@article{li_rizvi_lynch_tracy_ford_2021, title={Flexible Cyclic-Poly(phthalaldehyde)/Poly(epsilon-caprolactone) Blend Fibers with Fast Daylight-Triggered Transience}, volume={42}, ISSN={["1521-3927"]}, url={https://doi.org/10.1002/marc.202000657}, DOI={10.1002/marc.202000657}, abstractNote={Abstract Cyclic‐poly(phthalaldehyde) (cPPHA) exhibits photo‐triggerable depolymerization on‐demand for applications like the photolithography of microfabricated electronics. However, cPPHA is inherently brittle and thermally sensitive; both of these properties limit its usefulness as an engineering plastic. Prior to this report, small molecule plasticizers are added to cPPHA‐based films to make the polymer more flexible. But plasticizers can eventually leach out of cPPHA, then leaving it increasingly more brittle throughout product lifetime. In this research, a new approach to fabricating flexible cPPHA blends for use as spun fibers is achieved through the incorporation of poly (ε‐caprolactone) (PCL) by a modified wet spinning method. Among blend compositions, the 50/50 cPPHA/PCL fiber shows fast transience (<50 s) in response to daylight while retaining the flexibility of PCL and mechanical properties of an elastomer (i.e., tensile strength of ≈8 MPa, Young's modulus of ≈118 MPa, and elongation at break of ≈190%). Embedding 2 wt% gold nanoparticles to cPPHA can further improve the transience rate of fibers comprising less than 50% cPPHA. These flexible, daylight‐triggerable cPPHA/PCL fibers can be applied to an extensive range of applications, such as wearable electronics, intelligent textiles, and zero waste packaging for which modest mechanical performance and fast transience are desired.}, number={7}, journal={MACROMOLECULAR RAPID COMMUNICATIONS}, publisher={Wiley}, author={Li, Shanshan and Rizvi, Mehedi H. and Lynch, Brian B. and Tracy, Joseph B. and Ford, Ericka}, year={2021}, month={Apr} }
 @article{yadav_rizvi_kuttich_mishra_chapman_lynch_kraus_oldenburg_tracy_2021, title={Plasmon-Coupled Gold Nanoparticles in Stretched Shape-Memory Polymers for Mechanical/Thermal Sensing}, volume={4}, ISSN={["2574-0970"]}, url={https://doi.org/10.1021/acsanm.1c00309}, DOI={10.1021/acsanm.1c00309}, abstractNote={The organization of plasmonic nanoparticles (NPs) determines the strength and polarization dependence of coupling of their surface plasmons. In this study, plasmon coupling of spherical Au NPs with an average diameter of 15 nm was investigated in shape-memory polymer films before and after mechanical stretching and then after thermally driving shape recovery. Clusters of Au NPs form when preparing the films that exhibit strong plasmon coupling. During stretching, a significant polarization-dependent response develops, where the optical extinction maximum corresponding to the surface plasmon resonance is redshifted by 19 nm and blueshifted by 7 nm for polarization parallel and perpendicular to the stretching direction, respectively. This result can be explained by non-uniform stretching on the nanoscale, where plasmon coupling increases parallel to the shear direction as Au NPs are pulled into each other during stretching. The polarization dependence vanishes after shape recovery, and structural characterization confirms the return of isotropy consistent with complete nanoscale recovery of the initial arrangement of Au NPs. Simulations of the polarized optical responses of Au NP dimers at different interparticle spacings establish a plasmon ruler for estimating the average interparticle spacings within the experimental samples. An investigation of the temperature-dependent recovery behavior demonstrates an application of these materials as optical thermal history sensors.}, number={4}, journal={ACS APPLIED NANO MATERIALS}, publisher={American Chemical Society (ACS)}, author={Yadav, Prachi R. and Rizvi, Mehedi H. and Kuttich, Bjoern and Mishra, Sumeet R. and Chapman, Brian S. and Lynch, Brian B. and Kraus, Tobias and Oldenburg, Amy L. and Tracy, Joseph B.}, year={2021}, month={Apr}, pages={3911–3921} }
 @article{lynch_kelliher_anderson_japit_spencer_rizvi_sarac_augustyn_tracy_2021, title={Sulfidation and selenidation of nickel nanoparticles}, volume={3}, ISSN={["2637-9368"]}, url={https://doi.org/10.1002/cey2.83}, DOI={10.1002/cey2.83}, abstractNote={Transition metal chalcogenide nanoparticles (NPs) are of interest for energy applications, including batteries, supercapacitors, and electrocatalysis. Many methods have been established for synthesizing Ni NPs, and conversion chemistry to form Ni oxide and phosphides from template Ni NPs is well-understood. Sulfidation and selenidation of Ni NPs have been much less explored, however. We report a method for the conversion of Ni template NPs into sulfide and selenide product NPs using elemental sulfur, 1-hexadecanthiol, thiourea, trioctylphosphine sulfide, elemental selenium, and selenourea. While maintaining mole ratios of 2 mmol sulfur/selenium precursor: mmol Ni, products with phases of Ni3S2, Ni9S8, NiS, NiSO4·6H2O, Ni3S4, Ni3Se2, and NiSe have been obtained. The products have voids that form through the Kirkendall effect during interdiffusion. Trends relating the chemical properties of the precursors to the phases of the products have been identified. While some precursors contained phosphorus, there was no significant incorporation of phosphorus in any of the products. An increase of the NP size during sulfidation and selenidation is consistent with ripening. The application of Ni sulfide and selenide NPs as electrocatalysts for the hydrogen evolution reaction is also demonstrated.}, number={4}, journal={CARBON ENERGY}, publisher={Wiley}, author={Lynch, Brian B. and Kelliher, Andrew P. and Anderson, Bryan D. and Japit, Alexander and Spencer, Michael A. and Rizvi, Mehedi H. and Sarac, Mehmet F. and Augustyn, Veronica and Tracy, Joseph B.}, year={2021}, month={Aug}, pages={582–589} }
 @article{blumer_lynch_fielding_wakabayashi_2019, title={Crystallinity and Property Enhancements in Neat Polylactic Acid by Chilled Extrusion: Solid-State Shear Pulverization and Solid-State/Melt Extrusion}, volume={59}, ISSN={["1548-2634"]}, DOI={10.1002/pen.25054}, abstractNote={Polylactic acid (PLA) is a biopolymer of significant interest to both industry and the scientific community, but an incomplete understanding of the practical processing-structure-property relations is limiting its application range. The study applies alternative, chilled extrusion technologies called solid-state shear pulverization (SSSP) and solid-state/melt extrusion (SSME) to neat, commercial PLA, and investigates the effect of the resulting morphological features upon the thermomechanical behavior. Although conventional, heated twin-screw extrusion leads to significant thermal degradation of PLA chains, which in turn facilitates crystal growth due to enhanced chain mobility, chilled SSSP imparts chain defects and branching, which serve as heterogeneous nucleation sites in the polymer and promotes the formation of a rigid amorphous phase. A hybrid SSME process brings unique interplay of both chain architecture effects, resulting in a synergistic thermomechanical behavior involving the α' crystal polymorph formation. POLYM. ENG. SCI., 59:E286–E295, 2019. © 2019 Society of Plastics Engineers}, journal={POLYMER ENGINEERING AND SCIENCE}, author={Blumer, Ethan M. and Lynch, Brian B. and Fielding, Alexander S. and Wakabayashi, Katsuyuki}, year={2019}, month={Mar}, pages={E286–E295} }
 @article{ashley_vakil_lynch_dyer_tracy_owens_strouse_2017, title={Microwave Enhancement of Autocatalytic Growth of Nanometals}, volume={11}, ISSN={["1936-086X"]}, url={https://doi.org/10.1021/acsnano.7b04040}, DOI={10.1021/acsnano.7b04040}, abstractNote={The desire for designing efficient synthetic methods that lead to industrially important nanomaterials has led a desire to more fully understand the mechanism of growth and how modern synthetic techniques can be employed. Microwave (MW) synthesis is one such technique that has attracted attention as a green, sustainable method. The reports of enhancement of formation rates and improved quality for MW driven reactions are intriguing, but the lack of understanding of the reaction mechanism and how coupling to the MW field leads to these observations is concerning. In this manuscript, the growth of a metal nanoparticles (NPs) in a microwave cavity is spectroscopically analyzed and compared with the classical autocatalytic method of NP growth to elucidate the underpinnings for the observed enhanced growth behavior for metal NPs prepared in a MW field. The study illustrates that microwave synthesis of nickel and gold NPs below saturation conditions follows the Finke-Watzky mechanism of nucleation and growth. The enhancement of the reaction arises from the size-dependent increase in MW absorption cross section for the metal NPs. For Ni, the presence of oxides is considered via theoretical computations and compared to dielectric measurements of isolated nickel NPs. The study definitively shows that MW growth can be modeled by an autocatalytic mechanism that directly leads to the observed enhanced rates and improved quality widely reported in the nanomaterial community when MW irradiation is employed.}, number={10}, journal={ACS NANO}, publisher={American Chemical Society (ACS)}, author={Ashley, Bridgett and Vakil, Parth N. and Lynch, Brian B. and Dyer, Christopher M. and Tracy, Joseph B. and Owens, Jeffery and Strouse, Geoffrey F.}, year={2017}, month={Oct}, pages={9957–9967} }