Preparation and Characterization of Formaldehyde Crosslinked Chitosan

2011 ◽  
Vol 239-242 ◽  
pp. 279-282 ◽  
Author(s):  
Juan Qin Xue ◽  
Jing Xian Li ◽  
Ming Wu ◽  
Wei Wang ◽  
Dong Ni Ma
Keyword(s):  
Reaction Time ◽  
Raw Materials ◽  
Cross Linking ◽  
Crosslinking Reaction ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Crosslinked Chitosan ◽  
Chitosan Resin ◽  
Morphology Changes

Using formaldehyde as a crosslinking reagena novel cross-linked chitosan resin was synthesized by orthogonal. The resin material with good properties of sphericity and acidresistivity can be prepared under the optimal experimental conditions, which are found to be 1:6 for the ratio of chitosan and formaldehyde, 60°C for the temperature, 1 h for the reaction time, 640r/min for the stirring rate and 9 for the pH, and the cross-linking rate under the optimal conditions is 401.86%. SEM shows the surface morphology changes of raw materials and products; IR of the raw materials and products shows that the reaction occurs mainly on the amino and the hydroxyl of chitosan, and TG shows that the crosslinking reaction of chitosan can change its heat resistance.

Preparation and Characterization of ZrO2 Nanopowders for Solid Oxide Fuel Cells

2010 ◽  
Vol 105-106 ◽  
pp. 660-663 ◽  
Author(s):  
Yun Xia Chen ◽  
Xing Yong Gu ◽  
Chun’e Cao ◽  
Yang Huang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Lattice Distortion ◽  
Raw Materials ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Experimental Conditions ◽  
Hydrothermal Temperature ◽  
Grain Sizes ◽  
Xrd And Tem

ZrOCl2•6H2O and Y(NO3)3 were used as raw materials to fabricated Y2O3 stabilized ZrO2(YSZ) nanopowders by hydrothermal method. The addition of Y2O3, different precipitants, different hydrothermal temperatures and times were studied. XRD and TEM were employed to characterize phase compositions, grain sizes and lattice parameters of the as-prepared YSZ nanopowders. The results show that less than 10nm and well crystallized cubic YSZ were obtained under a certain experimental conditions. Different precipitants affect the formation of precursors and final products. The addition of NaOH is benefit to the growth of YSZ crystals with the max grain size and the minimum lattice distortion among the three kinds of precipitants. Amorphous YSZ powders are obtained at lower hydrothermal temperature of 150°Cfor longer treating time of 6h. However, when the hydrothermal temperature is elevated at 180°C, well crystallized YSZ powders are prepared only treated for 2h.

scholarly journals Application of Box-Behnken Design in Optimization of Glucose Production from Oil Palm Empty Fruit Bunch Cellulose

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Satriani Aga Pasma ◽  
Rusli Daik ◽  
Mohamad Yusof Maskat ◽  
Osman Hassan
Keyword(s):  
Reaction Time ◽  
Oil Palm ◽  
Raw Materials ◽  
Glucose Production ◽  
Polynomial Equation ◽  
Empty Fruit Bunch ◽  
Optimal Conditions ◽  
Box Behnken Design ◽  
Order Polynomial ◽  
Validation Experiments

Oil palm empty fruit bunch fiber (OPEFB) is a lignocellulosic waste from palm oil mills. It contains mainly cellulose from which glucose can be derived to serve as raw materials for valuable chemicals such as succinic acid. A three-level Box-Behnken design combined with the canonical and ridge analysis was employed to optimize the process parameters for glucose production from OPEFB cellulose using enzymatic hydrolysis. Organosolv pretreatment was used to extract cellulose from OPEFB using ethanol and water as the solvents. The extracted cellulose was characterized by thermogravimetric analysis, FTIR spectroscopy, and field emission scanning electron microscopy. Hydrolysis parameters including amount of enzyme, amount of cellulose, and reaction time were investigated. The experimental results were fitted with a second-order polynomial equation by a multiple regression analysis and found that more than 97% of the variations could be predicted by the models. Using the ridge analysis, the optimal conditions reaction time found for the production of glucose was 76 hours and 30 min, whereas the optimum amount of enzyme and cellulose was 0.5 mL and 0.9 g, respectively. Under these optimal conditions, the corresponding response value predicted for glucose concentration was 169.34 g/L, which was confirmed by validation experiments.

Study on the Preparation of Chitosan-Based Resin

2010 ◽  
Vol 160-162 ◽  
pp. 1810-1815
Author(s):  
Jing Xian Li ◽  
Juan Qin Xue ◽  
Ming Wu ◽  
Yu Jie Wang ◽  
Wei Bo Mao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Experimental Results ◽  
Raw Material ◽  
Cross Linking ◽  
Reactant Ratio ◽  
Experimental Conditions ◽  
Stirring Rate ◽  
Formaldehyde Crosslinking ◽  
New Type

With chitosan as the raw material, a new type of resin material is synthesized through formaldehyde crosslinking. The effects of the reactant ratio, the reaction temperature, the reaction time, the stirring rate and the system pH on the cross-linking rate are studied in detail. The resin material is then characterized by means of IR. The experimental results show that the reaction occurs mainly on the amino and the hydroxyl of chitosan. The chitosan-based resin material with good properties of sphericity and acidresistivity can be prepared under the optimal experimental conditions, which are found to be 1:5 for the ratio of chitosan and formaldehyde, 60°C for the temperature, 1 h for the reaction time, 440r/min for the stirring rate and 10 for the pH.

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.

Application of Response Surface Methodology for Improving the Yield of 1,5-bis(ptoluenesulfonyl)- 3,7-Dihydroxyoctahydro-1,5-Diazocine

2019 ◽  
Vol 16 (3) ◽  
pp. 398-404 ◽  
Author(s):  
Yang Zou ◽  
Jingyi Fei ◽  
Liangzhe Chen ◽  
Qingfeng Dong ◽  
Houbin Li
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Raw Materials ◽  
Low Cost ◽  
Product Yield ◽  
Synthesis Process ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Simple Method ◽  
Ft Ir

Background: 3,3,7,7-tetrakis (difluoramino) octahydro-1,5-dinitro-1,5-diazocine (HNFX), as an important oxidizer in propellants, has received much attention due to its high density and energy. However, there are many difficulties that need to be solved, such as complex synthetic processes, low product yield, high cost of raw materials and complicated purification. In the synthesis of HNFX, the intermediate named 1,5-bis (p-toluenesulfonyl)-3,7-dihydroxyoctahydro-1, 5-diazocine (gem-diol), is difficult to synthesize. Methods: A simple method was used to synthesize the gem-diol. This prepared gem-diol was characterized by FT-IR, 1H NMR, melting point and mass spectrometry. In order to increase the yield of gem-diol, response surface methodology (RSM) was introduced to optimize experimental conditions. Results: After the establishment of the model, the optimal conditions of synthesis were found to be 9.33h for reaction time, 6.13wt. % for the concentration of NaOH and 1.38:1 for ratio of ECH (p-toluenesulfonamide): TCA (epichlorohydrin). Under the optimal conditions, the experimental value and the predicted value of yield were 22.18% and 22.92%, respectively. Conclusion: 1,5-bis (p-toluenesulfonyl)-3,7-dihydroxyoctahydro-1,5-diazocine (gem-diol) can be synthesized using the low cost of chemical materials, including p-toluenesulfonamide, epichlorohydrin, sodium hydroxide and ethanol. Response surface methodology (RSM) is an effective method to optimize the synthesis process, thereby improving the yield of gem-diol.

scholarly journals Research on the Preparation and Performance of Binary Modified Maltodextrin Water-Reducing Agent

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Jingzhi Wu ◽  
Min Qiao ◽  
Zhifeng Lyu ◽  
Qianping Ran
Keyword(s):  
Reaction Time ◽  
Raw Materials ◽  
Reducing Agent ◽  
Optimal Conditions ◽  
Catalyst Amount ◽  
Dextrose Equivalent ◽  
Ft Ir ◽  
Dispersion Capacity ◽  
Anchoring Groups ◽  
And Performance

Using maltodextrin (MD) of different dextrose equivalent (DE) values, 1,3-propanesultone, and maleic anhydride as raw materials, a novel binary modified maltodextrin (BMMD) was synthesized and further applied as a water-reducing agent. Its structure was characterized by Fourier transform infrared (FT-IR) and UV. The rheological behavior of the sample solution and strengths for concrete were also determined and the adsorption was tested by TOC. The influence of the process parameters to degree of substitution (DS) and the dosage on the fluidity of cement paste were investigated. The results show that the optimal conditions of sulfonation were the MD of DE 15, m (sulfonated agent)/m (MD) of 1.4, the catalyst amount of 1% by mass MD, and the reaction time of 12 h; the optimal conditions of esterification were m (esterified agent)/m (SMD) of 0.6, the reaction temperature of 90°C, and the reaction time of 4 h. The optimal dosages of sulfonated maltodextrin (SMD) and BMMD were 0.475% and 0.45%, respectively. In this dosage, the main dispersion capacity of BMMD attributes to two kinds of anchoring groups (SO3-  &  COO-) and the appropriate molecular weight of MD.

Research on Grafted Chitosan in Heterogeneous System

2011 ◽  
Vol 239-242 ◽  
pp. 3275-3278
Author(s):  
Juan Qin Xue ◽  
Dan Dan Wen ◽  
Wei Bo Mao ◽  
Yun Feng Xue ◽  
Ye Wei Du
Keyword(s):  
Reaction Time ◽  
Solid Phase ◽  
Raw Materials ◽  
Sodium Thiosulfate ◽  
Ammonium Molybdate ◽  
Phase Method ◽  
Cobalt Metal ◽  
Experimental Conditions ◽  
Metallic Salt ◽  
Solid Phase Method

With phthalic anhydride, urea, metallic salt and ammonium molybdate as raw materials, Cobalt metal phthalocyanines is prepared by solid-phase method, and the cobalt metal phthalocyanine is modified by the shun dl-aspartic acid anhydride. In the homogeneous conditions, the effects of the reaction temperature, the reaction time, phthalocyanine dosage and initiator dosage are studied. The experimental results show that the grafting polymerization products with the highest grafted rate can be prepared under the optimal experimental conditions, which are found to be 60°C for the temperature, 3h for the reaction time, 0.08g for the potassium persulfate and sodium thiosulfate. The product is analyzed by means of IR, the results show that the chitosan is grafted successfully, and the reaction may occurs on the amino and the hydroxyl of chitosan.

Study on Preparation of Modified Nano-TiO2 and its Application in Photocatalytic Treatment Wastewater Containing Cd2+

2011 ◽  
Vol 347-353 ◽  
pp. 733-737 ◽  
Author(s):  
Xiao Cai Yu ◽  
Peng Fei Zhu ◽  
Yue Xia Chen ◽  
Jun Wang ◽  
Zong Fu An
Keyword(s):  
Reaction Time ◽  
Ph Value ◽  
Raw Materials ◽  
Removal Rate ◽  
Tetrabutyl Titanate ◽  
Photocatalytic Reaction ◽  
Nano Tio2 ◽  
Experimental Conditions ◽  
Cadmium Ions ◽  
Uv Excitation

Nano-Sn0.25Ti0.75O2 was prepared with hydrothermal method using tetrabutyl titanate as one of the primary raw materials. The products were characterized by XRD and SEM, which revealed that the crystal structure of Sn4+-doped nano-TiO2 is rutile, and the nanoparticles diameter was 14.49nm. Photocatalytic treatment the machining wastewater containing cadmium ions with the UV excitation by Nano-Sn0.25Ti0.75O2 was investigated. The experimental results show that Nano-Sn0.25Ti0.75O2 can be used as photocatalyst to removal Cd2+ from the wastewater effectively with the UV excitation. The wastewater pH value, the initial concentration of Cd2+, the amount of catalyst，the reaction time and other factors affect the efficiency of photocatalytic treatment significantly. The optimization experimental conditions for photocatalytic treatment wastewater containing cadmium ions are as follows, when the concentration of Cd2+ in the wastewater is 20mg/L, amount of Sn0.25Ti0.75O2 is 2g/L, pH in wastewater is 7 and the photocatalytic reaction time is 2h, the removal rate of Cd2+ from the wastewater is up to 98.4%.

Synthesis and Characterization of Modified Chitosan by Graft Polymerization

2011 ◽  
Vol 239-242 ◽  
pp. 2843-2846 ◽  
Author(s):  
Juan Qin Xue ◽  
Yu Jie Wang ◽  
Ye Wei Du ◽  
Yun Feng Xue ◽  
Dan Dan Wen
Keyword(s):  
Reaction Time ◽  
Radical Polymerization ◽  
Graft Copolymer ◽  
Surface Property ◽  
Graft Polymerization ◽  
Synthesis And Characterization ◽  
Experimental Conditions ◽  
Modified Chitosan ◽  
Orthogonal Experiments

In this study, chitosan was modified by acrylamide and acrylonitrile when NaHSO3-K2S2O8as initiator under N2. Chitosan-acrylamide-acrylonitrile ternary graft copolymer was synthesized on the use of radical polymerization mechanism. The optimal experimental conditions for the preparation are obtained by orthogonal experiments: the reaction temperature 65°C, the reaction time 6.5h, the concentration of NaHSO33mmol/L, the concentration of K2S2O84.5mmol/L, and the ratio of m(chitosan):m(acrylamide):m(acrylonitrile) was 1:6:4. Under such conditions, the average graft ratio and the graft efficiency could achieve 852.455% and 85.260% respectively. Chitosan and chitosan-acrylamide-acrylonitrile ternary graft copolymer were then characterized by means of XRD and SEM, and the graft mechanism was explored preliminary as well. The results showed that chitosan was modified successfully by graft polymerization, and the surface property and the strength of the product were also improved obviously.

Development and characterization of enzymatic biosensor based on lipase from porcine pancreas for propylparaben detection

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Leila Snani ◽  
Saida Zougar ◽  
Fatiha Benamia ◽  
Ilhem Ghodbane
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Pancreatic Lipase ◽  
Bovine Serum ◽  
Breast Tumors ◽  
Cross Linking ◽  
Porcine Pancreatic Lipase ◽  
Experimental Conditions ◽  
Content Type

Purpose The purpose of this paper is to study the immobilization of porcine pancreatic lipase (PPL), in an organic matrix by a covalent cross-linking method to sense propylparaben (PP) present in aqueous solution. Design/methodology/approach PPL immobilization was performed by the covalent cross-linking method, using bovine serum albumin (BSA) in the presence of saturated glutaraldehyde vapor (GA). The preparation of the enzymatic membrane involves the incorporation of porcine pancreatic lipase (PPL), bovine serum albumin (BSA) and glycerol into a phosphate buffer solution (PBS). Characterization of this sensor was performed by impedance spectroscopy (EIS) and scanning electron microscope (SEM). The effect of experimental conditions such as PPL activity, potential, scan rate, PP concentration, pH and presence of interfering elements were studied by cyclic voltammetry. Findings Under the optimal experimental conditions, a number of significant factors were optimized. The method exhibited good linearity in the range of 10–14 to 10–9 mol/L with a good correlation coefficient of 0.957, detection limit (LOD) of 3.66 × 10–15 mol/L and high sensitivity of 1.086 mA mol−1L. The authors also obtained a very good coverage rate of the surface equal to 91.44%, and hydrolytic activity of lipase is evaluated to 26.64 mmol min−1. The stability and the interference were also evaluated. The equivalent circuit used to explain the electrochemical behavior of modified electrode is a Randle circuit. Practical implications The main application of biosensors is the detection of biomolecules that are either indicators of a disease. For example, electrochemical biosensing techniques can be used as clinical tools to detect breast tumors, because these compounds (PP) were found in breast tumors. Originality/value The result registered in this paper indicates that the developed sensor is an efficient, fast, simple and inexpensive analytical tool that can be used for the analysis of water containing PP.

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