Gamma-Irradiated Gelatin-Based Films Modified by HEMA for Medical Application

The present article describes the synthesis and characterization of bi-component polymer systems based on gelatin films incorporated with 2-hydroxyethyl methacrylate (HEMA) monomer, developed for medical application. Gelatin films were prepared by the addition of HEMA of different concentrations (0–30 wt.%) and irradiated with various radiation doses (0–5 kGy). Tensile strength and tear strength of the irradiated gelatin films were found to increase with increasing HEMA up to 20 wt.% as well as radiation doses (1 kGy) as optimized. The maximum tensile and tear strengths of irradiated gelatin films with HEMA were found to be 79.1 MPa and 83.2 N/mm, respectively, at the optimum conditions, and these values were about double that of a reference film prepared without additives. In addition, morphological analysis was done by scanning electron microscopy (SEM) and showed how HEMA cemented and was covered with gelatin in the blend. Thermomechanical analysis was carried out to investigate the shifting of glass transition temperature (T_g) towards higher temperature due to HEMA addition, and the effect of this film was tested on the human body in order to determine whether it can be applied for medical purposes.     

The development of radioactive glass surrogates for fallout debris

The production of glass that emulates fallout is desired by the nuclear forensics community for training and measurement exercises. The composition of nuclear fallout is complex, with widely varying isotopic compositions (Fahey et al., Proc Natl Acad Sci USA 107(47):20207–20212, 2010; Bellucci et al., Anal Chem 85:7588–7593, 2013; Wallace et al., J Radioanal Nucl Chem, 2013; Belloni et al., J Environ Radioact 102:852–862, 2011; Freiling, Science 139:1058–1059, 1963; Science 133:1991–1999, 1961; Bunney and Sam Government Report: Naval Ordinance Laboratory, White Oak, 1971). As the gaseous cloud traverses from hotter to cooler regions of the atmosphere, the processes of condensation and nucleation entrain environmental materials, vaporized nuclear materials and fission products. The elemental and isotopic composition of the fission products is altered due to chemical fractionation (i.e. the fission product composition that would be expected from fission of the original nuclear material is altered by differences in condensation rates of the elements); the fallout may be enriched or depleted in volatile or refractory fission products. This paper describes preliminary work to synthesize, irradiate and fractionate the fission product content of irradiated particulate glass using a thermal distillation 2 h after irradiation. The glass was synthesized using a solution-based polymerization of tetraethyl orthosilicate. (Izrael, Radioactive fallout after nuclear explosions and accidents, 2002) Uranium was incorporated into the glass particulate at trace concentrations during polymerization. The particulate was subjected to a short thermal neutron irradiation then heated to 1,273 K approximately 2 h after the end of irradiation. Fission products of ^{133, 134, 135}I, ^{132, 134}Te, ¹³⁵Xe, ¹³⁸Cs and ^{91, 92}Sr were observed to be distilled from the particulate. The results of these preliminary studies are discussed.     

Ultrasound-Enhanced Recovery of Butanol/ABE by Pervaporation

The search for renewable sources of energy has led to renewed interests on the biochemical route for the production of butanol. Butanol production suffers from several drawbacks, mainly caused by butanol inhibition to the butanol-producing microorganism which makes it economically uncompetitive against the chemical process. One possible solution proposed is the in situ recovery of acetone–butanol–ethanol (ABE). Among the in situ recovery options, membrane processes like pervaporation have a great potential. Thus, the effects of temperature, feed concentration, and ultrasound irradiation on permeate concentration and permeation flux for the recovery of butanol/ABE by pervaporation from aqueous solutions were investigated in this study. In the butanol–water system, permeate butanol concentration as well as flux increased with an increase in temperature and butanol feed concentration. When pervaporation studies with ABE–water mixture were carried out at 60 °C for 2, 4, 8, 16, and 24 h, pervaporation profile revealed an optimal permeate concentration as well as permeation flux. Applications of ultrasound irradiation on pervaporation improved permeate concentration by about 23 g/L for both butanol and ABE. Ultrasound irradiation also improved butanol and ABE mass permeation flux by about 13 and 11 %, respectively.     

Atomgewicht des Nickels

Ohne Zusammenfassung     

Solvent-induced crystallization. I. Crystallization kinetics

The kinetics of crystallization of quenched poly(ethylene terephthalate) (PET) films during the imbibition of methylene chloride (MeCl₂) vapor is studied by density measurements. The effects of film thickness (0.0025–0.086 cm) and temperature (0–38°C) were examined. The data suggest that MeCl₂ transport controls the crystallization in thick films and at elevated temperatures, but that spherulite growth controls in thin films and at reduced temperatures. The application of a mathematical model developed previously supports this mechanistic interpretation of the data.     

Local acid environment in poly(ethylene‐ran‐methacrylic acid) ionomers

The local environment of unneutralized carboxylic acid groups in poly(ethylene‐ran‐methacrylic acid) (E/MAA) ionomers neutralized with monovalent (Li and Na) and divalent (Ca and Zn) ions has been investigated with Fourier transform infrared spectroscopy. These unneutralized acid groups interact with one another to form acid dimers, and they associate with existing neutralized complexes. At room temperature, no free acids can be detected for any system, not even for pure E/MAA. With the acid dimer peak (1700 cm^?1) and a known unneutralized acid concentration, the concentration of acids associated with a neutralized complex can be determined. This concentration of associated acids increases with increasing neutralization, reaches a maximum below 50% neutralization, and then decreases toward zero near 80% neutralization. This behavior is perhaps due to the increased driving force for aggregation of the neutralization acids. Although Li, Na, and Ca contain similar concentrations of associated acids over the range of neutralizations, the Zn system contains far fewer associated acids (i.e., more acid dimers) at any particular neutralization level. These results are confirmed by an analysis of the absorbance in the neutralized region (1650–1500 cm^?1). © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2833–2841, 2002     

Benzolactams. II. Synthesis of tetrahydrobenz[d]indeno-[1,2-b]azepines and their 12-Oxo derivatives

Aromatic methoxy and/or methylenedioxy substituted 7-methyltetrahydrobenz[d]indeno[1,2-b]-azepines 7 and their 12-oxo derivatives 8 were efficiently synthesized by the general method consisting of two types of intramolecular dehydrative cyclizations, as follows. N-Methyl-N-β-phenethylacetamides 1 were cyanomethylated in the two-step process of chloromethylation and treatment of the resultant benzyl chlorides with sodium cyanide. The condensation of the benzyl cyanides 2 with the appropriate benzaldehydes, followed by reduction of the benzylidene function, gave α,β-diphenylpropionitriles 3 . Successively, hydrolysis to the amino acids 4 and the thermal cyclization converted 3 to the benzylbenzazepinones 5 , which were also prepared by benzylation of the benzazepinones 6 smoothly by heating of 5 with phosphoryl chloride to afford the title azepines 7 . Further, these tetracyclic enamines 7 underwent autoxidation to the corresponding 12-oxo derivatives 8 , on exposure to oxygen in the presence of Triton B.