Chemically-Induced Graft Copolymerization of Diethylenetriamine onto Bagasse Celluloses

2011 ◽  
Vol 295-297 ◽  
pp. 1494-1498
Author(s):  
Nan Nan Xia ◽  
Hong Xiang Zhu ◽  
Shuang Fei Wang ◽  
Ying Xiao Mu ◽  
Chao Bing Deng ◽  
...  
Keyword(s):  
Reaction Time ◽  
Aqueous Medium ◽  
Reaction Temperature ◽  
Graft Copolymerization ◽  
Optimum Process ◽  
Process Conditions ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Chemically Induced ◽  
Ft Ir

Graft copolymerization of diethylenetriamine onto bagasse celluloses was investigated with ammonium ceric nitrate as initiator in an aqueous medium. The condition of the graft copolymerization initiator concentration, the mass ratio of monomer/cellulose, reaction temperature, reaction time based on the experiment is optimized according to the zeta potential. The results showed the relative optimum process conditions were: the concentration of initiator at 36.98mmol/L, the mass ratio of the monomer and cellulose at 1:1, the reaction temperature at 70°C, and the reaction time by 3h. In addition, the graft copolymers were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction analysis (XRD). The results showed that bagasse celluloses could be grafted with diethylenetriamine in aqueous medium.

scholarly journals Extraction of alumina from alumina rich coal gangue by a hydro-chemical process

2020 ◽  
Vol 7 (4) ◽  
pp. 192132 ◽  
Author(s):  
Quancheng Yang ◽  
Fan Zhang ◽  
Xingjian Deng ◽  
Hongchen Guo ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Chemical Process ◽  
Energy Dispersive Spectrometer ◽  
Coal Gangue ◽  
Added Value ◽  
High Alumina ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray

Vast quantities of gangue from coal mining and processing have accumulated over the years and caused significant economic and environmental problems in China. For high added-value utilization of alumina rich coal gangue (ARCG), a mild hydro-chemical process was investigated to extract alumina. The influences of NaOH concentration, mass ratio of alkali to gangue, reaction temperature and reaction time were systematically studied. An alumina extraction rate of 94.68% was achieved at the condition of NaOH concentration 47.5%, alkali to gangue ratio of 6, reaction temperature of 260°C and reaction time of 120 min. The obtained leaching residues were characterized through X-ray diffraction, scanning electron microscopy and energy-dispersive spectrometer. Research confirmed that kaolinite the main alumina-bearing phase of ARCG can be decomposed and transformed to Na 8 Al 6 Si 6 O 24 (OH) 2 (H 2 O) 2 and Ca 2 Al 2 SiO 6 (OH) 2 at relatively low temperature and short reaction time. Additionally, Na 8 Al 6 Si 6 O 24 (OH) 2 (H 2 O) 2 and Ca 2 Al 2 SiO 6 (OH) 2 are unstable and will transform to alumina-free phase NaCaHSiO 4 under the optimal conditions, which is the major reason for high alumina extraction rates.

scholarly journals Synthesis and characterization of thiourea

2019 ◽  
Vol 21 (3) ◽  
pp. 35-39
Author(s):  
Chuanbo Dai ◽  
Hongyu Zhang ◽  
Ruiduan Li ◽  
Haifeng Zou
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Raw Materials ◽  
High Yield ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Step Method ◽  
Lawesson’S Reagent ◽  
One Step ◽  
Lawesson's Reagent

Abstract Herein, a simple and effective method for the preparation of thiourea using a nucleophilic substitution reaction is reported. Urea and Lawesson’s reagent were used as the raw materials to prepare thiourea via a one-step method involving the sulfuration reaction, and the reaction mechanism was analyzed. The effect of the reaction time, reaction temperature, and mass ratio of the raw materials on the yield of thiourea were investigated.The most beneficial conditions used for the reaction were determined to be: Reaction time = 3.5 h, reaction temperature = 75°C, and mass ratio of urea to Lawesson’s reagent = 2:1. Under these optimal conditions, the average yield of thiourea over five replicate experiments was 62.37%. Characterization using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) showed that the as-synthesized substance was thiourea. Our synthetic method has the advantages of high yield, mild reaction conditions and simplicity.

Taguchi Approach and ANOVA in Optimization of the Dissolution of Colemanite in CO2 and SO2- Water Systems

2020 ◽  
Vol 10 (2) ◽  
pp. 88-97
Author(s):  
Zafer Ekinci ◽  
Esref Kurdal ◽  
Meltem Kizilca Coruh
Keyword(s):  
Particle Size ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Gas Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Process Conditions ◽  
Liquid Ratio ◽  
Positive Effects ◽  
Controllable Factors

Background: Turkey is approximately 72% of the world’s boron sources. Colemanite, tincal, ulexite and pandermite are among the most significant in Turkey. Boron compounds and minerals are widely used in many industrial fields. Objective: The main purpose of this study was to investigate the control of impurities in the boric acid production process using colemanite by carrying out the reaction with a mixture of CO2 and SO2 - water, and determining the appropriate process conditions to develop a new process as an alternative to the use of sulfuric acid. Due to worrying environmental problems, intensive studies are being carried out globally to reduce the amount of CO2 and SO2 gases released to the atmosphere. Methods: The Taguchi method is an experimental design method that minimizes the product and process variability by selecting the most appropriate combination of the levels of controllable factors compared to uncontrollable factors. Results: It was evaluated the effects of parameters such as reaction temperature, solid-to liquid ratio, SO2/CO2 gas flow rate, particle size, stirring speed and reaction time. The optimum conditions determined to be reaction temperature of 45°C; a solid–liquid ratio of 0.083 g.mL−1; an SO2/CO2 ratio of 2/2 mL.s−1; a particle size of -0.354+0 .210 mm; a mixing speed of 750 rpm and a reaction time of 20 min. Conclusion: Under optimum operating conditions, 96.8% of colemanite was dissolved. It is thought that the industrial application of this study will have positive effects on the greenhouse effect by contributing to the reduction of CO2 and SO2 emissions that cause global warming.

Application of Box–Behnken design for modeling of lead adsorption onto unmodified and NaCl-modified zeolite NaA obtained from biosilica

2016 ◽  
Vol 75 (2) ◽  
pp. 358-365 ◽  
Author(s):  
Pinar Terzioğlu ◽  
Sevil Yücel ◽  
Mehmet Öztürk
Keyword(s):  
Optimum Process ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Lead Adsorption ◽  
Box Behnken Design ◽  
Lack Of Fit ◽  
Adsorption Capacities ◽  
Zeolite Naa ◽  
Wheat Husk

The main objective of the present study was to optimize lead adsorption onto zeolite NaA. For this purpose, to synthesize zeolite NaA under hydrothermal conditions, local wheat husk was precleaned with chemical treatment using hydrochloric acid solution. The unmodified (ZU) and NaCl-modified (ZN) zeolites were characterized by Brunauer–Emmett–Teller, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray diffraction. The optimization of adsorption process was examined using Box–Behnken Experimental Design in response surface methodology by Design Expert Version 7.0.0 (Stat-Ease, USA). The effects of initial lead (II) concentration, temperature, and time were selected as independent variables. Lack of fit test indicates that the quadratic regression model was significant with the high coefficients of determination values for both adsorbents. Optimum process conditions for lead (II) adsorption onto ZU and ZN were found to be 64.40°C and 64.80°C, respectively, and 90.80 min, and 350 mg L−1 initial lead(II) concentration for both adsorbents. Under these conditions, maximum adsorption capacities of ZU and ZN for lead (II) were 293.38 mg g−1 and 321.85 mg g−1, respectively.

Study on Liquefaction of Corncob in Polyhydric Alcohols

2011 ◽  
Vol 183-185 ◽  
pp. 1110-1113
Author(s):  
Yuan Bo Huang ◽  
Yun Wu Zheng ◽  
Hao Feng ◽  
Zhi Feng Zheng ◽  
Ying Zi Jiang
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Number ◽  
Mass Ratio ◽  
Hydroxyl Number ◽  
Catalyst Amount ◽  
Peg 400 ◽  
Polyhydric Alcohols ◽  
Liquid Products

The liquefaction of corncob in polyhydric alcohols was investigated by using sulfuric acid as a catalyst. Results showed that the best liquefaction could be obtained with residue percent of 4.5% under the conditions with the corncob/polyhydric alcohols mass ratio of 1/5, reaction temperature of 150°C, reaction time of 60 min, catalyst amount of 3% (based on the weight of corncob), PEG 400/glycerin mass ratio of 7/3 in the polyhydric alcohols, respectively. The liquefied liquid products had acid number of 18.9 mg KOH/g and hydroxyl number of 616.3mg KOH/g, respectively.

Experimental Study on Combustion Reaction between Silicon and Nitrogen in Transport Bed

2013 ◽  
Vol 860-863 ◽  
pp. 1374-1377
Author(s):  
Shao Wu Yin ◽  
Li Wang ◽  
Li Ge Tong ◽  
Chuan Ping Liu ◽  
Xing Long Zheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Combustion Reaction ◽  
X Ray Diffraction ◽  
Amorphous Silicon Nitride ◽  
X Ray ◽  
Scanning Electron

Combustion reaction between silicon powders and nitrogen in transport bed was studied. The reaction temperature ranged from 1523 to 1653 K, and the reaction time ranged from 0 to 2.7 min. The phase compositions, morphologies and chemical composition of the products were analyzed by X-ray diffraction, scanning electron microscopy and O/N determinater, respectively. The experimental results showed, in the case of silicon powders with particle size of 2.2 μm, the conversion rate of silicon was 61.9% at reaction temperature of 1653 K and reaction time of 2.7min, and the products mainly comprised amorphous silicon nitride powders.

The Synthesis of High Yield Diglycerin Borate

2011 ◽  
Vol 55-57 ◽  
pp. 312-316
Author(s):  
Qi Wang ◽  
Guo Zheng ◽  
Jian Jie Ai ◽  
Xue Jing Wei
Keyword(s):  
Boric Acid ◽  
Reaction Temperature ◽  
Raw Materials ◽  
High Yield ◽  
Optimum Process ◽  
Process Conditions ◽  
Temperature Reaction ◽  
Reaction Conditions ◽  
Reaction Pressure

High yield diglycerin borate(DGB) have been synthesized by the raw materials glycerol and boric acid in this paper. The structure of the products was characterized by FTIR and11B NMR. The yield of the products was discussed by reaction conditions that were material ratio, reaction temperature, reaction pressure etc. and then the optimum process conditions of preparing DGB was decided. In this condition, high yield DGB can be prepared which could reach more than 96%.

Preparation and Characterization of NiO Nanoparticles through Thermal Decomposition of Bis(glycinato)Nickel(II)dihydrate

2012 ◽  
Vol 601 ◽  
pp. 21-25
Author(s):  
Wei Yi Dan ◽  
Jian Fen Li ◽  
Xiang Chen Tu ◽  
Kui Le Jia
Keyword(s):  
Reaction Time ◽  
Fourier Transforms ◽  
Infrared Spectrometry ◽  
Nio Nanoparticles ◽  
X Ray Diffraction ◽  
Fine Crystal ◽  
Transmission Electron ◽  
Mean Size ◽  
Ft Ir

NiO nanoparticles were successfully prepared by decomposing the predecessor bis(glycinato)nickel(II)dihydrate in the presence of oleylamine and triphenylphosphine (TPP), and different approaches including Fourier transforms infrared spectrometry(FT-IR), X-ray diffraction(XRD) and transmission electron microscopy (TEM) were used to characterize the NiO nanoparticles. Meanwhile, the effects of TPP concentration and reaction time on the size and yield of NiO nanoparticles derived from precursors were thoroughly investigated in this paper. The analysis results indicated that the prepared NiO nanoparticles were found spherical in shape and demonstrated weak agglomeration. They had generally high purity and a fine crystal phase of cubic syngony. Furthermore, the effects of the TPP concentration and reaction time on the size and yield of NiO nanoparticles are very crucial, higher concentration of TPP would results in reduction of both the mean size and yield of NiO particles. However both yields and particles size of NiO nanoparticles continuously increased as increasing reaction time, after more than 60 minutes, the size and yield of NiO nanoparticles kept hardly change.

Optimization of Synthesis Process for Sodium Ascorbate

2012 ◽  
Vol 550-553 ◽  
pp. 10-15 ◽  
Author(s):  
Jing Chen Wang ◽  
Feng Xia Cui ◽  
Tao Li
Keyword(s):  
Reaction Time ◽  
Sodium Carbonate ◽  
Reaction Temperature ◽  
Conversion Rate ◽  
Sodium Ascorbate ◽  
Synthesis Process ◽  
Esterification Reaction ◽  
Reaction Yield ◽  
Process Conditions ◽  
Reactant Ratio

With 2-keto-L-gulonic acid(2KLG) and methanol as raw materials, 98% concentrated sulfuric acid as catalyst, the methyl esterification reaction is occurred. Then with sodium carbonate as a transforming agent, a conversion reaction sodium carbonate is obtained. In this experiment, the effects of reaction time, reaction temperature and reactant ratio on conversion rate of sodium ascorbate were studied. The results showed that sodium carbonate as the reactant of lactonization reaction can effectively shorten the reaction time and improve reaction yield. By experiment under the optimum process conditions: the reaction temperature is 65 °C, reaction time is 150 minutes and the molar ratio of 2-keto-L-gu methyl to sodium carbonate is 1:0.6, the conversion rate reaches 98 % and the effect is better than with sodium bicarbonate as transforming agent.

The Influence of the Hydrothermal Conditions on the Morphologies of β-Ni(OH)2

2012 ◽  
Vol 562-564 ◽  
pp. 494-497
Author(s):  
Xiao Ming Fu
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Reaction Time ◽  
Scanning Electron Microscope ◽  
Reaction Temperature ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Low Reaction Temperature ◽  
Scanning Electron

Flower-like β-Ni(OH)2 and nanoflakes have been successfully synthesized with nickel nitrate as nickel source and stronger ammonia water as precipitant via the hydrothermal method. The phase and the morphologies of the samples have been characterized and analyzed by XRD (X-ray diffraction) and SEM (Scanning electron microscope), respectively. XRD shows that the phase of the samples is β-Ni(OH)2. SEM confirms that The low reaction temperature is propitious to the synthesis of flower-like β-Ni(OH)2, and with the increase of the reaction time the nanoflakes of flower-like β-Ni(OH)2 become much thinner. However, The high temperature is in favor of the synthesis of β-Ni(OH)2 nanosflakes, and with the further increase of the reaction temperature.

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