Spectroscopic analyses on interaction of bovine serum albumin with novel spiro[cyclopropane-pyrrolizin].

The interaction between novel spiro[cyclopropane-pyrrolizin] (NSCP) and bovine serum albumin (BSA) was analyzed by fluorescence and ultraviolet-visible (UV-Vis) spectroscopy at 298 K, 304 K and 310 K under simulative physiological conditions. The results showed that NSCP can effectively quench the intrinsic fluorescence of BSA via static quenching. The binding constants, binding sites of NSCP with BSA were calculated. Hydrogen binds and van der Waals force played a major role in stabilizing the complex and the binding reaction were spontaneous. According to the Förster non-radiation energy transfer theory, the average binding distances between NSCP and BSA were obtained. What is more, the synchronous fluorescence spectra indicated that the conformation of BSA has been changed.

[Photoreactivation of Escherichia coli and Enterococcus faecalis in the secondary effluent disinfected by UV-TiO2].

Effects of photoreactivating light intensity (0-41 microW x cm(-2)) on photoreactivation of Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) in the secondary effluent after UV and UV-TiO2 disinfection were investigated. The results indicated that the disinfection efficiency of UV-TiO2 was much higher than that of UV disinfection. The photoreactivation rate of E. coli was much higher in UV disinfection than that in UV-TiO2 disinfection. Under high light intensity in UV-TiO2 disinfection, high resurrection rate can be induced. However, a higher resurrection rate can be introduced even under low light intensity in the UV disinfection. Meanwhile, UV-TiO2 disinfection had a strong inhibition effect on E. faecalis photoreactivation, when the light intensity was lower than 21 microW x cm(-2), three was no resurrection occurred on E. faecalis after 72 h resurrection irradiation, only under a strong photoreactivating light intensity, the resurrection rate of E. faecalis was observed.

Star-shaped D-A small molecules based on diketopyrrolopyrrole and triphenylamine for efficient solution-processed organic solar cells.

Three star-shaped D-A small molecules, (P-DPP)(3)TPA, (4-FP-DPP)(3)TPA, and (4-BuP-DPP)(3)TPA were designed and synthesized with triphenylamine (TPA) as the core, diketopyrrolopyrrole (DPP) as the arm, and unsubstituted or substituted benzene rings (phenyl, P; 4-fluoro-phenyl, 4-FP; 4-n-butyl-phenyl, 4-BuP) as the end-group. All the three small molecules show relatively narrow optical band gaps (1.68-1.72 eV) and low-lying highest occupied molecular orbital (HOMO) energy levels (-5.09∼-5.13 eV), implying that they are potentially good electron donors for organic solar cells (OSCs). Then, photovoltaic properties of the small molecules blended with [6,6]-phenyl-C(61)-butyric acid methyl ester (PC(61)BM) as electron acceptor were investigated. Among three small molecules, the OSC based on (P-DPP)(3)TPA:PCBM blend exhibits a best power conversion efficiency (PCE) of 2.98% with an open-circuit voltage (V(oc)) of 0.72 V, a short-circuit current density (J(sc)) of 7.94 mA/cm(2), and a fill factor (FF) of 52.2%, which may be ascribed to the highest hole mobility of (P-DPP)(3)TPA.

Generation of native polythiophene/PCBM composite nanoparticles via the combination of ultrasonic micronization of droplets and thermocleaving from aqueous dispersion.

We report the preparation of native polythiophene (n-PT)/[6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) composite nanoparticles from a poly[3-(2-methylhex-2-yl)oxy-carbonyldithiophene] (P3MHOCT)/PCBM aqueous dispersion prepared from an ultrasonically generated emulsion. The subsequent steps involve both ultrasonic generation of microdroplets in argon as a carrier gas and drying followed by thermocleaving of the P3MHOCT component in the gas phase. The chemical transition from P3MHOCT to n-PT was confirmed by Fourier transform infrared (FTIR) spectroscopy. The morphology and size of n-PT/PCBM nanoparticles were determined by atomic force microscopy (AFM), small-angle x-ray scattering (SAXS) and grazing incidence SAXS (GISAXS), giving an average size of ∼ 140 nm. The GISAXS results reveal that n-PT/PCBM nanoparticles pack in an ordered structure as opposed to the P3MHOCT/PCBM nanoparticles. The successful vapour-phase preparation of phase-separated n-PT/PCBM nanoparticles provides a new route to all-aqueous processing of conjugated materials relevant to efficient polymer solar cells with long operational stability. The use of ultrasound was involved in both liquid and gas phases demonstrating it as a low-cost processing method.

A comparative study of UV-fenton, UV-H2O2 and fenton reaction treatment of landfill leachate.

In this study, laboratory experiments were conducted to compare the efficacy of several H2O2-based advanced oxidation processes (AOPs): UV-Fenton, UV-H2O2, and Fenton reagent, to treat landfill leachate with the objective of removing COD and improving the leachate's overall biodegradability (evaluated in terms of BOD5/COD ratio). The results indicated that, at optimized experimental conditions of 25 degrees C, pH 4.0, 4000 mg L(-1) H2O2, 30 mg L(-1) Fe(II) (for UV-Fenton and Fenton) and 60 min reaction time, the UV-Fenton system showed the highest COD removal. The COD removal rate in the H2O2-based AOPs was strongly dependent on the concentration of H2O2 and the pH value. Temperature had little effect on overall COD removal rate in the Fenton and Fenton-like systems. All three systems would result in a significant increase in the ratio of BOD5/COD, from 0.17 to about 0.60, at the applied H2O2 dosage of 4000 mg L(-1). The increase in biodegradability of the AOP leachate indicates that these AOPs would be beneficial for the subsequent biological treatment process. The UV-Fenton process was found to be the most effective approach of these H2O2-based AOPs to enhance the biodegradability and eliminate the colour of the leachate.

Synthesis and photovoltaic properties of ester group functionalized polythiophene derivatives.

To increase the open circuit voltage (V(OC)) of polymer solar cells (PSCs) based on polythiophene, two new ester group functionalized polythiophene derivatives, PCTDT and PCTBDT, were designed and synthesized via alternating copolymerization of thiophene-3-carboxylate (CT) with the 2,2'-bithiophene (DT) and benzodithiophene (BDT) units, respectively. The resulting copolymers exhibited broad and strong absorptions in the visible region, which was similar to that of the commonly used poly(3-hexylthiophene) (P3HT). Through cyclic voltammetry measurements, it was found that both copolymers showed lower HOMO energy levels (-5.27 eV for PCTDT and -5.36 eV for PCTBDT) than that of P3HT (-5.03 eV), indicating that the HOMO energy level could be efficiently reduced by introducing the ester group into the polymer side chain. Photovoltaic properties of the copolymers blended with [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) as electron acceptor were investigated. The obtained two devices possessed both relatively large short circuit current (I(SC)) and higher V(OC) than that of P3HT:PCBM blend. For PCTBDT:PCBM blend, a power conversion efficiency (PCE) up to 2.32%, an I(SC) of 6.94 mA · cm(-2), and a V(OC) of 0.80 V were observed while PCTDT:PCBM system demonstrated a PCE of 1.75% with a V(OC) of 0.68 V.