Processes for reducing the fouling of surfaces

Abstract

Process for reducing the fouling of a surface O, wherein an aqueous solution S of at least one polymer P comprising styrene and at least one ester E of (meth)acrylic acid and polyethylene oxide in a molar ratio of 0.05:1 to 50:1 is applied to said surface O.

Claims

1. A process for reducing fouling of a surface O, the process comprising: preparing an aqueous solution S comprising at least one polymer P formed from styrene and polyethylene glycol methacrylic ester by solution polymerization in water, ethanol, 1-propanol, isopropanol, or combinations thereof, wherein the aqueous solution S comprises at least 50% by weight of water; and applying the aqueous solution S to the surface O, wherein the polymer P has a number average molecular weight Mn of from 8,830 to 50,700 g/mol, wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of from 550 to 2,000 g/mol, and wherein the polymerization reaction is carried out using a molar ratio of styrene:polyethylene glycol methacrylic ester of from 20:1 to 1:4.

2. The process according to claim 1, wherein the surface O is a membrane M.

3. The process according to claim 1, wherein the polymer P has a number average molecular weight Mn of from 10,900 to 29,000.

4. The process according to claim 1, wherein the polymer P is a statistical copolymer.

5. The process according to claim 1, wherein the aqueous solution S comprises 0.001 to 1% by weight of said at least one polymer P.

6. The process according to claim 1, wherein the at least one polymer P is applied to the surface O in intervals of 1 day to 24 months.

7. The process according to claim 2, wherein the membrane M is a RO, FO, NF, UF or MF membrane.

8. The process according to claim 1, wherein said process is used in treating industrial or municipal waste water, sea water, brackish water, fluvial water, surface water or drinking water, desalination of sea or brackish water, dialysis, plasmolysis or processing of food and beverages.

9. The process of claim 1 wherein the solution polymerization occurs in water, ethanol, isopropanol, or combinations thereof, and the polymer P has a number average molecular weight Mn of from 10,500 to 18,500 g/mol.

10. The process of claim 1 wherein the solution polymerization occurs in a combination of water and 1-propanol.

11. The process of claim 1 wherein the solution polymerization occurs in a combination of water and isopropanol.

12. The process of claim 1 wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of 550 g/mol, the solution polymerization occurs in a combination of water and 1-propanol, and the polymer P has a number average molecular weight Mn of from 10,900 to 50,700 g/mol.

13. The process of claim 12 wherein the polymerization reaction is carried out using a molar ratio of styrene:polyethylene glycol methacrylic ester of 1:1.

14. The process of claim 1 wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of 1,000 g/mol, the solution polymerization occurs in a combination of water and 1-propanol, and the polymer P has a number average molecular weight Mn of from 10,900 to 50,700 g/mol.

15. The process of claim 14 wherein the polymerization reaction is carried out using a molar ratio of styrene:polyethylene glycol methacrylic ester of 1:1 to 1:4.

16. The process of claim 1 wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of 2,000 g/mol, the solution polymerization occurs in a combination of water and 1-propanol, and the polymer P has a number average molecular weight Mn of from 10,900 to 50,700 g/mol.

17. A process for reducing fouling of a membrane, the process comprising: preparing an aqueous solution S comprising at least one polymer P formed from styrene and polyethylene glycol methacrylic ester by solution polymerization in a combination of water and 1-propanol wherein the aqueous solution S comprises at least 50% by weight of water; and applying the aqueous solution S to the membrane M to form a layer of the at least one polymer P on the membrane, wherein the membrane M is a RO, FO, NF, UF or MF membrane, wherein the layer is a self-assembled monolayer, wherein the at least one polymer P is a statistical copolymer and has a number average molecular weight Mn of from 10,900 to 50,700 g/mol, wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of 2,000 g/mol, wherein the polymerization reaction is carried out using a molar ratio of styrene:polyethylene glycol methacrylic ester of from 20:1 to 1:4, and wherein the aqueous solution S comprises 0.001 to 1% by weight of the at least one polymer P.

18. The process according to claim 17, wherein the at least one polymer P is applied to the surface O in intervals of 1 day to 24 months, and wherein said process is used in treating industrial or municipal waste water, sea water, brackish water, fluvial water, surface water or drinking water, desalination of sea or brackish water, dialysis, plasmolysis or processing of food and beverages.

19. A process for reducing fouling of a membrane, the process comprising: preparing an aqueous solution S comprising at least one polymer P formed from styrene and polyethylene glycol methacrylic ester by solution polymerization in a combination of water and isopropanol, wherein the aqueous solution S comprises at least 50% by weight of water; and applying the aqueous solution S to the membrane M to form a layer of the at least one polymer P on the membrane, wherein the membrane M is a RO, FO, NF, UF or MF membrane, wherein the layer is a self-assembled monolayer, wherein the at least one polymer P is a statistical copolymer and has a number average molecular weight Mn of from 10,500 to 18,500 g/mol, wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of 2,000 g/mol, wherein the polymerization reaction is carried out using a molar ratio of styrene:polyethylene glycol methacrylic ester of 1:1, and wherein the aqueous solution S comprises 0.001 to 1% by weight of the at least one polymer P.

20. The process according to claim 19, wherein the at least one polymer P is applied to the surface O in intervals of 1 day to 24 months, and wherein said process is used in treating industrial or municipal waste water, sea water, brackish water, fluvial water, surface water or drinking water, desalination of sea or brackish water, dialysis, plasmolysis or processing of food and beverages.

21. A process for reducing fouling of a membrane, the process comprising: preparing an aqueous solution S comprising at least one polymer P formed from styrene and polyethylene glycol methacrylic ester by solution polymerization in a combination of water and 1-propanol, wherein the aqueous solution S comprises at least 50% by weight of water; and applying the aqueous solution S to the membrane M to form a layer of the at least one polymer P on the membrane, wherein the membrane M is a RO, FO, NF, UF or MF membrane, wherein the layer is a self-assembled monolayer, wherein the at least one polymer P is a statistical copolymer and has a number average molecular weight Mn of from 8,830 to 39,100 g/mol, wherein the polyethylene glycol methacrylic ester has a number average molecular weight Mn of 550 to 1,000 g/mol, wherein the polymerization reaction is carried out using a molar ratio of styrene:polyethylene glycol methacrylic ester of 1:1, and wherein the aqueous solution S comprises 0.001 to 1% by weight of the at least one polymer P.

22. The process according to claim 21, wherein the at least one polymer P is applied to the surface O in intervals of 1 day to 24 months, and wherein said process is used in treating industrial or municipal waste water, sea water, brackish water, fluvial water, surface water or drinking water, desalination of sea or brackish water, dialysis, plasmolysis or processing of food and beverages.

Description

EXAMPLES

(1) Abbreviations used:

(2) w. % % by weight PEGMA polyethylene glycol methacrylic ester PEGMA2000 polyethylene glycol methacrylic ester with an average molecular mass Mn of 2000 g/mol PEGMA1000 polyethylene glycol methacrylic ester with an average molecular mass Mn of 1000 g/mol PEGMA550 polyethylene glycol methacrylic ester with an average molecular mass Mn of 550 g/mol Sty styrene PEGA polyethylene glycol acrylic ester ATRP atom transfer radical polymerization Mn average molecular weight SEC size exclusion chromatography QCM quartz crystal microbalance PES polyethersulfone PVDF polyvinylidene difluoride PA polyamide PS polystyrene HEPES 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid UF ultrafiltration PWP pure water permeability RF.sub.coating flux recovery after coating FR.sub.fouling flux recovery after fouling h hour(s) s second(s) MWCO Molecular Weight Cut-Off
Number average molecular weights Mn were determined by gel permeation chromatography (Size Exclusion Chromatography) as follows:

(3) *Size Exclusion Chromatography was completed using a mixed bed scouting column for water soluble linear polymers, TSKgel GMPWxl from Tosoh Bioscience LLC, at 35 C. The eluent used was 0.01 M phosphate buffer at pH=7.4 containing 0.01 M sodium azide.

(4) The polymer used as 1.5 mg/mL concentrated solution in the eluent. Before injection in a 100 L injection loop, all samples were filtered through a Millipore IC Millex-LG (0.2 m) filter. The calibration was carried out with narrow polyacrylic acid sodium salt samples from PSS Polymer Standards Service having molecular weights between 900 to 1100000 g/mol, as well as using polyacrylic acid samples from American Polymer Standards Corporation with molecular weights of 1770 g/mol and 900 g/mol. Values outside this interval were extrapolated. For Mn calculations 3800 g/mol was fixed as the lower limit.

(5) When no other solvent is given in the experimental procedure, such experiments were carried out in water.

Example 1: Preparation of Copolymer X1 (Sty:PEGMA2000=1:4, Numbers in Header Give the Approximate Molar Ratio of the Components Used)

(6) 400.4 parts by weight of 1-propanol, 200 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, 1.3 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 10900 g/mol. A clear solution was obtained. After drying a white powder was recovered.

Example 2: Preparation of Copolymer X2 (Sty:PEGMA2000=1:1)

(7) 400.4 parts by weight of 1-propanol, 200 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, 5.2 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 11200 g/mol. A clear solution was obtained. After drying a white powder was recovered.

Example 3: Preparation of Copolymer X3 (Sty:PEGMA2000=4:1)

(8) 400.4 parts by weight of 1-propanol, 200 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, 20.8 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 25900 g/mol. A translucent solution was obtained. After drying, a white powder was recovered.

Example 4: Preparation of Copolymer X4 (Sty:PEGMA2000=10:1)

(9) 400.4 parts by weight of 1-propanol, 208 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, 52 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 50700 g/mol. A turbid solution was obtained. After drying, a white powder was recovered.

Example 5: Preparation of Copolymer X5 (Sty:PEGMA2000=20:1)

(10) 400.4 parts by weight of 1-propanol, 208 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol and added in the reactor at 70 C. within one hour. Additionally, 104 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 29100 g/mol. A turbid solution was obtained. After drying, a white powder was recovered.

Example 6: Preparation of Copolymer X6 (Sty:PEGMA1000=1:1)

(11) 400.4 parts by weight of 1-propanol, 208 parts by weight of PEGMA1000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, a mixture of 10.4 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 8830 g/mol. A clear solution was obtained. After drying, a white powder was recovered.

Example 7: Preparation of Copolymer X7 (Sty:PEGMA550=1:1)

(12) 400.4 parts by weight of 1-propanol, 220 parts by weight of PEGMA550 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, a mixture of 20.8 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 39100 g/mol. A clear solution was obtained. After drying, a clear viscous liquid was recovered.

Example 8: Preparation of Copolymer X8 (Sty:PEGMA1000=1:4)

(13) 400.4 parts by weight of 1-propanol, 200 parts by weight of PEGMA1000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, a mixture of 2.6 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. A clear solution was obtained. After drying, a white powder was recovered.

Example 9: Preparation of Copolymer X9 (Sty:PEGMA550=1:15)

(14) 400.4 parts by weight of 1-propanol, 200 parts by weight of PEGMA550 50 wt % water solution and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of 1-propanol were added in the reactor at 70 C. within one hour. Additionally, a mixture of 1.3 parts by weight of styrene in 180.7 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 in 100 parts by weight of 1-propanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of 1-propanol and 2 parts by weight of Wako V 59 were added during 6 h. The reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. A clear solution was obtained. After drying, a transparent viscous liquid was recovered.

Example 10: Preparation of Copolymer X10 (Sty:PEGMA2000=1:1) Via Emulsion Polymerization

(15) A solution of 0.7 parts by weight of styrene, 28 parts by weight of PEGMA2000 and 1.14 parts by weight of a universally applicable, non-ionic emulsifier for the manufacture of oil in water emulsions based on polyoxyethylene alkyl ethers prepared by the condensation of linear fatty alcohols derived from vegetable sources with ethylene oxide (Emulgin B2 PH) in 440 parts by weight of water were heated to 65 C. At 65 C. 0.5 parts by weight of sodium persulfate dissolved in 14 parts by weight of water were added to the reaction mixture while the temperature was increased to 80 C. at the same time. 10 minutes later 6.3 parts by weight of styrene, 25.2 parts by weight of PEGMA2000 and 1.8 parts by weight of Emulgin B2 PH in 180 parts by weight of water were added during 2.5 hours. At the same time, 1 part by weight of sodium persulfate dissolved in 80 parts by weight of water were added during 2.5 hours. The reaction mixture was kept at 80 C. for 5 hours. Then the reaction mixture was cooled to room temperature. A milky emulsion was obtained.

Example 11: Preparation of Copolymer X11 (Sty:PEGMA2000=1:1) Via Emulsion Polymerization without Emulsifier

(16) The experiment was carried out following the modified literature procedure described by A. Brindley S. S. Davis, M. C. Davies, J. F. Watts in the Journal of Colloid and Interface Science 1995, 171, 150-161. In a reactor 5.2 parts by weight of styrene were stirred (300 rpm) in 880 parts by weight of deionized water at 70 C. under nitrogen atmosphere. 216 parts by weight of PEGMA2000 50 wt % aqueous solution and 0.5 parts by weight of sodium persulfate were simultaneously added at 70 C., then the reaction medium was further stirred during 24 hours at 70 C., before being submitted to purification by water steam distillation. Mn found by SEC was 43100 g/mol.

Example 11A: Preparation of Copolymer X11A (Sty:PEGMA2000=1:1) Via Solution Polymerization in Toluene

(17) 300 parts by weight of toluene, 126 parts by weight of lyophilized (freeze dried) PEGMA2000 and 6.3 parts by weight of styrene were mixed under nitrogen and heated to 80 C. Afterwards, 2.65 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 15 parts by weight of toluene were added to the reactor at 75 C. The reaction mixture was kept at 80 C. for 24 hours. A clear solution was obtained. After cooling to room temperature, the polymer was purified by precipitation in 2-Methoxy-2-methylpropane (1500 mL MTBE). After drying in a vacuum oven at 40 C. overnight a white powder was obtained.

Example 12: Preparation of Copolymer X12 in Isopropanol (Sty:PEGMA2000=1:1)

(18) 400.4 parts by weight of isopropanol, 200 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of isopropanol were added in the reactor at 70 C. within one hour. Additionally, 5.2 parts by weight of styrene in 180.7 parts by weight of isopropanol and 2 parts by weight of Wako V 59 in 100 parts by weight of isopropanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of isopropanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 11300 g/mol. After drying, a white powder was recovered.

Example 13: Preparation of Copolymer X13 in Ethanol (Sty:PEGMA2000=1:1)

(19) 400.4 parts by weight of ethanol, 200 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of ethanol were added in the reactor at 70 C. within one hour. Additionally, 5.2 parts by weight of styrene in 180.7 parts by weight of ethanol and 2 parts by weight of Wako V 59 in 100 parts by weight of ethanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of ethanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 10500 g/mol. After drying, a white powder was recovered.

Example 14: Preparation of Copolymer X14 in Isopropanol (Sty:PEGMA2000=1:1)

(20) 300.4 parts by weight of isopropanol, 400 parts by weight of PEGMA2000 50 wt % solution in water and 0.025 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) were mixed under nitrogen and heated to 75 C. Afterwards 0.375 parts by weight of 2,2-azobis(2-methylbutyronitrile) (Wako V 59, Wako Chemicals GmbH, Germany) dissolved in 9.6 parts by weight of isopropanol were added in the reactor at 70 C. within one hour. Additionally, 5.2 parts by weight of styrene in 80 parts by weight of isopropanol and 2 parts by weight of Wako V 59 in 100 parts by weight of isopropanol were successively added within the next 2 hours. Thereafter, 100 parts by weight of isopropanol and 2 parts by weight of Wako V 59 were added during 6 h. The total reaction mixture was kept at 70 C. for another 2 hours, before being submitted to purification by water steam distillation. Mn found by SEC was 18500 g/mol. After drying, a white powder was recovered.

Example 15: Coating of Model Surfaces and Fouling Evaluation by QCM-D

(21) The Quartz-Crystal Microbalance with dissipation monitoring (QCM-D) measures the frequency of a freely oscillating quartz crystal after excitation, which scales inversely with mass changes at the surface of the sensor. The Q-Sense E4 (Biolin Scientific Holding AB) operating system has a mass sensitivity of about 2 ng/cm.sup.2. QCM measurements were performed using standard flow-through methods with a flow rate of 250 L/min at 23 C. A typical experiment comprised the following steps: 1) 10 mmol/L HEPES buffer pH 7 (=buffer) until a stable baseline was achieved; 2) 2 h 0.1 wt % polymer solution in buffer; 3) 2 h buffer; 4) 0.5 h 0.1 wt % milk powder in buffer; 5) 0.5 h buffer.

(22) Model polymer layers were generated on the QCM sensor surface by dip coating (for PES and PVDF), spin coating (for PS) or wet chemical reaction (for 1-Octadecanethiol). For dip-coating, the sensor was briefly immersed into a 1% solution of the respective polymer in N-methyl-pyrrolidone and subsequently dried at 200 C. using a heat gun. For spin-coating, a 40 L drop of 1% polymer solution in tetrahydrofuran was placed in the center of the quartz crystal and spread across the surface by spinning at 4000 rpm for 30 s. PA surfaces were obtained by coating on top of a PES layer via chemical modification: first, a drop of 1.5 wt % m-phenylenediamine was applied to the PES layer, followed by addition of about 1 mL 0.05 wt % of 1,3,5-benzenetricarbonyl trichloride; finally, the surface was rinsed with n-hexane. 1-Octadecanethiol layers were prepared by exposing gold-coated quartzes to a 1 mmol/L solution of the thiol in ethanol for 2 h, followed by rinsing with ethanol (35 mL) and subsequent drying in a stream of nitrogen. Adsorption of polymer on the model surfaces was carried out by equilibrating the modified quartz sensor surface with 0.1 wt % polymer solution in HEPES buffer until a monolayer was formed (step 2) above). Afterwards, the sensor surface was rinsed with buffer until a stable mass reading was obtained (step 3) above).

(23) Milk fouling was monitored during exposure of the samples to 0.1 wt % solutions of milk powder in HEPES buffer for 0.5 h. The final mass change was recorded after another 0.5 h of rinsing with buffer (steps 4) and 5) above). The results are given in Table 1.

(24) TABLE-US-00001 TABLE 1 QCM measurements of fouling caused by milk. Copolymer Polymer adsorbed adsorbed Milk adsorbed on the amount amount Fouling Example No. Model surface coated quartz [ng/cm.sup.2] ([ng/cm.sup.2]) wt % 15.1 PES / / 458 10 100% 15.2 PVDF 424 25 15.3 PA 404 30 15.4 PS 399 59 15.5 Octadecanethiol 375 59 15.6 PES X1 193 50 131 10 28.6% 15.7 PVDF 168 70 172 30 40.6% 15.8 PA 241 50 214 25 53.0% 15.9 PES X2 302 30 0 2 0.0% 15.10 PVDF 400 70 19 30 4.5% 15.11 PA 309 50 38 20 9.4% 15.12 PS 781 186 30 15 7.5% 15.13 Octadecanethiol 445 33 42 12 11.2% 15.14 PES X3 311 40 16 10 3.5% 15.15 PVDF 390 100 55 15 13.0% 15.16 PA 330 10 69 10 17.1% 15.17 PES X4 348 60 36 10 7.9% 15.18 PVDF 397 50 44 10 10.4% 15.19 PA 431 20 74 20 18.3% 15.20 PES X5 454 100 36 15 7.9% 15.21 PVDF 377 50 43 15 10.1% 15.22 PA 608 40 43 5 10.6% 15.23 PES X6 266 30 17 10 3.7% 15.24 PVDF 199 10 42 9 9.9% 15.25. PA 218 31 126 35 31.2% 15.26 PES X7 315 80 21 30 4.6% 15.27 PVDF 306 41 23 9 5.4% 15.28 PA 332 98 119 18 29.5% 15.29 PES X8 226 8 51 13 11.1% 15.30 PVDF 251 9 97 12 22.9% 15.31 PA 180 44 145 63 35.9% 15.32 Octadecanethiol 226 8 51 13 13.6% 15.33 PES X9 304 72 53 17 11.6% 15.34 PVDF 383 23 88 4 20.8% 15.35 PA 426 87 110 43 27.6% 15.36 Octadecanethiol 304 72 53 17 14.1% 15.37 PES X10 253 39 147 44 39.2% 15.38 PES X11 275 60 156 40 34.1% 15.39 PES X12 421 7 0 0% 15.40 PES X13 408 25 0 0% 15.41 PES X14 343 5 0 0% 15.42 PES X11A 335 67 69 24 15.1%

Example 16: Coating of Hollow Fiber Membranes and Fouling Evaluation by Monitoring the Pure Water Permeability (PWP)

(25) Single multibore ultrafiltration membranes based on polyethersulfone comprising seven bores per membrane (inge, Multibore 0.9, membrane diameter 4 mm, bore diameter 0.9 mm) were coated with a polymer monolayer by dipping for several hours (at least 2 hours) in a 0.1 wt % polymer solution in water, followed by an extensive rinsing with water to eliminate the polymer excess.

(26) Fouling with milk proteins (obtained from skim milk powder, Merck) was evaluated after dipping the blank and polymer coated single fibers in a 0.1 wt % of aqueous skim milk solution during at least one hour followed by extensive rinsing with water.

(27) Pure Water Permeability (PWP) of single 60 cm long Multibore hollow fibers was determined on blank membranes, on polymer coated membranes, and on both membrane types after milk fouling using 0.3-0.4 bar applied transmembrane pressure at room temperature. Flux Recovery (FR) was calculated: a) after polymer coating and b) after fouling with milk proteins using the following equations:

(28) $\begin{array}{cc}a)& {\mathrm{FR}}_{\mathrm{coating}}=\frac{{\mathrm{PWP}}_{\left(\mathrm{coated}\mathrm{membrane}\right)}}{{\mathrm{PWP}}_{\left(\mathrm{blank}\mathrm{membrane}\right)}}\\ b)& {\mathrm{FR}}_{\mathrm{fouling}}=\frac{{\mathrm{PWP}}_{\left(\mathrm{after}\mathrm{adsorptive}\mathrm{fouling}\right)}}{{\mathrm{PWP}}_{\left(\mathrm{before}\mathrm{fouling}\right)}}\end{array}$

(29) The results are given in Table 2.

(30) TABLE-US-00002 TABLE 2 Flux Recovery of uncoated multibore membranes and of multibore membranes coated with polymers X1 to X5. Coated polymer on hollow fiber Ex. Multibore membranes FR.sub.coating FR.sub.fouling 16.1 Blank (uncoated membrane) / 59% 1% 16.2 X1 41% 5% 90% 6% 16.3 X2 28% 1% 104% 1% 16.4 X3 37% 1% 93% 2% 16.5 X4 51% 3% 79% 0% 16.6 X5 57% 1% 73% 0%

Example 17: Coating of Flat Sheet Commercial Membranes and Fouling Evaluation by Monitoring the Pure Water Permeability (PWP)

(31) Commercial flat sheet ultrafiltration membranes based on polyethersulfone (Nadir UP150, UP050 and UP020) were dip-coated with a polymer monolayer during two hour immersion in a 0.1 wt % polymer solution in water, followed by an extensive rinsing with water to eliminate the polymer excess.

(32) Fouling with proteins was evaluated after dipping the blank and polymer coated membranes in a 0.02 wt % aqueous protein solution during one hour followed by extensive rinsing with water. PWP tests on flat sheet PES Nadir UP150, UP050, UP020 membranes were carried out in a dead-end cell at room temperature using 10 cm diameter commercial membranes, 1 bar fixed pressure, and 300-600 mL pure water.

(33) Flux Recovery was calculated: after polymer coating of membranes (Equation a), example 16) and after fouling with milk proteins (equation b), example 16):

(34) TABLE-US-00003 TABLE 3 Flux Recovery of uncoated flat sheet membranes and of flat sheet membranes coated with polymers X1 to X5. Coated polymer on flat sheet Ex. Nadir UP150 FR.sub.coating FR.sub.fouling 17.1 Blank (uncoated membrane) / 25.7% 17.2 X1 37.5% 58.9.1% 17.3 X2 32.2% 67.6% 17.4 X3 42.4% 58.7% 17.5 X4 52.7% 42.6% 17.6 X5 58.1% 43.7%

Example 18: Module Coating and Antifouling Efficiency of Small Modules in Midscale Convergence Test

(35) Filtration modules were prepared using three 20 cm long multibore ultrafiltration membranes based on polyethersulfone comprising seven bores per membrane (inge, Multibore 0.9, membrane diameter 4 mm, bore diameter 0.9 mm) assembled in a tube. Multibore hollow fibers were end-sealed within the tube by potting with epoxy resin.

(36) The coating procedure with a diluted 0.1 wt % X2 polymer solution using a peristaltic pump ISMATEC Type ISM444B included the following steps: 1) pure water rinsing of the module by 60 mL/min axial flux; 2) closing one end of the module and running pure water during 10 minutes through the membrane pores by 50 mL/min measured axial flux; 3) emptying of the module from water and filling it with a 0.1 wt % X2 polymer solution in water, which is rinsed 90 minutes through the bores at 70 mL/min axial flux; 4) closing one end of the module and running the polymer solution during 10 minutes through the membrane pores by 50 mL/min axial flux; 4) opening of both module ends and rinsing it again with a 0.1 wt % X2 polymer solution during 30 minutes; 5) closing the module containing the polymer solution (both module ends are sealed) over night.

(37) Blank and coated modules were submitted to a 40 hours defined fouling test in a Convergence InspectorModel Dialysis/UFR system (Convergence Industry B.V).

(38) The Convergence system was run with 0.01 wt % milk protein solution (i.e. obtained from skim milk powder Merck) at 3 kg/h constant feed under dead-end conditions. A backwash with pure water was applied every 20 seconds, followed by a chemical enhanced backwash (CEB) using 30 mmol/L sodium hydroxide solution set to occur when the transmembrane pressure (TMP) reached the maximum value of 0.8 bar. The variations in TMP were recorded against time for both the coated and the uncoated module.

(39) The total number of required CEB and the total amount of produced water were calculated for a module containing blank membrane (Example 18.1) and for the polymer coated module (Example 18.2) are given in Table 4.

(40) TABLE-US-00004 TABLE 4 Total number of required CEB and the total amount of produced water for coated and uncoated membrane modules Total number of Total amount of produced Ex. Module type required CEB water (kg) 18.1 Blank module 40 63 18.2 Coated module 10 106

(41) Total amount of water produced was 68% higher for the coated module.

Example 19: Pore Size EffectCoating of Flat Sheet Membranes with Decreasing Pore Sizes and Fouling Evaluation by Monitoring the Pure Water Permeability (PWP)

(42) Ultrafiltration Flat sheet commercial PES Nadir UP150, UP050 and UP020 membranes with different pore sizes given in Table 5 were coated with the X2 polymer following the procedure detailed in example 17.3.

(43) Fouling with milk proteins (obtained from skim milk powder, Merck) was evaluated after dipping the blank and polymer coated single fibers in a 0.1 wt % of aqueous skim milk solution in water during at least one hour followed by extensive rinsing with water. Flux Recovery was calculated: after polymer coating of membranes (Equation a), example 16) and after fouling with milk proteins (equation b) example 16). The results are given in Table 5.

(44) TABLE-US-00005 TABLE 5 Flux Recovery of flat sheet membranes with different pore sizes coated with polymers X2 Nadir (MWCO) membrane type (kDa) FR.sub.coating FR.sub.fouling UP150 150 44% 16% 41% 12% UP050 50 31% 1% 33% 1% UP020 20 45% 4% 44% 4%

Example 20: Monolayer Formation and Analysis Monitored by AFM

(45) Tapping Mode

(46) The AFM cantilever is driven by an external actuator at a frequency close to its first flexural resonance frequency and scanned over the surface in a rastering process. As the cantilever is brought close to the surface interaction forces on the nanometer scale arise which dampen the cantilever oscillation. During the measurement, the cantilever height was adjusted by a feed-back control in order to keep the oscillation amplitude constant. This provides a topography image of the surface.

(47) Interaction forces between the cantilever tip and the sample, both mechanical as well as physicochemical in nature, directly affect the phase shift between the external excitation signal of the actuator and the cantilever response. The phase image thus directly relates to material properties and provides information on a mix of elastic modulus, visco-elastic, and adhesion properties and offers a qualitative material contrast.

(48) For all measurements standard AFM Silicon-tips OMCL-AC160TS from Olympus were used (k=42 N/m, f.sub.0=300 kHz). All images were obtained using the tapping-mode with constant amplitude attenuation. For each sample, topography and phase images where obtained at a scan rate of 0.8 Hz and were recorded with a scan size of 11 m.sup.2 and a standard resolution of 512512 pixels.

(49) FIG. 1 shows Tapping-mode AFM material contrast images of the identical spot on a Nadir UP150 membrane before (A) and after (B) adsorptive coating with polymer X3. The coating procedure was carried out on flat sheet PES Nadir UP150 analogous to example 17.4.

(50) Topography and phase shift images shown in FIG. 1 were measured using a MFP-3D Atomic Force Microscope (AFM). Images clearly show that a thin layer of a polymer was adsorbed to the porous membrane surface. The layer seems homogeneous, yet thin, as individual pores of the membrane could still be discerned.

(51) Colloidal Probe AFM

(52) Force measurements with the AFM were performed by the colloidal probe technique, where the sharp tip was replaced by a micrometer sized colloidal sphere to improve force sensitivity in nanomechanical measurements and allow for a quantitative analysis of the interaction force, as described in Butt et al., Surface Science Reports, 2005, 59, 1-152. By choosing an appropriate chemical modification of the colloidal probe specific interaction forces, could be measured.

(53) Colloidal Probe measurements were performed on a MFP-3D AFM software version IGOR 6.11. For measurement colloidal probes made of 1) polystyrene, radius 3.3 m (Polybead Microspheres), 2) silica, radius 3.2 m (Silica Microspheres), 3) amino functionalized, radius 3.1 m (Polybead Amino Microspheres) were used. The probes were glued to tip-less cantilevers (HQ:CSC38 type A from Fa MikroMasch, k=0.09 N/m) using a 2K epoxy from UHU (UHU plus 300). The probes were dried and hardened for 24 h at room temperature. Force distance curves were performed at ramp speeds of 1 Hz in relative trigger mode (max load 5 nN) and a dwell time of Os. Nadir UP150 membrane samples were immersed for two hours in respective aqueous solutions prior to colloidal probe measurements. In the case of coated membranes, the samples were stored in a 0.1 wt % solution of X3 polymer in water for two hours. Samples were rinsed thoroughly with water to remove excess polymer prior to colloidal probe measurements.

(54) Force-Distance Curves of an OH functionalized, a NH2 functionalized and polystyrene colloidal probes (3.2 m, 3.1 m and 3.3 m diameter respectively) were recorded in 1 mM NaCl solution at pH=7.3 on approach against a blank Nadir UP150 membrane and a Nadir UP150 coated with polymer X3. The partially negatively charged PES membrane surface attracts the amino functionalized probe on approach, as is evident in the observed snap-in (negative or attractive interaction force) at a distance of a few nanometers to the surface. On the other hand, no attractive interaction is observed in the case of the OH terminated, as well as the polystyrene probe. Upon coating with X3 polymer a steric penalty is added and all probes independent of their chemistry or partial surface charge experience a repulsive force upon approach, which is more pronounced for the hydrophilic probes than hydrophobic ones.

(55) Besides an introduction of steric repulsion on approach, the Sty:PEGMA coating also reduces the adhesiveness.

(56) The cumulative distribution function for adhesion of a NH2 functionalized and a polystyrene colloidal probe were recorded in 1 mM NaCl solution at pH=7.3 against a blank Nadir UP150 membrane and a Nadir UP150 membrane coated with polymer X3.

(57) The cumulative distribution function for adhesion of a NH2 functionalized colloidal probe, representing a hydrophilic moiety, on a blank Nadir UP150 membrane is very broad ranging from a few nN/m to 4.5 mN/m, with a variable slope. d100.1 mN/m, d500.6 mN/m and d903 mN/m. This curve is dramatically shifted towards lower adhesion reaching 100% already at 0.1 mN/m once the Sty:PEGMA coating is applied.

(58) This implies that both the modes of interaction, which is indicative of a uniform functionalization of the Nadir UP150 membrane, as well as the magnitude of interaction or adhesiveness, are dramatically reduced. The polystyrene probe which serves as an example of a hydrophobic moiety adheres less strongly to the native Nadir UP150 membrane but still sticks (100% reached at 0.5 mN/m). Further, after coating the Nadir UP150 membrane with polymer X3 adhesion of hydrophobic moieties of the polystyrene probe is strongly reduced (100% reached at <0.1 mN/m).