TY  - JOUR
AU  - Schlenk, Mathias
AU  - Hofmann, Eddie
AU  - Seibt, Susanne
AU  - Rosenfeldt, Sabine
AU  - Schrack, Lukas
AU  - Drechsler, Markus
AU  - Rothkirch, Andre
AU  - Ohm, Wiebke
AU  - Breu, Josef
AU  - Gekle, Stephan
AU  - Förster, Stephan
TI  - Parallel and Perpendicular Alignment of Anisotropic Particles in Free Liquid Microjets and Emerging Microdroplets
JO  - Langmuir
VL  - 34
IS  - 16
SN  - 1520-5827
CY  - Washington, DC
PB  - ACS Publ.
M1  - FZJ-2019-00768
SP  - 4843 - 4851
PY  - 2018
AB  - Liquid microjets play a key role in fiber spinning, inkjet printing, and coating processes. In all of these applications, the liquid jets carry dispersed particles whose spatial and orientational distributions within the jet critically influence the properties of the fabricated structures. Despite its importance, there is currently no knowledge about the orientational distribution of particles within microjets and droplets. Here, we demonstrate a microfluidic device that allows to determine the local particle distribution and orientation by X-ray scattering. Using this methodology, we discovered unexpected changes in the particle orientation upon exiting the nozzle to form a free jet, and upon jet break-up into droplets, causing an unusual biaxial particle orientation. We show how flow and aspect ratio determine the flow orientation of anisotropic particles. Furthermore, we demonstrate that the observed phenomena are a general characteristic of anisotropic particles. Our findings greatly enhance our understanding of particle orientation in free jets and droplets and provide a rationale for controlling particle alignment in liquid jet-based fabrication methodologies.
LB  - PUB:(DE-HGF)16
C6  - pmid:29528234
UR  - <Go to ISI:>//WOS:000431088500015
DO  - DOI:10.1021/acs.langmuir.8b00062
UR  - https://juser.fz-juelich.de/record/859962
ER  -