Photocatalytic self-cleaning textile fibers have been created using coaxial electrospinning. This is accomplished by electrospinning cellulose acetate as the core phase and a dispersion of nanocrystalline TiO2, a well-known photocatalyst, in the sheath phase. A simple deacetylation step after the initial electrospinning yields self-cleaning textile fibers. Self-cleaning activity is exhibited at moderate power densities in indoor lighting conditions. Nanofibers created from coaxial electrospinning outperform TiO2 surface-loaded nanofibers obtained by conventional electrospinning. Surface-loaded fibers degrade blue dye stains only to a minimum of 20% of the initial concentration, whereas fibers created by coaxial electrospinning fully degrade stains (in 7−8 h).

/pdf/photocatalytic-self-cleaning-textile-fibers-by-coaxial-705jdblapx.pdf

Photocatalytic Self Cleaning Textile Fibers by Coaxial Electrospinning

Derivative spectrophotometry—recent applications and directions of developments

Titania (TiO2) nanoparticles are widely used, or are under active development, for a range of applications in (photo)catalysis, photovoltaics, enzyme support, energy storage, and photonics. The peptide-directed room-temperature formation of titania nanoparticles can be an attractive alternative to higher-temperature synthetic methods. However, the influence of the peptide primary structure on the titania precipitation activity at room temperature is not well understood. Through the selective binding of phage-displayed 12-mer peptides to TiO2 substrates, we have identified 20 peptides with an affinity for titania. The average numbers of arginine, lysine, and histidine residues present in these 20 peptides were distinctly higher than for the overall peptide-bearing phage library. Synthetic 16-mer versions of four of these peptides (i.e., 12-mer peptides with C-terminal tetrapeptide tags for quantitative spectrophotometry) induced the formation of 8.1–38.7 mol TiO2/mol peptide after exposure for only 10 min ...

Identification and Design of Peptides for the Rapid, High-Yield Formation of Nanoparticulate TiO2 from Aqueous Solutions at Room Temperature

High-performance liquid chromatographic determination of some anthraquinone and naphthoquinone dyes occurring in historical textiles

Determination of the oxidation states of iron in natural waters. A review

Simultaneous determination of manganese and zinc in mixtures using first- and second-derivative spectrophotometry.

Complexation equilibria and spectrophotometric determination of iron(III) with 1-amino-4-hydroxyanthraquinone

The solution equilibria of 2-hydroxynicotinic acid (hyna) complexes with mercury(II) have been studied spectrophotometrically in 50% (v/v) ethanol at 20°C and an ionic strength of 0.1mol dm−3 (NaClO4). Three mercuric complexes are formed in solution in dependence on the acidity of the medium. The basic characteristics of the different complexes are determined and the analytical aspects of the complexation reaction are demonstrated. A critical investigation has also been presented of the solution equilibria and stability of the mixed complex of mercury(II) withhyna and thiosalicylic acid (tsa). The various complex transitions leading to the formation of the 1 : 1 : 1 Hg(tsa)(hyna) ternary complex in solution are investigated. The non-charged mono-ligand complex Hg(hyna) is used for UV-spectrophotometric determination of mercury atpH 4.5–5 (λmax=325nm, ɛ=0.8·104lmol−1cm−1). The system obeyed Beer's law up to 36.1 µg ml−1 of Hg(II). The optimum concentration range (Ringbom) is between 6 and 28.5µg ml−1. Interference caused by a number of ions was masked by the addition of fluoride ions.

Solution equilibria and stability of the complexes of pyridinecarboxylic acids: Complexation reaction of mercury(II) with 2-hydroxynicotinic acid

The spectral absorption and acid-base characteristics of 1-amino-4-hydroxyanthraquinone (AMHA) were studied in water-ethanol media. The composition, molar absorptivities, equilibrium constants and stability constants of the chelates of this reagent with zirconium(IV) have been determined spectrophotometrically in 40%V/V ethanol at 20 °C and an ionic strength of 0.1 M(NaClO4). Graphical logarithmic analysis of the absorbance graphs was used to demonstrate and characterise the complexation equilibria in solution. A simple, rapid, selective and sensitive method for the spectrophotometric determination of trace amounts of zirconium is proposed based on the formation of the Zr(AMHA)2 complex at pH 3.5 (λmax.= 600 nm, Iµ= 1.621 × 104 l mol–1 cm–1). Interference caused by a number of ions was masked by the addition of cyanide ions.

Spectrophotometric study of the complexation equilibria of zirconium(IV) with 1-amino-4-hydroxyanthraquinone and the determination of zirconium

The monothiosalicylate complex of mercury(II) reacts with picolinic acid (PIC) to form a ternary complex which has an absorption maximum at 295 nm in 50%V/V ethanol-water in the pH range 6.3–7.5. Beer's law is obeyed up to a 20.15 µg ml–1 concentration of HgII. The molar absorptivity of the ternary complex is 0.86 m2 mol–1 at 295 nm and the sensitivity for the HgII ion is 5.2 × 10–3µg cm–2 per 0.001 absorbance unit. The composition of the ternary complex is estimated to be Hg(TSA)(PIC). A number of ions which interfere with the determination could be masked by the addition of EDTA or fluoride ions as masking agents. Further information on the complex-forming equilibria and stability of the HgII ternary complex was obtained by potentiometric titrations at 20 ± 0.1 °C and 0.1 M(NaClO4) ionic strength.

Hassan Sedaira

Papers

Simultaneous determination of manganese and zinc in mixtures using first- and second-derivative spectrophotometry.

Complexation equilibria and spectrophotometric determination of iron(III) with 1-amino-4-hydroxyanthraquinone

Solution equilibria and stability of the complexes of pyridinecarboxylic acids: Complexation reaction of mercury(II) with 2-hydroxynicotinic acid

Spectrophotometric study of the complexation equilibria of zirconium(IV) with 1-amino-4-hydroxyanthraquinone and the determination of zirconium

Reaction of mercury(II)-thiosalicylate complex with picolinic acid and ultraviolet spectrophotometric determination of mercury(II)