Cleaning represents an important and challenging operation in the conservation of cultural heritage, and at present, a key issue consists in the development of more sustainable, "green" materials and methods to perform it. In the present work, a novel xylene-in-water microemulsion based on nonionic surfactants with low toxicity was obtained, designed as low-impact cleaning agent for metallic historic objects. Phase diagram of the mixtures containing polyoxyethylene-polyoxypropilene triblock copolymer Pluronic P84 and D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) as surfactants, water, ethanol and xylene was studied, and a microemulsion with low surfactant content was selected as suitable cleaning nanosystem.
View Article and Find Full Text PDFThis study was focused on creating a new and effective immobilization method for Trametes versicolor laccase (Lc) by using chitosan (CS) microspheres activated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride. The activation of the support alternated with immobilization of the enzyme, in repetitive procedures, led to obtaining three different products. Also, the physicochemical properties of the new products were investigated and compared with those of free laccase.
View Article and Find Full Text PDFCarbohydr Polym
October 2020
The study sheds light on the interaction between chitosan (Ch) and polyglycidol (PGL) and uses their interpolymer complex in hydrophilic coating of iron oxide particles (M). Preliminary investigations were performed by modeling chitosan and polyglycidol chains interactions using coarse grained beads approximation and molecular dynamics simulations. The results revealed that Ch and PGL chains associate together forming weak strength complexes, which was experimentally confirmed by surface tension, fluorescence and FTIR.
View Article and Find Full Text PDFThe binding of drugs to serum proteins is governed by weak non-covalent forces. In this study, the nature and magnitude of the interactions between piroxicam (PRX) and bovine serum albumin (BSA) was assessed using spectroscopic, calorimetric and computational molecular methods. The fluorescence data revealed an atypical behavior during PRX and BSA interaction.
View Article and Find Full Text PDFJ Photochem Photobiol B
December 2015
The study systematically investigates aqueous mixtures of fixed bovine serum albumin (BSA) and various ethoxylated nonionic surfactants belonging to a homologous series or not. Mono-disperse tetra-(C12E4), hexa-(C12E6) and octa-ethyleneglycol mono-n-dodecyl ether (C12E8), and poly-disperse eicosa-ethyleneglycol mono-n-tetradecyl ether (C14EO20) are respectively employed. Fluorescence and circular dichroism measurements are performed at surfactant/protein molar ratios (rm)s lower and higher than one.
View Article and Find Full Text PDFThe aim of the present investigation was to develop and evaluate microemulsion-loaded hydrogels (MEHs) for the topical delivery of fluconazole (FZ). The solubility of FZ in oils, surfactants and cosurfactants was evaluated to identify the components of the microemulsion. The pseudo-ternary phase diagrams were constructed using the novel phase diagram by micro-plate dilution method.
View Article and Find Full Text PDFNine important 1,4-benzodiazepines and zolpidem were characterized by liquid chromatography-mass spectrometry using a multimode ionization source able to generate ions using both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), and a single quadrupole mass analyzer. An optimum chromatographic separation was applied for all target compounds in less than 8 minutes using a Zorbax Eclipse Plus column (100 × 4.6 mm, 3.
View Article and Find Full Text PDFAt present there is no metallic ink that enables formation of conductive patterns at room temperature by a single printing step. Printing conductive features by metallic nanoparticle-based inks must be followed by sintering while heating to elevated temperatures, thus preventing their utilization on most plastic substrates used in plastic electronics. In this report we present a new silver nanoparticle-based conductive ink, having a built-in sintering mechanism, which is triggered during drying of the printed pattern.
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