Joseph Strzalka | Argonne National Laboratory (original) (raw)

Papers by Joseph Strzalka

Nanomaterials

Magnetic-core/gold-shell nanoparticles (MAuNPs) are of interest for enabling rapid and portable d... more Magnetic-core/gold-shell nanoparticles (MAuNPs) are of interest for enabling rapid and portable detection of trace adulterants in complex media. Gold coating provides biocompatibility and facile functionalization, and a magnetic core affords analyte concentration and controlled deposition onto substrates for surface-enhanced Raman spectroscopy. Iron oxide cores were synthesized and coated with gold by reduction of HAuCl4 by NH2OH. MAuNPs were grafted with polyethylene glycol (PEG) and/or functionalized with 4-mercaptobenzoic acid (4-MBA) and examined using a variety of microscopic, spectroscopic, magnetometric, and scattering techniques. For MAuNPs grafted with both PEG and 4-MBA, the order in which they were grafted impacted not only the graft density of the individual ligands, but also the overall graft density. Significant Raman signal enhancement of the model analyte, 4-MBA, was observed. This enhancement demonstrates the functionality of MAuNPs in direct detection of trace cont...

Cooperativity is used by living systems to circumvent energetic and entropic barriers to yield hi... more Cooperativity is used by living systems to circumvent energetic and entropic barriers to yield highly efficient molecular processes. Cooperative structural transitions involve the simultaneous, concerted displacement of molecules in a crystalline material, in stark contrast to the more typical molecule-by-molecule nucleation and growth mechanism often breaking the single crystallinity. Cooperative transitions have acquired much attention in the research community for their low transition barriers, ultrafast kinetics, and structural reversibility. On the other hand, cooperative transitions are rarely observed in molecular crystals and the molecular origin is not well understood. Single crystals of 2-dimensional quinoidal terthiophene (2DQTT-o-B), a high-performance n-type organic semiconductor, demonstrate two thermally-activated, reversible phase transitions with one exhibiting a cooperative mechanism and the second exhibiting a nucleation and growth mechanism. In situ microscopy, s...

Journal of the American Chemical Society, 2022

Polymers, 2019

Polymeric binders serve to stabilize the morphology of electrodes by providing adhesion and bindi... more Polymeric binders serve to stabilize the morphology of electrodes by providing adhesion and binding between the various components. Successful binders must serve multiple functions simultaneously, including providing strong adhesion, improving conductivity, and providing electrochemical stability. A tradeoff between mechanical integrity and electrochemical performance in binders for lithium-ion batteries is one of the many challenges of improving capacity and performance. In this paper, we demonstrate a self-doped conjugated polymer, poly(9,9-bis(4′-sulfonatobutyl)fluorene-alt-co-1,4-phenylene) (PFP), which not only provides mechanical robustness but also improves electrode stability at temperatures as high as 450 °C. The self-doped PFP polymer is comprised of a conjugated polyfluorene backbone with sulfonate terminated side-chains that serve to dope the conjugated polymer backbone, resulting in stable conductivity. Composite electrodes are prepared by blending PFP with V2O5 in wate...

Chemistry of Materials, 2021

Polymorphism has emerged as an important design consideration in organic semiconductors (OSCs). P... more Polymorphism has emerged as an important design consideration in organic semiconductors (OSCs). Previously, in many OSCs, even small changes in molecular stacking can cause drastic changes to the o...

Science (New York, N.Y.), Apr 6, 2018

Light-induced structural dynamics plays a vital role in the physical properties, device performan... more Light-induced structural dynamics plays a vital role in the physical properties, device performance, and stability of hybrid perovskite-based optoelectronic devices. We report that continuous light illumination leads to a uniform lattice expansion in hybrid perovskite thin films, which is critical for obtaining high-efficiency photovoltaic devices. Correlated, in situ structural and device characterizations reveal that light-induced lattice expansion benefits the performances of a mixed-cation pure-halide planar device, boosting the power conversion efficiency from 18.5 to 20.5%. The lattice expansion leads to the relaxation of local lattice strain, which lowers the energetic barriers at the perovskite-contact interfaces, thus improving the open circuit voltage and fill factor. The light-induced lattice expansion did not compromise the stability of these high-efficiency photovoltaic devices under continuous operation at full-spectrum 1-sun (100 milliwatts per square centimeter) illu...

ACS applied materials & interfaces, Jan 12, 2017

Although spin casting and chemical surface reactions are the most common methods used for fabrica... more Although spin casting and chemical surface reactions are the most common methods used for fabricating functional polymer films onto substrates, they are limited with regard to producing films of certain morphological characteristics on different wetting and nonwetting substrates. The matrix-assisted pulsed laser evaporation (MAPLE) technique offers advantages with regard to producing films of different morphologies on different types of substrates. Here, we provide a quantitative characterization, using X-ray diffraction and optical methods, to elucidate the additive growth mechanism of MAPLE-deposited poly(3-hexylthiophene) (P3HT) films on substrates that have undergone different surface treatments, enabling them to possess different wettabilities. We show that MAPLE-deposited films are composed of crystalline phases, wherein the overall P3HT aggregate size and crystallite coherence length increase with deposition time. A complete pole figure constructed from X-ray diffraction meas...

Advanced materials (Deerfield Beach, Fla.), 2017

The influence of solvent and processing additives on the pathways and rates of crystalline morpho... more The influence of solvent and processing additives on the pathways and rates of crystalline morphology formation for spin-coated semiconducting PTB7 (poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]-thieno[3,4-b]thiophenediyl]]) thin films is investigated by in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and optical reflectance, to better understand polymer solar cell (PSC) optimization approaches. In situ characterization of PTB7 film formation from chloroform (CF), chlorobenzene (CB), and 1,2-dichlorobenzene (DCB) solutions, as well as CB solutions with 1% and 3% v/v of the processing additives 1-chloronapthalene (CN), diphenylether (DPE), and 1,8-diiodooctane (DIO), reveals multiple crystallization pathways with: (i) single-solvent systems exhibiting rapid (<3 s) crystallization after a solvent boiling point-dependent film thinning transition, (ii) solvent + additive systems exhibiting different cr...

ACS Applied Materials & Interfaces, 2017

Bulletin of the American Physical Society, Mar 4, 2015

Journal of the American Chemical Society, 2019

ACS Nano, 2010

Organic small molecule semiconductors have many advantages over their polymer analogues. However,... more Organic small molecule semiconductors have many advantages over their polymer analogues. However, to fabricate organic semiconductor-based devices using solution processing, it is requisite to eliminate dewetting to ensure film uniformity and desirable to assemble nanoscopic features with tailored macroscopic alignment without compromising their electronic properties. To this end, we present a modular supramolecular approach. A quaterthiophene organic semiconductor is attached to the side chains of poly(4-vinylpyridine) via noncovalent hydrogen bonds to form supramolecular assemblies that act as p-type semiconductors in field-effect transistors. In thin films, the quaterthiophenes can be readily assembled into microdomains, tens of nanometers in size, oriented normal to the surface. The supramolecules exhibited the same field-effect mobilities as that of the quaterthiophene alone (10(-4) cm(2)/(V.s)). Since the organic semiconductors can be readily substituted, this modular supramolecular approach is a viable method for the fabrication of functional, nanostructured organic semiconductor films using solution processing.

Labeling groups with ^2H to distinguish them in the scattering length density (SLD) profile const... more Labeling groups with ^2H to distinguish them in the scattering length density (SLD) profile constitutes the chief advantage of neutron reflectivity (NR) in studying Langmuir monolayers (LM) of lipids and proteins. Solid phase synthesis (SPPS) permits the labeling of a single residue in a peptide. Recent work demonstrates the sensitivity of NR to single ^2H-labeled residues in LM of vectorially oriented alpha -helical bundle peptides. NR requires comparison of isomorphic samples of all-^1H and ^2H-labeled peptides. Alternately, resonant x-ray reflectivity (RXR) uses only one sample. RXR exploits energy-dependent changes in the scattering factor from heavy atoms to distinguish them within the SLD profile. Peptides may be labeled by SPPS (e.g. Br-Phe), or may have inherent labels (e.g. Fe in heme proteins). As test cases, we studied LM of Br-labeled lipids and peptides with RXR. Both approaches require a model-independent means of obtaining SLD profiles from the reflectivity data. We h...

We recently [1] observed oscillations of speckle intensities from the Pt (001) surface at high te... more We recently [1] observed oscillations of speckle intensities from the Pt (001) surface at high temperatures (T > 1620K), persisting for tens of minutes. Using a model of hex-reconstructed terraces we showed that the observed oscillations come from surface dynamics due to sublimation induced step-flow motion. Our results demonstrate the possibility that coherent surface x-ray scattering (CSXS) can be applied to monitor the real-time evolution of surfaces. Hopefully CSXS can be extended further to in-situ ``real-world'' environments. This work and the use of the Advanced Photon Source were supported by the U.S. DOE, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357. The work at Safarik University was supported by VEGA 1/0138/10 and VVCE-0058-007.[4pt] [1] M.S. Pierce, et al., Appl. Phys. Lett. 99, 121910 (2011).

The this study, we investigate the mesostructure formation mechanism during aging in mesoporous t... more The this study, we investigate the mesostructure formation mechanism during aging in mesoporous titania thin films with oriented hexagonal close packed (HCP) cylindrical nanopores. Aging of titania films in a refrigerator under high humidity (approx. 94%) is an essential part of the formation of well-ordered mesostructured in titania films using titanium ethoxide as the precursor and Pluronic P123 as the pore template (e.g. Koganti et al., Nano Letters2006, 11, 2567), but the kinetics of mesostructure development and orientation have not been investigated. Preliminary investigations in our group showed that significant changes in the ordered mesostructure can continue for at least 20 minutes after film deposition, so this is the relevant time scale for further investigation. To provide orthogonal alignment of the pores, surface modification of substrates with crosslinked P123 has been used to provide a surface that is chemically neutral towards the PEO and PPO blocks of P123. Here, ...

Nanomaterials

Magnetic-core/gold-shell nanoparticles (MAuNPs) are of interest for enabling rapid and portable d... more Magnetic-core/gold-shell nanoparticles (MAuNPs) are of interest for enabling rapid and portable detection of trace adulterants in complex media. Gold coating provides biocompatibility and facile functionalization, and a magnetic core affords analyte concentration and controlled deposition onto substrates for surface-enhanced Raman spectroscopy. Iron oxide cores were synthesized and coated with gold by reduction of HAuCl4 by NH2OH. MAuNPs were grafted with polyethylene glycol (PEG) and/or functionalized with 4-mercaptobenzoic acid (4-MBA) and examined using a variety of microscopic, spectroscopic, magnetometric, and scattering techniques. For MAuNPs grafted with both PEG and 4-MBA, the order in which they were grafted impacted not only the graft density of the individual ligands, but also the overall graft density. Significant Raman signal enhancement of the model analyte, 4-MBA, was observed. This enhancement demonstrates the functionality of MAuNPs in direct detection of trace cont...

Cooperativity is used by living systems to circumvent energetic and entropic barriers to yield hi... more Cooperativity is used by living systems to circumvent energetic and entropic barriers to yield highly efficient molecular processes. Cooperative structural transitions involve the simultaneous, concerted displacement of molecules in a crystalline material, in stark contrast to the more typical molecule-by-molecule nucleation and growth mechanism often breaking the single crystallinity. Cooperative transitions have acquired much attention in the research community for their low transition barriers, ultrafast kinetics, and structural reversibility. On the other hand, cooperative transitions are rarely observed in molecular crystals and the molecular origin is not well understood. Single crystals of 2-dimensional quinoidal terthiophene (2DQTT-o-B), a high-performance n-type organic semiconductor, demonstrate two thermally-activated, reversible phase transitions with one exhibiting a cooperative mechanism and the second exhibiting a nucleation and growth mechanism. In situ microscopy, s...

Journal of the American Chemical Society, 2022

Polymers, 2019

Polymeric binders serve to stabilize the morphology of electrodes by providing adhesion and bindi... more Polymeric binders serve to stabilize the morphology of electrodes by providing adhesion and binding between the various components. Successful binders must serve multiple functions simultaneously, including providing strong adhesion, improving conductivity, and providing electrochemical stability. A tradeoff between mechanical integrity and electrochemical performance in binders for lithium-ion batteries is one of the many challenges of improving capacity and performance. In this paper, we demonstrate a self-doped conjugated polymer, poly(9,9-bis(4′-sulfonatobutyl)fluorene-alt-co-1,4-phenylene) (PFP), which not only provides mechanical robustness but also improves electrode stability at temperatures as high as 450 °C. The self-doped PFP polymer is comprised of a conjugated polyfluorene backbone with sulfonate terminated side-chains that serve to dope the conjugated polymer backbone, resulting in stable conductivity. Composite electrodes are prepared by blending PFP with V2O5 in wate...

Chemistry of Materials, 2021

Polymorphism has emerged as an important design consideration in organic semiconductors (OSCs). P... more Polymorphism has emerged as an important design consideration in organic semiconductors (OSCs). Previously, in many OSCs, even small changes in molecular stacking can cause drastic changes to the o...

Science (New York, N.Y.), Apr 6, 2018

Light-induced structural dynamics plays a vital role in the physical properties, device performan... more Light-induced structural dynamics plays a vital role in the physical properties, device performance, and stability of hybrid perovskite-based optoelectronic devices. We report that continuous light illumination leads to a uniform lattice expansion in hybrid perovskite thin films, which is critical for obtaining high-efficiency photovoltaic devices. Correlated, in situ structural and device characterizations reveal that light-induced lattice expansion benefits the performances of a mixed-cation pure-halide planar device, boosting the power conversion efficiency from 18.5 to 20.5%. The lattice expansion leads to the relaxation of local lattice strain, which lowers the energetic barriers at the perovskite-contact interfaces, thus improving the open circuit voltage and fill factor. The light-induced lattice expansion did not compromise the stability of these high-efficiency photovoltaic devices under continuous operation at full-spectrum 1-sun (100 milliwatts per square centimeter) illu...

ACS applied materials & interfaces, Jan 12, 2017

Although spin casting and chemical surface reactions are the most common methods used for fabrica... more Although spin casting and chemical surface reactions are the most common methods used for fabricating functional polymer films onto substrates, they are limited with regard to producing films of certain morphological characteristics on different wetting and nonwetting substrates. The matrix-assisted pulsed laser evaporation (MAPLE) technique offers advantages with regard to producing films of different morphologies on different types of substrates. Here, we provide a quantitative characterization, using X-ray diffraction and optical methods, to elucidate the additive growth mechanism of MAPLE-deposited poly(3-hexylthiophene) (P3HT) films on substrates that have undergone different surface treatments, enabling them to possess different wettabilities. We show that MAPLE-deposited films are composed of crystalline phases, wherein the overall P3HT aggregate size and crystallite coherence length increase with deposition time. A complete pole figure constructed from X-ray diffraction meas...

Advanced materials (Deerfield Beach, Fla.), 2017

The influence of solvent and processing additives on the pathways and rates of crystalline morpho... more The influence of solvent and processing additives on the pathways and rates of crystalline morphology formation for spin-coated semiconducting PTB7 (poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]-thieno[3,4-b]thiophenediyl]]) thin films is investigated by in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and optical reflectance, to better understand polymer solar cell (PSC) optimization approaches. In situ characterization of PTB7 film formation from chloroform (CF), chlorobenzene (CB), and 1,2-dichlorobenzene (DCB) solutions, as well as CB solutions with 1% and 3% v/v of the processing additives 1-chloronapthalene (CN), diphenylether (DPE), and 1,8-diiodooctane (DIO), reveals multiple crystallization pathways with: (i) single-solvent systems exhibiting rapid (<3 s) crystallization after a solvent boiling point-dependent film thinning transition, (ii) solvent + additive systems exhibiting different cr...

ACS Applied Materials & Interfaces, 2017

Bulletin of the American Physical Society, Mar 4, 2015

Journal of the American Chemical Society, 2019

ACS Nano, 2010

Organic small molecule semiconductors have many advantages over their polymer analogues. However,... more Organic small molecule semiconductors have many advantages over their polymer analogues. However, to fabricate organic semiconductor-based devices using solution processing, it is requisite to eliminate dewetting to ensure film uniformity and desirable to assemble nanoscopic features with tailored macroscopic alignment without compromising their electronic properties. To this end, we present a modular supramolecular approach. A quaterthiophene organic semiconductor is attached to the side chains of poly(4-vinylpyridine) via noncovalent hydrogen bonds to form supramolecular assemblies that act as p-type semiconductors in field-effect transistors. In thin films, the quaterthiophenes can be readily assembled into microdomains, tens of nanometers in size, oriented normal to the surface. The supramolecules exhibited the same field-effect mobilities as that of the quaterthiophene alone (10(-4) cm(2)/(V.s)). Since the organic semiconductors can be readily substituted, this modular supramolecular approach is a viable method for the fabrication of functional, nanostructured organic semiconductor films using solution processing.

Labeling groups with ^2H to distinguish them in the scattering length density (SLD) profile const... more Labeling groups with ^2H to distinguish them in the scattering length density (SLD) profile constitutes the chief advantage of neutron reflectivity (NR) in studying Langmuir monolayers (LM) of lipids and proteins. Solid phase synthesis (SPPS) permits the labeling of a single residue in a peptide. Recent work demonstrates the sensitivity of NR to single ^2H-labeled residues in LM of vectorially oriented alpha -helical bundle peptides. NR requires comparison of isomorphic samples of all-^1H and ^2H-labeled peptides. Alternately, resonant x-ray reflectivity (RXR) uses only one sample. RXR exploits energy-dependent changes in the scattering factor from heavy atoms to distinguish them within the SLD profile. Peptides may be labeled by SPPS (e.g. Br-Phe), or may have inherent labels (e.g. Fe in heme proteins). As test cases, we studied LM of Br-labeled lipids and peptides with RXR. Both approaches require a model-independent means of obtaining SLD profiles from the reflectivity data. We h...

We recently [1] observed oscillations of speckle intensities from the Pt (001) surface at high te... more We recently [1] observed oscillations of speckle intensities from the Pt (001) surface at high temperatures (T > 1620K), persisting for tens of minutes. Using a model of hex-reconstructed terraces we showed that the observed oscillations come from surface dynamics due to sublimation induced step-flow motion. Our results demonstrate the possibility that coherent surface x-ray scattering (CSXS) can be applied to monitor the real-time evolution of surfaces. Hopefully CSXS can be extended further to in-situ ``real-world'' environments. This work and the use of the Advanced Photon Source were supported by the U.S. DOE, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357. The work at Safarik University was supported by VEGA 1/0138/10 and VVCE-0058-007.[4pt] [1] M.S. Pierce, et al., Appl. Phys. Lett. 99, 121910 (2011).

The this study, we investigate the mesostructure formation mechanism during aging in mesoporous t... more The this study, we investigate the mesostructure formation mechanism during aging in mesoporous titania thin films with oriented hexagonal close packed (HCP) cylindrical nanopores. Aging of titania films in a refrigerator under high humidity (approx. 94%) is an essential part of the formation of well-ordered mesostructured in titania films using titanium ethoxide as the precursor and Pluronic P123 as the pore template (e.g. Koganti et al., Nano Letters2006, 11, 2567), but the kinetics of mesostructure development and orientation have not been investigated. Preliminary investigations in our group showed that significant changes in the ordered mesostructure can continue for at least 20 minutes after film deposition, so this is the relevant time scale for further investigation. To provide orthogonal alignment of the pores, surface modification of substrates with crosslinked P123 has been used to provide a surface that is chemically neutral towards the PEO and PPO blocks of P123. Here, ...