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

Structural behavior of cylindrical polystyrene-block-poly(ethylene-butylene)-block-polystyrene (SEBS) triblock copolymer containing MWCNTs: on the influence of nanoparticle surface modification

Hasanabadi, Noushin ; Nazockdast, Hossein ; Gajewska, Bernadetta ; Balog, Sandor ; Gunkel, Ilja ; Bruns, Nico ; Lattuada, Marco

In: Macromolecular Chemistry and Physics, 2017/218/22/n/a-n/a

In this work, the influence of carbon nanotubes (CNTs) on the self-assembly of nanocomposite materials made of cylinder-forming polystyrene-block-poly(ethylene- butylene)-block-polystyrene (SEBS) is studied. CNTs are modified with polystyrene (PS) brushes by surface-initiated atom transfer radical polymerization to facilitate both their dispersion and the orientation of neighboring PS domains...

Université de Fribourg

Rheological characterization of nanostructured material based on Polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS) block copolymer: Effect of block copolymer composition and nanoparticle geometry

Hasanabadi, Noushin ; Nazockdast, Hossein ; Balog, Sandor ; Lattuada, Marco

In: Composites Science and Technology, 2017, vol. 149, no. Supplement C, p. 192–206

Block copolymer (BCP) nanocomposite systems are of broad interest; however, reports on the role of nanoparticles on microphase separation behavior are rare. The goal of present study is to investigate the preparation of composite nanostructured materials containing Multi-Walled Carbon Nanotubes (MWCNTs) or graphene nanoplates. BCP nanocomposites based on the linear triblock copolymer, ...

Université de Fribourg

Bioinspired stimuli-responsive color-changing systems

Isapour, Golnaz ; Lattuada, Marco

In: Advanced Materials, 2018, vol. 30, no. 19, p. 1707069

Stimuli-responsive colors are a unique characteristic of certain animals, evolved as either a method to hide from enemies and prey or to communicate their presence to rivals or mates. From a material science perspective, the solutions developed by Mother Nature to achieve these effects are a source of inspiration to scientists for decades. Here, an updated overview of the literature on...

Université de Fribourg

Effect of aging on thermal conductivity of fiber-reinforced aerogel composites: An X-ray tomography study

Iswara, Subramaniam ; Griffa, Michele ; Kaufmann, Rolf ; Beltran, Mario ; Huber, Lukas ; Brunner, Samuel ; Lattuada, Marco ; M.Koebel, Matthias ; Malfait, Wim J.

In: Microporous and Mesoporous Materials, 2019, vol. 278, p. 289–296

Silica aerogels display an ultra-low thermal conductivity (λ) and are used as thermal superinsulators. Here, we study the influence of aging and drying processes on the microstructure and thermal conductivity of fiber-reinforced silica aerogel composites. Glass wool-silica gel composites were aged for variable times, hydrophobized, and dried either at ambient pressure or from supercritical...

Université de Fribourg

Reinforced and superinsulating silica aerogel through in situ cross-linking with silane terminated prepolymers

Iswar, Subramaniam ; Snellings, Geert M. B. F. ; Zhao, Shanyu ; Erni, Rolf ; Bahk, Yeon Kyoung ; Wangd, Jing ; Lattuada, Marco ; Koebel, Matthias M. ; Malfait, Wim J.

In: Acta Materialia, 2018, vol. 147, p. 322–328

Silica aerogels have only half the thermal conductivity of conventional insulation, but their application potential is limited by the poor mechanical properties. The fragility arises from the thin necks between the silica nanoparticle building blocks. Here, we produce strong silica aerogels through co-gelation of the polyethoxydisiloxane precursor with a variety of silane terminated...

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

Effect of clustering on the heat generated by superparamagnetic iron oxide nanoparticles

Lattuada, Marco

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 1, p. 39–42

Magnetic nanoparticles have been the subject of enormous investigations for their potential use as cancer treatment via hyperthermia. This is due to their ability to generate heat when exposed to an external magnetic field oscillating at sufficiently high frequency. There are many different parameters that need to be considered when designing the optimal nanoparticle formulation for...

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...