Preparation and Characterization of Cu Nano-Powders by Hydrothermal Decomposition and Hydrogen Reduction Process

2010 ◽  
Vol 160-162 ◽  
pp. 456-459 ◽  
Author(s):  
Zai Yuan Li ◽  
Yun Gao ◽  
Duo Jin ◽  
Jie Liu ◽  
Yu Chun Zhai
Keyword(s):  
Hydrogen Reduction ◽  
Ph Value ◽  
Raw Materials ◽  
Reduction Process ◽  
Powder Size ◽  
Reaction Conditions ◽  
Nano Powder ◽  
Circular System ◽  
Reaction Speed

In this paper, Cu nano-powder was used to reduce CuO nano-powder by hydrogen reduction process, which was prepared by hydrothermal decomposition method taken CuSO4•5H2O and NaOH as raw materials. The reaction conditions of CuO nano-stick were that concentration of CuSO4 liquor was 0.1mol•L-1, concentration of NaOH liquor was 5mol•L-1, dropping speed was 50ml•min-1, pH value of reacting terminal was 12, stirring speed was 1200 r•min-1, reacting temperature was 60°C, reacting time was 30min. The CuO stick longness was 200nm, diameter was 30nm. The reaction conditions of CuO nano-boll were that dropping speed was 50ml•min-1, pH value of reacting terminal was 7, stirring speed 100 r•min-1, reacting temperature was 80°C, reacting time 30min. The diameter of CuO nano-ball was 50~100 nm. The Cu powder was prepared with materials CuO tick by hydrogen reduction in closed circular system. The higher the temperature, the reaction speed is faster. Hydrogen reduction time was 400s in reacting temperature 240°C. The Cu powder’ size was less than 100nm.

Preparation and Characterization of Ni90Ag10 Composite Nano-Powders by Chemical Co-Precipitation Hydrogen Reducing

2010 ◽  
Vol 160-162 ◽  
pp. 460-463
Author(s):  
Zai Yuan Li ◽  
Yun Gao ◽  
Duo Jin ◽  
Jie Liu ◽  
Yu Chun Zhai
Keyword(s):  
Hydrogen Reduction ◽  
Ph Value ◽  
Solution Concentration ◽  
Precipitation Method ◽  
Composite Powders ◽  
Reaction Conditions ◽  
Naoh Solution ◽  
Circular System ◽  
Co Precipitation

The Ni(OH)2-Ag2O powders were prepared with materials NaOH, NiNO3•6H2O and AgNO3 by chemical co-precipitation method. The reaction conditions were that Ni2+ solution concentration 0.0943mol•L-1 and Ag+ solution concentration 0.0943mol•L-1 in the Ni2+-Ag+ composite solution concentration, the NaOH solution concentration 4mol•L-1, dropping speed of the NaOH solution 50ml•min-1, the pH value of reacting terminal 13, the stirring speed 1200r•min-1, the reacting temperature 25°C, the reacting time 60min. Ni(OH)2-Ag2O composite powders’ size was 2-50nm. Ni-Ag composite powders were prepared with materials Ni(OH)2-Ag2O composite powders by hydrogen reduction in closed circular system. Ni-Ag composite powders’ size was 2-40 nm.

Preparation and Characterization of Fe90Ni6Cu4 Alloy Powders

2011 ◽  
Vol 233-235 ◽  
pp. 930-933
Author(s):  
Zai Yuan Li ◽  
Myongil Pang ◽  
Yu Chun Zhai
Keyword(s):  
Hydrogen Reduction ◽  
Ph Value ◽  
Raw Materials ◽  
Solution Concentration ◽  
Precursor Powder ◽  
Powder Particle Size ◽  
Naoh Solution ◽  
Co Precipitation ◽  
Precursor Powders

The Fe90Ni6Cu4 precursor powder was prepared by chemical co-precipitation taken FeSO4·7H2O, NiSO4·6H2O, CuSO4·5H2O and NaOH as raw materials. The Fe90Ni6Cu4 precursor powder shape was majority stick, its diameter was about 10nm, length was about 100nm. The reaction conditions were that concentration of Fe2+, Ni2+and Cu2+mix solution was 0.1mol·L-1, NaOH solution concentration was 4 mol·L-1, the dropping rate of NaOH solution was 50 ml·min-1, the reaction temperature was 30°C, the pH value of the reaction end was 11, the stirring rate was 1200 r·min-1. The Fe90Ni6Cu4 alloy powders were obtained through hydrogen reduction of the Fe90Ni6Cu4 precursor powders. When the hydrogen reduction temperatures lower, it’s the reaction speed slower. When the reduction temperature was 800°C, the restore time needed to the 1200sec. The Fe90Ni6Cu4 alloy powder particle’ size was 200-500 nm.

scholarly journals A Novel Process for the Synthesis of NaV2O5 Mesocrystals from Alkaline-Stripped Vanadium Solution via the Hydrothermal Hydrogen Reduction Method

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 271
Author(s):  
Guobin Zhang ◽  
Yimin Zhang ◽  
Shenxu Bao ◽  
Liuhong Zhang
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Reduction ◽  
Ph Value ◽  
Hydrothermal Process ◽  
Reduction Process ◽  
Oriented Attachment ◽  
Synthesis Process ◽  
Synthesis Mechanism ◽  
Time Saving ◽  
Synthesis Time

NaV2O5 mesocrystals were successfully synthesized from an alkaline-stripped pentavalent vanadium solution through a novel hydrothermal hydrogen reduction process. The optimal conditions for the hydrogen partial pressure, reaction temperature, initial solution pH value, and reaction time for the pure-phase NaV2O5 synthesis were ascertained to be 4 MPa, 200 °C, 4.0, and 2 h, respectively. The synthesis time (only 2 h) was greatly shortened, by nine times, compared with the most time-saving (18 h) hydrothermal process at present. X-ray diffraction (XRD) analysis revealed that the as-prepared powders demonstrated a typical layered orthorhombic structure of NaV2O5. The purity of the as-prepared NaV2O5 reached up to 99.98%. An electrochemical test showed that the as-prepared NaV2O5 has a potential application in sodium ion batteries. According to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the as-prepared NaV2O5 powders were identified to have rod-like mesocrystals consisting of small rods which preferentially grow along the (010) direction. Furthermore, the phase transformation mechanism and crystal growth mechanism in NaV2O5 preparation were discussed systematically, based on which the synthesis mechanism of NaV2O5 was proposed as pentavalent vanadates pre-sedimentation, hydrogen reduction with dehydration, sodium ions insertion, and finally self-assembly oriented attachment. The synthesis process is characterized as time-saving and low-cost, and thus it may have great application prospects.

Synthesis and Characterization of Liquefied Corn Barn-Based Epoxy Resins

2011 ◽  
Vol 236-238 ◽  
pp. 116-119
Author(s):  
Wen Ming Zhang ◽  
Yu Cang Zhang ◽  
De Feng Zhao
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
Raw Materials ◽  
Thermal And Mechanical Properties ◽  
Reaction Conditions ◽  
Good Thermal Stability ◽  
Molecular Weights ◽  
Biomass Materials ◽  
Adhesive Shear Strength

The liquefied corn barn-based epoxy resin (LCBER) was synthesised through the glycidyl etherification reaction from liquefied corn barn (LCB) had having groups of bound phenol and epichlorohydrine under alkali conditions. The average molecular weights of LCBER in various reaction conditions were examined. The extreme high molecular weight portion of LCBER-30 was obtained using LCB at 30 min as raw materials. The epoxy functionality of LCBER was controlled by the amount of bound phenol in LCB. LCBER was cured with polyamide-650 (PA-650) and the thermal and mechanical properties were evaluated. Comparing to the petroleum-based bisphenol-A type epoxy resin (DGEBA), LCBER presented higher adhesive shear strength and good thermal stability. These suggested that LCBER would be more suitable to glue biomass materials.

The Influence of Calcium Additive in the Structural Formation of Tungsten via Reduction Reaction

2015 ◽  
Vol 1088 ◽  
pp. 159-163
Author(s):  
Xin Yang ◽  
Dun Qiang Tan ◽  
Ya Lei Li ◽  
Wen He ◽  
Hong Bo Zhu ◽  
...  
Keyword(s):  
Hydrogen Reduction ◽  
Raw Materials ◽  
Tungsten Powder ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Structural Formation ◽  
Powder Particles ◽  
Micro Morphology ◽  
Existing Form ◽  
Solution Doping

With the processes of solution doping and hydrogen reduction process, the raw materials APT powder was converted into the tungsten with calcium additive. Micro-morphology, micro-structure, the existing form of element calcium and their distribution were examined by SEM, HRTEM and EDS. The results show that Element calcium is mainly in the form of CaWO4in tungsten oxide powder and has two calcium tungstate forms which are CaWO4and Ca4.26W10O30in reducing tungsten powder. The Ca-W-O particles are embedding in the tungsten powder particles; the rest distribute between the tungsten powder particles.

Synthesis and Characterization of Zn-Ca-Mg-Al Hydrotacite-Like Compounds and its Application in the PVC

2011 ◽  
Vol 66-68 ◽  
pp. 65-69
Author(s):  
Long Feng Li ◽  
Yuan Gao ◽  
Mao Lin Zhang
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Treatment Temperature ◽  
Molar Ratio ◽  
Medium Ph ◽  
X Ray ◽  
Ft Ir ◽  
Thermal Stability Of

Ca-Mg-Al hydrotalcite-like compounds (CaMgAl-HTLcs) were synthesized by a hydrothermal method, and characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and differential thermal analysis (DTA) techniques. The effects of the medium pH value, the molar ratio of the raw materials, the reaction temperature and the reaction time on the structure of CaMgAl-HTLcs were studied. The results showed that increasing treatment temperature and reaction time could improve the crystallinity and monodispersity of hydrotalcite-like compound particles. And well-defined CaMgAl-HTLcs could be prepared at a pH value of 10~11 with n(Zn+Mg+Ca):n(Al) =2. The products synthesized were applied to PVC to improve the thermal stability of PVC.

Characterization and Application in Pretreatment of Landfill Leachate on Modified Bentonites

2011 ◽  
Vol 287-290 ◽  
pp. 1675-1679
Author(s):  
Hong Shao ◽  
Ning Cao
Keyword(s):  
Landfill Leachate ◽  
Raw Materials ◽  
Removal Rate ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Cod Removal Rate ◽  
Organic Bentonite ◽  
Better Than

A series of sodium bentonites and cetyl tri methyl ammonium bromide as raw materials were prepared to the modified organic composite montmorillonites. The performance characterization of the modified organic bentonite was observed by means of IR spectroscopy, X-ray diffraction, scanning electron microscopy. And the modified organic bentonite was applied into the pretreatment of landfill leachate, which was with the COD as high as 20000-37000 mg/L. The COD removal rate was invested as index. The optimum dosage and the best reaction conditions of bentonite have also been studied. The results indicated that the treatment effect of COD on the modified bentonite was better than the natural bentonite. Under the optimum conditions, the removal rate of COD reached 67.85% and the load of biological treatment was reduced on the next step.

Preparation and Characterization of Cu-Coated Nano SiC Composite Particles

2008 ◽  
Vol 373-374 ◽  
pp. 674-677 ◽  
Author(s):  
Sheng Zhu ◽  
Chao Li ◽  
Jian Hua Du ◽  
Wen Zheng Han
Keyword(s):  
Reaction Mechanism ◽  
Heterogeneous Nucleation ◽  
Oxidation Rate ◽  
Ph Value ◽  
Composite Particles ◽  
Nucleation Process ◽  
Sic Particles ◽  
Reaction Solution ◽  
Reaction Speed

The Cu-coated nano SiC composite particles were prepared by heterogeneous nucleation method. For the heterogeneous nucleation process, the dispered nano SiC particles and the active Cu2O precipitation were both prefabricated. The composite particles were characterized by means of XRD, SEM, EDS, TEM and ED analysis technics. It is found that Cu layers are coated on the nano SiC particles, which are continuous and dense, and partly oxidized to Cu2O, and the oxidation rate can be reduced by improving experimental processes. The investigation on reaction mechanism shows the disproportionating reaction speed of Cu+ can be controlled by adjusting the pH value of reaction solution, which makes the degree of supersaturation of Cu crystallites accord with the conditions of heterogeneous nucleation.

Preparation of Sulfonated Cyclohexanone-Formaldehyde Resin

2013 ◽  
Vol 364 ◽  
pp. 701-705 ◽  
Author(s):  
Hong Xia Guo ◽  
Qiang Liu ◽  
Zi Ming Wang ◽  
Su Ping Cui
Keyword(s):  
Molecular Weight ◽  
13C Nmr ◽  
Ph Value ◽  
Sodium Sulfite ◽  
Raw Materials ◽  
Average Molecular Weight ◽  
Formaldehyde Resin ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
Optimum Reaction

Sulfonated cyclohexanone-formaldehyde resin (SCF) was synthesized using cyclohexanone and formaldehyde as raw materials, sodium sulfite as sulfonating agent. The composition of the SCF resin was characterized by FTIR and 13C NMR, and the possible mechanism for formation of the resin was suggested. The effects of reaction parameters, such as ratio of formaldehyde and cyclohexanone, the amount of sulfonating agent, as well as reaction temperature and pH, on the viscosity and average molecular weight were investigated. The results showed that the optimum reaction conditions was that the ratio of reactant was n (formaldehyde):n (cyclohexanone):n (sodium sulfite) = 2.0:1.0:0.7, and pH value of the system was 10 at 90°C temperature. The average molecular weight of the resulted resin was 58392.

scholarly journals Production and Characterization of a Novel Low-Sugar Beverage from Red Jujube Fruits and Bamboo Shoots Fermented with Selected Lactiplantibacillus plantarum

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1439
Author(s):  
Chu-Min Zhao ◽  
Ting Du ◽  
Ping Li ◽  
Xin-Jun Du ◽  
Shuo Wang
Keyword(s):  
Antioxidant Capacity ◽  
Nutritional Value ◽  
Ph Value ◽  
Raw Materials ◽  
High Yield ◽  
Total Phenolic ◽  
Fermentation Products ◽  
Bamboo Shoots ◽  
Different Strains

Red jujube fruits and bamboo shoots are rich in many nutrients and have the advantage of high yield in China. However, the storage of fresh fruits is difficult, and there are no fermented products using both as raw materials. In order to develop the two raw materials into novel products and improve their nutritional value, this study reports the production and characterization of a beverage via fermentation of red jujube fruits and bamboo shoots with Lactiplantibacillus plantarum. L. plantarum TUST-232 was selected as the starter from several different strains by comparing pH value and the number of viable cells, which reached 8.91 log CFU/mL in the beverage fermented for 14 h at 37 °C with 0.3% inoculation. After fermentation, the beverage showed improvement in the contents of several nutrients and antioxidant indices, with a decrease of 44.10% in sucrose content, along with increases of 11.09%, 12.30%, and 59.80% in total phenolic content, total antioxidant capacity, and superoxide anion scavenging ability, respectively. These results indicate that L. plantarum fermentation of red jujube fruits and bamboo shoots could be an effective way to develop a new beverage with high nutritional value, high antioxidant capacity, and high dietary fiber content. This research provided experimental support for the development of new fermentation products with the functions of improving health and body functions.

Sign in / Sign up

Export Citation Format

Share Document