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Mobility is an important parameter to estimate the performance of organic thin‐film transistors, one of the key factors affecting the mobility is the first several semiconductors molecular layers near the insulator surface. A strategy is proposed to introduce aromatic‐rings in the gate insulating layer to modulate the growth of pentacene, thus a series of aryl group containing polymers by reversible‐addition‐fragmentation chain‐transfer polymerization is synthesized for the preparation of organic thin‐film transistor insulators. The semiconductor layer is evaporated on the polymer insulators at room temperature. As the inducing function of the aromatic ring, greater weak interactions between dielectric materials and semiconductors by simulation, which makes the initial pentacene layer weak epitaxial growth, therefore pentacene could form better morphology, especially larger crystal domains and uniform thin‐film continuity. The results show that precision design and synthesis of polymer insulator layers provide new methods to achieve high performance of organic thin‐film transistors with easier fabricating process. [ABSTRACT FROM AUTHOR]

In this study, polyurethane dimethacrylate (PUDMA) was synthetized from different components and incorporated into a direct resin composite restoration system with the aim to buffer tooth–resin interfacial stresses and maintain the marginal adaptation. The tensile strength, elongation at fracture (ε), and thermal stability of the PUDMA layer were characterized, showing a tensile strength of 22 MPa, an ε of 112%, and a thermal decomposition temperature of about 282°C. In addition, the degree of conversion, water sorption/solubility, hydrophobicity, microtensile bond strength (μTBS), marginal leakage, and cytotoxicity in vitro were evaluated for the PUDMA layer. The data were analyzed using one‐way ANOVA, except for leakage depths (which were analyzed using the Wilcoxon paired‐rank test). The level of significance was set at 0.05. Compared with dental adhesives, PUDMA displayed a higher degree of conversion, lower water sorption/solubility, and improved hydrophobicity and biocompatibility in vitro. After thermocycling, the μTBS of the restoration system containing PUDMA had increased compared with the μTBS at 24 h. Restorations containing PUDMA showed lower leakage depths than those which did not contain PUDMA. In conclusion, because of its hydrophobic and elastic nature, the PUDMA layer, when used as an intermediate between tooth and resin restoratives, may buffer interfacial stresses, improve the stability and durability of the bonding interface, and reduce microleakage. [ABSTRACT FROM AUTHOR]

Organic field‐effect transistor‐ (OFET‐) based nonvolatile memories (NVMs) are becoming more important as a core component in flexible and wearable electronics. New polymer materials containing abundant hydroxyl groups are synthesized and employed as the functional gate dielectric for OFET‐NVM devices. The dependence of the memory performances on the hydroxyl content of the polymers is investigated. A variety of gate dielectric structures are proposed to verify that the memory mechanism originates from the reversible remnant polarization of hydroxyl groups in the polymers and to improve the retention capability of the OFET‐NVM devices by preventing the charge trapping in the polymers at the reading state. As a result, good memory performance is achieved with a large memory window of 33.7 V and memory on/off ratio of 1.1 × 104 on average, long retention properties with clearly distinguishable binary states over 10 000 s, and reliable writing/erasing switching endurance over 200 cycles in the optimal OFET‐NVM device, in which the polymer with the most hydroxyl content is sandwiched by two insulator films. Good strategies for the design of the polarizable polymers as the functional gate dielectrics and for improvement of OFET‐NVM device performance are demonstrated. [ABSTRACT FROM AUTHOR]