Preparation of PVA Nanofiltration Membrane with Good Solvent Resistance

2014 ◽  
Vol 904 ◽  
pp. 71-73
Author(s):  
Jian Dong Zhang ◽  
Li Wang
Keyword(s):  
Reaction Time ◽  
Composite Membrane ◽  
Cross Linking ◽  
Nanofiltration Membrane ◽  
Solvent Resistance ◽  
Optimized Conditions ◽  
Preparation Parameter

Polyvinylalcohol (PVA) with good solvent resistance was used in preparation of nanofiltration membrane. The preparation parameter such as PVA concentration, cross-linking agent concentration and reaction time are studied in detail. When the composite membrane was prepared under optimized conditions and tested at 0.4 MPa and 20 °C, the flux of the NF membrane was about 15 L/m2h and the Na2SO4 rejection of it was about 53.3%.

Preparation of Carboxymethyl Cellulose Sodium/PEI Nanofiltration Membrane

2013 ◽  
Vol 800 ◽  
pp. 580-583 ◽  
Author(s):  
Run Lin Han ◽  
Yong Qing Wang ◽  
Xiao Zhen Zhang ◽  
Jian Er Zhou
Keyword(s):  
Composite Membrane ◽  
Carboxymethyl Cellulose ◽  
Curing Temperature ◽  
Nanofiltration Membrane ◽  
Functional Layer ◽  
Carboxymethyl Cellulose Sodium ◽  
Charged Membrane ◽  
High Valent ◽  
Optimized Conditions ◽  
Preparation Parameter

Carboxymethyl cellulose (CMC) sodium with negatively charged character was used as functional layer of polyetherimide (PEI) ultrafiltration membrane. The preparation parameter such as CMC concentration, cross-linking agent concentration and curing temperature are studied in detail. When the composite membrane was prepared under optimized conditions and tested at 0.4 MPa and 20 °C, the flux of the composite NF membrane was about 3 L/m2h and the MgCl2 rejection of it was about 87%. The composite membrane showed classical negatively charged membrane character which had higher rejection to high valent anion.

Preparation of High Oil-Absorbing Materials by Using Modified Microcrystalline Cellulose

2011 ◽  
Vol 308-310 ◽  
pp. 780-784
Author(s):  
Feng Zhi Tan ◽  
Ya Feng Cao ◽  
Da Zhi Wang
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Microcrystalline Cellulose ◽  
Base Material ◽  
Cross Linking ◽  
Mass Ratio ◽  
Absorbing Materials ◽  
Optimized Conditions

Abstract. In this paper, high oil-absorbing resin is prepared, using microcrystalline cellulose as base material, and acrylate as grafting monomer. Effect of mass ratio of microcrystalline cellulose/monomer, the amount of cross-linking agent, initiator dosage, reaction temperature, and reaction time on oil-absorbing properties of the products is investigated. The optimized conditions are as followed: reaction time 6 hours, reaction temperature 70 °C, mass ratio of microcrystalline cellulose to monomer 1:1.5. The oil absorbing ratio of the product prepared under these conditions is up to 12.9 g/g for toluene, and 14.6 g/g for kerosene oil.

A Cross-Linking Modification toward a High-Performance Polyimide Nanofiltration Membrane for Efficient Desalination

2021 ◽  
Author(s):  
Wenzhong Ma ◽  
Xinlei Dai ◽  
Pei Qiu ◽  
Hanwen Ye ◽  
Jing Zhong ◽  
...  
Keyword(s):  
High Performance ◽  
Cross Linking ◽  
Nanofiltration Membrane

scholarly journals Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation

2017 ◽  
Vol 76 (12) ◽  
pp. 3278-3288 ◽  
Author(s):  
Zhenchao Zhang
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Treatment Process ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Oily Wastewater ◽  
Optimum Conditions ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Optimized Conditions

Abstract In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H2O2 dosage of 12 mg/L, with a H2O2/Fe2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China (GB8978-1996).

scholarly journals Semi-Synthetic Approach Leading to 8-Prenylnaringenin and 6-Prenylnaringenin: Optimization of the Microwave-Assisted Demethylation of Xanthohumol Using Design of Experiments

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 4007
Author(s):  
Corinna Urmann ◽  
Herbert Riepl
Keyword(s):  
Reaction Time ◽  
Lithium Chloride ◽  
Biological Effects ◽  
Synthetic Approach ◽  
Prenylated Flavonoids ◽  
Microwave Assisted ◽  
Synthesis Strategy ◽  
Final Yield ◽  
Optimized Conditions ◽  
First Time

The isomers 8-prenylnaringenin and 6-prenylnaringenin, both secondary metabolites occurring in hops, show interesting biological effects, like estrogen-like, cytotoxic, or neuro regenerative activities. Accordingly, abundant sources for this special flavonoids are needed. Extraction is not recommended due to the very low amounts present in plants and different synthesis approaches are characterized by modest yields, multiple steps, the use of expensive chemicals, or an elaborate synthesis. An easy synthesis strategy is the demethylation of xanthohumol, which is available due to hop extraction industry, using lithium chloride and dimethylformamide, but byproducts and low yield did not make this feasible until now. In this study, the demethylation of xanthohumol to 8-prenylnaringenin and 6-prenylnaringenin is described the first time and this reaction was optimized using Design of Experiment and microwave irradiation. With the optimized conditions—temperature 198 °C, 55 eq. lithium chloride, and a reaction time of 9 min, a final yield of 76% of both prenylated flavonoids is reached.

Preparation and Application of Electrospinning Membranes of Thermoplastic Carboxymethyl Cellulose/PLA for Removal of Cu2+ from Aqueous Solutions

2012 ◽  
Vol 724 ◽  
pp. 61-64
Author(s):  
Ying Li ◽  
Xiao Yan Lin ◽  
Zhe Chen ◽  
Xue Guang Luo ◽  
Wei Li Zuo
Keyword(s):  
Tensile Strength ◽  
Aqueous Solutions ◽  
Removal Efficiency ◽  
Composite Membrane ◽  
Carboxymethyl Cellulose ◽  
Contact Time ◽  
Electrospinning Process ◽  
Cross Linking ◽  
Initial Concentration ◽  
The Cross

A composite membrane of thermoplastic carboxymethyl cellulose (TCMC) /PLA was prepared by electrospinning process, and crossliked by epichlorohydrin solution at different temperature. The cross-linking temperature was optimized by characterizing the morphology and tensile strength of the film. The optimal cross-linking temperature was 50°C. A composite membrane was used to remove Cu2+ from aqueous solutions, and the effects of initial concentration of Cu2+ and contact time on the removal efficiency of Cu2+ were investigated. The removal efficiency of Cu2+ was 13.78%, at the initial concentration of 40 mg·L-1 and contact time of 30s.

Optimizing the central steric hindrance of cross-linkable hole transport materials for achieving highly efficient RGB QLEDs

2020 ◽  
Vol 4 (11) ◽  
pp. 3368-3377
Author(s):  
Wenchao Zhao ◽  
Liming Xie ◽  
Yuan-Qiu-Qiang Yi ◽  
Xiaolian Chen ◽  
Jianfeng Hu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Steric Hindrance ◽  
Optoelectronic Devices ◽  
Hole Transport ◽  
Cross Linking ◽  
Solvent Resistance ◽  
Highly Efficient

Cross-linking strategies of hole transport materials (HTMs) have been widely investigated and used in various optoelectronic devices, mainly owing to their excellent solvent resistance and thermal stability.

Synthesis of Epoxidized Soybean Oil via Phase Transfer Catalysis

2013 ◽  
Vol 690-693 ◽  
pp. 1061-1064 ◽  
Author(s):  
Lu Jing ◽  
Guo Qin Liu ◽  
Xin Qi Liu ◽  
Xue De Wang
Keyword(s):  
Reaction Time ◽  
Soybean Oil ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Active Agent ◽  
Epoxidized Soybean Oil ◽  
Reaction Conditions ◽  
Epoxidation Reaction ◽  
Optimized Conditions ◽  
Epoxy Value

In the system of heteropoly acid [π-C5H5NC16H33]3[PO4(WO3)4], H2O2 (30 %, w/w), polyethylene glycol, 1,2-dichloroethane, soybean oil under went epoxidation reaction smoothly via reaction-controlled phase transfer catalysis. Effects of the amount of interfacial active agent, H2O2, catalyst and reaction time were investigated and the optimized reaction conditions were as follows: 10 g of soybean oil, 0.3 g of [π-C5H5NC16H33]3[PO4 (WO3)4],8 ml of H2O2 (30 %, w/w), 5.0 ml of PEG, 30 g of 1,2-dichloroethane, and the reaction temperature was 65 °C and reaction time was 3.5-4.0 h. Under these optimized conditions, an epoxy value of 6.30 % and a yield of 90 % were obtained. Hence, it is an environmental-friendly and effective way to synthesize epoxidized soybean oil.

Sign in / Sign up

Export Citation Format

Share Document