Showing papers on "Sodium hypophosphite published in 2018"

Core–shell PdPb@Pd aerogels with multiply-twinned intermetallic nanostructures: facile synthesis with accelerated gelation kinetics and their enhanced electrocatalytic properties

Abstract: Delicately engineering well-defined noble metal aerogels with favorable structural and compositional features is of vital importance for wide applications. Here, we reported a one-pot and facile method for synthesizing core–shell PdPb@Pd hydrogels/aerogels with multiply-twinned grains and an ordered intermetallic phase using sodium hypophosphite as a multifunctional reducing agent. Due to the accelerated gelation kinetics induced by increased reaction temperature and the specific function of sodium hypophosphite, the formation of hydrogels can be completed within 4 h. Owing to their unique porous structure and favorable geometric and electronic effects, the optimized PdPb@Pd aerogels exhibit enhanced electrochemical performance towards ethylene glycol oxidation with a mass activity of 5.8 times higher than Pd black.

An Eco-Friendly Multifunctional Nano-Finishing of Cellulose/Wool Blends

Abstract: A new approach for an eco-friendly multi-functionalization of cotton/wool (C/W) and viscose/wool (V/W) blended fabrics was investigated. In this study, Ag-nanoparticle (Ag-NP) and/or ZnO-nanoparticle (ZnO-NP) functional agents were incorporated into the finishing bath along with citric acid (CA) or succinic acid (SA) as ester-crosslinking or esterifying agent, and sodium hypophosphite catalyst using the padding technique. The obtained results indicated that the extent of multi-functionalization expressed as antibacterial activity, UV-blocking functionality and wrinkle recovery ability were determined by kind of nanomaterial, nature of carboxylic acid, i.e., bi- or tri-functional and type of substrate. The results also demonstrated that blended fabrics finished with Ag-NP/ZnO-NP/CA/SHP nano-finishing formulation exhibited outstanding durable multi-functional properties even after 10 washing cycles. In addition, the change in surface morphology and the existence of Ag and/or Zn onto the selected V/W fabric surfaces have been confirmed by SEM and EDX analysis respectively.

Modelling of surfactants and chemistry for electroless Ni-P plating

Abstract: In this work, the effects of the chemical formulation in an electroless nickel phosphorus electrolyte on the physical and mechanical performance of the obtained coating were evaluated. The study not only paid particular attention to the concentration and type of surfactant (anionic, cationic and non-ionic) but also investigated the effect of pH and concentration of sodium hypophosphite in the electrolyte. A three-level Box–Behnken factorial design related to response surface methodology was employed to model the effect of the mentioned parameters and optimise the properties of the coating. Two models fitted with experimental data obtained from microhardness and thickness measurement of the Ni-P coatings. The optimum conditions were determined at pH = 5 with 32 g L−1 sodium hypophosphite and 1.5 g L−1 anionic surfactant. According to the derived models, this formulation would give a Ni-P coating with a microhardness of 1080 Hv and a thickness of 23 µm.

Treatment of Cotton by β-Cyclodextrin/Triclosan Inclusion Complex and Factors Affecting Antimicrobial Properties

Abstract: The efficacy of antimicrobial treatment of cotton fabrics depends on various parameters of the coating process, such as the chemical nature and concentration of the antimicrobial agent, the composition of the crosslinking formulation, and the curing temperature. The inclusion complex of triclosan with β-cyclodextrin (βCD) was synthesized and characterized by FTIR, XRD, NMR, Raman, SEM, and TGA. The minimum inhibitory concentration and minimum bactericidal concentration of the complex against Klebsiella pneumoniae and Staphylococcus aureus were compared to those of its precursor. A multifactorial study included an evaluation of the effects of triclosan complexation with β-cyclodextrin, a comparison between the glyoxal and tetracarboxylic acid as crosslinkers, an investigation of the effect of crosslinker and catalyst concentrations, and a comparison of curing at 120°C and 180°C. The cotton was characterized by FTIR-ATR, the micrographs of treated samples were obtained by SEM and the weight add-on was calculated. The bactericidal properties were determined according to AATCC-147. The correlation between the coating process parameters and the antimicrobial efficacy was determined. The optimal combination leading to the highest weight add-on and the antimicrobial coating that was most durable to multiple detergent washes at an elevated temperature was the use of complexed triclosan grafted onto the cotton in the presence of tetracarboxylic acid, followed by curing at 180°C. The curing temperatures were 120°C (P=0.002) and 180°C (P=0.008), catalysts were 1 % and 2 % aluminium sulfate and sodium hypophosphite (P<0.001), and the crosslinkers were 5 % and 10 % glyoxal and butanetetracarboxylic acid (P<0.001); these parameters significantly enhanced the antimicrobial properties of the treated fabrics. The study showed that βCD did not have antimicrobial activity, while the βCD/triclosan-treated textile exhibited potential antimicrobial properties. Overall, the bactericidal activity of fabrics can be enhanced by using βCD/triclosan with 10 % butanetetracarboxylic acid as a cross-linker and 5 % sodium hypophosphite as a catalyst at a curing temperature of 180°C.

Novel cellulose fabric with multifunctional properties through diverse methods of Ag/TiO2/β-cyclodextrin nanocomposites synthesis

Abstract: Multifunctional cotton fabric with excellent antibacterial efficiency and enhanced durable self-cleaning activity was introduced as a novel substrate with potential benefit for hosting various compounds such as drugs and pollutants providing medical and environmental remediation applications. For this purpose, Ag/TiO2/β-cyclodextrin (β-CD) nanocomposites was synthesized and deposited on cotton fabric using three different methods namely exhaustion, pad-dry-cure and in-situ synthesis, following by post-treatment with citric acid and sodium hypophosphite. The samples were analyzed by different characterization tests including FESEM, EDX, XRD and FTIR. Response surface methodology based on one factor design was applied to study the influence of β-CD:Ag+ molar ratio and treatment method on self-cleaning activity, obtaining the optimized condition. Exhaustion method was found as the best technique providing maximum nanocomposites adsorption and self-cleaning properties based on statistical analysis. The optimized sample possessed enhanced self-cleaning properties toward methylene blue degradation, excellent antibacterial activity against Staphylococcus aureus, maximum chrome ion adsorption, slightly increased tensile strength and crease recovery angle.

Synthesis of MA/AA/MA-β-CD/SHP Quadripolymer and Its Performance Evaluation as Scale Inhibitor

Abstract: A new scale inhibitor MA/AA/MA-β-CD/SHP was prepared from maleic anhydride, acrylic acid, sodium hypophosphite, and MA-β-CD via the method of free radical polymerization in aqueous solution. The MA-β-CD was obtained through the modification of β-cyclodextrin (β-CD) with maleic anhydride (MA). Results of performance evaluation showed that the synthesized copolymer has excellent scale inhibition effect for the calcium scale, and the resistance rate of silicon scale up to 79.81%. The structure, thermal property, and morphology of the copolymer were characterized by FTIR, TGA, and SEM. From crystallization data and morphology of the scale crystals it was found that the copolymer scale inhibitor can make the crystal lattice distortion, and has a good dispersing ability after addition of the scale inhibitor.

Intense Femtosecond Laser-Mediated Electrical Discharge Enables Preparation of Amorphous Nickel Phosphide Nanoparticles.

Abstract: Reported here is a high-efficiency preparation method of amorphous nickel phosphide (Ni–P) nanoparticles by intense femtosecond laser irradiation of nickel sulfate and sodium hypophosphite aqueous solution. The underlying mechanism of the laser-assisted preparation was discussed in terms of the breaking of chemical bond in reactants via highly intense electric field discharge generated by the intense femtosecond laser. The morphology and size of the nanoparticles can be tuned by varying the reaction parameters such as ion concentration, ion molar ratio, laser power, and irradiation time. X-ray diffraction and transmission electron microscopy results demonstrated that the nanoparticles were amorphous. Finally, the thermogravimetric-differential thermal analysis experiment verified that the as-synthesized noncrystalline Ni–P nanoparticles had an excellent catalytic capability toward thermal decomposition of ammonium perchlorate. This strategy of laser-mediated electrical discharge under such an extremely in...

Improvement the Conductivity and Flame Retardant Properties of Carboxylated Single-Walled Carbon Nanotube/Cotton Fabrics Using Citric Acid and Sodium Hypophosphite

Abstract: Improvement of existing properties and creation of new material properties are the most important reasons for increasing industrial uses of cotton fabrics. In this research work, carboxylated single-walled carbon nanotubes (CSWCNT) were stabilized by different methods on a cotton fabric surface, using citric acid (CA) as a cross-linking agent and sodium hypophosphite (SHP) as a catalyst. A scanning electron microscope, electrical resistivity equipment, reflective spectrophotometer has been applied to investigate the influence of carboxylated single-walled carbon nanotube on the performance of the cotton fabrics. Also the flammability of cotton fabric modified by CSWCNT, CA, and SHP was evaluated by measuring the percentage of char yield. The test results were compared and discussed.

Fabrication of oxidation-resistant submicron copper particles and the conductive ink as well as its sintering behavior on the flexible substrate

Abstract: The submicron copper particles with a mean diameter of 197 nm were obtained using lactic acid as stabilizer and sodium hypophosphite as a mild reducing agent. The obtained Cu particles show a good oxidation resistance owing to the weak reducibility of lactic acid. The screen printable copper ink with a metal loading of 50 wt.% was prepared using the obtained copper particles. The copper films after sintering at 150 °C for 1 h in nitrogen atmosphere exhibit a relatively low resistivity of 1.87 × 10−4 Ω•m. The conductive copper film circuits were successfully fabricated on flexible polyimide (PI) substrate, with which an LED can be lighted up easily.

The influence of iodate ion additions to the bath on the deposition of electroless nickel on mild steel

Abstract: An alkaline hypophosphite bath (0.1 M nickel sulphate, 0.2 M sodium hypophosphite, 0.2 M sodium acetate and 0.1 M malic acid, adjusted to pH 5) was used to produce Ni–P coatings on uncoated and ele...

Graphite nickel plating method

Abstract: The invention provides a graphite nickel plating method. The graphite nickel plating method comprises the steps of adding a graphite matrix into a nickel plating solution, and carrying out a reactionso as to obtain nickel plated graphite, wherein the nickel plating solution comprises the following components by content: 20 g/L to 35 g/L of nickel sulfate hexahydrate, 8 g/L to 30 g/L of lactic acid, 2 g/L to 18 g/L of triethanolamine, 20 g/L to 45 g/L of sodium citrate, 10 g/L to 35 g/L of ammonium chloride, 30 g/L to 45 g/L of sodium hypophosphite, 0.01 mg/L to 0.2 mg/L of L-arginine and 0.1mg/L to 10 mg/L of potassium ferrocyanide, pH is adjusted to be 8 to 9 through aqueous ammonia, and the temperature of the nickel plating solution is 30 DEG C to 45 DEG C. According to the graphite nickel plating method, complex technologies like surface degreasing, sensitization, metal palladium activation and peptization are eliminated, so that production efficiency is greatly improved; preciousmetal catalysis is not utilized, so that cost is reduced; and further, graphite powder is firstly subjected to copper plating and then is subjected to nickel plating, so that graphite powder has better electrical conductivity and tensile strength.

Method for chemically plating Ni-P-graphene composite coating on surface of red copper

Abstract: The invention provides a method for chemically plating a Ni-P-graphene composite coating on the surface of red copper The method comprises the steps of removing oil by adopting chemical degreasing liquid which is prepared from the following components: 10 to 30 g/L of sodium hydroxide, 5 to 20 g/L of sodium silicate, 10 to 30 g/L of sodium carbonate and 10 to 30 g/L of trisodium phosphate; then chemically plating by adopting composite plating liquid which is prepared from the following components: 20 to 50 g/L of nickel salt, 20 to 50 g/L sodium hypophosphite, 10 to 40 g/L of sodium acetate,1 to 10 g/L of malic acid, 5 to 20 ml/L of lactic acid, 01 to 10 g/L of surfactant, 1 to 10 mg/L of potassium iodate and 01 to 20 g/L of oxidized graphene in the step (A) The Ni-P-graphene composite coating formed on the surface of the red copper has the advantages of excellent corrosion resistance and high rigidity

Copper phosphide modified titanium dioxide photoelectrode and preparation method thereof and application in photoelectric catalytic decomposition of water

Abstract: The invention relates to a preparation method of a copper phosphide modified titanium dioxide photoelectrode. The preparation method comprises the steps that (1) an alkali solution is added to a copper sulfate aqueous solution with a concentration of 0.02-0.1mol/L to form Cu(OH)2 precipitate, and then ammonia water is added to the Cu(OH)2 precipitate to form [Cu(NH3)4]2 and complex ions to obtaina blue clear solution; TiO2 photo-anodes are immersed in the blue clear solution, taken out and dried, immersion and drying steps are repeated 0-20 times, and TiO2/Cu(OH)2 electrodes are obtained after drying; and (2) sodium hypophosphite is placed in an upper vent of a tube furnace and maintained at 250-350 DEG C for 1-2 hours, hydrogen phosphide gas generated by the sodium hypophosphite is reacted with TiO2/Cu(OH)2 to obtain TiO2/Cu3P photoelectrode through airflow driving of shielding gas. According to the preparation method of the copper phosphide modified titanium dioxide photoelectrode,Cu3P is attached to the surface of TiO2 to combine to form a p-n joint, photo-generated electrons and electron holes are effectively separated under the action of a built-in electric field, the obtained TiO2/Cu3P photoelectrode is used for photoelectric catalytic decomposition of water, the interfacial oxygen evolution reaction can be effectively promoted, and the photo-hydrogen conversion efficiency is further improved.

Preparation method of phosphorus doped cobalt molybdate hydrogen evolution electrocatalyst and product thereof

Abstract: The invention discloses a preparation method of a phosphorus doped cobalt molybdate hydrogen evolution electrocatalyst and a product, and belongs to the technical field of electro-catalysis hydrogen evolution. The method comprises the following steps: (1) separately adding cobalt chloride hexahydrate, ammonium molybdate tetrahydrate and urea in deionized water, and stirring to form a uniform mixedsolution; (2) transferring the solution prepared in step (1) in a reaction kettle, adding a conductive substrate, and carrying out hydrothermal reaction to obtain beta-phase cobalt molybdate precursor material; (3) placing a sample prepared in step (2) in a tube furnace, and carrying out high-temperature thermal treatment in a nitrogen atmosphere to obtain beta-phase cobalt molybdate; and (4) carrying out phosphating on the sample prepared in step (3) in a nitrogen atmosphere to obtain phosphorus doped cobalt molybdate, wherein a reagent for phosphating is sodium hypophosphite. According to the method, by control over the amount of the sodium hypophosphite and the pyrolysis time, phosphorus is successively blended in crystal lattices of cobalt molybdate, and the prepared catalyst has efficient hydrogen evolution capability in an alkaline solution.

Early-strengthening type composition dispersing agent of cement-based cementitious material

Abstract: The invention discloses an early-strengthening type composition dispersing agent of a cement-based cementitious material. The dispersing agent is prepared by mixing the following components in percentage by weight: 10-15% of alkylolamide ferroaluminum complex, 2-7% of cationic polymer, 0.5-2.0% of a metal ion chelating agent, 15-25% of metal sulfate, and the balance of water, wherein the alkylolamide ferroaluminum complex in the composition is prepared by synthesizing inorganic acid, a chelating agent, ferrous sulfate, aluminum sulfate and alkylolamide; the cationic polymer is prepared by synthesizing polyether macromonomer, cationic micromonomer, acrylamide, a double-bond-containing silane coupling agent, mercaptoethanol, hydrogen peroxide, ammonium persulfate, sodium formaldehyde sulfoxylate, sodium hypophosphite hydrate and caustic soda liquid. With the adoption of the early-strengthening type composition dispersing agent, the early strength of the cement-based cementitious materialcan be obviously improved under low doping quantity and on the premise that the working mobility of the cement-based cementitious material is basically not influenced.

Preparation and Properties of Cross-Linked Regenerated Cellulose Fibers

Abstract: Butane-tetra-carboxylic acid (BTCA) and sodium hypophosphite (SHP) were added into cellulose spinning solution. The cross-linked regenerated cellulose fibers were prepared by spinning the solution into a coagulation bath of distilled water and then cured at high temperature. The optimum conditions were obtained according to the single factor experiments. The properties and structure of the fibers were investigated. FTIR and XRD show that the cross-linked fibers were prepared successfully and the crystal form of the fibers remain the same before and after cross-linked. The results indicate that the regenerated cellulose fibers prepared in this study possess more excellent wrinkle recovery ability and wash durability than those treated by finishing process.

Iron-phosphorous compound modified electrode with electro-catalysis oxygen release performance and preparation method

Abstract: The invention relates to an iron-phosphorous compound modified electrode with electro-catalysis oxygen release performance and a preparation method thereof. The preparation method comprises the following steps that 1, preparation is conducted, specifically, an appropriate quantity of pretreated electrode materials and sodium hypophosphite are weighed, and the electrode materials and the sodium hypophosphite are placed at the two ends of a high-temperature reacting device according to a certain mass ratio; and 2, phosphating is conducted, specifically, heat preservation is conducted for a period of time under the nitrogen atmosphere and the certain temperature condition, and after washing and drying, the iron-phosphorous compound modified electrode with the electro-catalysis oxygen releaseperformance is obtained. According to the iron-phosphorous compound modified electrode with the electro-catalysis oxygen release performance and the preparation method thereof, through the one-step direct low-temperature phosphating method, the iron-phosphorous compound modified electrode is prepared, preparation is easy, needed raw materials are low in price and easy to obtain, and industrial application is easy to achieve; and additionally, compared with the prior art, the prepared iron-phosphorous compound modified electrode has the same stability under the 10M KOH and meanwhile has higherelectrocatalytic activity, and thus industrial production is greatly boosted.

Electrolytic Codeposition of Nickel and Phosphorus from Methanesulfonate Electrolyte

Abstract: The characteristics of Ni–P alloy electrodeposition from a methanesulfonate electrolyte have been investigated. It has been found that the phosphorus content of the alloy increases with increasing the concentration of sodium hypophosphite in the electrolyte and reducing the electrodeposition current density. A mechanism of codeposition of nickel and phosphorus has been suggested. It is shown that phosphorus was formed by electrochemical reduction of hypophosphite anions and their disproportionation at a catalytically active surface of a nickel cathode. It has been shown quantitatively that the most likely path for the formation of phosphorus through the electrochemical mechanism is the direct electrochemical reduction of a hypophosphite anion to atomic phosphorus. The rate of phosphorous formation from hypophosphite anions is dependent on the concentration of hydrogen ions in the near-electrode layer. Therefore, the phosphorus content of the coatings obtained from the methanesulfonate electrolyte is slightly decreased as compared with that from the sulfate electrolyte which exhibits higher buffering properties. It has been revealed that codeposition of nickel and phosphorus reduces the kinetic difficulties of electrochemical reduction of the nickel ions. This might be due to an increased near-electrode concentration of nickel hydroxyl complexes discharging at the cathode, which is the result of an increased near-electrode pH caused by the reactions involving hypophosphite anions and hydrogen ions.

Ultrasonic wave and double complexing agent assisted Ce-Ni-Mo-P/Go chemical composite sedimentation layer and preparation method thereof

Abstract: The invention discloses an ultrasonic wave and double complexing agent assisted Ce-Ni-Mo-P/Go chemical composite sedimentation layer and a preparation method of the ultrasonic wave and double complexing agent assisted Ce-Ni-Mo-P/Go chemical composite sedimentation layer. Low-carbon steel is subjected to ultrasonic assistance in Ce-Ni-Mo-P/Go chemical composite sedimentation liquid, and a Ce-Ni-Mo-P/Go chemical composite sedimentation layer is obtained on the surface of the low-carbon steel. Each liter of composite sedimentation liquid contains nickel sulfate hexahydrate, sodium molybdate, sodium hypophosphite, trisodium citrate, lactic acid, cerium acetate lead, oxidized graphene and lauryl sodium sulfate. The trisodium citrate and lactic acid double complexing agent system is adopted in the formula of fluid preparation, sedimentation of a plating layer can be accelerated, and performance can be improved; and self catalysis and reducibility of rare earth cerium are beneficial to sedimentation reaction of plating solution. According to the composite sedimentation layer prepared through the method, the corrosion resistance, surface hardness, wear resistance and the like of low-carbonsteel can be effectively improved, and the problems of surface cracking, large voidage and the like can be effectively solved.

Whitened red phosphorus with high flame-retardant efficiency and preparation method of whitened red phosphorus

Abstract: The invention relates to the technical field of modification of flame retardant, and provides whitened red phosphorus with high flame-retardant efficiency and a preparation method of the whitened redphosphorus. The preparation method comprises the steps of: adding penetrant and emulsifier into water to form a first solution, adding red phosphorus and an aluminum salt into the first solution to form a second solution, heating the second solution to prepare an emulsifying dispersion system, dissolving sodium hypophosphite in water to obtain a sodium hypophosphite solution, and adding the sodiumhypophosphite solution into the emulsifying dispersion system so as to obtain a third solution and prepare a first coating layer at the moment; adding aluminum sulfate octadecahydrate into water to obtain an aluminum sulfate solution, adding sodium carbonate decahydrate into water to form a sodium carbonate solution, adding the aluminum sulfate solution and sodium carbonate solution into the third solution to form a fourth solution, and conducting aging to obtain a second coating layer; adding a formaldehyde solution into melamine to obtain a melamine-formaldehyde resin prepolymer; and addingrutile titanium dioxide and the melamine-formaldehyde resin prepolymer into the fourth solution to form a fifth solution to obtain the whitened coated red phosphorus. The whitened red phosphorus hasa low addition amount, high flame-retardant efficiency, high whiteness, good moisture absorption and good oxidation resistance.

Scale inhibitor for industrial circulating water treatment and preparation method of scale inhibitor

Abstract: The invention discloses a scale inhibitor for industrial circulating water treatment. The scale inhibitor is characterized by being prepared from the following components in parts by weight: 20-25 parts of poly-aspartic acid, 10-12 parts of sodium salicylate, 8-12 parts of sodium polyacrylate, 8-10 parts of zinc salt, 8-10 parts of molybdate, 5-8 parts of hydrolyzed polymaleic anhydride, 5-8 partsof tolyltriazole and 3-5 parts of an admixture, wherein the admixture is prepared by performing mixing reaction on maleic anhydride, sodium hypophosphite, 2-acrylamido-2-methylpropane sulfonic acid,acrylic acid and hydrogen peroxide according to a proportion of 6 to 1 to 5 to 9 to 8. The scale inhibitor provided by the invention is good in scale inhibition effect and low in cost.