We employ a direct method, time-of-flight secondary ion mass spectroscopy (ToF-SIMS), to determine experimentally the chemical compositions of the wetted and dewetted regions of an uncured epoxy thin film. Determining the composition of the dewetted region indicated the presence of a very thin sublayer of resin in what was thought to be a region devoid of resin. The capability of ToF-SIMS to probe small 65 x 65 microm(2) areas of the surface has permitted us to directly compare the SIMS spectra of the wetted and dewetted regions to the survey spectra of the reactants. This may indicate the strength of resin/silica interactions, which determine interface formation and properties.
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http://dx.doi.org/10.1006/jcis.2002.8254 | DOI Listing |
J Am Chem Soc
December 2024
New Cornerstone Science Laboratory, Department of Chemistry, Institute of Biomimetic Materials and Chemistry, Anhui Engineering Laboratory of Biomimetic Materials, Division of Nanomaterials and Chemistry, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China.
Plateau-Rayleigh instability─a macroscopic phenomenon describing the volume-constant breakup of one-dimensional continuous fluids─has now been widely observed in adatoms, liquids, polymers, and liquid metals. This instability enables controlled wetting-dewetting behavior at fluid-solid interfaces and, thereby, the self-limited patterning into ordered structures. However, it has yet to be observed in conventional inorganic solids, as the rigid lattices restrict their "fluidity".
View Article and Find Full Text PDFNanotechnology
November 2024
Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México C.P. 04510, Mexico.
This study investigates the fluence-dependent evolution of gold nanoparticles formed through single nanosecond pulsed laser dewetting of a gold thin film on a fused silica substrate. By employing a well-defined Airy-like laser spatial profile and reconstructing scanning electron microscope images across the irradiation spot into a panoramic view, we achieve a detailed continuous analysis of the nanoparticle formation process. Our morphological analysis, combined with finite element thermal simulations directly correlated with the applied fluence, identifies two distinct thresholds.
View Article and Find Full Text PDFLangmuir
December 2024
Siemens Industry Software Netherlands B.V, The Hague 2595 BN, Netherlands.
This work provides a framework to digitally assess any droplet's static and dynamic contact angles on coatings and polymeric substrates. We are introducing a new dissipative particle dynamics coarse-grained model to attain the spatiotemporal conditions and the coexistence of different phases that such investigation dictates. Two computational techniques are additionally developed; a robust technique to calculate the static contact angle using density profiles and a perturbation method to evaluate dynamic contact angles.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, Massachusetts 02139, United States.
Fluid instabilities can be harnessed for facile self-assembly of patterned structures on the nano- and microscale. Evaporative self-assembly from drops is one simple technique that enables a range of patterning behaviors due to the multitude of fluid instabilities that arise due to the simultaneous existence of temperature and solutal gradients. However, the method suffers from limited controllability over patterns that can arise and their morphology.
View Article and Find Full Text PDFSmall
December 2024
Technical University of Munich, TUM School of Natural Sciences, Department of Physics, Chair for Functional Materials, James-Franck-Str. 1, 85748, Garching, Germany.
Morphology templates of solution-based diblock copolymer (DBC) films with loading metal salts are widely applied in photocatalysts, photovoltaics, and sensors due to their adjustable characteristics based on surface (de-)wetting and microphase separation. The present work investigates the morphologies of drop-cast hybrid films based on poly(styrene)-b-poly(ethylene oxide) (PS-b-PEO) and the metal salts titanium isopropoxide (TTIP) and zinc acetate dehydrate (ZAD) in comparison to the pure DBC. By utilizing scanning electron microscopy, grazing-incidence small- and wide-angle X-ray scattering, and differential scanning calorimetry, we find that the resulting film morphologies depend not only on the presence of metal salts but also on solvent evaporation and crystalline formation.
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