@article{chang_du_jamadgni_pauls_martin_wei_ward_lu_thuo_2024, title={Guided ad infinitum assembly of mixed-metal oxide arrays from a liquid metal}, volume={11}, ISSN={["2051-6355"]}, url={https://doi.org/10.1039/D4MH01177E}, DOI={10.1039/d4mh01177e}, abstractNote={Bottom-up nano- to micro-fabrication is crucial in modern electronics and optics. Conventional multi-scale array fabrication techniques, however, are facing challenges in reconciling the contradiction between the pursuit of better device performance and lowering the fabrication cost and/or energy consumption. Here, we introduce a facile mixed-metal array fabrication method based on guided self-assembly of polymerizing organometallic adducts derived from the passivating oxides of a ternary liquid metal to create mixed metal wires. Driven by capillary action and evaporation-driven Marangoni convection, large-area, high-quality organometallic nano- to micro-wire arrays were fabricated. Calcination converts the organometallics into oxides (semiconductors) without compromising wire continuity or array periodicity. Exploiting capillary bridges on a preceding layer, hierarchical arrays were made. Similarly, exploiting the conformity of the liquid to the mold, arrays with complex geometries were made. Given the periodicity and high refractive index of these arrays, we observe guided mode resonance while their complex band structures enable fabrication of diodes or gates. This work demonstrates a simple, affordable approach to opto-electronics based on self-assembling arrays.}, journal={MATERIALS HORIZONS}, author={Chang, Julia J. and Du, Chuanshen and Jamadgni, Dhanush and Pauls, Alana and Martin, Andrew and Wei, Le and Ward, Thomas and Lu, Meng and Thuo, Martin M.}, year={2024}, month={Nov} } @article{du_gregory_jamadgni_pauls_chang_dorn_martin_foster_rossini_thuo_2023, title={Spatially Directed Pyrolysis via Thermally Morphing Surface Adducts}, volume={8}, ISSN={["1521-3773"]}, url={https://doi.org/10.1002/anie.202308822}, DOI={10.1002/anie.202308822}, abstractNote={AbstractCombustion is often difficult to spatially direct or tune associated kinetics—hence a run‐away reaction. Coupling pyrolytic chemical transformation to mass transport and reaction rates (Damköhler number), however, we spatially directed ignition with concomitant switch from combustion to pyrolysis (low oxidant). A ‘surface‐then‐core’ order in ignition, with concomitant change in burning rate,is therefore established. Herein, alkysilanes grafted onto cellulose fibers are pyrolyzed into non‐flammable SiO2 terminating surface ignition propagation, hence stalling flame propagating. Sustaining high temperatures, however, triggers ignition in the bulk of the fibers but under restricted gas flow (oxidant and/or waste) hence significantly low rate of ignition propagation and pyrolysis compared to open flame (Liñán's equation). This leads to inside‐out thermal degradation and, with felicitous choice of conditions, formation of graphitic tubes. Given the temperature dependence, imbibing fibers with an exothermically oxidizing synthon (MnCl2) or a heat sink (KCl) abets or inhibits pyrolysis leading to tuneable wall thickness. We apply this approach to create magnetic, paramagnetic, or oxide containing carbon fibers. Given the surface sensitivity, we illustrate fabrication of nm‐ and μm‐diameter tubes from appropriately sized fibers.}, journal={ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, author={Du, Chuanshen and Gregory, Paul and Jamadgni, Dhanush U. and Pauls, Alana M. and Chang, Julia J. and Dorn, Rick W. and Martin, Andrew and Foster, E. Johan and Rossini, Aaron J. and Thuo, Martin}, year={2023}, month={Aug} }