Browsing by Subject "hydrophilicity"

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Access status: Open Access ,
Jak termodynamika i mechanika opisują makroskopową oraz molekularną istotę zwilżalności
(2007) Grodzka, Janina; Pomianowski, Andrzej Aleksander
Recent studies on wetting lead to the two most important conclusions: description (estimation) of wettability needs the knowledge of not only the macroscopic wetting angle but also of the nature of molecular aqueous films that occupy surfaces of all solids; mechanical equilibrium of the wetting process is generally much more rapidly established than the thermodynamic equilibrium of the whole system. In consequence, the macroscopically measured wetting angle is different from the equilibrium angle, when the thermodynamic equilibrium and the formation of the molecular water film on the solid are not attained. Rapidly proceeding investigations of molecular wettability, carried out with the use of AFM (atomic force microscopy), will lead in the near future to unification of the theory and practice of wetting, and in particular will solve the question of the hysteresis of wetting, resulting from changes in the structure of water, directly adjacent to the surfaces of solids.
Access status: Open Access ,
Strength, water absorption, thermal and antimicrobial properties of a biopolymer composite wound dressing
(AGH University of Science and Technology Press, 2022) Chiosa Odili, Cletus; Sekunowo, Olatunde Israel; Ilomuanya, Margaret Okonawan; Gbenebor, Oluwashina Philips; Adeosun, Samson Oluropo
Conventional wound material allows bacterial invasions, trauma and discomfort associated with the changing of the dressing material, and the accumulation of body fluid for wounds with high exudate. However, there is a shift from conventional wound dressing materials to polymeric nanofibers due to their high surface area to volume ratio, high porosity, good pore size distribution, which allows for cell adhesion and proliferation. There is an urgent need to synthesis a biodegradable composite that is resistant to bacterial infection. In this study, an electrospun polylactide (PLA) composite suitable for wound dressing, with enhanced antimicrobial and mechanical properties, was produced. The neat PLA, PLA/CH (10 wt.%), PLA/CH (5 wt.%), PLA/CHS (10 wt.%), PLA/CHS (5 wt.%), PLA/CH (2.5 wt.%) /CHS (2.5 wt.%) and PLA/CH (5 wt.%)/CHS (5 wt.%), were electrospun using 0.14 g/ml solution. Results show that crystallinity (67.6%) of neat PLA declined by 3.8% on the addition of 2.5 wt.% chitin/chitosan with improved hydrophilicity of the composite. The tensile strength of neat PLA (0.3 MPa) increased (0.6 MPa) with 2.5 wt.% chitin/chitosan addition. The slight increase in the glass transition temperature from 75°C for neat PLA to 78°C of the composite fibre, showed improved ductility. The fibres showed little beads, hence suitable for wound dressing. The electrospun mats have good water absorption capacity and strong resistance against <i>Staphylococcus aureus</i>. Good performance was attained at 5 wt.% of chitin, chitosan and hybrid reinforcements. Therefore, a PLA/chitin/chitosan composite is recommended as a wound dressing material.