476144 Colloid Assembly Engineering

Sunday, November 13, 2016
Continental 4 & 5 (Hilton San Francisco Union Square)
Stefano Lazzari, Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA


Colloid Assembly plays a crucial role across a wide range of disciplines, and particularly finds applications in pharma, fine chemicals and solar cells (photovoltaics) industries. The assembly of colloids can be understood as the formation of structures arising from the combination of small (molecular or colloidal) entities. The structures being formed can either be the desired product (e.g. quantum dots[1]), or a problematic aggregate formation (e.g. solid formation in reactors that promotes clogging). The complex processes regulating the formation of such structures include nucleation, growth, aggregation and breakage, all of which depend on experimental conditions, e.g. temperature and shear rate[2]. Until significant improvements in the understanding of the aforementioned processes are made in the field of colloid science, we will not be able to i) fully exploit continuous flow technology for the production of pharmaceuticals and fine chemicals and ii) employ Colloid Assembly as a well-defined synthetic route for interesting structures (e.g. quantum dots, biomaterials, insulating materials).


I am comparing modeling predictions with experimental results to obtain fundamental, quantitative understanding of Colloid Assembly processes. The modeling techniques I am relying on include Population Balance Equations (PBE), Monte Carlo (MC) and Computational Fluid Dynamics (CFD) approaches. The combination of a modeling perspective with experimental results, obtained through literature and experimental data (e.g. from microscopy, scattering, spectroscopy) allows to discriminate among the possible occurring mechanisms and to identify their kinetic rates. The diversity of the present methodology allows me to appreciate the interplay of the ongoing physical mechanisms from different angles.

Personal background:

After receiving my bachelor and master degree at Politecnico di Milano in Italy, I pursued my doctoral studies at ETH Zurich, Switzerland, and I am currently a postdoc at MIT. During my PhD at ETH Zurich in the group of Prof. Massimo Morbidelli, I worked on several projects in the fields of polymers and colloids, combining experimental and modeling techniques to gain a phenomenological wide-angle view on the processes under investigation. In particular, I developed a significant experience in the field of PBE. This allowed me to approach problems such as the formation of multi-active polymer chains, the interplay between aggregation and coalescence of colloidal particles, as well as the aggregation and breakage of protein fibrils. Being awarded with two post-doctoral fellowships from the Swiss National Science Foundation, allowed me to join the group of Prof. Klavs Jensen at the MIT since April 2015. During my postdoctoral studies, I have been working along two main lines, namely i) developing a temperature dependent model for the formation of quantum dots and ii) developing a mathematical framework to describe solid formation and fouling.

Long term plan:

Capitalizing on the experiences gained during my PhD and Post-doctoral studies, my long-term vision focuses on pursuing several important questions persisting in the field of Colloid Assembly:

 i) Fully exploit Continuous Flow Technology for pharmaceutical and fine chemicals production:

  • How can Agglomeration and Clogging be prevented?
  • How can Crystallization in Flow be modeled?

ii) Improve Control over “Colloidal Materials” production:

  • How can the process of nanocrystal formation be optimized (e.g. size distribution)?
  • How can high-concentration aggregation be modeled?

iii) Develop a general mathematical framework to describe any assembly process

  • Which are the general kinetic rate expressions of such a model?
  • Which modeling techniques are best suited to build the model?

Research Interests:  

  • Colloid Assembly, Colloid Engineering
  • Solid Formation, Crystallization, Quantum Dots
  • Biodegradable Polymers, Polymer Reaction Engineering, Population Balance Equations

Teaching Interests:  

Having followed all the Chemical Engineering Classes at Politecnico di Milano and having some experience in this sense at ETH Zurich too, I would feel comfortable to teach any class in the Chemical Engineering curriculum. My personal inclinations and research interests drive me towards Colloid Stability, Polymer Reaction Engineering or Chemical Kinetics: in these courses, I could establish connections with my research, pointing out the outstanding challenges. Moreover, I would be able to involve students in possible research projects or in starting their master/PhD thesis in my research group.


[1] van Embden J., Chesman A.S.R, Jasieniak J.J., Chem. Mater. 2015, 27, 2246−2285

[2] Henry C., Minier JP, Lefèvre G., Adv. Colloid Interface Sci., 2012, 185-186, 34-76

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