Dual-crosslinked reduced graphene oxide/polyimide aerogels possessing regulable superelasticity, fatigue resistance, and rigidity for thermal insulation and flame retardant protection in harsh conditions.

Polyimide (PI) aerogels have various applications in aerospace, national defense, military industry, and rail transit equipment. This paper reports a series of ultra-lightweight, high elasticity, high strength, low thermal conductivity, and high flame retardant rGO/PI nanocomposite aerogels prepared by the ice templating method. The effects of freezing processes (unidirectional freezing and random freezing), chemical composition, and environmental temperature (-196-200 °C) on the morphology, mechanical, and thermal properties of the aerogels were systematically studied.

Synthesis and Characterization of Novel Triphenylamine-Containing Electrochromic Polyimides with Benzimidazole Substituents.

Two novel electrochromic aromatic polyimides (named as TPA-BIA-PI and TPA-BIB-PI, respectively) with pendent benzimidazole group were synthesized from 1,2-Diphenyl-N,N'-di-4-aminophenyl-5-amino-benzimidazole and 4-Amino-4'-aminophenyl-4″-1-phenyl-benzimidazolyl-phenyl-aniline with 4,4'-(hexafluoroisopropane) phthalic anhydride (6FDA) via two-step polymerization process, respectively. Then, polyimide films were prepared on ITO-conductive glass by electrostatic spraying, and their electrochromic properties were studied. The results showed that due to the π-π* transitions, the maximum UV-Vis absorption bands of TPA-BIA-PI and TPA-BIB-PI films were located at about 314 nm and 346 nm, respectively.

Polyimides containing a novel bisbenzoxazole with high and low CTE.

A novel diamine named (2,2'-bibenzoxazole)-5,5'-diamine (DBOA) and derived polyimides (PIs) were successfully synthesized. The rigid, linear, symmetrical molecular structure and the strong charge transfer complex (CTC) were considered to be the reasons for the improved molecular packing and enhanced thermal properties of the polymers. These DBOA based PIs exhibited a higher glass transition temperature ( ) and lower coefficient of thermal expansion (CTE) than traditional benzoxazole (BOA) based PIs.

Design of a novel poly(aryl ether nitrile)-based composite ultrafiltration membrane with improved permeability and antifouling performance using zwitterionic modified nano-silica.

Zwitterionic nano-silica (SiO NPs) obtained by lysine surface modification was used as a hydrophilic inorganic filler for preparing a poly(aryl ether nitrile) (PEN) nanocomposite membrane an immersion precipitation phase inversion method. The effects of zwitterionic SiO NPs addition on the morphology, separation and antifouling performance of the synthesized membranes were investigated. Zwitterionic surface modification effectively avoided the agglomeration of SiO NPs.

A novel porous hollow carboxyl-polysulfone microsphere for selective removal of cationic dyes.

Herein, we obtained porous hollow carboxyl-polysulfone (PH-CPSF) microspheres through non-solvent-induced phase separation (NIPS) method and simple modification, used as highly efficient adsorbents for removing cationic dyes from sewage. The resulting PH-CPSF microspheres possess a hollow core and sponge-like shell structure, with high surface area, durable chemical inertness and structural stability. The as-synthesized PH-CPSF microspheres deliver a desirable adsorption effect after deprotonation treatment, with an adsorption capacity reaching up to 154.

Preparation and Characterization of Reduced Graphene Oxide /TiO Blended Polyphenylene sulfone Antifouling Composite Membrane With Improved Photocatalytic Degradation Performance.

Nanosized titanium oxide (TiO)-based photocatalysts have exhibited great potential for the degradation of organic contaminants, while their weak absorption of visible light limits the photocatalytic efficiency. Herein, a novel reduced graphene oxide/TiO-polyphenylenesulfone (rGO/TiO-PPSU) hybrid ultrafiltration membrane has been successfully prepared via a non-solvent induced phase-separation method, in which the synergistic coupling between the rGO and TiO could endowed the fabricated membranes with visible-light-driven efficient photocatalytically degradation of organic pollutants and outstanding photocatalytic and antifouling properties. Compared with the PPSU membranes prepared with Graphene oxide and TiO, respectively, the rGO/TiO-PPSU membrane demonstrated significant photodegradation towards phenazopyridine hydrochloride (PhP) solution under ultraviolet light (improved about 71 and 43%) and visible light (improved about 153 and 103%).

Novel TiO Nanoparticles/Polysulfone Composite Hollow Microspheres for Photocatalytic Degradation.

Nanosized titanium oxide (TiO) material is a promising photocatalyst for the degradation of organic pollutants, whereas the difficulty of its recycling hinders its practical application. Herein, we reported the preparation of a novel titanium oxide/polysulfone (TiNPs/PSF) composite hollow microspheres by the combination of Pickering emulsification and the solvent evaporation technique and their application for the photodegradation of methyl blue (MB). P25 TiO nanoparticles dispersed on the surface of PSF microspheres.

Incorporation of -phenyl in poly(benzimidazole imide)s and improvement in HO-absorbtion and transparency.

5-Amine-2-(4-amino-benzene)-1-phenyl-benzimidazole (-PhPABZ) was successfully synthesized and polymerized with 3,3',4,4'-biphenyl tetracarboxylic dianhydride (BPDA) to obtain a novel -phenyl-poly(benzimidazole imide) (-Ph-PBII). The successful incorporation of -phenyl addressed the issue of high HO-absorption of traditional PBIIs while retained the superheat resistance property. The resulting -Ph-PBII possessed a high glass-transition temperature ( ) up to 425 °C and a low affinity for water of 1.

Fabrication of ultrafiltration membranes by poly (aryl ether nitrile) with poly (ethylene glycol) as additives.

A new kind of flat sheet ultrafiltration membrane was prepared by a promising membrane material, poly (aryl ether nitrile) (PEN), via non-solvent induced phase separation. The effect of solvents, N-methyl-2-pyrrolidone (NMP) and dimethyl acetamide (DMAc), as well as additive of poly (ethylene glycol) (PEG) with different molecular weights on the structure and permeation performance of synthesized membranes were investigated. Comparing with NMP, DMAc is more suitable for the casting solution preparation due to better solubility.

Preparation of a Fluorocarbon Polymerizable Surfactant and Its Application in Emulsion Polymerization of Fluorine-Containing Acrylate.

A novel polymerizable fluorocarbon surfactant, perfluoro (4⁻methyl⁻3, 6⁻dioxaoct⁻7⁻ene) sodium sulfonate (PSVNa), was synthesized and characterized. The fluorocarbon surfactant PSVNa and its mixture PSVNa/SDS were used as emulsifiers during the emulsion polymerization of DFHMA/MMA. The investigation of polymerization kinetics, particle size, and stability of the emulsions revealed that PSVNa has excellent emulsifying properties.

A general approach for fabrication of nitrogen-doped graphene sheets and its application in supercapacitors.

In this paper, a general and efficient strategy has been developed to produce nitrogen-doped graphene sheets (NGs) based on hard and soft acids and bases (HSAB) theory. Under hydrothermal conditions, any salt with amphiprotic character have a strong tendency to hydrolysis, it is possible to provide reducing agent and nitrogen source simultaneously. It is worth noting that, NGs can be prepared under hydrothermal conditions by using some common ammonium salts with hard acid-soft base pairs as nitrogen-doping agents.

Solution processable titanium dioxide precursor and nanoparticulated ink: application in Dye Sensitized Solar Cells.

Colloidal TiO2 anatase nanoparticles of 4-8 nm diameter capped with 3,6,9-trioxadecanoic acid (TODA) were synthesized at low temperature using water and ethanol as the solvents. ATR-FTIR and (1)H NMR characterization showed the capping acid capability of stabilizing the TiO2 nanoparticles through labile hydrogen bonds. The presence of the capping ligand permitted the further preparation of homogeneous and stable colloidal dispersions of the TiO2 powder in aqueous media.

A phenyl-capped aniline tetramer for Z907/tert-butylpyridine-based dye-sensitized solar cells and molecular modelling of the device.

Z907-sensitized solar cells incorporating a phenyl-capped aniline tetramer (EPAT) as a substitute of the iodine/iodide redox couple in the electrolytes produce an enhanced open-circuit voltage and short circuit photocurrent density when tert-butylpyridine (TBP) is added to the electrolyte.

New D-π-A-conjugated organic sensitizers based on 4H-pyran-4-ylidene donors for highly efficient dye-sensitized solar cells.

We have synthesized a series of four new promising D-π-A conjugated organic sensitizers with a proaromatic 4H-pyran-4-ylidene as a donor, a thiophene ring in the bridge, and 2-cyanoacrilic acid as acceptor. Comparison between different donor substituents and the modification of the thiophene ring resulted in molar extinction coefficients as high as 36399 M(-1) cm(-1) at 551 nm. The photovoltaic properties of the DSSCs demonstrate power conversion efficiencies as high as 5.

Iodine/iodide-free dye-sensitized solar cells.

Dye-sensitized solar cells (DSSCs) are built from nanocrystalline anatase TiO(2) with a 101 crystal face (nc-TiO(2)) onto which a dye is absorbed, ruthenium complex sensitizers, fluid I(-)/I(3)(-) redox couples with electrolytes, and a Pt-coated counter electrode. DSSCs have now reached efficiencies as high as 11%, and G24 Innovation (Cardiff, U.K.

Preparation and characterization of polyaniline microwires containing CdS nanoparticles.

Polyaniline(PANI) microwires containing CdS nanoparticles have been prepared by introducing hydrogen bonding and/or electrostatic interaction between mercaptocarboxylic acid capped CdS nanoparticles and PANI. SEM and TEM proved them to be wire-like structures. PL spectra of the PANI/CdS complex is blue-shifted by 14 nm compared to CdS nanoparticles in N-methylpyrrolidinone(NMP).