Emily Pentzer

A conceptual map illustrating hybrid CO ₂ -capture composites from solid–liquid synthesis: MOFs, impregnated inorganic sorbents, solvent-impregnated polymers, and liquid-filled microcapsules.

Block copolymers (BCPs) offer distinct advantages for vat photopolymerization by enabling mechanically programmable network structures through microphase‐separated morphologies that can be kinetically trapped during curing, yielding properties unattainable in homogeneous resins. However, the respective roles of repeat‐unit sequence and solvent environment, together with their interplay in directing network formation and mechanical performance, remain unclear. Here, we synthesize a series of CO ₂ ‐based polycarbonate copolymers comprising a crosslinkable glassy poly(vinyl cyclohexene carbonate) (PVCHC, A block) and a non‐crosslinkable soft poly(propylene carbonate) (PPC, B block). The polymer sequence is systematically varied (ABA, BAB, and statistical), and solvent choice controls block‐selective swelling to jointly control gelation behavior, microphase morphology, and mechanical response through changes in the accessibility and local environment of photocrosslinkable vinyl groups during network formation, as revealed by photorheology and small angle x‐ray scattering. By tuning polymer sequence and curing solvent, we transform nominally identical formulations from brittle to highly ductile materials, achieving a three‐orders‐of‐magnitude range in toughness (0.003 to 9.1 MJ m ⁻³ ). These results establish clear structure–processing–property relationships and identify polymer sequence and selective solvation as powerful strategies for programming both printability and performance of block copolymer resins for additive manufacturing.

Block copolymers (BCPs) offer distinct advantages for vat photopolymerization by enabling mechanically programmable network structures through microphase‐separated morphologies that can be kinetically trapped during curing, yielding properties unattainable in homogeneous resins. However, the respective roles of repeat‐unit sequence and solvent environment, together with their interplay in directing network formation and mechanical performance, remain unclear. Here, we synthesize a series of CO ₂ ‐based polycarbonate copolymers comprising a crosslinkable glassy poly(vinyl cyclohexene carbonate) (PVCHC, A block) and a non‐crosslinkable soft poly(propylene carbonate) (PPC, B block). The polymer sequence is systematically varied (ABA, BAB, and statistical), and solvent choice controls block‐selective swelling to jointly control gelation behavior, microphase morphology, and mechanical response through changes in the accessibility and local environment of photocrosslinkable vinyl groups during network formation, as revealed by photorheology and small angle x‐ray scattering. By tuning polymer sequence and curing solvent, we transform nominally identical formulations from brittle to highly ductile materials, achieving a three‐orders‐of‐magnitude range in toughness (0.003 to 9.1 MJ m ⁻³ ). These results establish clear structure–processing–property relationships and identify polymer sequence and selective solvation as powerful strategies for programming both printability and performance of block copolymer resins for additive manufacturing.

Charge and mass transfer are key functionalities of redox-active polymers, impacting applications in energy storage. Tacticity affects polymer chain conformation and mobility, free volume, and redox unit spacing, but the consequences on their ability to store charge remain unclear. Here, we control tacticity in poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PTMA) and demonstrate its decisive influence on electrochemical properties. Isotactic, atactic, and syndiotactic PTMA with mm ∼80%, mr or rm ∼44%, and rr ∼77% configurations, respectively, are synthesized by anionic polymerization. Overall, isotactic PTMA possessed the highest specific capacity and energy -37% higher than syndiotactic PTMA at 5C. Electrochemical analysis of the reaction diffusion and kinetics, as well as electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) analysis of the mass transfer process, reveal that specific capacity and energy are influenced by both processes. Of the three polymers studied, isotactic PTMA exhibited moderate charge transfer kinetics but the least mass transferred in the redox reaction. Meanwhile, atactic PTMA exhibited the fastest kinetics but the most mass transferred. All-atom molecular dynamics (MD) simulations explain this effect, showing that atactic PTMA bears the lowest density and the greatest conformational heterogeneity, leaving greater free volume for solvated ion (de)insertion. This work highlights that tacticity is an important consideration in developing next-generation nonconjugated redox-active polymers for electrochemical energy storage.

Machine learning and high throughput experimentation have heavily influenced the way scientific study is done with demonstrated successes in nearly every field.

We developed microcapsules with PDMS composite shells, showing high CO ₂ direct air capture and regeneration with microwave and radiofrequency.

Transitions between rotationally ordered and disordered states in globular small molecules are associated with large entropy changes and thus hold promise as solid-state barocaloric refrigerants. However, the relationships between elements of the molecular structure and the corresponding thermodynamic properties of the phase transformation between ordered and disordered states remain unresolved. We hypothesize that more spherical molecules, as measured by their rotational moments of inertia, exhibit larger relative increases in their rotational degrees of freedom as they transition to rotationally disordered states. We probe this by isolating the impact of rotational moments of inertia from more dominant factors, including intermolecular bonding, through the selective deuteration of different functional groups of the model plastic crystal molecule neopentyl glycol. We demonstrate a decrease in the phase transition temperature of up to approximately 3 K associated with the existence of deuterated methyl groups and explain this change in terms of relative changes in the rotational moments of inertia of the compounds. This observation places bounds on the role of rotational moments of inertia in thermodynamic aspects of the phase transformation and introduces a vector for subtle modulation of the transition point for cooling applications.

Transitions between rotationally ordered and disordered states in globular small molecules are associated with large entropy changes, and thus, hold promise as solid-state barocaloric refrigerants. However, the relationships between elements of the molecular structure, and the corresponding thermodynamic properties of the phase transformation between ordered and disordered states remain unresolved. We hypothesize that more spherical molecules, as measured by their rotational moments of inertia, exhibit larger relative increases in rotational degrees of freedom as they transition to rotationally disordered states. We probe this by isolating the impact of rotational moments of inertia from more dominant factors, including intermolecular bonding, through selective deuteration of different functional groups of the model plastic crystal molecule neopentyl glycol. We demonstrate a decrease in the phase transition temperature of up to approximately 3 K associated with the existence of deuterated methyl groups and explain this change in terms of relative changes in rotational moments of inertia of the compounds. This observation places bounds on the role of rotational moments of inertia in thermodynamic aspects of the phase transformation, and introduces a vector for subtle tuning of the transition point for cooling applications.

Understanding charge transfer in redox‐active non‐conjugated polymers is key to unlocking their potential as alternative materials for energy storage. Many factors contribute to charge transfer, such as flexibility of the backbone, redox moiety type, and distance between neighboring redox sites. In a previous work, a series of spatially defined 2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TEMPO)‐containing polymers was reported, with varied spacer lengths between the redox sites. Herein, the synthesis and characterization of spatially defined polymers is reported with the same spacing of three different redox pendants (phenothiazine, phthalimide, and dopamine) and the corresponding electrochemical properties. By doing so, the effect of solution‐polymer interactions (in both the charged and neutral states) is revealed. The apparent diffusion coefficient ( D _app ), the self‐exchange rate constant ( k _ex ), and the polymer‐solvent interactions ( χ and A ₂ ) of the phenothiazine, phthalimide, and TEMPO polymers are compared. The dopamine‐based polymer exhibits limited solubility, preventing further characterization. D _app and k _ex correlate with χ , suggesting that solvent favorability enhances charge transfer in the solution state. These findings highlight the important role that polymer‐solvent interactions play in the transfer of electrons, suggesting that a swollen polymer chain conformation promotes solution‐state electron transfer and that solvent favorability promotes charge transfer.