Phosphotungstic acid

About: Phosphotungstic acid is a research topic. Over the lifetime, 1925 publications have been published within this topic receiving 38059 citations. The topic is also known as: Phosphowolframic acid.

Application of standard micro-anatomical staining methods to epoxy resin-embedded sections

Abstract: Staining of semi-thin sections of osmium-fixed epoxy resin (Epon or Araldite)-embedded tissues with haematoxylin and acid dyes as counterstains (eosin or phloxin) was successfully achieved after intense oxidation using hydrogen peroxide as the oxygen donor. Results are closely similar to those obtained with paraffin sections (haematoxylin and eosin): nuclei stain blue, cytoplasm and extracellular structures ( eg , collagen, elastica, basement membranes) stain with varying shades of red. Preliminary studies show that similarly good results, comparable with standard paraffinembedded histological materials, can be obtained, using H 2 O 2 pretreatment, with Weigert9s iron haematoxylin, Mallory9s phosphotungstic acid haematoxylin, Alcian blue, PAS reaction, Sudan III, Sudan black, oil red, Gomori9s aldehyde fuchsin, and Baker9s acid haematein.

Phosphomolybdic and phosphotungstic acids as efficient catalysts for the synthesis of bridged 1,2,4,5-tetraoxanes from β-diketones and hydrogen peroxide.

Abstract: Phosphomolybdic acid (PMA) and phosphotungstic acid (PTA) efficiently catalyze the addition of H2O2 to β-diketones to form bridged 1,2,4,5-tetraoxanes. These reactions are not accompanied by the formation of monocyclic peroxides containing hydroxy and hydroperoxide groups or polymeric peroxides. The use of these catalysts made it possible to obtain bridged tetraoxanes from easily oxidizable benzoylacetone derivatives and α-unsubstituted β-diketones. The syntheses are scaled up to ten grams. The resulting peroxides can be easily isolated from the reaction mixture by column chromatography. The yield of tetraoxanes depends on the structure of β-diketone and varies from 12 to 83%. NMR monitoring of two bridged 1,2,4,5-tetraoxanes synthesis was carried out.

Facile in situ growth of highly dispersed palladium on phosphotungstic-acid-encapsulated MIL-100(Fe) for the degradation of pharmaceuticals and personal care products under visible light

Abstract: A simple, facile in situ reduction approach is reported for the synthesis of Pd-nanoparticle-decorated phosphotungstic acid (PTA)-MIL-100(Fe) nanocomposites (Pd-H3PW12O40-MIL-100(Fe), denoted Pd-PTA-MIL-100(Fe)). During the in situ synthesis, PTA is encapsulated into the matrix of MIL-100(Fe) and serves as a UV-switchable reducing agent, resulting in highly dispersed Pd NPs. Using the photocatalytic degradation of pharmaceuticals and personal care products as model reactions, the ternary Pd-PTA-MIL-100(Fe) hybrids exhibited enhanced photocatalytic activity compared with their foundation matrices, the binary PTA-MIL-100(Fe) nanocomposite. Based on photoelectrochemical analyses, the improved photocatalytic performance can be attributed to the well-known electronic conductivity of the Pd NPs, the fast electron transport of PTA, the intense visible-light absorption of MIL-100(Fe), and the matched energy levels of the three components: MIL-100(Fe), PTA, and Pd NPs. Importantly, almost no Fe and W ions were leached from the samples during the reaction, demonstrating the photostability of the Pd-PTA-MIL-100(Fe) composite. In addition, possible photocatalytic reactions mechanisms have also been investigated.