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) 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.
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http://dx.doi.org/10.1016/j.jcis.2019.12.035 | DOI Listing |
Adv Mater
January 2025
Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Metal halide perovskite solar cells (PSCs) have emerged as one of the most promising candidates for next-generation photovoltaic technologies. However, perovskite films deposited by blade-coating usually exhibit inferior film morphology compared to those fabricated by spin-coating, which hinders the power conversion efficiency (PCE) and stability of the scalable perovskite solar modules (PSMs). Herein, ellipsoidal colloids are tailored in the perovskite precursor solution by incorporating perovskite colloids and polymer additives.
View Article and Find Full Text PDFNatl Sci Rev
February 2025
Institute of Nanoscience and Applications, Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Colloidal quantum dots (QDs) are solution-processable semiconductor nanocrystals with favorable optoelectronic characteristics, one of which is their multi-excitonic behavior that enables broadband polychromatic light generation and amplification from monodisperse QDs. However, the practicality of this has been limited by the difficulty in achieving spatial separation and patterning of different colors as well as the high pumping intensity required to excite the multi-excitonic states. Here, we have addressed these issues by integrating monodisperse QDs in multi-excitonic states into a specially designed cavity, in which the QDs exhibit an anisotropic polychromatic emission (APE) characteristic that allows for tuning the emission from green to red by shifting the observation direction from perpendicular to lateral.
View Article and Find Full Text PDFSoft Matter
January 2025
Division of Physical Chemistry, Department of Chemistry, Lund University, PO Box 124, SE-221 00 Lund, Sweden.
Attempts to use colloid science concepts to better understand the dynamic properties of concentrated or crowded protein solutions are challenging due to the fact that globular proteins generally have heterogeneous surfaces that result in anisotropic or patchy contributions to their interaction potential. This is particularly difficult when targeting non-equilibrium transitions such as glass and gel formation in concentrated protein solutions. Here we report a systematic study of the reduced zero shear viscosity of the globular protein -crystallin, an eye lens protein that plays a vital role in vision-related phenomena such as cataract formation or presbyopia, and compare the results to the existing structural and dynamic data.
View Article and Find Full Text PDFSmall
January 2025
DWI-Leibniz Institute for Interactive Materials e.V., RWTH Aachen University, Forckenbeckstr. 50, 52074, Aachen, Germany.
Compartmentalization is crucial for control over complex biological cascade reactions. In microgels, the formation of discrete compartments allows for simultaneous uptake and orthogonal release of physicochemically distinct drugs, among others. However, many state-of-the-art approaches yielding compartmentalized microgels require the use of specific, though not always biocompatible, components and temperatures well above the physiological range, which may damage possible biological cargo.
View Article and Find Full Text PDFACS Nano
January 2025
Jiangsu Key Laboratory of Frontier Material Physics and Devices, School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006, China.
Circular differential scattering (CDS) spectroscopy has been developed as a powerful method for the characterization of the optical activity of individual plasmonic nanostructures and their complexes with chiral molecules. However, standard measurement setups often result in artifacts that have long raised concerns on the interpretation of spectral data. In fact, the detection limit of CDS setups is constrained by the high level of artifacts, to ±10%.
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