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1. Vanillin: An Effective Additive to Improve the Longevity of Zn Metal Anode in a 30 m ZnCl ₂ Electrolyte

   https://doi.org/10.1002/aenm.202301712  

   Hoang, David; Li, Yaqiong; Jung, Min_Soo; Sandstrom, Sean_K; Scida, Alexis_M; Jiang, Heng; Gallagher, Trenton_C; Pollard, Brenden_A; Jensen, Rachel; Chiu, Nan‐Chieh; et al (September 2023, Advanced Energy Materials)

   Abstract It remains a challenge to design aqueous electrolytes to secure the complete reversibility of zinc metal anodes. The concentrated water‐in‐salt electrolytes, e.g., 30 m ZnCl₂, are promising candidates to address the challenges of the Zn metal anode. However, the pure 30 m ZnCl₂electrolyte fails to deliver a smooth surface morphology and a practically relevant Coulombic efficiency. Herein, it is reported that a small concentration of vanillin, 5 mg mL_water⁻¹, added to 30 m ZnCl₂transforms the reversibility of Zn metal anode by eliminating dendrites, lowering the Hammett acidity, and forming an effective solid electrolyte interphase. The presence of vanillin in the electrolyte enables the Zn metal anode to exhibit a high Coulombic efficiency of 99.34% at a low current density of 0.2 mA cm⁻², at which the impacts of the hydrogen evolution reaction are allowed to play out. Using this new electrolyte, a full cell Zn metal battery with an anode/cathode capacity (N/P) ratio of 2:1 demonstrates no capacity fading over 800 cycles. 

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2. Kinetic modeling of anaerobic degradation of plant-derived aromatic mixtures by Rhodopseudomonas palustris

   https://doi.org/10.1007/s10532-021-09932-3  

   Ma, Yanjun; Donohue, Timothy J.; Noguera, Daniel R. (April 2021, Biodegradation)

   null (Ed.)

   Abstract Rhodopseudomonas palustris is a model microorganism for studying the anaerobic metabolism of aromatic compounds. While it is well documented which aromatics can serve as sole organic carbon sources, co-metabolism of other aromatics is poorly understood. This study used kinetic modeling to analyze the simultaneous degradation of aromatic compounds present in corn stover hydrolysates and model the co-metabolism of aromatics not known to support growth of R. palustris as sole organic substrates. The simulation predicted that p -coumaroyl amide and feruloyl amide were hydrolyzed to p -coumaric acid and ferulic acid, respectively, and further transformed via p -coumaroyl-CoA and feruloyl-CoA. The modeling also suggested that metabolism of p -hydroxyphenyl aromatics was slowed by substrate inhibition, whereas the transformation of guaiacyl aromatics was inhibited by their p -hydroxyphenyl counterparts. It also predicted that substrate channeling may occur during degradation of p -coumaroyl-CoA and feruloyl-CoA, resulting in no detectable accumulation of p -hydroxybenzaldehyde and vanillin, during the transformation of these CoA ligated compounds to p- hydroxybenzoic acid and vanillic acid, respectively. While the simulation correctly represented the known transformation of p -hydroxybenzoic acid via the benzoyl-CoA pathway, it also suggested co-metabolism of vanillic acid and syringic acid, which are known not to serve as photoheterotrophic growth substrate for R. palustris . 

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3. Gate-Tuning Silicon Microring Resonator Filters for On- chip Wavelength Division Multiplexing

   https://doi.org/10.1364/CLEO_SI.2023.SM4P.5  

   Hsu, Wei-Che; Nujhat, Nabila; Kupp, Benjamin; Conley, John F.; Wang, Alan X. (January 2023, CLEO 2023)

   We demonstrated efficient gate-tuning on-chip wavelength division multiplexing filters using a silicon microring resonator array driven by high-mobility titanium-doped indium oxide gates. It shows extensive wavelength coverage for entire channel spacing over 5 nm. 

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4. Wavelength scaling of electron collision time in plasma for strong field laser-matter interactions in solids

   https://doi.org/10.1038/s42005-021-00600-9  

   Nagar, Garima C.; Dempsey, Dennis; Shim, Bonggu (May 2021, Communications Physics)

   Abstract Although the dielectric constant of plasma depends on electron collision time as well as wavelength and plasma density, experimental studies on the electron collision time and its effects on laser-matter interactions are lacking. Here, we report an anomalous regime of laser-matter interactions generated by wavelength dependence (1.2–2.3 µm) of the electron collision time in plasma for laser filamentation in solids. Our experiments using time-resolved interferometry reveal that electron collision times are small (<1 femtosecond) and decrease as the driver wavelength increases, which creates a previously-unobserved regime of light defocusing in plasma: longer wavelengths have less plasma defocusing. This anomalous plasma defocusing is counterbalanced by light diffraction which is greater at longer wavelengths, resulting in almost constant plasma densities with wavelength. Our wavelength-scaled study suggests that both the plasma density and electron collision time should be systematically investigated for a better understanding of strong field laser-matter interactions in solids. 

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5. Effect of backbone and end-group regioisomerism on thermomechanical properties of vanillin-based polyurethane networks

   https://doi.org/10.1039/D0PY01578D  

   Rangamani, Adithya; Alabi, Christopher A. (January 2021, Polymer Chemistry)

   null (Ed.)

   Monomer composition, cross-link density, and cross-link distribution are the primary determinants of material properties in thermosetting networks. Here, we investigate the effect of regioisomerism and composition in polymeric networks via a recently developed scalable sequence-defined polyurethane macromer (SD-PUM) platform. The iterative, support-free SD-PUM platform facilitates the assembly of macromers with tunable backbones and pendant groups at the gram-scale. A series of SD-PUMs made with different end-groups and vanillin positional isomers were synthesized and cross-linked into thermosetting networks via multivalent thiol cross-linkers. The results show that the thermomechanical properties of the ensuing networks are sensitive to the choice of regioisomer embedded in the SD-PUM backbone as well as the type of macromer end-group. When a cross-linker with higher functionality is employed, regioisomeric differences result in more pronounced changes in material properties. This work showcases the robustness of the SD-PUM platform and its use of backbone and end-group regioisomers to modulate material properties. 

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