Université de Fribourg

Effect of aging on silica aerogel properties

Iswar, Subramaniam ; Malfait, Wim J. ; Balog, , Sandor ; Winnefeld, Frank ; Lattuada, Marco ; Koebel, Matthias M.

In: Microporous and Mesoporous Materials, 2017, vol. 241, p. 293–302

Silica aerogels’ unique physical and chemical properties make them fascinating materials for a wide variety of applications. In addition to hydrophobization by silylation, aging is very important in the synthesis of silica aerogel by ambient pressure drying. Here we systematically study the effect of aging on the physico-chemical properties of silica aerogel with emphasis on ambient dried...

Université de Fribourg

Theranostic body fluid cleansing: rationally designed magnetic particles enable capturing and detection of bacterial pathogens

Lattuada, Marco ; Ren, Q. ; Zuber, F. ; Galli, M. ; Bohmer, N. ; Matter, M. T. ; Wichser, A. ; Bertazzo, S. ; Pier, G. B. ; Herrmann, I. K.

In: Journal of Materials Chemistry B, 2016, vol. 4, no. 44, p. 7080–7086

We report on theoretical and experimental considerations on bacteria capturing and enrichment via magnetic separation enabling integrated diagnosis and treatment of blood stream infections. We show optimization of carrier-pathogen interactions based on a mathematical model followed by an experimental proof-of-concept study along with investigations on the process safety.

Université de Fribourg

A lock-in-based method to examine the thermal signatures of magnetic nanoparticles in the liquid, solid and aggregated states

Monnier, Christophe A. ; Lattuada, Marco ; Burnand, David ; Crippa, F. ; Martinez-Garcia, J. C. ; Hirt, A. M. ; Rothen-Rutishauser, B. ; Bonmarin, M. ; Petri-Fink, Alke

In: Nanoscale, 2016, vol. 8, no. 27, p. 13321–13332

We propose a new methodology based on lock-in thermography to study and quantify the heating power of magnetic nanoparticles. Superparamagnetic iron oxide nanoparticles exposed to a modulated alternating magnetic field were used as model materials to demonstrate the potency of the system. Both quantitative and qualitative information on their respective heating power was extracted at high...

Université de Fribourg

Universal breakup of colloidal clusters in simple shear flow

Harshe, Yogesh M. ; Lattuada, Marco

In: The Journal of Physical Chemistry B, 2016, vol. 120, no. 29, p. 7244–7252

We have studied the long-term dynamics of shear-induced breakage of individual colloidal clusters, covering a wide range of fractal dimensions, using Stokesian dynamics. We found that the time evolution of the normalized average size of the fragments generated by the breakup process could be scaled using a unique dimensionless time defined by multiplying the real time with the cluster...

Université de Fribourg

Population-balance description of shear-induced clustering, gelation and suspension viscosity in sheared DLVO colloids

Lattuada, Marco ; Zaccone, Alessio ; Wu, Hua ; Morbidelli, Massimo

In: Soft Matter, 2016, vol. 12, no. 24, p. 5313–5324

Application of shear flow to charge-stabilized aqueous colloidal suspensions is ubiquitous in industrial applications and as a means to achieve controlled field-induced assembly of nanoparticles. Yet, applying shear flow to a charge-stabilized colloidal suspension, which is initially monodisperse and in quasi-equilibrium leads to non-trivial clustering phenomena (and sometimes to a gelation...

Université de Fribourg

Fractal-like structures in colloid science

Lazzari, S. ; Nicoud, L. ; Jaquet, B. ; Lattuada, Marco ; Morbidelli, M.

In: Advances in Colloid and Interface Science, 2016, vol. 235, p. 1–13

The present work aims at reviewing our current understanding of fractal structures in the frame of colloid aggregation as well as the possibility they offer to produce novel structured materials. In particular, the existing techniques to measure and compute the fractal dimension df are critically discussed based on the cases of organic/inorganic particles and proteins. Then the aggregation...

Université de Fribourg

The role of mass and length in the sonochemistry of polymers

Schaefer, Mark ; Icli, Burcak ; Weder, Christoph ; Lattuada, Marco ; Kilbinger, Andreas F. M. ; Simon, Yoan C.

In: Macromolecules, 2016, vol. 49, no. 5, p. 1630–1636

The ultrasound-induced cleavage of macromolecules has become a routine experiment in the emerging field of polymer mechanochemistry. To date, it has not been conclusively proven whether the molecular weight of a polymer or its contour length is the determining factor for chain scission upon ultrasonication. Here we report comparative experiments that confirm unequivocally that the contour length...

Université de Fribourg

Nanoparticle colloidal stability in cell culture media and impact on cellular interactions

Moore, Thomas L. ; Rodriguez-Lorenzo, Laura ; Hirsch, Vera ; Balog, Sandor ; Urban, Dominic ; Jud, Corinne ; Rothen-Rutishauser, Barbara ; Lattuada, Marco ; Petri-Fink, Alke

In: Chemical Society Reviews, 2015, vol. 44, no. 17, p. 6287–6305

Nanomaterials are finding increasing use for biomedical applications such as imaging, diagnostics, and drug delivery. While it is well understood that nanoparticle (NP) physico-chemical properties can dictate biological responses and interactions, it has been difficult to outline a unifying framework to directly link NP properties to expected in vitro and in vivo outcomes. When introduced to...

Université de Fribourg

Magnetic microreactors for efficient and reliable magnetic nanoparticle surface functionalization

Digigow, Reinaldo G. ; Dechézelles, Jean-François ; Kaufmann, J. ; Vanhecke, Dimitri ; Knapp, H. ; Lattuada, Marco ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: Lab on a Chip, 2014, p. -

Microreactors have attracted wide attention in the nano- and biotechnology fields because they offer many advantages over standard liquid phase reactions. We report the development of a magnetic microreactor for reliable, fast and efficient surface functionalization of superparamagnetic iron oxide nanoparticles (SPIONs). A comprehensive study of the development process in terms of setup, loading...

Université de Fribourg

Insertion of Nanoparticle Clusters into Vesicle Bilayers

Bonnaud, Cécile ; Monnier, Christophe A. ; Demurtas, Davide ; Jud, Corinne ; Vanhecke, Dimitri ; Montet, Xavier ; Hovius, Ruud ; Lattuada, Marco ; Rothen-Rutishauser, Barbara ; Petri-Fink, Alke

In: ACS Nano, 2014, vol. 8, no. 4, p. 3451–3460

A major contemporary concern in developing effective liposome–nanoparticle hybrids is the present inclusion size limitation of nanoparticles between vesicle bilayers, which is considered to be around 6.5 nm in diameter. In this article, we present experimental observations backed by theoretical considerations which show that greater structures can be incorporated within vesicle membranes by...