Hypothesis: Contact angle can be a key parameter in chemical engineering. However, the development and the optimization of numerous processes using supercritical CO, considered as environmentally friendly, require new measurements under dense CO atmosphere. Besides, the influence of the roughness or the wetting regime on the contact angle is known at ambient conditions but remains to be discussed for systems under high pressure.
Experimental: Contact angle measurements of ethanol, water, and their mixtures, with ethanol mass fractions ranging from 0.25 to 0.75, on two stainless steels in saturated CO at pressures ranging from 0.1 MPa to 15.1 MPa, and at313 K and 333 K were carried out in a set-up improving mass transfer between the studied liquid and the continuous fluid phase. Stainless steel surfaces have been characterized by atomic force and scanning electron microscopies allowing the application of the Wenzel equation.
Findings: Ethanol wetted totally both stainless steels while contact angles of all other liquids were increased by the rise of pressure, with contact angles up to 128° for water at 15.1 MPa. Trapped bubbles were observed at the solid/liquid interface and the bubble formation is discussed. Furthermore, the potential influence of bubble presence on the wetting regime is prospected through the question: could the pressure rise modify the wetting regime?
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jcis.2023.10.163 | DOI Listing |
Int J Biol Macromol
January 2025
Department of Chemistry, State University of Maringá, Maringá, PR, Brazil; Laboratory of Materials, Macromolecules, and Composites, Federal University of Technology - Paraná, Apucarana, PR, Brazil; National Institute for Materials Advancement, Pittsburg State University, Pittsburg, KS, USA; Department of Chemistry, Pittsburg State University, Pittsburg, KS, USA. Electronic address:
Polyelectrolyte multilayers (PEMs) based on hyaluronic acid (HA) and poly (diallyldimethylammonium chloride) (PDDA) were deposited on oxidized polystyrene (PS) via the layer-by-layer (LbL) method. The X-ray photoelectron spectroscopy (XPS) confirmed the PEM deposition on PS, and atomic force microscopy (AFM) indicated that the surface roughness of PS also increased after PEM deposition. The PEMs significantly enhanced PS wettability, reducing the contact angle from 73° on PS to 24° on PDDA-terminated (PDDA/HA) PEM (2.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing 100193, China.
In this context, we reported for the first time the design and development of a self-assembled nanoantiviral pesticide based on the star polycation (SPc) and the broad-spectrum fungicide/antiviral agent seboctylamine for field control of (SMV), a highly destructive plant virus in soybean crops. The SPc could self-assemble with seboctylamine through hydrogen bonds and van der Waals forces, and the complexation with SPc reduced the particle size of seboctylamine to form a spherical seboctylamine/SPc complex. In addition, the contact angle of seboctylamine decreased, and its retention increased with the aid of SPc, indicating excellent wetting properties and strong leaf surface adhesion performance.
View Article and Find Full Text PDFLangmuir
January 2025
Materials Chemistry Centre, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K.
Durable and fluorine-free superhydrophobic films were fabricated by a simple two-step process involving the pretreatment of glass substrates with an epoxysilane, which acted as an adhesive. The next step involved the aerosol-assisted chemical vapor deposition of a simple mixture of polydimethylsiloxane (PDMS) and SiO nanoparticles (NPs). Various parameters were studied, such as deposition time as well as PDMS and SiO loadings.
View Article and Find Full Text PDFCurr Drug Deliv
January 2025
Department of Pharmaceutical Sciences, School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Background: Hot-melt Pressure-sensitive Adhesives (HMPSA) are eco-friendly pressuresensitive adhesives, with the potential of being used as substrates for transdermal patches. However, due to the low hydrophilicity of HMPSA, the application is limited in the field of Traditional Chinese Medicine (TCM) plasters.
Methods: Three modified HMPSA were prepared with acrylic resin EPO, acrylic resin RL100, and Polyvinylpyrrolidone (PVP) as the modifying materials.
ACS Appl Mater Interfaces
January 2025
School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, P. R. China.
Aerogels are regarded as the next generation of thermal insulators; however, conventional aerogels suffer from issues such as brittleness, low moisture resistance, and a complex production process. Subnanowires (SNWs) are emerging materials known for their exceptional flexibility, toughness, intrinsic hydrophobicity, and gelling capabilities, making them ideal building blocks for flexible, tough, hydrophobic, and thermally insulating aerogels. Herein, we present a simple and scalable strategy to construct SNW aerogels by freeze-drying hydroxyapatite (HAP) SNW dispersions in cyclohexane.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!