Direct writing of colloidal suspensions onto inclined surfaces: Optimizing dispense volume for homogeneous structures

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:597

Article

Winhard, Benedikt F.¹  Haugg, Stefanie²  Blick, Robert²  Schneider, Gerold A.¹  Furlan, Kaline P.^1,2 

[1] Hamburg Univ Technol, Inst Adv Ceram, Denickestr 15, D-21073 Hamburg, Germany

[2] Univ Hamburg, Ctr Hybrid Nanostruct, Luruper Chaussee 149, D-22607 Hamburg, Germany

关键词: Direct writing;    Self-assembly;    Inclined surface;    Colloidal suspension;    Photonic structure;    Surface capturing effect;    Confinement effect;   

DOI  :  10.1016/j.jcis.2021.03.017

来源: Elsevier

【 摘 要 】

Hypothesis: A process to fabricate structures on inclined substrates has the potential to yield novel applications for colloidal-based structures. However, for conventional techniques, besides the coffee ring effect (CRE), anisotropic particle deposition along the inclination direction (IE) is expected to occur. We hypothesize that both effects can be inhibited by reducing the dispense volume during printing by direct writing. Experiments: We combined an additive manufacturing technique, namely direct writing, with colloidal assembly (AMCA) for an automated and localized drop-cast of polystyrene and silica suspensions onto inclined surfaces. Herein, we investigated the influence of the substrate tilting angle and the dispense volume on the printing of colloids and the resulting structures' morphology. Findings: The results demonstrate that a reduction in the dispense volume hinders the CRE and IE for both particles' systems, even though the evaporation mode is different. For polystyrene, the droplets evaporated solely in stick-mode, enabling a surface capturing effect, while for silica, droplets evaporated in mixed stick-slip mode and a confinement effect was observed, which improved uniformity of the deposition. These findings were used to generate a model of the critical droplet radius needed to print homogeneous colloidal-based structures onto inclined substrates. (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

【 授权许可】

Free