3,3’,5,5’-四甲基联苯-4,4’-二羟乙基醚的合成与表征

以3,3’,5,5’-四甲基联苯二酚(TMBP)和2-氯乙醇为原料两步法合成了3,3’,5,5’-四甲基联苯-4,4’-二羟乙基醚。探讨了反应物物质的量比、碱用量、催化剂及反应温度对转化率的影响。结果表明,在n(TMBP)∶n(NaOH)∶n(2-氯乙醇)=1∶3.0∶2.5,反应时间为10h,反应温度为110℃条件下,总转化率达95.9%,纯度达99.1%。并用红外、质谱以及核磁等方法对产物结构进行了表征。     

Nano-C(60) : a novel, effective, fluorescent sensing platform for biomolecular detection

Water-soluble nano-C(60) can serve as a novel, effective, fluorescent sensing platform for biomolecular detection with high sensitivity and selectivity. In this paper, fluorescent detection of DNA and thrombin via nano-C(60) is demonstrated for the first time. The principle of the assay lies in the fact that the adsorption of the fluorescently labeled single-stranded DNA (ssDNA) probe by nano-C(60) leads to substantial fluorescence quenching. In the presence of a target, the biomolecular mutual interaction suppresses this quenching, signaling the existence of the target. This sensing system rivals graphene oxide but is superior to other carbon-structure-based systems. The present method can also achieve multiplex DNA detection and withstand the interference from human blood serum.     

Synthesis of polyimide from 5,5'-bis(bromomethyl)-2,2':6',2'-terpyridine and investigation of the polymer sorption behavior towards some metal ions

The synthesis of a terpyridine-based polyimide sorbent for solid-phase extraction (SPE) of some metal ions is described. For this purpose, 5,5'-bis(bromomethyl)-2,2':6',2'-terpyridine was polymerized with the corresponding diimide derivatives of dianhyrides to give polyimides utilizing terpyridine unit in the main chain. This polymer was used for its extraction capabilities for Pb(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II), at different pH. Under competitive conditions and at pH<0.6, the selectivity order was Pb approximately Cd approximately Zn. Enhanced selectivity was observed at pH 3.5, the order was Cu>Ni>Zn approximately Cd approximately Pb. Quantitative recoveries>97% were observed for all metals in case loading was stopped before reaching the point of breakthrough. As the synthesized polyimides are insoluble in water, solid-liquid extractions have been carried out and the resins sorption for mixture of basic and/or precious metals have been studied under various experimental conditions (reaction time and hydrochloric acid concentration).     

Removal of organic pollutants from 2,2',5,5'-tetrachlorobenzidine (TCB) industrial wastewater by micro-electrochemical oxidation and air-stripping

A feasible method for treatment of the wastewater from the two-staged neutralization in 2,2',5,5'-tetrachlorobenzidine (TCB) manufacturing processes, a refractory dye intermediate effluents, based on combined micro-electrochemical oxidation or iron-chipping filtration (ICF) and air-stripping reactor (ASR), was developed. On conditions of HRT 1h, pH 3.0 in ICF and HRT 38 h, gas-liquid ratio 15, pH 6.0-8.65, temperature 26 degrees C in ASR, the overall COD, color, TCB and NH(4)(+)-N removal were 96.8%, 91%, 87.61% and 62%, respectively, during the treatment of TCB wastewater from the two-staged neutralization dissolved by methanol. The averaged 18.3%, 81.7% of the total degraded COD, 35.2%, 64.8% of TCB were carried out in ICF and ASR, respectively. NH(4)(+)-N removal was finished mainly in ASR. The experimental results indicated that the combined micro-electrochemical oxidation and air-stripping process performed good treatment of COD, color, TCB and NH(4)(+)-N removal in TCB wastewater from the two-staged neutralization dissolved by ethanol or acetone, came up the discharge standard in China. But the TCB wastewater from the two-staged neutralization dissolved by methanol should be deeply treated before discharged.     

Optical and morphological characterisation of a silver nanoparticle/fluorescent poly(phenylenethynylene) composite for optical biosensors

Thiol silver nanoparticles prepared by the phase transfer method have been mixed with a fluorescent poly(phenylenethynylene) sequenced with dithioester-diethylsulfide moieties in order to develop a nanocomposite for its possible application in optical biosensors for the detection and attack of fungi such as Paecilomyces variotii. Films have been prepared by dipping technique and characterized by AFM, XPS, UV-Visible and fluorescence spectroscopy. Optical Absorption properties of the nanocomposite are similar to those of the polymer with an absorption tail in the visible which supports the presence of silver nanoparticles. Despite the lack of fluorescence of the nanoparticles, the composite emits in the yellow green region and the intensity of the fluorescence of the nanocomposite film decreases after the immersion in the culture thus permitting the detection of the fungus by this technique. The fungus can be deposited on films of both the polymer and nanocomposite, nevertheless only in the latter case, an attack on mycelium is observed revealing the fungicidal effect of silver nanoparticles in the nanocomposite.     

Monodisperse plasticized poly(vinyl chloride) fluorescent microspheres for selective ionophore-based sensing and extraction.

A convenient method for the preparation of monodisperse, plasticized poly(vinyl chloride) particles based on an automated particle casting technique is described. The particles are made highly selective for a number of ions by doping them with ionophores and other active components, in complete analogy to thin-film or fiber-optic chemical sensors. The approach used here produces spheres of high monodispersity at a rate of approximately 20000 particles/s. The casting process is based on a reproducible polymer drop formation and precipitation process, and the particles are formed under very mild, nonreactive conditions. This allows one to conveniently incorporate known amounts of different active components into the polymers. As an initial example, the particles are doped with three optical sensing components, the sodium ionophore tert-butylcalix[4]arene tetraethyl ester, the H+-chromoionophore ETH 5294, and the anionic additive sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate. The particles are found to be of spherical shape with a diameter of approximately 10 microm. They respond individually and selectively to sodium according to classical optode theory, as determined by fluorescence microscopy. With a RSD of 1.6%, sensing reproducibility from particle to particle is excellent. This technique may allow the development of mass-produced chemically selective microspheres on the basis of bulk extraction processes.     

All-solid-state hydrogen sensing microelectrodes based on novel PPy[3,3′-Co(1,2-C2B9H11)2] as a solid internal contact

Planar all-solid-state hydrogen sensing microelectrodes have been constructed and investigated. A novel conductive polymer, polypyrrole (PPy) doped with cobaltabis(dicarbollide) ions ([3,3′-Co(1,2-C₂B₉H₁₁)₂]⁻), thin film was galvanostatically grown over a solid substrate (Pt) and acted as an internal solid contact layer between the solid surface (Pt) and the polymeric sensitive membrane. The potentiometric response characteristics of this new kind of microelectrode based on tri-n-dodecylamine (TDDA) ionophore were evaluated. They exhibited excellent selectivity for the primary ion and a linear response over the pH range 3.5–11.0 with a slope of 52 ± 2 mV decade^− 1. The selectivity properties have been examined. The results obtained were comparable to that of a conventional ion-selective electrode (ISE) based on the same ionophore.     

Synthesis and optical properties of naturally occurring fluorescent mineral,ferroan sphalerite,inspired (Fe,Zn)S nanoparticles

Inspired by the naturally occurring fluorescent mineral, ferroan sphalerite, [(Fe,Zn)S] nanoparticles were synthesized by a three component reaction of [Fe(Mes)₂]₂ (Mes = mesityl or C₆H₂Me₃-2,4,6), [Zn(Et)(ONep)(py)]₂, and elemental S via both solution and solvothermal routes. The resultant nanoparticles are ≤3 nm and absorb at λ_max = 281 nm emitting a bright blue color (λ_em ∼400 nm). The synthesis of fluorescent ferroan sphalerite nanoparticles that emit at ∼400 nm was realized through solution and solvothermal routes.     

Polyelectrolyte microshells as carriers for fluorescent sensors: loading and sensing properties of a ruthenium-based oxygen indicator

A strategy for the design and fabrication of microcapsule-based fluorescent biosensors containing indicators and internal references is described. The rationale for this work is the physical immobilization and chemical separation of assay chemistry for use in biological environments. Using the general approach of depositing oppositely charged species on colloidal micro/nanotemplates, a sensor system employing polyelectrolyte microshells for uptake of functional molecules is proposed, and experiments to demonstrate the feasibility of nanoengineering the sensor properties are described in the context of an oxygen sensor. Methods for immobilization and entrapment of fluorescent indicator and reference dyes are shown, along with the pH dependence of this process. Embedded dyes are shown to be stable and retain their function, as demonstrated with oxygen-sensitivity experiments of loaded microcapsules. Although oxygen sensitivity is presented as an example of a specific application, the overall strategy is likely more generally useful. The work suggests that polyelectrolyte microshells may be used as a platform to develop novel sensors by entrapment of functional materials.     

2,4,6-Tris (2-pyridyl)-1,3,5-triazine nanobelts as an effective fluorescent sensing platform for DNA detection

In the present study, we report on the use of 2,4,6-tris (2-pyridyl)-1,3,5-triazine nanobelts (TPTNBs) as an effective fluorescent sensing platform for DNA detection for the first time. The general concept used in this approach is based on adsorption of fluorescently labeled single-stranded DNA (ssDNA) probe by TPTNB, due to the strong pi-pi stacking between unpaired DNA bases and TPTNB. As a result, the fluorophor is brought into close proximity of TPTNB, leading to fluorescence quenching. Upon presence of the target ssDNA, specific hybridization with the target takes place to form a double-stranded DNA (dsDNA). The resultant dsDNA cannot be adsorbed by TPTNB due to its rigid conformation and the absence of unpaired DNA bases. Thus, the fluorophor is seperated from TPTNB accompanied by fluorescence recovery. The present system shows a detection limit as low as 3 nM and has a high selectivity down to single-base mismatch.     

Gaussian-optics-based optical modeling and characterization of a Fabry-Perot microcavity for sensing applications

A generalized study has been carried out on the modeling of a Fabry-Perot microcavity for sensing applications. Different analytical models on transmission characteristics of a Fabry-Perot microcavity are established by using plane-wave-based techniques, such as the Macleod characteristic matrix technique, the transfer matrix technique, and Smith's technique. A novel Gaussian-optics-based model for a Fabry-Perot microcavity illuminated by a laser beam is then developed and validated. The influence of laser beam waist on microcavity optical response is investigated, and the required minimal beam waist size is explored to ensure a useful optical response for sensing applications that can be accurately predicted by plane-wave optics. Also, the perturbations of microcavity performance induced by different types of microcavity mirror imperfections are discussed, based on the novel optical model. The prototype of the proposed Fabry-Perot microcavity for sensing applications has been successfully fabricated and characterized.     

Studies on the nonlinear optical single crystal: Ammonium d,l-tartrate (C4H9NO6)

The organic nonlinear optical material ammonium d,l-tartrate single crystal has been successfully grown by slow evaporation solution technique (SEST). The grown crystals were characterized by single crystal XRD and the lattice parameters have been confirmed. The structural perfection of the grown crystal was analyzed by high-resolution X-ray diffraction measurement. The optical transmittance spectrum shows that the material has a good optical transparency in the entire visible region with the UV cut-off wavelength at 234 nm. Thermogravimetric and differential scanning calorimetric measurements were performed to study the thermal properties of the grown crystal. Chemical etching studies were attempted to determine the dislocation density of the grown crystal. Mechanical behavior was assessed using Vickers hardness testing carried out on (0 0 1) crystallographic plane. The Kurtz–Perry powder SHG technique confirms the NLO property of the grown crystal and the efficiency of AMT crystal was found to be 1.3 times that of standard KDP crystal.     

Functionalization of multi-walled carbon nanotubes with bis(2,2':6',2"-terpyridine) ruthenium(II)-connected diblock polymer

Multi-walled carbon nanotubes (MWCNTs) were functionalized with a bis(2,2':6',2"-terpyridine) ruthenium(ll)-connected diblock poly(N-isopropyacryamide) (RuTpyPNIPAM) by a simple methodology of covalent amidation. The composition and structure of the functionalized ruthenium multi-walled carbon nanotubes (RuMWCNTs) were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscopy (SEM). These characterization methods confirm that after functionalization, ruthenium metallopolymer are interconnected or attached as aggregated structures on the surface of the carbon nanotubes.     

Tailoring the structural,electrical, and optical features of Erbium(III)-Tris(8-hydroxyquinolinato) nanostructured films for optical applications: effect of film thickness

This paper elaborates on the thickness-dependent structural, optical, and electrical properties of Erbium(III)-Tris-8-hydroxyquinolinato (ErQ3) films. The surface morphology reveals the grains that consolidate to make denser films with increasing film thickness. The ErQ3 grain sizes increased from 80 to 187 nm as the thickness increased from 80 to 190 nm. From XRD analysis, the ErQ3 films are partially crystallized with only one peak at 2θ?=?9.80° and a plateau in the range of 20–40°. Electrical measurement of ErQ3 films showed that the electrical conductivity had a strong dependence on film thickness. Transmittance and reflectance measurements showed that the films exhibited a 2.60 eV bandgap, and it does not depend on the thickness of the film. Also, the dispersion of the refractive index was analyzed to determine the essential parameters. The nonlinear optical parameters such as nonlinear refractive index and third-order nonlinear optical susceptibility were calculated by Miller's principles.

     

Spatial and spectral imaging of single micrometer-sized solvent cast fluorescent plasticized poly(vinyl chloride) sensing particles

Microscale plasticized PVC particles doped with hydrophobic ionophores are prepared by solvent evaporation of aqueous suspensions of sensing cocktails (poly(vinyl chloride), plasticizer, active sensing components, and tetrahydrofuran) and tested as particulate microoptical sensors. The particles contain either only the chromoionophore ETH 2458 as active reagent or the potassium ionophore BME-44, chromoionophore ETH 5294, and lipophilic anionic sites NaTFPB. The former system functions according to an anion-hydrogen ion coextraction mechanism and shows a Hofmeister anion selectivity pattern, while the latter sensor containing additional ionophores represents the more complex, truly selective optical sensors based on ion-exchange equilibria. Single microspheres are simultaneously characterized spatially and spectrally by fluorescence microscopy, coupled to a spectrometer equipped with a CCD detector. The results indicate that these microspheres respond in complete analogy to traditional thin-film-based optodes previously reported in the literature. The introduction of small, spherical ionophore-based sensing particles that operate on the basis of bulk extraction principles holds the promise of significantly expanding the available chemical palette of microsphere-based analytical assays.     

9-Acridone-4-carboxylic acid as an efficient Cr(III) fluorescent sensor: trace level detection, estimation and speciation studies

9-Acridone-4-carboxylic acid has been established as an efficient Cr(III) fluorescent sensor. The binding of this ligand with Cr(III) is confirmed by FTIR, thermal and mass spectral analysis of the product. Based on this chelation assisted fluorescence quenching, a highly sensitive spectrofluorometric method is developed for trace level detection, estimation and speciation studies of chromium in DMF-water. The ligand has an excitation and emission maxima at 408 nm and 498.4 nm, respectively. The equilibrium binding constant of the ligand with Cr(III) is 8.1378 × 10(4) as calculated using Stern-Volmer equation. Up to 9 × 10(-6)mol L(-1) of [Cr(3+)], linearity has been observed. The interference of foreign ions has been found to be negligible.     

Effect of annealing temperature on structural,optical and humidity sensing properties of indium tin oxide (ITO) thin films

Tin doped indium oxide (ITO) thin films were prepared by sol–gel spin coating method with In (NO₃)·3H₂O and SnCl₄·5H₂O as indium and tin sources, respectively. The as deposited samples were annealed at various temperature such as, 300, 400, 500 and 600?°C for 2 h in ambient atmosphere. The grown ITO thin films are polycrystalline in nature with cubic structure of In₂O₃ with the space group La3 and the results are in good agreement with the standard JCPDS data (card no#06-0416). In addition crystalline size increases with increasing annealing temperature from 25 to 55 nm. Polycrystalline with uniform smooth surface was observed by SEM micrographs. The optical band gap energy was found to be decreased from 3.85 to 3.23 eV as the annealing temperature is increased from 300 to 600?°C. The humidity sensing performance (high sensitivity and fast response time) was significantly improved for 600?°C thin films samples, which is probably due to smaller energy band gap and physisorption between the water molecules and the surface of the thin films. The films were further characterized by PL and EDS analysis. The effect of temperature on humidity sensing mechanism of ITO thin films is also discussed.     

Growth,structural, optical,DFT, thermal and dielectric studies of N-Benzyl-3-nitroaniline (B3NA): a promising nonlinear optical crystal

The non-linear optical material N-Benzyl-3-nitroaniline was synthesized and grown through an aqueous solution using a low temperature solution growth technique. This conforming monoclinic crystal structure with the P2₁ space group was established by the characterization study of single crystal X-ray diffraction. A powder X-ray diffraction analysis was performed to confirm crystalline nature. As one of the functioning groups of nitro-aniline revealed using the Fourier transform infrared spectrum and the prominent spectral band seen at 3404 cm^?1 is caused by stretching vibrations of the N–H group. The lower cut-off wavelength of the ultra violet-visible absorption and emission spectrum was found to be about 320 nm as the excitation of fluorescence and the emission of blue and red colors are expected at 459 nm and 688 nm. To determine the difference in energy between HOMO and LUMO by 9.6258, using the B3LYP/6-311G++ (d,p) method. The time-based DFT technique was used to calculate the first-order hyperpolarization (β)?=?1.214?×?10^–30 esu. Thermo gravimetric and differential thermal analysis measurements were used to determine the crystal’s moisturing toughness up to 282.87 °C. The relative dielectric constant changes with frequency. Kurtz Perry’s method confirmed 1.66 times the efficiency of second harmonic generation to this present crystal comparing KDP crystal. This data shows that there is a significant amount of promise that is used in optoelectronic materials.