Industrial & Engineering Chemistry Research最新文献

Atomistic configurations of model poly(phenylsulfone) (PPSU) systems, with molecular lengths ranging from N = 5 to N = 50 monomers, were thoroughly relaxed by subjecting them to detailed molecular dynamics (MD) simulations. We present results for their thermal properties, including the thermal expansion coefficient (a_P) and the thermal conductivity (λ). Our simulation predictions for both properties align relatively closely with experimental values, and no significant correlation with the PPSU chain length was recorded. Prior to examining the thermal properties at T = 300 K, we conducted an extensive analysis of the thermodynamic, structural, conformational, and dynamic properties of these models in the molten state at T = 700 K. This provided valuable microscopic insights, such as the dependence of the mean-squared radius of gyration, mean-squared end-to-end distance, self-diffusion coefficient, and total relaxation time on molecular weight, which were subsequently correlated with the zero-rate shear viscosity. During the quenching process from high temperatures to ambient conditions, we estimated the glass transition temperature (T_g) of all model systems, and the predicted values relatively matched the experimental data within the expected range, considering the high cooling rates in the MD simulations. Our simulations effectively captured the important dependence of T_g on molecular weight.

Mass transfer is critical in liquid–liquid biphasic catalysis, with considerable attention focused on enhancing mass transfer primarily through increasing the interfacial area. However, the driving force, determined by the concentration gradient, has received far less attention. In this work, we introduce an alternative approach that not only maximizes the interfacial area and minimizes the mass transfer distance but also enhances the driving force through molecular interactions between amphiphilic polymers and substrates, resulting in an enhanced mass transfer process. Specifically, an amphiphilic polymer was synthesized with a positively charged hydrophilic segment and a hydrophobic segment containing a pyridine motif. The pyridine motif facilitates the attraction of chlorobenzene and dichloromethane to the water-organic interface, creating a concentration gradient that boosts the driving force. Meanwhile, negatively charged bacteria are drawn to the interface through electrostatic interactions, further reducing the mass transfer distance. As a result, the degradation of chlorobenzene and dichloromethane was improved utmost 3- and 5-fold than their controls, respectively. Considering the diverse forms of molecular interactions, this work demonstrates the concept of enhancing the driving force to intensify mass transfer processes, offering promising avenues for improving reaction efficiency in advanced biosynthesis.

Anion exchange membrane water electrolyzer (AEMWE) is an emerging technology for large-scale hydrogen production, where membrane electrode assembly (MEA) plays a critical role in the electrolyzer efficiency. This study investigates the effects of different membranes (Piperion, Aemion, and Sustainion) and gaskets (Viton, poly(tetrafluoroethylene) (PTFE), and Silicon) using a non-platinum group metal (non-PGM) bifunctional electrocatalyst under fixed compression and flow rates. Membrane properties such as ionic resistance and diffusion and gasket properties like thermal suitability and compressibility significantly affect the overall performance of AEMWE. The results indicate that Sustainion and Aemion membranes are best suited for lab-scale and industrial applications, respectively, while Silicon and PTFE gaskets are optimal for corresponding scales. Understanding these effects can help to improve the efficiency and guide material selection. This study provides valuable insights for researchers developing AEMWE technology, enabling advancements from laboratory research to megawatt-level industrial hydrogen production and supporting the transition to clean-energy solutions.