Gregory A. Sotzing

University of Connecticut | UConn · Department of Chemistry

Cannabidiol (CBD) containing products have flooded consumer markets in the past few years as the United States, Canada, and several European countries have legalized the cultivation of hemp. Due to complex legal histories of marijuana and cannabinoids, the stability and safety of CBD is still largely uncertain as research has been restricted global...

Introduction: In the last decade, the market for Cannabidiol (CBD) has grown to become a near $2 billion dollar industry in the United States alone. This growth can be attributed to a growing social acceptance of marijuana, a more detailed understanding of many health benefits attributed to cannabinoids, and the low cost and wide availibility of he...

All-organic, flexible, and body-compatible loudspeakers have become increasingly attractive for wearable electronics. Due to their remarkable piezoelectric response, ferroelectrets are suitable for loudspeakers. Two distinct kinds of ultrathin ferroelectrets, including cellular polypropylene films and expanded polytetrafluoroethylene (ePTFE) films,...

The legalization of hemp cultivation in the United States has caused the price of hemp-derived cannabinoids to decrease 10-fold within 2 years. Cannabidiol (CBD), one of many naturally occurring diols found in hemp, can be purified in high yield for low cost, making it an interesting candidate for polymer feedstock. In this study, two polyesters we...

In contrast to molecular-dipole polymers, such as PVDF, ferroelectrets are a new class of flexible spatially heterogeneous piezoelectric polymers with closed or open voids that act as deformable macro-dipoles after charging. With a spectrum of manufacturing processes being developed to engineer the heterogeneous structures, ferroelectrets are made...

Advanced polymer dielectrics are desired for high-temperature, high-density, and high-efficiency energy storage. The paradox of mutually exclusive constraints between high field endurance, dielectric polarization, and thermal stability amounts to a huge obstacle in the design of all-organic polymer dielectrics for safe operation under harsh conditi...

A paradigm-shifting design strategy is demonstrated that unifies the treatment of electronic and conformational properties of polymer dielectrics for concurrent high electric field and elevated temperature harsh conditions.

Polymer dielectrics with ultra-high charge-discharge rates are significant for advanced electrical and electronic systems. Despite the fact that polymers possess high breakdown strength, the low dielectric constant (k) of polymers gives rise to low energy densities. Incorporating metal into polyimides (PI) at the polyamic acid (PAA) precursor stage...

Significance Flexible polymer dielectrics operable under not only electrical but also thermal extremes are desired for high-power-density and high-payload-efficiency electrification. Unfortunately, state-of-the-art high-temperature polymers exhibit largely reduced electrical energy storage performance, as traditionally their bandgaps are inversely...

Current wearable technology is often bulky and restrictive to fluid movement. This work details a single-layer, hydrophobic, printed electrochromic textile that switches wirelessly from red to blue with a switching speed ≈30 s. Using a hole-through fabrication method, the flexible devices offer aesthetics to the display by concealing all electronic...

Polymer dielectrics essentially revolutionized the electrical power system, pervasively used in nearly all the key electronic and electrical devices, due mainly to their suitably large bandgaps. However, insufficient attention has been paid to the bandgap in the design of new polymer dielectrics for high temperatures. In this paper, we present a un...

Flexible Nanogenerators In article number 2103161, Yang Cao and co-workers describe a new all-organic flexible nanogenerator with expanded polytetrafluoroethylene (ePTFE)-based ferroelectret and fabric-based electrodes. Like a charge-spring of three deformable dipoles, the outer electret-plus-electrode double layers form active device layers with d...

Due to their electrically polarized air-filled internal pores, optimized ferroelectrets exhibit a remarkable piezoelectric response, making them suitable for energy harvesting. Expanded polytetrafluoroethylene (ePTFE) ferroelectret films are laminated with two fluorinated-ethylene-propylene (FEP) copolymer films and internally polarized by corona d...

The dielectric constant (ϵ) is a critical parameter utilized in the design of polymeric dielectrics for energy storage capacitors, microelectronic devices, and high-voltage insulations. However, agile discovery of polymer dielectrics with desirable ϵ remains a challenge, especially for high-energy, high-temperature applications. To aid accelerated...

High‐performance flexible loudspeakers have the potential to revolutionize the future of flexible/wearable electronics by providing this long‐sought function. Here, a novel method is developed to produce large‐area, flexible, and transparent piezoelectric loudspeakers, where both piezoelectric lead zirconate titanate (PZT) nanoparticles and graphen...

Flexible dielectrics operable under simultaneous electric and thermal extremes are critical to advanced electronics for ultrahigh densities and/or harsh conditions. However, conventional high‐performance polymer dielectrics generally have conjugated aromatic backbones, leading to limited bandgaps and hence high conduction loss and poor energy densi...

A molecular engineering principle in which repeat units of fairly rigid fused bicyclic structure and alkenes, separated by freely rotating single bonds, is proposed by Gregory A. Sotzing, Yang Cao, and co‐workers in article number 2000499 for energy storage at elevated temperatures. The piston‐like crankshaft structure endows the system with a larg...

Enhancing dipole polarization has been demonstrated as an effective approach to increase the dielectric constant of polymer dielectrics and thus to improve their discharged energy density for energy storage applications in electrical power and electronic systems. However, further optimization to get a higher dielectric constant and lower polarizati...

Dielectric flexible film with high dielectric constant and low dielectric loss has received increased demands over the past decade due to its wide range of applicability in modern electronics like flexible circuit, hybrid vehicle, pulsed power systems. Novel Sn-polyester based organometalllic pDMTDMG polymer is processed with organic polyimide base...

Advances in materials can be achieved once we understand their property well. In this study, a series of zinc and cadmium aliphatic polyesters with varying numbers of methylene spacer(s), 1 to 8, are synthesized and characterized to understand their features, which control their dielectric properties. The rational co-design of these materials is ad...

The real-time mechano-optical behavior of Polyimide 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) 1,6-diaminohexane (DAH) [PI(BTDA-DAH)] films during uniaxial deformation was investigated in the glassy and rubbery states as a function of temperature and stretch rate to understand the stretching characteristics of the polymer and elucida...

Conductive textiles with exceptional electrical properties have been prepared by coating the conjugated polymer, poly(3,4-ethylenedioxyphiophene)-polystyrenesulfonate(PEDOT-PSS), on polyethylene terephthalate (PET) nonwoven fabrics. Phase segregation from covalent bond formation to surface silica particles generates PEDOT-PSS coated textiles that h...

In order to interface power sources with any electrical load, energy storage and conversion are important components. The ability to store electrical energy is essential in many applications. Dielectric materials with high electric energy density are essential components in modern power electronics such as pulsed power systems and switched mode pow...

The attractiveness of electrochromic devices (ECDs) is the possibility of making flexible devices and displays with more potential applications than non-flexible displays. These flexible ECDs segue into the next generation of ECDs: electrochromic fabric devices (EFDs). Ideally, EFDs would provide high contrast, sharpness of colours and also a varie...

Large dielectric constant and band gap are essential for insulating materials used in applications such as capacitors, transistors and photovoltaics. Of the most common polymers utilized for these applications, polyvinyldiene fluoride (PVDF) offers a good balance between dielectric constant, >10, and band gap, 6 eV, but suffers from being a ferroel...

Herein, we present a versatile way to increase the photopic contrast of electrochromic devices (ECDs), approximately 14%, through the use of binary mixtures of propylene carbonate, diethyl carbonate, and ethylene carbonate that serve the role as plasticizers in the gel electrolyte. The binary plasticizer mixture changed the physical properties of t...

Conductive fabrics are central to smart textiles, a concept that has been gaining attention for applications such as wearable electronics or biosensors. However, current approaches for creating electrically conductive fabrics struggle with issues ranging from low conductivity to skin irritation. The use of graphitic carbon has been investigated as...

Herein, the synthesis and characterization of a series of Diels–Alder (DA) polymers made with various bis-furans and 1,3-bis(maleimide)propane are described. Due to the fact that these syntheses produce no byproducts inherent to their mechanism, as well as the relative ease at which highly functionalized monomers can be made, these polymers are ide...

An electrochromic fiber or fabric is disclosed. The fiber or fabric includes a flexible, electrically conductive fiber, wherein the fiber comprises a non-electrically conductive organic polymer coated with an electrically conductive polymer; and; a layer comprising an electrochromic material disposed on and surrounding the flexible, electrically co...

High-dielectric constant materials are critical for numerous applications such as photovoltaics, photonics, transistors, and capacitors. There are numerous polymers used as dielectric layers in these applications but can suffer from having a low dielectric constant, small band gap, or ferroelectricity. Here, the structure-property relationship of v...

adma.201404162 ferroelectricity but with lower dielectric constants as the copoly-mers formed are random in nature. [ 5,6 ] A second method to increase the permittivity of polymers is through the addition of high-dielectric-constant nanoparticles, such as barium titanate. [ 7 ] However, an effective increase of the dielectric constant is not observ...

Correction for ‘Orthogonal alignment of DNA using hexafluoroisopropanol as solvent for film castings’ by Donna Marie D. Mamangun et al., RSC Adv., 2014, 4, 39798–39801.

Flexible display devices consisting of electrochromic polymers, which can be easily manufactured in a method exhibiting low cost and low waste, and covering large areas, have yet to be realized. Electrochromic devices traditionally have been fabricated by depositing an electrochromic polymer onto the electrode via electrodeposition, which can be a...

Supplementary information available for this article at http://www.nature.com/ncomms/2014/140917/ncomms5845/suppinfo/ncomms5845_S1.html

To date, trial and error strategies guided by intuition have dominated the identification of materials suitable for a specific application. We are entering a data-rich, modelling-driven era where such Edisonian approaches are gradually being replaced by rational strategies, which couple predictions from advanced computational screening with targete...

Substituted selenophene monomers, and polymers and copolymers having units derived from a substituted selenophene are disclosed. Also provided are methods of making and using the same.

Herein, we describe the synthesis and characterization of polymers formed by the Diels-Alder (DA) reaction between various difurans and divinylsulfone, and evaluate their dielectric properties. These syntheses were planned with computational support a priori in the form of HOMO/LUMO calculations for the dienes and dienophiles, with the calculated D...

Stretchable electrochromic devices are disclosed including a stretchable electrochromic substrate; and a stretchable and transparent polymeric electrolyte coating or impregnating the stretchable electrochromic substrate. The stretchable electrochromic devices can find utility in the preparation of wearable electronic garments. Other devices using a...

Herein, we present a facile, one-step method to color tune electrochromic devices (ECDs) that switch between two neutral colors via in situ electrochemical polymerization of electroactive monomers in the presence of a small molecule organic yellow dye using all commercially available materials. These devices exhibited photopic contrasts of ca. 30%...

Development of new dielectric materials is of great importance for a large range of applications for modern electronics and electrical power systems. The state-of-art polymer dielectric is biaxially oriented polypropylene (BOPP) films having a maximum energy density of 5 J/cm(3) and a high breakdown field of 700 MV/m, but with limited dielectric co...

The establishment of a relationship between device performance parameters such as switch speed and photopic contrast with device composition, electrochromic polymer thickness, and gel electrolyte composition is reported here for a versatile one-step preparation method of relatively large area, 105 cm2, solid-state electrochromic devices. The electr...

Electrochromic fabric devices represent a further extension to the plethora of available literature on conductive fabrics. This article contains a brief overview of electrochromic devices, electrochromic polymers, conductive materials, conductive fabrics, and electrochromic fabric devices. A tabulated list of the perceived colour of a number of ele...

Utilizing our in situ method for the one step assembly of single-layer electrochromic devices (ECDs) with a 3,4-propylenedioxythiophene (ProDOT) acrylate derivative, long-term stability was achieved. By coupling the electroactive monomer to the cross-linkable polymer matrix, preparation of the electrochromic ProDOT polymer can occur followed by UV...

Conductive poly(3,4-ethylenedioxythiophene):sulfonated polyimide (PEDOT: SPI) nanoscale thin films were successfully developed by addition of anionic surfactant and poly(vinyl alcohol) (PVA) for potential application in electronic devices. In this work, sodium dodecyl sulfate (SDS) surfactant was introduced into PEDOT:SPI aqueous suspensions to imp...

Diffusion of two monomers and their oxidative copolymerization inside of a solid-state gel electrolyte is utilized as a method to match the monomer feed ratio to a color resulting from a conjugated copolymer having a single absorption in the visible region. Here, a combination of two monomers is used to generate a solid-state electrochromic device...

Conductive poly(3,4-ethylenedioxythiophene):sulfonated polyimide (PEDOT:SPI) films were successfully developed by decreasing the particle size along with the addition of anionic surfactant leading to potential applications in electronic devices. By varying the mixing system (magnetic bar at 1000 rpm, mechanical at 1000 rpm and mechanical at 4000 rp...

Most polyolefins that are used for dielectric materials exhibit a low dielectric constant and operating temperatures up to 70°C. Polyimides offer a means to a higher dielectric constant material by the introduction of a polar group in the polymer backbone and are thermally stable at temperatures exceeding 250°C. A common dianhydride, pyromellitic d...

Herein, the addition of an anionic surfactant, sodium dodecyl sulfonate (SDS), during the template polymerization of conducting polymers to improve the nano-thin films properties was investigated. In order to compare the effects, three methods of addition SOS were demonstrated: addition of SDS during template polymerization, addition after template...

In this work, the integration of the useful concepts of polymer blending and doping agent to simultaneously improve various properties of poly(3,4-ethylene dioxy thiophene) poly(styrene sulfonate) (PEDOT:PSS) nano-thin films was shown. According to the polymer-blending concept, insulating poly(vinyl alcohol) (PVA) has a good deal of potential to be...

Herein we report the synthesis of a new class of processable siloxane precursor polymers consisting of aromatic groups and flexible siloxane linkages and their conversions to green and blue electrochromic polymers in the solid state. 3,4-Ethylenedioxythiophene (EDOT), 2,2′-bis(3,4-ethylenedioxythiophene) (BiEDOT), and a donor–acceptor moiety 4,7-bi...

When designing polymeric capacitors, it is important to understand the structure-property relationship between chemical functionalities and dielectric properties to tailor materials for specific applications in terms of dielectric constant, dielectric loss, band gap, breakdown strength, etc. Herein, we report a clear structure-property relationship...

Poly(3,4‐ethylenedioxythiophene) (PEDOT) was polymerized using sulfonated poly(amic acid)s templates (SPAA1 and SPAA2) by batch operation. The new method was invented to enhance conductivities (ca. 100 ‐ to 2000‐fold) and with less reaction time from previous work (7 days vs. 3 days). Moreover, to increase the conductivity, many dopants were introd...

When designing polymeric capacitors, it is important to understand the structureeproperty relationship between chemical functionalities and dielectric properties to tailor materials for specific applications in terms of dielectric constant, dielectric loss, band gap, breakdown strength, etc. Herein, we report a clear structureeproperty relationship...

We demonstrate a facile controlling of the optical and colorimetric properties of a donor-acceptor conjugated polymer simply by varying the mix ratio of two precursors in a precursor blend. The conversion of a precursor blend results in an entirely new donor-acceptor polymer, distinct from the conjugated polymer of each precursor. Careful optimizat...

Polyimide graft polyaniline was successfully synthesized by a three step reaction. First, the polyimide backbone was prepared by reacting 4,4′-hexafluoroisopropylidene diphthalic anhydride (6FDA), 3,3′-dihydroxybenzidine (DHBD) with 4,4′-oxydianiline (ODA). Then, the hydroxyl groups of DHBD were reacted with 3-bromoaniline to link the polyimide bac...

Disclosed herein is a facile process for the formation of conjugated polymers inside or outside assembled solid-state devices. One process generally involves applying a voltage to a device comprising at least two electrodes, a combination of an electrolyte composition and a electroactive monomer disposed between the electrodes, and a potential sour...

An enhanced dielectric permittivity of polyethylene and related polymers, while not overly sacrificing their excellent insulating properties, is highly desirable for various electrical energy storage applications. In this computational study, we use density functional theory (DFT) in combination with modified group additivity based high throughput...

Significant modifications have been made in the processing techniques developed to transform purified, marine-based deoxyribonucleic acid (DNA) into a biopolymer suitable for optical and electronic device fabrication. This technique employs a modified soxhlet-dialysis rinsing process to completely remove excess ionic contaminants from the DNA biopo...

Aside from salmon DNA, other DNA sources were explored namely, herring and onion, to prepare DNAsurfactant complex, which will be used as a template for dyes undergoing Forster Resonance Energy Transfer (FRET). Also, salmon DNA of low and high molecular weight were compared. This study aims to assess the effect of using different DNA sources and mo...

Herein, sulfonated polyimides are utilized as a template for the polymerization of pyrrole (Py), aniline (ANi) and 3,4-ethylenedioxythiophene (EDOT) in order to produce their corresponding conductive polymers as stable processable aqueous dispersions. With polyimides having high thermal stabilities, the use of sulfonated polyimides (SPI) as templat...

We study the effect on the microwave S-parameters of adding a conjugated polymer layer to a deoxyribonucleic acid-based (DNA-based) biopolymer within a variable capacitor (varactor) using a capacitive test structure. The conjugated polymer we are using in this work is poly(3-hexylthiophene-2,5-diyl) (P3HT) and the DNA-based biopolymer is DNA-CTMA....

Herein we demonstrated the preparation of 3,4-ethylenedioxythiophene (EDOT) containing polynorbornylene brushes on Au surfaces via surface-initiated ring-opening metathesis polymerization (SI-ROMP). Using solid-state oxidative crosslinking technique, these polymer brushes were electrochemically converted to conjugated polymer networks. Grazing-angl...

An efficient cascade FRET was realized in solid state DNA-CTMA thin films using a three chromophore system without any covalent attachments. The extent of energy transfer from Cm102 to SRh was studied and found to improve eight-fold using the bridging dye Pm567.

The polymer PEDOT+ mediates a Nazarov-like cyclization of dienones, in an heterogeneous system and in hydrocarbon solvents. The polymer-mediated reactions show clear differences in product formation when compared to the same reaction with tosic acid, or when compared to reports in the literature. Comparable or improved yields are observed, as well...

Herein we present a simple and elegant method for the creation of solid-state conjugated polymer devices. Their electrochromic properties were fully explored in this study, but one could envision the extension of this method to displays, solar cells, OLEDs, transistors, or many other applications. We prepared conductive polymer composites or blends...

A transetherification procedure for 1,3-disubstitution using tert-butyl, hexyl, isopropyl, and methyl groups was investigated. It resulted in 1,3-di-t-butylProDOT (13ProDOT-TB2), 1,3-dihexylProDOT (13ProDOT-Hex2), 1,3-diisopropylProDOT (13ProDOT-IP2), and 1,3-dimethyl-ProDOT (13ProDOT-Me2), respectively. The electrochromic polymer, P13ProDOT-TB2, w...

The polymer PEDOT(+) (1 or 2) mediates a cyclodehydration reaction with alditols 3, 5, 7, 9, in hydrocarbon solvents, to give cyclic ethers 4, 6, 8, or 10, respectively, in high yield with a trivial isolation protocol. Polymers 1 or 2 also mediate the cyclodehydration of ketohexoses such as d-fructose, but not aldohexoses, to the important industri...

The colour of electrochromic fabric, and its colour transitions, was explored on the basis of variations in underlying fabric colour. A complete understanding of this phenomenon is essential for the fabric’s use in full-colour wearable displays or other applications. Previous work in this area utilised only white-coloured starting materials. Herein...

Electrochemical detection combined with nanostructured sensor surfaces offers potentially low-cost, high-throughput solutions for detection of clinically significant proteins. Inkjet printing offers an inexpensive non-contact fabrication method for microelectronics that is easily adapted for incorporating into protein immunosensor devices. Herein w...