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Ion Transport in Pendant and Backbone Polymerized Ionic Liquids
Get PDFPolymerized ionic liquids (PILs) are single-ion conductors in which one of the ionic species is tethered to the polymer chain while the other is free to be transported. The ionic species can either be directly incorporated into the polymeric backbone (backbone PILs) or placed as pendant groups to the chain (pendant PILs). Here, we examined the morphology, conductivity, and rheology of imidazolium-based pendant and backbone PILs. We found that pendant PILs yielded higher ionic conductivity when scaled to Tg, but backbone PILs exhibited higher ionic conductivity on an absolute temperature scale, likely because of differences in the Tgs of the two systems. We also found that ion transport for backbone PILs was coupled to the segmental dynamics below Tg, where the decoupling of ionic conductivity from segmental relaxation was observed for pendant PILs. The results of this study will help the community to better understand the role of the PIL structure on conductivity to work toward the ultimate goal of designing high-performance solid polymer electrolytes.journal articl
Orange Organic Long-persistent Luminescence from an Electron Donor/Acceptor Binary System
Get PDFOrganic long-persistent luminescence (LPL) materials can overcome the disadvantages of inorganic LPL materials in terms of element sustainability, processability, and color tunability. However, all published electron donor/acceptor binary organic LPL systems show green emission. Here, we report an organic LPL system consisting of N,N,N',N'-tetrakis(p-diisobutylaminophenyl)-p-phenylenediamine (TBAPD) as a donor dopant and 2,8-bis(diphenylphosphoryl)dibenzo[b,d]thiophene (PPT) as an acceptor host. The TBAPD/PPT film exhibits orange photoluminescence (CIEx, CIEy = 0.49, 0.49) and LPL (CIEx, CIEy = 0.51, 0.48).journal articl
Surface Termination-Dependent Nanotribological Properties of Single-Crystal MAPbBr3 Surfaces
Get PDFAtomistic characterization of surface termination and the corresponding mechanical properties of single-crystal methylammonium lead tribromide (MAPbBr3) are performed using combined atomic force microscopy (AFM) measurements and density functional theory (DFT) calculations. A clean MAPbBr3 surface is obtained by in situ cleavage in ultrahigh vacuum at room temperature, and the subsequent AFM measurements of the as-cleaved MAPbBr3 exhibit the coexistence of two different surface terrace types with step height differences corresponding to about half the thickness of a PbI6 octahedron layer. Concurrent friction force microscopy measurements show that the two surfaces result in two distinct friction values. Based on DFT calculations, we attribute the higher-friction and lower-friction surfaces to MABr-terminated flat and PbBr2-terminated vacant surface terminations, respectively. The calculated electronic band structures of the various MABr- and PbBr2-terminated surfaces show that the midgap states are absent, revealing the defect-tolerant nature of the ideal single-crystal MAPbBr3 surfaces.journal articl
Coupled density-spin Bose–Einstein condensates dynamics and collapse in systems with quintic nonlinearity
Get PDFWe investigate the effects of spin-orbit coupling and Zeeman splitting on the coupled density-spin dynamics and collapse of the Bose–Einstein condensate driven by the quintic self-attraction in the same- and cross-spin channels. The characteristic feature of the collapse is the decrease in the width as given by the participation ratio of the density rather than by the expectation values of the coordinate. Qualitative arguments and numerical simulations reveal the existence of a critical spin-orbit coupling strength which either prohibits or leads to the collapse, and its dependence on other parameters, such as the condensate’s norm, spin-dependent nonlinear coupling, and the Zeeman splitting. The entire nonlinear dynamics critically depends on the initial spin sate.journal articl
Dynamic control of neurochemical release with ultrasonically-sensitive nanoshell-tethered liposomes
Get PDFThe unique surface plasmon resonance of hollow gold nanoshells can be used to achieve drug release from liposomes upon laser stimulation, and adapted to mimic the intricate dynamics of neurotransmission ex vivo in brain preparations. However, to induce a physiological response in vivo requires the degree of temporal precision afforded by laser stimulation, but with a greater depth of penetration through tissue. Here we report that the attachment of hollow gold nanoshells to the surface of robust liposomes results in a construct that is highly sensitive to ultrasonic stimulation. The resulting construct can be remotely triggered by low intensity, therapeutic ultrasound. To our knowledge, this is the first example of nanoparticle-liposome system that can be activated by both laser and acoustic stimulation. The system is capable of encapsulating the neurochemical dopamine, and repeatedly releasing small amounts on-demand in a circulating environment, allowing for precise spatiotemporal control over the release profile.journal articl
Ancestral diet transgenerationally influences offspring in a parent-of-origin and sex-specific manner
Get PDFParent-of-origin effects, whereby specific phenotypes are differentially inherited paternally or maternally, provide useful clues to better understand transgenerational effect transmission. Ancestral diet influences offspring phenotypes, including body composition and fitness. However, the specific role that mothers and fathers play in the transmission of altered phenotypes to male and female offspring remains unclear. We investigated the influence of the parent-of-origin's diet on adult progeny phenotypes and reproductive output for three generations in fruit flies (Drosophila melanogaster). Males and females reared on a control diet were exposed to the control diet or one of two altered (no- or high-) sugar treatment diets for a single generation. Flies from one of the two altered diet treatments were then mated to control flies in a full-factorial design to produce F1 offspring and kept on control media for each following generation. We found parent-of-origin (triglyceride) and non-parent-of-origin (sugar) body composition effects, which were transgenerational and sex-specific. Additionally, we observed a negative correlation between intergenerational maternal reproductive output and triglyceride levels, suggesting that ancestral diet may affect fitness. This work demonstrates that ancestral diet can transmit altered phenotypes in a parent-of-origin and sex-specific manner and highlights that mechanisms regulating such transmission have been greatly overlooked.
This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.journal articl
Graded-index optical fiber emulator of an interacting three-atom system: illumination control of particle statistics and classical non-separability
Get PDFWe show that a system of three trapped ultracold and strongly interacting atoms in one-dimension can be emulated using an optical fiber with a graded-index profile and thin metallic slabs. While the wave-nature of single quantum particles leads to direct and well known analogies with classical optics, for interacting many-particle systems with unrestricted statistics such analoga are not straightforward. Here we study the symmetries present in the fiber eigenstates by using discrete group theory and show that, by spatially modulating the incident field, one can select the atomic statistics, i.e., emulate a system of three bosons, fermions or two bosons or fermions plus an additional distinguishable particle. We also show that the optical system is able to produce classical non-separability resembling that found in the analogous atomic system.journal articl
Reduction of lead leakage from damaged lead halide perovskite solar modules using self-healing polymer-based encapsulation
Get PDFIn recent years, the major factors that determine commercialization of perovskite photovoltaic technology have been shifting from solar cell performance to stability, reproducibility, device upscaling and the prevention of lead (Pb) leakage from the module over the device service life. Here we simulate a realistic scenario in which perovskite modules with different encapsulation methods are mechanically damaged by a hail impact (modified FM 44787 standard) and quantitatively measure the Pb leakage rates under a variety of weather conditions. We demonstrate that the encapsulation method based on an epoxy resin reduces the Pb leakage rate by a factor of 375 compared with the encapsulation method based on a glass cover with an ultraviolet-cured resin at the module edges. The greater Pb leakage reduction of the epoxy resin encapsulation is associated with its optimal self-healing characteristics under the operating conditions and with its increased mechanical strength. These findings strongly suggest that perovskite photovoltaic products can be deployed with minimal Pb leakage if appropriate encapsulation is employed.journal articl