Suchergebnisse

Authors of this work acknowledge funding from European Union`s Horizon 2020 Research and Innovation Program project under grant agreement No 768789. ; In this study, synthesis of sulfonated poly(ether ether ketone) (SPEEK) was performed using sulfonation method with concentrated sulfuric acid. Polymer with three degrees of sulfonation was obtained: 0.87; 0.82 and 0.74. Composite membranes were synthesized with an activated carbon. Ultrasonication method was used in order to achieve homogeneity of distribution of the additive in polymer solution and then in polymer membranes. Membranes with various content of the additive were made: 0; 0.15; 0.3; 0.5; 0.6; 0.8; 1.0; 2.0 and 3.0 %. Swelling degree, water uptake, proton conductivity, isoelectric point, thermal properties and surface morphology of the membranes were analyzed. Proton conductivity was determined using impedance analysis with two electrode system and through-plane configuration. Two methods were used: differential and single membrane method. Differential method is proposed to have significant advantage as it reduces contact resistance, which otherwise is difficult to control and evaluate. Surface zeta potential of membrane surface was investigated, and membranes have shown variation of the potential. Isoelectric point was determined for the membranes with DS 0.82 and carbon content 0 % and 0.5 %, and it was found to be at pH 4. Water uptake and swelling degree of the membranes was studied, and active carbon content was found to not have major influence on those properties, but higher content of sulfonic groups leads to increased water uptake and swelling degree. Thermogravimetric analysis showed slightly better thermal properties of membranes with the additive, compared to the blank membranes, which can be related to differences in the water uptake. Surface of the membrane was investigated using scanning electron microscopy, and no considerable defects were observed. ; Horizon 2020 No 768789; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

Ion conductivity of sulfonated poly (ether ether ketone) (SPEEK) membranes with various degree of sulfonation (DS) was investigated using impedance analysis with different measuring cell configuration and ion conductivity was calculated from resistances of polymer membranes. SPEEK was synthesized from poly (ether ether ketone) (PEEK) via sulfonation reaction in concentrated sulfuric acid (95-98%). Scanning electron microscopy (SEM) analysis of membrane surface was performed to determine possible mechanical damage to the membrane during resistance measurements. ; Horizon 2020 Research and Innovation Program project No 768789; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

Authors acknowledge support from LSC project No 2014/666 ERDF and students ( ) support from project 2DP/2.1.1.1.0/14/APIA/VIAA/009. ; SPEEK (sulfonated polyether ether ketone) membranes have been prepared and characterized. The SPEEK membrane geometry and theoretical vibration spectra calculated using density functional theory (DFT) as depending from membrane chain length and polymer cross-linking. Analyzed the limitations of the method by comparing theoretical and experimental IR spectra. ; LSC project No 2014/666 ERDF and project 2DP/2.1.1.1.0/14/APIA/VIAA/009; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

This work was supported by Latvian Council of Science (Cooperation project No.666/2014.4). ; Ionic liquid/sulphonated poly(ether ether ketone) composite membranes were prepared using following ionic liquids: 1,2,3-trimethylimidazolium dimethylphosphate, 1-hexyl-3-methylimidazolium dimethylphosphate, 1-dodecyl-3-methylimidazolium dimethylphosphate. For each ionic liquid/polymer pair 4 composite membranes were prepared with 10 wt.%, 20 wt.%, 30 wt.%, 40 wt.% ionic liquid content. Membranes were analyzed using strain-stress testing at various elevated temperatures up to 150 °C. Impact of temperature, ionic liquid content in membrane and structure of ionic liquids on mechanical properties of composite membrane were evaluated. It was found that temperature and ionic liquid content had highest impact on mechanical properties of composite membranes. ; Latvian Council of Science No.666/2014.4; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

A unique in vivo electrical pulse generator to improve membrane permeability for drugs and simultaneously facilitate self-powered nano devices for nano drug delivery systems (NDDS) was identified. The use of an unsupported biological catalyst component of the power supply was aimed at the NDDS instead of a conventional membrane electrode assembly (MEA). Self-powered carriers of drugs and prodrugs with improved controlled release capability to target areas using substrate available in biological matrices such as glucose in blood is envisaged. The experimental application implemented prototype designed chambers allowing the entry of premixed precursors and low ohm resistance due the absence of diffusion layers and optimised open circuit voltage (OCV). This would also minimise poisoning and rupturing of the proton exchange membrane (PEM). The model uses the isothermal experimental design (37°C) parameter and the glucose is partly oxidised prior to entry and mostly oxidised at the surface of the proton exchange membrane (PEM). The experimental model used a residence time instead of the usual flow rate. The power was notably high for short periods due to the absence of carbon supported diffusion layers. The findings included low levels of glucose and glucose oxidase (GOx) are needed for OCV optimisation. ; We wish to acknowledge the financial assistance of the National Research Foundation (NRF) and the Stellenbosch University support staff; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union's Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²