Langmuir and Langmuir Blodgett films of zinc oxide (ZnO) nanocrystals coated with polyhedral oligomeric silsesquioxanes (POSS)

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:600

Article

Paczesny, Jan¹  Wolska-Pietkiewicz, Malgorzata²  Binkiewicz, Ilona^1,2  Janczuk-Richter, Marta¹ 

[1] Inst Phys Chem PAS, Kasprzaka 44-52, PL-01224 Warsaw, Poland

[2] Warsaw Univ Technol, Fac Chem, Noakowskiego 3, PL-00664 Warsaw, Poland

关键词: ZnO;    POSS;    Langmuir-Blodgett films;    Self-assembly;    Interdigitation;    Ligands;    Hybrid nanomaterials;    Thin films;   

DOI  :  10.1016/j.jcis.2021.05.085

来源: Elsevier

【 摘 要 】

Hypothesis: The type and properties of ligands capping nanoparticles affect the characteristics of corre-sponding Langmuir and Langmuir-Blodgett films. When ligands are firmly anchored to the surface, as in zinc oxide nanocrystallites (ZnO NCs), compression at the air/water interface might cause ligands interdigitation and then the formation of supra-structures. Here, we evaluate how the introduction of bulky ligands, namely polyhedral oligomeric silsesquioxanes (POSSs), influences the self-assembly of POSS@ZnO NCs and the properties of corresponding thin films. Experiments: ZnO NCs capped with asymmetrical POSS derivatives are prepared via a one-pot two-step self-supporting organometallic (OSSOM) method. POSS@ZnO NCs are characterized by employing STEM, DLS, TGA, NMR, IR, UV-VIS, and photoluminescence spectroscopy. Changes in surface pressure, surface potential, and morphology (using BAM) are recorded upon compression at the air/water interface. Films transferred onto solid substrates are examined utilizing XRR and AFM. Findings: All studied POSS@ZnO NCs form stable Langmuir films. POSSs prevent the interdigitation of ligands capping neighboring NCs. Thus, POSS@ZnO NCs films resemble those composed of classical amphiphiles but without any visible structural source of amphiphilicity. We suggest that the core pro-vides enough hydrophilicity to anchor NCs at the air/water interface. POSS ligands provide enough hydrophobicity for the NCs not to disperse into the subphase upon compression. (c) 2021 The Author(s). 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