Film-Forming Polymeric Blends Designed for the Removal of Heavy Metals and Radionuclides from Contaminated Surfaces

Surface decontamination is a vast domain. The majority of the methods use a considerable quantity of water, requiring further treatments. This study presents an ecological method for surface decontamination, based on polymeric nanocomposites, specially designed for the removal of heavy metals and radionuclides. Besides being effective in decontaminating the surfaces, these polymeric coatings also reduce the volume of the waste materials. The novelty of this work consists of the innovative path of combining the advantages brought by the film-forming ability of polyvinyl alcohol, with the remarkable metal retention capacity of bentonite nanoclay, together with the chelating ability of alginate, and with one of two ‘new-generation ‘green’ complexing agents’: iminodisuccinic acid (IDS) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). These are used to obtain powerful, customizable, and environmentally friendly, film-forming, water-based solutions, for the surface decontamination of heavy metals or radioactive metals. Decontamination tests revealed a high decontamination efficiency for heavy metals (DF ≈ 95–98%, tested on glass surface) and also for radioactive metals (DF ≈ 91–97% for 241Am, 90Sr-Y and 137Cs, tested on metal, painted metal, plastic, and glass surfaces).This eco-friendly, low-waste, biodegradable method can successfully be employed, alternatively, to classical methods, having comparable capabilities for surface decontamination, but multiple advantages

Strippable Polymeric Nanocomposites Comprising “Green” Chelates, for the Removal of Heavy Metals and Radionuclides

The issue of heavy metal and radionuclide contamination is still causing a great deal of concern worldwide for environmental protection and industrial sites remediation. Various techniques have been developed for surface decontamination aiming for high decontamination factors (DF) and minimal environmental impact, but strippable polymeric nanocomposite coatings are some of the best candidates in this area. In this study, novel strippable coatings for heavy metal and radionuclides decontamination were developed based on the film-forming ability of polyvinyl alcohol, with the remarkable metal retention capacity of bentonite nanoclay, together with the chelating ability of sodium alginate and with “new-generation” “green” complexing agents: iminodisuccinic acid (IDS) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). These environmentally friendly water-based decontamination solutions are capable of generating strippable polymeric films with optimized mechanical and thermal properties while exhibiting high decontamination efficiency (DF ≈ 95–98% for heavy metals tested on glass surface and DF ≈ 91–97% for radionuclides 241Am, 90Sr-Y and 137Cs on metal, painted metal, plastic, and glass surfaces)

Eco–Friendly Peelable Active Nanocomposite Films Designed for Biological and Chemical Warfare Agents Decontamination

In the context of imminent threats concerning biological and chemical warfare agents, the aim of this study was the development of a new method for biological and chemical decontamination, employing non-toxic, film-forming, water-based biodegradable solutions, using a nano sized reagent together with bentonite as trapping agents for the biological and chemical contaminants. Bentonite-supported nanoparticles of Cu, TiO2, and Ag were successfully synthesized and dispersed in a polyvinyl alcohol (PVA)/glycerol (GLY) aqueous solution. The decontamination effectiveness of the proposed solutions was evaluated by qualitative and quantitative analytical techniques on various micro-organisms, with sulfur mustard (HD) and dimethyl methylphosphonate (DMMP) as contaminants. The results indicate that the peelable active nanocomposite films can be successfully used on contaminated surfaces to neutralize and entrap the hazardous materials and their degradation products. Mechanical and thermal characterization of the polymeric films was also performed to validate the decontamination solution’s potential as peelable-film generating materials. The removal efficacy from the contaminated surfaces for the tested micro-organisms varied between 93% and 97%, while for the chemical agent HD, the highest decontamination factor obtained was 90.89%. DMMP was almost completely removed from the contaminated surfaces, and a decontamination factor of 99.97% was obtained

Novel Polyurethanes Based on Recycled Polyethylene Terephthalate: Synthesis, Characterization, and Formulation of Binders for Environmentally Responsible Rocket Propellants

Novel polyurethane-based binders, specifically designed for environmentally responsible rocket propellant composites, were obtained by employing the polyester-polyols that resulted from the degradation of polyethylene terephthalate waste. A new class of “greener” rocket propellants, comprising polyurethanes (based on recycled PET) as the binder, phase stabilized ammonium nitrate (PSAN) as the eco-friendly oxidizer, and triethylene glycol dinitrate (TEGDN) as the energetic plasticizer, together with aluminum as fuel and Fe2O3 as the catalyst, is herein reported. The components of the energetic mixtures were investigated (individually and as composite materials) through specific analytical tools: 1H-NMR, FT-IR, SEM-EDX, DTA and TGA, tensile and compression tests, DMA, and micro-CT. Moreover, the feasibility of this innovative solution is sustained by the ballistic performances exhibited by these composite materials in a subscale rocket motor, proving that these new formulations are suitable for rocket propellant applications