Compositional analysis of multilayered plastic constituents and constituent mixtures using benchtop H NMR spectroscopy.

Multilayered plastics are widely used in food packaging and other commercial applications due to their tailored functional properties. By layering different polymers, the multilayered composite material can have enhanced mechanical, thermal, and barrier properties compared to a single plastic. However, there is a significant need to recycle these multilayer plastics, but their complex structure offers significant challenges to their successful recycling.

Development of Structure-Property Relationships for Ammonium Transport through Charged Organogels.

Ammonia is a promising carbon-free fuel, but current methods to produce ammonia are energy intensive. New methods are thereby needed, with one promising method being electrochemical nitrogen reduction cells. Efficient cell operation requires robust catalysts but also efficient membrane separators that permit the selective transport of ions while minimizing the transport of the products across the cell.

Salt Transport in Crosslinked Hydrogel Membranes Containing Zwitterionic Sulfobetaine Methacrylate and Hydrophobic Phenyl Acrylate.

Produced water is a by-product of industrial operations, such as hydraulic fracturing for increased oil recovery, that causes environmental issues since it includes different metal ions (e.g., Li, K, Ni, Mg, etc.

Controlling Fractional Free Volume, Transport, and Co-Transport of Alcohols and Carboxylate Salts in PEGDA Membranes.

Understanding multi-component transport through polymer membranes is critical for separation applications such as water purification, energy devices, etc. Specifically for CO reduction cells, where the CO reduction products (alcohols and carboxylate salts), crossover of these species is undesirable and improving the design of ion exchange membranes to prevent this behavior is needed. Previously, it was observed that acetate transport increased in copermeation with alcohols for cation exchange membranes consisting of poly(ethylene glycol) diacrylate (PEGDA) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and that the inclusion of poly(ethylene glycol) methacrylate (PEGMA) ( = 5, represents the number of ethylene oxide repeat units) could suppress this behavior.

Theoretical and Experimental Considerations for Investigating Multicomponent Diffusion in Hydrated, Dense Polymer Membranes.

In many applications of hydrated, dense polymer membranes-including fuel cells, desalination, molecular separations, electrolyzers, and solar fuels devices-the membrane is challenged with aqueous streams that contain multiple solutes. The presence of multiple solutes presents a complex process because each solute can have different interactions with the polymer membrane and with other solutes, which collectively determine the transport behavior and separation performance that is observed. It is critical to understand the theoretical framework behind and experimental considerations for understanding how the presence of multiple solutes impacts diffusion, and thereby, the design of membranes.

Transport and Co-Transport of Carboxylate Ions and Ethanol in Anion Exchange Membranes.

Understanding multi-component transport behavior through hydrated dense membranes is of interest for numerous applications. For the particular case of photoelectrochemical CO reduction cells, it is important to understand the multi-component transport behavior of CO electrochemical reduction products including mobile formate, acetate and ethanol in the ion exchange membranes as one role of the membrane in these devices is to minimize the permeation of these products. Anion exchange membranes (AEM) have been employed in these and other electrochemical devices as they act to facilitate the transport of common electrolytes (i.

Low-field H NMR spectroscopy: Factors impacting signal-to-noise ratio and experimental time in the context of mixed microstructure polyisoprenes.

Low-cost, high-accuracy characterization of polymeric materials is critical for satisfying societal demand for high-quality materials with ultra-specific requirements. Low-field nuclear magnetic resonance (NMR) spectroscopy presents an opportunity to replace costlier or destructive methods while utilizing nondeuterated solvents. Many factors play key roles in the ability of low-field NMR spectroscopy to accurately analyze polymer systems.

Low-field H-NMR spectroscopy for compositional analysis of multicomponent polymer systems.

The accurate characterization of relative composition in multicomponent polymer systems such as statistical copolymers, block copolymers, and polymer blends is critical to understanding and predicting their behavior. Typically, polymer compositional analysis is performed using 1H Nuclear Magnetic Resonance (NMR) Spectroscopy which provides quantitative chemical group concentrations without prior calibration. This utility has led 1H NMR spectroscopy to become a routine method for the molecular characterization of polymers.

Formation of a Rigid Amorphous Fraction in Poly(3-(2'-ethyl)hexylthiophene).

Herein, we detail the formation of a rigid amorphous fraction in poly(3-(2'-ethyl)hexylthiophene) (P3EHT) at high relative crystallinity, yielding a more complete picture of the solid-state structure. In the differential scanning calorimetry (DSC) heating scans of isothermally crystallized P3EHT a distinct endothermic peak appears slightly above the crystallization temperature. This previously undescribed endothermic feature of P3EHT's thermal behavior is observed consistently ∼20 °C above the crystallization temperature-shifting to higher temperatures with increasing crystallization temperature-and increases in magnitude with both time and crystallization temperature.