Preparation of Breathable Cellulose Based Polymeric Membranes with Enhanced Water Resistance for the Building Industry

This study focuses on the development of advanced water-resistant bio-based membranes with enhanced vapour permeability for use within building envelopes. Building walls are vulnerable to moisture damage and mold growth due to water penetration, built-in moisture, and interstitial condensation. In this work, breathable composite membranes were prepared using micro-fibrillated cellulose fiber (CF) and polylactic acid (PLA). The chemical composition and physical structure of CF is responsible for its hydrophilic nature, which affects its compatibility with polymers and consequently its performance in the presence of excessive moisture conditions. To enhance the dispersibility of CF in the PLA polymer, the fibers were treated with an organic phosphoric acid ester-based surfactant. The hygroscopic properties of the PLA-CF composites were improved after surfactant treatment and the membranes were resistant to water yet permeable to vapor. Morphological examination of the surface showed better interfacial adhesion and enhanced dispersion of CF in the PLA matrix. Thermal analysis revealed that the surfactant treatment of CF enhanced the glass transition temperature and thermal stability of the composite samples. These bio-based membranes have immense potential as durable, eco-friendly, weather resistant barriers for the building industry as they can adapt to varying humidity conditions, thus allowing entrapped water vapor to pass through and escape the building, eventually prolonging the building life.

Metabolism of phosphorus compoundsand taxonomic position of the Aspergillus niger AM1 mold

White phosphorus is one of the most dangerous environmental pollutants. However, it is used in industry and for military purposes; therefore, it is impossible to overlook the fact that this substance is constantly released into the environment. In our works, cultures of microorganisms growing in media with a content of white phosphorus up to 1% were obtained for the first time. This exceeds the TLV in wastewater by 5000 times! These cultures are unique, and they are only in our possession. For the first time, cultures were grown in media containing white phosphorus as the sole source of phosphorus. In these environments, microorganisms grew without experiencing phosphorus starvation. That is, they oxidized white phosphorus to phosphate, which is necessary for vital activity! This is first ever example of the inclusion of white phosphorus in the biospheric circulation of the phosphorus element. It turned out that microorganisms that neutralize elemental phosphorus are able to biodegrade most of the spectrum of phosphorus compounds. Our studies of the metabolism of phosphorus-containing compounds of various classes confirm this. Since the chemistry of phosphorus is diverse, it is necessary to collect significant material on the metabolism of many classes of compounds. In this article, we describe the continuation of this work. It turned out that Aspergillus niger AM1 is able to utilize dithiophosphate of the simplest structure as sources of phosphorus, but is not able to utilize substituted dithiophosphonate. In addition, in the present work, we clarified the previously obtained results on the metabolism of phosphoric acid ester and phosphoramide.The NMR method demonstrated that A. niger AM1 slowly metabolizes hypophosphite resulting from the biodegradation of white phosphorus, but does not metabolize phosphite. The NMR data conforms to fungal growth dynamics with these substances in media. Also, was first studied phylogenetic relationship of A. niger AM1 with biodegradable A. niger and A. bombycis strains from the NCBI database.