Yug C Saraswat1, Fatma Ibis2, Laura Rossi3, Luigi Sasso4, Huseyin Burak Eral5, Paola Fanzio4. 1. Process & Energy Laboratory, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, the Netherlands. Electronic address: yug@yugdecor.com. 2. Process & Energy Laboratory, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, the Netherlands. Electronic address: F.Ibis-1@tudelft.nl. 3. Department of Chemical Engineering, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, the Netherlands. Electronic address: L.Rossi@tudelft.nl. 4. University of Technology, Dep. Precision and Microsystems Engineering, Mekelweg 2, 2826 CD Delft, the Netherlands. 5. Process & Energy Laboratory, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, the Netherlands. Electronic address: H.B.Eral@tudelft.nl.
Abstract
HYPOTHESIS: Our ability to dictate the colloid geometry is intimately related to self-assembly. The synthesis of anisotropic colloidal particles is currently dominated by wet chemistry and lithographic techniques. The wet chemical synthesis offers limited particle geometries at bulk quantities. Lithographic techniques, on the other hand, provide precise control over the particle shape, although at lower yields. In this respect, two-photon polymerization (2PP)1 has attracted growing attention due to its ability to automatically fabricate complex micro/nano structures with high resolution. EXPERIMENTS: We manufacture precisely designed colloids with sizes ranging from 1 µm to 10 µm with 2PP and optimize the process parameters for each dimension. Moreover, we study the shape dependent Brownian motion of these particles with video microscopy and estimate their diffusion coefficients. FINDINGS: We observe that increasing the geometrical anisotropy leads to a pronounced deviation from the analytically predicted diffusion coefficient for disks with a given aspect ratio. The deviation is attributed to stronger hydrodynamic coupling with increasing anisotropy. We demonstrate, for the first time, 2PP manufacturing of colloids with tailored geometry. This study opens synthesis of colloidal building blocks to a broader audience with limited access to cleanrooms or wet-chemistry know-how.
HYPOTHESIS: Our ability to dictate the colloid geometry is intimately related to self-assembly. The synthesis of anisotropic colloidal particles is currently dominated by wet chemistry and lithographic techniques. The wet chemical synthesis offers limited particle geometries at bulk quantities. Lithographic techniques, on the other hand, provide precise control over the particle shape, although at lower yields. In this respect, two-photon polymerization (2PP)1 has attracted growing attention due to its ability to automatically fabricate complex micro/nano structures with high resolution. EXPERIMENTS: We manufacture precisely designed colloids with sizes ranging from 1 µm to 10 µm with 2PP and optimize the process parameters for each dimension. Moreover, we study the shape dependent Brownian motion of these particles with video microscopy and estimate their diffusion coefficients. FINDINGS: We observe that increasing the geometrical anisotropy leads to a pronounced deviation from the analytically predicted diffusion coefficient for disks with a given aspect ratio. The deviation is attributed to stronger hydrodynamic coupling with increasing anisotropy. We demonstrate, for the first time, 2PP manufacturing of colloids with tailored geometry. This study opens synthesis of colloidal building blocks to a broader audience with limited access to cleanrooms or wet-chemistry know-how.
Authors: Xiaohong Liu; Mohammad-Amin Moradi; Tom Bus; Michael G Debije; Stefan A F Bon; Johan P A Heuts; Albert P H J Schenning Journal: Angew Chem Int Ed Engl Date: 2021-11-17 Impact factor: 16.823