied for printing but also to define the rate of its evolution with time and thus investigate rheological phenomena during the printing procedure.
Optical microscopy was applied to quantify the formation of the particulate superstructures in the suspensions of di-valent particles in different solvents. First results are very promising, however, the yield of these superstructures has to be improved. In addition, Nanoparticle Tracking Analysis (NTA) technique (Malvern NanoSight NS300 Instrument) was applied for measurements in the suspensions of di-valent particles. This method enables simultaneously direct observation and measurement of diffusion events for each particle/particulate structure in the system.
Finally, first successful experiments on the creation of linear superstructures of di-valent particles (cyclodextrin modified magnetite nanoparticles) were carried out.
