Aubrey Dyer | Clayton State University (original) (raw)
Papers by Aubrey Dyer
3To achieve high optical contrasts in the visible region, two complimentary electrochromic materi... more 3To achieve high optical contrasts in the visible region, two complimentary electrochromic materials are typically utilized, one cathodically coloring and the other anodically coloring. In dual polymer electrochromic devices, the anodically coloring material has a high bandgap, with the polymer being transmissive in the neutral state and becoming colored upon oxidation. The cathodically coloring polymer has a relatively low bandgap and is colored when neutral and transmissive upon oxidation. An example of this type of device is one in which the anodically coloring polymer is an N-substituted propylenedioxypyrrole, such as PProDOP-NPrS, and the cathodically coloring polymer is a dialkyl-substituted propylenedioxythiophene, such as PProDOT-(CH3)2. The colors exhibited by the device are an additive combination of those exhibited by the individual polymers yielding a high contrast of ca. 70% in the visible region. Absorptive/transmissive devices can also be hybrid-type with one of the e...
Conjugated conducting polymers are among some of the most versatile materials to emerge in the pa... more Conjugated conducting polymers are among some of the most versatile materials to emerge in the past 20 years. They have been researched for applications that range from photovoltaics, to light-emitting diodes, electrochromic windows, actuators, and field effect transistors. This work details the analytical characterization of pi-conjugated polymers to understand their redox and optical properties, along with the development of several
Advanced Functional Materials, 2015
The fi eld of organic electrochromics is reviewed here, with particular focus on how the "electro... more The fi eld of organic electrochromics is reviewed here, with particular focus on how the "electrochromic" as a functional material can be brought from the current level of accurate laboratory synthesis and characterization to the device and application level through a number of suited roll-to-roll methods compatible with upscaling and manufacture. The successful approaches to operational devices are presented in detail, as well as areas where future research would have a high impact and accelerate the development such as highly conducting and transparent substrates, electrolytes adapted for multilayer application and morphologically stable conjugated polymers.
ACS Applied Materials & Interfaces, 2015
We report a straightforward strategy of accessing a wide variety of colors through simple predict... more We report a straightforward strategy of accessing a wide variety of colors through simple predictive color mixing of electrochromic polymers (ECPs). We have created a set of brown ECP blends that can be incorporated as the active material in user-controlled electrochromic eyewear. Color mixing of ECPs proceeds in a subtractive fashion, and we acquire various hues of brown through the mixing of cyan and yellow primaries in combination with orange and periwinkle-blue secondary colors. Upon oxidation, all of the created blends exhibit a change in transmittance from ca. 10 to 70% in a few seconds. We demonstrate the attractiveness of these ECP blends as active materials in electrochromic eyewear by assembling user-controlled, high-contrast, fast-switching, and fully solution-processable electrochromic lenses with colorless transmissive states and colored states that correspond to commercially available sunglasses. The lenses were fabricated using a combination of inkjet printing and blade-coating to illustrate the feasibility of using soluble ECPs for high-throughput and large-scale processing.
2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2011
In this work, we develop an experimental testbed that couples biotic and abiotic metrics for stud... more In this work, we develop an experimental testbed that couples biotic and abiotic metrics for studying, quantifying and predicting the effects of chronic electrode implantation on neural electrode performance. The rationale is based on the observation that long-term functionality is the outcome of the interactions between the dynamics of the neuronal environment and the properties of the electrode itself. By combining and analyzing the substantially richer information available in the spatiotemporal dynamics of neurons with biotic and abiotic metrics such as biochemical markers, histochemistry, SEM imaging, and electrochemistry, we seek to quantitatively improve our understanding of the functional modifications underlying the long-term responses of electrode implants. The goal is to ultimately enable the design of future reliable interfaces. In our preliminary analysis using this biotic-abiotic approach of an electrode 18 days post-implant, we observed both structural and histochemical responses related to chronic electrode implantation. These were coupled to daily functional changes in electrode performance. Interestingly, these changes were not correlated with markers of brain injury at the time of electrode explantation. Future work using this multidisciplinary approach is directed to providing a detailed perspective into long-term microelectrode performance.
ACS Applied Materials & Interfaces, 2015
Electrochromic polymers (ECPs) have been shown to be synthetically tunable, producing a full pale... more Electrochromic polymers (ECPs) have been shown to be synthetically tunable, producing a full palette of vibrantly colored to highly transmissive polymers. The development of these colored-to-transmissive ECPs employed synthetic design strategies for broad color targeting; however, due to the subtleties of color perception and the intricacies of polymer structure and color relationships, fine color control is difficult. In contrast, color mixing is a well-established practice in the printing industry. We have identified three colored-to-transmissive switching electrochromic polymers, referred to as ECP-Cyan (ECP-C), ECP-Magenta (ECP-M), and ECP-Yellow (ECP-Y), which, via the co-processing of multicomponent ECP mixtures, follow the CMY color mixing model. The presented work qualitatively assesses the thin film characteristics of solution co-processed ECP mixtures. To quantitatively determine the predictability of the color properties of ECP mixtures, we estimated mass extinction coefficients (ε mass) from solution spectra of the CMY ECPs and compared the estimated and experimentally observed color values of blends via a calculated color difference (ΔE ab). The values of ΔE ab range from 8 to 26 across all mixture compositions, with an average value of 15, representing a reasonable degree of agreement between predicted and observed color values. We demonstrate here the ability to co-process ECP mixtures into vibrantly colored, visually continuous films and the ability to estimate the color properties produced in these mixed ECP films.
J. Mater. Chem. A, 2014
A fractional factorial design of experiments allowed us to optimize the areal capacitance of elec... more A fractional factorial design of experiments allowed us to optimize the areal capacitance of electropolymerized films over 7 variables using a dramatically reduced set of experiments.
Solar Energy Materials and Solar Cells, 2012
ABSTRACT The performance of a desiccant-filled polyisobutylene edge sealant for organic electroni... more ABSTRACT The performance of a desiccant-filled polyisobutylene edge sealant for organic electronics is reported. The sealant was applied through a low temperature lamination process using glass substrates and various seal widths. The performance was tested using the Ca corrosion method at 50 °C and 80% relative humidity (RH). Data show an effective water vapor transmission rate (WVTR), on the order of 10−3 g/m2/day in the transient regime with a breakthrough time greater than 1400 h for seals 1.5 mm wide and 0.3 mm thick. By changing the sealant architecture, the breakthrough time was increased with similar effective WVTRs. Finally, the sealant was applied to organic electrochromic devices, which displayed a retention of performance after 1000 h of storage at 50 °C and 80% RH.
Macromolecules, 2012
ABSTRACT Poly[6,6′-bis(ethylene-3,4-dioxythien-2-yl)]-N,N′-dialkylisoindigo (PBEDOT-iI) was synth... more ABSTRACT Poly[6,6′-bis(ethylene-3,4-dioxythien-2-yl)]-N,N′-dialkylisoindigo (PBEDOT-iI) was synthesized and incorporated as an electroactive material into electrochemical supercapacitors (ESCs) in type I and type III configurations. In type I ESCs, PBEDOT-iI provides a specific power of 360 W/kg and specific energy of 0.5 Wh/kg, while retaining about 80% of its electroactivity over 10 000 cycles. In addition, we report on the use of PBEDOT-iI in type III supercapacitors where operating voltages as high as 2.5 V were achieved with specific energies of ca. 15 Wh/kg, albeit with limited stability.
Journal of the American Chemical Society, 2011
A combination of electrochromism and electroluminescence in functional materials could lead to si... more A combination of electrochromism and electroluminescence in functional materials could lead to single-layer dual electrochromic/electroluminescent (EC/EL) display devices, capable of simultaneous operation in emissive and reflective modes. Whereas such next generation displays could provide optimal visibility in any ambient lighting situation, materials available that exhibit such characteristics in the active layer are limited due to the required intrinsic multifunctionality (i.e., redox activity, electroluminescence, electrochromism, and ion conductivity) and to date can only be achieved via the rational design of ionic transition-metal complexes. Reported herein is the synthesis and characterization of a new family of acrylate-containing ruthenium (tris)bipyridine-based coordination complexes with multifunctional characteristics. Potential use of the presented compounds in EC/EL devices is established, as they are applied as cross-linked electrochromic films and electrochemiluminescent layers in light-emitting electrochemical cell devices. Electrochromic switching of the polymeric networks between yellow, orange, green, brown and transmissive states is demonstrated, and electrochemiluminescent devices based on the complexes synthesized show red-orange to deep red emission with λ max ranging from 680 to 722 nm and luminance up to 135 cd/m 2. Additionally, a dual EC/EL device prototype is presented where light emission and multicolor electrochromism occur from the same pixel comprised of a single active layer, demonstrating a true combination of these properties in ionic transition-metal complexes.
Journal of Polymer Science Part B: Polymer Physics, 2012
Electrochromic devices (ECDs) were prepared on flexible substrates using spray coating and slot-d... more Electrochromic devices (ECDs) were prepared on flexible substrates using spray coating and slot-die coating methods. The electrochromic materials were the conjugated electroactive polymers, poly((2,2-bis(2-ethylhexyloxymethyl)-propylene-1,3-dioxy)-3,4-thiophene-2,5-diyl) as a vibrantly colored active material (ECP-Magenta) and poly(N-octadecyl-(propylene-1,3dioxy)-3,4-pyrrole-2,5-diyl) as a minimally colored, charge balancing material (MCCP). Two electrolyte systems were compared to allow development of fully printable and laminated devices on flexible substrates. Devices of various sizes, up to 7 Â 8 cm 2 , are demonstrated with pixelated devices containing pixel sizes of 4 Â 4 mm 2 or 13 Â 13 mm 2. The transmission contrast exhibited by the devices, when switched between the fully bleached and fully colored state, was 58% at a visible wavelength of 550 nm, and the devices exhibited switching times of <10 s. Additionally, we demonstrate the utilization of printed organic photovoltaic devices (with or without the use of a lithium-polymer battery) to power the devices between the colored and bleached state, illustrating a self-powered ECD. V
Journal of Materials Chemistry, 2012
RSC Publishing Logo View PDF Version DOI:10.1039/C2JM15057C (Paper) J. Mater. Chem., 2012, Advanc... more RSC Publishing Logo View PDF Version DOI:10.1039/C2JM15057C (Paper) J. Mater. Chem., 2012, Advance Article. A minimally coloured dioxypyrrole polymer as a counter electrode material in polymeric electrochromic window devices†. ...
Journal of Materials Chemistry, 2007
J. Mater. Chem., 2007, 17, 225-231 DOI:10.1039/B613879A (Paper). Electrochromic properties of a f... more J. Mater. Chem., 2007, 17, 225-231 DOI:10.1039/B613879A (Paper). Electrochromic properties of a fast switching, dual colour polythiophene bearing non-planar dithiinoquinoxaline units. Rory Berridgea, Shaun P. Wrighta, Peter ...
3To achieve high optical contrasts in the visible region, two complimentary electrochromic materi... more 3To achieve high optical contrasts in the visible region, two complimentary electrochromic materials are typically utilized, one cathodically coloring and the other anodically coloring. In dual polymer electrochromic devices, the anodically coloring material has a high bandgap, with the polymer being transmissive in the neutral state and becoming colored upon oxidation. The cathodically coloring polymer has a relatively low bandgap and is colored when neutral and transmissive upon oxidation. An example of this type of device is one in which the anodically coloring polymer is an N-substituted propylenedioxypyrrole, such as PProDOP-NPrS, and the cathodically coloring polymer is a dialkyl-substituted propylenedioxythiophene, such as PProDOT-(CH3)2. The colors exhibited by the device are an additive combination of those exhibited by the individual polymers yielding a high contrast of ca. 70% in the visible region. Absorptive/transmissive devices can also be hybrid-type with one of the e...
Conjugated conducting polymers are among some of the most versatile materials to emerge in the pa... more Conjugated conducting polymers are among some of the most versatile materials to emerge in the past 20 years. They have been researched for applications that range from photovoltaics, to light-emitting diodes, electrochromic windows, actuators, and field effect transistors. This work details the analytical characterization of pi-conjugated polymers to understand their redox and optical properties, along with the development of several
Advanced Functional Materials, 2015
The fi eld of organic electrochromics is reviewed here, with particular focus on how the "electro... more The fi eld of organic electrochromics is reviewed here, with particular focus on how the "electrochromic" as a functional material can be brought from the current level of accurate laboratory synthesis and characterization to the device and application level through a number of suited roll-to-roll methods compatible with upscaling and manufacture. The successful approaches to operational devices are presented in detail, as well as areas where future research would have a high impact and accelerate the development such as highly conducting and transparent substrates, electrolytes adapted for multilayer application and morphologically stable conjugated polymers.
ACS Applied Materials & Interfaces, 2015
We report a straightforward strategy of accessing a wide variety of colors through simple predict... more We report a straightforward strategy of accessing a wide variety of colors through simple predictive color mixing of electrochromic polymers (ECPs). We have created a set of brown ECP blends that can be incorporated as the active material in user-controlled electrochromic eyewear. Color mixing of ECPs proceeds in a subtractive fashion, and we acquire various hues of brown through the mixing of cyan and yellow primaries in combination with orange and periwinkle-blue secondary colors. Upon oxidation, all of the created blends exhibit a change in transmittance from ca. 10 to 70% in a few seconds. We demonstrate the attractiveness of these ECP blends as active materials in electrochromic eyewear by assembling user-controlled, high-contrast, fast-switching, and fully solution-processable electrochromic lenses with colorless transmissive states and colored states that correspond to commercially available sunglasses. The lenses were fabricated using a combination of inkjet printing and blade-coating to illustrate the feasibility of using soluble ECPs for high-throughput and large-scale processing.
2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2011
In this work, we develop an experimental testbed that couples biotic and abiotic metrics for stud... more In this work, we develop an experimental testbed that couples biotic and abiotic metrics for studying, quantifying and predicting the effects of chronic electrode implantation on neural electrode performance. The rationale is based on the observation that long-term functionality is the outcome of the interactions between the dynamics of the neuronal environment and the properties of the electrode itself. By combining and analyzing the substantially richer information available in the spatiotemporal dynamics of neurons with biotic and abiotic metrics such as biochemical markers, histochemistry, SEM imaging, and electrochemistry, we seek to quantitatively improve our understanding of the functional modifications underlying the long-term responses of electrode implants. The goal is to ultimately enable the design of future reliable interfaces. In our preliminary analysis using this biotic-abiotic approach of an electrode 18 days post-implant, we observed both structural and histochemical responses related to chronic electrode implantation. These were coupled to daily functional changes in electrode performance. Interestingly, these changes were not correlated with markers of brain injury at the time of electrode explantation. Future work using this multidisciplinary approach is directed to providing a detailed perspective into long-term microelectrode performance.
ACS Applied Materials & Interfaces, 2015
Electrochromic polymers (ECPs) have been shown to be synthetically tunable, producing a full pale... more Electrochromic polymers (ECPs) have been shown to be synthetically tunable, producing a full palette of vibrantly colored to highly transmissive polymers. The development of these colored-to-transmissive ECPs employed synthetic design strategies for broad color targeting; however, due to the subtleties of color perception and the intricacies of polymer structure and color relationships, fine color control is difficult. In contrast, color mixing is a well-established practice in the printing industry. We have identified three colored-to-transmissive switching electrochromic polymers, referred to as ECP-Cyan (ECP-C), ECP-Magenta (ECP-M), and ECP-Yellow (ECP-Y), which, via the co-processing of multicomponent ECP mixtures, follow the CMY color mixing model. The presented work qualitatively assesses the thin film characteristics of solution co-processed ECP mixtures. To quantitatively determine the predictability of the color properties of ECP mixtures, we estimated mass extinction coefficients (ε mass) from solution spectra of the CMY ECPs and compared the estimated and experimentally observed color values of blends via a calculated color difference (ΔE ab). The values of ΔE ab range from 8 to 26 across all mixture compositions, with an average value of 15, representing a reasonable degree of agreement between predicted and observed color values. We demonstrate here the ability to co-process ECP mixtures into vibrantly colored, visually continuous films and the ability to estimate the color properties produced in these mixed ECP films.
J. Mater. Chem. A, 2014
A fractional factorial design of experiments allowed us to optimize the areal capacitance of elec... more A fractional factorial design of experiments allowed us to optimize the areal capacitance of electropolymerized films over 7 variables using a dramatically reduced set of experiments.
Solar Energy Materials and Solar Cells, 2012
ABSTRACT The performance of a desiccant-filled polyisobutylene edge sealant for organic electroni... more ABSTRACT The performance of a desiccant-filled polyisobutylene edge sealant for organic electronics is reported. The sealant was applied through a low temperature lamination process using glass substrates and various seal widths. The performance was tested using the Ca corrosion method at 50 °C and 80% relative humidity (RH). Data show an effective water vapor transmission rate (WVTR), on the order of 10−3 g/m2/day in the transient regime with a breakthrough time greater than 1400 h for seals 1.5 mm wide and 0.3 mm thick. By changing the sealant architecture, the breakthrough time was increased with similar effective WVTRs. Finally, the sealant was applied to organic electrochromic devices, which displayed a retention of performance after 1000 h of storage at 50 °C and 80% RH.
Macromolecules, 2012
ABSTRACT Poly[6,6′-bis(ethylene-3,4-dioxythien-2-yl)]-N,N′-dialkylisoindigo (PBEDOT-iI) was synth... more ABSTRACT Poly[6,6′-bis(ethylene-3,4-dioxythien-2-yl)]-N,N′-dialkylisoindigo (PBEDOT-iI) was synthesized and incorporated as an electroactive material into electrochemical supercapacitors (ESCs) in type I and type III configurations. In type I ESCs, PBEDOT-iI provides a specific power of 360 W/kg and specific energy of 0.5 Wh/kg, while retaining about 80% of its electroactivity over 10 000 cycles. In addition, we report on the use of PBEDOT-iI in type III supercapacitors where operating voltages as high as 2.5 V were achieved with specific energies of ca. 15 Wh/kg, albeit with limited stability.
Journal of the American Chemical Society, 2011
A combination of electrochromism and electroluminescence in functional materials could lead to si... more A combination of electrochromism and electroluminescence in functional materials could lead to single-layer dual electrochromic/electroluminescent (EC/EL) display devices, capable of simultaneous operation in emissive and reflective modes. Whereas such next generation displays could provide optimal visibility in any ambient lighting situation, materials available that exhibit such characteristics in the active layer are limited due to the required intrinsic multifunctionality (i.e., redox activity, electroluminescence, electrochromism, and ion conductivity) and to date can only be achieved via the rational design of ionic transition-metal complexes. Reported herein is the synthesis and characterization of a new family of acrylate-containing ruthenium (tris)bipyridine-based coordination complexes with multifunctional characteristics. Potential use of the presented compounds in EC/EL devices is established, as they are applied as cross-linked electrochromic films and electrochemiluminescent layers in light-emitting electrochemical cell devices. Electrochromic switching of the polymeric networks between yellow, orange, green, brown and transmissive states is demonstrated, and electrochemiluminescent devices based on the complexes synthesized show red-orange to deep red emission with λ max ranging from 680 to 722 nm and luminance up to 135 cd/m 2. Additionally, a dual EC/EL device prototype is presented where light emission and multicolor electrochromism occur from the same pixel comprised of a single active layer, demonstrating a true combination of these properties in ionic transition-metal complexes.
Journal of Polymer Science Part B: Polymer Physics, 2012
Electrochromic devices (ECDs) were prepared on flexible substrates using spray coating and slot-d... more Electrochromic devices (ECDs) were prepared on flexible substrates using spray coating and slot-die coating methods. The electrochromic materials were the conjugated electroactive polymers, poly((2,2-bis(2-ethylhexyloxymethyl)-propylene-1,3-dioxy)-3,4-thiophene-2,5-diyl) as a vibrantly colored active material (ECP-Magenta) and poly(N-octadecyl-(propylene-1,3dioxy)-3,4-pyrrole-2,5-diyl) as a minimally colored, charge balancing material (MCCP). Two electrolyte systems were compared to allow development of fully printable and laminated devices on flexible substrates. Devices of various sizes, up to 7 Â 8 cm 2 , are demonstrated with pixelated devices containing pixel sizes of 4 Â 4 mm 2 or 13 Â 13 mm 2. The transmission contrast exhibited by the devices, when switched between the fully bleached and fully colored state, was 58% at a visible wavelength of 550 nm, and the devices exhibited switching times of <10 s. Additionally, we demonstrate the utilization of printed organic photovoltaic devices (with or without the use of a lithium-polymer battery) to power the devices between the colored and bleached state, illustrating a self-powered ECD. V
Journal of Materials Chemistry, 2012
RSC Publishing Logo View PDF Version DOI:10.1039/C2JM15057C (Paper) J. Mater. Chem., 2012, Advanc... more RSC Publishing Logo View PDF Version DOI:10.1039/C2JM15057C (Paper) J. Mater. Chem., 2012, Advance Article. A minimally coloured dioxypyrrole polymer as a counter electrode material in polymeric electrochromic window devices†. ...
Journal of Materials Chemistry, 2007
J. Mater. Chem., 2007, 17, 225-231 DOI:10.1039/B613879A (Paper). Electrochromic properties of a f... more J. Mater. Chem., 2007, 17, 225-231 DOI:10.1039/B613879A (Paper). Electrochromic properties of a fast switching, dual colour polythiophene bearing non-planar dithiinoquinoxaline units. Rory Berridgea, Shaun P. Wrighta, Peter ...