@article{clark_thacker_mcgill_miles_westmoreland_efimenko_genzer_santiso_2021, title={DFT Analysis of Organotin Catalytic Mechanisms in Dehydration Esterification Reactions for Terephthalic Acid and 2,2,4,4-Tetramethyl-1,3-cyclobutanediol}, volume={125}, ISSN={["1520-5215"]}, url={https://doi.org/10.1021/acs.jpca.1c00850}, DOI={10.1021/acs.jpca.1c00850}, abstractNote={Polyesters synthesized from 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCD) and terephthalic acid (TPA) are improved alternatives to toxic polycarbonates based on bisphenol A. In this work, we use ωB97X-D/LANL2DZdp calculations, in the presence of a benzaldehyde polarizable continuum model solvent, to show that esterification of TMCD and TPA will reduce and subsequently dehydrate a dimethyl tin oxide catalyst, becoming ligands on the now four-coordinate complex. This reaction then proceeds most plausibly by an intramolecular acyl-transfer mechanism from the tin complex, aided by a coordinated proton donor such as hydronium. These findings are a key first step in understanding polyester synthesis and avoiding undesirable side reactions during production.}, number={23}, journal={JOURNAL OF PHYSICAL CHEMISTRY A}, publisher={American Chemical Society (ACS)}, author={Clark, Jennifer A. and Thacker, Pranav J. and McGill, Charles J. and Miles, Jason R. and Westmoreland, Phillip R. and Efimenko, Kirill and Genzer, Jan and Santiso, Erik E.}, year={2021}, month={Jun}, pages={4943–4956} }
 @article{miles_ko_genzer_2020, title={Dependence of deposition method on the molecular structure and stability of organosilanes revealed from degrafting by tetrabutylammonium fluoride}, volume={22}, ISSN={["1463-9084"]}, DOI={10.1039/c9cp05221f}, abstractNote={We probe the structure of self-assembled monolayers comprising organosilanes on flat silica-based surfaces prepared by liquid and vapor deposition by removing the organosilane molecules gradually from the substrate via tetrabutylammonium fluoride.}, number={2}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Miles, Jason and Ko, Yeongun and Genzer, Jan}, year={2020}, month={Jan}, pages={658–666} }
 @article{ko_miles_genzer_2019, title={Determining Water Sorption and Desorption in Thin Hydrophilic Polymer Films by Thermal Treatment}, volume={1}, ISSN={["2637-6105"]}, DOI={10.1021/acsapm.9b00607}, abstractNote={Knowledge of dry thickness of polymer films is required to determine the areal density of polymeric grafts and the degree of swelling of polymer networks and surface-anchored polymer assemblies. Because hydrophilic polymer films absorb water at ambient conditions and retain it, it is challenging to establish accurate dry thickness in such systems. Here we report on determining water uptake by chargeable/charged polymer films by monitoring the coefficient of thermal expansion (CTE) and thermo-optic coefficient (TOC) using ellipsometry. Knowing accurate amount of moisture in polymer films is needed for numerous applications, including, humidity and temperature sensors, polymer nanoreactors, lubricating coatings, antibacterial surfaces, and many others.}, number={9}, journal={ACS APPLIED POLYMER MATERIALS}, author={Ko, Yeongun and Miles, Jason R. and Genzer, Jan}, year={2019}, month={Sep}, pages={2495–2502} }
 @article{patil_miles_ko_datta_rao_kiserow_genzer_2018, title={Kinetic Study of Degrafting Poly(methyl methacrylate) Brushes from Flat Substrates by Tetrabutylammonium Fluoride}, volume={51}, ISSN={["1520-5835"]}, DOI={10.1021/acs.macromol.8b01832}, abstractNote={Polymer degrafting is a process in which surface-attached polymer brushes are removed from the substrate by breaking a chemical bond in proximity to the substrate. This paper provides insight into the kinetics of degrafting poly(methyl methacrylate) (PMMA) brushes using tetrabutylammonium fluoride (TBAF) and demonstrates how the process can be modeled using a series of degrafting reactions. The trichlorosilane-based polymerization initiator utilized here to synthesize PMMA grafts by surface-initiated atom transfer radical polymerization anchors to the silica substrate by up to three potential attachment points. During the degrafting sequence this anchoring reduces to two and one chemical bond and finally results in complete liberation of the PMMA macromolecule from the substrate. We investigate the effect of TBAF concentration, the initial grafting density of PMMA grafts on the substrate, and TBAF exposure time on degrafting of PMMA by monitoring the instantaneous areal grafting density of PMMA on the sub...}, number={24}, journal={MACROMOLECULES}, author={Patil, Rohan and Miles, Jason and Ko, Yeongun and Datta, Preeta and Rao, Balaji M. and Kiserow, Douglas and Genzer, Jan}, year={2018}, month={Dec}, pages={10237–10245} }
 @article{miles_schlenker_ko_patil_rao_genzer_2017, title={Design and Fabrication of Wettability Gradients with Tunable Profiles through Degrafting Organosilane Layers from Silica Surfaces by Tetrabutylammonium Fluoride}, volume={33}, ISSN={["0743-7463"]}, DOI={10.1021/acs.langmuir.7b02961}, abstractNote={Surface-bound wettability gradients allow for a high-throughput approach to evaluate surface interactions for many biological and chemical processes. Here we describe the fabrication of surface wettability gradients on flat surfaces by a simple, two-step procedure that permits precise tuning of the gradient profile. This process involves the deposition of homogeneous silane SAMs followed by the formation of a surface coverage gradient through the selective removal of silanes from the substrate. Removal of silanes from the surface is achieved by using tetrabutylammonium fluoride which selectively cleaves the Si-O bonds at the headgroup of the silane. The kinetics of degrafting has been modeled by using a series of first order rate equations, based on the number of attachment points broken to remove a silane from the surface. Degrafting of monofunctional silanes exhibits a single exponential decay in surface coverage; however, there is a delay in degrafting of trifunctional silanes due to the presence of multiple attachment points. The effects of degrafting temperature and time are examined in detail and demonstrate the ability to reliably and precisely control the gradient profile on the surface. We observe a relatively homogeneous coverage of silane (i.e., without the presence of islands or holes) throughout the degrafting process, providing a much more uniform surface when compared to additive approaches of gradient formation. Linear gradients were formed on the substrates to demonstrate the reproducibility and tuneability of this subtractive approach.}, number={51}, journal={LANGMUIR}, author={Miles, Jason and Schlenker, Spencer and Ko, Yeongun and Patil, Rohan and Rao, Balaji M. and Genzer, Jan}, year={2017}, month={Dec}, pages={14556–14564} }