University of Szczecin

Abstract: This paper reviews the state of the art in the field of chemical recycling of poly(ethylene terephthalate) (PET). Advantages of the chemical recycling of PET, the theoretical basis of the ester bond cleavage, and a wide spectrum of degrading agents and final products are presented. Chemical processes applied in polymer recycling are divided into six groups: methanolysis, glycolysis, hydrolysis, ammonolysis, aminolysis, and other methods. Numerous possibilities for the utilization of waste PET as a very useful raw chemical material are described on the basis of literature. A comparison of chemical recycling methods is carried out. The following aspects were taken into consideration: (i) flexibility in utilizing a variety of waste types, (ii) conditions necessary for degradation including safety requirements, (iii) economic aspects, and (iv) product versatility. A total of 108 references including 46 patents are cited in this paper.

Abstract: The influence of treatment with ammonia on adsorption properties toward CO2 was examined for commercially available CWZ-35 activated carbon. The treatment was performed for 2 h at elevated temperatures ranging from 200 to 1000 °C. The surface groups were determined by Fourier transform infrared (FTIR) spectroscopy of solid. Additionally FTIR measurement was done for outlet gases evolved during temperature-programmed desorption from the ammonia-treated activated carbon. FTIR spectra of solid samples confirmed the presence of N-containing groups in ammonia-treated carbon. Adsorption properties against CO2 were checked for both pristine and ammonia-treated activated carbons using thermogravimetric analysis. Activated carbon treated with ammonia demonstrated distinct enhancement in adsorption of CO2.

Abstract: TiO 2 -mounted activated carbon was prepared through hydrolytic precipitation of TiO 2 from teraisopropyl orthotitanate and following heat treatment at 650–900 °C for 1 h under a flow of nitrogen The removal of phenol from its aqueous solution under UV irradiation was measured on TiO 2 -mounted activated carbons thus prepared Although BET surface area of TiO 2 -mounted activated carbons decreased drastically in comparison with the original activated carbon, the efficiency of phenol removal under UV irradiation was high The sample heated at 900 °C, which consisted mainly of rutile phase, showed the highest total removal of phenol Efficiency of phenol degradation is reduced because of phenol adsorption on the catalyst

Abstract: Despite its continued observational successes, there is a persistent (and growing) interest in extending cosmology beyond the standard model, ΛCDM. This is motivated by a range of apparently serious theoretical issues, involving such questions as the cosmological constant problem, the particle nature of dark matter, the validity of general relativity on large scales, the existence of anomalies in the CMB and on small scales, and the predictivity and testability of the inflationary paradigm. In this paper, we summarize the current status of ΛCDM as a physical theory, and review investigations into possible alternatives along a number of different lines, with a particular focus on highlighting the most promising directions. While the fundamental problems are proving reluctant to yield, the study of alternative cosmologies has led to considerable progress, with much more to come if hopes about forthcoming high-precision observations and new theoretical ideas are fulfilled.

Abstract: Solvent-free, supersoft and superelastic polymer melts and networks made from bottlebrush macromolecules can display low modulus, high strain at break, and extraordinary elasticity. Polymer gels are the only viable class of synthetic materials with a Young’s modulus below 100 kPa conforming to biological applications1,2,3, yet those gel properties require a solvent fraction4,5,6,7. The presence of a solvent can lead to phase separation, evaporation and leakage on deformation, diminishing gel elasticity and eliciting inflammatory responses in any surrounding tissues. Here, we report solvent-free, supersoft and superelastic polymer melts and networks prepared from bottlebrush macromolecules. The brush-like architecture expands the diameter of the polymer chains, diluting their entanglements without markedly increasing stiffness. This adjustable interplay between chain diameter and stiffness makes it possible to tailor the network’s elastic modulus and extensibility without the complications associated with a swollen gel. The bottlebrush melts and elastomers exhibit an unprecedented combination of low modulus (∼100 Pa), high strain at break (∼1,000%), and extraordinary elasticity, properties that are on par with those of designer gels8,9.