A new method for the analysis of compaction processes in high-porosity agglomerates

Abstract

Mechanical properties of high-porous microscopic agglomerates have been investigated. For this purpose we installed an atomic force microscope (AFM) cantilever in a scanning electron microscope (SEM) using a nanomanipulator. The nanomanipulator is piezoelectric controlled with increments of 5 nm in the rotational and 0.5 nm in the translational direction. Thus, this tool allows the precise positioning and movement of an AFM cantilever under SEM observation. Depending on the spring constant of the cantilever and the step size of the motion-both quantities determining the sensitivity of the instrument-different aspects of the deformation of dust-aggregate structures, e.g., the behaviour of single particle chains, can be analysed.

Mechanical Properties of Highly Porous Super Liquid‐Repellent Surfaces

“…These agglomerates and strings can act like a glue, connecting the tip with the still intact parts of the superamphiphobic layer. [48] The maximum adhesion force corresponds to the main detachment event of the tip from the [49] With r tip = 10 nm we estimate a van der Waals adhesion of 4 nN. This agrees with the measured forces.…”

“…They partially assemble into agglomerates which are connected by strings of particles. The fragile network was stabilized by deposition of a silica shell using chemical vapor deposition (CVD) of tetraethyl orthosilicate (TEOS) for 24,48, and 72 h. These samples are referred to as coated soot. The thickness of the deposited silica layer increased with CVD time and ranged from 20-35, 35-71, and 60-100 nm for 24,48, and 72 h, respectively.…”

“…The fragile network was stabilized by deposition of a silica shell using chemical vapor deposition (CVD) of tetraethyl orthosilicate (TEOS) for 24,48, and 72 h. These samples are referred to as coated soot. The thickness of the deposited silica layer increased with CVD time and ranged from 20-35, 35-71, and 60-100 nm for 24,48, and 72 h, respectively. The coated soot was sintered at 600 °C, 800 °C, 1000 °C, or 1150 °C for 3 h. Thereby, the carbon was completely combusted and the sintered samples are therefore referred to as soot-templated silica.…”

Cohesive, frictional powders: contact models for tension

“…Since effects like liquid and possibly permanent solid bridges are not subject of the present study, we refer to the detailed literature, see Refs. [5,9,19,20,24,68,69,74,87,88,90] and references therein.…”

“…[8,20,30] and references therein. Even though contacts can have a temperature and time-dependent behavior as during sintering [46,50,51], this will not be the issue of the present study.…”