COMPOSITION ANTIFOULING COATING: EFFECT...

Danail Akuzov, Todorka Vladkova, Anne Klöppel, Franz Brümmer, Sriyuta Murthy

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Journal of Chemical Technology and Metallurgy, 49, 3, 2014, 229-237

COMPOSITION ANTIFOULING COATING: EFFECT OF SILOXANE AND FLUORINATED OIL INCORPORATION ON MARINE BIOFILM FORMATION

Danail Akuzov1, Todorka Vladkova1, Anne Klöppel2, Franz Brümmer2, Sriyuta Murthy3

1 Department of Polymer Engineering, University of Chemical Technology and Metallurgy, Sofia, Bulgaria E-mail: [email protected] Faculty of Energy Technology, Process Engineering and Biological Engineering, Stuttgart University, Germany3 Biofouling&Biofilm Processes Section, Water and Steam Chemistry Division, BARC Facilities, IGCAR Campus, Kalpakkam, India

ABSTRACT

Composition polysiloxane based coatings are currently the only viable commercial alternative of the toxic biocide containing antifouling paints. Oil incorporation improves the foul-releasing ability of the polysiloxane coatings. The im-pact of non-reactive, different molecular mass, both siloxane and fluorinated oil on the biofilm formation onto developed by us polysiloxane composition coating is presented. It is evaluated in laboratory and field experiments on the ground of the determination of the elastic modulus, water contact angle, critical surface tension, surface roughness and topography.

Keywords: composition poly(siloxane) antifouling coating, siloxane and fluorinated oil incorporation, effect on marine biofilm development.

Received 02 December 2013Accepted 09 April 2014

INTRODUCTION

In response to the restriction of biocide containing paints applycation, new antifouling strategies are under development. They are based on employment of materials with inherently deterrent surface properties, amphiphilic surfaces and new fluoro-polymer coatings with surface micro- and nano-topography [1, 2]. Secondary metabolites of marine organisms [3-5], like organic acids, steroids, terpenoids, amino acids, alkaloids, polyphenols, acetogenins and heterocyclics (furans and lactones) [6-8], zosteric acid [9], etc. that can act as natural biocides or biosurfactants [4, 10] are also of special interest. But each one of them has some advantages and disadvantages.

Siloxane foul-release coatings creating low adhesive surfaces remain the only viable commercial alternative

of the toxic antifouling paints. Additional improvement of their foul-releasing ability is achieved by including oils in their compositions [11]. Later studies [12-16], focused on the decrease of the adhesion strength of fouling organisms and substrate surfaces by including different linear and branched oils confirm their ability to improve the biofouling release. Higher molecular weight perfluoropolyethers are also included in some formulations for easy-release coatings [17 - 19]. The incorporated oil amount is usually of 5-10 mass % although Hoipkemer et al [20] find increase in spore-lings extraction (detachment) at relatively high loading levels (at 20 mass % and above) of non-reactive poly(dimethylesiloxane) oil in siloxane elastomers. The non-bonded oil migrates on the surface, creating continuous [21] weak, lubricant-like layer that alters the friction and hence influences the biological adhesion

Journal of Chemical Technology and Metallurgy, 49, 3, 2014

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[22 - 24]. The oils alter also the elastic modulus of the coating that is a release favoring factor [25, 26]. Some oils alter the hydrophobicity during both, the vulcanization process and the subsequent exposure in the sea [13, 26]. The oils increasing surface hydrophobicity (like phenyl-containing or fluorinated oils) improve releasing capacity of the coating [15]. The improved fouling-release performance of the oil-containing coatings could be due to inhibited bio-adhesive cross-linking, indicated as contact angle anomalies [27].

Although the poly(siloxane) coatings inhibit the macro-fouling settlement, they suffer from persisting colonization by slime [28], even at speeds grader than 50 knots. The slime is unaffected by turbulence effects. It remains on the surface increasing the fuel consump-tion, CO2 emission, and has negative impact on many underwater constructions [29]. The releasing ability of siloxane antifouling coatings depends [30] on elastic modulus, hydrophobicity, critical surface tension and topography which in turn depend on oil incorporation. The impact of oils on the biofilm formation is less investigated and so far irrespective of the very active research, a perfect antifouling solution is not found [31].

Biocides-free, siloxane composition coating is developed by us [32]. It prevents macro-biofouling of high and low speed (below 14 knots) moving vessels and even static immersed underwater constructions. Its anti-fouling performance can be improved reducing the biofilm formation by incorporation of oil that can act also as a carrier of some low-toxic anti-biofilm additives [33]. The aim of this study is to evaluate the effect of different molecular weight non-reactive siloxane and fluorinated oil on the elastic modulus, hydrophobic-ity, surface tension, topography and roughness, of the siloxane antifouling coating [32].

EXPERIMENTAL

Siloxane composition coating and test samples preparation

Siloxane composition coating based on a combina-tion of room temperature vulcanizing (RTV) siloxane elastomers and fillers, cross-linking agent, catalyst and oil was prepared as described in ref. [32]. It was further noted as a control. The oil type and amount were var-ied as pointed below. Test samples (10x15x0.3 cm and 6x6x0.3 cm) were prepared after curing for a week at

room temperature. The testing was performed after at least 4 weeks keeping preserving the conditions aiming to acheave complete cross-linking.

OilsTwo types of non-reactive oils, siloxane (SO) and

fluorinated (FO) oil, were employed for this investiga-tion. Both were of different chain length. The absebce of terminal -OH groups in the SO is the only difference from the siloxane rubber used as elastomeric base of the composition coating studied. SO with four different viscosities, (given as an index) and chain lengths were used in this investigation:

It was expected that migrating on the coated surface, the non-reactive fluorinated oil would form highly hy-drophobic layer. Fluorinated oils Krytox (DuPont, USA) of different chain length were used for this study. The last ones were low molecular weight, fluorine end-capted, homopolymers of hexafluoropropylene epoxyde with the following chemical structure:

These fluorinated oils are biologically inert, not metabolized, not biodegradable, non-soluble, non-toxic and do not support any type of biological growth.

Elastic modulus estimationElastic modulus of 3 mm thick vulcanized test

samples of the siloxane composition was estimated

Siloxane oil Dynamic Viscosity, Molecular Mass

cP

SO 100 100 5970 (n = 80)

SO 350 350 13650 (n = 184)

SO 1000 1000 28000 (n = 378)

SO 10000 10000 62700 (n = 847)

Fluorinated oil Kinematic Molecular mass

viscosity, cSt

FO 10 (Krytox GBF 101B) 10 1800 (n=10)

FO 30 (Krytox GPL 105) 160 5100 (n=30)

FO 60 (Krytox GPL 107-500) 500 10100 (n=60)

F-(CF-CF2-O)n-CF2CF3, where n = 10, 30 and 60

CF3


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according to ISO 88.Contact angle measurement and surface tension

calculationContact Angle Measuring Instrument Easy Drop

(Kruss, Germany) was employed for contact angle measurement (angle resolution ±0.1°) using three liquids with known surface tension: water, ethylene glycol and n-hexadecan. Surface tension was calculated according to the Fowkes method [34].

SEM observationMorphological observations were performed on gold

pre-coated samples using LYRA TESCAN microscope (Czech).

Surface roughnessSurface profile images of the samples (1 cm2) were

obtained by tapping mode AFM device, Nanoscope-3 Digital Instrument, Santa Barbara, equipped with sili-cone mono-crystal type, model TESP with deformation constant of 0.58 N/m and working at 1Hz scanning frequency. Arithmetic mean roughness (Ra) and root mean square roughness (Rq) was calculated using data processing unit.

Exposure to biofoulingThe settlement was carried out in Mediterranean

environment aquarium corresponding to the ecology parameters of Limski Channel, Mediterranean Sea [33]. The samples were fixed on a common plane plate and vertically dipped in the aquarium at a distance of 10 cm from its front wall. Two lamps (54 W, Power chrome pure actinic, Giesemann) were employed to supply UV light (l< 380 nm) necessary for the TiO2 activation. Thin mat polyethylene foil was used for obtaining of diffuse light. The lighting was of 40x103 Lx as measured with GOSSEN Panlux electronic 2 lux-meter. The exposure duration was of 5 weeks. This period was long enough for complete biofilm formation in “warm” marine water as the Mediterranean Sea. After that the samples were taken out and each sample (6x6x0.3 cm) was placed in a Perty dish and kept at 80C in a refrigerator. Field exposure was carried out at Fishing Harbor, Chennai, India up to 7 days when the biofilm formation is com-pleted. Triplicate samples (10 x 15 x 0.3 cm) were used for each test.

Biomass collection and homogenization Biofilm of each laboratory sample was carefully

removed (by means of metal spatula) and placed in a 15 ml Falkon type test-tube. 5 ml distilled water was

added to each test-tube. Homogenization of the biofilm mass was performed for 5 min, directly in the test-tube by dipping an ultrasound rood (Bandelin electronic UW 3100) and cooling in ice bath. Biofilm of each field sample was scraped, dispersed in a fixed volume of 0.22 mm milipore-filtered autoclaved seawater and used in this form for further analyses.

Biofilm characterizationTotal chlorophyll (chlorophyll A, and chlorophyll

B) and carotenoids (carotenes and xanthophylls) estimation

The total chlorophyll (chlorophyll A, chlorophyll B) as well as the carotenoids amount was estimated spectro-metrically from an ethanol extract employing Pharmacia Biotech Ultra-spec 3000 apparatus. Extraction of the pigments from the biofilm mass was performed as fol-lows: 1 ml from the biofilm suspension was carefully, drop by drop placed onto glass filter (pore size of 1.6 mm). The reach of pigments cell elements were hold on the filter and each filter was placed in 2 ml “Eppis” type centrifuge test-tube. 1.5 ml of 95 % ethanol was added and the containers were dark-kept for 24 h under mixing on KIKA KS250 (Labortechnik Shaker). The complete extraction was followed by 5 min centrifuging at 28 000 G for the extract clearing. 1 ml from each clear extract was used for spectrometerically determinations: at l470 nm – to calculate the carotenoids content; l649 nm – to calculate the chlorophyll B content; l664 nm – to calculate the chlorophyll A content; l730 nm – turbidity estimation and other absorbance’s correction.

Biofilm dry mass The biofilm dry mass was estimated gravimetrically

using the following procedure: 3 ml from each suspen-sion were placed in a Falкon test-tube (dried for 24 h at 105oC and conditioned for 4 h at normal conditions) and centrifuged at 5200 G for 5 min. The liquid phase was separated and 5 ml isopropanol (99.7 %) were added to remove the siloxane oil out of sediment. After centri-fuging and the isopropanol separation the test-tube with the sediment was dried for 5 h at 90oC and conditioned for 4h at room temperature then the weight (±0.0001 g) was found. The biofilm dry mass was estimated as a difference between the value of this weight and that of the empty test-tube.

Total suspended solids (TSS, mg/l)A known volume of a sample was filtered through

a standard GF/C glass filter. The residue retained on the


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filter was dried at 1050C and ±0.00001 g balance weight.Microbiological analysisMicrobiological analysis was carried out using

standard media pack from HIMEDIA LABORATORIES (Mumbai, India). Total viable count (TVC) was enumer-ated using Zobell Marine Agar 2216 (HIMEDIATM) by the pour plate technique.

Assessment of biomass contents by adenosine triphosphate (ATP, ng/ml)

20 ml of asample was placed thorough a 0.2 µm Millipore filter, then was extracted in 4 ml of boiling Tris buffer (HiMediaTM Laboratories, Chennai, India) and the ATP content was determined based on the firefly bioluminescence reaction [35]. The generated light signal (Relative Light Units, RLU) was measured after seconds-delay time and tenths-integration time with Sirius Luminometer D-75173, Berthold Detection Systems GmbH. The concentration of ATR was determined from RLU values with reference to the ATP standard [36].

RESULTS AND DISCUSSIONParameters relevant to releasing ability Elastic modulus, water contact angle, surface

tension and surface roughness are generally accepted as parameters, relevant to the releasing ability of the biocides-free antifouling coatings [30]. These parameters for the studied vulcanized siloxane composition coating are presented in Fig. 1 and Table 1 as depending on the presence of SO, FO or their 1:1 (v/v) combination.

The elastic modulus decreases in presence of SO (Fig. 1), depending on its amount and viscosity (molecular weight). The curves in Fig. 1 show that

Fig. 1. Elastic modulus of vulcanized antifouling siloxane composition containing 0-30 mass % siloxane oil with dif-ferent viscosity, cPa: 100 (curve 1); 350 (curve 2); 1000 (curve 3) and 10000 (curve 4).

Table 1. Characteristics: elastic modulus, E, MPa; water contact angle, q H2O; critical surface tension, g , mN/m; arithmetic, Ra, nm and square Rq, nm surface roughness of biocides-free siloxane antifouling coating without oil (control) or contain-ing siloxane oil (SO), fluorinated oil (FO) oil or 1:1, mass % SO 350/FO 30.

Sample No

Oil content, mass % E, MPa

qH2O, 0 gc, mN/m

Ra, nm

Rq, nm

Control 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

0

SO 100 30 SO 350 30 SO 1000 30 SO 10000 30

FO 10 10 FO 30 10 FO 60 10

SO 350 5 FO 30 5 1:1 mass% SO 350/FO30 5

SO 350 10 FO 30 10 1:1 wt.% SO 350/FO30 10

0.53

0.22 0.26 0.30 0.28

0.40 0.39 0.41

0.31 0.49 0.41

0.29 0.39 0.34

98.6

100.3 102.1 102.9 103.1

106.7 108.1 107.5

101.2 108.3 106.1

103.0 107.5 105.5

28.31

23.96 24.09 24.12 23.69

21.62 19.63 20.48

24.00 20.69 22.92

24.24 19.63 23.79

33.46

31.69 26.93 24.99 20.64

35.17 43.34 32.99

30.12 42.58

8.7 -

43.34 22.21

41.11

40. 99 36.22 37.35 31.79

36.12 49.09 35.00 39.31 50.16 10.49

-

49.09 33.22


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the decrease corresponds to decrease of the viscosity/molecular weight of the SO. Their slop indicates that the decrease is better outlined in the concentration range up to ca. 10 mass %. This explains way relatively low loading levels (of 5-10 mass %) low molecular weight SO are usually preferable. The oil of the highest viscosity (curve 4) is an exception in this case where the decrease is proportional to the oil amount in the whole concentration range studied.

As it is evident from Table 1 the viscosity of the oils used in this study affects insignificantly the hydrophilic/hydrophobic balance on the coating surface (the water contact angle of about 100.3-103.10 for all samples) and the surface tension (of about 23.69 – 24.12 mN/m for all samples). In fact the latter falls in the Bayer window of 20-30 mN/m which is generally accepted as the best regarding the releasing ability of the antifouling coatings [33]. The addition of 30 mass. % SO decreases significantly the elastic modulus of the control sample down to 0.28-0.22 MPa depending slightly on the viscosity of the SO used.

FO Krytox of different chain length (different viscosity and molecular weight) correspondingly: FO 10, FO 30 and FO 60 were used in this experiment. As evident from Table 1 (samples 5 – 7) the presence of

10 mass % of FO 10, FO 30 and FO 60 decreases the elastic modulus of the control sample down to 0.41-0.39 MPa. The water contact angle of these samples of 106.70, 107.50 and 108.10, respectively is higher as compared to that of the control sample. The surface tension, gc of 21.62-19.63 mN/m is significantly lower when compared to that of the control sample.

Table 1 (sample 8-13) shows comparative data on the effect of SO 350 and FO 30 as well as SO 350/FO 30 (1:1, mass %) combination at a loading level of 5 and 10 mass %. It is seen that the elastic modulus, E is well decreased in presence of SO 350 while the water contact angle, qH2O is significantly increased of in presence of FO 30 at both loading level of 5 mass % and 10 mass %. It can be concluded that the oil containing compositions have lower elastic modulus when compared to that of the oil-free sample while those containing SO 350 have lower elastic modulus compared to that of the samples loaded with the same amount of FO 30 or combination SO 350/FO 30. The compositions, containing 5 wt. % or 10 mass % of FO 30 or its combination with SO 350 are characterized with higher water contact angle, qH2O

and lower surface tension, gc compared to those of the composition, containing the same amount of SO 350. The water contact angle is affected by the surface rough-

Fig. 2. SEM picture of: (a) - control (without oil), and the same composition with included 10 mass % (b) - SO 350, (c) - FO 10, (d) - FO 30 and (e) - FO 60.


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ness depending on the oil type and amount.Surface morphologySEM observation shows the surface morphology of

the vulcanized control composition (Fig.2 a), of those containing 10 mass % SO 350 (Fig. 2b), FO 30 (Fig. 2c),

Fig. 3. Parameters of developed in Mediterranean aquarium biofilm: (a) total chlorophyll, μg/cm2; (b) carotenoids content, μg/cm2; (c) dry mass, μg/cm2, on a control composition coating (the first column) and such loaded with 30 wt. % silox-ane oil with different viscosity/molecular weight: SO 100, SO 350, SO 1000 and SO 10000 (the group of four columns).

Fig. 4. Biofilm parameters: (a) total suspended solids (TSS, mg/l); (b) total viable bacterial count (TVC, CFU/cm2), (c) biomass content, assessed by adenosine triphosphate (ATP, ng/ml, developed on sample containing 10 mass % fluorinated oil with different chain length (molecular mass): FO 10, FO 30 and FO 60 after 7 days of exposure in Fishing harbor, Chennai, India.

FO 60 (Fig. 2d) and FO 60 (Fig. 2e), correspondingly. The comparison of Fig. 2a and Fig. 2b shows lack of significant alteration of the surface morphology of the control composition (Fig. 2a) by including SO (Fig. 2b). SO forms a thin homogeneous layer, not observed in Fig.


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2b due to its transparency. No morphological differences are observed in case of samples containing SO 100, SO 1000 and SO 10000. That is way in additional pictures is not presented here. When FO is included in the studied composition coating, droplets on the surface of a micron size are observed (Fig. 2c, d, e) due to very low surface tension of the migrated FO.

Biofilm characterizationThe effect of SO molecular weight/viscosity at a

loading level of 30 mass % is outlined in Fig. 3. It is evaluated by total chlorophyll (Fig. 3a), carotenoids (Fig. 3b) and dry biofilm mass (Fig. 3c). It is seen, that the scare biofilm on the control sample is additionally decreased by SO inclusion. The first column in Fig. 3a, b, and c corresponds to the control sample (without oil). It is higher when compared to that of the columns corresponding to when 30 mass % SO presence. The biofilm decrease is best outlined for SO 350 and SO1000 (molecular weight of 13500 and 28000, correspondingly). The total chlorophyll (Fig. 3a) and carotenoids content (Fig. 3b) is lower for the composition coating containing SO 1000, whereas the total dry biofilm mass (Fig. 3c) is lower for the composition containing SO 350. The latter is characterized by the lowest surface roughness (Table 1, sample 2).

Fig. 4 shows the biofilm parameters: (a) total suspended solids (TSS, mg/l); (c) biomass content, assessed by adenosine triphosphate (ATP, ng/ml); and (b) total viable bacterial count (TVC, CFU/cm2), developed on substrates containing 10 mass % fluorinated oil FO 10, FO 30 and FO 60 after 7 days exposure in Fishing harbor, Chennai, India. A comparison of the three columns in Fig. 4a, Fig. 4b and Fig. 4c demonstrates the

sensitivity of the total suspended solids, TSS (a), biomass content (c) and total viable count (b) to the FO chain length (molecular mass). The composition containing 10 mass % FO 30 shows a promising trend by low total suspended solids, TSS and TVC.

The main micro settlement on siloxane antifouling coatings exposed in Indian Ocean consists of diatoms, as found in previous experiments [30]. The next Fig. 5 presents the diatom counts accumulation on the control siloxane composition coating (Fig. 5, curve 1) and coatings with added 10 mass % of SO 350 (Fig. 5, curve 2) and FO 30 (Fig. 5, curve 3). The kinetic diatom counts accumulation at the surface of the control sample (curve 1) and those containing SO 350 (curve 2) and FO 30 (curve 3), indicates differences in the initial attachment of diatoms to the surfaces studied.

CONCLUSIONSNon-reactive siloxane and fluorinated oils affect

marine biofilm formation through antifouling siloxane composition coating. The siloxane oil forms a homo-geneous thin surface layer, whereas the fluorinated oil forms leached surface droplets. This should be taken into account when oil is used as anti-biofilm agent carrier.

The effect of the siloxane oil is dependent on its viscosity and molecular weight. The latter affects mainly the elastic modulus and surface roughness. Optimal oil viscosity (molecular weight) regarding marine biofilm reduction is of 350 - 1000 cPa (Mw = 13500 - 28000), as found in a laboratory experiment.

The effect of the fluorinated oils is dependent on their chain length and viscosity/molecular weight. The latter affects mainly the size of the oil droplets, the specific surface topography and created surface rough-ness. The elastic modulus is insignificantly depending on the chain length.

The kinetic curves of diatom counts accumulation indicate the existence of differences in the initial adhe-sion on the studied surfaces.

Acknowledgements The authors gratefully acknowledge the financial

support of Fund Scientific Investigations, Bulgaria and DAAD (grant No DNTS 01/6/15.11.2011.) in the frame of bilateral Bulgarian-German contract. DuPont (USA) is gratefully acknowledged for a free of charge supply of Krytox fluorinated oils.

Fig. 5. Diatom counts accumulation on a control siloxane composition coating (curve 1) and such containing 10 mass % SO 350 (curve 2) or the same amount FO 30 (curve 3) during one week exposure in Indian Ocean, Fishing harbor, Chennai.


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REFERENCES

1. D.C. Webster, B.J. Chisholm, New Directions in Antifouling Technology, In Biofouling (Eds S. Dürr & J.C. Thomason), Wiley-Blackwell, 2010, p. 366-369.

2. D. Rittschof, Research in Practical Environmentally Bening Antifouling Coating, In Biofouling (Eds S. Dürr & J.C. Thomason), Wiley-Blackwell, 2010, p. 396-400.

3. S. Abarzua, S. Jakubowsky, Biotechnological investi-gation for the prevention of biofouling. I. Biological and bio-chemical principles for the prevention of bio-fouling, Mar. Ecol. Prog. Serv., 123, 1995, 301-312.

4. D. Rittschof, Natural product antifoulants: one per-spective on the challenges related to coatings develop-ment, Biofouling, 15, 1, 2000, 119-127.

5. T. Vladkova, D. Akuzov, A. Klöppel, F. Brümmer, Current Approaches to Reduction Marine Biofilm Formation , J.Chem.Technol.Metall., 2014 – in press.

6. S. Clare,Towards nontoxic antifouling, J. Mar. Biotechnol., 6, 1998, 3-9.

7. N. Fusetani, Marine natural products influencinglar-val settlement and metamorphosis of benthic inver-tebrates, Curr. Org. Chem., 1, 1997, 127-152.

8. M.E. Hay, Marine chemical ecology: what‘s known and what‘s next? J. Exp. Mar. Biol. Ecol., 200, 1996, 103-134.

9. M.G. Callow, J.A. Callow, Marine biofouling: A sticky problem, Biologist, 49, 2002, 1-5.

10. P.D. Steinberg, R. Nys, S. Kjelleberg, Chemical inhibition of epibiota by Australian seaweeds, Biofouling, 12, 1, 1998, 227-244.

11. A. Milne, Antifouling marine compositions, US Patent 4025 639/1977.

12. J. Stein, K.Truby, C.D. Wood, J. Stein, M. Gardner, G. Swain, C. Kavanagh,

13. B. Kovach, M. Schultz, D. Wiebe, E. Holm, J. Montemarano, D. Wendt, C. Smith, A. Meyer, Silicone Foul Release Coatings: Effect of the Interaction of Oil and Coating Functionalities on the Magnitude of Macrofouling Attachment Strengths Biofouling, 19, Supplement 1, 2003, 71-82.

14. K. Truby, C.Wood, J. Stein, J.Cella, J. Carpenter, C. Kavanagh, G. Swain, D.Wiebee, D. Lapota, A. Meyer, E. Holmi, D. Wendt, C. Smith, J. Montemarano, Evaluation of the performance en-hancement of silicone biofouling, release coatings

by oil incorporation Biofouling, 15, 1-3, 2000, 141-150.

15. R.F. Brady, Clean Hulls without Poisons: Devising and Testing Nontoxic Marine Coatings, J. Coat. Technol., 72, 2000, 45-56.

16. C.J. Kavanagh, G.W. Swain, B.S Kovach, J. Stein, C. Darkangelo-Wood, K. Truby, E. Holm, J. Montemarano, A. Meyer, D. Wiebe, The effects of silicone fluid additives and silicone elastomer matrices on barnacle adhesion strength, Biofouling, 19, 6, 2003, 381-390.

17. A.W. Feinberg, A.L. Gibson, W.R. Wilkerson, C.A. Seegert, L.H. Wilson, L.C. Zhao, R.H. Baney, J. A. Callow, M.E. Callow, A.B. Brennan, Investigating the energetics of bioadhesion on micro-engineered siloxane elastomers, synthesis and properties of silicones and silicone-modified materials, ACS Symposium Series, 838, 2003, 196-211.

18. M. Kashida, Y. Yamamoto, H. Konno, H. Kishita, US Patent 5132366/1992.

19. P. Plson, US Patent 4472 480/1986.20. R. Koshar, EU Patent 0165 059/1990.21. L. Hoipkemeier-Wilson, J.F Schumacher, M.L.

Carman, A.L Gibson, A.W. Feinberg, M.E Callow, J. A Finlay, J.A. Callow, A.B. Brennan, Antifouling Potential of Lubricious, Micro-engineered, PDMS Elastomers against zoospores of the green fouling alga Ulva (Enteromorpha), Biofouling, 20, 1, 2004, 53-63.

22. Z.P. Zahng, Y.H. Qi, M. Ba, F.J. Liu, Applications of graphene-based materials in environmental pro-tection and detection, Adv. Mat. Res., 842, 2013, 737-740.

23. M.J. Owen, Siloxane Surface Activity, In Advances in Chemistry#Silicone-Based Polymer Science: a Comprehensive Resource, (Eds J.M. Zeigler, F.W.G. Fearon), Amer. Chem. Society, Washington DC, 1990, p. 705-736.

24. B-M Z Newby, M.K. Chaudhuru, H.R. Brown, Macroscopic evidence of the effect of interfacial slippage on adhesion, Science, 269 (5229), 1995, 1407-1409.

25. H. Homma, T. Kuroyagi, K. Izumi, C.L. Mirley, J. Ronzello, S.A. Boggs, I Diffusion of Low Molecular Weight Siloxane from Bulk to Surface, EEE Trans Dielect. Insul., 6, 1999, 370-375.

26. R.F Brady, I.L Singer, Mechanical factors favoring


237

release from fouling release coatings Biofouling, 15, 1-3, 2000, 73-81.

27. W.A. Finzel, H.L. Vincent, Silicones in Coatings In Federation Series on Coating Technology, Federation of Soc. For Coat. Technol., (Eds D. Brezinski, T. Miranda), Blue Bell, PA, 1996.

28. A. Meyer, R. Baier, C.D. Wood, J. Stein, K. Truby, E. Holm, J. Montemarano, C. Kavanagh, B. Nedved, C. Smith, G. Swain, D.Wiebe, Contact angle anomalies indicate that surface-active eluates from silicone coatings inhibit the adhesive mechanisms of fouling organisms, Biofouling, 22, 6, 2006, 411-423.

29. R.L. Townsin, The ship hull fouling penalty, Biofouling, 19, 2003, 9-15.

30. R.L.Townsin, C.D. Anderson, Fouling Control Coatings Using Low Surface Energy, Foul release Technology. In Advances in Marine Antifouling Coatings and Technologies (Eds. C. Hellio, D.M.Y. Yebra) Woodshead Publishing: Cambridge, UK, 2009, p. 693.

31. T. Vladkova, Surface modification approach to con-

trol biofouling, J.Univ.Chem.Technol.Met. (Sofia), 42, 3, 2007, 249-256.

32. K.A. Dafforn, J.A. Lewis, E.L. Johnston, Antifouling strategies: History and regulation, ecological im-pacts and mitigation, Marine Pollution Bulletin, 62, 2011, 453-465.

33. T. Vladkova, P. Dineff, I. Zlatanof, S. Kathiroly, V. Ramasammy, S. Murthy, Composition Antifouling Coating, WO 2008/074102 A1

34. D. Akuzov, T. Vladkova, F. Brümmer, Some Possibilities to reduce the biofilm formation on transparent siloxane coatings, Coll. Surf. B Biointerf., 104, 2013, 303-312.

35. C.-M. Chan, Polymer Surface Modification and Characterization, SPE Hanser, 1993.

36. R.D. Hamilton, O. Holm-Hansen, Adenosine triphosphate content of marine bacteria, Limnol. Oceanogr., 12, 1967, 319-324.

37. O. Holm-Hansen, R.C. Booth, Determination of microbial biomass in ocean profiles,

38. Limnol. Oceanogr., 11, 1965, 510-515.

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