High-performance, stable and low-cost mesoscopic perovskite （CH3NH3PbI3） solar cells based on poly（3-hexylthiophene）- modified carbon nanotube cathodes

This work explores the use of poly（3- hexylthiophene） （P3HT） modified carbon nanotubes （CNTs@P3HT） for the cathodes of hole transporter free, mesoscopic perovskite （CH3NH3PbI3） solar cells （PSCs）, simultaneously achieving high-performance, high stability and low-cost PSCs. Here the thin P3HT modifier acts as an electron blocker to inhibit electron transfer into CNTs and a hydrophobic polymer binder to tightly cross-link the CNTs together to compact the carbon electrode film and greatly stabilize the solar cell. On the other hand, the presence of CNTs greatly improve the conductivity of P3HT. By optimizing the concentration of the P3HT modifier （2 mg/mL）, we have improved the power conversion efficiencies （PCEs） of CNTs@P3HT based PSCs up to 13.43% with an average efficiency of 12.54%, which is much higher than the pure CNTs based PSCs （best PCE 10.59%） and the sandwich-type P3HT/CNTs based PSCs （best PCE 9.50%）. In addition, the hysteresis of the CNTs@P3HT based PSCs is remarkably reduced due to the intimate interface between the perovskite and CNTs@P3HT electrodes. Degradation of the CNTs@ P3HT based PSCs is also strongly retarded as compared to cells employing the pure CNTs electrode when exposed to the ambient condition of 20%- 40% humidity.

Effect of Device Fabrication Conditions on Photovoltaic Performance of Polymer Solar Cells Based on Poly（3-hexylthiophene） and Indene-CT0 Bisadduct

Effect of the device fabrication conditions on photovoltaic performance of the polymer solar cells based on poly（3-hexylthiophene） （P3HT） as donor and indene-C70 bisadduct （IC70BA） as acceptor was studied systematically. The device fabrication conditions we studied include pre-thermal annealing temperature, active layer thickness, and the P3HT ： IC70BA weight ratios. For devices with a 188-nm-thick active layer of P3HT ： ICToBA （1 ： 1, w ＇ w） blend film and pre-thermal annealing at 150 ℃C for 10 rain, maximum power conversion efficiency （PCE） reached 5.82% with Voc of 0.81 V, Isc of 11.37 mA/cm2, and FF of 64.0% under the illumination of AM1.5G, 100 mW/cm2.

BIOSYNTHESIS AND THERMAL PROPERTIES OF POLY(3-HYDROXYBUTYRATE-co-3-HYDROXYVALERATE)WITH LARGE VARIETY OF HYDROXYVALERATE CONTENTS BY BACILLUS CEREUS

Biosynthesis and thermal properties of poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （PHBV） with different HV （hydrovalerate） content produced by a Bacillus cereus strain were investigated. A large variety of HV contents （up to about 90 mol%） of PHBV could be produced by this strain. Combined nitrogen sources containing both yeast extract and ammonium sulphate were better for cell growth and polyhydroxyalkanoates （PHA） production than either yeast extract or ammonium sulphate alone. Propionic acid is more favorable for the production of HV content than that of valeric acid. Finally, thermal properties of PHBV produced by this strain are found close to the results of other groups.

Vacuum relaxation and annealing-induced enhancement of mobility of regioregular poly(3-hexylthiophene) field-effect transistors

In order to enhance the performance of regioregular poly（3-hexylthiophene） （RR-P3HT） field-effect transistors （FETs）, RR-P3HT FETs are prepared by the spin-coating method followed by vacuum placement and annealing. This paper reports that the crystal structure, the molecule interconnection, the surface morphology, and the charge carrier mobility of RR-P3HT films are affected by vacuum relaxation and annealing. The results reveal that the field-effect mobility of RR-P3HT FETs can reach 4.17×10^-2m^2/（V·s） by vacuum relaxation at room temperature due to an enhanced local self-organization. Furthermore, it reports that an appropriate annealing temperature can facilitate the crystal structure, the orientation and the interconnection of polymer molecules. These results show that the field-effect mobility of device annealed at 150 ℃ for 10 minutes in vacuum at atmosphere and followed by placement for 20 hours in vacuum at room temperature is enhanced dramatically to 9.00×10^-2m^2/（V·s）.

FABRICATION OF HIGHLY HYDROPHOBIC FILMS OF POLY(3-HEXADECYL PYRROLE) NANOPARTICLES BY LANGMUIR-BLODGETT TECHNIQUE

Thin films of poly（3-hexadecyl pyrrole） （P3HDP） nanoparticles have been fabricated by using Langmuir-Blodgett film deposition technique. The structures and morphology of the films were studied by using infrared spectroscopy, scanning and transmission microscopes. The experimental results demonstrated that the nanoparticles were formed by self-assembling P3HDP at air-water surface. The water contact angles of these films with different deposition layers were measured to be as high as 110°.

Effects of concentration and annealing on the performance of regioregular poly(3-hexylthiophene) field-effect transistors

This paper investigates the effects of concentration on the crystalline structure, the morphology, and the charge carrier mobility of regioregular poly（3-hexylthiophene） （RR-P3HT） field-effect transistors （FETs）. The RR-P3HT FETs with RR-P3HT as an active layer with different concentrations of RR-P3HT solution from 0.5 wt% to 2 wt% are prepared. The results indicate that the performance of RR-P3HT FETs improves drastically with the increase of RR-P3HT weight percentages in chloroform solution due to the formation of more microcrystalline lamellae and bigger nanoscale islands. It finds that the field-effect mobility of RR-P3HT FET with 2 wt% can reach 5.78×10^-3 cm^2/Vs which is higher by a factor of 13 than that with 0.5 wt%. Further, an appropriate thermal annealing is adopted to improve the performance of RR-P3HT FETs. The field-effect mobility of RR-P3HT FETs increases drastically to 0.09 cm^2/Vs by thermal annealing at 150 ℃, and the value of on/off current ratio can reach 104.

Effects of catalyst loading amount on the synthesis of poly（3-hexylthiophene） via externally initiated Kumada catalyst-transfer polycondensation

A series of model polymerization are carried out via the one-pot externally initiated Kumada catalyst-transfer polycondensation （KCTP） of 2-bromo-5-chloromagne- slum thiophene monomers, and the excess amount of initiators or catalysts are found no need to be isolated during the polycondensation process. Especially, the impacts of the nickel catalyst loading variation on regioregularity （rr）, yield, molecular weight （Mn）, polydispersity （PDI） and initiation efficiency of poly（3-hexylthiophene） （P3HT） are systematically investigated. The IH NMR, size-exclusion chromatography （SEC）, and MALDI-TOF mass spectroscopy results indicated that an excess amount of catalyst does not influence yield, rr, Mn, and PDI of P3HT, nor the initiation efficiency. However, the PDI of the product is broad, and the Mn and rr values decreased in the absence of 1,3-bis （diphenylphosphino）propane （dppp）. It can be concluded that the in-situ KCTP polymerization of P3HT is a practical and effective process. These results are especially valuable for the synthesis of all-conjugated block copolymers where macroinitiators are used.

Synthesis of Poly (3-acetylpyrrolyl methine) with Azobenzene Side Groups and Study on Its Third-order Nonlinear Optical Property

A novel soluble π-conjugated polymer, poly [（3-acetylpyrrole-2, 5-diyl） p-（N, N-dimethylamino） azobenzylidene] （PAPDMAABE）, was synthesized by condensation of 3-acetylpyrrole with 4-aldehyde-4＇-dimethylaminoazobenzene （ADMAA）. The chemical structure of PAPDMAABE was characterized by Fourier transform infrared spectroscopy （FTIR）, ^1H-NMR, and UV-Vis-NIR spectra. Transmission electron microscope （TEM） analysis for PAPDMAABE indicates that part of PAPDMAABE is in crystal state, due to the short-range order of the polymer. Thermogravimetric analysis （TGA） curve shows that the polymer has good thermal stability and its decomposition temperature is 248℃. The optical band gap of PAPDMAABE obtained from the optical absorption spectrum is about 1.73 eV. The resonant third-order nonlinear optical property of PAPDMAABE at 532 nm was studied using degenerate four-wave mixing （DFWM） technique. The resonant third-order nonlinear optical susceptibility of the polymer is about 7.48×10^-8 esu.

Gas Sensitivity of Poly (3, 4-ethylene dioxythiophene) Prepared by a Modified LB Film Method

An arachidic acid/poly （3, 4-ethylene dioxythiophene） （AA/PEDOT） multilayer Langmuir-Blodgett （LB） film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl molecule and LB film. The gas sensitivity mechanism of poly （3, 4-ethylene dioxythiophene） （PEDOT） multilayer film can be explained by the charge transfer between p system of PEDOT and oxidization HCl system. The gas sensitivity of PEDOT LB film deposited interdigital electrode to HCl was tested. The results showed that film thickness, treating temperature, deposition speed had different influence on film gas sensitivity. The AA/PEDOT film deposited device exhibited nonlinear behavior to HCl gas at lower concentration （20-60 ppm） and linear response behavior at higher gas concentration was observed. The time of the compound LB film of the AA/PEDOT responding to the 30 ppm HCl gas is about 20 seconds, which is far quicker than the time of the film to the PEDOTPRESS film（about 80 seconds）. It is not higher film press to better film. When the film press attains 45 mNs/m, the sensitivity of the AA/PEDOT film on the contrary descends.

Nanofibrous nerve conduits for repair of 30-mm-long sciatic nerve defects

It has been confirmed that nanofibrous poly（3-hydroxybutyrate-co-3-hydroxyvalerate） nerve conduit can promote peripheral nerve regeneration in rats. However, its efficiency in repair of over 30-mm-long sciatic nerve defects needs to be assessed. In this study, we used a nanofibrous poly（3-hydroxybutyrate-co-3-hydroxyvalerate） nerve conduit to bridge a 30-mm-long gap in the rat sciatic nerve. At 4 months after nerve conduit implantation, regenerated nerves were macroscopi- cally observed and histologically assessed. In the nanofibrous graft, the rat sciatic nerve trunk had been reconstructed by restoration of nerve continuity and formation of myelinated nerve fiber. There were Schwann cells and glial cells in the regenerated nerves. Masson＇s trichrome staining showed that there were no pathological changes in the size and structure of gastrocnemius muscle cells on the operated side of rats. These findings suggest that nanofibrous poly（3-hydroxybutyrate-co-3- hydroxyvalerate） nerve conduit is suitable for repair of long-segment sciatic nerve defects.

Platinum Wire Implants Coated with PEDOT/Carbon Nanotube Conducting Polymer Films in the Brain of Rats: A Histological Evaluation

Platinum （Pt） implants coated with poly （3, 4-ethylenedioxythiophene）/carbon nanotube （PEDOT/CNT） composite films were implanted into the brain of rats, and the brain response was evaluated 6 weeks after the implantation. The surface morphology of Pt implants with and without the PEDOT/CNT coating was studied using scanning electron microscopy （SEM）. After 6 weeks post-implantation, the expression of laminin （vascular endothelial marker） and neuronal nuclei （NeuN, neuronal marker） were evaluated by immnohistochemistry. It is revealed that the obvious improvements of the surface density of blood vessels and neurons aound the Pt implants with the coating, which were evidenced by laminin and NeuN staining in the zone within the distance of 150 μm to the implant interface. These results suggest the PEDOT/CNT composite films can improve the biocompatibility of the Pt electrodes while it is implanted in brain.

Comparative evaluation of physico-chemical characteristics of biopolyesters P（3HB） and P（3HB-co-3HV） produced by endophytic Bacillus cereus RCL 02

BACKGROUND： Bacteria endogenously residing within the plant tissues have attracted significant attention for production of biopolyester, polyhydroxyalkanoates （PHAs）. Bacillus cereus RCL 02 （MCC 3436）, a leaf endophyte of oleaginous plant Ricinus communis L. accumulates 81% poly（3-hydroxybutyrate） [P（3HB）] of its cell dry biomass when grown in mineral salts （MS） medium. METHODS： The copolymer production efficiency of B. cereus RCL 02 was evaluated in valeric acid supplemented MS medium under biphasic cultivation condition. The copolymer so produced has been compared with the P（3HB） isolated from RCL 02 in terms of thermal, mechanical and chemical properties. RESULTS： Valeric acid supplementation as co-substrate in the medium has led to the production of copolymer of 3- hydroxybutyrate （3HB） and 3-hydroxyvalerate （3HV） [P（3HB-co-3HV）] with 14.6 mol% 3HV. The identity of the polymers has been confirmed by X-ray diffraction （XRD） analysis, Fourier transform infrared （FTIR） and nuclear magnetic resonance （NMR） spectroscopic studies. Thermogravimetric analysis （TGA） revealed that P（3HB） and P（3HB-co-3HV） films degraded at 278.66℃ and 273.49℃, respectively. The P（3HB-co-3HV） showed lower melting temperature （165.03℃） compared to P （3HB） （170.74℃） according to differential scanning calorimetry （DSC）. Incorporation of 3HV monomers decreased the tensile strength （21.52 MPa）, tensile modulus （0.93 GPa）, storage modulus （E＇） （0.99 GPa） and increased % elongation at break （12.2%） of the copolyester. However, P（3HB） showed better barrier properties with lower water vapor transmission rate （WVTR） of 0.55 g-mil/100 in2/24 h. CONCLUSION： These findings emphasized exploration of endophytic bacterial strain （RCL 02） to produce biodegradable polyesters which might have significant potential for industrial application.

Efficacy of nanofibrous conduits in repair of longsegment sciatic nerve defects

Our previous studies have histomorphologically confirmed that nanofibrous poly（3-hydroxybutyrate- co-3-hydroxyvalerate） conduit can be used to repair 30-mm-long sciatic nerve defects. However, the repair effects on rat behaviors remain poorly understood. In this study, we used nanofibrous poly（3-hydroxybutyrate-co-3-hydroxyvalerate） conduit and autologous sciatic nerve to bridge 30-ram-long rat sciatic nerve gaps. Within 4 months after surgery, rat sciatic nerve functional re- covery was evaluated per month by behavioral analyses, including toe out angle, toe spread anal- ysis, walking track analysis, extensor postural thrust, swimming test, open-field analysis and no- ciceptive function. Results showed that rat sciatic nerve functional recovery was similar after nanofibrous poly（3-hydroxybutyrate-co-3-hydroxyvalerate） conduit and autologous nerve grafting. These findings suggest that nanofibrous poly（3-hydroxybutyrate-co-3-hydroxyvalerate） conduit is suitable in use for repair of long-segment sciatic nerve defects.

Structure of Friction-transferred Highly Oriented Poly(3-hexylthiophene) Thin Films

Oriented thin films of P3HT were obtained by a friction-transfer technique. The morphology and structure of the film were studied by means of optical microscopy, atomic force microscopy and transmission electron microscopy. Optical microscopy observation indicates that large size well-ordered P3HT thin films can be produced by a friction-transfer technique. Highly ordered lamellae were observed in P3HT friction-transferred films by electron microscopy. Electron diffraction results confirm the existence of high orientation with the a- and c-axes of P3HT crystals aligned in the film plane while the c-axis parallel to the friction-transfer direction. The atomic force microscopy observation of the as-prepared P3HT thin film shows, however, a featureless top surface morphology, indicating the structure inhomogeneity of the obtained film. To get highly oriented P3HT thin films with homogenous structure, high temperature annealing, solvent vapor annealing and self-seeding recrystallization of the friction-transferred film were performed. It is confirmed that solvent vapor annealing and self-seeding recrystallization methods are efficient in improving the surface morphology and structure of the friction- transferred P3HT thin film. Highly oriented P3HT films with unique structure can be obtained through friction-transfer with subsequent solvent vapor annealing and self-seeding recrystallization.

PREPARATION AND CHARACTERIZATION OF HUMIDITY SENSOR BASED ON POLY(3-ALKYL)PYRROLE CONTAINING PHOSPHONIC ACID GROUPS

Poly（3-alkyl）pyrroles containing phosphonic acid groups with different alkyl segment lengths were chemical synthesized and the properties were measured by FTIR and UV-Vis spectroscopy. FTIR and UV-Vis results showed that the synthesized polymers were in a low doping level through chemical polymerization. By spin-coating on the surface of substrates, the polymer can be used as a humidity sensor. The change of DC electric current of the polypyrroles varies with the chain length of the alkyl substituents. The capacitance increases with the increase of the humidity and resistance decreases with the increase of humidity. This result is different from that ofpolypyrrole without alkyl substituents due to the influence of the phosphonic acid group. The sensor showed the resistive-type at high relative humidity, and the capacitive- type at the low relative humidity. The sensor exhibited very fast response to the change of environment humidity.

Effects of Quenching Temperature and Time on Pore Diameter of Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) Porous Scaffolds and MC3T3-E1 Osteoblast Response to the Scaffolds

Poly（3-hydroxybutyrate-co-3-hydroxyhexanoate） （PHBHHx） scaffolds were prepared by thermally inducing phase separation （TIPS） for bone reconstruction. Scanning electron microscopy and porosity measurements were used to analyze the structure and properties of the scaffolds. The pore diameter of the scaffolds could be easily controlled by changing the quenching temperature and time. The biocompatibility was assessed by examining the proliferation and morphology of MC 3T3-E1 osteoprogenitor cells seeded on the scaffolds. Cultures grown in the presence of a source of phosphate ions showed the formation of a mineralized extracellular matrix. The results indicate that PHBHHx scaffolds prepared using TIPS are a promising candidate for bone reconstruction.

Analysis on the Characteristic Properties of PEDOT Nano-particle Based on Reversed Micelle Method

Based on the study of a new type of conducting polymer poly （3,4-ethylenedioxythiophene） （PEDOT）,we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows： the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible （UV-Vis） spectroscopy,Fourier-transform infrared （FT- IR） spectrum,scanning electron microscopy（SEM） and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.

Synthesis and Characterization of a Novel Ionic Liquid Polymer: Poly(1-(3-aminobenzyl)-3-methylimidazolium chloride)

A new type of polymerizable ionic liquid （IL） 1-（3-aminobenzyl）-3-methylimidazolium chloride （AMIC） was synthesized to obtain a novel polymer salt poly（1-（3-aminobenzyl）-3-methylimidazolium chloride） （PAMIC）. The AMIC was structurally characterized by mass spectrometry and Fourier transform infrared spectrometry （FTIR）. The structure, morphology and properties of PAMIC were investigated by FTIR, ultraviolet visible absorption spectra （UV-Vis）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDX）, conductivity measurement and thermo- gravimetric analysis （TGA）. The PAMIC was spherulitic with an average diameter of about 50 nm and showed high conductivity and excellent thermal stability.

Electronic Structure Effect of Polythiophene Derivatives and Nano N-Zn-Ag/TiO2 on Performance of Organic Thin Film Solar Cell

Nanocrystal N-Zn-Ag/TiO2 powders were prepared with N-Zn/TiO2 by photo deposition method. A series of pure polymers P3HT[poly（3-hexylthiophene）], P3OT[poly（3-octylthiophene）], P3DT[poly（3-decylthiophene）] and P3DDT[poly（3-dodecylthiophene）], was synthesized, which were used to synthesize p-n type semiconductor mate- rials P3HT/N-Zn-Ag-TiO2, P3OT/N-Zn-Ag-TiO2, P3DT/N-Zn-Ag-TiO2 and P3DDT/N-Zn-Ag-TiO2 by in situ che- mical method. X-Ray diffraction（XRD） and infrared（IR） spectroscopy showed the structure of the polymers and complexes. Ultraviolet-visible（UV-Vis） spectra and cyclic voltammograms（CV） showed the optical and electronic performance of the polymers and complexes. Two new single and double organic thin film heterojunction solar cells were prepared with the above mentioned synthesized powders as raw materials. Current-voltage（I-V） measurements indicate that the conversion efficiency of the single organic thin film heterojunction solar cell is higher than that of the double organic thin film heterojunction solar cells. Single organic thin film heterojunction solar cells based on P3DT/N-Zn-Ag-TiO2 can get a photoelectric conversion efficiency of 0.0408%. The performance of electronic trans- form between electron donor and acceptor on organic thin film solar cells was researched.

Visible light-driven superoxide generation by conjugated polymers for organic synthesis

Benefiting from their unique delocalized electronic structure, conjugated polymer-based semiconductors are widely applied in the fields of organic electronics, sensors, and biomedical applications. However, the photocatalytic properties of conjugated polymers have been seldom studied because of their unsuitable band structures. Herein, we creatively demonstrate that the band structures of conjugated polymers are strongly related to their degree of polymerization （DP）, offering an effective strategy for the design of metal-free photocatalysts with tunable light absorption properties. Taking poly（3- hexylthiophene） （PHT） as an example, we show that PHT nanofibers with a suitable DP are a novel visible light-driven photocatalyst, which can readily convert molecular oxygen into superoxide ions. Benefiting from the high selectivity of the generated superoxides, the PHT nanofibers display outstanding activity for the aerobic oxidation of amines into imines with nearly 100% conversion and selectivity. This study offers a new strategy for the design of advanced coniugated Dolvrner-based Dhotocatalvsts.