The present theoretical study deals with microparticles (beads) that contain an immobilized Belousov-Zhabotinsky (BZ) reaction catalyst. In the theoretical experiment, a BZ bead is immersed in a small water droplet that contains all of the BZ reaction reagents but no catalyst. Such heterogeneous reaction-diffusion BZ systems with the same BZ reactant concentrations demonstrate various dynamic modes, including steady state and low-amplitude, high-amplitude, and mixed-mode oscillations (MMOs). The emergence of such dynamics depends on the sizes of the bead and water droplet, as well as on the location of the bead inside the droplet. MMO emergence is explained by time-delayed positive feedback in combination with a canard phenomenon. If two identical BZ beads are immersed in the same droplet, many different dynamic modes including chaos are observed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1063/1.5126404 | DOI Listing |
Pharmaceutics
December 2024
AbbVie Deutschland GmbH & Co. KG, Knollstraße, 67061 Ludwigshafen am Rhein, Germany.
Atomization plays a key role in spray drying, a process widely used in the pharmaceutical, chemical, biological, and food and beverage industries. In the pharmaceutical industry, spray drying is particularly important in the preparation of amorphous solid dispersions, which enhance the bioavailability of active pharmaceutical ingredients when mixed with a polymer. In this study, a 3D-printed adaptation of a commercial spray dryer nozzle (PHARMA-SD PSD-1, GEA Group AG) was used to investigate the atomization of PVP-VA 64 polymer solutions under varying flow conditions using high-speed diffuse back-illumination.
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
Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology (KITECH), Cheonan 31056, Republic of Korea.
Recent advancements in polymer materials have enabled the synthesis of bio-based monomers from renewable resources, promoting sustainable alternatives to fossil-based materials. This study presents a novel zwitterionic surfactant, SF, derived from 10-undecenoic acid obtained from castor oil through a four-step reaction, achieving a yield of 78%. SF has a critical micelle concentration (CMC) of 1235 mg/L, slightly higher than the commercial anionic surfactant Rhodacal DS-4 (sodium dodecyl benzene sulfonate), and effectively stabilizes monomer droplets, leading to excellent conversion and stable latex formation.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan Campus, 170 Kessels Road, Brisbane, QLD 4111, Australia.
The evaporation dynamics of sessile droplets on re-entrant microstructures are critical for applications in microfluidics, thermal management, and self-cleaning surfaces. Re-entrant structures, such as mushroom-like shapes with overhanging features, trap air beneath droplets to enhance non-wettability. The present study examines the evaporation of a water droplet on silicon carbide (SiC) and silicon dioxide (SiO) re-entrant structures, focusing on the effects of material composition and solid area fraction on volume reduction, contact angle, and evaporation modes.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
Institute of Life Science and Resources & Department of Food Science and Biotechnology, College of Life Sciences, Kyung Hee University, Yongin 17104, Republic of Korea.
This study introduces a novel method for the fabrication of concave microwells involving water vapor permeation through polydimethylsiloxane (PDMS). This method leverages the exceptional water vapor permeability of PDMS to enable a scalable and cost-effective fabrication process, addressing the limitations of existing techniques such as photolithography that are resource-intensive and complex. PDMS is more permeable to water vapor than to other gas molecules, resulting in the formation of microwells.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!