Nano-TiO2-SiO2 powder as inorganic support for hybrid pigment preparation

A study was made of the adsorption of three selected food dyes (C.I. Food Black 1, C.I. Food Brown 3 and C.I. Food Green 4) on the surface of an inorganic, synthetic TiO₂-SiO₂ support of anatase form. This produces new hybrid pigments having desirable physicochemical and functional properties due to the presence in their structure of the TiO₂-SiO₂ support. The process of adsorption was conducted for dye concentrations ranging from 10 to 50 mg/dm³. The physicochemical properties of the inorganic support and the resulting hybrid pigments were determined. The characterisation included determination of the dispersion and morphology of the systems (particle size distribution, SEM images), porous structure parameters (BET isotherms) and electrokinetic properties (zeta potential and electrophoretic mobility), as well as thermal stability and colorimetric parameters. The efficiency of food dye adsorption on TiO₂-SiO₂ was examined, and the degree of coverage of the inorganic support with the food dyes was also estimated based on elemental analysis results. The results were used to evaluate the quality of the functional hybrid pigments obtained using selected food dyes and TiO₂-SiO₂ support, and to determine how the adsorption efficiency is affected by the dye structure. Selected diazo food dyes were more effectively adsorbed on the surface of the synthetic TiO₂-SiO₂ support. The hybrid pigments obtained have desirable physicochemical and functional properties. The synthesised food dye/TiO₂-SiO₂ hybrids may be used in pharmaceutical products.     

Poly(ε-caprolactone)-based membranes with tunable physicochemical,bioactive and osteoinductive properties

In contrast to currently used materials, membranes for the treatment of bone defects should actively promote regeneration of bone tissue beyond their physical barrier function. What is more, both material properties and biological features of membranes should be easily adaptable to meet the needs of particular therapeutic applications. Therefore, the role of preparation methods (non-solvent-induced phase separation and thermal-induced phase separation) of poly(ε-caprolactone)-based membranes and their modification with gel-derived bioactive glass (BG) particles of two different sizes (<45 and <3 μm) in modulating material morphology, polymer matrix crystallinity, surface wettability, kinetics of in vitro bioactivity and also osteoblast response was investigated. Both surfaces of membranes were characterised in terms of their properties. Our results indicated a possibility to modulate microstructure (pore size ranging from submicron to hundreds of micrometres), wettability (from hydrophobic to fully wettable surface) and polymer crystallinity (from 19 to 60%) in a wide range by the use of various preparation methods and different BG particle sizes. Obtained composite membranes showed excellent in vitro hydroxyapatite forming ability after incubation in simulated body fluid. Here we demonstrated that bioactive layer formation on the surface of membranes occurred through ACP–OCP–CDHA–HCA transformation, that mimic in vivo bone biomineralization process. Composite membranes supported human osteoblast proliferation, stimulated cell differentiation and matrix mineralization. We proved that kinetics of bioactivity process and also osteoinductive properties of membranes can be easily modulated with the use of proposed variables. This brings new opportunities to obtain multifunctional membranes for bone regeneration with tunable physicochemical and biological properties.     

Electrocatalytic oxidation of methanol,ethylene glycol and glycerine in alkaline media on TiO2 nanotubes decorated with AuCu nanoparticles for an application in fuel cells

Journal of Materials Science - In this work, we present the catalytic and photocatalytic activity of AuCu nanostructures obtained on TiO2 nanotubes toward methanol, ethylene glycol and glycerine...     

Sintering behavior and microstructure evolution in cp-titanium processed by spark plasma sintering

This paper investigates the effect of various sintering temperatures from 800 to 1500?°C on the microstructure evolution of cp-titanium processed by Spark Plasma Sintering (SPS). The material processing conditions under consideration may change the obtained atomic order and microstructure. The different relation of the mechanical and corrosion resistance properties observed in the analyzed results could at the same time be shaped in the expected range. The SPS procedure allows the obtainment of nearly theoretical densities of the compacts and excellent mechanical properties (UTS?=?892?MPa, CS?=?1442?MPa). The results confirm that the contact angle measurement could support the process control, particularly if a microstructure feature is considered.     

An Ultrastable Ionic Chemiresistor Skin with an Intrinsically Stretchable Polymer Electrolyte

Ultrastable sensing characteristics of the ionic chemiresistor skin (ICS) that is designed by using an intrinsically stretchable thermoplastic polyurethane electrolyte as a volatile organic compound (VOC) sensing channel are described. The hierarchically assembled polymer electrolyte film is observed to be very uniform, transparent, and intrinsically stretchable. Systematic experimental and theoretical studies also reveal that artificial ions are evenly distributed in polyurethane matrix without microscale phase separation, which is essential for implementing high reliability of the ICS devices. The ICS displays highly sensitive and stable sensing of representative VOCs (including toluene, hexane, propanal, ethanol, and acetone) that are found in the exhaled breath of lung cancer patients. In particular, the sensor is found to be fully operational even after being subjected to long‐term storage or harsh environmental conditions (relative humidity of 85% or temperature of 100 °C) or severe mechanical deformation (bending to a radius of curvature of 1 mm, or stretching strain of 100%), which can be an effective method to realize a human‐adaptive and skin‐attachable biosensor platform for daily use and early diagnosis.     

Increased Exciton Delocalization of Polymer upon Blending with Fullerene

Interfaces between donor and acceptor in a polymer solar cell play a crucial role in exciton dissociation and charge photogeneration. While the importance of charge transfer (CT) excitons for free carrier generation is intensively studied, the effect of blending on the nature of the polymer excitons in relation to the blend nanomorphology remains largely unexplored. In this work, electroabsorption (EA) spectroscopy is used to study the excited‐state polarizability of polymer excitons in several polymer:fullerene blend systems, and it is found that excited‐state polarizability of polymer excitons in the blends is a strong function of blend nanomorphology. The increase in excited‐state polarizability with decreased domain size indicates that intermixing of states at the interface between the donor polymers and fullerene increases the exciton delocalization, resulting in an increase in exciton dissociation efficiency. This conclusion is further supported by transient absorption spectroscopy and time‐resolved photoluminescence measurements, along with the results from time‐dependent density functional theory calculations. These findings indicate that polymer excited‐state polarizability is a key parameter for efficient free carrier generation and should be considered in the design and development of high‐performance polymer solar cells.     

Dynamic Nanostructures from DNA‐Coupled Molecules,Polymers, and Nanoparticles

Dynamic and reconfigurable systems that can sense and react to physical and chemical signals are ubiquitous in nature and are of great interest in diverse areas of science and technology. DNA is a powerful tool for fabricating such smart materials and devices due to its programmable and responsive molecular recognition properties. For the past couple of decades, DNA‐based self‐assembly is actively explored to fabricate various DNA–organic and DNA–inorganic hybrid nanostructures with high‐precision structural control. Building upon past development, researchers have recently begun to design and assemble dynamic nanostructures that can undergo an on‐demand transformation in the structure, properties, and motion in response to various external stimuli. In this Review, recent advances in dynamic DNA nanostructures, focusing on hybrid structures fabricated from DNA‐conjugated molecules, polymers, and nanoparticles, are introduced, and their potential applications and future perspectives are discussed.     

The possibility of renal function recovery in chronic hemodialysis patients should not be overlooked: Single center experience

Chronic hemodialysis is implemented when irreversible loss of kidney function occurs. Sometimes renal recovery is overlooked. From January 2005 to December 2014, we identified 28 patients hemodialyzed for more than 3 months who had renal replacement therapy discontinued. The group consisted of 17 (57.7%) males and 11 (42.3%) females. Patients were 18–87 years old. Time of hemodialysis ranged from 3 to 97 months. Of note, 14 (50%) patients were referred from local dialysis units for solution of vascular access problems. In 13 (46.2%) patients dialysis was abandoned within the first 6 months, in 5 (17.8%) patients between 6 and 12 months, and in 10 (35.7%) patients beyond 12 months. Estimated dialysis‐free survival was 94.4% (SE 0.054) and 82% (SE 0.095) at 12 and 24 months, respectively. All physicians must be aware of possible kidney function improvement. In patients with preserved diuresis fall in periodical urea or creatinine measurements might be a sign of renal recovery.     

Detection and response characteristics of giant magnetostrictive/piezoelectric laminated cantilevers under cyclic bending

We examine the detection and response characteristics of giant magnetostrictive/piezoelectric laminated cantilevers under cyclic bending in a combined numerical and experimental approach. The laminate is fabricated using thin Terfenol-D and PZT layers. Three-dimensional finite element analysis was conducted, and the dynamic electromagneto-mechanical fields in the two-layered magnetostrictive/piezoelectric laminate were predicted by introducing a second-order magnetoelastic constant of Terfenol-D. The tip deflection, induced voltage, and induced magnetic field were also measured, and experimental data were compared with numerical simulations to verify the model. The effects of load ratio and frequency on the dynamic electromagneto-mechanical fields were then discussed in detail. The finite element method is shown to be capable of estimating the dynamic electromagneto-mechanical fields in the giant magnetostrictive/piezoelectric laminated cantilevers, making it a useful tool for designing future electronic devices with self-sensing or energy harvesting capabilities.