WO2011099941A1 - Forward osmosis process using hydrophilic magnetic nanoparticles as draw solutes - Google Patents
Forward osmosis process using hydrophilic magnetic nanoparticles as draw solutes Download PDFInfo
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- 9 1 9 1 magnetic core It has a water flux value of 8-40 Lm “ hr “ (e.g., 10 or 20 Lm “ hr " ) that decreases 10% or lower (e.g., 3% or 5%) after use as draw solutes.
- C is the molar concentration of the hydrophilic polymers on the magnetic core in water (mol/L)
- p density of the hydrophilic magnetic nanoparticles solution (g/L)
- w is the weight fraction of the hydrophilic polymers on the magnetic core
- M w is the molecular weight of the hydrophilic polymers (g/mol), assuming no change of solution volume (V) before and after adding the hydrophilic magnetic nanoparticles.
- the PAA-MNPs were recovered under an external magnetic field provided by High Gradient Magnetic Separator (HGMS, model L-1CN, Frantz canister separator, from S. G. Frantz Co., Inc. Trenton, NJ). After the PAA-MNPs were captured by HGMS, water was collected in downstream. The recovered PAA-MNPs were then reused as draw solutes in next run of a forward osmosis test. The results showed that, in certain runs, the water flux values of the recovered PAA-MNPs decreased as little as 10% compared to the value measured in the previous run of forward osmosis test.
- HGMS High Gradient Magnetic Separator
- FTIR spectra of the PEG-(COOH) 2 -MNPs were obtained from Perkin-Elmer FT- IR Spectrometer Spectrum 2000. The scan range was from 4000 to 400 cm -1 . Test samples of the PEG-(COOH) 2 -MNPs (pressed into KBr pellets) were dried overnight under vacuum at 80 °C before any measurement. FTIR spectra indicated that PEG- (COOH) 2 were covalently bound to iron oxide core (Fe 3 C>4).
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Abstract
Disclosed is a hydrophilic magnetic nanoparticle including a magnetic core and a plurality of hydrophilic polymers covalently bound to the magnetic core. The hydrophilic magnetic nanoparticle has a water flux value of 8-40 L.m-2.hr-1 that decreases 10 % or less after use as a draw solute. Also disclosed is a method of preparing the hydrophilic magnetic nanoparticles.
Description
FORWARD OSMOSIS PROCESS USING HYDROPHILIC MAGNETIC NANOPARTICLES AS DRAW SOLUTES
BACKGROUND OF THE INVENTION
Forward osmosis is an osmotic process that uses a semi-permeable membrane to separate water from dissolved solutes. More specifically, water crosses a semi-permeable membrane from a higher water potential side (a "feed solution") to a lower water potential side (a "draw solution") without the aid of hydraulic pressure, the driving force being the osmotic pressure differential between the two solutions.
In forward osmosis, solutes in the draw solution ("draw solutes") are used to induce high osmotic pressure, causing a net flow of water through the membrane into the draw solution. See T. Cath, et al., J. Membrane Sci., 2006, 281, 70-87. Ideally, the draw solutes are easily separated and recycled from water. See J.R. McCutcheon,
Desalination, 2005, 174, 1 - 11.
Many chemicals have been used as draw solutes, e.g., sodium chloride, sulfur dioxide, aluminum sulfate, and potassium nitrate. See G.W. Batcher,
US Patent 3,216,930, B.S. Frank, US Patent 3,670,897, R. McGinnis, US Patent
6,391,205. While these chemicals are inexpensive, costly procedures (e.g., distillation) are typically required to separate them from water.
There is a need for new draw solutes in forward osmosis that are effective, inexpensive, and facile to separate from water.
SUMMARY OF THE INVENTION
One aspect of this invention relates to a hydrophilic magnetic nanoparticle that can be used as a draw solute in forward osmosis. The hydrophilic magnetic nanoparticle includes a magnetic core and a plurality of hydrophilic polymers covalently bound to the
9 1 9 1 magnetic core. It has a water flux value of 8-40 Lm" hr" (e.g., 10 or 20 Lm" hr" ) that decreases 10% or lower (e.g., 3% or 5%) after use as draw solutes.
The magnetic core has a diameter of 1-200 nm (e.g., 2-60 nm). It is composed of MFe204 (e.g., Fe304), Fe203, or a mixture thereof, in which M is Fe, Co, or Mn.
Each of the hydrophilic polymers includes 1-70 (e.g., 2-30) carboxylic groups. Examples include poly(ethylene glycol) diacid, polyacrylic acid, poly(styrene)-block- poly(acrylic acid), poly(acrylic acid-co-maleic acid), poly(acrylamide-co-acrylic acid), and poly(vinyl acetate-co-crotonic acid). When poly(ethylene glycol) diacid and polyacrylic acid are used, it is preferred that they have average molecular weights of 100- 20000 (e.g., 200-6000) and 70-5000 (e.g., 100-2100), respectively.
Another aspect of this invention relates to an inexpensive one-pot method of preparing hydrophilic magnetic nanoparticles. The method includes at least four steps: (1) passing an inert gas to a hydrophilic solvent containing an oxygen-containing iron salt and a hydrophilic polymer, the solvent having a boiling point of 150 °C or higher, (2) heating the solvent to a temperature of 150 °C - 500 °C to obtain hydrophilic magnetic nanoparticles, each containing (i) a magnetic core that has a diameter of 1-200 nm and is composed of MFe204, Fe203, or a mixture thereof, in which M is Fe, Co, or Mn, and (ii) a plurality of hydrophilic polymers covalently bound to the magnetic core, (3) cooling the solvent to a temperature lower than 150 °C, and (4) collecting the hydrophilic magnetic nanoparticles from the solvent.
Examples of the hydrophilic solvent include triethylene glycol, carbitol, polyethylene glycol, methoxy polyethylene glycol, dimethylformamide, propylene carbonate, and glycerol.
Examples of the oxygen-containing iron salt include tris(acetylacetonato) iron
(III), iron pentacarbonyl, and iron cupferron.
Examples of the hydrophilic polymers include polypyrrolidone, poly(ethylene glycol), poly(ethylene oxide), polyvinylpyrrolidone, polysaccharide, polyurethane, and those listed above.
The hydrophilic magnetic nanoparticles prepared by the above-described method are also within the scope of this invention.
The details of one or more examples of the invention are set forth in the description below. Other features, objects, and advantages of the invention will be apparent from the detailed description of the examples and also from the appending claims.
DETAILED DESCRIPTION OF THE INVENTION
As magnetic nanoparticles can be collected and separated from water under an external magnetic field, they are candidates for draw solutes in forward osmosis. Yet, many reports describe magnetic nanoparticles that have low solubility in water and are thus not suitable for use as draw solutes. See, e.g., Y. Wang, et al., Nano Letters, 2003, 3, 1555-1559; and J.D. Hearn, et al., Phys. Chem. Chem. Phys., 2005, 7, 501- 511.
Magnetic nanoparticles of this invention that contain carboxylic groups exhibit greatly improved water solubility and are suitable for use as draw solutes.
Also within the scope of this invention is a one-pot thermal decomposition method for preparing hydrophilic magnetic nanoparticles. It includes the following steps:
An oxygen-containing iron salt and a hydrophilic polymer are added to a hydrophilic solvent (e.g., triethylene glycol or glycerol) that has a boiling point of 150 °C or higher with an inert gas (e.g., nitrogen or argon) passed through the solvent to remove oxygen. An oxygen-containing cobalt salt (e.g., tris(acetylacetonato) cobalt) or an oxygen-containing manganese salt (e.g., tris(acetylacetonato) manganese, manganese cupferron) can also be added to the solvent in order to obtain a magnetic core composed of MFe04, M being Co or Mn.
The solvent is heated to a temperature of 150 °C - 500 °C for a predetermined period of time (e.g., less than one hour) to obtain hydrophilic magnetic nanoparticles. Upon cooling of the solvent to a temperature lower than 150 °C, the hydrophilic magnetic nanoparticles are collected from the solvent.
Of note, the diameter of the hydrophilic magnetic nanoparticles can be tuned by adding different amounts of hydrophilic polymers as shown in examples below.
The carboxylic groups-containing hydrophilic magnetic nanoparticles obtained from the above-described method are routinely tested as draw solutes in forward osmosis process. The capacity of these magnetic nanoparticles (used as draw solutes) is evaluated by the water flux, which measures a volume change of a feed solution using the following equation:
Jv = AVI (A: At)
where Jv (Lm 2 hr'1, abbreviated as LMH) represents water flux, AV (L) is the volume change of the feed solution over a predetermined time At (hr) and A is the effective membrane surface area (m2) based on the external diameter of hollow fibers.
The test can be conducted on a lab-scale setup following the procedure described in Wang et al., Journal of Membrane Science, 2007, 300, 6-12 (Wang et al.):
A draw solution of hydrophilic magnetic nanoparticles and a feed solution of deionized water are pumped countercurrently through a module by two peristaltic pumps (Easy-load® 7518-10, Cole Parmer, USA). Both draw solution and feed solution are circulated on each side of an HTI flat sheet membrane (Batch No. 060327-3, Hydration Technologies Inc., OR, USA). Two different membrane orientations are tested: (i) a pressure retarded osmosis mode when the draw solution flows against the selective layer, and (ii) a forward osmosis mode when the draw solution flows against the porous support layer. A balance connected to a computer records mass of water permeating into the draw solution over a selected period of time.
After the test, the hydrophilic magnetic nanoparticles are then collected under an external magnetic field. They can be reused as draw solutes in forward osmosis process.
As shown in the examples below, carboxylic groups-containing hydrophilic magnetic nanoparticles unexpectedly have both high water flux (i.e., 8-40 LMH) and high stability (i.e., a < 10% decrease of water flux after each use as draw solutes).
The water flux values 8-40 LMH recited immediately above are measured following the procedure described in Wang et al., under the following conditions: (i) the draw solution of the carboxylic groups-containing hydrophilic magnetic nanoparticles has a polymer concentration of 0.07 mol/L, (ii) the HTI flat sheet membrane (Batch No. 060327-3, Hydration Technologies Inc., OR, USA) is used, (iii) the test is run in a pressure retarded osmosis mode, and (iv) deionized water is used as the feed solution.
The stability of these nanoparticles, i.e., "a < 10% decrease" recited above, is measured based on the decrease of the water flux after they haven been reused as draw solutes in another run of a forward osmosis test. The decrease is attributable mainly to slight particle aggregation during recovery.
The concentration of the hydrophilic polymers covalently bound to each magnetic core is calculated using the formula below:
c _ {p - \) w V _ {p - \)- w
MK - V Mw
Where C is the molar concentration of the hydrophilic polymers on the magnetic core in water (mol/L), p is density of the hydrophilic magnetic nanoparticles solution (g/L), w is the weight fraction of the hydrophilic polymers on the magnetic core, Mw is the molecular weight of the hydrophilic polymers (g/mol), assuming no change of solution volume (V) before and after adding the hydrophilic magnetic nanoparticles.
When using carboxylic groups-containing hydrophilic magnetic nanoparticles of this invention in forward osmosis, polymer concentrations of 0.01-0.1 mol/L (e.g., 0.04— 0.08 mol/L) are typically prepared.
Hydrophilic magnetic nanoparticles prepared by the above-described one-pot thermal decomposition method unexpectedly exhibit both high water flux with suitable size distribution and high stability.
The application of hydrophilic magnetic nanoparticles as draw solutes in forward osmosis can be used in desalination, waster water reclamation, proteins and
pharmaceuticals concentration.
Without further elaboration, it is believed that one skilled in the art can, based on the disclosure herein, utilize the present invention to its fullest extent. The following specific examples are, therefore, to be construed as merely descriptive, and not limitative of the remainder of the disclosure in any way whatsoever. All publications cited herein are incorporated by reference.
Polyacrylic acid-Magnetic Nanoparticles (PAA-MNPs)
Unless otherwise stated, all chemicals were used as commercially supplied. All reactions were carried out under argon protection with the use of standard Schlenk techniques. Iron (III) acetylacetonate (Fe(acac)3, 99.9%), triethylene glycol (98%), and polyacrylic acid (PAA, w=1800, 98%) were purchased from Sigma- Aldrich. Ethanol (99%) and ethyl acetate (99%) were obtained from Acros Organics. Deionized water used in experiments was from the Milli-Q (Millipore, USA) system.
Synthesis and characterization of PAA-MNPs
Polyacrylic acid-Fe304 magnetic nanoparticles (PAA-MNPs) were synthesized by a thermal decomposition method. 1.0 g of polyacrylic acid was magnetically stirred in 25 mL of triethylene glycol under a flow of argon. After polyacrylic acid was completely dissolved in triethylene glycol, 2.0 mmol Fe(acac)3 was added. The resulting mixture was slowly heated to 190 °C for 30 min and then quickly heated at reflux under argon for 20 min. A black homogeneous colloidal suspension was obtained and cooled down to room temperature. Excess amounts of ethyl acetate were added to the mixture resulting in black precipitation, the precipitate was separated via centrifugation. The black products were re-dissolved in ethanol and re-precipitated in ethyl acetate for several times to remove residuals thoroughly. The obtained PAA-MNPs were dispersed in water for further characterization.
A drop of PAA-MNPs dispersion was placed on amorphous carbon-coated copper grids and imaged by using a field emission scanning electronic microscope (FESEM, JEOL JSM-6700). The images revealed that PAA-MNPs were mono-dispersed in water in an average diameter of 20-30 nm.
Fourier transform infrared (FTIR) spectra of PAA-MNPs (pressed into KBr pellets) were obtained from a Bio-Rad Spectrometer of FTS 135. The spectra
demonstrated that polyacrylic acids were covalently bound to iron oxide core (Fe304).
Magnetic behavior of PAA-MNPs was recorded in a vibrating sample
magnetometer (VSM, LakeShore 450-10) with a saturating field of 1.0 T at room temperature. No coericivity or remanence was observed by magnetic measurements. Forward osmosis tests of PAA-MNPs
Forward osmosis tests of PAA-MNPs were conducted on a lab-scale setup described in Wang et al., Journal of Membrane Science, 300, 2007, 6-12. HTI flat sheet membrane (Batch No. 060327-3, Hydration Technologies Inc., OR, USA) was used in the tests. Two different membrane orientations were tested: 1) the pressure retarded osmosis mode for when the draw solution flows against the selective layer, and 2) the forward osmosis mode for when the draw solution flows against the porous support layer.
When the polymer concentration of PAA-MNPs was 0.052 mol/L, the water flux values of PAA-MNPs in pressure retarded osmosis mode and in forward osmosis mode
were 10.4 and 7.7 LMH. In contrast, when the polymer concentration was 0.013 mol/L, the water flux values of PAA-MNPs were 6.1 and 4.0 LMH in the two different modes. The test results also indicated that water flux value was proportional to the polymer concentration of PAA-MNPs.
Recovery of PAA-MNPs by an external magnetic field
The PAA-MNPs were recovered under an external magnetic field provided by High Gradient Magnetic Separator (HGMS, model L-1CN, Frantz canister separator, from S. G. Frantz Co., Inc. Trenton, NJ). After the PAA-MNPs were captured by HGMS, water was collected in downstream. The recovered PAA-MNPs were then reused as draw solutes in next run of a forward osmosis test. The results showed that, in certain runs, the water flux values of the recovered PAA-MNPs decreased as little as 10% compared to the value measured in the previous run of forward osmosis test.
Water flux values comparison based on the sizes of PAA-MNPs
PAA-MNPs of 3.6 nm, 4.5 nm, 6.2 nm, and 18.2 nm average diameters were obtained by adding 5.0 g, 4.0 g, 3.0 g, and 2.0 g of polyacrylic acid in 50 ml triethylene glycol in reactions, respectively. The particle size distributions of PAA-MNPs were measured by Zetasizer (nano-ZS from Malvern). The results indicated that the PAA- MNPs produced by the thermal decomposition method had narrow size distributions.
Forward osmosis test results showed that PAA-MNPs of smaller diameters generated higher water flux.
Polyethylene glycol diacids- Ma netic Nanoparticles (PEG-(COOH -MNPs)
Unless otherwise stated, all chemicals were used as commercially supplied. All reactions were carried out under argon protection with use of standard Schlenk techniques. Triethylene glycol, 98%, Fe(acac)3, 99%, polyethylene glycol diacid 250 (PEG-(COOH)2 Mw = 250), 99%, and PEG-(COOH)2600 (Mw = 600), 99% were purchased from Aldrich. PEG-(COOH)24000 (Mw = 4000) was prepared using the method reported by Feng et al. Colloids Surf A: Physicochem. Eng. Aspects, 2008, 328, 52-59. Ethyl acetate (99%) was obtained from Acros Organics. Deionized water used in experiments was from the Milli-Q (Millipore, USA) system.
Synthesis and characterization of PEG-(COOH)?-MNPs
A. 11.7 nm [PEG-(COOH)2 250]-MNPs (1 :2)
11.7 nm [PEG-(COOH)2 250]-Fe3O4 magnetic nanoparticles ([PEG-(COOH)2 250]-MNPs (1 :2)) were synthesized by a thermal decomposition method. 30 mL of Methylene glycol and 1.0 mmol PEG-(COOH)2 (Mw = 250, 0.25 g) were mixed with
2.0 mmol Fe(acac)3 (0.71 g) in a three-necked flask. Under a flow of argon, the resulting mixture was heated to 280 °C and stirred at the same temperature for 30 min to obtain a black suspension. After the suspension was cooled to room temperature, 100 mL of ethyl acetate was added to the suspension to precipitate [PEG-(COOH)2 250]-MNPs (1:2). The precipitated magnetic nanoparticles were separated by centrifugation and washed three times with water/ethyl acetate (v/v 1 :3). Subsequently, [PEG-(COOH)2 250]-MNPs (1 :2) were dispersed in water and dialyzed for 2 days to remove species with less molecular weight. Finally, ethyl acetate was added to the dispersion after dialysis and [PEG- (COOH)2 250]-MNPs (1 :2) were re-precipitated. The obtained [PEG-(COOH)2 250]- MNPs (1 :2) had an average diameter of 11.7 nm (determined by a Nanoparticle Size
Analyzer, Nano ZS, ZEN3600 and transmission electron microscopy, JEOL, TEM-2010) and were ready for characterization and performance tests.
B. 13.5 nm [PEG-(COOH)2 600]-MNPs (1:2)
13.5 nm [PEG-(COOH)2 600]-Fe3O4 magnetic nanoparticles (1:2) were synthesized in the same procedure for 11.7 nm [PEG-(COOH)2 250]-MNPs (1 :2), except that [PEG-(COOH)2 600] was used instead of [PEG-(COOH)2 250] .
C. 17.5 nm [PEG-(COOH)2 4000]-MNPs (1:2)
17.5 nm [PEG-(COOH)2 4000]-Fe3O4 magnetic nanoparticles (1 :2) were synthesized in the same procedure for 11.7 nm [PEG-(COOH)2 250]-M Ps (1 :2), except that [PEG-(COOH)2 4000] was used instead of [PEG-(COOH)2 250] .
D. Characterization of PEG-(COOH)2- NPs
The PEG-(COOH)2-MNPs were fully characterized by transmission electron microscopy (TEM), VSM, FTIR, and themogravimetric analyzer (TGA).
The size distribution and morphology of the PEG-(COOH)2-MNPs were determined by Nanoparticle Size Analyzer (Nano ZS, ZEN3600) and TEM (JEOL TEM- 2010). Test results indicated that they were mono-dispersed in water and approximately
spherical. The results also indicated that the PEG-(COOH)2-MNPs produced by the thermal decomposition method had narrow size distributions.
The magnetic behavior of the PEG-(COOH)2-MNPs was measured through VSM (LakeShore 450-10) from -17 to 17 KOe at room temperature. The saturation
magnetization values were normalized to the mass of nanoparticles to yield the specific magnetization, M. No coericivity or remanence was observed by magnetic measurement. The test results demonstrated that the PEG-(COOH)2-MNPs exhibited superparamagnetic behavior at room temperature and possessed a certain level of magnetic response.
FTIR spectra of the PEG-(COOH)2-MNPs were obtained from Perkin-Elmer FT- IR Spectrometer Spectrum 2000. The scan range was from 4000 to 400 cm-1. Test samples of the PEG-(COOH)2-MNPs (pressed into KBr pellets) were dried overnight under vacuum at 80 °C before any measurement. FTIR spectra indicated that PEG- (COOH)2 were covalently bound to iron oxide core (Fe3C>4).
A TGA 2050 themogravimetric analyzer (TA Instruments, New Castle, DE) was used to characterize weight loss of hydrophilic magnetic nanoparticles during thermal decomposition. The measurement was carried out under nitrogen with a heating rate of 10 °C/min from 50 °C to 750 °C. A continuous weight loss was observed in a
temperature of 200 °C - 400 °C due to decomposition of PEG-(COOH)2. The amount of PEG-(COOH)2 bound to the surface of iron oxide (Fe304) was calculated from TGA measurement.
Forward osmosis tests ofPEG-(COOH)?-MNPs
Forward osmosis tests were conducted through a lab-scale circulating filtration unit as described in Wang et al., Journal of Membrane Science, 2007, 300, 6-12. HTI flat sheet membrane (Batch No. 060327-3, Hydration Technologies Inc., OR, USA) and home-made CA nanofiltration hollow fiber membranes were used in the tests. See J. Su, et al., Journal of Membrane Science, 2010, 355, 36-44. Two different membrane orientations were tested: 1) the pressure retarded osmosis mode when the draw solution flowed against the selective layer; and 2) the forward osmosis mode when the draw solution flows against the porous support layer.
A. Forward osmosis tests on HTI flat sheet membranes
Draw solutions prepared from the [PEG-(COOH)2250]-MNPs (1 :2), [PEG- (COOH)2 600]-MNPs (1 :2), and [PEG-(COOH)2 4000]-MNPs (1 :2) were evaluated in the forward osmosis tests using HTI flat sheet membranes. All the draw solutions had same polymer concentration of 0.065 mol/L. In a 30-min forward osmosis test in the pressure retarded osmosis mode, the water flux values were 13.5, 13.0, and 11.6 LMH for the draw solutions of [PEG-(COOH)2 250]-MNPs (1 :2), [PEG-(COOH)2 600]-MNPs (1 :2), and [PEG-(COOH)2 4000]-MNPs ( 1 :2), respectively.
The draw solutions of [PEG-(COOH)2 600]-MNPs (1 :2) with different concentrations (0.013, 0.026, 0.039, 0.052, and 0.065 mol/L) were tested in both pressure retarded osmosis and forward osmosis modes. The results showed that the [PEG- (COOH)2 600]-MNPs (1 :2) had better water flux values in the pressure retarded osmosis mode than in the forward osmosis mode due to internal concentration polarization. When the polymer concentration of [PEG-(COOH)2 600]-MNPs (1 :2) increased from 0.013 to 0.065 mol/L, the water flux values in pressure retarded osmosis and forward osmosis modes increased from 7.1 to 13.0 LMH and from 5.3 to 9.1 LMH, respectively. After each test, the conductivity of feed solution was measured and no draw solute leakage was found in the feed solution side.
B. Forward osmosis tests on CA nanofiltration hollow fiber membranes
The draw solutions of [PEG-(COOH)2 600]-MNPs (1 :2) were also tested using self-made nanofiltration hollow fiber membranes in the pressure retarded osmosis mode. When the polymer concentration of [PEG-(COOH)2 600]-MNPs (1 :2) increased from 0.013 to 0.065 mol/L, the water flux values increased from 5.4 to 11.1 LMH. Compared to the results in Experiment A, the water flux differences from the two different membranes were minimal.
Recovery ofiPEG- COOH)L600J-MNPs by an external magnetic field
The [PEG-(COOH)2600]-MNPs (1 :2) were recovered under an external magnetic field provided by High Gradient Magnetic Separator (HGMS, model L-1CN, Frantz canister separator, from S. G. Frantz Co., Inc. Trenton, NJ). After the [PEG-(COOH)2 600]-MNPs (1 :2) were captured by HGMS, water was collected in downstream. The recovered [PEG-(COOH)2600]-MNPs (1 :2) were then reused as draw solutes in next run
of a forward osmosis test. The test results exhibited that they were still active after 9 runs of recycles with a water flux decrease of 5% or less after each run of the test. At the end of 9 runs of recycles, the water flux value decreased 21% from the initial value of 13.0 to 10.3 LMH. This decrease was mainly caused by slight particle aggregation (from
13.5 ran to 19.0 nm) during the recovery.
OTHER EMBODIMENTS
All of the features disclosed in this specification may be combined in any combination. Each feature disclosed in this specification may be replaced by an alternative feature serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.
From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. Thus, other examples are also within the claims.
Claims
1. A hydrophilic magnetic nanoparticle comprising:
a magnetic core having a diameter of 1-200 nm, composed of MFe204, Fe203, or a mixture thereof, in which M is Fe, Co, or Mn, and
a plurality of hydrophilic polymers covalently bound to the magnetic core, each of the hydrophilic polymers containing 1-70 carboxylic groups,
wherein the hydrophilic magnetic nanoparticle has a water flux value of 8-40 L m^ hr"1 that decreases 10% or lower after use as a draw solute.
2. The hydrophilic magnetic nanoparticle of claim 1, wherein the magnetic core has a diameter of 2-60 nm and each of the hydrophilic polymers contains 2-30 carboxylic groups.
3. The hydrophilic magnetic nanoparticle of claim 1 , wherein the magnetic core is composed of Fe304.
4. The hydrophilic magnetic nanoparticle of claim 1 , wherein the hydrophilic polymers are poly(ethylene glycol) diacids, polyacrylic acids, poly(styrene)-block- poly(acrylic acid)s, poly(acrylic acid-co-maleic acid)s, poly(acrylamide-co-acrylic acid)s, poly(vinyl acetate-co-crotonic acid)s, or a combination thereof.
5. The hydrophilic magnetic nanoparticle of claim 4, wherein the hydrophilic polymers are polyacrylic acids.
6. The hydrophilic magnetic nanoparticle of claim 5, wherein the polyacrylic acids have an average molecular weight of 70-5000.
7. The hydrophilic magnetic nanoparticle of claim 4, wherein the hydrophilic polymers are poly(ethylene glycol) diacids.
8. The hydrophilic magnetic nanoparticle of claim 7, wherein the poly(ethylene glycol) diacids have an average molecular weight of 100-20000.
9. The hydrophilic magnetic nanoparticle of claim 2, wherein the magnetic core is composed of Fe304.
10. The hydrophilic magnetic nanoparticle of claim 9, wherein the polyacrylic acids have an average molecular weight of 100-2100.
11. The hydrophilic magnetic nanoparticle of claim 10, wherein the water flux value is 10-20 Lm" 2 hr" 1 that decreases 10% or lower after use as a draw solute.
12. The hydrophilic magnetic nanoparticle of claim 9, wherein the poly(ethylene glycol) diacids have an average molecular weight of 200-6000.
13. The hydrophilic magnetic nanoparticle of claim 12, wherein the water flux value is 10-20 L m" hr" that decreases 5% or lower after use as a draw solute.
14. Hydrophilic magnetic nanoparticles prepared by a process comprising:
passing an inert gas to a hydrophilic solvent containing an oxygen-containing iron salt and a hydrophilic polymer, the solvent having a boiling point of 150 °C or higher, heating the solvent to a temperature of 150 °C - 500 °C to obtain hydrophilic magnetic nanoparticles, each containing (i) a magnetic core that has a diameter of 1-200 nm and is composed of MFe204, Fe203, or a mixture thereof, in which M is Fe, Co, or Mn, and (ii) a plurality of hydrophilic polymers covalently bound to the magnetic core, cooling the solvent to a temperature lower than 150 °C, and
collecting the hydrophilic magnetic nanoparticles from the solvent.
15. The hydrophilic magnetic nanoparticles of claim 14, wherein the oxygen- containing iron salt is tris(acetylacetonato) iron (III), iron pentacarbonyl, iron cupferron, or a combination thereof.
16. The hydrophilic magnetic nanoparticles of claim 14, wherein the hydrophilic solvent is triethylene glycol, carbitol, polyethylene glycol, methoxy polyethylene glycol, dimethylformamide, propylene carbonate, glycerol, or a combination thereof.
17. The hydrophilic magnetic nanoparticles of claim 14, wherein the hydrophilic polymers are polypyrrolidones, poly(ethylene glycol)s, polyacrylic acids, poly(ethylene glycol) diacids, polyacrylates, poly(ethylene oxide)s, polyvinylpyrrolidones,
polysaccharides, polyurethanes, polyacrylates, poly(styrene)-block-poly(acrylic acid)s, poly(acrylic acid-co-maleic acid)s, poly(acrylamide-co-acrylic acid)s, poly( vinyl acetate- co-crotonic acid)s, or a combination thereof.
18. The hydrophilic magnetic nanoparticles of claim 17, wherein the hydrophilic polymers are polyacrylic acids having an average molecular weight of 70-5000.
19. The hydrophilic magnetic nanoparticles of claim 17, wherein the hydrophilic polymers are poly(ethylene glycol) diacids having an average molecular weight of 100- 20000.
20. The hydrophilic magnetic nanoparticles of claim 14, wherein the magnetic core is composed of Fe 04 having a diameter of 2-60 nm.
21. The hydrophilic magnetic nanoparticles of claim 20, wherein the hydrophilic polymers are polyacrylic acids having an average molecular weight of 70-5000.
22. The hydrophilic magnetic nanoparticles of claim 20, wherein the hydrophilic polymers are poly(ethylene glycol) diacids having an average molecular weight of 100- 20000.
23. A method of preparing hydrophilic magnetic nanoparticles comprising:
passing an inert gas to a hydrophilic solvent containing an oxygen-containing iron salt and a hydrophilic polymer, the solvent having a boiling point of 150 °C or higher, heating the solvent to a temperature of 150 °C - 500 °C to obtain hydrophilic magnetic nanoparticles, each containing (i) a magnetic core that has a diameter of 1-200 nm and is composed of MFe204, Fe203, or a mixture thereof, in which M is Fe, Co, or Mn, and (ii) a plurality of hydrophilic polymers covalently bound to the magnetic core, cooling the solvent to a temperature lower than 150 °C, and
collecting the hydrophilic magnetic nanoparticles from the solvent.
24. The method of claim 23, wherein the oxygen-containing iron salt is
tris(acetylacetonato) iron (III), iron pentacarbonyl, iron cupferron, or a combination thereof.
25. The method of claim 23, wherein the hydrophilic solvent is triethylene glycol, carbitol, polyethylene glycol, methoxy polyethylene glycol, dimethylformamide, propylene carbonate, glycerol, or a combination thereof.
26. The method of claim 23, wherein the hydrophilic polymers are polypyrrolidones, poly(ethylene glycol)s, polyacrylic acids, poly(ethylene glycol) diacids, polyacrylates, poly(ethylene oxide)s, polyvinylpyrrolidones, polysaccharides, polyurethanes, polyacrylates, poly(styrene)-block-poly(acrylic acid)s, poly(acrylic acid-co-maleic acid)s, poly(acrylamide-co-acrylic acid)s, poly( vinyl acetate-co-crotonic acid)s, or a
combination thereof.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140151295A1 (en) * | 2012-11-30 | 2014-06-05 | Korea Institute Of Science And Technology | Plants for advanced treatment of wastewater and method for treating wastewater using thereof |
| CN103864179A (en) * | 2014-03-14 | 2014-06-18 | 厦门大学 | Forward osmosis extracting solution as well as preparation method and application thereof |
| WO2015076755A1 (en) * | 2013-11-21 | 2015-05-28 | National University Of Singapore | One-pot mass production of nanoparticles |
| WO2015177391A1 (en) * | 2014-05-19 | 2015-11-26 | Consejo Superior De Investigaciones Científicas (Csic) | Nanostructured electrolyte useful for direct osmosis desalination, method for obtaining the electrolyte and uses of same |
| US9447239B2 (en) | 2012-03-19 | 2016-09-20 | Samsung Electronics Co., Ltd. | Thermosensitive copolymers, forward osmosis water treatment devices including the same, and methods of producing and using the same |
| WO2017051075A1 (en) | 2015-09-23 | 2017-03-30 | Kemira Oyj | Functionalized magnetic nanoparticles and a method for preparation thereof |
| US10319502B2 (en) | 2014-10-23 | 2019-06-11 | Corning Incorporated | Polymer-encapsulated magnetic nanoparticles |
| EP3819018A1 (en) * | 2019-11-08 | 2021-05-12 | Nanogap Sub NM Powder, S.A. | Forward osmosis draw solute |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010043914A2 (en) * | 2008-10-17 | 2010-04-22 | Apaclara Ltd | Water purification method |
-
2011
- 2011-02-10 WO PCT/SG2011/000062 patent/WO2011099941A1/en active Application Filing
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010043914A2 (en) * | 2008-10-17 | 2010-04-22 | Apaclara Ltd | Water purification method |
Non-Patent Citations (9)
| Title |
|---|
| FANG ET AL.: "Multifunctional magnetic nanoparticles for medical imaging applications", J. MATER. CHEM., vol. 19, 1 January 2009 (2009-01-01), pages 6258 - 6266 * |
| FENG, B. ET AL.: "Synthesis of Fe3O4/APTES/PEG diacid functionalised magnetic nanoparticles for MR imaging", COLLOIDS AND SURFACES A: PHYSICOCHEM. ENG. ASPECTS, vol. 328, 2008, pages 52 - 59 * |
| GE, Q. ET AL.: "Hydrophilic superparamagnetic nanoparticles: synthesis, characterisation, and performance in forward osmosis processes", IND. ENG. CHEM. RES., vol. 50, 2011, pages 382 - 388 * |
| HU, F. ET AL.: "Ultrasmall, water soluble magnetite nanoparticles with high relaxivity for magnet resonance imaging", J. PHYS. CHEM. C, vol. 113, 2009, pages 20855 - 20860 * |
| LI, Z. ET AL.: "One-pot reaction to synthesize biocompatible magnetite nanoparticles", ADV. MATER, vol. 17, no. 8, 18 April 2005 (2005-04-18), pages 1001 - 1005 * |
| LING, M. ET AL.: "Highly water soluble magnetic nanoparticles as novel draw solutes in forward osmosis for water reuse", LND. ENG. CHEM. RES., vol. 49, 2010, pages 5869 - 5876 * |
| PARK, J.Y. ET AL.: "Water-Soluble Ultra Small Paramagnetic or Superparamagnetic Metal Oxide Nanoparticles for Molecular MR Imaging", EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, 2009, pages 2477 - 2481 * |
| SUN, S. ET AL.: "Monodisperse MFe2O4 (M = Fe, Co, Mn) nanoparticles", J. AM. CHEM. SOC., vol. 126, 2004, pages 273 - 279 * |
| THEPPALEAK, T. ET AL.: "Synthesis of water dispersible magnetite nanoparticles in the presenc of hydrophilic polymers", POLYMER BULLETIN, vol. 63, 2009, pages 79 - 90 * |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US9447239B2 (en) | 2012-03-19 | 2016-09-20 | Samsung Electronics Co., Ltd. | Thermosensitive copolymers, forward osmosis water treatment devices including the same, and methods of producing and using the same |
| US20140151295A1 (en) * | 2012-11-30 | 2014-06-05 | Korea Institute Of Science And Technology | Plants for advanced treatment of wastewater and method for treating wastewater using thereof |
| WO2015076755A1 (en) * | 2013-11-21 | 2015-05-28 | National University Of Singapore | One-pot mass production of nanoparticles |
| CN103864179A (en) * | 2014-03-14 | 2014-06-18 | 厦门大学 | Forward osmosis extracting solution as well as preparation method and application thereof |
| CN103864179B (en) * | 2014-03-14 | 2015-09-02 | 厦门大学 | A kind of forward osmosis extracting solution and its preparation method and application |
| WO2015177391A1 (en) * | 2014-05-19 | 2015-11-26 | Consejo Superior De Investigaciones Científicas (Csic) | Nanostructured electrolyte useful for direct osmosis desalination, method for obtaining the electrolyte and uses of same |
| US10319502B2 (en) | 2014-10-23 | 2019-06-11 | Corning Incorporated | Polymer-encapsulated magnetic nanoparticles |
| WO2017051075A1 (en) | 2015-09-23 | 2017-03-30 | Kemira Oyj | Functionalized magnetic nanoparticles and a method for preparation thereof |
| US10726981B2 (en) | 2015-09-23 | 2020-07-28 | Kemira Oyj | Functionalized magnetic nanoparticles and a method for preparation thereof |
| EP3819018A1 (en) * | 2019-11-08 | 2021-05-12 | Nanogap Sub NM Powder, S.A. | Forward osmosis draw solute |
| WO2021089759A1 (en) * | 2019-11-08 | 2021-05-14 | Nanogap Sub Nm Powder, S.A. | Forward osmosis draw solute |
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