Sodium hypophosphite

About: Sodium hypophosphite is a research topic. Over the lifetime, 1695 publications have been published within this topic receiving 15932 citations.

Durable press finishing of cotton fabrics

Abstract: Polycarboxylic acid finishing of cotton fabrics was studied.In order to eliminate the effect of formaldehyde released by DP finishing,and reduce the yellowness caused by high temperature curing and phosphorus content in wastewater,DP finishing of cotton fabrics was performed with mixed citric acid and tartaric acid as finishing agent,and the effects of mass fraction of citric acid and tartaric acid,curing conditions,kinds and concentration of catalyst,and mass concentration of additives on the treatment were investigated.The experiment demonstrated that the optimum finishing results are obtained when mass fraction of citric acid to tartaric acid is 1∶ 1,curing temperature is 180 ℃,curing time is 2 min,mass concentration of nanosilica is 2 g /L,mass concentration of sodium hypophosphite is 20 g /L,and mass concentration of softener LD-5030 is 20 g /L.

Role of Substrate in Au Nanoparticle Decoration by Electroless Deposition

Abstract: Decoration of nanostructures is a promising way of improving performances of nanomaterials. In particular, decoration with Au nanoparticles is considerably efficient in sensing and catalysis applications. Here, the mechanism of decoration with Au nanoparticles by means of low-cost electroless deposition (ELD) is investigated on different substrates, demonstrating largely different outcomes. ELD solution with Au potassium cyanide and sodium hypophosphite, at constant temperature (80 °C) and pH (7.5), is used to decorate by immersion metal (Ni) or semiconductor (Si, NiO) substrates, as well as NiO nanowalls. All substrates were pre-treated with a hydrazine hydrate bath. Scanning electron microscopy and Rutherford backscattering spectrometry were used to quantitatively analyze the amount, shape and size of deposited Au. Au nanoparticle decoration by ELD is greatly affected by the substrates, leading to a fast film deposition onto metallic substrate, or to a slow cluster (50–200 nm sized) formation on semiconducting substrate. Size and density of resulting Au clusters strongly depend on substrate material and morphology. Au ELD is shown to proceed through a galvanic displacement on Ni substrate, and it can be modeled with a local cell mechanism widely affected by the substrate conductivity at surface. These data are presented and discussed, allowing for cheap and reproducible Au nanoparticle decoration on several substrates.

Electroless deposition of nickel coatings and depositing baths therefor

Abstract: The electroless deposition of nickel coatings on metals and metal alloy is accomplished with aqueous baths which contain 10-50 g/l of a fluorine-containing nickel compound; 40 to 200 g/l diammonium hydrogen citrate; 20 to 100 g/l ammonium hydrogen difluoride; 5 to 50 g/l 2-hydroxy-4-methyl benzoic acid, (2,4-cresotinic acid); 0.0005-0.05 g/l copper salt; and 10-100 g/l sodium hypophosphite. Nickel fluoride and nickel (II)-hydroxide carbonate dissolved in hydrofluoric acid have been found particularly advantageous. Smooth and uniform, corrosion-resistant coatings are obtained also on complicated formed parts of magnesium and magnesium alloys.

無電解Ni-Cu-P合金めっき皮膜の電気抵抗特性

Abstract: The electric resistance behavior and the structure of electroless nickel-copper-phosphorus alloy films obtained from various kinds of plating baths containing sodium hypophosphite as a reducing agent were investigated by means of an X-ray diffraction method, a film resistance measurement, and a differential scanning carolimetry. It was found that resistivity of films as-plated became constant value more than 1-2μm thickness, and it became smaller when the contained the larger content of copper. For change of resistivity of films by the heat treatment, the ratio of its decrease became larger when the films contained the larger content of phosphorus and its relation corresponded well to the structural variation of films. For the films deposited from caustic alkaline citrate bath, the returning of films became worse, when content of copper incresed. The heat treatment at 300°C 1hr. in vacuum, however, developed its returning. In case of ammonia alkaline citrate bath, the returning of films were better than that deposited from caustic alkaline citrate bath. In all films asplated, the resulting temperature coefficient of resistance (TCR) were lower with decreasing the grain size of film and TCR were larger by the heat treatment.

Efficient photocatalytic-water-splitting hydrogen production catalyst and preparation method thereof

Abstract: The invention discloses a copper phosphide and titanium dioxide nanocrystalline compound-type photocatalytic-water-splitting hydrogen production catalyst and a preparation method thereof, and belongs to the technical field of nano-catalysts. The preparation method includes the steps that copper nitrate is prepared into copper hydroxide, copper hydroxide and sodium hypophosphite are calcined at certain temperature and under nitrogen protection, and then a product is rinsed, centrifuged and dried to obtain product copper phosphide; then, copper phosphide and anatase titanium dioxide nanocrystals are mixed and ground evenly to obtain the catalyst through preparation. The reaction rate of photocatalytic-water-splitting hydrogen production can be increased to 7.94 mmol h g from 0.74 mmol h g of pure titanium dioxide, and is increased by over 10 times. In this way, the catalyst is used as a new technological means for solving energy crisis, having potential industry applicability and producing environmentally-friendly novel energy.