Crack Reduction during Drying Process by Using Surfactant

In this research clay brick samples were made from illitic clays. Surfactant was added to clay mass during formation process to reduce crack generation during drying process. Surfactant amount was changed below critical micelle concentration (CMC). Nonionic surfactant Triton X-100 was used. Samples were prepared using extruder. Clay mass samples were analysed by granulometry, surfactant by contact angle and surface tension measurements and brick samples by microscope to determine crack amount. Changing surfactant amount closer to CMC is possible to reduce crack amount in sample during drying stage

Identifying iron-bearing nanoparticle precursor for thermal transformation into the highly active hematite photo-fenton catalyst

Funding: This reseach was funded by the European Regional Development Fund within the Activity 1.1.1.2 “Post-doctoral Research Aid” of the Specific Aid Objective 1.1.1 “To increase the research and innovative capacity of scientific institutions of Latvia and the ability to attract external financing, investing in human resources and infrastructure” of the Operational Programme “Growth and Employment” (No. 1.1.1.2/VIAA/1/16/157).The hematite photo-Fenton catalysis has attracted increasing attention because it offers strong oxidation of organic pollutants under visible light at neutral pH. In the present work, aqueous synthesis of hematite photo-Fenton catalysts with high activity is demonstrated. We compare photo-Fenton activity for hematite obtained by hydrolyzation at 60◦C or by a thermally induced transformation from iron-bearing nanoparticles, such as amorphous iron oxyhydroxide or goethite. A link between their structure and visible light photo-Fenton reactivity is established. The highest activity was observed for hematite obtained from goethite nanowires due to oblong platelet-like structure, high surface area and the presence of nanopores.European Regional Development Fund 1.1.1.2/VIAA/1/16/157; 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 CAMART

Exfoliated MoS2 Nanosheet/Cellulose Nanocrystal Flexible Composite Films as Electrodes for Zinc Batteries

The study presents a more efficient way of exfoliating MoS2 in water and the exfoliated MoS2 was used in an electrode. The electrodes were prepared from exfoliated MoS2 (active material)-nanocrystalline cellulose (binder) with carbon nanotubes (electron-conducting support) and demonstrated in a zinc battery half-cell that showed a Coulombic efficiency of 90%. Successful exfoliation of MoS2 was done by sonication of bulk MoS2 with sulfated cellulose nanocrystals (CNC) for 4 h. The exfoliation was confirmed by Raman and transmission electron microscopy; interestingly, the Raman signals for exfoliated MoS2 show a blue shift for both A1g and E2g1 bands, which may be an indication of an induced lattice strain effect from the CNC on MoS2. The resulting stable water suspension showed no tendency of precipitation after 2 months of standing. The zeta potential, ζ, for sodium sulfated CNC (CNC-OSO3Na)-MoS2 in water suspension was −45 mV, whereas sulfated CNC (CNC-OSO3H)-MoS2 in water suspension had a zeta potential of −35 mV. The sodium form of sulfated CNCs displayed micelle characteristics, similar to sodium dodecyl sulfate (SDS), with a critical aggregation concentration (CAC) of 1.1 wt %. At CAC, the CNCs efficiently exfoliated MoS2, which is at a much lower concentration than has been reported for synthetic surfactants like SDS and cetyl trimethyl ammonium bromide

Bifurcated Asymmetric Field Flow Fractionation of Nanoparticles in PDMS-Free Microfluidic Devices for Applications in Label-Free Extracellular Vesicle Separation

Extracellular vesicles are small membrane-bound structures that are released by cells and play important roles in intercellular communication garnering significant attention in scientific society recently due to their potential as diagnostic and therapeutic tools. However, separating EVs from large-volume samples remains a challenge due to their small size and low concentration. In this manuscript, we presented a novel method for separating polystyrene beads as control and extracellular vesicles from large sample volumes using bifurcated asymmetric field flow fractionation in PDMS-free microfluidic devices. Separation characteristics were evaluated using the control system of polystyrene bead mix, which offers up to 3.7X enrichment of EV-sized beads. Furthermore, in the EV-sample from bioreactor culture media, we observed a notable population distribution shift of extracellular vesicles. Herein presented novel PDMS-free microfluidic device fabrication protocol resulted in devices with reduced EV-loss compared to size-exclusion columns. This method represented an improvement over the current state of the art in terms of EV separation from large sample volumes through the use of novel field flow fractionation design

Bifurcated Asymmetric Field Flow Fractionation of Nanoparticles in PDMS-Free Microfluidic Devices for Applications in Label-Free Extracellular Vesicle Separation

Extracellular vesicles are small membrane-bound structures that are released by cells and play important roles in intercellular communication garnering significant attention in scientific society recently due to their potential as diagnostic and therapeutic tools. However, separating EVs from large-volume samples remains a challenge due to their small size and low concentration. In this manuscript, we presented a novel method for separating polystyrene beads as control and extracellular vesicles from large sample volumes using bifurcated asymmetric field flow fractionation in PDMS-free microfluidic devices. Separation characteristics were evaluated using the control system of polystyrene bead mix, which offers up to 3.7X enrichment of EV-sized beads. Furthermore, in the EV-sample from bioreactor culture media, we observed a notable population distribution shift of extracellular vesicles. Herein presented novel PDMS-free microfluidic device fabrication protocol resulted in devices with reduced EV-loss compared to size-exclusion columns. This method represented an improvement over the current state of the art in terms of EV separation from large sample volumes through the use of novel field flow fractionation design