A humido-responsive free-standing film has been created using layer-by-layer assembly technique. Polyethylenimine (PEI) at high pH was assembled with poly(acrylic acid) (PAA) at low pH on a Teflon substrate to yield a micro-nanostructured surface that can be made superhydrophobic after being coated with a low surface energy compound. The resulting asymmetric free-standing film with one surface being superhydrophobic while the other is hydrophilic after detachment from the substrate can undergo reversible bending/unbending shape transitions when the environmental humidity is changed. The bending/unbending movement of the free-standing film can be ascribed to the different responses of these two surfaces to humidity.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/la102928g | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Underwater superoleophobic and transparent (UST) films are promising in applications, such as advanced optical devices in marine environments. However, the mechanical robustness and durability in harsh environments of the existing UST films are still unsatisfactory. In this work, we present a free-standing nacre-inspired mineralized UST (NIM-UST) film with high aragonite content and excellent mechanical properties toward robust underwater superoleophobicity on two surfaces and transparency (94%) in harsh seawater environments.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Physics, Washington State University, Pullman, WA 99163, USA.
This work aims to determine the mechanism of the photomechanical response of poly(Methyl methacrylate) polymer doped with the photo-isomerizable dye Disperse Red 1 using the non-isomerizable dye Disperse Orange 11 as a control to isolate photoisomerization. Samples are free-standing thin films with thickness that is small compared with the optical skin depth to assure uniform illumination and photomechanical response throughout their volume, which differentiates these studies from most others. Polarization-dependent measurements of the photomechanical stress response are used to deconvolute the contributions of angular hole burning, molecular reorientation and photothermal heating.
View Article and Find Full Text PDFNat Nanotechnol
January 2025
Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China.
The miniaturization of light-emitting diodes (LEDs) is pivotal in ultrahigh-resolution displays. Metal-halide perovskites promise efficient light emission, long-range carrier transport and scalable manufacturing for bright microscale LED (micro-LED) displays. However, thin-film perovskites with inhomogeneous spatial distribution of light emission and unstable surface under lithography are incompatible with the micro-LED devices.
View Article and Find Full Text PDFMolecules
December 2024
College of Mechanical and Electronic Engineering, Tarim University, Alar 843300, China.
Angew Chem Int Ed Engl
December 2024
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai, 201418, China.
Laminating a free-standing carbon electrode film onto perovskite film is a promising method for fabricating HTM (hole transport material)-free carbon electrode perovskite solar cells (c-PSCs), offering more flexibility by decoupling the processes of carbon electrode and perovskite layer formation. However, the power conversion efficiency (PCE) of laminated HTM-free c-PSCs (<16.5 %) remains lower compared to c-PSCs with printed carbon pastes (>20 %), primarily due to poor interfacial contact between the perovskite and carbon layers.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!