1. Molybdate and vanadate ions as corrosion inhibitors for clad aluminium alloy 2024-T3Ingrid Milošev, Tjaša Pavlovčič, Matija Tomšič, 2024, izvirni znanstveni članek Povzetek: Molybdate and vanadate ions were used as corrosion inhibitors for the clad aluminium alloy 2024-T3 in chloride solution to investigate the differences in their inhibitory effect. Electrochemical measurements in 0.1 M NaCl investigated the influence of inhibitor concentration from 0.5 mM to 250 mM, solution pH from 5 to 9 and immersion time at open circuit potential of up to 12 h. Both compounds act predominantly as anodic inhibitors; however, the effect of molybdate increases significantly at concentrations above 50 mM and leads to a broad passive range. Surface analysis of the samples exposed to inhibitor performed by X-ray photoelectron spectroscopy showed that the inhibitor layers consist of oxides of multiple valences. Scanning electron microscopy with chemical analysis was also used to characterise the inhibitor layers. Equilibrium diagrams of the aqueous species in the selected concentration range were generated to better understand the inhibition mechanism and to correlate the electrochemical data and data on surface properties.
Ključne besede: molybdate, corrosion inhibitors, aqueous chemistry
Objavljeno v DiRROS: 18.04.2025; Ogledov: 2258; Prenosov: 739
 Celotno besedilo (14,88 MB)
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2. Succinylation of polyallylamine: influence on biological efficacy and the formation of electrospun fibersLucija Jurko, Matej Bračič, Silvo Hribernik, Damjan Makuc, Janez Plavec, Filip Jerenec, Sonja Žabkar, Nenad Gubeljak, Alja Štern, Rupert Kargl, 2021, izvirni znanstveni članek Povzetek: Succinylation of proteins is a commonly encountered reaction in biology and introduces negatively charged carboxylates on previously basic primary amine groups of amino acid residues. In analogy, this work investigates the succinylation of primary amines of the synthetic polyelectrolyte polyallylamine (PAA). It investigates the influence of the degree of succinylation on the cytotoxicity and antibacterial activity of the resulting polymers. Succinylation was performed in water with varying amounts of succinic anhydride and at different pH values. The PAA derivatives were analyzed in detail with respect to molecular structure using nuclear magnetic resonance and infrared absorbance spectroscopy. Polyelectrolyte and potentiometric charge titrations were used to elucidate charge ratios between primary amines and carboxylates in the polymers. The obtained materials were then evaluated with respect to their minimum inhibitory concentration against Staphylococcus aureus and Pseudomonas aeruginosa. The biocompatibility was assessed using mouse L929 fibroblasts. The degree of succinylation decreased cytotoxicity but more significantly reduced antibacterial efficacy, demonstrating the sensitivity of the fibroblast cells against this type of ampholytic polyelectrolytes. The obtained polymers were finally electrospun into microfiber webs in combination with neutral water-soluble polyvinyl alcohol. The resulting non-woven could have the potential to be used as wound dressing materials or coatings.
Ključne besede: polyallylamine hydrochloride, succinylation, aqueous chemistry, cytotoxicity, antimicrobial effect, electrospinning, nanofibers, mouse L929 fibroblasts, Staphylococcus aureus, Pseudomonas aeruginosa
Objavljeno v DiRROS: 19.07.2024; Ogledov: 1397; Prenosov: 1275
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