Several acrylic hydrogels were prepared via ultrasonic polymerization of water soluble monomers and macromonomers. Ultrasound was used to create initiating radicals in viscous aqueous monomer solutions using the additives glycerol, sorbitol or glucose in an open system at 37 degrees C. The water soluble additives were essential for the hydrogel production, glycerol being the most effective. Hydrogels were prepared from the monomers 2-hydroxyethyl methacrylate, poly(ethylene glycol) dimethacrylate, dextran methacrylate, acrylic acid/ethylene glycol dimethacrylate and acrylamide/bis-acrylamide. For example a 5% w/w solution of dextran methacrylate formed a hydrogel in 6.5min in a 70% w/w solution of glycerol in water at 37 degrees C with 20kHz ultrasound, 56Wcm(-2). The ultrasonic polymerization method described here has a wide range of applications such a biomaterial synthesis where initiators are not desired.
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http://dx.doi.org/10.1016/j.ultsonch.2009.08.008 | DOI Listing |
Polymers (Basel)
December 2024
E.T.S. de Ingeniería y Diseño Industrial, Universidad Politécnica de Madrid (España), 28040 Madrid, Spain.
Polymers are often insulators, but this not a universal intrinsic characteristic of all polymers. For this work, the adhesives used, epoxy and polyurethane, do demonstrate this insulating characteristic. However, there has been significant interest in the development of conductive polymers, specifically adhesives, because of the potential properties and ease of processing of these polymers.
View Article and Find Full Text PDFJ Craniofac Surg
January 2025
Department of Biomedical Engineering, University of Illinois, Chicago, IL.
Bioabsorbable internal fixation is a well-accepted modality that is especially suitable for application in craniosynostosis. When first introduced, high rates of adverse tissue reactions were observed that have since been ameliorated with more biocompatible polymer formulations. However, the phenomenon has not entirely disappeared, and such reactions remain vexing.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Mechanical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
Advanced energetic composites possess promising properties and wide-ranging applications in explosives and propellants. Nonetheless, most metal-based energetic composites present significant challenges due to surface oxidation and low-pressure output. This study introduces a facile method to develop energetic composites Cutztr@AP through the intermolecular assembly of nitrogen-rich energetic coordination polymers and high-energy oxidant ammonium perchlorate (AP).
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Département de Génie Électrique, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montreal, QC H3C 1K3, Canada.
This study explored the influence of graphene oxide (GO) on morphological and mechanical properties of Nafion 115 membranes with the objective of enhancing the mechanical properties of the most widely employed membrane in Proton Exchange Membrane Water Electrolyzers (PEMWE) applications. The membrane surface was modified by ultrasonically spraying a GO solution and different annealing temperatures were tested. Scanning Electron Microscopy (SEM) cross-sectional images revealed that annealing the composite membranes was sufficient to favor an interaction between the graphene oxide and the surface of the Nafion membranes.
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.
Purpose: The purpose of this study was to characterize whether pulsed ultrasound (PUS) affects transscleral drug delivery.
Methods: Fluorescein sodium (NaF, 376 Da) and fluorescein isothiocyanate-conjugated dextran 40 (FD-40, 40 kDa) were used as model drugs. Human sclera grafts were placed in modified Franz diffusion cells and were treated by PUS (1 megahertz [MHz], 0.
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