Three O-fluoroazobenzene-based molecules were chosen as memory-active molecules: FAZO-1 with a D–A2–D symmetric structure, FAZO-2 with an A1–A2–A1 symmetric structure, and FAZO-3 with a D–A2–A1 asymmetric structure. Both FAZO-1 and FAZO-2 had a lower molecular polarity, whereas FAZO-3 had a higher polarity. The fabricated indium–tin oxide (ITO)/FAZO-1/Al (Au) and ITO/FAZO-2/Al (Au) memory devices both exhibited volatile static random access memory (SRAM) behavior, whereas the ITO/FAZO-3/Al (Au) device showed nonvolatile ternary write-once-read-many-times (WORM) behavior. It should be noted that the reproducibility of these devices was considerably high, which is significant for practical application in memory devices. In addition, the different memory performances of the three active materials were determined to be attributable to the stability of electric-field-induced charge-transfer complexes. Therefore, the switching memory behavior could be tuned by adjusting the molecular polarity.

A polymer containing aldehyde active groups (PVB) was synthesized by atom transfer radical polymerization (ATRP), acting as a polymer precursor to graft a functional moiety via nucleophilic addition reaction. DHI (2-(1,5-dimethyl-hexyl)-6-hydrazino-benzo[de]isoquinoline-1,3-dione) and NPH (nitrophenyl hydrazine) groups, which contain naphthalimides that act as narrow traps and nitro groups that act as deep traps, were anchored onto the PVB at different ratios. A series of graft polymers were obtained and named PVB-DHI, PVB-DHI₄-NPH, PVB-DHI-NPH₄, and PVB-NPH. The chemical composition of the polymers was analyzed by ¹H-NMR spectroscopy and X-ray photoelectron spectroscopy (XPS). Memory devices were prepared from the polymers, and I–V characteristics were measured to determine the performance. By adjusting the ratio of different electron acceptors (DHI and NPH) to 4:1, ternary memory behavior was achieved. The relationship between memory behavior of PVB-DHI_xNPH_y and acceptor groups as well as their conduction mechanism were studied in detail.

A one-phase synthesis of AuNPs-polymer nanocomposites using HAuCl₄ as the precursor is reported in this article. A flexible polymer, poly(2-(4-(di(1H-indol-3-yl)methyl)phenoxy) ethyl methacrylate) (PMPEM), containing indole groups on the side chain was utilized as both a reducing reagent and soft template in the system. The PMPEM-Au nanocomposites with three different sizes of AuNPs (25–50, 2, and 5 nm) were obtained just through choosing different solvents such as toluene, tetrahydrofuran (THF), and N,N-dimethylformamide, respectively. Nanocomposites including the size of 25–50 and 2 nm AuNPs showed strong NLO absorption and refraction behaviors. The nonlinear refractive index n₂ of PMPEM-Au nanocomposites prepared in toluene and THF were 9.35 × 10⁻¹¹ and 1.85 × 10⁻¹⁰ m²/W, third-order susceptibility χ⁽³⁾ were 2.55 × 10⁻¹¹ and 4.26 × 10⁻¹¹ esu, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The emission behavior of a new V-shaped organic fluorescent compound (p,p′-bis(2-aryl-1,3,4-oxadiazol-5-yl)diphenyl sulfone (OZA-SO), consisting of diethylamino (donor) and sulfone (acceptor) units, has been studied in various polar solvents and with different morphologies. As expected, there is the gradual transition from the locally excited state to the intramolecular charge-transfer (ICT) state with the increasing solvent polarity. The photoluminescence intensity of OZA-SO initially decreases with a low water fraction (f_w), owing to ICT effect, and then increases with a high f_w, owing to crystallization-induced emission enhancement. At the same time, the fluorescence lifetime of OZA-SO increases from 0.062 ns in dimethylformamide (DMF) to 5.80 ns in a solution containing 90 % water, and then to 7.49 ns in a solution containing 60 % water. Furthermore, the solid-state emission of OZA-SO can be tuned reversibly from green to yellow by fuming/grinding or fuming/heating owing to morphological changes. This color-switchable feature of OZA-SO may have potential applications in optical-recording and temperature-sensing materials.

A novel monomer bearing with pyrazoline chromophore, 3-(4-fluorophenyl)-1-phenyl-5-(4-(4-vinylbenzyloxy)phenyl-4,5-dihydro-1H-pyrazole (FStODO), was synthesized, and its atom transfer radical polymerization initiated by a tetrafunctional initiator, pentaerythritol tetrakis(2-bromoisobutyrate) (4Bri-Bu), was studied in detail and characterized by ¹H NMR, GPC, and TG-DSC. The solution, film luminescence of monomer, and its polymer were studied in detail. Compared with that of monomer, both luminescence emission intensity and quantum yield of star-shaped polymer PFStODO in DMF solution are decreased. However, the two-photon absorption (TPA) spectra in DMF solution measured by a femtosecond laser show an entirely different result that the maxima TPA cross-section value of polymer reaches to 203 GM, better than that of the monomer itself (13 GM). More interestingly, the film of polymer shows surprisingly white emission ranging from 400 to 700 nm assigned to the excimer formation. We attribute this formation of excimers to the ordered chromophore aggregates in film, which is further verified by X-ray diffraction. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011