Generation of strength in a drying film: How fracture toughness depends on dispersion properties.

@article{BirkBraun2017GenerationOS,
  title={Generation of strength in a drying film: How fracture toughness depends on dispersion properties.},
  author={Natalie Birk-Braun and Kamran Yunus and Eric J. Rees and Wilhelm Schabel and Alexander F. Routh},
  journal={Physical review. E},
  year={2017},
  volume={95 2-1},
  pages={
          022610
        }
}
The fracture toughness of colloidal films is measured by characterizing cracks which form during directional drying. Images from a confocal microscope are processed to measure the crack width as a function of distance from the crack tip. Applying theory for thin elastic films the fracture toughness is extracted. It is found that the fracture toughness scales with the particle size to the -0.8 power and that the critical energy release rate scales with the particle size to the -1.3 power. In… 
9 Citations

Figures and Tables from this paper

Fracture toughness of wet and dry particulate materials comprised of colloidal sized particles: role of plastic deformation.
TLDR
Understanding the fracture mechanisms that control the propagation of cracks through saturated, partially saturated and dry particulate materials comprised of colloidal sized particles provides additional insight into understanding drying cracks in paint, other coatings, ceramics and water treatment sludge.
Structural and mechanical properties of dried colloidal silica layers
Drying a colloidal suspension results in the formation of a more or less porous solid layer. This procedure is central to many applications such as sol-gel processes, the design of paints and
Highly porous layers of silica nanospheres sintered by drying: scaling up of the elastic properties of the beads to the macroscopic mechanical properties.
TLDR
The self-consistent scheme accurately predicts both bulk and shear moduli, with no adjustable parameter, provided the porosity is less than 35%, for layers composed of particles as small as 15 nm in diameter.
Nondestructive Characterization of Drying Processes of Colloidal Droplets and Latex Coats Using Optical Coherence Tomography
In this chapter, we review the applications of optical coherence tomography (OCT) on the nondestructive characterization of the drying processes of colloidal droplets and latex coatings. Employing
Transport dynamics of charged colloidal particles during directional drying of suspensions in a confined microchannel.
TLDR
An advection-diffusion model is developed to characterize the transport dynamics for unidirectional drying of a suspension consisting of charged particles in a confined Hele-Shaw cell and shows that confinement is equivalent to raising the effective concentration in the cell, and the drying front appears earlier and grows more rapidly.
Integrating optical coherence tomography with gravimetric and video analysis (OCT-Gravimetry-Video method) for studying the drying process of polystyrene latex system
TLDR
A system integrating optical coherence tomography with gravimetric and video analysis to non-destructively monitor the drying process of non-film-forming latexes consisting of hard polystyrene spheres over time finds that the particle size affects packing and cracking phenomena remarkably.

References

SHOWING 1-10 OF 25 REFERENCES
How to Reduce the Crack Density in Drying Colloidal Material
The drying of a colloidal dispersion can result in a gel phase defined as a porous matrix saturated in solvent. During the drying process, high mechanical stresses are generated. When these stresses
Plasticity and fracture in drying colloidal films.
TLDR
It is shown that although the deformation around a crack tip has some features of brittle fracture, only 20%-30% of the crack opening is relieved when it is unloaded, which suggests that a film's fracture toughness may be increased by decreasing the interparticle adhesion.
Cracking in drying latex films.
TLDR
The critical stress at cracking and the accompanying crack spacing is calculated, in general agreement with the observed values, by employing the stress-strain relation for a drying latex film along with the well-known Griffith's energy balance concept.
Flow and fracture in drying nanoparticle suspensions.
TLDR
It is shown that the growth of cracks is limited by the advancement of the compaction front, which is governed by a balance of evaporation and flow of fluid at the drying surface.
Wavy cracks in drying colloidal films
Fracture mechanics successfully predicts when cracks will grow. Describing the path that cracks follow, however, has remained difficult. The study of crack paths has recently focused on a single
Alternating crack propagation during directional drying.
TLDR
The propagation of fractures during the drying of a colloidal silica suspension confined in a vertical microtube is investigated, and the slow propagation of a fracture is followed by the rapid propagation of the other.
Imaging in-plane and normal stresses near an interface crack using traction force microscopy
TLDR
Traction force microscopy is extended to quantify the spatial distribution of all three components of the stress at the interface of two materials and extract the stress intensity factor.
Mixed mode cracking in layered materials
...
1
2
3
...