Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of spin-coated polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) films (<20nm thick) were mainly investigated by atomic force microscopy. Surface chemical analysis of the ultrathin films annealed for different times were performed using X-ray photoelectron spectroscopy and contact angle measurement. With the annealing of acetone vapor, dewetting of the films with different thicknesses occur via the spinodal dewetting and the nucleation and growth mechanisms, respectively. The PS-b-PMMA films rupture into droplets which first coalesce into large ones to reduce the surface free energy. Then the large droplets rupture into small ones to increase the contact area between PMMA blocks and acetone molecules resulting from ultimate migration of PMMA blocks to droplet surface, which is a novel dewetting process observed in spin-coated films for the first time.
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http://dx.doi.org/10.1016/j.jcis.2016.06.017 | DOI Listing |
Int J Nanomedicine
January 2025
Department of pharmacy, west china hospital, Sichuan University, Chengdu, 610041, People's Republic of China.
Amphiphilic copolymers are composed of both hydrophilic and hydrophobic chains, which can self-assemble into polymeric micelles in aqueous solution via the hydrophilic/hydrophobic interactions. Due to their unique properties, polymeric micelles have been widely used as drug carriers. Poorly soluble drugs can be covalently attached to polymer chains or non-covalently incorporated in the micelles, with improved pharmacokinetic profiles and enhanced efficacy.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.
ConspectusStructural DNA nanotechnology offers a unique self-assembly toolbox to construct soft materials of arbitrary complexity, through bottom-up approaches including DNA origami, brick, wireframe, and tile-based assemblies. This toolbox can be expanded by incorporating interactions orthogonal to DNA base-pairing such as metal coordination, small molecule hydrogen bonding, π-stacking, fluorophilic interactions, or the hydrophobic effect. These interactions allow for hierarchical and long-range organization in DNA supramolecular assemblies through a DNA-minimal approach: the use of fewer unique DNA sequences to make complex structures.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul 34956, Turkey.
Cold isostatic pressing, gel casting, and protein coagulation are the most common techniques to produce green bodies prior to computer numerical control (CNC)-based machining for the near-net-scale shaping of ceramics. These methods typically involve various additives and entail several steps to create a green body that is capable of withstanding machining forces. Here, utilizing a single additive, we first introduced a facile benchtop method to generate self-standing, malleable doughs of alumina in under 2 min.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Center of Excellence for Research in Engineering Materials (CEREM), Deanship of Scientific Research (DSR), King Saud University, Riyadh 11421, Saudi Arabia.
This study introduces a novel method to enhance the antibacterial functionality of electrospun nanofibrous textiles by integrating silver nanoparticles (AgNPs) into poly (lactic acid) (PLA) fabrics through pre- and post-electrospinning techniques. AgNPs were incorporated into hydrophobic and modified hydrophilic PLA textiles via pre-solution blending and post-solution casting. A PEG-PPG-PEG tri-block copolymer was utilized to enhance hydrophilicity and water stability, while AgNPs served as antibacterial agents.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemistry, University of Hannam, Daejeon 34430, Republic of Korea.
The chemical mechanical polishing/planarization (CMP) is essential for achieving the desired surface quality and planarity required for subsequent layers and processing steps. However, the aggregation of slurry particles caused by abrasive materials can lead to scratches, defects, increased surface roughness, degradation the quality and durability of the finished surface after milling processes during the CMP process. In this study, ceria slurry was prepared using polymer dispersant with zinc salt of ethylene acrylic acid (EAA) copolymer at different contents of 5, 6, and 7 wt% (denoted as D5, D6, and D7) to minimize particle aggregation commonly observed in CMP slurries.
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