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Abstract Plastic transformations are critical to ongoing recycling and upcycling efforts, but the complexity of the reactions makes it difficult to understand the effect of individual factors on reaction rates and product distributions experimentally. In this work, we report on a multiscale simulation framework for studying polymer transformations that incorporates affordable high‐level coupled cluster calculations combined with benchmarked density functional theory calculations, detailed conformer search, and lattice‐based kinetic Monte Carlo simulations to provide the temporal and spatial evolution of the polymer during transformations. Our framework can match experimentally observed reaction times within an order of magnitudewithoutany parameter estimation in base‐assisted dehydrochlorination of polyvinyl chloride. We determine that the E2 reaction mechanism dominates the reaction and demonstrate that different structural defects can inhibit or promote directional polyene growth as well as affect the structure of the dehydrochlorination product. 

Abstract Conversion of epichlorohydrin to glycidyl ethers creates versatile precursors that can be transformed into a variety of molecular species with glycerol skeletons, enabling the design of molecules with highly tailored functionalities. The synthesis of 2,2,2‐trifluoroethyl glycidyl ether (TFGE, IUPAC name: 2‐[(2,2,2‐trifluoroethoxy)methyl]oxirane, CAS# 1535‐91‐7) was optimized to provide high yield/selectivity and good “green metrics.” TFGE was then used as a platform molecule in the synthesis of asymmetric glycerol 1,3‐diether‐2‐alcohol derivatives, which were subsequently transformed to 1,2,3‐triethers or 1,3‐diether‐2‐ketones. The density, viscosity, and CO₂solubility of each molecule were measured and compared with those of other glycerol‐derived compounds as well as compounds with similar functional groups. Furthermore, quantum chemical calculations were performed to understand the structure–property–performance relationships of these molecules for CO₂absorption. Based on the results in this work, we foresee that TFGE (and similar glycidyl ethers) would offer great flexibility in molecular design of green solvents and precursors to more complex compounds. 

Plastic is ubiquitous across all aspects of modern life. Despite its usefulness, only 9% of all plastic waste ever produced has been recycled, leaving a tremendous amount that ends up in landfills and the environment. New strategies need to investigate using this waste plastic. This report analyzes upcycling waste plastics into membranes for water and gas separations. Polyethylene terephthalate, polystyrene, poly(vinyl chloride), polyethylene, polypropylene, and tire rubber have been studied for use as membranes. Future work needs to investigate greener solvents, health and safety aspects, costs, supply and demand, and life cycle assessments for upcycling plastic waste into membranes. 

In this study, a three-dimensional off-lattice kinetic Monte Carlo-Molecular Dynamics (KMC-MD) simulation framework [Comp. Mat. Sci. 229, 112421 (2023)] is used to investigate the dehydrochlorination/conjugation transformation of polyvinyl chloride (PVC) in sodium hydroxide (NaOH) with atomistic resolutions at experimental timescales (103 – 106 s). Our framework enables an examination of the competing reaction pathways and molecular-scale changes influenced by various solvents (acetone, ethylene glycol, triethylene glycol, tetrahydrofuran, and bio-derived solvents), as well as the influence of varying molecular weight distributions, NaOH concentrations, and temperatures. The algorithm simulates bond cleavage and formation during the KMC stages, whereas the MD stage is dedicated to the relaxation and thermalization of the PVC-NaOH-solvent system. The framework allows us to capture important configurational aspects (mixing, correlations, clustering, etc.) that are not accessible with a traditional microkinetic model, and it potentially allows us to perform benchmarking at experimental timescales. 

Quantum tunnelling drives chloride leaching from polyvinyl chloride to water offering new insights into plastic degradation and transformation processes. 

In our prior study [Olowookere, F. V.; Turner, C. H. J. Phys. Chem. B 2023, 127(42), 9144–9154], we introduced a new scaling relationship to predict gas solute diffusion at challenging conditions, focusing on CO2 and SO2 diffusion in multivalent ionic liquid (IL) solvents. This work extends our initial exploratory study into a much broader array of systems, encompassing additional solutes (N2, CH4, C2H6, C3H8, C3H8O, and H2O) and a variety of different ionic liquid species ([Bzmim3]3+, [Bzmim4]4+, [BMIM]+, [EMIM]+, [HMIM]+, [NapO2]2–, [BzO3]3–, [BF4]−, [Tf2N]−, and [PF6]−). Our study demonstrates a remarkably robust logarithmic correlation between solute diffusion and solvent accessible surface area (SA) across 20 different additional systems. We perform comprehensive analyses of the underlying molecular phenomena responsible for this correlation, including solute lifetime distributions, void space dynamics, and Voronoi tessellation, in order to elucidate a stronger mechanistic understanding of this behavior. Our findings highlight a direct link between the solvent accessible SA and the size of the void domains. Overall, our scaling approach provides an efficient and reliable approach for predicting diffusion from analyses of short simulations at higher temperatures. 

Thin-film-composite (TFC) nanofiltration membranes represent the pinnacle of membrane technology in water treatment and desalination. These membranes typically consist of a polyamide (PA) selective layer and a membrane support layer, often constructed from commercially available materials like polyethersulfone (PES). However, there exists an alternative approach that involves the use of different polymers, preferably upcycled waste polymers, as a viable support layer for TFC membranes. Successfully implementing the upcycling of waste plastics into high-value support membranes can make a significant contribution to addressing the issue of plastic waste pollution. One of the primary challenges associated with utilizing upcycled polymers as support layers is the potential impact on the polyamide selective layer of TFC membranes, subsequently affecting their performance in terms of permeability, rejection, and antifouling properties. In this study, we demonstrate the successful fabrication of TFC membranes with a support layer crafted from upcycled waste PVC pipe. We conducted a comprehensive investigation into the effects of upcycled PVC on the structural and physicochemical properties of the polyamide layer. The ultrafiltration (UF) support membranes were fabricated from waste PVC pipe via the nonsolvent induced phase separation (NIPS) method. Subsequently, a polyamide layer was synthesized atop the Upcycled PVC membrane using interfacial polymerization (IP). The physicochemical properties and performance of the TFC membranes with upcycled PVC support layer were compared with membranes with research-grade (RG) PVC and commercial PES support layers. The results unveiled that the TFC membrane with upcycled PVC support layer exhibited higher water permeability (18.2 LMH/bar), in contrast to RG TFC (15.5 LMH/bar) and PES TFC membranes (13.7 LMH/bar). Furthermore, the salt rejection capabilities of the upcycled PVC TFC membrane were competitive and well within an acceptable range.