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Polymer-Gated Transistors with Only One Solution-Processed, Single Crystalline Organic Microwire for Light and Oxygen Detection
No full textOrganicsemiconductors employed in single crystalline form haveseveral advantages over polycrystalline films, such as higher chargecarrier mobility and better environmental stability. Herein, we reportthe fabrication and characterization of a solution-processed microsizedsingle-crystalline organic wire of n-type N,N '-dipentyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C-5). The crystal was appliedas an active layer in polymer-gated organic field-effect transistors(OFETs) and organic complementary inverter circuits. The single crystaiilinenature of PTCDI-C-5 wires were characterized using two-dimensionalgrazing incidence wide-angle X-ray diffraction (2D-GIXD) and polarizedoptical microscopy. OFETs with the PTCDI-C-5 crystals exhibitedhigh n-type performance and air stability under ambientconditions. To investigate the electrical properties of the single-crystallinePTCDI-C-5 wire more precisely, OFETs with only one PTCDI-C-5 microwire in the channel were fabricated, and clear n-type characteristics with satisfactory saturation behaviorwere observed. The device with only one crystal wire exhibited characteristicswith significantly lower variation compared to the multicrystal devices,which shows that the density of crystal wires is a critical factorin precisely investigating device performance. The devices exhibiteda reversible threshold voltage shift under vacuum and oxygen conditions,without changing the charge carrier mobility. Light-sensitive characteristicswere also observed. Additionally, this solution-processed, highlycrystalline organic semiconductor can be used in high-performanceorganic electronic circuits as well as in gas or light sensors
Achieving volatile potassium promoted ammonia synthesis via mechanochemistry
No full textPotassium oxide is used as a promotor in industrial ammonia synthesis, although metallic potassium is better in theory. Here, the authors demonstrate metallic potassium, an unstable metal that easily volatilizes at high temperature, can be used as a promotor for ammonia synthesis. Potassium oxide (K2O) is used as a promotor in industrial ammonia synthesis, although metallic potassium (K) is better in theory. The reason K2O is used is because metallic K, which volatilizes around 400 degrees C, separates from the catalyst in the harsh ammonia synthesis conditions of the Haber-Bosch process. To maximize the efficiency of ammonia synthesis, using metallic K with low temperature reaction below 400 degrees C is prerequisite. Here, we synthesize ammonia using metallic K and Fe as a catalyst via mechanochemical process near ambient conditions (45 degrees C, 1 bar). The final ammonia concentration reaches as high as 94.5 vol%, which was extraordinarily higher than that of the Haber-Bosch process (25.0 vol%, 450 degrees C, 200 bar) and our previous work (82.5 vol%, 45 degrees C, 1 bar)
Mitigating self-desiccation of cement composites via cellulose microfibers: Evidence of the microscopic behavior
No full textWater-saturated cellulose microfibers (CMFs) incorporated into fresh cement composites can mitigate microcracking induced by self-desiccation during drying. To understand the mechanism underlying the water supply via CMFs to the pore systems, this study utilized a nonlinear impact resonance acoustic spectroscopy (NIRAS) technique. The hysteresis nonlinearity parameter (????) from the NIRAS was used to quantify the microstructural changes in three different specimens (0, 0.3, and 1% dosage of CMFs). Computed tomography (CT) tests and mass tracking were conducted to obtain more insights into the mitigation of self-desiccation. The results show a remarkable reduction in ??, confirming the mitigation of microcracking formation over time. Furthermore, the trend of ?? was consistent with the pore size distribution estimated by the CT test, which provides quantitative evidence to support the mitigation of self-desiccation promoted by CMFs. We envision that these findings can be used as guidelines for enhancing the durability of cement composites facilitated by CMFs
Smooth, Chemically Altered Nucleating Platform for Abrupt Performance Enhancement of Ultrathin Cu-Layer-Based Transparent Electrodes
No full textRapid advances in flexible optoelectronic devices necessitatetheconcomitant development of high-performance, cost-efficient, and flexibletransparent conductive electrodes (TCEs). This Letter reports an abruptenhancement in the optoelectronic characteristics of ultrathin Cu-layer-basedTCEs via Ar+-mediated modulation of the chemical and physicalstates of a ZnO support surface. This approach strongly regulatesthe growth mode for the subsequently deposited Cu layer, in additionto marked alteration to the ZnO/Cu interface states, resulting inexceptional TCE performance in the form of ZnO/Cu/ZnO TCEs. The resultantHaacke figure of merit (T (10)/R (s) ) of 0.063 & omega;(-1), 53% greater than that of the unaltered, otherwise identical structure,corresponds to a record-high value for Cu-layer-based TCEs. Moreover,the enhanced TCE performance in this approach is shown to be highlysustainable under severe simultaneous loadings of electrical, thermal,and mechanical stresses
Tailoring Pressure Sensitive Adhesives with H6XDI-PEG Diacrylate for Strong Adhesive Strength and Rapid Strain Recovery
No full textThe development of flexible electronic technology has led to convenient devices, including foldable displays, wearable, e-skin, and medical devices, increasing the need for flexible adhesives that can quickly recover their shape while connecting the components of the device. Conventional pressure sensitive adhesives (PSAs) can improve recoverability via crosslinking, but often have poor adhesive strength. In this study, new types of urethane-based crosslinkers are synthesized using m-xylylene diisocyanate (XDI) or 1,3-bis(isocyanatomethyl)cyclohexane (H6XDI) as a hard segment, and poly(ethylene glycol) (PEG) group as a soft segment. The PSA with the synthesized H6XDI-PEG diacrylate (HPD) demonstrates a significantly improved recoverability compared to XDI-PEG diacrylate and a conventional crosslinker 1,6-hexanediol diacrylate (HDDA) while maintaining high adhesion strength (& AP;25.5 N 25 mm(-1)). The excellent recovery property of the PSA crosslinked with HPD is further confirmed by 100k folding tests and 10k multi-directional stretching tests exhibiting high folding and stretching stability. PSA with HPD also shows high optical transmittance (> 90%) even after 20% straining, suggesting its applicability in fields that simultaneously require high flexibility, recoverability, and optical clarity such as foldable displays
Inference to the best explanation, naturalism, and theism
No full textDe Ray argues that relying on inference to the best explanation (IBE) requires the metaphysical belief that most phenomena have explanations. I object that instead the metaphysical belief requires the use of IBE. De Ray uses IBE himself to establish theism that God is the cause of the metaphysical belief, and thus he has the burden of establishing the metaphysical belief independently of using IBE. Naturalism that the world is the cause of the metaphysical belief is preferable to theism, contrary to what de Ray thinks
