| 1. |
- Tagaya, M., et al.
(författare)
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Reusable hydroxyapatite nanocrystal sensors for protein adsorption
- 2010
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 11:4
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Konferensbidrag (refereegranskat)abstract
- The repeatability of the adsorption and removal of fibrinogen and fetal bovine serum on hydroxyapatite (HAp) nanocrystal sensors was investigated by Fourier transform infrared (FTIR) spectroscopy and quartz crystal microbalance with dissipation (QCM-D) monitoring technique. The HAp nanocrystals were coated on a gold-coated quartz sensor by electrophoretic deposition. Proteins adsorbed on the HAp sensors were removed by (i) ammonia/hydrogen peroxide mixture (APM), (ii) ultraviolet light (UV), (iii) UV/APM, (iv) APM/UV and (v) sodium dodecyl sulfate (SDS) treatments. FTIR spectra of the reused surfaces revealed that the APM and SDS treatments left peptide fragments or the proteins adsorbed on the surfaces, whereas the other methods successfully removed the proteins. The QCM-D measurements indicated that in the removal treatments, fibrinogen was slowly adsorbed in the first cycle because of the change in surface wettability revealed by contact angle measurements. The SDS treatment was not effective in removing proteins. The APM or UV treatment decreased the frequency shifts for the reused HAp sensors. The UV/APM treatment did not induce the frequency shifts but decreased the dissipation shifts. Therefore, we conclude that the APM/UV treatment is the most useful method for reproducing protein adsorption behavior on HAp sensors.
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| 2. |
- Donnadieu, P., et al.
(författare)
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Deformation at ambient and high temperature of in situ Laves phases-ferrite composites
- 2014
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- The mechanical behavior of a Fe80Zr10Cr10 alloy has been studied at ambient and high temperature. This Fe 80Zr10Cr10 alloy, whoose microstructure is formed by alternate lamellae of Laves phase and ferrite, constitutes a very simple example of an in situ CMA phase composite. The role of the Laves phase type was investigated in a previous study while the present work focuses on the influence of the microstructure length scale owing to a series of alloys cast at different cooling rates that display microstructures with Laves phase lamellae width ranging from ∼50 nm to ∼150 nm. Room temperature compression tests have revealed a very high strength (up to 2 GPa) combined with a very high ductility (up to 35%). Both strength and ductility increase with reduction of the lamella width. High temperature compression tests have shown that a high strength (900 MPa) is maintained up to 873 K. Microstructural study of the deformed samples suggests that the confinement of dislocations in the ferrite lamellae is responsible for strengthening at both ambient and high temperature. The microstructure scale in addition to CMA phase structural features stands then as a key parameter for optimization of mechanical properties of CMA in situ composites. © 2014 National Institute for Materials Science.
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| 3. |
- Li, Duan, et al.
(författare)
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Rapid sintering of silicon nitride foams decorated with one-dimensional nanostructures by intense thermal radiation
- 2014
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 15:4
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Tidskriftsartikel (refereegranskat)abstract
- Silicon nitride foams were prepared by direct foaming and subsequent rapid sintering at 1600 °C. The intense thermal radiation generated under the pressureless spark plasma sintering condition facilitated necking of Si3N4 grains. The prepared foams possessed a porosity of ~80 vol% and a compressive strength of ~10 MPa, which required only ~30 min for the entire sintering processes. Rapid growth of one-dimensional SiC nanowires from the cell walls was also observed. Thermodynamic calculations indicated that the vapor–liquid–solid model is applicable to the formation of SiC nanowires under vacuum.
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| 4. |
- Salamon, David, et al.
(författare)
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Can the use of pulsed direct current induce oscillation in the applied pressure during spark plasma sintering?
- 2012
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 13:1, s. 015005-
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Tidskriftsartikel (refereegranskat)abstract
- The spark plasma sintering (SPS) process is known for its rapid densification of metals and ceramics. The mechanism behind this rapid densification has been discussed during the last few decades and is yet uncertain. During our SPS experiments we noticed oscillations in the applied pressure, related to a change in electric current. In this study, we investigated the effect of pulsed electrical current on the applied mechanical pressure and related changes in temperature. We eliminated the effect of sample shrinkage in the SPS setup and used a transparent quartz die allowing direct observation of the sample. We found that the use of pulsed direct electric current in our apparatus induces pressure oscillations with the amplitude depending on the current density. While sintering Ti samples we observed temperature oscillations resulting from pressure oscillations, which we attribute to magnetic forces generated within the SPS apparatus. The described current-pressure-temperature relations might increase understanding of the SPS process.
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| 5. |
- Terada, Dohiko, et al.
(författare)
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Transient charge-masking effect of applied voltage on electrospinning of pure chitosan nanofibers from aqueous solutions
- 2012
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Ingår i: Science and Technology of Advanced Materials. - : IOP Science. - 1468-6996 .- 1878-5514. ; 13:1, s. 015003-
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Tidskriftsartikel (refereegranskat)abstract
- The processing of a polyelectrolyte (whose functionality is derived from its ionized functional groups) into a nanofiber may improve its functionality and yield multiple functionalities. However, the electrospinning of nanofibers from polyelectrolytes is imperfect because polyelectrolytes differ considerably from neutral polymers in their rheological properties. In our study, we attempt to solve this problem by applying a voltage of opposite polarity to charges on a polyelectrolyte. The application of this 'countervoltage' can temporarily mask or screen a specific rheological property of the polyelectrolyte, making it behave as a neutral polymer. This approach can significantly contribute to the development of new functional nanofiber materials.
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| 6. |
- Tuoriniemi, Jani, 1982, et al.
(författare)
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Intermethod comparison of the particle size distributions of colloidal silica nanoparticles
- 2014
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- There can be a large variation in the measured diameter of nanoparticles depending on which method is used. In this work, we have strived to accurately determine the mean particle diameter of 3040 nm colloidal silica particles by using six different techniques. A quantitative agreement between the particle size distributions was obtained by scanning electron microscopy (SEM), and electrospray-scanning mobility particle sizer (ES SMPS). However, transmission electron microscopy gave a distribution shifted to smaller sizes. After confirming that the magnification calibration was consistent, this was attributed to sample preparation artifacts. The hydrodynamic diameter, d(h), was determined by dynamic light scattering (DLS) both in batch mode, and hyphenated with sedimentation field flow fractionation. Surprisingly the dh were smaller than the SEM, and ES SMPS diameters. A plausible explanation for the smaller sizes found with DLS is that a permeable gel layer forms on the particle surface. Results from nanoparticle tracking analysis were strongly biased towards larger diameters, most likely because the silica particles provide low refractive index contrast. Calculations confirmed that the sensitivity is, depending on the shape of the laser beam, strongly size dependent for particles with diameters close to the visualization limit.
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| 7. |
- Werheit, Helmut, et al.
(författare)
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Raman effect in icosahedral boron-rich solids
- 2010
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 11:2, s. 023001-
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Forskningsöversikt (refereegranskat)abstract
- We present Raman spectra of numerous icosahedral boron-rich solids having the structure of alpha-rhombohedral, beta-rhombohedral, alpha-tetragonal, beta-tetragonal, YB66, orthorhombic or amorphous boron. The spectra were newly measured and, in some cases, compared with reported data and discussed. We emphasize the importance of a high signal-to-noise ratio in the Raman spectra for detecting weak effects evoked by the modification of compounds, accommodation of interstitial atoms and other structural defects. Vibrations of the icosahedra, occurring in all the spectra, are interpreted using the description of modes in a-rhombohedral boron by Beckel et al. The Raman spectrum of boron carbide is largely clarified. Relative intra- and inter-icosahedral bonding forces are estimated for the different structural groups and for vanadium-doped beta-rhombohedral boron. The validity of Badger's rule is demonstrated for the force constants of inter-icosahedral B-B bonds, whereas the agreement is less satisfactory for the intra-icosahedral B-B bonds.
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| 8. |
- Amin, Muhammad, 1979, et al.
(författare)
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Low temperature and cost-effective growth of vertically aligned carbon nanofibers using spin-coated polymer-stabilized palladium nanocatalysts
- 2015
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- We describe a fast and cost-effective process for the growth of carbon nanofibers (CNFs) at a temperature compatible with complementary metal oxide semiconductor technology, using highly stable polymer-Pd nanohybrid colloidal solutions of palladium catalyst nanoparticles (NPs). Two polymer-Pd nanohybrids, namely poly(lauryl methacrylate)-block-poly((2-acetoacetoxy) ethyl methacrylate)/Pd (LauMA(x)-b-AEMA(y)/Pd) and polyvinylpyrrolidone/Pd were prepared in organic solvents and spin-coated onto silicon substrates. Subsequently, vertically aligned CNFs were grown on these NPs by plasma enhanced chemical vapor deposition at different temperatures. The electrical properties of the grown CNFs were evaluated using an electrochemical method, commonly used for the characterization of supercapacitors. The results show that the polymer-Pd nanohybrid solutions offer the optimum size range of palladium catalyst NPs enabling the growth of CNFs at temperatures as low as 350 degrees C. Furthermore, the CNFs grown at such a low temperature are vertically aligned similar to the CNFs grown at 550 degrees C. Finally the capacitive behavior of these CNFs was similar to that of the CNFs grown at high temperature assuring the same electrical properties thus enabling their usage in different applications such as on-chip capacitors, interconnects, thermal heat sink and energy storage solutions.
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| 9. |
- Baruah, S., et al.
(författare)
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Growth of ZnO nanowires on nonwoven polyethylene fibers
- 2008
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Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis. - 1468-6996 .- 1878-5514. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- We report the growth of ZnO nanowires on nonwoven polyethylene fibers using a simple hydrothermal method at a temperature below the boiling point of water. The ZnO nanowires were grown from seed ZnO nanoparticles affixed onto the fibers. The seed ZnO nanoparticles, with diameters of about 6-7 nm, were synthesized in isopropanol by reducing zinc acetate hydrate with sodium hydroxide. The growth process was carried out in a sealed chemical bath containing an equimolar solution of zinc nitrate hexahydrate and hexamethylene tetramine at a temperature of 95°C over a period of up to 20 h. The thickness and length of the nanowires can be controlled by using different concentrations of the starting reactants and growth durations. A 0.5 mM chemical bath yielded nanowires with an average diameter of around 50 nm, while a 25 mM bath resulted in wires with a thickness of up to about 1 μm. The length of the wires depends both on the concentration of the precursor solution as well as the growth duration, and in 20 h, nanowires as long as 10 μm can be grown. The nonwoven mesh of polyethylene fibers covered with ZnO nanowires can be used for novel applications such as water treatment by degrading pollutants by photocatalysis. Photocatalysis tests carried out on standard test contaminants revealed that the polyethylene fibers with ZnO nanowires grown on them could accelerate the photocatalytic degradation process by a factor of 3.
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| 10. |
- Baruah, S., et al.
(författare)
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Hydrothermal growth of ZnO nanostructures
- 2009
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Ingår i: Science and Technology of Advanced Materials. - : 2009 National Institute for Materials Science. - 1468-6996 .- 1878-5514. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- One-dimensional nanostructures exhibit interesting electronic and optical properties due to their low dimensionality leading to quantum confinement effects. ZnO has received lot of attention as a nanostructured material because of unique properties rendering it suitable for various applications. Amongst the different methods of synthesis of ZnO nanostructures, the hydrothermal method is attractive for its simplicity and environment friendly conditions. This review summarizes the conditions leading to the growth of different ZnO nanostructures using hydrothermal technique. Doping of ZnO nanostructures through hydrothermal method are also highlighted.
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| 11. |
- Baruah, S., et al.
(författare)
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Photocatalytic paper using zinc oxide nanorods
- 2010
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Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis. - 1468-6996 .- 1878-5514. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- Zinc oxide (ZnO) nanorods were grown on a paper support prepared from soft wood pulp. The photocatalytic activity of a sheet of paper with ZnO nanorods embedded in its porous matrix has been studied. ZnO nanorods were firmly attached to cellulose fibers and the photocatalytic paper samples were reused several times with nominal decrease in efficiency. Photodegradation of up to 93% was observed for methylene blue in the presence of paper filled with ZnO nanorods upon irradiation with visible light at 963 Wm–2 for 120 min. Under similar conditions, photodegradation of approximately 35% was observed for methyl orange. Antibacterial tests revealed that the photocatalytic paper inhibits the growth of Escherichia coli under room lighting conditions.
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| 12. |
- Baruah, S., et al.
(författare)
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Zinc stannate nanostructures : Hydrothermal synthesis
- 2011
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Ingår i: Science and Technology of Advanced Materials. - : Institute of Physics (IOP). - 1468-6996 .- 1878-5514. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Nanostructured binary semiconducting metal oxides have received much attention in the last decade owing to their unique properties rendering them suitable for a wide range of applications. In the quest to further improve the physical and chemical properties, an interest in ternary complex oxides has become noticeable in recent times. Zinc stannate or zinc tin oxide (ZTO) is a class of ternary oxides that are known for their stable properties under extreme conditions, higher electron mobility compared to its binary counterparts and other interesting optical properties. The material is thus ideal for applications from solar cells and sensors to photocatalysts. Among the different methods of synthesizing ZTO nanostructures, the hydrothermal method is an attractive green process that is carried out at low temperatures. In this review, we summarize the conditions leading to the growth of different ZTO nanostructures using the hydrothermal method and delve into a few of its applications reported in the literature.
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| 13. |
- Faure, Bertrand, et al.
(författare)
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Dispersion and surface functionalization of oxide nanoparticles for transparent photocatalytic and UV-protecting coatings and sunscreens
- 2013
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- This review describes recent efforts on the synthesis, dispersion and surface functionalization of the three dominating oxide nanoparticles used for photocatalytic, UV-blocking and sunscreen applications: titania, zinc oxide, and ceria. The gas phase and liquid phase synthesis is described briefly and examples are given of how weakly aggregated photocatalytic or UV-absorbing oxide nanoparticles with different composition, morphology and size can be generated. The principles of deagglomeration are reviewed and the specific challenges for nanoparticles highlighted. The stabilization of oxide nanoparticles in both aqueous and non-aqueous media requires a good understanding of the magnitude of the interparticle forces and the surface chemistry of the materials. Quantitative estimates of the Hamaker constants in various media and measurements of the isoelectric points for the different oxide nanoparticles are presented together with an overview of different additives used to prepare stable dispersions. The structural and chemical requirements and the various routes to produce transparent photocatalytic and nanoparticle-based UV-protecting coatings, and UV-blocking sunscreens are described and discussed.
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| 14. |
- Panigrahi, Puspamitra, et al.
(författare)
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Crafting ferromagnetism in Mn-doped MgO surfaces with p-type defects
- 2014
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 15:3, s. 035008-
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Tidskriftsartikel (refereegranskat)abstract
- We have employed first-principles calculations based on density functional theory (DFT) to investigate the underlying physics of unusual magnetism in Mn-doped MgO surface. We have studied two distinct scenarios. In the first one, two Mn atoms are substitutionally added to the surface, occupying the Mg sites. Both are stabilized in the Mn3+ valence state carrying a local moment of 4.3 mu(B) having a high-spin configuration. The magnetic interaction between the local moments display a very short-ranged characteristic, decaying very quickly with distance, and having antiferromagnetic ordering lower in energy. The energetics analysis also indicates that the Mn ions prefer to stay close to each other with an oxygen atom bridging the local interaction. In the second scenario, we started exploring the effect of native defects on the magnetism by crafting both Mg and O vacancies, which are p-and n-type defects, respectively. It is found that the electrons and holes affect the magnetic interaction between Mn ions in a totally different manner. The n-type defect leads to very similar magnetism, with the AFM configuration being energetically preferred. However, in the presence of Mg vacancy, the situation is quite different. The Mn atoms are further oxidized, giving rise to mixed Mn(d) ionic states. As a consequence, the Mn atoms couple ferromagnetically, when placed in the close configuration, and the obtained electronic structure is coherent with the double-exchange type of magnetic interaction. To guarantee the robustness of our results, we have benchmarked our calculations with three distinct theory levels, namely DFT-GGA, DFT-GGA+U and DFT-hybrid functionals. On the surface, the Mg vacancy displays lower formation energy occurring at higher concentrations. Therefore, our model systems can be the basis to explain a number of controversial results regarding transition metal doped oxides.
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| 15. |
- Wetterskog, Erik, et al.
(författare)
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Precise control over shape and size of iron oxide nanocrystals suitable for assembly into ordered particle arrays
- 2014
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 15:5
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Tidskriftsartikel (refereegranskat)abstract
- Here we demonstrate how monodisperse iron oxide nanocubes and nanospheres with average sizes between 5 and 27 nm can be synthesized by thermal decomposition. The relative importance of the purity of the reactants, the ratio of oleic acid and sodium oleate, the maximum temperature, and the rate of temperature increase, on robust and reproducible size and shape-selective iron oxide nanoparticle synthesis are identified and discussed. The synthesis conditions that generate highly monodisperse iron oxide nanocubes suitable for producing large ordered arrays, or mesocrystals are described in detail.
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| 16. |
- Cao, Danfeng, et al.
(författare)
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Electrochemical control of bone microstructure on electroactive surfaces for modulation of stem cells and bone tissue engineering
- 2023
-
Ingår i: Science and Technology of Advanced Materials. - : TAYLOR & FRANCIS LTD. - 1468-6996 .- 1878-5514. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Controlling stem cell behavior at the material interface is crucial for the development of novel technologies in stem cell biology and regenerative medicine. The composition and presentation of bio-factors on a surface strongly influence the activity of stem cells. Herein, we designed an electroactive surface that mimics the initial process of trabecular bone formation, by immobilizing chondrocyte-derived plasma membrane nanofragments (PMNFs) on its surface for rapid mineralization within 2 days. Moreover, the electroactive surface was based on the conducting polymer polypyrrole (PPy), which enabled dynamic control of the presentation of PMNFs on the surface via electrochemical redox switching, further resulting in the formation of bone minerals with different morphologies. Furthermore, bone minerals with contrasting surface morphologies had differential effects on the differentiation of human bone marrow-derived stem cells (hBMSCs) cultured on the surface. Together, this electroactive surface showed multifunctional characteristics, not only allowing dynamic control of PMNF presentation but also promoting the formation of bone minerals with different morphologies within 2 days. This electroactive substrate could be valuable for more precise control of stem cell growth and differentiation, and further development of more suitable microenvironments containing bone apatite for housing a bone marrow stem cell niche, such as biochips/bone-on-chips.
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| 17. |
- Charinpanitkul, T., et al.
(författare)
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Effects of cosurfactant on ZnS nanoparticle synthesis in microemulsion
- 2005
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Ingår i: Science and Technology of Advanced Materials. - : Institute of Physics (IOP). - 1468-6996 .- 1878-5514. ; 6:3-4 SPEC. ISS., s. 266-271
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Tidskriftsartikel (refereegranskat)abstract
- ZnS nanoparticles with different morphology; spherical, ellipsoidal particles' nanotubes and nanorods, could be successfully synthesized from quaternary W/O microemulsion system. The morphology of the final products could be clearly confirmed by the scanning electron microscopy (SEM) and the transmission electron microscopy (TEM). The effect of cosurfactant on size and morphology of the obtained products have been explored in this work. The key controlling parameters such as the molar ratio of water to surfactant (wo) and the reactant concentration, which affect the product characteristics, have also been investigated.
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| 18. |
- Jacob, Stephane, et al.
(författare)
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High-performance flexible thermoelectric modules based on high crystal quality printed TiS2/hexylamine
- 2021
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Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis Ltd. - 1468-6996 .- 1878-5514. ; 22:1, s. 907-916
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Tidskriftsartikel (refereegranskat)abstract
- Printed electronics implies the use of low-cost, scalable, printing technologies to fabricate electronic devices and circuits on flexible substrates, such as paper or plastics. The development of this new electronic is currently expanding because of the emergence of the internet-of-everything. Although lot of attention has been paid to functional inks based on organic semiconductors, another class of inks is based on nanoparticles obtained from exfoliated 2D materials, such as graphene and metal sulfides. The ultimate scientific and technological challenge is to find a strategy where the exfoliated nanoparticle flakes in the inks can, after solvent evaporation, form a solid which displays performances equal to the single crystal of the 2D material. In this context, a printed layer, formed from an ink composed of nano-flakes of TiS2 intercalated with hexylamine, which displays thermoelectric properties superior to organic intercalated TiS2 single crystals, is demonstrated for the first time. The choice of the fraction of exfoliated nano-flakes appears to be a key to the forming of a new self-organized layered material by solvent evaporation. The printed layer is an efficient n-type thermoelectric material which complements the p-type printable organic semiconductors The thermoelectric power factor of the printed TiS2/hexylamine thin films reach record values of 1460 mu W m(-1) K-2 at 430 K, this is considerably higher than the high value of 900 mu W m(-1) K-2 at 300 K reported for a single crystal. A printed thermoelectric generator based on eight legs of TiS2 confirms the high-power factor values by generating a power density of 16.0 W m(-2) at Delta T = 40 K.
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| 19. |
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| 20. |
- Matthiesen, Isabelle, et al.
(författare)
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Astrocyte 3D culture and bioprinting using peptide functionalized hyaluronan hydrogels
- 2023
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Astrocytes play an important role in the central nervous system, contributing to the development of and maintenance of synapses, recycling of neurotransmitters, and the integrity and function of the blood-brain barrier. Astrocytes are also linked to the pathophysiology of various neurodegenerative diseases. Astrocyte function and organization are tightly regulated by interactions mediated by the extracellular matrix (ECM). Engineered hydrogels can mimic key aspects of the ECM and can allow for systematic studies of ECM-related factors that govern astrocyte behaviour. In this study, we explore the interactions between neuroblastoma (SH-SY5Y) and glioblastoma (U87) cell lines and human fetal primary astrocytes (FPA) with a modular hyaluronan-based hydrogel system. Morphological analysis reveals that FPA have a higher degree of interactions with the hyaluronan-based gels compared to the cell lines. This interaction is enhanced by conjugation of cell-adhesion peptides (cRGD and IKVAV) to the hyaluronan backbone. These effects are retained and pronounced in 3D bioprinted structures. Bioprinted FPA using cRGD functionalized hyaluronan show extensive and defined protrusions and multiple connections between neighboring cells. Possibilities to tailor and optimize astrocyte-compatible ECM-mimicking hydrogels that can be processed by means of additive biofabrication can facilitate the development of advanced tissue and disease models of the central nervous system.
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| 21. |
- Nilsson Ekdahl, Kristina, et al.
(författare)
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A human whole-blood model to study the activation of innate immunity system triggered by nanoparticles as a demonstrator for toxicity
- 2019
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Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis Group. - 1468-6996 .- 1878-5514. ; 20:1, s. 688-698
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Forskningsöversikt (refereegranskat)abstract
- In this review article, we focus on activation of the soluble components of the innate immune system triggered by nonbiological compounds and stress variances in activation due to the difference in size between nanoparticles (NPs) and larger particles or bulk material of the same chemical and physical composition. We then discuss the impact of the so-called protein corona which is formed on the surface of NPs when they come in contact with blood or other body fluids. For example, NPs which bind inert proteins, proteins which are prone to activate the contact system (e.g., factor XII), which may lead to clotting and fibrin formation or the complement system (e.g., IgG or C3), which may result in inflammation and vascular damage. Furthermore, we describe a whole blood model which we have developed to monitor activation and interaction between different components of innate immunity: blood protein cascade systems, platelets, leukocytes, cytokine generation, which are induced by NPs. Finally, we describe our own studies on innate immunity system activation induced by three fundamentally different species of NPs (two types of engineered NPs and diesel NPs) as demonstrator of the utility of an initial determination of the composition of the protein corona formed on NPs exposed to ethylenediaminetetraacetic acid (EDTA) plasma and subsequent analysis in our whole blood model. [GRAPHICS] .
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| 22. |
- Park, Taehyun, et al.
(författare)
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Interactive structural color displays of nano-architectonic 1-dimensional block copolymer photonic crystals FOCUS ISSUE REVIEW
- 2023
-
Ingår i: Science and Technology of Advanced Materials. - : TAYLOR & FRANCIS LTD. - 1468-6996 .- 1878-5514. ; 24:1
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Forskningsöversikt (refereegranskat)abstract
- For changing environmental circumstances, interactive structural color (SC) observation is a promising strategy to store and express external information. SCs based on self-assembled block copolymer (BCP) photonic crystals have been a research focus due to their facile and diverse nanostructures relying on the volume ratio of blocks. Their unique nano-architectonics can reflect incident light due to constructive interference of the two different dielectric constituents. Their excellent ability to change nano-architectonics in response to external stimuli (i.e. humidity, temperature, pH, and mechanical force) allows for a programmable and stimuli-interactive BCP SC display. In this review, recent advances in programmable and stimuli-interactive SC displays with the 1-dimensional self-assembled BCP nano-architectonics are comprehensively discussed. First, this review focuses on the development of programmable BCP SCs that can store various information. Second, stimuli-interactive BCP SCs capable of responding reversibly to external stimuli are also addressed. Particularly, reversible BCP SC changes are suitable for rewritable displays and emerging human-interactive BCP SC displays that detect various human information through changes in electric signals with the simultaneous alteration of the BCP SCs. Based on previously reported literature, the current challenges in this research field are further discussed, and the perspective for future development is presented in terms of material, nano-architectonics, and process.
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| 23. |
- Petsagkourakis, Ioannis, et al.
(författare)
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Thermoelectric materials and applications for energy harvesting power generation
- 2018
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Ingår i: Science and Technology of Advanced Materials. - : TAYLOR & FRANCIS LTD. - 1468-6996 .- 1878-5514. ; 19:1, s. 836-862
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Forskningsöversikt (refereegranskat)abstract
- Thermoelectrics, in particular solid-state conversion of heat to electricity, is expected to be a key energy harvesting technology to power ubiquitous sensors and wearable devices in the future. A comprehensive review is given on the principles and advances in the development of thermoelectric materials suitable for energy harvesting power generation, ranging from organic and hybrid organic-inorganic to inorganic materials. Examples of design and applications are also presented. [GRAPHICS] .
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| 24. |
- Pummakarnchana, O., et al.
(författare)
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Air pollution monitoring and GIS modeling : A new use of nanotechnology based solid state gas sensors
- 2005
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Ingår i: Science and Technology of Advanced Materials. - : Elsevier. - 1468-6996 .- 1878-5514. ; 6:3-4 SPEC. ISS., s. 251-255
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution is a serious problem in thickly populated and industrialized areas in Thailand, especially in Bangkok. The air pollution in Bangkok is abundant, especially in areas where pollution sources and the human population are concentrated. Economic growth and industrialization are proceeding at a rapid pace, accompanied by increasing emissions of air polluting sources. Furthermore, though the variety and quantities of polluting sources have increased dramatically, the development of a suitable method for monitoring the pollution causing sources has not followed at the same pace. Environmental impacts of air pollutants have impact on public health, vegetation, material deterioration etc. To prevent or minimize the damage caused by atmospheric pollution, suitable monitoring systems are urgently needed that can rapidly and reliably detect and quantify polluting sources for monitoring by regulating authorities in order to prevent further deterioration of the current pollution levels. Consequently, it is important that the current real-time air quality monitoring system, controlled by the Pollution Control Department (PCD), should be adapted or extended to aid in alleviating this problem. Nanotechnology has been applied to several industrial and domestic fields, for example, applications for gas monitoring systems, gas leak detectors in factories, fire and toxic gas detectors, ventilation control, breath alcohol detectors, and the like. Here we report an application example of studying air quality monitoring based on nanotechnology 'solid state gas sensors'. So as to carry out air pollution monitoring over an extensive area, a combination of ground measurements through inexpensive sensors and wireless GIS will be used for this purpose. This portable device, comprising solid state gas sensors integrated to a Personal Digital Assistant (PDA) linked through Bluetooth communication tools and Global Positioning System (GPS), will allow rapid dissemination of information on pollution levels at multiple sites simultaneously. The AQ report generated can be then published using Internet GIS to provide a real-time information service for the PCD, for increased public awareness and enhanced public participation. The local deterministic and geostatistical interpolation methods have been used for spatial prediction, and to find out the most suitable method for studying air pollution, based on observations at each monitoring site.
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| 25. |
- Richter-Dahlfors, Agneta, et al.
(författare)
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Fluorescent optotracers for bacterial and biofilm detection and diagnostics
- 2023
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 24:1
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Forskningsöversikt (refereegranskat)abstract
- Effective treatment of bacterial infections requires methods that accurately and quickly identify which antibiotic should be prescribed. This review describes recent research on the development of optotracing methodologies for bacterial and biofilm detection and diagnostics. Optotracers are small, chemically well-defined, anionic fluorescent tracer molecules that detect peptide- and carbohydrate-based biopolymers. This class of organic molecules (luminescent conjugated oligothiophenes) show unique electronic, electrochemical and optical properties originating from the conjugated structure of the compounds. The photophysical properties are further improved as donor-acceptor-donor (D-A-D)-type motifs are incorporated in the conjugated backbone. Optotracers bind their biopolymeric target molecules via electrostatic interactions. Binding alters the optical properties of these tracer molecules, shown as altered absorption and emission spectra, as well as ON-like switch of fluorescence. As the optotracer provides a defined spectral signature for each binding partner, a fingerprint is generated that can be used for identification of the target biopolymer. Alongside their use for in situ experimentation, optotracers have demonstrated excellent use in studies of a number of clinically relevant microbial pathogens. These methods will find widespread use across a variety of communities engaged in reducing the effect of antibiotic resistance. This includes basic researchers studying molecular resistance mechanisms, academia and pharma developing new antimicrobials targeting biofilm infections and tests to diagnose biofilm infections, as well as those developing antibiotic susceptibility tests for biofilm infections (biofilm-AST). By iterating between the microbial world and that of plants, development of the optotracing technology has become a prime example of successful cross-feeding across the boundaries of disciplines. As optotracers offers a capacity to redefine the way we work with polysaccharides in the microbial world as well as with plant biomass, the technology is providing novel outputs desperately needed for global impact of the threat of antimicrobial resistance as well as our strive for a circular bioeconomy.
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| 26. |
- Sugunan, A, et al.
(författare)
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Heavy-metal ion sensors using chitosan-capped gold nanoparticles
- 2005
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 6:3-4, s. 335-340
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Tidskriftsartikel (refereegranskat)abstract
- We report a novel strategy for using gold nanoparticles capped with chitosan for sensing ions of heavy metals. Acidic anions (glutamate ions in our case) are expected to cap the nanoparticle surfaces similar to conventional methods of stabilization of gold nanoparticles by citrate ions. The polycationic nature of chitosan enables attachment of the polymer to the negatively charged gold nanoparticle surfaces through electrostatic interactions. Use of chitosan serves dual purpose of providing sufficient steric hindrance ensuring stability of the colloid and also to functionalize the nanoparticles for use as sensors. The well-documented chelating properties of chitosan and the sensitivity of the optical properties of gold nanoparticles to agglomeration have been employed to detect low concentrations of heavy metals ions (Zn2+ and Cu2+) in water. A comparison of the optical absorption spectra of the colloidal suspension before and after exposure to metal ions is a good indicator of the concentration of the heavy metal ions.
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| 27. |
- Suzuki, Haruna, et al.
(författare)
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Impact of spontaneous liposome modification with phospholipid polymer-lipid conjugates on protein interactions
- 2022
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Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis Group. - 1468-6996 .- 1878-5514. ; 23:1, s. 845-857
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Tidskriftsartikel (refereegranskat)abstract
- Liposome surface coating has been studied to avoid the immunological responses caused by the complement system, and alternative materials to poly(ethylene glycol) (PEG) have been explored recently since the production of anti-PEG IgM antibodies has been found in humans. We previously reported a liposome coating with poly(2-methacryloyloxyethyl phosphorylcholine) (poly(MPC))-conjugated lipids (PMPC-lipids) and demonstrated its protective effect on blood protein interactions. Here, we attempted to modify the liposome surface by exogenously adding PMPC-lipids, which were spontaneously incorporated into the outer membrane via hydrophobic interactions. The polymerization degree of the PMPC segment was regulated from 10 to 100. The incorporated ratio of PMPC-lipid increased with a decrease in the degree of PMPC polymerization. Due to surface modification with PMPC-lipids, increase in the length of the PMPC-chain increased the size of the liposomes. The modified liposomes were kept stable for 14 d in terms of their size, polydispersity, and surface properties, where approximately 70% of PMPC-lipids were incorporated into the liposome surface. We demonstrated that liposome surface modification with PMPC-lipids can inhibit protein adsorption when exposed to serum, regardless of the degree of polymerization of PMPC. In addition, the PMPC-lipid modified surface was not recognized by the anti-PEG IgM antibody, whereas PEG-lipid was recognized by the antibody. Thus, we successfully fabricated an inert liposome surface via spontaneous modification with PMPC-lipids, where only the outer bilayer surface was modified. This technique can be available for full loading of water-soluble active pharmaceutical ingredient inside the modified liposome.
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| 28. |
- Ueki, Takayuki, et al.
(författare)
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Fast and selective cell isolation from blood sample by microfiber fabric system with vacuum aspiration
- 2016
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 17:1, s. 807-815
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Tidskriftsartikel (refereegranskat)abstract
- Since circulating tumor cells (CTCs) are tumor cells which are found in the blood of cancer patients, CTCs are potential tumor markers, so a rapid isolation of CTCs is desirable for clinical applications. In this paper, a three-dimensional polystyrene (PS) microfiber fabric with vacuum aspiration system was developed for capturing CTCs within a short time. Various microfiber fabrics with different diameters were prepared by the electrospinning method and optimized for contact frequency with cells. Vacuum aspiration utilizing these microfiber fabrics could filter all cells within seconds without mechanical damage. The microfiber fabric with immobilized anti-EpCAM antibodies was able to specifically capture MCF-7 cells that express EpCAM on their surfaces. The specificity of the system was confirmed by monitoring the ability to isolate MCF-7 cells from a mixture containing CCRF-CEM cells that do not express EpCAM. Furthermore, the selective capture ability of the microfiber was retained even when the microfiber was exposed to the whole blood of pigs spiked with MCF-7 cells. The specific cell capture ratio of the vacuum aspiration system utilizing microfiber fabric could be improved by increasing the thickness of the microfiber fabric through electrospinning time.
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| 29. |
- Ukleev, Victor, et al.
(författare)
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Observation by SANS and PNR of pure Néel-type domain wall profiles and skyrmion suppression below room temperature in magnetic [Pt/CoFeB/Ru]10 multilayers
- 2024
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Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis. - 1468-6996 .- 1878-5514. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- We report investigations of the magnetic textures in periodic multilayers [Pt(1 nm)/(CoFeB(0.8 nm)/Ru(1.4 nm)]10 using polarised neutron reflectometry (PNR) and small-angle neutron scattering (SANS). The multilayers are known to host skyrmions stabilized by Dzyaloshinskii-Moriya interactions induced by broken inversion symmetry and spin–orbit coupling at the asymmetric interfaces. From depth-dependent PNR measurements, we observed well-defined structural features and obtained the layer-resolved magnetization profiles. The in-plane magnetization of the CoFeB layers calculated from fitting of the PNR profiles is found to be in excellent agreement with magnetometry data. Using SANS as a bulk probe of the entire multilayer, we observe long-period magnetic stripe domains and skyrmion ensembles with full orientational disorder at room temperature. No sign of skyrmions is found below 250 K, which we suggest is due to an increase of an effective magnetic anisotropy in the CoFeB layer on cooling that suppresses skyrmion stability. Using polarised SANS at room temperature, we prove the existence of pure Néel-type windings in both stripe domain and skyrmion regimes. No Bloch-type winding admixture, i.e. an indication for hybrid windings, is detected within the measurement sensitivity, in good agreement with expectations according to our micromagnetic modelling of the multilayers. Our findings using neutron techniques provide valuable microscopic insights into the rich magnetic behavior of skyrmion-hosting multilayers, which are essential for the advancement of future skyrmion-based spintronic devices.
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| 30. |
- Warad, H. C., et al.
(författare)
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Luminescent nanoparticles of Mn doped ZnS passivated with sodium hexametaphosphate
- 2005
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Ingår i: Science and Technology of Advanced Materials. - : Elsevier. - 1468-6996 .- 1878-5514. ; 6:3-4 SPEC. ISS., s. 296-301
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Tidskriftsartikel (refereegranskat)abstract
- We report the synthesis of luminescent nanoparticles of manganese doped zinc sulfide (ZnS:Mn2+) with an emission peak at around 590 nm. Nanoparticles of ZnS:Mn2+ are prepared by a co-precipitation reaction from homogenous solutions of zinc and manganese salts. Based on Ostwald ripening and surface passivation, we discuss a mechanism for the formation of ZnS:Mn2+ nanoparticles. The reaction proceeds with the nucleation of ZnS crystals, which are immediately passivated by the anions in the solution. This in turn attracts cations including zinc and manganese which contribute to the growth of the crystal. These nanoparticles are sterically stabilized using polyphosphates of sodium namely sodium tripolyphosphate (STTP) and sodium hexametaphosphate (SHMP). The nanoparticles consist of particles of 60-80 nm in diameter, each containing primary crystallites that was estimated from the X-ray diffraction patterns to be at around 2.2 nm
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| 31. |
- Yu, Xiaoshuang, et al.
(författare)
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Organic Eu3+-complex-anchored porous diatomite channels enable UV protection and down conversion in hybrid material
- 2020
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Ingår i: Science and Technology of Advanced Materials. - : TAYLOR & FRANCIS LTD. - 1468-6996 .- 1878-5514. ; 21:1, s. 726-736
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Tidskriftsartikel (refereegranskat)abstract
- The organic Eu3+-complex [Eu(TTA)(3)Phen] has been incorporated into the channels of surface-modified frustules from diatoms as a key material to absorb and convert UV-photons to visible luminescence. Systematic investigation results indicate that the organic Eu3+-complex encapsulated in the functionalized diatomite channels exhibits enhanced luminescence and longer lifetime, owning to the Eu(TTA)(3)Phen complex interacting with its surrounding silylating agents. The organic Eu3+-complex-anchored porous diatomite hybrid luminescent material was compounded with polyethylene terephthalate (PET) by using a mini-twin screw extruder to prepare a self-supporting film of the hybrid material. Besides, the UV absorption properties of the composite films were investigated. These films will potentially be related to the UV protection of photovoltaic devices.
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| 32. |
- Zhang, Liming, et al.
(författare)
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Spheronized drug microcarrier system from canola straw lignin
- 2023
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Ingår i: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Inhomogeneous lignin from a canola (rapeseed) straw was isolated and valorized as regularly shaped spherical microparticles for drug delivery formulations. Lignin with a purity of 83% and broad molecular weight distribution ( > 5.0) was extracted by alkali pulping and acetylated to increase spheronization ability. Lignins with high degrees of acetylation (0.76 and 0.89) were successfully assembled into microparticles with uniform sizes (approximately 2 mu m) and smooth spherical surfaces via solvent-antisolvent precipitation. Hydrophobic coumarin 153 and positively charged ciprofloxacin were used as model drugs to assess the encapsulation and release performance of lignin microparticles. Highly acetylated lignin microparticles displayed encapsulation efficiencies of 89.6% for coumarin 153% and 90.6% for ciprofloxacin. Scanning electron microscope images showed that coumarin 153 was encapsulated in the hydrophobic core, while ciprofloxacin was adsorbed on the less hydrophobic shell. The synthesis of lignin microcarriers not only provides a facile approach to utilizing waste canola straw lignin for drug delivery matrices but also has the potential to serve as an alternative lignin powder feedstock for bio-based materials.
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| 33. |
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