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1. A Hidden Relaxation Process in Poly(2-vinylpyridine) Homopolymers, Copolymers, and Nanocomposites

   https://doi.org/10.1021/acs.macromol.2c00789  

   Young, Walter W.; Tabuchi, Hiromu; Iguchi, Ryo; Konishi, Takashi; Fukao, Koji; Katsumata, Reika (August 2022, Macromolecules)
2. Synthesis of High Refractive Index Polymer Thin Films for Soft, Flexible Optics Through Halomethane Quaternization of Poly(4‐Vinylpyridine)

   https://doi.org/10.1002/adom.202302201  

   Huo, Ni; Rivkin, Jeremy; Jia, Ruobin; Zhao, Yineng; Tenhaeff, Wyatt_E (January 2024, Advanced Optical Materials)

   Abstract Applications in soft, flexible optical, and optoelectronic applications demand polymer thin film coatings that can accommodate substantial physical deformations. The preparation of high refractive index polymers (HRIPs) through the quaternization of poly(4‐vinylpyridine) (P4VP) thin films with (di)halomethanes is presented. P4VP thin films are prepared by initiated chemical vapor deposition (iCVD) and then quaternized through exposure to saturated vapors of iodomethane (CH₃I), dibromomethane (CH₂Br₂), and diiodomethane (CH₂I₂), resulting in refractive indices (RI) as high as 1.67, 1.71, and 2.07, respectively (at 632.8 nm). Fourier‐transform infrared (FTIR) spectroscopy and X‐ray photoelectron spectroscopy (XPS) confirmed the quaternization of pyridine pendant groups on the polymer chain to n‐methylpyridinium with primarily an iodide or bromide counterion, though a minor fraction of polyiodides are also detected. Additionally, these films demonstrate superior thermal stability, retaining their refractive index and thickness after thermal excursions to 200 °C. The halogenated P4VP films exhibit superior mechanical flexibility relative to conventional inorganic coatings (Al₂O₃and Ta₂O₅) and do not fracture at uniaxial tensile strains as high as 10%. This new material chemistry and fabrication approach method may enable advanced optical designs and functionality in a wide range of substrates and device architectures. 

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3. A quantum dynamical study of the rotation of the dihydrogen ligand in the Fe(H) ₂ (H ₂ )(PEtPh ₂ ) ₃ coordination complex

   https://doi.org/10.1063/1.5026637  

   Gonzalez, Megan E.; Eckert, Juergen; Aquino, Adelia J.; Poirier, Bill (April 2018, The Journal of Chemical Physics)
4. The effect of Mg ₃ As ₂ alloying on the thermoelectric properties of n-type Mg ₃ (Sb, Bi) ₂

   https://doi.org/10.1039/D1DT01600H  

   Imasato, Kazuki; Anand, Shashwat; Gurunathan, Ramya; Snyder, G. Jeffrey (July 2021, Dalton Transactions)

   Mg 3 Sb 2 –Mg 3 Bi 2 alloys have been heavily studied as a competitive alternative to the state-of-the-art n-type Bi 2 (Te,Se) 3 thermoelectric alloys. Using Mg 3 As 2 alloying, we examine another dimension of exploration in Mg 3 Sb 2 –Mg 3 Bi 2 alloys and the possibility of further improvement of thermoelectric performance was investigated. While the crystal structure of pure Mg 3 As 2 is different from Mg 3 Sb 2 and Mg 3 Bi 2 , at least 15% arsenic solubility on the anion site (Mg 3 ((Sb 0.5 Bi 0.5 ) 1−x As x ) 2 : x = 0.15) was confirmed. Density functional theory calculations showed the possibility of band convergence by alloying Mg 3 Sb 2 –Mg 3 Bi 2 with Mg 3 As 2 . Because of only a small detrimental effect on the charge carrier mobility compared to cation site substitution, the As 5% alloyed sample showed zT = 0.6–1.0 from 350 K to 600 K. This study shows that there is an even larger composition space to examine for the optimization of material properties by considering arsenic introduction into the Mg 3 Sb 2 –Mg 3 Bi 2 system. 

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5. Unlocking the thermoelectric potential of the Ca ₁₄ AlSb ₁₁ structure type

   https://doi.org/10.1126/sciadv.abq3780  

   Justl, Andrew P.; Ricci, Francesco; Pike, Andrew; Cerretti, Giacomo; Bux, Sabah K.; Hautier, Geoffroy; Kauzlarich, Susan M. (September 2022, Science Advances)

   The interplay of synthesis, experiments, and theory in broadening the landscape of thermoelectric materials is reported. 

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