分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-08
摘要: Highly flexible and transparent film heaters (TFHs) with superior mechanical and thermal stability were fabricated by embedding silver nanowires (AgNWs) into transparent polyimide (PI) films using a solution coating method. The fabricated AgNW/PI hybrid TFHs exhibited higher heating temperatures ($96 C) with lower input voltage ($6 V), shorter response time (T < 40 s), and lower power consumption (160.6 C cm2 W 1) than ITO/FTO heaters, as well as stability after repeated use. The AgNW/PI hybrid TFHs also showed excellent resistance to bending. After undergoing outer bending for a 1000 times, the change of sheet resistance was less than 18%. The effective embedment of the AgNW network in the surface of the transparent PI film not only decreased the surface roughness (Rrms < 1 nm) but also enhanced the resistance against oxidation and moisture. Potential applications of the AgNW/PI TFHs in window defogging and thermochromics are demonstrated.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Two series of poly(ester imide)s derived from bis(trimellitic acid anhydride) phenyl ester (TAHQ) and bis[(3,4- dicarboxylic anhydride) phenyl] terephthalate (PAHP), as well as poly(ether imide)s based on hydroquinone diphthalic anhydride (HQDPA), were synthesized with aromatic diamines via solution polycondensation. These polyimide films were transparent with an ultraviolet-visible absorption cut-off wavelength below 375 nm, and with tensile strengths of 42.0–83.8 MPa, tensile moduli of 2.5–4.7 GPa and elongations at break of 2.1–5.4%. Compared with the poly(ether imide)s, the poly(ester imide)s showed higher glass transition temperatures (Tg), lower water absorption (WA) and lower temperature of 5% weight loss (Td5%). Moreover, the poly(ester imide)s derived from PAHP with a low electron affinity of 2.04 eV by theoretical calculation achieved better transparency, lower WA and slightly lower Tg than the corresponding TAHQ- based poly(ester imide)s.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Flexible transparent conductive films (TCFs) are used in a variety of optoelectronic devices. However, their use is limited due to poor thermostability. We report hybrid TCFs incorporation in both aluminum-doped zinc oxide (AZO) and silver nanowires (AgNWs). The layered AZO/ AgNWs/AZO structure was deposited onto a transparent polyimide (PI) substrate and displayed excellent thermo- stability. When heated to 250 °C for 1 h, the change in resistivity (Rc) was less than 10% (Rc of pure AgNW film > 500) while retaining good photoelectric properties (Rsh = 8.6 Ohm/sq and T = 74.4%). Layering the AgNW network between AZO films decreased the surface roughness (Rrms < 8 nm) and enhances the mechanical flexibility of the hybrid films. The combination of these characteristics makes the hybrid film an excellent candidate for substrates of novel flexible optoelectronic devices which require high-temperature processing.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: To investigate the asymmetric effect of the naphthalimide moiety on the thermal, mechanical, optical properties and water uptake of polyimides (PIs), two novel asymmetric diamines, 4-(4-aminophenoxy)- N-amino-1,8-naphthalimide 3 and 4-(4-aminophenoxy)-N-(4-aminophenyl)-1,8-naphthalimide 4 were synthesized. Two series of PIs 5b–e and 6a–e were prepared from diamines 3 and 4 by solution polymerization method, respectively. The resulting polyimides demonstrated good solubility, high glass transition temperature (Tg) of 311–421 C and good thermal stability based on the 5% weight loss temperature (T5%) of 435–563 C in nitrogen. These PIs also exhibited good mechanical properties with tensile strengths of 107.3–172.2 MPa, tensile moduli of 2.8–4.9 GPa, and elongations at break of 2.9–9.1%. The water uptake of PIs was in the range of 0.33–1.96%. The polyimides displayed UV-vis absorption maxima and an intense fluorescent intensity in the range of 361–371 and 480–700 nm, respectively.
提交时间: 2017-05-02
摘要: Polyimide/reduced graphene oxide [PI/r-GO] core-shell structured microspheres were fabricated by in situ reduction of graphene oxide [GO], which was coated on the surface of PI microspheres via hydrogen bonding and pi-pi stacking interaction. The highly o
提交时间: 2017-05-02
摘要: A series of isomeric poly[thioether ether imide]s [PTEIs] containing both thioether and ether linkages were prepared by aromatic nucleophilic substitution reaction of isomeric bis[chlorophthalimide]s [BCPIs] with bis[4-mercaptophenyl] ether [BMPE]. The in