Studying and developing the thin film membranes for reverse osmosis application

2018 ◽  
Author(s):  
◽  
Mohammed Kadhom
Keyword(s):  
Thin Film ◽  
Reverse Osmosis ◽  
Membrane Structure ◽  
Membrane Filtration ◽  
Low Cost ◽  
Inorganic Materials ◽  
Curing Temperature ◽  
Preparation Methods ◽  
Tfc Membrane ◽  
The Impact

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Desalination by semi-permeable membranes is the most applicable method of water-salt separation, where reverse osmosis (RO) account for the major portion of the overall water production. The membrane is the most important part in the RO process, which controls the amount of produced water and rejected salt. This work aimed to study and develop the state of the art membrane for this operation, the thin film composite (TFC) membrane. In the beginning, we introduced 2,2,4-trimethylpentane (isooctane) as a TMC solvent and used it through all our projects. Isooctane was introduced because of its appropriate properties as the organic phase solvent and relatively low volatility. Porous MCM-41 silica NPs were filled inside the membrane by dispersing those in MPD aqueous solution or in TMC organic solution. The thin film nanocomposite (TFN) membranes made via loading the silica NPs in the MPD solution had a slightly better performance than the filling in the TMC solution. By optimizing conditions of membrane synthesis, we developed high performance TFC membranes with the best performance results comparable or better than what were reported in the literature. We studied the effect of MPD and TMC contact times, PSU support sheet preparation methods and thickness, and curing temperature. The study showed that at 25 s MPD contact time and short reaction time, around 5 s, the membrane performance was the best. PSU support layer, however, affected the TFC membrane filtration efficiency. Reports were limited on the impact of support sheet to the TFC performance for desalination; we therefore evaluated the effects of PSU sheets preparation methods and thickness. The effect of curing temperature was also examined, showing that if the membrane was dried at 110 [degrees]C, it gave better results than at 80 [degrees]C. Bentonite NPs were examined as fillers as well since the material has good thermal and mechanical properties and is abundant in nature, easily available from synthesis in the laboratory with low cost, and environmentally green. Loading this material into TFN membrane improved its properties and performance. The thickness of these particles (~1 nm) helped fitting them tightly inside the membrane structure. To understand how the impact occurred, we investigated the reaction solvents adsorption in the meso and microporous cavities inside the particles. Water uptake phenomenon in clays was comprehended as a part of water transfer process inside the membrane, its impact on the membrane structure was considered. Finally, we investigated the filling of metal-organic frameworks (MOFs) in the TFN membrane. MOFs are a class of materials that combine organic and inorganic materials in one structure with many unique properties. Among over 20000 types of MOFs, we selected UiO-66 and MIL-125 to investigate because of their hydrophilic nature, water and chemical stability, large surface area and pore size, and low cost when comparing with other MOFs. We found that filling MIL-125 in the membrane improved water flux more than the UiO-66 did, while in both cases the salt rejection was maintained or increased at some loadings when comparing with the pristine membrane.

scholarly journals Antifouling Property of Oppositely Charged Titania Nanosheet Assembled on Thin Film Composite Reverse Osmosis Membrane for Highly Concentrated Oily Saline Water Treatment

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 237
Author(s):  
Nor Akalili Ahmad ◽  
Pei Sean Goh ◽  
Abdul Karim Zulhairun ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Thin Film ◽  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Saline Water ◽  
High Concentration ◽  
Saline Wastewater ◽  
Film Composite ◽  
Thin Film Composite ◽  
Tfc Membrane ◽  
Ro Membrane

With the blooming of oil and gas industries, oily saline wastewater treatment becomes a viable option to resolve the oily water disposal issue and to provide a source of water for beneficial use. Reverse osmosis (RO) has been touted as a promising technology for oily saline wastewater treatment. However, one great challenge of RO membrane is fouling phenomena, which is caused by the presence of hydrocarbon contents in the oily saline wastewater. This study focuses on the fabrication of antifouling RO membrane for accomplishing simultaneous separation of salt and oil. Thin film nanocomposite (TFN) RO membrane was formed by the layer by layer (LbL) assembly of positively charged TNS (pTNS) and negatively charged TNS (nTNS) on the surface of thin film composite (TFC) membrane. The unique features, rendered by hydrophilic TNS bilayer assembled on TFC membrane in the formation of a hydration layer to enhance the fouling resistance by high concentration oily saline water while maintaining the salt rejection, were discussed in this study. The characterization findings revealed that the surface properties of membrane were improved in terms of surface hydrophilicity, surface roughness, and polyamide(PA) cross-linking. The TFC RO membrane coated with 2-bilayer of TNS achieved >99% and >98% for oil and salt rejection, respectively. During the long-term study, the 2TNS-PA TFN membrane outperformed the pristine TFC membrane by exhibiting high permeability and much lower fouling propensity for low to high concentration of oily saline water concentration (1000 ppm, 5000 ppm and 10,000 ppm) over a 960 min operation. Meanwhile, the average permeability of uncoated TFC membrane could only be recovered by 95.7%, 89.1% and 82.9% for 1000 ppm, 5000 ppm and 10,000 ppm of the oily saline feedwater, respectively. The 2TNS-PA TFN membrane achieved almost 100% flux recovery for three cycles by hydraulic washing.

scholarly journals The influence of selenium amount added into the graphite box during the selenization of solution deposited CIGSe thin films.

2021 ◽  
Vol 2053 (1) ◽  
pp. 012008
Author(s):  
G M Albalawneh ◽  
M M Ramli ◽  
M ZM Zain ◽  
Z Sauli
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cell ◽  
High Performance ◽  
Low Cost ◽  
Precursor Solution ◽  
Precursor Film ◽  
Fine Grained ◽  
Thin Film Fabrication ◽  
The Impact

Abstract Cu(In,Ga)Se2 (CIGSe) semiconductor is an efficient light absorber material for thin-film solar cell technology. The sequential evaporation of precursor solution, followed by the selenization process, is a promising non-vacuum and low-cost approach for CIGSe thin-film fabrication. The main properties of CIGSe thin films are strongly affected by the post-selenization step. Hence, thorough control of selenization parameters is essential for achieving pure crystalline, large grain films needed for high-performance solar cell devices. In this study, the impact of selenium (Se) amount added during the selenization step was evaluated. The structural, morphological, and compositional properties of the selenized thin films were investigated. The CIGSe precursor film was deposited by a spin-coating technique using a thiol/amine-based solution, followed by annealing with different Se amounts (100, 200, and 300 mg) within a partially closed small round graphite container. In all cases, uniform films of 1.2–1.5 µm thickness with a well-defined single chalcopyrite phase were obtained. It was observed that the grain size and Se content increased with increasing Se mass added. Moreover, the sample selenized with 200 mg Se resulted in higher surface coverage, thinner fine-grained layer, and less MoSe2 formation than the excess Se samples.

Barrier and Seed Layers Deposition in TSV Using Magnetron Sputtering

2014 ◽  
Vol 543-547 ◽  
pp. 3951-3954
Author(s):  
Rui Dong Wang ◽  
Cong Chun Zhang ◽  
Gui Fu Ding ◽  
Yang Gao
Keyword(s):  
Thin Film ◽  
Aspect Ratio ◽  
Magnetron Sputtering ◽  
Seed Layer ◽  
Low Cost ◽  
Barrier Layers ◽  
Continuous Coverage ◽  
The Impact ◽  
3D Package ◽  
Seed Layers

This paper demonstrates the deposition of barrier layers and seed layers in TSV for 3D package. The high aspect ratio through silicon via sputtering process uses the magnetron-sputtering of Au. In order to achieve the continuous coverage of thin film on the sidewall and bottom of vertical microvias, the sputtering and anti-sputtering process was optimized. The impact of thickness of the seed layer and the gas pressure of the chamber on the coverage of the seed layers are discussed. The continuous seed layers and barrier layers on in the micro-vias with aspect ratio 3.5 can be achieved at low cost.

scholarly journals Feasibility and strength properties of the geopolymeric binder made of fly ash suspension

2019 ◽  
Vol 262 ◽  
pp. 06001
Author(s):  
Szymon Dawczyúski ◽  
Marek Soczyúski ◽  
Marcin GÓrski
Keyword(s):  
Fly Ash ◽  
Waste Product ◽  
Strength Properties ◽  
Inorganic Materials ◽  
Curing Temperature ◽  
Laboratory Research ◽  
Heat Curing ◽  
Energy Consuming ◽  
Main Components ◽  
The Impact

Geopolymeric binders, or in general geopolymers, are nowadays applied in many different branches of the industry –also in building construction. This relatively new group of inorganic materials has similar strength properties as ordinary Portland cement (OPC) and in some features, it is even better (for example in terms of fire resistance or chemical resistance). It is also environmentally friendly material because industrial or mining tailings are used as its main components and the production process is not so energy consuming as in case of OPC. Paper presents laboratory research focusing on the curing temperature impact on strength properties of geopolymeric binder made of fly ash suspension. Besides the suspension which is a waste product from coal power plant, also recycled ground glass and metakaolin were used as the additions. The chemical activator of geopolimerisation reaction was prepared with the use of sodium hydroxide and sodium silicate. Prism samples 40x40x160 mm were done and then the flexural and compressive strength tests were performed. The paper also presents the impact of covering the moulds during heat curing on condition of geopolymeric binder samples.

scholarly journals Important Approaches to Enhance Reverse Osmosis (RO) Thin Film Composite (TFC) Membranes Performance

Membranes ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 68 ◽  
Author(s):  
Ahmed Al Mayyahi
Keyword(s):  
Thin Film ◽  
Reverse Osmosis ◽  
Membrane Surface ◽  
Membrane Properties ◽  
Major Type ◽  
Future Research ◽  
Human Consumption ◽  
Film Composite ◽  
Thin Film Composite ◽  
Tfc Membrane

Thin film composite (TFC) membrane, which consists of polyamide (PA) active film rests on porous support layer, has been the major type of reverse osmosis (RO) membrane since its development by Cadotte in the 1970s, and has been remarkably used to produce clean water for human consumption and domestic utilization. In the past 30 years, different approaches have been exploited to produce the TFC membrane with high water flux, excellent salt rejection, and better chlorine/fouling resistance. In this brief review, we classify the techniques that have been utilized to improve the RO-TFC membrane properties into four categories: (1) Using alternative monomers to prepare the active layer; (2) modification of membrane surface; (3) optimization of polymerization reactions; and (4) incorporation of nanoparticles (NPs) into the membrane PA layer. This review can provide insights to guide future research and further propel the RO TFN membrane.

Impacts of secondary mixed monomer on properties of thin film composite (TFC) nanofiltration and reverse osmosis membranes: A review

2020 ◽  
Vol 14 ◽  
Author(s):  
John Ogbe Origomisan ◽  
Woei Jye Lau ◽  
Farhana Aziz ◽  
Ahmad F Ismail
Keyword(s):  
Thin Film ◽  
Reverse Osmosis ◽  
Membrane Filtration ◽  
Interfacial Polymerization ◽  
Acyl Chloride ◽  
Organic Solution ◽  
Film Composite ◽  
Thin Film Composite ◽  
Filtration Performance ◽  
The Subject

: Polyamide (PA) thin film composite (TFC) membranes are widely used for large-scale water and wastewater treatment processes worldwide owing to their good balance between water permeability and dissolved solutes separation rate. The physicochemical properties of the cross-linked PA layer are the main criteria determining the filtration performance of the resultant TFC membrane and this selective layer can be created through interfacial polymerization (IP) between two immiscible active monomers, i.e., amine monomer in aqueous solution and acyl chloride monomer in organic solution. This review article intends to provide insights to researchers in fabricating improved properties of TFC membranes through utilization of secondary monomers during IP process. To the best of our knowledge, this is the first review that gives a state-of-the-art account of the subject matter by emphasizing the impacts of secondary monomers (both amine and acyl chloride monomers) on the properties of conventional TFC membranes for nanofiltration and reverse osmosis applications. Our review indicated that the introduction of secondary monomers into either aqueous or organic solution could alter the physical and chemical properties of PA layer which led to variations in membrane filtration performance. Nevertheless, more research is still required as most of the secondary monomers reported in the literature did not overcome the membrane trade-off effect between permeability and selectivity. The subject of improved PA layer development is a multi-disciplinary study that requires researchers with different backgrounds (e.g., materials science, chemistry, physics and engineering) to work together.

scholarly journals Low-Cost High Performance Polyamide Thin Film Composite (Cellulose Triacetate/Graphene Oxide) Membranes for Forward Osmosis Desalination from Palm Fronds

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 6
Author(s):  
Tarek S. Jamil ◽  
Rabab A. Nasr ◽  
Hussien A. Abbas ◽  
Tamer I. M. Ragab ◽  
Sinethemba Xabela ◽  
...  
Keyword(s):  
Thin Film ◽  
High Performance ◽  
Low Cost ◽  
Forward Osmosis ◽  
Cellulose Triacetate ◽  
Salt Flux ◽  
Film Composite ◽  
Thin Film Composite ◽  
Tfc Membrane ◽  
Palm Fronds

Novel low-cost cellulose triacetate-based membranes extracted from palm fronds have been fabricated through the phase–inversion procedure. The cellulose tri-acetate (CTA) membrane was modified by incorporation of graphene oxide (GO) prepared from palm fronds according to the modified Hummer method as well as the preparation of polyamide thin film composite CTA membranes to improve forward osmosis performance for seawater desalination. The surface characteristics and morphology of the prepared CTA, GO, and the fabricated membranes were investigated. The modified TFC prepared membrane had superior mechanical characteristics as well as permeation of water. The performance of the prepared membranes was tested using synthetic 2 M Sodium chloride (NaCl) feed solution. The water flux (Jw) of the thin-film composite (TFC) (CTA/0.3% GO) was 35 L/m2h, which is much higher than those of pure CTA and CTA/0.3% GO. Meanwhile, the salt reverse flux TFC (CTA/0.3% GO) was 1.1 g/m2h), which is much lower than those of pure CTA and CTA/0.3%. GO (Specific salt flux of TFC (CTA/0.3% GO) substrate membrane was 0.03 g/L indicating good water permeation and low reverse salt flux of the TFC membrane compared to CTA. A real saline water sample collected from Hurgada, Egypt, with totally dissolved solids of 42,643 mg/L with NaCl as the draw solution (DS) at 25 °C and flow rate 1.55 L/min, was used to demonstrate the high performance of the prepared TFC membrane. The chemical analysis of desalted permeated water sample revealed the high performance of the prepared TFC membrane. Consequently, the prepared low-cost forward osmosis (FO) thin-film composite CTA membranes can be introduced in the desalination industry to overcome the high cost of reverse osmosis membrane usage in water desalination.

Cellulose Acetate Reverse Osmosis Membrane Structure

1972 ◽  
Vol 30 ◽  
pp. 528-529
Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin
Keyword(s):  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Membrane Structure ◽  
Freeze Drying ◽  
Dense Layer ◽  
Water Removal ◽  
Reverse Osmosis Membrane ◽  
Correct Interpretation ◽  
Electron Image ◽  
Scanning Electron

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.

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