Hydroxyl end-functionalized poly(2-isopropyl oxazoline)s used as nano-sized colloidal templates for preparation of hollow polymeric nanocapsules

Hollow polymeric nanocapsules with a thermosensitive membrane are prepared and characterized. They reversibly change their dimensions during temperature variations below and above the transition of the membrane. The nanocapsules were prepared by three steps: (i) well-defined mesoglobules prepared from an LCST polymer (hydroxyl end functionalized poly(2-isopropyl-2-oxazoline), PiPOZ-OH) were coated with a thermo-sensitive cross-linked shell formed via seeded radical copolymerization of N-isopropylacrylamide (NIPAM) and N,N′-bis-methylene acrylamide to produce core–shell nanoparticles (ii), which were subjected to extensive dialysis below the LCSTs of both the core-forming PiPOZ-OH and shell-forming PNIPAM to remove the core (iii). The use of a core-forming polymer of low molecular weight (<8900 g mol⁻¹), narrow dispersity (<1.15) and relatively low T_g (52–68 °C) is beneficial as far as the effectiveness of the removal of the cores is concerned. The inherent immiscibility between PiPOZ-OH and PNIPAM as well as the specific raspberry-like structure of the core–shell particles also contributed for enhancement of the core removal effectiveness.     

The bending of silicon wafers by thin polycrystalline silicon film deposition and by film doping using boron diffusion

The existence of stress at the interface between a monocrystalline silicon substrate and a thin (under 1 μm) polycrystalline silicon film was demonstrated using X-ray topography. The wafer-bending direction was studied for a polycrystalline film doped by boron prediffusion and by prediffusion followed by drive-in diffusion. Wafer bending in the presence of SiO₂ thermal growth between the monocrystalline substrate and the polycrystalline film was also investigated. The causes of the wafer bending and its change during polycrystalline film doping are discussed.     

Über die Aufkohlungskinetik von Eisen-Zink-Legierungen

Untersuchung der Aufkohlungskinetik von zwischen 870 und 1107 °C ferritischen und austenitischen Eisen-Zink-Legierungen. Mikrohärtemessungen und Untersuchungen der Kohlenstoffverteilung innerhalb der Aufkohlungsschicht mit der Röntgenmikrosonde. Ermittlung der Wachstumskinetik der Schicht und Erörterung der Ergebnisse im Zusammenhang mit der Diffusion des Kohlenstoffs in den Legierungen.     

Electrospun polylactide‐based materials for curcumin release: Photostability,antimicrobial activity,and anticoagulant effect

New microfibrous materials from polylactide and polyvinylpyrrolidone or polyethylene glycol loaded with the natural polyphenolic compound curcumin have been prepared by one‐pot electrospinning. The incorporation of curcumin in the fibers contributes to shielding curcumin from photodestruction and to enhancement of the mechanical properties of the fibers. Moreover, the formation of hydrogen bonds between curcumin and polyvinylpyrrolidone or polyethylene glycol facilitates the drug release. Curcumin release provides for the antibacterial and anticoagulant activity of the curcumin‐loaded mats and prevents adhesion and aggregation of platelets onto the surface of the mats. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42940.     

Materials from Nanosized ZnO and Polyacrylonitrile: Properties Depending on the Design of Fibers (Electrospinning or Electrospinning/Electrospraying)

New hybrid fibrous materials from polyacrylonitrile (PAN) and nanosized zinc oxide have been prepared by electrospinning or by combining electrospinning and electrospraying techniques. Electrospinning of PAN/nanosized zinc oxide dispersion leads to the production of mats with nanofiller distributed mainly in the bulk of the fibers. Electrospinning of PAN solution performed in conjunction with electrospraying of nanosized zinc oxide dispersion enables the preparation of fibers decorated with zinc oxide particles. The incorporation of zinc oxide in the fibers leads to enhancement of the mechanical properties of the mats. The fibrous materials having zinc oxide particles situated on the fibers surface exhibit better photocatalytic activity in respect to photo-induced degradation of the model dye methylene blue and greater antibacterial activity against the pathogenic microorganism Staphylococcus aureus.     

Bilateral tubo-ovarian actinomycosis and rheumatoid arthritis

It's a lot cheaper to develop a compliance plan than fight fraud charges. Trouble is, off-the-shelf wisdom is hard to come by. Here's sage advice from compliance pros on how to put your plan in motion.     

Association between polyether–polyamine block-copolymers and low molecular weight polyacids in solution

An ABA block-copolymer in which A is a poly(N-tert-butylimino-ethylene) segment and B a poly(oxytetramethylene) segment has been prepared. The salt form of this polymer, obtained with low molecular weight polycarboxylic acids such as citric acid or benzene-1,3,5-tricarboxylic acid, was found to form ionic networks in organic solvents of low or medium polarity, when the concentration of the polymeric salt exceeded a critical concentration, between 2 and 4wt%. The viscosities of the polymeric salt solutions were strongly pseudoplastic, showing a yield point and thixotropic behaviour.     

Exergy analysis of processes of natural gas conversion and mazut gasification

Thermodynamic investigations using exergy on processes of catalytic high-temperature conversion of natural gas with water (I), high-temperature conversion of natural gas with oxygen (II), and mazut steam-oxygen gasification (III) have been carried out for the purpose of finding an energy optimization criterion for chemical systems that is unaffected by side effects, initial raw materials, and end products. Of the processes investigated, process II has beem found to have the highest thermodynamic efficiency. The conversion of fuel gas was more efficient than mazut gasification. Our results may be used for technical and economic evaluations of the processes.     

Kinetic investigation and regularities during the synthesis of Poly(ε-caprolactam-co-ε-caprolactone) and Poly(ε-caprolactam-co-δ-valerolactone) biodegradable copolymers

Summary Large diversity of tailor-made poly[(ε-caprolactam)-co-(ε-caprolactone)] P[(CLA)-co-(CLO)] and poly[(ε-caprolactam)-co-(δ-valerolactone)] P[(CLA)-co-(VLO)] copolymers have been obtained via activated anionic polymerization of ε-caprolactam (CLA) with sodium caprolactam (NaCL) as a basic initiator. In the present study several poly(ε-caprolactones) (PCLOs) and poly(δ-valerolactone) polyols were employed as effective bifunctional polymeric activators (PACs) and suitable comonomers of CLA. The obtained poly(esteramides) PEAS were isolated and their structure was confirmed by the ¹H NMR and FTIR spectroscopy. The influence of the molecular weight and type of the PACs, the CLA/PAC ratio and polymerization conditions on the conversion, intrinsic viscosity and polymerization kinetic was explored. The results demonstrated that the use of the PACs reduces the polymerization time to several minutes and polymerization process proceeds without induction period at low energy of activation and high yield of copolymers. Evaluation of the PACs activity and the activation energy confirmed that the PACs are highly active compounds efficient to CLA features modification.