The solution structures of organic carbonate solvents (ethylene (EC), propylene (PC), dimethyl (DMC), and diethyl (DEC)) as electrolyte solutions LiPF6 were investigated with FTIR NMR spectroscopy DFT computational methods. Both coordinated uncoordinated are observed by IR spectroscopy, allowing the determination solvent coordination numbers, which a range from 2 to 5. predominant species in changes function concentration. At low salt concentrations (<1.2 M), is solvent-separated ion pair,...

Abstract A method with good precision has been developed to quantitatively measure the degree of α‐, β‐, and γ crystallinity in poly(vinylidene fluoride) (PVDF) by means infrared spectroscopy. The phase composition solution‐deposited PVDF films was found be strongly influenced presence hydrophilic residues on silicon substrate, relative humidity present at film deposition, spatial position thermal treatment deposited film. Films produced pristine surfaces gave predominantly α‐phase PVDF, but...

Thin films of PVDF were deposited from a variety solution conditions and examined by IR spectroscopy scanning electron microscopy. Methods to rapidly assess the film thickness phase composition have been developed. In particular, formation ferroelectric β can be controlled solvent, notably water content. Using hydrated salt in casting solvent reproducibly formed with high However, also induces increased surface roughness films. The nature is influenced kinetics evaporation process, this was...

The photoconductivity of films single-wall carbon nanotubes has been studied under continuous-wave near-infrared illumination. photocurrent exhibits a linear response with the light intensity and bias voltage up to 5 V. temporal photoresponse on/off step illumination shows relatively slow relaxation time (4.3 s for thickness ∼500 nm), which can be interpreted in terms kinetic model that takes into account binding photoelectrons adsorbed oxygen. Possible applications this photosensitive...

Liquid electrolytes typically used in commercial lithium-ion batteries are comprised of lithium hexafluorophosphate carbonate solvents. This electrolyte undergoes thermal decomposition at moderately elevated temperatures (80–100°C), encountered the normal operation these rechargeable power sources, to quantitatively generate highly toxic alkylfluorophosphates. The occurs via an autocatalytic mechanism initiated by trace impurities water or alcohol. is inhibited presence metal oxides...

Photovoltaic devices based on single-walled carbon nanotubes (SWNTs) and n-silicon heterojunctions have been fabricated by a spray deposition process. We provide direct evidence that serve as an active photosensing material involved directly in the photon absorption process well contributing to charge separation, transport collection. The characteristic band of SWNT photoconductivity spectrum matches S(11) semiconducting SWNTs 7,6 chirality. Centrifugation provides two fractions. sediment...

Abstract The oxidative polymerization of o ‐phenylenediamine was studied under a variety conditions. At room temperature the reaction with ammonium persulfate in HCl acid medium gives dimer, 2,3‐diaminophenazine. same at 70°C results trimer an open structure, [3‐amino‐2(3,4‐diaminophenylamino)]‐phenazine hydrochloride. 118°C, glacial acetic poly(aminophenazine) acetate, analogous to polyaniline. However, either because atactic nature polymer and consequences this on stability charge carriers...

Conjugated polymers entrapped in porous silicon microcavity have been studied as optical sensors for low volatility explosives such trinitrotoluene. The fluorescence spectra of were modulated by the via a spectral “hole” that matches resonance peak reflectance. Exposure containing polymer to vapor results red shift and hole, accompanied quenching fluorescence. This multiplexed response provides multiple monitoring parameters, enabling development an sensor array detection target explosive vapor.

Self-organized rhodamine 6G (Rh6G) thin films on a glass substrate were prepared by spin-coating, dip-coating, and drop-coating. The thickness of the Rh6G layer strongly influences both absorption emission spectra, which are accounted for monomers, exciton excimer formation, molecular aggregation. Submonolayer show one maximum apparent shoulder in spectrum, but three peaks required deconvolution spectrum. As film becomes thicker, observed shifts to lower energy, fourth peak is deconvolution....

The α phase (or form II) of poly(vinylidene fluoride), PVF2, produced from an acetone/N,N-dimethylformamide (DMF) solution gave different surface morphologies, depending on the solvation temperature PVF2 solution, DMF concentration, and relative humidity when deposited onto a smooth silicon substrate. Solutions prepared at less than 30 °C always rise to transparent films. However, solutions temperatures greater 50 resulted in rough opaque, white depositing high film low humidity. aging...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of 2,3-butanedione dihydrazone and IR study higher polyazines: a new class polymeric conductorsCharles R. Hauer, Gregory S. King, Erica L. McCool, William B. Euler, Joseph D. Ferrara, Wiley J. YoungsCite this: Am. Chem. Soc. 1987, 109, 19, 5760–5765Publication Date (Print):September 1, 1987Publication History Published online1 May 2002Published inissue 1 September...

Crystal structures were determined for two compounds, 2-pyridinecarboxaldehydeazine, 1, and biacetylazine, 2. 2-Pyridinecarboxaldehydeazine crystallizes in space group P21/c with a = 10.0487(7) Å, b 4.6452(7) c 11.6700(11) β 91.030(6)°, V 544.65(10) Å3, Z 2, R 0.0345. Biacetylazine C2/c 9.879(7) 12.409(4) 7.950(6) 98.44(6)°, 964.0(11) 4, 0.0496. Comparison of the imine bond lengths these other azine diimine systems found literature suggests that conjugation imines is better through...

We demonstrate a solar cell based on n-type nanoporous Si (PSi) filled with copper phthalocyanine (CuPC) and its derivatives (including discotic liquid crystal form). The CuPC device shows conversion efficiency up to 2% under white light illumination (20–30mW∕cm2), distinct from cells alkyl chains attached the core. It is concluded that critical issue for efficient photocarrier generation distance between core PSi surface. Both organic inorganic components contribute photoinduced charge...

We report a room temperature mid-infrared photodetector based on carbon nanotube-silicon heterojunction nanostructure. The observed band (8–12 μm) in the photocurrent spectrum is consistent with estimated gap energy of semiconducting multiwall nanotubes (15 to 30 nm diameter). fast response time (16 ms) and small change (∼10−8 K) upon infrared light suggest that not due bolometric effect. determined primary mechanism this spectral range associated photon absorption multiwalled followed by...

Abstract An anisotropic carbon nanotube (CNT)‐polymer composite for bolometric applications in the mid‐IR spectral range (2.5–20 μm) is studied. Composite alignment conjunction with non‐uniform distribution of CNTs polymer matrix allows a significant enhancement temperature coefficient resistance (0.82% K −1 ) respect to uniform (0.24% ). As result responsivity ≈ 500 V W reached, which highest CNT‐based bolometers reported date. Such remarkable optical and thermal characteristics are...

An actuating system composed of nafion ionomeric polymer coated with single-walled carbon nanotubes electrodes was studied as an electromechanical actuator. The actuator gives a sizable mechanical response to low voltages (turn-on voltage approximately 2.5 V) under open-air conditions, i.e., in the absence surrounding supporting electrolyte. is active both dc and ac bias has strong resonance at frequencies which dependent upon size using Fourier transform infrared vis-NIR spectroscopies,...

A fluorometric sensing array was developed to detect and discern common military explosives materials used in improvised explosive devices (IEDs). Xanthene-based fluorophores were chosen as reporter molecules exposed analytes DMF solution. Unique responses observed for each analyte, with the strongest resulting from trinitrobenzene (TNB) or trinitrotoluene (TNT) addition. Evidence substantial electron transfer (ET) between TNB TNT products observed. Computational results indicate that...

The spectral response of ultrathin films rhodamine 6G (Rh6G) cast onto polyvinylidenefluoride (PVDF) coated glass slides is studied to investigate a perceived fluorescence emission enhancement. Varying the thickness Rh6G layer (submonolayer multiple layers) on PVDF revealed existence species surface, similar previous reports glass. Excitation spectra show that J-type excitons are not responsible for an Trends in intensity surface roughness prevents molecules from organizing way they would...

ADVERTISEMENT RETURN TO ISSUEPREVLab-ExptNEXTThe Modern Student Laboratory: Polyaniline-A Conducting Polymer: Electrochemical Synthesis and Electrochromic PropertiesBradford Charles Sherman , William B. Euler R. Ren Force Cite this: J. Chem. Educ. 1994, 71, 4, A94Publication Date (Print):April 1, 1994Publication History Received3 August 2009Published online1 April 1994Published inissue 1 1994https://doi.org/10.1021/ed071pA94RIGHTS & PERMISSIONSArticle Views1178Altmetric-Citations30LEARN...