scholarly journals The Influence of Talc Addition on the Performance of Polypropylene Membranes Formed by TIPS Method

Membranes ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 63 ◽  
Author(s):  
Marek Gryta
Keyword(s):  
Linear Structure ◽  
Membrane Distillation ◽  
Polymer Chains ◽  
Thermally Induced Phase Separation ◽  
Linear Arrangement ◽  
Thermally Induced ◽  
Capillary Membranes ◽  
The Stability ◽  
Long Term Studies

The effect of talc addition on the morphology of capillary membranes formed by a thermally induced phase separation (TIPS) method was investigated in the presented work. The usability of such formed membranes for membrane distillation was evaluated. Two types of commercial capillary polypropylene membranes, fabricated for microfiltration process, were applied in the studies. A linear arrangement of polymer chains was obtained in the walls of membranes formed without a talc addition. In the case of membranes blended with talc, the linear structure was disordered, and a more porous structure was obtained. The changes in morphology enhanced the mechanical properties of blended membranes, and their lower thermal degradation was observed during 350 h of membrane distillation studies. Long-term studies confirmed the stability of talc dispersion in the membrane matrix. A leaching of talc from polypropylene (PP) membranes was not found during the membrane distillation (MD) process.

Effect of Membrane Material Properties on Efficiency of Membrane Distillation

2011 ◽  
Vol 695 ◽  
pp. 85-88 ◽  
Author(s):  
Hwan Kim ◽  
June Seok Choi ◽  
Sang Ho Lee
Keyword(s):  
Membrane Distillation ◽  
Contaminated Water ◽  
Initial Screening ◽  
Membrane Material ◽  
Membrane Materials ◽  
Flat Sheet ◽  
Hydrophobic Membranes ◽  
The Stability ◽  
Physical And Chemical

Membrane distillation (MD) integrates membrane technology with evaporation process to produce fresh water from seawater or contaminated water. In this study, we investigated the effect of membrane materials on the efficiency of membrane distillation process. Flat sheet hydrophobic membranes (PVDF, PTFE) with different characterizes were chosen as well as hollow fiber membranes (PE). Laboratory-scale systems were developed for initial screening of various membranes. The performance of the membrane was analyzed in terms of water permeability and salt rejection. Synthetic seawater (TDS = 35,000 mg/L) was used for the lab-scale tests. A simple model to analyze the transport of water through MD membranes was developed to interpret experimental results. In addition, long-term performances of the membranes were compared to examine the stability of membrane materials and fouling tendency using real seawater. Based on the lab-scale experiments, techniques to improve the performance of the membranes were examined by applying physical and chemical modification.

Preparation of Hydrophobic Microporous Polypropylene/Isotactic Polypropylene Blending Membranes via Thermally Induced Phase Separation for Vacuum Membrane Distillation

2013 ◽  
Vol 790 ◽  
pp. 81-84 ◽  
Author(s):  
Na Tang ◽  
Shuang Zhang ◽  
Lei Zhang ◽  
Peng Gao Cheng ◽  
Jin Jin Li
Keyword(s):  
Phase Separation ◽  
Isotactic Polypropylene ◽  
Membrane Distillation ◽  
Mass Ratio ◽  
Thermally Induced Phase Separation ◽  
Nacl Solution ◽  
Optimum Conditions ◽  
Thermally Induced ◽  
Vacuum Membrane Distillation ◽  
Feed Temperature

The hydrophobic microporous membranes were prepared from a blend system by thermally induced phase separation (TIPS) process. The polymer blend system was isotactic polypropylene (iPP)/ high-density polyethylene (HDPE) and the diluent was soybean oil. The effects of the mass ratio of iPP and HDPE and the initial concentration of blending on the membranes structure were both investigated. Additionally, the influence of the feed temperature and the feed rate on the VMD performance of iPP/HDPE blend membranes was also investigated. For 0.5M aqueous NaCl solution, the VMD flux and reject ratio of the membranes reached 8.7kg/(m2·h) and nearly 100% under the optimum conditions (mass ration of iPP/HDPE was 6:1, and intial blend concentration was 38%), respectively.

scholarly journals Resistance of Polypropylene Membrane to Oil Fouling during Membrane Distillation

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 552
Author(s):  
Marek Gryta
Keyword(s):  
Membrane Distillation ◽  
Water Desalination ◽  
Feed Water ◽  
Permeate Flux ◽  
Feed Composition ◽  
Oil Emulsion ◽  
Thermally Induced ◽  
Polypropylene Membrane ◽  
Capillary Membranes ◽  
The Impact

The influence of oil emulsion presence in the water on the course of water desalination by membrane distillation was studied. The feed water was contaminated by oil collected from the bilge water. The impact of feed composition on the wetting resistance of hydrophobic polypropylene membranes was evaluated during long-term studies. Two types of the capillary membranes fabricated by thermally induced phase separation method were tested. It has been found that these membranes were non-wetted during the separation of NaCl solutions over a period of 500 h of modules exploitation. The addition of oil (5–100 mg/L) to the feed caused a progressive decline of the permeate flux up to 30%; however, the applied hydrophobic membranes retained their non-wettability for the consecutive 2400 h of the process operation. It was indicated that several compounds containing the carbonyl group were formed on the membranes surface during the process. These hydrophilic compounds facilitated the water adsorption on the surface of polypropylene which restricted the oil deposition on the membranes used.

Persistent homeothermy in large domestic mammals maintained under standard farming conditions

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Giuseppe Piccione ◽  
Claudia Giannetto ◽  
Elisabetta Giudice ◽  
Roberto Refinetti
Keyword(s):  
Rectal Temperature ◽  
Quantitative Measure ◽  
Circadian Oscillation ◽  
Unrestricted Access ◽  
The Stability ◽  
Access To Food ◽  
The Relationship ◽  
Long Term Studies ◽  
Daily Oscillation

AbstractBackgroundMammals, particularly large domestic ones, are considered to be year-round homeotherms. Surprisingly, however, very few long-term studies of the stability of core temperature of large domestic mammals have been conducted.MethodsWe monitored the auricular temperature and rectal temperature of goats, sheep, cows, and donkeys monthly for 2 years and compared their annual variation with their daily and day-to-day variations.ResultsAlthough ambient temperature varied from 8 °C in the winter to 30 °C in the summer, auricular temperature varied less than 0.5 °C, and rectal temperature varied less than 0.3 °C. We found that the daily oscillation in body temperature was up to three times as large as the day-to-day and month-to-month variations and that month-to-month variation was negligibly larger than day-to-day variation.ConclusionOur results confirm persistent homeothermy in large domestic mammals with unrestricted access to food and water and provide a quantitative measure of the relationship between long-term homeothermy and the wider range of daily/circadian oscillation.

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