Purification of rosmarinic acid extracts from Lavandula vera MM cell biomass

Two approaches for purification of rosmarinic acid extracts, obtained from Lavandula vera MM cell biomass were investigated: adsorption on different Amberlite XAD resins and extraction with ethylacetate. Results showed that when ethylacetate extraction was used, 18.7 times higher level of purity compared to initial material was achieved. Similarly the obtained preparations from adsorption on Amberlite XAD-7 resin and elution with 80% ethanol contained 29.8% rosmarinic acid, which is 7.7 times higher purity compared to initial material. The precipitation of rosmarinic acid as Ca-rosmarinate was investigated as well. The obtained rosmarinic acid preparations were with low yield (34% of rosmarinic acid fell into sediment).     

Towards Recyclable Nanoporous Polymer Membranes for the Synthesis of One-dimensional Nanoscale Gold Colloids

Proof-of-concept studies towards recyclable nanoporous track-etched polymer membranes for template-synthesis of one-dimensional colloidal gold rods indicate that surfactant-capped gold nanorods can be synthesised within and isolated from polyethylene terephthalate (Lavsan) membranes using organic solvents with or without sonication. Thereafter, the same Lavsan membrance can be re-used for at least one to two additional synthetic cycles. An erratum to this article can be found at     

Swelling Deswelling Behavior of PS‐PNIPAAM Copolymer Particles and PNIPAAM Brushes Grafted from Polystyrene Particles & Monoliths

Two sets of emulsion particles have been synthesized. In the first set, surfactant free emulsion was used to directly synthesize PS‐PNIPAAM copolymer particles. In the second set, polystyrene particles with an ATRP initiator shell were first synthesized and subsequently grafted with PNIPAAM brushes. Swelling/deswelling behavior of both sets of particles was studied with respect to temperature and time. Monoliths with two different porosities were also formed by grafting and crosslinking of PNIPAAM chains on the aggregated particles and characterized. In all cases, swelling kinetics is sufficiently fast to use these supports for separation driven by temperature changes only. However, hindrance and cross‐linking is sensibly reducing the material performance.

     

“True” biocomposites with biopolyesters and date seed powder: Mechanical,thermal, and degradation properties

Biopolymers have gained research focus due to enhanced property profiles as well as need to replace the fossil fuel based polymeric materials. The generation of biocomposites with functional biofillers can lead to further enhancement of their potential. In this study, composites of date seed powder with biopolyesters poly(butylene adipate‐co‐terephthalate) (PBAT) and poly‐l ‐lactide (PLA) have been demonstrated. The composites exhibited individual degradation peaks for the components in the thermogravimetric analysis (TGA), but still had suitable thermal performance confirmed by the dynamic TGA. The filler also modified the crystalline morphology of the polymers differently. The tensile modulus of the PBAT‐based composites had enhancement of more than 300% in the composite with 40% filler content. The PLA composites also enhanced the modulus marginally till 20% filler content, however, it was still significant due to the very high modulus of PLA as compared to PBAT. The rheological properties indicated the polymer still had viscous behavior even when high amount of filler was added. The storage and loss modulus of the composites enhanced with filler fraction, the PLA composites with 30 and 40% content, however, exhibited very high values probably due to filler aggregates and low filler‐polymer interfacial interactions. The filler particles were observed to be uniformly distributed in the polymer matrices, though some filler aggregates were also observed in the composites with higher filler fractions. After embedding in compost soil, the composites had significantly enhanced extent of biodegradation as compared to pure polymers, thus, confirming the “true” biocomposite nature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40816.     

Processing of porous carbon with tunable pore structure by the carbide-derived carbon method

Biomorphic TiC ceramics were covered with highly porous carbon, so-called carbide-derived carbon (CDC), by selective etching of Ti with chlorine in a temperature range between 400° C and 1,200°C. Microporous carbon with narrow pore size distribution was obtained at temperature ranging from 400°C to 800°C. Chlorination at higher temperatures leads to formation of mesopores because of increased degree of order of the obtained CDC. A higher etching rate as well as higher degree of order at lower reaction temperature was observed if a catalytically active metal like Fe or Ru was presented during the chlorination process. This is associated with an increased amount of mesopores and with a decrease in specific surface area. Therefore, the CDC processing in the presence of a catalyst offers another way to produce ordered carbon structures at lower temperatures.     

Resonance in a granular system

The dynamics of a 3D vibrated granular system is investigated. A new effect of resonant behaviour in the granular system is reported. The resonant frequencies can cause vibro-induced segregation in a granular system.     

Composite inorganic membranes containing nanoparticles of hydrated zirconium dioxide for electrodialytic separation

The aim of the work was to elucidate the nature of charge-selective properties of macroporous composite inorganic membranes modified with nanoparticles of hydrated zirconium dioxide. The membranes have been investigated using methods of standard contact porosimetry, potentiometry, electron microscopy and small-angle X-ray scattering. The ion exchanger has been found to deposit inside pores of ceramics. Differential curves of pore volume distribution have been resolved using Lorentz functions; each maximum has been related to structure elements of the matrix and ion exchanger by means of calculations according to homogeneous and heterogeneous geometrical models. It was found that the voids, the radius of which is 4 to 8 nm, are responsible for charge selectivity of the composite membranes. These pores are formed due to blocking of macropores of ceramics with aggregates of nanoparticles of the ion exchanger; the radius of these aggregates is 20 to 24 nm. The membranes were applied to desalination of the solution containing NaCl. The removal degree of the salt from the solution reached 95% and 9% for the composite and unmodified membranes, respectively.     

Li collection experiments on T-11M and T-10 in framework of Li closed loop concept

The concept of a steady state tokamak with plasma facing components (PFC) on the basis of liquid lithium circulation demands the decision of three tasks: lithium injection to the plasma, lithium ions collection before their deposition on the vacuum vessel and lithium returning to the injection zone. Main subject of paper is the investigations of Li collection by different types of limiters intersected the scrape-of-layer (SOL) in T-10 and T-11M tokamaks. For finding solution for this problem in T-11M and T-10, experiments have been applied with Li-, C-rail limiters and ring SS R-limiter-collector (T-11M). The efficiency of Li collection by limiters in T-11M and T-10 tokamaks was investigated by post mortem sample–witness analysis and (T-11M) by the use of the mobile graphite probe (limiter) as a recombination target in the stream of lithium ions. The characteristic depth of lithium penetration in the SOL area of T-11M is about 2 cm and 4 cm in SOL of T-10. The quantitative analysis of the sample–witnesses located on T-11M limiters showed that 60 ± 20% of the lithium injected during plasma operating of T-11M had been collected by limiters. It confirms an opportunity of the lithium ions collection by limiters in tokamak SOL.     

Silica‐Based,Organically Modified Host Material for Waveguide Structuring by Two‐Photon‐Induced Photopolymerization

The three‐dimensional fabrication of optical waveguides has gained increasing interest in recent years to establish interconnections between electrical components on a very small scale where copper circuits encounter severe limitations. In this work the application of optically clear, organically modified porous silica monoliths and thin films as a host material for polymeric waveguides to be inscribed into the solid host structure by two‐photon‐induced photopolymerization is investigated. Porosity is generated using a lyotropic liquid crystalline surfactant/solvent system as a template for the solid silica material obtained by a sol–gel transition of a liquid precursor. In order to reduce the brittleness of the purely inorganic material, organic–inorganic co‐precursor molecules that contain poly(ethylene glycol) chains are synthesized and added to the mixture, which successfully suppresses macroscopic cracking and leads to flexible thin films. The structure of the thus‐obtained porous organic–inorganic hybrid material is investigated by atomic force microscopy. It is shown that the modified material is suitable for infiltration with photocurable monomers and functional polymeric waveguides can be inscribed by selective two‐photon‐induced photopolymerization.     

Frequency mixing application based on BaTiO3 ceramic: Design and functional characterization

In the present article, we propose a ferroelectric‐based frequency mixer capable of reconfigurable functioning, a key trait in multi frequency band coverage, based on the nonlinear dielectric properties of BaSn_xTi_1?xO₃ ceramics. According to the properties of BaSn_xTi_1?xO₃ solid solutions, an optimum composition was selected to demonstrate the applicability as a discrete passive mixer with a simple coplanar geometry. A prototype device, with four coplanar capacitors, connected in a circular electric circuit was built on the surface of the selected ceramic. In this configuration, mixing products of the pumping and working signals were obtained and characterized.