Synthesis, Surface Modification and In Situ Analysis

The development of nanostructured materials for functional devices such as solar and fuel cells or pigment coatings requires particles with high crystallinity, tuneable size and shape distribution and colloid stability. Such high control at the nanoscala has been achieved so far by a trial-and-error approach, whereby our group aims for a rational design of multifunctional materials.

Such materials can often be economically synthesized under hydro- and solvothermal conditions at moderate to high temperatures and autogenous pressure. A deep research interest is the synthesis of mesocrystals, defined as superstructures composed of ordered arrangements of nano- or micro-sized building blocks (panel a). During the formation process, various closely-entangled physico-chemical processes involving nucleation, growth, aggregation, and in some cases, growth by particle aggregation, simultaneously occur. Processes taking place in broad size ranges from the molecular to micron level, and time-scales ranging from seconds to hours further complicate the development of a mechanistic understanding of particle formation.

One possible strategy to tackle this problem is the simultaneous implementation of complementary in situ analytical and spectroscopic techniques to monitor the evolution of synthesis solutions in real time. With this background in mind, a 1.5L solvothermal reactor with an automatic heating and cooling jacket, sampling system, precursor adding system and connections allowing for up to 4 simultaneous in situ measurement techniques including photoluminescence, UV/Vis, FTIR and Raman spectroscopy, dynamic light scattering (DLS), as well as turbidity, oxygen concentration, and conductivity measurements was designed (panel b).

Finally, the colloidal stability of suspensions is an important pre-requisite to ensure that the properties of the individual particles are extended to their ensembles in liquid phase. Methods based on steric or electrostatic stabilization are developed to control liquid-solid interfaces to achieve both stable suspensions and control the self-assembly of primary building blocks (panel c).

Publications:

Güldenpfennig, M. Distaso, W. Peukert “In situ investigation of the aging process of hydroxycarbonates precursor phases of Cu/ZnO catalysts for methanol synthesis”, Chem. Eng. J. 2019, 369, 996-1004.
Trzenschiok, M. Distaso, W. Peukert “A new approach for the stabilization of amorphous drug nanoparticles during continuous antisolvent precipitation” Chem. Eng. J. 2019, 361, 428-438.
Embrechts, M. Kriesten, K. Hoffmann, W. Peukert, M. Hartmann, M. Distaso* “Elucidation of the formation mechanism of metal-organic frameworks via in-situ Raman and FTIR spectroscopy under solvothermal conditions” J. Phys. Chem. C 2018, 122, 12267-12278.
Distaso*, G. Bertoni, S. Todisco, S. Marras, V. Gallo, L. Manna, W. Peukert “Interplay of Internal Structure and Interfaces on the Emitting Properties of Hybrid ZnO Hierarchical Particles” ACS Appl. Mater. Interfaces 2017, 9, 15182-15191.
Distaso*, O. Zhuromskyy, B. Seemann, L. Pflug, M. Mačković, E. Encina, R. Klupp Taylor, R. Müller, G. Leugering, E. Spiecker, U. Peschel, W. Peukert “Interaction of light with Hematite hierarchical structures: experiments and simulations” J. Quant. Spectr. Rad. Transf. 2017, 189, 369-382.
Distaso*, B. Apeleo Zubiri, A. Mohtasebi, A. Inayat, M. Dudak, Petr Kocí, B. Butz, R. Klupp Taylor, W. Schwieger, E. Spiecker, W. Peukert “Three-dimensional and quantitative reconstruction of non-accessible internal porosity in hematite nanoreactors using 360 ° electron Tomography” Microporous and Mesoporous Materials 2017, 246, 207-214.
Klaumuenzer, M. Distaso, J. Huebner, M. Mackovic, E. Spiecker, C. Kryschi, W. Peukert “ZnO superstructures via oriented aggregation initiated in a block copolymer melt” CrystEngComm 2014, 16, 1502
M. Distaso*, D. Segets, R. Wernet, R. Klupp Taylor, W. Peukert “Tuning the size and the optical properties of ZnO mesocrystals synthesized under solvothermal conditions” Nanoscale 2012, 4,