The first recyclable polymer-supported electrophilic fluorinating agent was prepared by reaction of molecular fluorine with the triethylenediamine motif that is grafted onto a poly(4-vinylbenzyl chloride-co-divinylbenzene) polyHIPE material. The resulting polymeric SelectfluorTM-type reagent demonstrated high efficiency in the fluorination of naphthol in the course of repeated sequences of fluorination and regeneration. It also reacted with the enol form and the sodium enolate of 1,3-dicarbonyl compounds.
COBISS.SI-ID: 30090791
The fabrication of polyHIPE polymer (PHP) was specifically tailored to produce a highly porous (85%) structure with the primary pore size in the range of 50–170 µm for cartilage tissue engineering. The resulting PHP scaffold was proven biocompatible with human articular chondrocytes and viable cells were observed within the materials as evaluated using the Live/Dead assay and histological analysis. Chondrocytes with round nuclei were organized into multicellular layers on the PHP surface and were observed to grow approximately 300 µm into the scaffold interior.
COBISS.SI-ID: 19662102
The incorporation of magnetic barium hexaferrite nanoparticles in a transparent polymer matrix of poly(methyl methacrylate) (PMMA) is reported for the first time. The barium hexaferrite nanoplatelets doped with Sc3+, i.e., BaSc0.5Fe11.5O12 (BaHF), having diameters in the range 20 to 130 nm and thicknesses of approximately 5 nm, are synthesized hydrothermally and stabilized in 1-butanol with dodecylbenzenesulfonic acid. This method enables the preparation of monolithic nanocomposites by admixing the BaHF suspension into a liquid monomer, followed by insitu, bulk free-radical polymerization.
COBISS.SI-ID: 18777878
Reducing the surfactant amount below generally accepted values in polyHIPE chemistry allowed for distinctly improving the mechanical properties of ROMP derived HIPE templated poly(dicyclopentadiene) without compromising the open cellular structure of the scaffold rendering the preparation of a ductile polymer foam with 80% porosity and a Young's modulus of 110 MPa possible.
COBISS.SI-ID: 16512022
Modifications of Cu and Cu40Zn surfaces were achieved by their immersions in ethanol solutions of stearic acid with and without the additions of Vitamin E. The surface morphologies, wettability, and corrosion resistance were characterised by means of SEM, water contactangle, potentiodynamic measurements and EIS. The corrosive media was artificially prepared acid rain at 25 °C. Significant increase in the contact angle indicated that the biomimetic morphology effectively repelled water from the metal surface. Electrochemical measurements indicated that Vitamin E additionally improved the inhibitory properties of the asprepared hydrophobic layer against corrosion. The inhibitive effectiveness increased to more than 99%.
COBISS.SI-ID: 28503847
Membrane assisted crystallization (MACr) offers an innovative platform for crystallizing Na2CO3, allowing its reuse after CO2 capture from flue gases by an alkaline solution (i.e., NaOH). In this study, the biomimetic aquaporin Inside™ membrane AIM60 was employed to enhance water removal, facilitating Na2CO3 crystallization. The water channel in the active layer, comprising aquaporin proteins, and the strong wettability of membrane substrate assist a better performance. For instance, the water flux of AIM60 membrane for concentrating a 1.89 mol L-1 Na2CO3 solution (osmotic pressure of 94.8 bar) in forward osmosis (FO) mode was 6.62 L m-2 h-1 and 3.25 L m-2 h-1 in pressure retarded osmosis (PRO) mode when a 5.13 mol L-1 NaCl solution (osmotic pressure of 304.9 bar) was employed as the draw solution. This demonstrates that the AIM60 FO membrane outperformed the previously reported dense reverse osmosis membrane (0.21 L m-2 h-1 in FO mode and 0.16 L m-2 h-1 in PRO mode) and a porous hydrophobic hollow fiber membrane (0.08 L m-2 h -1) under the same operating conditions. Crystallization utilizing the AIM60 membrane in an osmotic crystallizer was achieved without noticeable membrane scaling or degradation. Furthermore, a proper control of the supersaturation level induces crystallization of Na2CO3·10H2O crystals with a purity of 99.94%. Hence, the aquaporin Inside™ FO membrane may be a promising alternative to existing methods for Na2CO3 crystallization for its application in a CO2 capture scenario.
COBISS.SI-ID: 19193878
The influence of heat treatment on AISI 420 in 0.1 M H2SO4 was studied at passive potentials and increasing temperatures of acid, which lowers the passivity process and accelerates the dissolution of protective layers. Samples were compared with potentiodynamic measurements, EIS, SEM and EDS analysis. From Ea, ?‡H° and?‡S°, further corrosive behaviour can be predicted in terms of the activation energy needed for the initiation of a chemical process on a metal surface: whether either passivation or dissolution of protective layer is preferred. In respect of those values, the passivity efficiency factor ?pass was introduced and represents best corrosion behaviour as it exceeds value 1.
COBISS.SI-ID: 19114262
Conventional treatment of wastewater from the metal finishing industry is generally based on physical-chemical treatment. Although the effluents from this can be discharged directly there is an increasing interest in industrial wastewater reuse. This requires further wastewater treatment. Here we studied the technical and economic feasibilities of adding an ultrafiltration process as a pre-treatment for removing dissolved and colloidal contaminants ) 0.4 nm, and to eliminate membrane fouling before a final reverse osmosis process resulting in permeate that would meet reuse criteria. The results show that the ultrafiltration - reverse osmosis treatment removed between 91.3% and 99.8% of the contaminants from the effluent, such as metal elements, organic, and inorganic compounds. Contaminants such as suspended solids, nickel, ammonium nitrogen, sulphate nitrogen, chemical oxygen demand, and biochemical oxygen demand were completely removed, the concentrations in the permeate being under the detection limits, thus the quality of the ultrafiltration - reverse osmosis process met the reuse criteria. This demonstrates the technological feasibility of wastewater reuse during electro-plating processes and the pre-treatment of powder coating processes. An economic feasibility analysis was performed based on a reuse capacity for 30,000 m3 per year of treated water for two selected production lines at the Gorenje facility at Velenje, Slovenia. Specifically, the current water costs (including the operational costs of wastewater treatment, potable water use for industrial process and pre-treatment, and taxes) were compared with the investment required to implement the ultrafiltration - reverse osmosis processes. Based on the presented scientific results, the analysis shows that there is a potential for implementing this process within the metal finishing industry.
COBISS.SI-ID: 18622998
In this study, we investigated facile sonochemical synthesis, combined with the calcination process for the preparations of TiO2-MWCNT composites with different mole ratios of titanium and carbon. In order to produce stable nano dispersions we exploited an innovative biotechnology-based approach for the covalent functionalizations of TiO2-MWCNTs with in-situ synthesized soluble phenoxazine dye molecules.
COBISS.SI-ID: 19155734
Macroporous polymer composites with included alumina particles were prepared via an emulsion templating procedure by photopolymerising the monomer containing continuous phase. Methylmethacrylate and multifunctional acrylate monomer Sartomer SR 492 were used for the polymer matrix. Composites with open porous cellular morphology with cavities around 15 micron were obtained and further processed by a calcination and sintering process to form alumina ceramic material with the same morphology as the polymer composite precursors.
COBISS.SI-ID: 19206422